A system and method for mitigating overvoltage on a DC link of a power converter of an electrical power system connected to a power grid includes receiving a voltage feedback signal from the DC link for a predetermined time period. The method also includes determining a rate of change of the voltage feedback signal during the predetermined time period. Further, the method includes predicting a future voltage value on the DC link as a function of the voltage feedback signal and the rate of change of the voltage feedback signal. Moreover, the method includes controlling the electrical power system based on the future voltage value.

An energy conversion system includes a low-impedance generator having at least one armature winding set. The armature winding set includes a plurality of single-phase coils. The system also includes a current source converter assembly electrically coupled to an armature of the generator. The current source converter assembly includes at least one current source converter that includes a current source rectifier coupled to a current source inverter via a DC link and at least one capacitor across the plurality of single-phase armature coils. The capacitor(s) of the current source converter(s) is configured to absorb high frequency components of current pulses generated by the current source converter so as to minimize current ripple in a current applied to the plurality of single-phase coils.

An electric working machine in one aspect of the present disclosure includes a main current-path, a driving unit including a motor and at least one first semiconductor-switching-element, a controller, a bypass current-path, a second semiconductor-switching-element, and a switch driver. The main current-path is arranged between a positive electrode and a negative electrode of a battery. The driving unit is situated in the main current path. The bypass current-path is arranged in parallel with the driving unit. The second semiconductor-switching-element is situated in the bypass current-path. The switch driver causes the second semiconductor-switching-element to interrupt the bypass current-path in an event that a voltage value of a drive voltage applied to the driving unit is less than a threshold value, and causes the second semiconductor-switching-element to complete the bypass current-path in an event that the voltage value is equal to or greater than the threshold value.

A control device for an electric power conversion apparatus, the control device detecting occurrence of an earth fault in a direct-current path in a system in which the direct-current path between a solar cell module and an electric power conversion apparatus is grounded, is provided. The control device for the electric power conversion apparatus includes: a grounding control unit configured to, in a system in which a direct-current path between a solar cell module and an electric power conversion apparatus is grounded via a switch, control a switch; and an earth fault determination unit configured to, when the switch is open under the controlled of the grounding control unit, detect whether or not an earth fault has occurred in the direct-current path.

A switching circuit for controlling charging input from a DC source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery, the switching circuit is provided with a switching device which when positioned in series with the inverter circuit and the DC source, the switching device configured to control the charging input provided to the at least one respective battery, the switching device controllable in conjunction with switches in the at least one inverter circuit based on at least one voltage of the at least one respective battery.

Power converters, protection systems and methods to protect a precharge circuit in which a precharge resistor voltage is indirectly monitored during a normal operating mode, and a rectifier and an inverter are selectively disabled in response to the indirectly measured precharge resistor voltage indicating a fault in a precharge circuit SCR.

An energy conversion system includes a low-impedance generator having at least one armature winding set. The armature winding set includes a plurality of single-phase coils. The system also includes a current source converter assembly electrically coupled to an armature of the generator. The current source converter assembly includes at least one current source converter that includes a current source rectifier coupled to a current source inverter via a DC link and at least one capacitor across the plurality of single-phase armature coils. The capacitor(s) of the current source converter(s) is configured to absorb high frequency components of current pulses generated by the current source converter so as to minimize current ripple in a current applied to the plurality of single-phase coils.

Systems and methods for gate driver with field-adjustable undervoltage lockout (UVLO) are disclosed. A gate driver system comprises a control circuit and a driver circuit. The driver circuit incorporates a field-adjustable UVLO, a control logic, and an inverter. The level of the field-adjustable UVLO is adjustable by an external circuit, which can be a resistor based voltage divider. By setting the UVLO level externally adjustable and by moving a reference ground to the external voltage divider, the gate driver system is able to implement gate control for various load without needing extra ground pin.

A communication system for use in a switching module includes a low-side control block coupled to control switching of a low-side switch of the switching module. The low-side control block is further coupled to be referenced with a low-side reference system ground. A high-side control block is coupled to control switching of a high-side switch of the switching module. The high-side control block is further coupled to be referenced with a floating node of the switching module. During steady state operation, the low-side control block is coupled to send signals during each switching cycle to the high-side control block to turn the high-side switch on and off. A status update is communicated from the high-side control block to the low-side control block through a first single-wire communication link.

Provided is a power conversion device with which it is possible to acquire a sign of a system stop before the system stops, and to minimize the nonworking time of the system. A power conversion device for converting DC voltage or AC voltage into AC voltage, the power conversion device being characterized by having an abnormality detection unit for detecting abnormalities in the power conversion device, a restart unit for stopping the power conversion device and automatically performing a restart when the abnormality detection unit has detected an abnormality, a restart recording unit for recording restart information of when the restart unit has restarted, and a sign diagnostic unit for inputting the restart information recorded by the restart recording unit and performing a sign diagnosis of the abnormality in the power conversion device on the basis of the restart information, the sign diagnostic unit performing the sign diagnosis on the basis of the number of restarts and outputting a sign diagnostic result.