论文部分内容阅读
当电网不对称时，PWM整流器最大运行功率会受到功率器件容量的限制而降低。该文基于瞬时功率理论分析了PWM整流器在电网不对称时的数学模型。介绍了电网不对称时两种整流器的控制策略：平衡的正序电流控制(balanced positive sequence current control，BPSC)和瞬时有功功率控制(instantaneous active power control，IAPC)。采用BPSC策略能够扩展 PWM 整流器最大运行功率，但有功功率波动较大，而IAPC策略能够抑制有功功率波动，但运行功率较小。在此基础上文中提出了一种平衡正序电流和瞬时有功功率的协调控制策略(hybrid balanced positive sequence and instantaneous active power control，HBPSIAPC)，从而实现PWM整流器功率扩展和有功功率波动最小。通过采用标幺值，简化了理论推导和分析过程。最后，在实验室搭建了PWM整流器的实验平台，验证了所提出控制策略的可行性。“,”When the grid voltage dips, the processing power of PWM rectifier reduce due to the current ability of switch device. This paper analyzed the mathematical model of a PWM rectifier under grid voltage dips based on the instantaneous power theory. Two control strategies for the PWM rectifier under grid voltage dips were introduced, one for balanced positive sequence current control (BPSC), and the other for instantaneous active power control (IAPC). The first can suppress the fluctuation on the active power, and the latter can extend the range of processing power of PWM rectifier. A hybrid balanced positive sequence and instantaneous active power control was proposed, which can extend processing power of PWM rectifier but the fluctuation on the active power can be minimized. The analysis in this paper was carried out in the p.u. system, and some simple conclusions were drawn. Corroboration of the expected features of the proposed control strategy was carried out by means of simulations and experiments.