A circuit for three-phase detection, a method for three-phase detection and a compressor are provided. The circuit for three-phase detection includes a first optical coupler and a second optical coupler. A first input end and a second input end of the first optical coupler are respectively connected to a first phase wire and a third phase wire of a power supply assembly, and a first output end of the first optical coupler provides a first output signal. A first input end and a second input end of the second optical coupler are respectively connected to a second phase wire and the third phase wire of the power supply assembly, and a first output end of the second optical coupler provides a second output signal. The first output signal and the second output signal are used to indicate a phase state of a three-phase alternating current of the power supply assembly.

The method according to the invention enables the diagnosis (15, 16) of phase current sensor defects in a system for controlling a synchronous rotary electrical machine of a motor vehicle. According to the invention, the method takes into account the differences (îd, lq) between measurements provided (14) by the sensors, and nominal values of the phase currents (ia, ib, ic) in order to diagnose defects. The differences are calculated (18) in a rotating Park reference frame (17) and are separate from an electromechanical model of the machine. The method detects sensor defects if the differences are substantially non-zero (19) and an offset sensor defect if a residual pulsation (ω res) of the differences is substantially equal to a measured speed (w) of the control system.

A method for testing the operation of an actuating circuit of a DC motor is disclosed, wherein electrical voltage connections of the DC motor are connected to a voltage source via the actuating circuit. An operating switch is arranged between the actuating circuit and the voltage source for starting up the DC motor via the actuating circuit. When the operating switch is switched on, the actuating circuit is initialized. Initialization prompts the potential on a voltage connection of the DC motor to be checked, and an indicator is actuated if, during the check, a potential on the voltage connection of the DC motor is determined that is above a prescribed limit value.

This power conversion device has: a current measurement unit for measuring phase current; a current vector calculation unit for calculating a current vector by performing 3-phase to 2-phase conversion on the phase current; an amount-to-be-analyzed calculation unit for calculating, on the basis of the current vector, an amount to be analyzed; and a feature amount waveform extraction unit for extracting a waveform in a specific frequency range on the basis of the amount to be analyzed.

Disclosed herein is an electric motor control circuit, a printing device, and a method of overvoltage protection for an electric motor. The electric motor control circuit comprises a controller, a voltage converter to generate a supply voltage of the controller from a voltage at terminals of the electric motor and a switchable braking circuit connected to the motor terminals. The controller is to activate the braking circuit if the voltage at the motor terminals exceeds a threshold voltage while the controller is in an off-state.

An apparatus according to the aspect of the embodiments includes a phase determiner configured to determine a rotational phase of a rotor, a speed determiner configured to determine a rotational speed of the rotor, a controller having a first control mode for controlling the motor by supplying constant currents to windings, and a discriminator configured to discriminate whether a rotation of the motor is abnormal based on the rotational speed when the rotational speed corresponding to a command speed is equal to or higher than a predetermined value in a state where the controller is controlling the motor in the first control mode. When a signal output from the discriminator indicates that the rotation of the motor is abnormal, the controller stops the motor. When the signal output from the discriminator indicates that the rotation is not abnormal, the controller continues a drive of the motor.

Described is a method including monitoring a point of regulation voltage input to a generator control unit and monitoring a generator output voltage as a backup point of regulation voltage input. The method also includes detecting an overvoltage fault at the point of regulation voltage input, the backup point of regulation voltage input, or both. Additionally, the method includes opening a first solid-state switch (110) in response to detecting the overvoltage fault. Opening the first solid-state switch (110) prevents provision of an input signal (104) to a generator excitation field (102). Further, the method includes opening a generator excitation field relay (112) in response to detecting the overvoltage fault. Opening the excitation field relay (112) also prevents provision of the input signal (104) to the generator excitation field (102).

Systems and methods for estimating electrical component degradation include a processor programmed to: compute a cumulative degradation value for an electrical system component of an electrical system based on an operating parameter of the electrical system component; and to compute a corrosion compensated cumulative degradation value for the electrical system component based on the cumulative degradation value and a corrosion rating of the electrical system.

The present invention discloses a vehicle. The vehicle includes an AC electric machine configured to generate traction driving force, a DC bus configured to provide a DC voltage, an inverter, and a controller. The inverter is coupled with the DC bus and configured to convert the DC voltage from the DC bus to an AC voltage to drive the AC electric machine, and the inverter includes a plurality of transistors. The controller is configured to control the inverter to maintain the vehicle to run in a fault-tolerant mode when an open circuit fault occurs in one of the transistors in the inverter during running of the vehicle. The present invention further discloses a control method of the vehicle and a system.

An embodiment driver circuit comprises a power supply pin configured to receive a power supply voltage, and a set of control pins configured to provide a set of control signals for controlling switching of a set of switches of an h-bridge circuit comprising a pair of high-side switches and a pair of low-side switches. The driver circuit comprises control circuitry coupled to the control pins and configured to generate the control signals, and sensing circuitry coupled to the power supply pin and configured to generate a detection signal indicative of the power supply voltage exceeding a threshold value. The control circuitry is sensitive to the detection signal and is configured to generate the control signals to activate one of the pair of high-side switches and the pair of low-side switches and de-activate the other of the pair of high-side switches and the pair of low-side switches.