Altenergy Power System, Inc.

Yongchun Yang

Yuhao Luo

Biaojie Qi

Jian Wu

A three-phase inverter and a control method therefor are provided. Resonant capacitors are provided between the midpoints of three bridge arms and the positive and negative poles of a DC bus to constitute resonant units with output inductors, so as to establish a resonant network for the implementation of soft switching, without adding a switching transistor. Compared with the soft-switching of the three-phase inverter in the conventional technology, circuit devices are saved, the control process is simplified, and system hardware and software overheads are reduced. By controlling the three-phase inverter to operate in a continuous mode, the switching loss of the switching transistor and the conduction loss of a flyback diode in the switching transistor are reduced, the conversion efficiency is improved, the electromagnetic noise caused by the switching transistor is reduced, and high-quality grid currents are output.

Three-phase inverter and control method for same

A three-phase grid-connected inverter, a control system thereof and a control method therefor. The inverter is a three-phase three-leg grid-connected inverter, and a filter capacitor is connected to a negative electrode of a DC input bus to form a filter loop, so as to filter harmonic wave in the circuit, realizing high-quality grid-connected current at small power, without increasing an inductance value, so that the parallel inverter device in the system operates stably and thus is applicable to photovoltaic microinverters. Moreover, the three-phase three-leg grid-connected inverter operates in a discontinuous conduction mode, that is, in a switching cycle, the inductive current is reduced to 0, so that the switching loss of the three-phase three-leg grid-connected inverter is reduced.

Control method and system for three-phase grid-connected inverter, and three-phase grid-connected inverter

A three-phase grid-connected inverter, and a method and a device for controlling the three-phase grid-connected inverter are provided. The method is applied to a three-phase three-leg grid-connected inverter. A structure of the three-phase three-leg grid-connected inverter is improved, so that a filter capacitor (C, C, and C) is connected to a negative electrode of a direct current input bus to form a harmonic bypass circuit. Inverter devices connected in parallel in the system operate stably without increase of inductance of an inductor (L, L, L). In addition, the three-phase three-leg grid-connected inverter according to the present disclosure operates in a discontinuous mode of inductor current (i, i, and i). That is, in the process that a power switch transistor (Q, Q, Q, Q, Qand Q) on bridge legs is turned on, the inductor current (i, i, and i) drops to zero.

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Zhejiang, China

Yongchun Yang