A Dual Current Feedback Control Method Applied to Bidirectional Grid-Connected Converter

Abstract

The invention discloses a dual-current feedback control method applied to a bidirectional grid-connected converter, specifically as follows: firstly, according to the principle that the power on both sides of the AC and DC of the three-phase AC / DC converter is equal, the DC bus voltage U dc and three-phase AC / DC converter AC side current i L Substituting the mathematical relationship into the droop control equation, the AC side current i of the three-phase AC / DC converter is obtained L Calculate the equation; then add an active damping feedback loop to the control of the bidirectional grid-connected three-phase AC / DC converter to eliminate the resonance effect generated by the LCL filter. The method of the invention optimizes the DC bus voltage control effect by improving the traditional droop control. The grid-connected current feedback active damping method is used to suppress the resonance, reduce the harmonics of the grid-connected current and improve the system robustness. Through the combination of improved droop control and active damping feedback control, two-way control on both AC and DC sides of the grid-connected converter is formed.

Description

Technical field [0001] The present invention belongs to the technical field and grid current control, and particularly relates to a dual bidirectional current feedback applied to a control method of the network switch. Background technique [0002] With the large number of mining of primary energy use, not only Earth's environment has been seriously polluted conventional energy, coal, oil, natural gas, also depleted, and therefore, as many of its alternative renewable clean energy sources such as solar, wind, etc. gained wide pay attention to. Based on this rapid development of distributed generation technologies, provide important support for large power grid. However, since the intermittent renewable energy sources and volatility, there are some challenges of distributed power grid in the direct process. Microgrid is a distributed power supply, energy storage system, the energy conversion means, monitoring and protection devices, small load, etc. made from pooled with electrici...

AI Technical Summary

Problems solved by technology

Compared with L and LC filters, the LCL filter is small in size and has good high-frequency filtering effect, which can reduce the cost in practical applications, but its own high-order characteristics will cause resonance phenomenon, which will increase the grid-connected current at a specific frequency. Harmonic amplitude, affecting the stable operation of the system

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