谐波补偿式Boost PFC变换器控制策略

Control Strategy of Boost PFC Converter Based on Harmonic Compensation

  • 摘要: 针对低压配网的谐波与无功功率补偿问题,对连接在配网中的单相Boost功率因数校正(PFC)变换器进行了研究,提出了一种平均电流模式谐波补偿控制策略,分析了其补偿原理与补偿能力,并根据其补偿特性设计了相应的电流内环补偿器。该控制策略在不改变配电网结构的前提下,只需改变PFC变换器部分控制电路即可实现与配网谐波与无功功率补偿的统一控制。其次,针对复杂电网下的电压同步锁相问题,利用离散差分法代替传统虚拟两相静止坐标系的构造,有效地减小了计算量。研究结果表明,非线性负载电流的谐波、基波无功分量与Boost PFC变换器自身功率共同影响了该变换器的补偿能力,且非线性负载谐波与无功功率同时补偿时,补偿效果最佳。最后,仿真与实验验证了该控制策略的可行性与理论分析的准确性。

     

    Abstract: Aiming at the problem of harmonic and reactive power compensation in low-voltage distribution networks, a power factor correction (PFC) single-phase converter connected in distribution networks is studied, and an average current mode harmonic compensation control strategy is proposed. The principle and capability of compensation are analyzed and the inner current loop compensator is designed according to its compensation characteristics. Without changing the structure of the distribution network, the control strategy only needs to change part of the control circuit of the PFC converter to realize the unified control with the distribution network harmonic and reactive power compensation. Secondly, the discrete difference method is used to replace the traditional virtual two-phase static coordinate system to reduce the computation cost. The research results show that the harmonic and fundamental reactive components of nonlinear load current and the power of boost PFC converter affect the compensation ability of the converter, and the compensation effect is the best when nonlinear load harmonic and reactive power are compensated simultaneously. Finally, the simulation and experiment verify the feasibility of the control strategy and the accuracy of the theoretical analysis.

     

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