基于级联STATCOM的CPS-SPWM脉冲相移技术

载波移相SPWM(CPS-SPWM)技术作为级联H桥静止无功补偿器(STATCOM)最常用的调制方法,对级联H桥STATCOM输出电压精度、实时性等性能有着重要的影响。通过分析对比CPS-SPWM技术的三种脉冲生成方法—自然采样法、对称规则采样法以及不对称规则采样法,提出基于不对称规则采样的CPS-SPWM脉冲相移技术,以解决传统CPS-SPWM技术在级联H桥数较多时DSP控制复杂、FPGA硬件资源不足等问题。与传统CPS-SPWM技术的仿真对比表明,当级联H桥数目较多时,所设计方法能够在保证STATCOM输出特性的基础上,有效减少硬件资源,简化了电路设计,更便于工程应用。

Pulse phase shifting technology of CPS-SPWM for cascaded STATCOM

As the core modulation technology of cascaded H-bridge static synchronous compensator (STATCOM), carrier phase-shifted SPWM (CPS-SPWM) technique is important for STATCOM output voltage precision and the real-time performance. The three pulse generating methods for CPS-SPWM technique, i.e. natural sampling method, symmetry rule sampling method and asymmetry rule sampling method, are analyzed and compared. Then, CPS-SPWM pulse phase shifting technology based on the asymmetry rule sampling is proposed to solve the problem of DSP control complexity, lack of hardware resources CPLD when the number of cascade H-bridge is large. The simulation results show that compared with traditional CPS-SPWM technology, the proposed method can ensure output characteristics of STATCOM and effectively reduce the hardware resources, which can simplify the circuit design and be easier for the engineering applications.