LCL-type single-phase grid-connected inverter power control and active damping optimization method

Abstract

The invention discloses an LCL-type single-phase grid-connected inverter power control and active damping optimization method. An equivalent synchronous coordinate PI controller is adopted, a two-phase virtual orthogonal system is constructed by adopting an all-pass filter, the problem that data used in previous construction methods have asynchrony or noise interference is introduced is solved, regulation of grid-connected currents at fundamental frequency in a zero steady state error is achieved, and the stability of the system is improved. According to the LCL-type single-phase grid-connected inverter power control and active damping optimization method, the primary differential and the high-frequency components of the grid-connected currents are fed back in real time, the damping of the system is increased, the resonance peak of the LCL filter is restrained, an optimized parameter selection method is given, single-current feedback factors are reduced to a variable, the defect that parameters are difficult to select in single current high-frequency component feedback is overcome, and the reliability and the dynamic nature of the system are improved.

Description

technical field [0001] The invention relates to the field of PWM inverter control and new energy sources thereof, in particular to an LCL type single-phase grid-connected inverter power control and active damping optimization method. Background technique [0002] The shortage of fossil energy and the resulting environmental pollution make photovoltaic power generation one of the research hotspots. At the end of the power grid, a large number of non-resistive loads will generate reactive current, which requires distributed photovoltaic grid-connected systems to provide low harmonics. Distorted active current also needs to provide reactive current to the load. Corresponding research has been carried out on photovoltaic grid-connected control strategies with reactive power compensation functions at home and abroad. The PI adjustment of active power and reactive power in the synchronous rotating coordinate system can be equivalent to proportional resonance control of paired grid...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide an LCL type single-phase grid-connected inverter power control and active damping optimization method to solve the problem of large delay or introduction of traditional single-phase reactive power detection. At the same time, it solves the problem that the current single-phase LCL type grid-connected inverter needs additional sensors or the introduction of single current feedback parameters is difficult to select

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