基于Boost升压的变频器低电压穿越应用

Application of Low Voltage Ride Through of Inverter Based on Boost

传统比例积分(PI)控制策略在升压较大时存在输出电压振荡的现象,分析该现象发生的原因,探讨了火电厂低电压穿越装置具备过零开通的单排高频直流斩波Boost升压拓扑实现方法及工作状态,提出一种新的基于经验值延迟电流微分补偿控制策略。在PSCAD/EMTDC系统环境下搭建了硬件拓扑和控制电路的仿真模型,验证了算法的收敛性和有效性,并采集现场试验数据,对比分析了传统PI控制策略和所提方法在电压跌落至90%,60%,20%时运行性能。结果表明,所提方法能解决传统PI控制策略中存在的输出电压振荡、启动时间长等问题,研究成果大量应用于火电厂实际生产中。

Aiming at the phenomenon that the output voltage oscillates in the traditional proportional integral(PI)control strategy when the boost is relatively large,the reason for this phenomenon is analyzed,and the method and working status of a single-row high-frequency DC chopper-boost topology with zero-crossing turn-on for low voltage ride through devices in thermal power plants are discussed,and a new delay current differential compensation control strategy based on experience values is proposed.In the PSCAD/EMTDC system environment,a simulation model of hardware topology and control circuit is built to verify the convergence and effectiveness of the algorithm,and field test data is collected.The running performance of the traditional PI control strategy and the method proposed are compared and analyzed when the voltage drops to 90%,60%and 20%.The results show that the method proposed can solve the problems of output voltage oscillation and long start-up time in the traditional PI control strategy.The research results are widely used in the actual production of thermal power plants.