A wireless power transfer system can be achieved at a low cost, can be used as both a power transmission apparatus and a power reception apparatus, and can cope with a change in coupling coefficient of a resonant coil of the power transmission apparatus and a resonant coil of the power reception apparatus. The wireless power transfer system is a power transmission apparatus that is able to perform bidirectional wireless power transmission, and includes the following: a power supply; a switching circuit that includes a plurality of switching devices; a resonator that includes a coil and a capacitor; a drive control circuit that controls an ON/OFF operation of each switching device of the switching circuit; and a detector that detects a resonance current flowing through the switching circuit. The drive control circuit controls the ON/OFF of each switching device of the switching circuit to perform a power transmission operation or a power reception operation based on a resonant current waveform detected by the detector.

A multi-phase power converter includes two or more multi-phase, bi-directional, multi-level, switching power converter subcircuits, connected in parallel at respective AC and DC sides, so as to provide a multi-channel, bi-directional, multi-level configuration. The AC sides of the switching converter subcircuits are directly coupled to one another and to a multi-phase AC input via series interface reactors, and the DC sides of the switching converter subcircuits are directly connected to one another and to a common split-capacitor bank at each level of the multi-level outputs of the switching converter subcircuits. A control circuit is configured to selectively control one or more switching semiconductor devices in each of the switching converter subcircuits. In some embodiments, the control circuit includes a closed-loop zero-sequence controller and a zero-sequence generator configured to eliminate circulating current among the switching converter subcircuits and to balance voltages across levels of the common split-capacitor bank.

A multi-phase power converter includes two or more multi-phase, bi-directional, multi-level, switching power converter subcircuits, connected in parallel at respective AC and DC sides, so as to provide a multi-channel, bi-directional, multi-level configuration. The AC sides of the switching converter subcircuits are directly coupled to one another and to a multi-phase AC input via series interface reactors, and the DC sides of the switching converter subcircuits are directly connected to one another and to a common split-capacitor bank at each level of the multi-level outputs of the switching converter subcircuits. A control circuit is configured to selectively control one or more switching semiconductor devices in each of the switching converter subcircuits. In some embodiments, the control circuit includes a closed-loop zero-sequence controller and a zero-sequence generator configured to eliminate circulating current among the switching converter subcircuits and to balance voltages across levels of the common split-capacitor bank.

A system for controlling a plurality of power converters in a power system so as to turn each of the plurality of power converters into an ON state or an OFF state as a function of a sensed input power and a sensed output power such that one or more of the plurality of power converters in the ON state are operating in an optimal power efficiency range.

A converter system and a method for operating a converter system having block-type energy feedback, in particular, includes: a power inverter that feeds energy back to an AC-voltage supply system, i.e. in particular a first power inverter; a DC/DC transformer having a control unit; and an electric motor, which is able to be fed by a second power inverter. The DC-voltage-side terminal of the second power inverter is connected to a first terminal of the DC/DC transformer 102, and a current-acquisition device for acquiring the current conveyed by the DC/DC transformer to the terminal of the regenerative power inverter on the DC-voltage side is connected to a control unit, e.g., such that the current values acquired by the current-acquisition device are supplied to the control unit. The control unit supplies to the DC/DC transformer control signals such that the voltage supplied by the DC/DC transformer to the regenerative power inverter, the acquired current is able to be controlled, in particular controls, to a setpoint-value characteristic.

A converter system and a method for operating a converter system having block-type energy feedback, in particular, includes: a power inverter that feeds energy back to an AC-voltage supply system, i.e. in particular a first power inverter; a DC/DC transformer having a control unit; and an electric motor, which is able to be fed by a second power inverter. The DC-voltage-side terminal of the second power inverter is connected to a first terminal of the DC/DC transformer 102, and a current-acquisition device for acquiring the current conveyed by the DC/DC transformer to the terminal of the regenerative power inverter on the DC-voltage side is connected to a control unit, e.g., such that the current values acquired by the current-acquisition device are supplied to the control unit. The control unit supplies to the DC/DC transformer control signals such that the voltage supplied by the DC/DC transformer to the regenerative power inverter, the acquired current is able to be controlled, in particular controls, to a setpoint-value characteristic.

An energy storage apparatus includes: a battery system including at least one battery; a power converting unit converting input/output power characteristics of the battery system into alternating current (AC)-direct current (DC) or DC-AC; a conversion control unit controlling an operation of the power converting unit; an initial driving unit converting DC power of the battery system into AC power and supplying the AC power as power for activating the conversion control unit; and a power selecting unit detecting an output voltage of the power converting unit, selecting, based on a level of the output voltage of the power converting unit, any one of AC power output by the initial driving unit and AC power output by the power converting unit, and supplying the selected AC power as operation power of the conversion control unit.

The present invention generally relates to a modular high power bi-directional half bridge buck/boost converter assembly and, in particular, to a system for converting power from one form of current (either AC or DC) to a differing level of voltage, either lower (buck) or higher (boost), to output a wave signal based on pulse wave modulation (PWM) switching control by means of an external digital controller and methods of operation. In particular, an inverter-converter system includes at least one half bridge module including a plurality of circuit components, at least one inductor which is connected to the at least one half bridge module and a power supply, and a controller which is configured to receive and send instructions to the at least one half bridge module for converting an input voltage to an output voltage and dynamically tune switching frequencies based on a load of the inverter-converter system.

The present invention generally relates to a modular high power bi-directional half bridge buck/boost converter assembly and, in particular, to a system for converting power from one form of current (either AC or DC) to a differing level of voltage, either lower (buck) or higher (boost), to output a wave signal based on pulse wave modulation (PWM) switching control by means of an external digital controller and methods of operation. In particular, an inverter-converter system includes at least one half bridge module including a plurality of circuit components, at least one inductor which is connected to the at least one half bridge module and a power supply, and a controller which is configured to receive and send instructions to the at least one half bridge module for converting an input voltage to an output voltage and dynamically tune switching frequencies based on a load of the inverter-converter system.

An energy conversion device is provided. The energy conversion device includes a reversible pulse-width modulation (PWM) rectifier (102) and a motor coil (103). The motor coil (103) includes L sets of winding units, and each set of winding unit is connected with the reversible PWM rectifier (102), where L2 and is a positive integer. At least two sets of heating circuits of a to-be-heated device are formed by an external power supply (100), the reversible PWM rectifier (102), and the winding units in the motor coil (103). The energy conversion device controls the reversible PWM rectifier (102) according to a control signal, so that a current outputted from the external power supply (100) flows through at least two sets of winding units in the motor coil (103) to generate heat.