MCU (2001) determines whether at least one of double three-phase inverter (2030) or battery (2002) has a failure, or battery (2002) is fully charged, and switches control to be performed in inverter (2030) between all-phase shut off and three-phase short circuit based on a motor rotation speed of double three-phase motor (2050) when MCU (2001) determines that any one of inverter (2030) and battery (2002) has a failure, or battery (2002) is fully charged. Battery (2002) and inverter (2030) can be protected when current is inhibited from flowing from motor (2050) to battery (2002) due to a failure of inverter (2030) or battery (2002).

An electronic control device with short-circuit protection for actuating an electric motor may include a switching device that is connectable to a power source and a power module coupled to the switching device and configured to be coupled to the electric motor for supplying electrical power. The power module contains an inverter and a capacitor connected in parallel. A current-measuring device may be connected to the power module and configured to output a short-circuit fault signal based on the intensity of electric current in the power module. A control unit connected to the current-measuring device may control the switching device, with the control unit configured to isolate the power module from the power source via the switching device upon the short-circuit fault signal. The current-measuring device may measure an electric current flowing through the capacitor and output the short-circuit fault signal based on a direct-current component of the measured current.

A motor control system includes a motor switching assembly comprising a power converter positioned on a converter path, a first relay positioned on the converter path upstream of the power converter, a second relay positioned on a bypass path that is in parallel with the converter path, and a solid-state switching unit positioned upstream from the converter path and the bypass path. The motor control system also includes a control system that controls operation of the motor switching assembly, with the control system programmed to operate the solid-state switching unit in one of a conducting mode, a non-conducting mode, and a ramping mode, so as to selectively control and condition power flow therethrough. The control system is also programmed to control switching of the first and second relays between open and closed positions to selectively route power along the converter path or the bypass path.

A semiconductor module includes a diode bridge circuit, a sensor configured to measure a current value of the diode bridge circuit, a current limiting circuit having an IGBT connected to the diode bridge circuit, and a protection circuit configured to switch ON and OFF the IGBT in accordance with the current value of the diode bridge circuit measured by the sensor.

A method, a device, and a system for protecting parallel-connected topology units are provided. A target signal transmitted via the signal synchronization line is obtained, and the target signal is sent to other controllers based on a type of the target signal. If the target signal is a carrier synchronization signal, the current power module is controlled to perform carrier synchronization and to be in a working mode. If the target signal is a power module fault signal, the current power module is controlled to be in a shutdown mode. The signal synchronization lines between the parallel-connected topology units are shared in a time-sharing manner, where the carrier synchronization signal is transmitted if the power module works normally, and the power module fault signal is transmitted if the power module is faulty. The topology units monitor the transmitted target signal in real time for fast synchronous protection.

According to one aspect, an uninterruptible power supply system is provided including an input configured to receive input power, an interface configured to be coupled to a backup power supply and to receive backup power from the backup power supply, an output configured to provide output power derived from at least one of the input power and the backup power to a load, a power converter coupled to the input, a capacitor, and a shoot-through detector coupled to the capacitor. The shoot-through detector is configured to obtain a first voltage value indicative of a first voltage across the capacitor, obtain a second voltage value indicative of a second voltage across the capacitor, compare the first voltage value to the second voltage value, determine, based on the comparison, that the capacitor is experiencing a shoot-through condition, and provide an output signal indicative of the shoot-through condition.

An apparatus according to an embodiment includes a control circuit to control operations of an inverter and a switch. The control circuit judges whether or not a power system has a power failure, based on values of the system voltage and a frequency of the power system; and calculates a phase difference between a phase of the output voltage of the inverter and a phase of the system voltage and generate, by means of the phase difference, an output frequency pattern for changing a frequency of the output voltage of the inverter. The control circuit, when it is judged that the power system has recovered from the power failure, controls the inverter to change the frequency of the output voltage of the inverter in line with the output frequency pattern, and closes the switch after the phase difference becomes smaller than or equal to a threshold.

In the field of voltage source converters for high voltage direct current (HVDC) power transmission there is provided a protection arrangement for a switching device. The protection arrangement comprises a thyristor that has main current-carrying terminals which in use are connected in reverse parallel with a switching device to be protected, whereby during normal operation of the switching device a reverse voltage is applied to the thyristor. The protection arrangement also includes a trigger circuit that is operatively connected with a gate control terminal of the thyristor. The trigger circuit is configured to apply a voltage to the gate control terminal of the thyristor when the reverse voltage applied to the thyristor reaches a safety threshold voltage whereby the thyristor fails and presents an irreversible short-circuit across the main current-carrying terminals of the switching device.

A method of controlling an electric power assisted steering (EPS) system comprising one or more inverter bridges each connected to a multi-phase motor configured to provide power assist to steering of a vehicle, each inverter comprising a plurality of switching elements each associated with a phase of the motor, is provided. The method comprises, preventing current flow in said one or more affected inverters by applying a gate-source voltage to one or more of the switching elements of the affected inverter bridge(s) in response to detecting a predefined event affecting current flow in one or more of the inverter bridges. A control system for an electric power assisted steering apparatus comprising one or more inverter bridges and a control means configured to control the switching elements in accordance with the method is also provided.

A drive control apparatus and method for a yaw motor of a wind turbine is provided. The drive control apparatus includes a frequency converter, a fault cut-out contactor, and a contactor. The frequency converter is configured to perform drive control on the yaw motor. The fault cut-out contactor is connected in series between the frequency converter and the yaw motor, and configured to be switched off in a case of a fault in the frequency converter, to isolate the failed frequency converter. The contactor is connected in parallel with the frequency converter and the fault cut-out contactor, connected to the yaw motor, and configured to continue to drive the yaw motor in a case that the fault cut-out contactor is switched off. The drive control apparatus and method can solve problem of low reliability of drive control of the yaw motor.