降低电压不平衡度的三相并网逆变器阻尼控制策略

针对低压配电网中单、三相负载并存，导致三相电压失衡，提出三相并网逆变器降低电压不平衡度的阻尼控制策略。基于序分量法建立逆变器功率阻尼控制策略的数学模型，分析其电压不平衡抑制机理，阐明正序控制策略功率输出和阻尼控制策略降低电压不平衡度之间存在弱耦合关系，并在此基础上又进一步提出改进阻尼控制策略，简化了控制难度。对10节点不对称网络进行仿真分析，结果验证文章所提的控制策略能够实现逆变器向外输出有功功率和无功功率的同时，还能降低网络的电压不平衡度。

Damping Control Strategy for Three-Phase Grid-Connected Inverter to Reduce Voltage Imbalance

Single-phase and three-phase load coexist in low-voltage distribution network, which cause imbalance of three-phase voltages. This paper presents a damping control strategy for three-phase inverter to reduce voltage imbalance factor. On the basis of sequence component method, a mathematical model of power damping control strategy is established and the voltage imbalance suppression mechanism is analyzed. The weak coupling between the power output of the positive-sequence control strategy and the damping control strategy to reduce voltage imbalance is elucidated. Then an improved damping control strategy is proposed, which can simplify the control difficulty. Simulation analysis of the 10-node asymmetric network shows that the proposed control strategy of the inverter can output active power and reactive power. At the same time, the voltage imbalance of the network is reduced.