清洁能源发电并网逆变器有限状态模型预测控制

摘要

In order to reduce the switching frequency and avoid delay problems caused by the algorithm execution,a model predictive coordinated control(MPCC)strategy is designed.When sampling frequency is high,the delay problem of MPDPC algorithm implementation will influence the output power quality and increase output power ripple.Based on direct power prediction model,a two-step power prediction was designed to compensate time delay.In order to realize coordinated control,an optimized cost function was designed by adding target additions and analyzing the influence of the cost function on the control quality. The 5 kW experimental prototype of grid connected inverter was designed.The comparisons of the experi-mental results show that the MPCC strategy can decrease power ripple and reduce switching frequency, which validates the effectiveness of the proposed plan.%针对清洁能源发电并网逆变器执行模型预测直接功率控制算法产生的延时问题,通过深入研究有限状态模型预测直接功率控制方法,设计模型预测协调控制策略,有效降低开关频率,实时更新功率器件开关状态,减小算法时滞.首先,在直接功率预测模型基础上,对输出功率进行两步预测,实现延时补偿.其次,分析价值函数对控制品质的影响机理,通过增加开关次数附加项,设计优化的价值函数,实现并网逆变器的协调控制.为验证控制系统性能,设计5 kW实验平台.对比不同控制策略下的实验结果表明,所设计控制策略能够减小输出功率波动,降低开关频率,灵活调节输出功率.实验结果验证了所提出控制策略的有效性.