CONTROLLING A COOLING SYSTEM WATER INTAKE PUMP OF AN ELECTRIC MARINE VESSEL

Abstract

According to embodiments of the present disclosure, various methods, apparatuses, and computer program products for controlling a cooling system water intake pump of an electric marine vessel are described herein. In some aspects, a pump controller receives information describing an operating state of an electric propulsion device of a marine vessel, where the information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion system. The pump controller controls a water intake pump of a cooling system for the electric propulsion device based on the received information.

Claims

1. A method of controlling a cooling system water intake pump of an electric marine vessel, the method comprising: receiving information describing an operating state of an electric propulsion device of a marine vessel, wherein the information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion device; and controlling, based on the information, a water intake pump of a cooling system for the electric propulsion device.

2. The method of claim 1, wherein the motor speed is indicated by a rotational speed of the electric motor.

3. The method of claim 1, wherein the temperature readings indicate a temperature of at least one of the electric motor and an inverter.

4. The method of claim 1, wherein the water intake pump includes an impeller that draws ambient water from a body of water into the cooling system; and wherein controlling the water intake pump includes controlling a rotational speed of the impeller.

5. The method of claim 4, wherein the rotational speed of the impeller is limited based on cooling requirements of the electric motor.

6. The method of claim 1, wherein the electric propulsion device is an outboard motor.

7. The method of claim 1, wherein the water intake pump is mechanically isolated from a drive shaft of the electric propulsion device.

8. The method of claim 1 further comprising: controlling the electric motor based on an operational state of the water intake pump.

9. The method of claim 8, wherein a power output of the electric motor is limited in response to detecting that the water intake pump is not operating.

10. An apparatus for controlling a cooling system water intake pump of an electric marine vessel, the apparatus comprising: a water intake pump of a cooling system for an electric propulsion device of a marine vessel; a controller configured to: receive information describing an operating state of the electric propulsion device, wherein the information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion device; and controlling, based on the information, the water intake pump.

11. The apparatus of claim 10, wherein the motor speed is indicated by a rotational speed of the electric motor.

12. The apparatus of claim 10, wherein the temperature readings indicate a temperature of at least one of the electric motor and an inverter.

13. The apparatus of claim 10, wherein the water intake pump includes an impeller that draws ambient water from a body of water into the cooling system; and wherein controlling the water intake pump includes controlling a rotational speed of the impeller.

14. The apparatus of claim 13, wherein the rotational speed of the impeller is limited based on cooling requirements of the electric motor.

15. The apparatus of claim 10, wherein the electric propulsion device is an outboard motor.

16. The apparatus of claim 10, wherein the water intake pump is mechanically isolated from a drive shaft of the electric propulsion device.

17. A computer program product comprising: a set of one or more computer readable storage media; and computer program instructions, collectively stored in the set of one or more storage media, that when executed cause a processor to perform computer operations comprising: receiving information describing an operating state of an electric propulsion device of a marine vessel, wherein the information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion device; and controlling, based on the information, a water intake pump of a cooling system for the electric propulsion device.

18. The computer program product of claim 17, wherein the water intake pump includes an impeller that draws ambient water from a body of water into the cooling system; and wherein controlling the water intake pump includes controlling a rotational speed of the impeller.

19. The computer program product of claim 18, wherein the rotational speed of the impeller is limited based on cooling requirements of the electric motor.

20. The computer program product of claim 17, wherein the water intake pump is mechanically isolated from a drive shaft of the electric propulsion device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1A sets forth a block diagram of an example vessel for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0006] FIG. 1B sets forth a block diagram of an example marine propulsion system for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0007] FIG. 1C sets forth a block diagram of an example high voltage battery for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0008] FIG. 1D sets forth a block diagram of an example power distribution unit for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0009] FIG. 1E sets forth a block diagram of an example vessel control unit for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0010] FIG. 2 sets forth a block diagram of an example electric propulsion system for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0011] FIG. 3 sets forth a flow chart of an example method for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

[0012] FIG. 4 sets forth a flow chart of another example method for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure.

DETAILED DESCRIPTION

[0013] Advances in battery technology have paved the way for full-electric vehicles. Building on those advances, technology to enable full-electric watercraft has been widely adopted. However, the challenges of designing electric vehicles are different from the challenges of designing electric boats. The transformation of existing watercraft platforms to a full-electric platform also poses a different set of challenges.

[0014] In a conventional internal combustion engine (ICE) marine outboard motor, a pump in a lower unit of the outboard motor situated below the water line draws ambient water into the motor's cooling system for cooling engine components. Circulation lines in the cooling system circulate the cooling water throughout the engine block and other engine components. Heat is exchanged between the engine components and the cooling water, and the heated water is then pumped back into the ambient water supply. Typically, a cooling system water intake pump includes an impeller that is driven by the same drive shaft that drives the outboard propeller. Rotation of the drive shaft rotates the impeller to create suction to pump the water into the cooling system. As the engine speed increases, thus generating more heat, the pump speed also increases due to the faster rotation of the drive shaft, thus supplying a greater flow of water to cool the engine. Because the pump impeller is mechanically coupled to the drive shaft, the pump runs continuously as long as the engine is idling, even if no mechanical power is applied to the propeller (i.e., the propeller gearbox is in neutral). Similarly, if the engine is off, the cooling system pump is also off. This mechanism for controlling the cooling system intake pump is not well-suited for electric marine vessels.

[0015] Because electric marine motors do not rely on internal combustion, such motors do not have an idle state in which the drive shaft is continuously spinning. Rather, when no mechanical power is required of the motor, electrical current delivered to the electric motor ceases and the electric motor simply stops. As such, a cooling system intake pump coupled to the drive shaft would not operate while the electric motor is stopped. However, it may be advantageous to continue to cool the electric motor even when the motor has momentarily stopped. Moreover, electric motors are substantially quieter than ICE systems. Thus, the operation of a cooling system pump that is coupled to a drive shaft may, at times, produce a substantial amount of audible noise. When not masked by ICE motor noise, the noise generated by the operation of the intake pump is readily perceptible, and an otherwise silent boating experience afforded by the electric motor is impeded upon by the noise of the cooling system intake pump. At times, the cooling needs of the electric propulsion system may not require the impeller of the intake pump to rotate as the same speed as the drive shaft. At these times, the intake pump is generating an unnecessary amount of noise. It is therefore advantageous to mechanically decouple the intake pump from the drive shaft of the propulsion system and operate the cooling system intake pump independently based on the cooling needs of the electric propulsion system.

[0016] To address these and other issues, controlling a cooling system water intake pump of an electric marine vessel in accordance with the present disclosure provides a cooling system intake pump that is decoupled from the drive shaft and controlled independently based on the cooling needs of the electric motor. The cooling system intake pump is controlled in response to data describing the state of the electric propulsion system, such as data describing temperature readings, cooling system water flow rate, mechanical speed of the motor, pump impeller speed, and other state information that will be described in more detail below. Thus, the intake pump control system described herein mitigates unnecessary acoustic noise generated by the operation of the intake pump. Further, the intake pump control system described herein extends the life of the intake pump.

[0017] FIG. 1A sets forth an example electric vessel 100 for controlling a cooling system water intake pump of an electric marine vessel in accordance with the present disclosure. FIG. 1A is provided to emphasize the powertrain components of vessel 100. It will be appreciated that vessel 100 may include other components not shown or described herein. Vessel 100 may be any type of watercraft. In a particular example, vessel 100 includes a full-electric powertrain and thus may also referred to as an electric boat. To that end, vessel 100 includes a marine propulsion system 102. For example, marine propulsion system 102 may be a full-electric outboard motor or inboard motor with a propeller, or a full-electric jet craft with an impeller. The marine propulsion system is described in more detail below with reference to FIG. 1B.

[0018] The marine propulsion system 102 is powered by one or more high voltage batteries 103. In the example, of FIG. 1A, two high voltage batteries 103 are shown; however, it will be appreciated a vessel 100 in accordance with the present disclosure may include fewer or more high voltage batteries. High voltage batteries operate at voltages ranging from a few hundred to over 800 volts, depending on the design and application. Higher voltages allow for more efficient power transmission and reduced current flow, which helps minimize energy losses. Each high voltage battery 103 includes multiple modules, each containing several individual battery cells connected in series and parallel configurations to achieve the desired voltage and capacity. These cells may be arranged in a pack that optimizes space utilization and facilitates thermal management. Each high voltage battery 103 includes or is coupled to a battery management system (BMS). The BMS is responsible for monitoring and controlling various parameters such as voltage, current, temperature, and state of charge (SoC) of individual cells within the pack. The BMS helps optimize battery performance, protect against overcharging or over-discharging, and ensures safety. The BMS communicates with other vessel components about battery state, receives commands to change the battery state, and controls the opening and closing of the main contactors in the battery. The high voltage battery 103 is described in more detail below with reference to FIG. 1C.

[0019] The marine propulsion system 102 receives power from the high voltage battery 103 via a power distribution unit (PDU) 104. The PDU 104 receives high-voltage DC power from the high voltage batteries 103 and routes it to different subsystems and components within vessel 100, such as the electric marine propulsion system 102 and other subsystems such as a DCDC converter 106. The PDU 104 also couples the high voltage batteries 103 to a charging port 105 for charging the high voltage batteries 103. The PDU 104, as explained in more detail below with reference to FIG. 1D, includes a set of contactors that are controlled by logic or software in the PDU 104 to ensure safety when switching the flow of power among various vessel components.

[0020] The DCDC converter 106 provides voltage conversion capabilities to step down the high-voltage DC power to lower voltages required by an auxiliary system, such as the 12-volt electrical system used for lights, accessories, and onboard electronics. The DCDC converter 106 may be used to charge a lower voltage battery such as a 12-volt marine battery 107.

[0021] Vessel 100 further includes a vessel control unit 108. Vessel control unit 108 serves as the central control unit responsible for managing and coordinating various functions and systems onboard the vessel 100. For example, the vessel control unit 108 can provide propulsion control, including regulating engine speed, torque, and direction to achieve desired propulsion performance and maneuverability in accordance with commands or signals received from the vessel's throttle control 109. The vessel control unit 108 can also manage the vessel's steering system. The vessel control unit 108 can also control startup/shut down routines, control charging/operation mode selection, control the opening and closing of contactors in the PDU 104, monitor the state of onboard systems, perform vessel diagnostics, and interface with an operator dashboard. To that end, the vessel control unit 108 may communicate with the other vessel powertrain components (e.g., the marine propulsion system 102, the high voltage battery 103, the PDU 104, the DCDC converter 106, and so one) via a control area network (CAN), referred to herein as a CAN bus 110. The vessel control unit 108 will be described in more detail below with reference to FIG. 1E.

[0022] The CAN bus 110 may be a two-wire serial bus that allows multiple components and devices within a vessel to communicate with each other without a host computer. The CAN bus 110 may use a message-based communication scheme where components and devices send and receive data in the form of messages. Each message includes a CAN identifier (CAN ID), data bytes, and control bits. The CAN bus 110 may employ a multi-master architecture, in that any device on the network can initiate a message transmission. This distributed architecture allows for efficient communication between vessel components without the need for a centralized controller. In a particular example, the CAN bus 110 may implement the NMEA2000 protocol, a standard set forth by the National Marine Electronics Association. NMEA2000 provides optimization and messaging for a marine environment.

[0023] Vessel 100 can also include a high voltage interlock loop (HVIL) system, which is a safety feature designed to ensure the safe operation and maintenance of the high-voltage components. HVIL is a dedicated circuit that ensures the high voltage connectors are well inserted in the equipment mating connector to ensure the safety of the high voltage connections. HVIL is used by the high voltage battery BMS and the vessel control unit 108 to confirm the integrity of these connections before applying high voltage energy to each high voltage device in the vessel.

[0024] For ease of reference, in FIG. 1A power interconnects 111 supplying high voltage power are shown in hash-filled lines, data interconnects for CAN bus 110 are shown in thick solid black lines, and HVIL interconnects 113 are shown in dashed lines.

[0025] For further explanation, FIG. 1B sets forth a block diagram of an example of the electric marine propulsion system 102 in accordance with at least one embodiment of the present disclosure. The example marine propulsion system 102 of FIG. 1B includes a CAN interface 121 for coupling the marine propulsion system 102 to the CAN bus 110. For example, the CAN interface 121 may be a network interface controller configured to send and receive messages in the form of CAN frames over the CAN bus 110.

[0026] The example marine propulsion system 102 also includes a controller 122 coupled to the CAN interface 121. The controller 122 may include or implement a processor, a microcontroller, an Application Specific Integrated Circuit (ASIC), a programmable logic array (PLA) such as a field programmable gate array (FPGA), or other data processing unit in accordance with the present disclosure. In some examples, the controller is implemented by a processor or central processing unit configured to execute computer programming instructions, also referred to a computer executable instructions or processor executable instruction. Such instruction can be loaded from and stored in one or more memory devices collectively referred to as storage 123. Storage 123 may include electrically erasable programmable read-only memory (EEPROM) such as Flash memory (e.g., NAND and NOR flash memory or other types of solid-state memory), dynamic random-access memory (DRAM), static RAM (SRAM), magnetic disk storage, and the like. The storage 123 may be integrated with the controller 122 or provided as a separate memory device coupled to the controller 122.

[0027] The marine propulsion system 102 also includes an inverter 129 that that is powered by the high voltage batteries 103. The inverter 129 functions to convert the DC current received from the high voltage batteries 103 to alternating current (AC) that can be used by an electric motor. In some examples, the inverter 129 is a high voltage two-phase DC to a high voltage three-phase AC converter. The marine propulsion system also includes an electric motor 124 coupled to a propeller/impeller 125. The electric motor 124 is powered by the current received from the inverter 129. The electric motor 124 is an electric traction motor that turns a drive shaft (not shown) that drives the propeller/impeller 125. In some examples, the electric motor is a permanent magnet electric motor. The electric motor 124 is designed to withstand exposure to water and corrosive marine environments, featuring waterproof enclosures, sealed bearings, and corrosion-resistant materials to ensure reliable operation in wet conditions. The electric motor 124 operates quietly, producing minimal noise and vibration compared to traditional combustion engines, which contributes to a quieter boating experience as well as reduced noise pollution in aquatic environments. The electric motor 124 offers high efficiency and energy density, allowing electric boats to achieve comparable performance to traditional boats powered by combustion engines while using less energy and producing fewer emissions.

[0028] A control program 127 embodied in computer programing instructions is stored within tangible persistent storage of storage 123. When executed by the controller 122, the control program 127 is configured to receive commands from the vessel control unit 108 and control the electric motor 124 in accordance with those commands. For example, the control program 127 may be configured to regulate the distribution of electrical energy from the inverter 129 to the electric motor 124. In this example, the control program 127 may receive a throttle/speed command from the vessel control unit 108 and determine the frequency variation or voltage variation that will enter the electric motor 124 for controlling the vessel's speed. The control program 127 is further configured to receive motor state information from various sensors (not shown) and supply motor state information and diagnostic information to the vessel control unit 108. Also stored in tangible persistent storage of storage 123 is a pump controller program 126 for controlling a cooling system water intake pump of the marine propulsion system. The pump controller program 126 receives information describing an operating state of an electric propulsion device of a marine vessel. The information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion system. The pump controller program 126 controls a water intake pump of a cooling system for the electric propulsion device based on the received information. Additional aspects of the pump controller will be described in more detail below.

[0029] For further explanation, FIG. 1C sets forth a block diagram of an example of the high voltage battery 103 in accordance with at least one embodiment of the present disclosure. The example high voltage battery 103 of FIG. 1C includes a CAN interface 131 for coupling the high voltage battery 103 to the CAN bus 110. For example, the CAN interface 131 may be a network interface controller configured to send and receive messages in the form of CAN frames over the CAN bus 110. The example high voltage battery 103 includes array of battery cells 135 organized into battery modules 140 or battery packs, and a set of battery contactors 137 that selectively couple the battery modules 140 to high voltage terminals 138 of the battery 103.

[0030] The example high voltage battery 103 also includes a battery management system (BMS) 134 comprising a controller 132 coupled to the CAN interface 131. Controller 132 may include or implement a processor, a microcontroller, an ASIC, PLA such as an FPGA, or other data processing unit in accordance with the present disclosure. In some examples, controller 132 is implemented by a processor or central processing unit configured to execute computer programming instructions, also referred to a computer executable instructions or processor executable instruction. Such instructions can be loaded from and stored in one or more memory devices collectively referred to as storage 133. Storage 133 may include EEPROM such as Flash memory (e.g., NAND and NOR flash memory or other types of solid-state memory), DRAM, SRAM, magnetic disk storage, and the like. The battery management system 134 further includes a variety of sensors (not shown) coupled to battery cells for measuring battery state information. The storage 133 may be integrated with the controller 132 or provided as a separate memory device coupled to the controller 132.

[0031] The BMS 134 includes a control program 139 embodied in computer programing instructions stored in tangible persistent storage of storage 133. In some examples, the control program 139 controls the state of the battery contactors for selectively coupling and decoupling the battery modules 140 to the high voltage terminals 138 of the battery 103. In some examples, the control program 139 also monitors battery state information such as voltage, current, and temperature in battery cells 135 via the above-mentioned sensors. In some examples, the control program 139 also communicates with the vessel control unit 108 to provide battery state information. The control program also controls the charging of the battery cells 135.

[0032] For further explanation, FIG. 1D sets forth a block diagram of an example of the PDU 104 in accordance with at least one embodiment of the present disclosure. The example PDU 104 of FIG. 1D includes a CAN interface 141 for coupling the PDU 104 to the CAN bus 110. For example, the CAN interface 141 may be a network interface controller configured to send and receive messages in the form of CAN frames over the CAN bus 110. The PDU 104 also includes a battery interface 144 coupling the high voltage batteries 103 to a switching system 145 of the PDU 104, a charge port interface 150 coupling the charging port 105 to the switching system 145, a motor interface 147 coupling the marine propulsion system 102 to the switching system 145, and a DCDC interface 148 coupling the DCDC converter 106 to the switching system 145. The switching system 145 includes a set of contactors (not shown for simplicity) by which the PDU 104 supplies power from the high voltage batteries 103 to the marine propulsion system 102 and to the DCDC converter 106, or supplies power from the charging port 105 to the high voltage batteries 103.

[0033] The example PDU 104 also includes a controller 142 that may include or implement a processor, a microcontroller, an ASIC, PLA such as an FPGA, or other data processing unit in accordance with the present disclosure. In some examples, the controller 142 is implemented by a processor or central processing unit configured to execute computer programming instructions, also referred to a computer executable instructions or processor executable instruction. Such instructions can be loaded from and stored in one or more memory devices collectively referred to as storage 143. Storage 143 may include EEPROM such as Flash memory (e.g., NAND and NOR flash memory or other types of solid-state memory), DRAM, SRAM, magnetic disk storage, and the like. The storage 143 may be integrated with the controller 142 or provided as a separate memory device coupled to the controller 122.

[0034] The PDU 104 also includes a control program 149 embodied in computer programing instructions stored in tangible persistent storage of storage 143. When executed by the controller 142, the control program 149 is configured to receive commands from the vessel control unit 108 and control the switching system 145 to connect and disconnect power supplied to vessel components. The control program 149 is also configured to provide state information to vessel control unit 108.

[0035] For further explanation, FIG. 1E sets forth a block diagram of an example of vessel control unit 108 in accordance with at least one embodiment of the present disclosure. The example vessel control unit 108 of FIG. 1E includes a CAN interface 151 for coupling the vessel control unit 108 to the CAN bus 110. For example, the CAN interface 151 may be a network interface controller configured to send and receive messages in the form of CAN frames over the CAN bus 110.

[0036] The example vessel control unit 108 also includes a controller 152 that may include or implement a processor, a microcontroller, an ASIC, PLA such as an FPGA, or other data processing unit in accordance with the present disclosure. In some examples, controller 152 is implemented by a processor or central processing unit configured to execute computer programming instructions, also referred to a computer executable instructions or processor executable instruction. Such instructions can be loaded from and stored in one or more memory devices collectively referred to as storage 153. Storage 153 may include EEPROM such as Flash memory (e.g., NAND and NOR flash memory or other types of solid-state memory), DRAM, SRAM, magnetic disk storage, and the like. The storage 153 may be integrated with the controller 152 or provided as a separate memory device coupled to the controller 152.

[0037] The vessel control unit 108 also includes a control program 154 embodied in computer programing instructions stored in tangible persistent storage of storage 153. When executed by controller 152, the control program 154 is configured to send commands to other vessel components and receive state information and diagnostic data from vessel components as discussed above.

[0038] For further explanation, FIG. 2 sets forth a block diagram of an example electric propulsion device 200 for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure. In some examples, the electric propulsion device 200 is an outboard motor, as depicted. However, it will be appreciated that the electric propulsion device 200 may be other types of marine propulsion devices. Where the electric propulsion device 200 is an outboard motor, the electric propulsion device 200 may be partitioned into an upper unit 240, a middle unit 242, and a lower unit 244. The example electric propulsion device 200 may be similar to the marine propulsion system 102 in FIGS. 1A and 1B. For example, the electric propulsion device 200 includes an inverter 202 that supplies electrical energy to an electric motor 204. The electric motor 204 turns a vertical drive shaft 206 that is coupled via a coupler 210 to a horizontal propeller shaft 208 that drives a propeller 209.

[0039] The electric propulsion device 200 also includes a cooling system that is comprised of a water intake pump 212 that pumps ambient water into cooling system via an inlet 213. The cooling system also includes water distribution lines 214 that circulate the water around the components of the electric propulsion device 200 such as the inverter 202 and electric motor 204. In some examples, the cooling system may include water jackets or other structures that bring the water in the distribution lines 214 into thermal contact with the electric propulsion system components. The cooling system also includes one or more water temperature sensors 216 that report temperature readings of the water in the distribution lines 214. The cooling system also includes one or more flow rate sensors 217 that detect the rate of flow of the water in the distribution lines 214. The electric propulsion device 200 also includes one or more temperature sensors 218 located on or proximate to the inverter 202 and the electric motor 204. The temperature sensors 218 may report temperature readings of a contact surface (e.g., the electric motor casing) or ambient temperature. The electric propulsion device 200 also includes a motor speed sensor 219 configured to output the rotational speed of the motor. The electric propulsion device 200 also includes one or more current sensors that output a reading of the electric current at various points in a power distribution system, including a current sensor 215 that outputs a reading of the current applied by the inverter 202 to the electric motor 204. The current sensor can be, for example, a sensor in the inverter 202.

[0040] The electric propulsion device 200 also includes a controller 220. The controller 220 is configured to receive commands from the vessel control unit and control the inverter 202 in accordance with those commands. For example, controller 220 may be configured to regulate the distribution of electrical energy from the inverter 202 to the electric motor 204. In this example, controller 220 may receive a throttle/speed command from the vessel control unit and determine the frequency variation or voltage variation that will enter the electric motor for controlling the vessel's speed. The controller 220 is also configured to receive TRIM commands from the vessel control unit and operate a rutter in accordance with the TRIM commands and the TRIM sensor value embedded in the outboard. The controller 220 is also configured to receive state information from various sensors such as the current sensor 215, temperature sensors 216, 218, flow rate sensor 217, and motor speed sensor 219.

[0041] The electric propulsion device 200 also includes a pump controller 222. The pump controller 222 may be an electronic control unit that is separate from the electric propulsion device controller 220 (as depicted), or may be integrated with the electric propulsion device controller 220. For example, the pump controller 222 may be a submodule of the electric propulsion device controller 220. The pump controller 222 receives state information of the electric propulsion device 200, such as data from one or more of the current sensor 215, temperature sensors 216, 218, flow rate sensor 217, and motor speed sensor 219. The pump controller 222 can receive this information directly from the sensors or from other components.

[0042] In a particular example, the pump controller 222 receives information describing a state of an electric propulsion device of a marine vessel, including one or more of the speed of the electric motor 204, the temperature of the electric motor 204, the temperature of the water in the cooling system, the flow rate of water in the cooling system, the temperature of the inverter 202, the electric current supplied by the inverter 202 to the electric motor. In some examples, at least some of the information is collected by sensors in the electric propulsion system. In some implementations, the pump controller 222 receives at least some of the information from other electronic control units, such as the vessel control unit or the electric propulsion device controller. In some examples, the pump controller 222 is coupled to a CAN bus for communication with other vessel components, such as the vessel control unit. In such examples, information describing the state of the electric propulsion device can be received via the CAN bus from other electronic control units.

[0043] The pump controller 222 can detect the motor speed of the electric motor by identifying data or values in the received information that are indicative of motor speed, such as the number of revolutions per minute of the drive shaft in the electric propulsion device. In some implementations, the pump controller 222 can estimate the motor speed based on the amount of current supplied to the electric motor 204. The pump controller 222 can also determine the temperature of one or more components of the electric propulsion device from the received information. For example, the pump controller 222 may identify data indicating the temperature of the electric motor at one or more locations on a motor casing. The pump controller 222 may determine the temperature of the inverter within or outside of the inverter. For example, the pump controller 222 may identify data indicating temperature readings from one or more temperature sensors located on, within, or proximate to the inverter.

[0044] The pump controller 222 controls the water intake pump 212 of the cooling system for the electric propulsion device based on the information from the various sensors discussed above. In some examples, the pump controller 222 controls the water intake pump 212 via a signal line by increasing and decreasing the rotational speed of the pump impeller based on the motor speed of the electric motor. For example, as motor speed increases, the pump controller 222 can increase the pump impeller speed to meet the cooling needs of the inverter and the electric motor. As motor speed decreases, the pump controller 222 can decrease the pump impeller speed as less cooling is needed. When the electric motor is off, the pump controller 222 can continue to run the water intake pump 212 to continue to cool the inverter and electric motor if needed. However, if additional cooling is not needed when the electric motor is off, the pump controller 222 can turn the water intake pump 212 completely off. This alleviates the unwanted noise of the water intake pump when the electric marine vessel is otherwise substantially silent. In a conventional ICE system in which the pump impeller is coupled to the drive shaft, the cooling system is unable to cool the engine while the motor is off, and further the speed of the pump impeller is fixed to the rotational speed of the drive shaft and cannot be reduced.

[0045] In some examples, the rotational speed of the impeller is controlled to be less than the motor speed, i.e., less than the rotational speed of the drive shaft. Because the impeller is mechanically decoupled from the drive shaft, it need not spin at the same rate as the drive shaft if the cooling needs of the electric motor are otherwise met. By operating the impeller at a lower speed, the water intake pump produces less noise than if it were coupled to the drive shaft. As the motor speed of the electric motor increases, the pump controller 222 can increase the rotational speed of the impeller, either linearly or non-linearly, to compensate for the increased heat generated by the electric motor. Should the electric motor require additional cooling (e.g., based on temperature feedback information), the rotational speed of the impeller can be increased independent of the motor speed of the electric motor. Thus, the rotational speed of the impeller is adapted based on the cooling needs of the electric motor, which minimizes the noise generated by the water intake pump 212, rather than fixing the rotational speed of the impeller to the rotational speed of the motor.

[0046] In addition to motor speed, the temperature of the electric motor, the temperature of water in the cooling system, and the flow rate of the water in the cooling system are also indicative of the cooling needs of the electric motor. In some implementations, the pump controller 222 controls the water intake pump 212 based on temperature feedback data by receiving temperature feedback information from an electric motor temperature sensor, an inverter temperature sensor, a cooling system water temperature sensor, or combinations thereof. The pump controller 222 then compensates the rotational speed of the impeller based on the temperature feedback information. For example, the rotational speed of the impeller may be increased in response to an increase in the motor speed of the electric motor. However, if temperature feedback information from a temperature sensor indicates that the temperature of the electric motor or inverter is too hot, the pump controller 222 can control the water intake pump 212 to increase the rotational speed of the impeller. Conversely, if the temperature feedback information from a temperature sensor indicates that the inverter or electric motor temperature is a below a temperature limit by a threshold amount, the pump controller 222 can control the water intake pump 212 to decrease the rotational speed of the impeller, thus minimizing the noise of the water intake pump 212. Temperature feedback information from a water temperature sensor can be used in the same way, where the temperature of the water after heat exchange with the electric motor is indicative of the electric motor temperature. Thus, based on motor speed and temperature information provided in a continuous feedback loop, the pump controller 222 determines the minimum impeller speed needed to ensure that the electric motor is sufficiently cooled, thereby minimizing the noise of the water intake pump 212 and extending the life of the water intake pump 212.

[0047] The water intake pump 212 is a self-priming pump. In some examples, if a flow rate sensor 217 detects that water is not flowing in the cooling system (e.g., due to a broken impeller) with a preconfigured time period (e.g., 10 seconds), the pump controller 222 reports an error and discontinues operation of the pump. In some implementations, the error is reported to the electric propulsion device controller 220. In response to detecting that the water intake pump is non-operational, the electric propulsion device controller 220 can limit the motor speed of the electric motor 204. For example, the electric motor 204 may be rated to run dry (i.e., not cooled) at a particular mechanical power rating or speed rating. In such an example, the controller 222 controls the electric propulsion device such that the electric motor 204 does not exceed this power or speed rating.

[0048] For further explanation, FIG. 3 sets forth a flow chart of an example method for controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure. The example of FIG. 3 includes an electric marine vessel 300. The electric marine vessel includes an electric propulsion device (e.g., a full-electric outboard motor) and high voltage battery packs for supplying electricity to the electric propulsion device. The electric propulsion device includes an inverter that receives power from the battery packs and converts the power into energy that is used to actuate an electric motor. The electric motor drives a propeller of the electric propulsion device via a rotating drive shaft and a coupler. The marine vessel 300 may include additional powertrain components as described above. During operation, the marine vessel is waterborne on a body of water (e.g., an ocean, river, lake, etc.). The inverter, electric motor and other components of the electric propulsion device are cooled via ambient water from the body of water.

[0049] The example of FIG. 3 includes a pump controller 301 of a cooling system water intake pump 307. As discussed above, a water intake pump 307 of a cooling system in an electric propulsion device of a marine vessel draws ambient water from the body of water and circulates the water in areas proximate to the electric motor and other components. The water intake pump 307 includes an impeller, the rotational speed of which is controlled by the pump controller 301. In some examples, the pump controller 301 is a standalone electronic control unit. In other examples, the pump controller may be a module that is integrated into another electronic control unit, such as controller of the marine propulsion device, a vessel control unit, and so on. In some examples, the pump controller is embodied in a set of computer programming instructions that, when executed by a processor of the pump controller, cause the processor to carry out the operations shown in FIG. 3.

[0050] The method of FIG. 3 includes receiving 302 information 303 describing a state of an electric propulsion device of a marine vessel. Information 303 describing the state of the electric propulsion device can include the speed and temperature of the motor, the temperature of the water in the cooling system, the flow rate of water in the cooling system, the current drawn by the electric motor, the amount of throttle applied to the electric motor, and so on. In some examples, at least some of the information 303 is collected by sensors in the electric propulsion system. For example, a motor speed sensor can report the revolutions per minute (RPM) of the electric motor, while a current sensor can report the current draw of the inverter or the current supplied to the electric motor. A flow rate sensor in the cooling system can report the rate of the flow of water through the circulation lines. One or more temperature sensors can report the temperature of the inverter and/or electric motor. One or more cooling system temperature sensors can report the temperature of the water at various points in the cooling system. In some implementations, the pump controller 301 receives 302 at least some of the information 303 directly from these sensors. In some implementations, the pump controller 301 receives 302 at least some of the information 303 from other electronic control units, such as the vessel control unit or the electric propulsion device controller. In some examples, the pump controller 301 is coupled to a CAN bus for communication with other vessel components, such as the vessel control unit. In such examples, information 303 describing the state of the electric propulsion device can be received via the CAN bus from other electronic control units. In some implementations, at least part of the information 303 is received in one or more data messages, packets, or frames.

[0051] In some implementations, the pump controller 301 determines the motor speed of the electric motor by identifying data or values in the received information 303 that are indicative of motor speed. In some implementations, the pump controller 301 determines the motor speed from the information 303 by identifying RPM data in the information 303, such as the number of revolutions per minute of the drive shaft in the electric propulsion device. In some implementations, the pump controller 301 determines the motor speed from the information 303 by identifying data indicating the current drawn by the inverter or electric motor that is reported by one or more electric current sensors. The motor speed can then be estimated based on the amount of current consumed. In some implementations, the pump controller 301 determines the motor speed from the information 303 by identifying data in the information 303 indicating an amount of throttle applied to the electric motor. For example, a throttle command or signal received from a vessel control unit can indicate the amount of throttle applied to the electric motor.

[0052] In some implementations, the pump controller 301 determines the temperature of one or more components of the electric propulsion device by identifying data or values in the received information 303 that are indicative of the temperature of various components. For example, the pump controller 301 may determine the temperature of the electric motor at one or more locations on a motor casing. The information 303 may indicate temperature readings from one or more temperature sensors located on or proximate to the motor casing. In another example, the pump controller 301 may determine the temperature of the inverter within or outside of the inverter. For example, the information may indicate temperature readings from one or more temperature sensors located on, within, or proximate to the inverter.

[0053] The method of FIG. 3 also includes controlling 304, based on the information 303, the water intake pump 307 of the cooling system for the electric propulsion device. In some examples, the pump controller 301 controls 304 the water intake pump 307 by increasing and decreasing the rotational speed of the pump impeller based on the motor speed of the electric motor. For example, as motor speed increases, the pump controller 301 can increase the pump impeller speed to meet the cooling needs of the inverter and the electric motor. As motor speed decreases, the pump controller 301 can decrease the pump impeller speed as less cooling is needed. When the electric motor is off, the pump controller 301 can continue to run the water intake pump 307 to continue to cool the inverter and electric motor if needed. However, if additional cooling is not needed when the electric motor is off, the pump controller 301 can turn the water intake pump 307 completely off. This alleviates the unwanted noise of the water intake pump when the electric marine vessel is otherwise substantially silent. In a conventional ICE system in which the pump impeller is coupled to the drive shaft, the cooling system is unable to cool the engine while the engine is off and conversely the speed of the pump impeller is fixed to the rotational speed of the drive shaft and cannot be reduced.

[0054] In some examples, the rotational speed of the impeller is controlled to be less than the motor speed, i.e., less than the rotational speed of the drive shaft. Because the impeller is mechanically decoupled from the drive shaft, it need not spin at the same rate as the drive shaft if the cooling needs of the electric motor are otherwise met. By operating the impeller at a lower speed, the water intake pump produces less noise than if it were coupled to the drive shaft. As the motor speed of the electric motor increases, the pump controller 301 can increase the rotational speed of the impeller, either linearly or non-linearly, to compensate for the increased heat generated by the electric motor. Should the electric motor require additional cooling (e.g., based on temperature feedback information), the rotational speed of the impeller can be increased independent of the motor speed of the electric motor. Thus, the rotational speed of the impeller is adapted based on the cooling needs of the electric motor, which minimizes the noise generated by the water intake pump 307, rather than fixing the rotational speed of the impeller to the rotational speed of the motor.

[0055] In addition to motor speed, the temperature of the electric motor, the temperature of water in the cooling system, and the flow rate of the water in the cooling system are also indicative of the cooling needs of the electric motor. In some implementations, the pump controller 301 controls 304 the water intake pump 307 based on temperature feedback data by receiving temperature feedback information from an electric motor temperature sensor, an inverter temperature sensor, a cooling system water temperature sensor, or combinations thereof. The pump controller 301 then compensates the rotational speed of the impeller based on the temperature feedback information. For example, the rotational speed of the impeller may be increased in response to an increase in the motor speed of the electric motor. However, if temperature feedback information from a temperature sensor indicates that the temperature of the electric motor or inverter is too hot, the pump controller 301 can control the water intake pump 307 to increase the rotational speed of the impeller. Conversely, if the temperature feedback information from a temperature sensor indicates that the inverter or electric motor temperature is a below a temperature limit by a threshold amount, the pump controller 301 can control the water intake pump 307 to decrease the rotational speed of the impeller, thus minimizing the noise of the water intake pump 307. Temperature feedback information from a water temperature sensor can be used in the same way, where the temperature of the water after heat exchange with the electric motor is indicative of the electric motor temperature. Thus, based on motor speed and temperature information provided in a continuous feedback loop, the pump controller 301 determines the minimum impeller speed needed to ensure that the electric motor is sufficiently cooled, thereby minimizing the noise of the water intake pump 307 and extending the life of the water intake pump 307.

[0056] It will therefore be appreciated that mechanically decoupling the water intake pump from the drive shaft and providing independent control of the water intake pump via a pump controller enhances the electric boating experience by alleviating the noise of the water intake pump. Further, providing independent control of the water intake pump via a pump controller extends the life of the pump by discontinuing the pump when no mechanical power is being supplied by the electric motor.

[0057] For further explanation, FIG. 4 sets forth a flow chart of another example method of controlling a cooling system water intake pump of an electric marine vessel in accordance with at least one embodiment of the present disclosure. The example method of FIG. 4 extends the method of FIG. 3 in that the method of FIG. 4 includes detecting 402 an operational state of the water intake pump 307. In some examples, the pump controller 301 detects 402 an operational state of the water intake pump 307 based on the rotational speed of the impeller and/or a reading from a flow rate sensor in the distribution lines of the cooling system. For example, the operational state of the water intake pump 307 may be that the water intake pump 307, and more particularly the impeller, is not operating. As another example, the operational state of the water intake pump 307 may be that the impeller is rotating at a maximum speed and thus cannot provide additional cooling capability. The pump controller 301 indicates the operational state of the water intake pump to an electronic control unit such as the vessel control unit or an electric propulsion device controller.

[0058] The method of FIG. 4 also includes controlling 404 the electric motor based on an operational state of the water intake pump 307. In some examples, the electronic control unit 401 controls 402 the electric motor in response to detecting an operational state of the water intake pump 307. For example, in response to identifying that the water intake pump 307 is not operating, the electronic control unit 401 limits the motor speed of the electric motor. For example, the electric motor may be rated to run dry (i.e., not cooled) at a particular mechanical power rating. In such an example, the electronic control unit controls the electric propulsion device such that the electric motor does not exceed this power rating. In another example, in response to detecting that the water intake pump 307 is operating at a maximum capability, the electronic control unit may limit the motor speed of the electric motor.

[0059] In view of the foregoing, it will be appreciated that controlling a cooling system water intake pump of an electric marine vessel provides a number of advantages, including general noise reduction for an enhanced boating experience and extension of the operating life of a water intake pump. Two conditions that will shorten the lifespan of a self-prime pump include 1) running the pump continuously and 2) running the pump dry for more than an allowable amount of time (e.g., 20 seconds or other manufacturer specification). In accordance with the embodiments of the present disclosure, activating the water intake pump only when needed extends the lifespan of the pump. Further, the flow rate sensor is used to determine when the pump is running dry and, if so, discontinue the pump to prevent damage to the impeller.

[0060] An embodiment of the present disclosure is directed to a method of controlling a cooling system water intake pump of an electric marine vessel. The method includes receiving information describing an operating state of an electric propulsion device of a marine vessel, where the information indicates at least one of a motor speed of an electric motor and temperature readings within the electric propulsion system. The method also includes controlling, based on the information, a water intake pump of a cooling system for the electric propulsion device. The electric propulsion device may be an outboard motor. In some examples, the motor speed is indicated by a rotational speed of the electric motor. In some examples, the temperature data indicates a temperature of at least one of the electric motor and an inverter.

[0061] In some examples, the water intake pump includes an impeller that draws ambient water from a body of water into the cooling system. Controlling the water intake pump includes controlling the rotational speed of the impeller. In some examples, the rotational speed of the impeller is limited based on cooling requirements of the electric motor. In some examples, the water intake pump is mechanically isolated from a drive shaft of the electric propulsion device.

[0062] In some implementations, the method includes controlling the electric motor based on an operational state of the water intake pump. In these implementations, a power output of the electric motor may be limited in response to detecting that the water intake pump is not operating.

[0063] Various aspects of the present disclosure are described by narrative text, flowcharts, block diagrams of computer systems and/or block diagrams of the machine logic included in computer program product (CPP) embodiments. With respect to any flowcharts, depending upon the technology involved, the operations can be performed in a different order than what is shown in a given flowchart. For example, again depending upon the technology involved, two operations shown in successive flowchart blocks may be performed in reverse order, as a single integrated step, concurrently, or in a manner at least partially overlapping in time.

[0064] A computer program product embodiment (CPP embodiment or CPP) is a term used in the present disclosure to describe any set of one, or more, storage media (also called mediums) collectively included in a set of one, or more, storage devices that collectively include machine readable code corresponding to instructions and/or data for performing computer operations specified in a given CPP claim. A storage device is any tangible device that can retain and store instructions for use by a computer processor. Without limitation, the computer readable storage medium may be an electronic storage medium, a magnetic storage medium, an optical storage medium, an electromagnetic storage medium, a semiconductor storage medium, a mechanical storage medium, or any suitable combination of the foregoing. Some known types of storage devices that include these mediums include: diskette, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanically encoded device (such as punch cards or pits/lands formed in a major surface of a disc) or any suitable combination of the foregoing. A computer readable storage medium, as that term is used in the present disclosure, is not to be construed as storage in the form of transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide, light pulses passing through a fiber optic cable, electrical signals communicated through a wire, and/or other transmission media. As will be understood by those of skill in the art, data is typically moved at some occasional points in time during normal operations of a storage device, such as during access, de-fragmentation or garbage collection, but this does not render the storage device as transitory because the data is not transitory while it is stored.

[0065] The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.