A safety switching system and method for braking an electric motor in a mobile device. A multi-phase shorting system brakes the motor by diverting power from the motor windings. Multiple independent switching units each include a switch control unit controlling multiple normally-closed switches which, in response to a safety controller, close to connect a respective motor winding to electrical ground. An electromechanical brake system mechanically brakes the motor. An independent switching unit includes two normally-open switches which, in response to the safety controller, opens to activate an electromechanical brake. A feedback system communicates to the safety controller a switch failure of any of the switches either as a short circuit fault or an open circuit fault. The feedback system may include an analog and/or a digital feedback system. If a switch failure is detected, the safety controller may activate the multi-phase shorting system and the electromechanical brake system.

An overcurrent protection circuit for a motor, where the overcurrent protection circuit includes: a first input configured to receive a first drive signal for the motor; a second input configured to receive an adjustable overcurrent protection threshold; a third input configured to receive a current detection value indicative of an amount of current flowing through the motor; an overcurrent detection module, which is configured to: connect to the second input to obtain a first comparison value related to the overcurrent protection threshold; connect to the third input to obtain a second comparison value related to the detection value; and compare the first comparison value to the second comparison value to generate a comparison output that characterizes the presence or absence of an overcurrent state.

A current limiting device includes a current limiter to limit a current to be carried to a drive within a range of a current limit value. The current limit value is set to change according to an acceleration of the drive.

A motor drive device includes a first drive circuit to control an energization period of a first upper arm switch and a first lower arm switch connected to one end of a coil, a second drive circuit to control an energization period of a second upper arm switch and a second lower arm switch connected to another end of the coil, a current detection circuit to detect current flowing through the coil and output a current detection signal indicating a detection result of the current, a first protection circuit to determine whether overcurrent has occurred based on the current detection signal and output a first enable signal indicating a determination result to the first drive circuit, and a second protection circuit to determine whether overcurrent has occurred based on the current detection signal and output a second enable signal indicating a determination result to the second drive circuit.

A motor drive control device capable of determining a drive state of a motor is provided. The motor drive control device includes a plurality of motor drive circuits performing, based on drive control signals (Sca1 and Sca2) for controlling the number of rotations of a motor, control of energization of the motor and outputting FG signals (fg1 and fg2) having a cycle corresponding to the actual number of rotations of the motor, a composite signal generation circuit receiving an input of each of the FG signals output from the motor drive circuits and generating a composite signal by combining input signals, and a drive control circuit generating, based on a speed command signal indicating a target number of rotations of the motor, the drive control signals and outputting the drive control signals to each of the motor drive circuits. The FG signals output from the motor drive circuits have a phase difference from each other.

One aspect of a motor control device according to the present invention is a motor control device that controls a motor of an electric pump. The motor control device includes a drive unit that supplies a drive current to the motor; a control unit that controls a rotation speed of the motor by controlling the drive unit based on a rotation speed command value; and a current detection unit that detects the drive current supplied to the motor, and supplies a current detection value indicating a detection result of the drive current to the control unit. The control unit determines whether or not a foreign fluid suction abnormality occurs in the electric pump, based on a first current detection value acquired at a first timing when the rotation speed command value changes from a first command value to a second command value and a second current detection value acquired after the first timing.

An electronically commutated motor driving module for driving a motor includes a voltage detector, an electronically commutated motor driver, a current detector, a voltage converter, and a controller. The voltage detector detects supply voltage to generate a voltage detection signal. The electronically commutated motor driver is supplied by the supply voltage to generate, according to an electronically commutated signal, an operating current for driving the motor. The current detector detects the operating current to generate a current detection signal. The voltage converter converts the supply voltage into an internal voltage. The controller is supplied by the internal voltage and generates the electronically commutated signal according to a plurality of control parameters. When the controller determines that a specific event has happened according to the control parameters, the controller stops generating the electronically commutated signal and then stores the control parameters.

Provided are embodiments for a system and method for controlling a boost control circuit. Embodiments include a power supply and a boost converter circuit coupled to the power supply, wherein the boost converter circuit is operable to provide power to the load. Embodiments also include a 3-phase inverter coupled to the boost converter, wherein the 3-phase-inverter is operable to provide a 3-phase output, and a controller coupled to the boost converter and the 3-phase inverter. The controller can be configured to receive a voltage level of a power supply and a voltage level of a 3-phase inverter; compare a power threshold to at least one of: the voltage level of the power supply and the voltage level of the 3-phase inverter; and control an operation of the boost converter circuit to operate in a boost mode or a rectification mode based at least in part on the comparison.

A power module for driving a motor includes: a positive bus input voltage terminal; a phase terminal for each motor phase; an inverter including a half bridge for each motor phase, each half bridge including a high-side power switch electrically coupled between the positive bus input voltage terminal and respective phase terminal, and a low-side power switch electrically coupled between the respective phase terminal and ground; a first driver circuit for driving a gate terminal of each power switch; a protection switch electrically coupled in series between the positive bus input voltage terminal and each high-side power switch, and having a greater short-circuit withstand time and a lower short-circuit current level compared to each inverter power switch; and a second driver circuit for turning on the protection switch during normal operation and turning off the protection switch in response to a detected short circuit condition.

A system for braking an electric motor. For each motor winding, a first switch is connected between the winding and electrical ground and in series with a resistor and is closeable to connect the winding to ground through the resistor, and a second switch is connected between the winding and ground and is closeable to bypass the resistor. A controller receives feedback regarding the speed and sends to the second switch a pulse width modulated signal which selectively opens and closes the second switch to connect and disconnect the resistor to achieve an optimal equivalent average stator resistance for the motor speed which results in a power transfer to the resistor and increases a braking torque as the motor slows. The pulse width modulated signal opens the second switch for a longer time when the motor speed is higher and for a shorter time when the motor speed is lower.