摘要
分布式电源可独立运行,也可并网运行,但为了实现分布式电源的高效利用,一般要并网,通过变换器方式是分布式电源接入电网的主要方式之一.本文探讨了并网逆变器的控制技术策略.并网逆变器采用双矢量模型预测直接功率控制在一定程度上改善了在采用单矢量模型预测直接功率控制时输出电压矢量固定、网侧电流畸变率高、无功功率脉动大等问题,但双矢量模型预测直接功率控制在两个矢量均为有效矢量时输出矢量的幅值不可调,且仅对无功功率实现了无差拍控制,有功功率脉动仍较大.针对这些不足,在其基础上提出了一种并网逆变器的三矢量模型预测直接功率控制策略,该控制策略将两个有效电压矢量与一个零电压矢量作用在一个控制周期内,使输出矢量方向与幅值均可调,且采用有功、无功功率无差拍控制的方式来计算矢量作用时间,进一步提高了控制精度.仿真和实验结果表明,相比单矢量、双矢量模型预测直接功率控制,并网逆变器采用三矢量模型预测直接功率控制的电流谐波含量更低,功率脉动较小,鲁棒性更强.
Distributed generation can operate independently or in grid connected. However, in order to realize the efficient utilization of distributed generation, it is generally connected to the grid. Converter is one of the main ways for distributed generation to connect to power grid. This paper discusses the control strategy of grid connected inverter. The dual-vector model predictive direct power control for grid-connected inverter improves the fixed output voltage vector, high grid-side current distortion rate, large reactive power pulsation and other problems of single-vector model predictive direct power control. However, the two-vector model predicts that the amplitude of the output vector cannot be adjusted when the two vectors are both effective, and the active power pulsation is still large when only the reactive power is controlled by the deadbeat control. Aiming at these deficiencies, a three-vector model of grid inverter is proposed to predict the direct power control strategy. The control strategy is two effective voltage vectors and a zero voltage vector in a control cycle to make the output vector direction and amplitude adjustable. The method of active and reactive power no beat control is applied to calculate the vector action time, which further improves the control precision. The simulation and experimental results show that compared with the direct power control predicted by the single vector model and the double-vector model, the direct power control predicted by the three-vector model for the grid-connected inverter has lower current harmonic content, smaller power pulsation and stronger robustness.
作者
何潜
何攻
陈力
帅红
孙越
HE Qian;HE Gong;CHEN Li;SHUAI Hong;SUN Yue(State Grid Chongqing Electric Power Company,Chongqing 400015,China;School of Electrical Engineering,Chongqing University,Chongqing 400044,China)
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第2期192-202,共11页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金项目(52077017)
国网重庆市电力公司重点科技项目(2021渝电科技10#)。
关键词
直接功率控制
并网逆变器
三矢量
无差拍控制
模型预测控制
direct power control
grid-connected inverter
three vectors
no beat control
model predictive control
