基于转子电流反馈与功率不平衡响应的高电压穿越控制策略

传统高电压穿越(high voltage ride through, HVRT)过程的实现主要是针对转子过电流或直流母线过电压的单一场景设计控制策略，容易产生控制盲区。为此，提出一种基于转子电流反馈与功率不平衡响应的高电压穿越控制策略。为抑制转子过电流，在检测定子电压和电流的基础上，通过分解定子磁链获得转子电流直流分量参考值，将转子回路实际电流作为反馈量抵消转子回路中的直流电流分量。另外，考虑到直流母线过电压容易导致高电压穿越失败，采用功率平衡关系式推导稳定直流电压所需的控制电流参考值。若控制电流超过变流器允许工作电流范围，则考虑将输出电流限值作为控制电流参考值以最大限度利用变流器控制能力，降低直流母线过电压。仿真结果表明：所提出的控制策略能在降低过电流以及直流母线过电压的同时确保良好的动态响应性能。

High voltage ride-through control strategy based on rotor current feedbackand power imbalance response

The realization of the traditional high voltage ride-through (HVRT) process is mainly to design a control strategy for a single scenario of the rotor overcurrent or the DC bus overvoltage. It is easy for these to cause failure. Hence, this paper proposes a high voltage ride-through control strategy based on rotor current feedback and power imbalance response. For the suppression of the overcurrent, on the basis of measuring the stator voltage and current, the DC-component of the rotor current reference value is achieved by decomposing the overall stator flux linkage, and the actual rotor current is considered as the feedback to counteract the DC-current component in the rotor. Moreover, as the DC-bus overvoltage is another key factor to worsen the HVRT, the power balance relationship is used to derive the control current reference value which can stabilize the DC voltage. If the control current exceeds the operational current range of the converter, then the output current bound is regarded as the control current reference value. This can not only make full use of the converter control capability but also reduce the DC bus overvoltage. Simulation results show that the proposed control strategy reduces the rotor overcurrent and DC bus overvoltage while ensuring superior dynamic response.