A power conversion apparatus and a control method for a power conversion apparatus to reduce an amplitude of an output voltage of a converter when a grid is recovered from a fault, to ensure device safety. The power conversion apparatus includes a controller and a converter, and the controller is connected to the converter. The controller is configured to: after the output voltage of the converter is less than a first threshold, when the output voltage of the converter rises to be greater than a second threshold, reduce an active current output by the converter to a first current value, and reduce a reactive current output by the converter to a second current value, where the second threshold is greater than the first threshold.

A power electronic converter for converting electric energy and a method for controlling a power electronic converter are disclosed. The converter includes a plurality of PE switches, and a control system adapted to transmit control information to the PE switches. The control system includes a master controller and a plurality of local controllers controlling the PE switches. The control system further includes one or more slave devices controlled by the master controller. The control system is configured so that the master controller and the one or more slave devices are connected in a ring network topology. Each slave device and one or more of the local controllers are connected in a star network topology.

The present invention provides an adaptively modulated multi-state inverter system, comprising: a split capacitor, four bridge arms and an isolation switch group, on each of the four bridge arms a pair of complementary power switch groups is arranged; the isolation switch group comprises four fuses and six bidirectional thyristors. The output branches of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected in series with a fuse to output a three-phase voltage, and at three-phase output voltage side two shared auxiliary branches are arranged, one auxiliary branch starts from the fourth bridge arm output branch on which a fuse is connected in series and is then connected to the output terminal of the three-phase voltage via three bidirectional thyristors. The other auxiliary branch starts from the DC side feed branch from the midpoint of the split capacitor, and is connected with the output terminal of the three-phase voltage via three bidirectional thyristors respectively. The invention also provides a modulating method of the multi-state inverter system. The use of the adaptive modulating technology enables the multi-state inverter to have the functions of overcurrent protection, isolation of faulty bridge arms and fault-tolerant control on any single and double bridges.

A re-configurable bank of DC-DC converters has many channels, each with a DC-DC converter and a controller that senses the channel's output voltage and current to adjust a duty cycle of switch signals to the DC-DC converter. A serial bus connects to all controllers and writes digital voltage and current control targets into each controller. The controller has Digital-to-Analog Converters (DACs) that convert the targets to analog voltages that are compared to sensed output voltage and current. The comparison results are compared to a sawtooth wave to generate pulses of the switch signals that have a duty cycle adjusted for the target comparisons. In combined mode, a primary channel's controller generates switch signals for secondary channels having outputs shorted to the primary channel. Secondary channels have a mux to select switch signals from the primary controller during combined mode, and from the secondary controller during separated mode.

Control systems for a multi-level diode-clamped inverter and corresponding methods include a processor and a digital logic circuit forming a hybrid controller. The processor identifies sector and region locations based on a sampled reference voltage vector V* and angle θ.sub.e*. The processor then selects predefined switching sequences and pre-calculated turn-on time values based on the identified sector and region locations. The digital logic circuit generates PWM switching signals for driving power transistors of a multi-level diode-clamped inverter based on the turn-on time values and the selected switching sequences. The control system takes care of the existing capacitor voltage balancing issues of multi-level diode-clamped inverters while supplying both active and reactive power to an IT load. Using the control system, one can generate a symmetrical PWM signal that fully covers the linear under-modulation region.

A switching control circuit for controlling a multi-channel switching circuit can include: a logic control circuit that receives an external operation signal, and generates an enable signal, a trigger signal, and an order signal; a reference voltage regulation circuit that receives the enable signal, the trigger signal, the order signal, and a plurality of input voltage signals, and generates an adjustable reference voltage signal, where the reference voltage regulation circuit is also configured to select one of the plurality of input voltage signals based on the order signal; a feedback control circuit that receives the reference voltage signal, the plurality of input voltage signals, and the output voltage signal, and generates a feedback control signal; and a channel selection circuit that receives the order signal and the feedback control signal, and generates switching control signals to control switching operations of the multi-channel switching circuit.

A power supply device includes a power conversion circuit configured to generate an output voltage from an input voltage, and a controller coupled to the power conversion circuit and configured to control the power conversion circuit to generate the output voltage for causing or enhancing coalescence of a multi-phase liquid mixture when the output voltage is applied to the multi-phase liquid mixture. The controller is configured to control generation of the output voltage in accordance with a synchronization signal. The controller is further configured to generate the synchronization signal and transmit the synchronization signal to another power supply device, or receive the synchronization signal from another power supply device.

A method for operating a gate driver system includes measuring a first parameter according to a first priority schedule synchronously to a first edge of a switching signal generated by a gate driver integrated circuit and having a variable duty cycle. The method includes after measuring the first parameter of the gate driver system and prior to a second edge of the switching signal, measuring at least a second parameter of the gate driver system according to a first round-robin schedule synchronously to the first edge of the switching signal.

A DC-DC switching converter includes power switches selectively coupling an output terminal with a first voltage or with a second voltage. A driver stage is coupled with the power switches for driving the power switches. A driver control stage is coupled with the driver stage for controlling the operation of the driver stage. An output current sensing circuit is coupled with the output terminal and with the driver control stage, and is configured to sense a sign of an output current delivered by the DC-DC switching converter at the output terminal and to generate control signals for the driver control stage. The driver control stage controls the operation of the driver stage according to states of the control signals received from the output current sensing circuit, for selectively delaying the activation of the power switches depending on the sensed sign of the output current.

A multiphase switching converter has a plurality of switching circuits coupled in parallel, and a plurality of control circuits configured in a daisy chain. Each control circuit receives a phase input signal, and provides a phase output signal and a switching control signal for controlling a corresponding switching circuit. When a current sense signal is less than a phase shedding threshold, and if a corresponding one of the control circuits is a last one in the daisy chain or if a pulse on the phase input signal lasts within a preset time period, then a corresponding one of the switching circuits stops a power output, and the phase output signal equals the phase input signal.