A series multiplex inverter includes a power conversion unit, a phase difference selection unit, a drive signal generation unit, and a drive signal output unit. The phase difference selection unit selects, from among a plurality of phase difference candidates, the phase difference between rectangular wave voltages from a plurality of single-phase inverters. The drive signal generation unit generates a plurality of drive signals that causes the different single-phase inverters to output a plurality of rectangular wave voltages sequentially out of phase by the phase difference selected by the phase difference selection unit. The drive signal output unit outputs the plurality of drive signals generated by the drive signal generation unit to the plurality of single-phase inverters.

A series multiplex inverter includes a power conversion unit, a phase difference selection unit, a drive signal generation unit, and a drive signal output unit. The phase difference selection unit selects, from among a plurality of phase difference candidates, the phase difference between rectangular wave voltages from a plurality of single-phase inverters. The drive signal generation unit generates a plurality of drive signals that causes the different single-phase inverters to output a plurality of rectangular wave voltages sequentially out of phase by the phase difference selected by the phase difference selection unit. The drive signal output unit outputs the plurality of drive signals generated by the drive signal generation unit to the plurality of single-phase inverters.

A voltage source converter as well as a method and computer program product for controlling the converter. The converter includes at least one phase leg connected between a first DC terminal having a first voltage and a second DC terminal having a second voltage, the phase leg including an upper arm and a lower arm with cells, where a junction between the arms is connected to a corresponding AC terminal. The converter also includes a control unit configured to control the cells to output a train of pulses of trapezoidal shape where the generation of a first control signal for a first cell used to initiate a transition between two levels of a pulse coincides with the decision that a transition is to be made.

A voltage source converter as well as a method and computer program product for controlling the converter. The converter includes at least one phase leg connected between a first DC terminal having a first voltage and a second DC terminal having a second voltage, the phase leg including an upper arm and a lower arm with cells, where a junction between the arms is connected to a corresponding AC terminal. The converter also includes a control unit configured to control the cells to output a train of pulses of trapezoidal shape where the generation of a first control signal for a first cell used to initiate a transition between two levels of a pulse coincides with the decision that a transition is to be made.

The invention relates to a conversion system (100) with a DC side and an AC side, and to an associated control method. The system (100) comprises a primary conversion block (1), a secondary conversion block (2) and a transformer block (3) with at least one primary winding (3.1) connected to the primary conversion block (1) and a secondary winding (3.2R, 3.2S, 3.2T) for each phase (R, S, T) which are connected to the secondary conversion block (2). Each conversion block (1, 2) comprises a plurality of controllable switches, and the system (100) comprises a controller (4) communicated with said switches and configured for causing the opening and closing of said switches in a controlled and coordinated manner.

A new class of DC-AC inverter consists of a buck or two buck converters and two or four low frequency switches, and it achieves ultra-high efficiency, reactive power flow capability, small size and low cost in grid-connected applications.

An inverter system is provided that includes switches that alternate between closed and open states to conduct or block conduction, respectively, of electric current through the switches and switch controllers that control operation of the switches between the closed and open states. In a first operating mode, the controllers control operation of the switches to convert direct current into a single, common phase of an alternating current from a same phase output from each of the switches to power a higher-demand load of a powered system with the single phase of the alternating current. In a second operating mode, the controllers control operation of the switches to convert the direct current into multiple, different phases of the alternating current to power a lower-demand load of the powered system with the multiple, different phases of the alternating current. Each of the switches outputs a different phase of the multiple phases.

An inverter system is provided that includes switches that alternate between closed and open states to conduct or block conduction, respectively, of electric current through the switches and switch controllers that control operation of the switches between the closed and open states. In a first operating mode, the controllers control operation of the switches to convert direct current into a single, common phase of an alternating current from a same phase output from each of the switches to power a higher-demand load of a powered system with the single phase of the alternating current. In a second operating mode, the controllers control operation of the switches to convert the direct current into multiple, different phases of the alternating current to power a lower-demand load of the powered system with the multiple, different phases of the alternating current. Each of the switches outputs a different phase of the multiple phases.

A control unit repeats the series of processing of comparing a first phase representing a phase of the first reference sine wave and being a phase included in the first synchronization signal, with a second phase that is the phase of the second reference sine wave when the first synchronization signal is received when the communication unit receives the first synchronization signal from the other inverter generator, changing a phase change amount per unit time of the second reference sine wave in accordance with the comparison result, continuing to update the phase of the second reference sine wave so that the phase of the second reference sine wave changes with a phase change amount per unit time after the change with reference to the first phase until the next first synchronizing signal is received from the other inverter generator. The control unit compares a third phase that is a phase included in the first synchronization signal received prior to the polarity reversal timing of the second reference sine wave by the communication unit and that is one of the first phases, with a fourth phase that is a phase of the second reference sine wave when the first synchronizing signal is received, changing the phase change amount per unit time of the second reference sine wave in accordance with the comparison result, and predicts the polarity inversion timing of the first reference sine wave by continuing updating the phase of the second reference sine wave so that the phase of the second reference sine wave changes with a phase change amount per unit time after the change.

An inverter system is provided that includes switches that alternate between closed and open states to conduct or block conduction, respectively, of electric current through the switches and switch controllers that control operation of the switches between the closed and open states. In a first operating mode, the controllers control operation of the switches to convert direct current into a single, common phase of an alternating current from a same phase output from each of the switches to power a higher-demand load of a powered system with the single phase of the alternating current. In a second operating mode, the controllers control operation of the switches to convert the direct current into multiple, different phases of the alternating current to power a lower-demand load of the powered system with the multiple, different phases of the alternating current. Each of the switches outputs a different phase of the multiple phases.