Parallel APF DC side voltage control method based on sliding mode PI compound control algorithm

Abstract

The invention discloses a parallel APF DC side voltage control method based on a sliding mode PI compound control algorithm. The method comprises the following steps: firstly establishing a low-order system model of a dq coordinate system by using synchronous rotating coordinate transformation; determining the sliding mode switching function of the DC side voltage according to the selection principle of sliding mode surfaces; and finally designing the control parameter output function of a PI controller according to the switching function of the sliding mode surfaces. By adopting the control method disclosed by the invention, the steady state performance and response speed of the DC side voltage can be improved, and the voltage fluctuation can also be effectively reduced; and a parallel APF control system based on the sliding mode PI compound control algorithm has good robust performance and dynamic performance. According to the parallel APF DC side voltage control method based on the sliding mode PI compound control algorithm disclosed by the invention, the parameter of the PI controller is determined through the sliding mode controller, the steady state accuracy and response speed during load sudden change and reference voltage jump can be increased, the power loss at the DC side can be reduced, and thus the compensation ability of the parallel APF (active power filter) can be ensured.

Description

technical field [0001] The invention belongs to the field of active filter control, in particular to a parallel APF DC side voltage control method based on a sliding mode PI composite control algorithm. Background technique [0002] Parallel active power filter (Active Power Filter, APF) is an effective means to solve the harmonic pollution of the power grid. It can realize accurate, real-time and effective compensation for the harmonics, negative sequence current and reactive power existing in the power grid system. The output compensation characteristics of the active filter mainly depend on the control method of the current and voltage, and the main circuit topology of the converter device used. At present, the research on the topology of active power filters is relatively mature, and most of them adopt the structure of traditional three-phase PWM converters. Therefore, the improvement of the compensation performance of parallel active power filters mainly depends on the ...

AI Technical Summary

Problems solved by technology

When the traditional PI controller is used for DC side voltage control, although it can finally meet the DC voltage stability, the response speed of the voltage is slow, and there is overshoot, which cannot meet the needs when the load changes suddenly and the reference voltage jumps.

The fuzzy controller does not depend on the system, it is easy to transplant, and its robust performance is strong; however, its control accuracy is poor, and the large fluctuation of the DC side voltage leads to an increase in loss and reduces the compensation performance of the APF

The implementation of the voltage-based adaptive control method is relatively complicated, and it takes up more resources on the chip when the control algorithm is operated, and the dynamic performance of the DC side voltage is not ideal.

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