Compensation method for three-phase unbalanced power inverter compensation device in microgrid

Abstract

The invention relates to a compensation method of a micro-grid three-phase imbalance power inversion compensation device. The device comprises a new energy power generation device, a power conversion circuit, filter circuits, interphase relays, grid-connected relays and a controller, wherein the controller controls switching-on and switching-off of eight IBGTs in the power conversion circuit, so that direct current generated by the new energy power generation device is inverted into alternating current which is connected into a power grid through the filter circuits and the grid-connected relays. The compensation method includes the following steps: the controller collects three-phase network voltage effective values, frequency and phases in real time, finds out the phase with the lowest network voltage, calculates voltage differences of the phase and other phases, and adjusts three-phase grid-connected power accordingly. When grid-connected current of the phase with the lowest network voltage reaches a rated value of the power conversion circuit, and voltage of the phase is lower, the grid-connected relays of the other phases are switched off, output current of the other phases are set to be in the same phase as the phase, the interphase relays between the other phases and the phase are switched on, and two phases or three phases are connected to the phase, thereby jointly compensating power and voltage of the phase.

Description

technical field [0001] The invention belongs to a compensation method for a micro-grid power inverter compensation device, in particular to a new energy generation micro-grid three-phase unbalanced power inverter with three-phase grid-connected inverter, inter-phase unbalanced power and voltage compensation, and power factor compensation. The compensation method of the compensation device. Background technique [0002] Energy issues have always been an important factor restricting the development of a human society. Every major progress in society is inseparable from the improvement and replacement of energy. In June 2012, the famous American economist Jeremy Rifkin proposed that the world is about to enter the "post-carbon" era, and the third industrial revolution characterized by the combination of Internet technology and renewable energy will be the The hope for sustainable development and avoiding catastrophic climate change. my country is strategically adjusting the c...

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Problems solved by technology

[0004] The AC three-phase voltage and power output by traditional inverters are balanced, but in distributed power generation systems such as sea islands, many power loads are single-phase, and are distributed unbalanced in the three phases A, B, and C, making The three-phase power imbalance of the microgrid leads to unbalanced three-phase voltage and low voltage of a certain phase, which reduces the quality of power supply and even affects the normal power supply

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