| 引用本文: | 勾奕昀,郑竞宏,刘 壮,丁禹升.基于锁相环相位补偿的光伏逆变器低电压穿越快速无功控制[J].电力系统保护与控制,2024,52(24):85-96.[点击复制] |
| GOU Yiyun,ZHENG Jinghong,LIU Zhuang,DING Yusheng.A low voltage ride-through rapid reactive power control method for a PV inverter based on phase compensation of a phase-locked loop[J].Power System Protection and Control,2024,52(24):85-96[点击复制] |
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| 摘要: |
| 在低电压穿越故障恢复阶段，针对弱网下光伏并网系统无功回撤速度慢易导致暂态过电压的问题，提出了基于锁相环相位补偿的光伏逆变器低电压穿越快速无功改进控制策略。首先从相位跳变、锁相环动态、电网强度几个方面分析了常规光伏逆变器无功回撤速度不足的原因。然后根据光伏逆变器出口内电势与锁相环相角关系的机理分析，提出了基于相位补偿的锁相环改进控制策略。从无功控制需求出发推导了补偿相位的确定方法，并建立光伏并网系统单机电磁暂态仿真模型，验证了所提出的改进控制策略在三相对称、不对称、线路切除等故障场景下的有效性。最后基于RT-Lab搭建光伏发电并网系统半实物仿真平台，进一步验证了改进控制策略的有效性。该控制策略使光伏逆变器获得了更快的无功回撤能力，可有效抑制低电压故障恢复阶段的暂态过电压问题。 |
| 关键词: 光伏逆变器 锁相环 相位补偿 前馈控制 低电压穿越 暂态无功特性 |
| DOI：10.19783/j.cnki.pspc.240019 |
| 投稿时间：2024-01-04修订日期：2024-07-08 |
| 基金项目:国家重点研发计划项目资助(2021YFB2400500) |
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| A low voltage ride-through rapid reactive power control method for a PV inverter based on phase compensation of a phase-locked loop |
| GOU Yiyun,ZHENG Jinghong,LIU Zhuang,DING Yusheng |
| (Department of Electrical Engineering, Tsinghua University, Beijing 100084, China) |
| Abstract: |
| There can be a problem of transient overvoltage caused by the slow reactive power retrace speed of a PV grid-connected system with a weak power grid in the voltage recovery stage. Thus this paper presents an improved control strategy of fast reactive power for a PV inverter based on phase-locked loop (PLL) phase compensation. First, the reasons for the slow reactive power recovery speed of PV inverters are analyzed from the aspects of phase jump, PLL dynamics and power grid strength. Then, from a mechanism analysis of the relationship between modulating voltage of PV inverters and the phase angle of PLL, an improved PLL control strategy based on phase compensation is proposed. From the requirements of reactive power control, a method of determining the compensation phase is derived. A electromagnetic transient simulation model of the photovoltaic grid-connected system is established, and the effectiveness of the proposed improved control strategy is verified in three phase symmetric, asymmetric, line cutting and other fault scenarios. Finally, based on RT-Lab, a hardware-in-loop simulation platform of a PV grid-connected system is built to further verify the effectiveness of the improved control strategy. The control strategy enables the PV inverter to obtain faster reactive power recovery, and can effectively suppress the transient overvoltage problem in the low voltage fault recovery stage. |
| Key words: PV inverter phase-locked loop phase compensation feed-forward control low voltage ride through transient reactive power characteristic |
