METHOD AND SYSTEM FOR CURRENT SHARING BALANCE IN THREE-PHASE INPUT SOURCE SYSTEM

Abstract

A system and method for current balancing from a three-phase AC power source is disclosed. The system includes power supply units, each having inputs coupled to one output of the three phase power source, and a neutral conductor. Multiple loads are each coupled to a DC output of one of the power supply units. Each of the loads include a component having adjustable power consumption. A controller is coupled to each of the power supply units and each of the loads. The controller is operable to compare the power consumption of each of the loads to an average value. The controller adjusts the power consumption of at least one of the loads to balance the power consumption between the loads.

Claims

1. A system for current balancing from a three-phase AC power source, the system comprising: a plurality of power supply units, each having inputs coupled to one output of the three phase power source, and a neutral conductor; a plurality of loads, each coupled to a DC output of one of the power supply units, the loads including a component having adjustable power consumption; a controller coupled to each of the plurality of power supply units and each of the plurality of loads, the controller operable to compare the power consumption of each of the loads to a predetermined value, and adjust the power consumption of at least one of the loads to balance the power consumption between the loads.

2. The system of claim 1, wherein the component is a fan, and wherein the fan speed may be adjusted.

3. The system of claim 1, wherein the component is a CPU, and wherein the operating frequency of the CPU may be adjusted.

4. The system of claim 1, wherein each of the power supply units include a power meter.

5. The system of claim 1, wherein the controller is a rack management controller, and each of the power supply units and loads are mounted on a corresponding server.

6. The system of claim 5, wherein the corresponding server includes a baseboard management controller operable to monitor power consumption by the server.

7. The system of claim 6, further comprising a power management bus coupled to the baseboard management controller and the rack management controller.

8. The system of claim 1, wherein the predetermined value is an average current from the three-phase AC power source.

9. A method for insuring current balancing from a three-phase AC power source, the method comprising: coupling an input of each of a plurality of power supply units, to one output of a three-phase AC power source and a neutral conductor; coupling a DC output of each of the plurality of power supply units to a plurality of loads; determining power consumption of each of the plurality of loads, each of the loads including a component having adjustable power consumption; comparing the power consumption of each of the loads to a predetermined value, via a controller coupled to each of the plurality of power supply units and each of the plurality of loads; and adjusting the power consumption of at least one of the components of one the loads to balance the power consumption between the loads.

10. The method of claim 9, wherein the component is a fan, and wherein adjusting the power consumption includes adjusting a fan speed of the fan.

11. The method of claim 9, wherein the component is a CPU, and wherein the adjusting the power consumption includes adjusting the operating frequency of the CPU.

12. The method of claim 9, wherein each of the power supply units include a power meter.

13. The method of claim 9, wherein the controller is a rack management controller, and each of the power supply units and loads are mounted on a corresponding server.

14. The method of claim 13, wherein the corresponding server includes a baseboard management controller operable to monitor power consumption by the server.

15. The method of claim 14, wherein the adjusting the power consumption includes the controller sending a signal via a power management bus coupled to the baseboard management controller.

16. The method of claim 9, wherein the predetermined value is an average current from the three-phase AC power source.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The disclosure will be better understood from the following description of exemplary embodiments together with reference to the accompanying drawings, in which:

[0014] FIG. 1 is a prior art system with separated power supplies causing the potential for unbalanced loads;

[0015] FIG. 2 is a block diagram of a prior art system with power supplies on a common power shelf that includes a circuit that balances the loads;

[0016] FIG. 3A is block diagram of an example system that allows current balancing without a specialized circuit;

[0017] FIG. 3B is a block diagram of one of the loads in the system in FIG. 3A; and

[0018] FIG. 4 is a flow diagram the routine to insure proper current balancing between loads.

[0019] The present disclosure is susceptible to various modifications and alternative forms. Some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0020] The present inventions can be embodied in many different forms. Representative embodiments are shown in the drawings, and will herein be described in detail. The present disclosure is an example or illustration of the principles of the present disclosure, and is not intended to limit the broad aspects of the disclosure to the embodiments illustrated. To that extent, elements and limitations that are disclosed, for example, in the Abstract, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference, or otherwise. For purposes of the present detailed description, unless specifically disclaimed, the singular includes the plural and vice versa; and the word including means including without limitation. Moreover, words of approximation, such as about, almost, substantially, approximately, and the like, can be used herein to mean at, near, or nearly at, or within 3-5% of, or within acceptable manufacturing tolerances, or any logical combination thereof, for example.

[0021] The below described method and system senses current from a three phase AC source to different loads. If an imbalance of current is detected, a controller, such as a rack management controller, adjusts the power consumption of one or more of the loads, to adjust the current to a predetermined level such as a desired average current from the three phases of the AC current source.

[0022] FIG. 3A shows an example system 100 that allows load balancing without a current balancing circuit. The system 100 includes three AC phase input sources 102a, 102b, and 102c. Each of the AC phase input sources 102a, 102b, and 102c are at a different phase, and are combined with a common neutral input 104 to provide corresponding AC inputs 106a, 106b, and 106c to one of three power supply units 112, 114, and 116. Each of the power supply units 112, 114, and 116 convert AC power from one of the AC phase input sources 102a, 102b, and 102c to DC power. The power supply units 112, 114, and 116, each have corresponding power meters 120, 122, and 124. The outputs of the power meters 120, 122, and 124 are coupled to a controller, which in this example is a rack management controller 126.

[0023] In this example, each of the power supply units 112, 114, and 116 supply DC power to a corresponding power consuming load such as server loads 130, 132, and 134. The server loads 130, 132, and 134 all have corresponding cooling mechanisms such as a fan wall or corresponding fans 140, 142, and 144, for cooling electronic components in the respective server. The rack management controller 126 may control the speed of the fans 140, 142, and 144. A communication bus 146 allows internal controllers on the server loads 130, 132, and 134, to communicate operational data of the server to the rack management controller 126. In this example, the communication bus 146 is an IPMI communication bus. The rack management controller 126 may be connected to a power management bus 148 to receive data from the power meters 120, 122, and 124.

[0024] Depending on the components in the server loads 130, 132, and 134, as well as the operation of the system 100, the server loads 130, 132, and 134 may consume different power levels. As such there may be load imbalance between the loads. For example, if the server loads 130, 132, and 134 have components that require different levels of power, there may be a load imbalance. Further, if one of the server loads is operating at a higher level, it may require more power. The corresponding fan may also consume more power to cool the active server load.

[0025] FIG. 3B is a block diagram of certain load components 130 in the system 100 shown in FIG. 3A. The system 100 (from FIG. 3A) may be a rack having different servers such as a server 160 shown in FIG. 3B that includes the power supply unit 112, the fan 140, and the server load 130. The power supply unit 112 receives the phased AC current input 106a that is coupled to current at one phase and the neural conductor line 104 in FIG. 3A. The power supply unit 112 converts the received AC power from the AC current input 106a to a DC output rail 162 that provides power to components of the server load 130. In this example, the server load 130 includes a CPU 170, a storage device 172 such as a hard disk drive (HDD) or solid state drive (SSD), and a card device 174. The server 160 includes a baseboard management controller 180 that monitors operational data from the server 160, including power consumption from sensing voltage levels of the DC output rail 162. For simplicity of illustration, only one CPU, one storage device, and one card device is shown. Servers may include multiple different types of each device, or multiple devices, such as 2 or 4 CPUs, multiple storage devices, and multiple card devices, depending on the type of server. Each server represented by the server loads 130, 132, and 134 in FIG. 3A may also each have different numbers of each device from each other.

[0026] In this example, the baseboard management controller 180 is connected via the communication bus 146 (from FIG. 3A) to the rack management controller 126. Thus, the rack management controller 126 may receive operational data for the server 160 from the baseboard management controller 180 via the bus 146, as well as operational data from the power supply unit 112 via the power management bus 148. As will be explained below, the rack management controller may then send commands via the bus 146 to the baseboard management controller 180 to regulate power consumption of the server load 130.

[0027] To decrease the effects of unbalanced loads, several actions can be taken by the system 100. The first and most basic solution is to rearrange or redistribute the loads in such a way that the system 100 becomes more balanced.

[0028] In the components of the system 100 shown in FIGS. 3A-3B, a controlled method of current sharing involves using the rack management controller 126 to monitor the supply current by reading the output of the internal power meters 120, 122, and 124 in each power supply unit 112, 114, and 116. The rack management controller 126 compares the outputs of the power meters 120, 122, and 124 to an average current required from each power supply in real time.

[0029] In this example, the rack management controller 126 may adjust the loading on each of the power supply units 112, 114, and 116, by increasing or decreasing the fan speed of one or more of the respective fans 140, 142, and 144 until the supply current for the respective power supply units 112, 114, and 116 matches the required value. The speed of the fans 140, 142, and 144, is proportional to the current required by the respective server loads 130, 132, and 134. In this manner, input current will be balanced in the three-phase system 100 once loading is balanced between the servers 130, 132, and 134.

[0030] The PSU 112 shown in FIG. 3B may communicate with the RMC 126 via a power management communication bus 148. The power management communication bus 148 may be PMbus, a bus serial peripheral interface (SPI) bus, an inter-integrated circuit (I2C) bus, a controller area network (CAN) bus, or a bus that supports an Electronic Industries Alliance (EIA), RS-232, RS-422, or RS-485 standard. In this example, the meters 120, 122, and 124 of respective power supply units 112, 114, and 116 in FIG. 3A update their status including input voltage, input current, and input power to the rack management controller 126 via the power management bus 148. Each power supply unit, such as the power supply unit 112, may also update status to the respective BMC, such as the BMC 180 in FIG. 3B, via the power management bus 148. In this manner, the rack management controller 126 can adjust power consumption for each individual server load by sending commands to the appropriate BMC via the IPMI management bus. For example, the rack management controller may reduce the load of the server load 130 by sending a command to the BMC 180 to reduce the fan speed of the fan 140.

[0031] In this example, the rack management controller 126 adjusts the current requirements by adjusting fan speed such that the three power supply units 112, 114, and 116 share the load so that input current sharing between the loads meets the requirements in the plus or minus 10% reasonable tolerance. When new loads are added, the system may have a momentary unbalance, but this situation does not serious system operation. Input current of a three-phase source system would achieve balance. The fan speed of each server and CPU switching frequency of each server may be increased or decreased via BMC or RMC commands to achieve a current balance of the system output load. The control method for a PCU is similar to fan speed control. When system loading imbalance occurs, the CPU is operated at a throttling mode, which runs the CPU at a lower speed, keeps it cooler, and uses less power. This occurs because power use in a CPU is linear with clock frequency.

[0032] For example, if the power consumption of the server load 130 is sensed as 65 W, and the power consumption of the server loads 132 and 134 is sensed as 50 W, the rack management controller 126 will determine an imbalance situation. In this example, the rack management controller 126 may reduce the fan speed of the fan 140 so the power consumption of the server load is reduced to 55W, which is within 10% of the desired average power consumption level of 50W. In another example, if the power consumption of the server loads 130 and 132 is sensed as 60 W, and the power consumption of the server load 134 is sensed as 50 W, the rack management controller 126 will determine an imbalance situation. In this example, the rack management controller 126 may reduce the fan speed of the fans 140 and 142 so the power consumption of the server loads 130 and 132 is reduced to 55W, which is within 10% of the desired average power consumption level of 50W.

[0033] A flow diagram in FIG. 4 is representative of example machine readable instructions for current load balancing in the system 100 in FIGS. 3A-3B. In this example, the machine readable instructions comprise an algorithm for execution by: (a) a processor; (b) a controller; and/or (c) one or more other suitable processing device(s). The algorithm may be embodied in software stored on tangible media such as flash memory, CD-ROM, floppy disk, hard drive, digital video (versatile) disk (DVD), or other memory devices. However, persons of ordinary skill in the art will readily appreciate that the entire algorithm and/or parts thereof can alternatively be executed by a device other than a processor and/or embodied in firmware or dedicated hardware in a well-known manner (e.g., it may be implemented by an application specific integrated circuit [ASIC], a programmable logic device [PLD], a field programmable logic device [FPLD], a field programmable gate array [FPGA], discrete logic, etc.). For example, any or all of the components of the interfaces can be implemented by software, hardware, and/or firmware. Also, some or all of the machine readable instructions represented by the flowcharts may be implemented manually. Further, although the example algorithm is described with reference to the flowchart illustrated in FIG. 4, persons of ordinary skill in the art will readily appreciate that many other methods of implementing the example machine readable instructions may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined.

[0034] As shown in FIG. 4, the RMC 126 communicates with the power supply units via the power management bus 148 (400). Each of the power supply units then update their current power output status to the rack management controller 126 (402). The rack management controller 126 then checks current sharing accuracy based on whether the currents from the phased inputs are within an acceptable variance of each other (404). In this example, the current for each phased input are within an acceptable variance if they are within 10% of the average current. If the input currents are sufficiently balanced, the routine loops back to communicating with the BMCs (400). If the input currents are not balanced, the rack management controller 126 controls the fans to increase or decrease power consumption at a level that will balance the currents of the power supplies within the acceptable tolerance (406). The routine then loops back to communicating with the BMCs (400).

[0035] As used in this application, the terms component, module, system, or the like, generally refer to a computer-related entity, either hardware (e.g., a circuit), a combination of hardware and software, software, or an entity related to an operational machine with one or more specific functionalities. For example, a component may be, but is not limited to being, a process running on a processor (e.g., digital signal processor), a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a controller, as well as the controller, can be a component. One or more components may reside within a process and/or thread of execution, and a component may be localized on one computer and/or distributed between two or more computers. Further, a device can come in the form of specially designed hardware; generalized hardware made specialized by the execution of software thereon that enables the hardware to perform specific function; software stored on a computer-readable medium; or a combination thereof.

[0036] The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the invention. As used herein, the singular forms a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms including, includes, having, has, with, or variants thereof, are used in either the detailed description and/or the claims, such terms are intended to be inclusive in a manner similar to the term comprising.

[0037] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. Furthermore, terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0038] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Although the invention has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur or be known to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.