A converter system includes a rectifier, a DC link stage and an inverter connected in series. A control unit includes a slow reference frame angle determination unit that generates a slow reference frame angle θ.sub.r,slow representing an angle that is slowly following a grid phase deviation, and a fast Phase Locked Loop generating a fast reference frame angle θ.sub.r,fast representing an angle that is fast following a grid phase deviation. The control unit uses the slow reference frame angle θ.sub.r,slow and the fast reference frame angle θ.sub.r,fast to control the rectifier output current, and the fast reference frame angle θ.sub.r,fast to control the inverter output voltage and to synchronize the inverter output voltage with the grid voltage.

A permanent magnet synchronous generator control system includes a charging circuit connected between a vehicle generator winding and a battery, a controller connected with the charging circuit, and a current detection circuit for detecting a magnitude of charging current and a voltage feedback circuit for detecting a magnitude of charging voltage that are connected with the controller. The charging circuit includes a chopper circuit for chopping an AC voltage output by the vehicle generator winding and a rectifier circuit for rectifying the chopped AC voltage into a DC voltage for charging the battery. The controller is configured to control the charging circuit to adjust the magnitude of charging current or voltage based on the detection result from the current detection circuit or voltage feedback circuit, so as to maintain the stability of the charging voltage for the battery and obtain a constant power output.

A power conversion device includes a power conversion circuit, a memory, a voltage detection circuit, a current detection circuit, and a control circuit. The power conversion circuit controls a switching device based on a switching pulse signal to convert direct current power into alternating current power and output the alternating current power to a power supply target. The memory stores an alternating current phase difference. The voltage detection circuit detects an alternating current voltage effective value. The current detection circuit detects an alternating current effective value. Based on the alternating current phase difference, the alternating current voltage effective value, and the alternating current effective value, the control circuit stops output of the switching pulse signal at a time when an alternating current has a value of 0.

A permanent magnet synchronous generator control system includes a charging circuit connected between a vehicle generator winding and a battery, a controller connected with the charging circuit, and a current detection circuit for detecting a magnitude of charging current and a voltage feedback circuit for detecting a magnitude of charging voltage that are connected with the controller. The charging circuit includes a chopper circuit for chopping an AC voltage output by the vehicle generator winding and a rectifier circuit for rectifying the chopped AC voltage into a DC voltage for charging the battery. The controller is configured to control the charging circuit to adjust the magnitude of charging current or voltage based on the detection result from the current detection circuit or voltage feedback circuit, so as to maintain the stability of the charging voltage for the battery and obtain a constant power output.

In the field of gate drivers there is provided a regulated voltage source (10; 10A, 10B), for a gate driver (200; 300) of a switching device (18) having a gate terminal (26) via which the switching device (18) can at least be turned on. The regulated voltage source (10; 10A, 10B) comprises an input terminal (12) via which the regulated voltage source (10; 10A, 10B) in use receives current. The regulated voltage source (10; 10A, 10B) also includes first and second connection terminals (22, 24) via at least one of which the regulated voltage source (10; 10A, 10B) in use applies a voltage (V) to a gate terminal (26) of a switching device (18). In addition the regulated voltage source (10; 10A, 10B) includes a regulated energy storage stage (28) which is electrically connected between the input and output terminals (12, 22, 24) and which includes a primary energy storage device (30; 30A, 30B) connected in parallel with a storage limiter (34) to limit the amount of energy stored in the primary energy storage device (30; 30A, 30B). Between the primary energy storage device (30; 30A, 30B) and the storage limiter (34) lies an energy retainer (46) to prevent the escape of energy from the primary energy storage device (30; 30A, 30B) via the storage limiter (34). The regulated voltage source (10; 10A, 10B) further includes a freewheel diode (50) that is arranged in parallel with the energy storage stage (28) and a secondary energy storage device (52; 52A, 52B) which is arranged in parallel with each of the freewheel diode (50) and the energy storage stage (28).

A power conversion device includes a power conversion circuit, a memory, a voltage detection circuit, a current detection circuit, and a control circuit. The power conversion circuit controls a switching device based on a switching pulse signal to convert direct current power into alternating current power and output the alternating current power to a power supply target. The memory stores an alternating current phase difference. The voltage detection circuit detects an alternating current voltage effective value. The current detection circuit detects an alternating current effective value. Based on the alternating current phase difference, the alternating current voltage effective value, and the alternating current effective value, the control circuit stops output of the switching pulse signal at a time when an alternating current has a value of 0.