Reactive Power and AC Voltage Control of LCC HVDC System With Controllable Capacitors
Reactive Power and AC Voltage Control of LCC HVDC System With Controllable Capacitors
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DOI：
10.1109/tpwrs.2016.2557342
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发表时间：
2017
影响因子：
6.6
通讯作者：
Ying Xue;Xiao-Ping Zhang
中科院分区：
文献类型：
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作者：
Ying Xue;Xiao-Ping Zhang
传统的基于线路换相换流器（LCC）的高压直流（HVDC）系统无法控制其无功功率和端电压。本文研究了含可控电容器的LCC直流输电系统逆变器侧无功功率和交流电压的控制问题。利用系统在负熄弧角下运行的能力，实现大范围的无功控制，特别是无功输出能力。关于逆变器AC端电压或无功功率控制，在整流器侧的不同控制可能性中，有功功率控制是期望的，因为有功功率传输的大的变化是非常不利的。首先进行了详细的理论分析，以显示无功功率的可控性，并根据所需的控制范围选择电容器电压水平。此外，提出了一种新的负消光角测量方法。通过实时数字仿真器（RTDS）的仿真结果验证了所提出的系统的无功/电压控制能力的有效性。为了验证无功电压控制的有效性，在RTDS中建立了CCC HVDC和LCC HVDC与SVC的仿真模型，并进行了仿真比较。此外，通过对改进的两区域四机交流电力系统的仿真结果，证明了该方法对电力系统交流电压控制的贡献。
It is well known that traditional line-commutated converter (LCC) based high voltage direct current (HVDC) system is not able to control its reactive power and terminal AC voltages. This paper investigates the reactive power and AC voltage control at the inverter side of the LCC HVDC system with controllable capacitors. The system's ability of operating under negative extinction angle is utilized to achieve a wide range of reactive power control and, in particular, the ability of exporting reactive power. In connection with the inverter AC terminal voltage or reactive power control, among different control possibilities at the rectifier side, active power control is desirable since large variations of active power transfer is very unfavorable. Detailed theoretical analysis is carried out first to show the reactive power controllability, and the capacitor voltage level is selected based on the desired control range. In addition, a new extinction angle measurement approach is proposed for negative extinction angle measurements. The effectiveness of the reactive power/voltage control capability for the proposed system is validated through simulation results using Real-Time Digital Simulator (RTDS). To verify the effectiveness of the reactive power and voltage control, CCC HVDC and LCC HVDC with SVC are also set up in RTDS, and simulation comparisons are made. Furthermore, contribution to AC voltage control in power system using the proposed method is demonstrated through simulation results of the modified two-area four-machine AC power system.