Zhang Wei ¹ Zhang Zhe ^1* Dai Y. Yi ^1* Dong Chen ^1* Yu Z. Jia ^1* Hu Yue ^2*

• ¹ State Grid Jiangsu Electric Power Co., LTD, Nanjing, Jiangsu Province, China
• ² China University of Mining and Technology, Xuzhou, Jiangsu Province, China

In the case of resistance-inductance lines in PV station area, the problem of voltage overstep is easy to occur. This article proposes a reactive power compensation control method to improve the voltage stability in the photovoltaic power plant area, which addresses the problem of voltage at the point of common coupling (PCC) exceeding the upper limit due to resistance circuits and exceeding the lower limit due to relatively insufficient reactive power output when the output active power is high. The idea is to achieve dynamic adjustment of PCC voltage by paralleling a static reactive power generator (SVG) at the grid connection point and using a variable droop control method. In addition, a reactive power optimization method based on improved particle swarm optimization (IPSO) algorithm is proposed to address the changes in power flow caused by photovoltaic integration in the distribution network system. The proposed improvement method not only effectively reduces network losses but also significantly improves voltage stability.Reference values of the DC voltage.Udc DC voltage.Proportional and integral gain of the voltage regulator.Reference values of the reactive power.Reactive power provided by SVG.Proportional and integral gain of the reactive power regulator. idref Active current reference. iqref Reactive current reference. id, iq Active and reactive components of the current output by SVG. ud, uq d-axis and q-axis voltage of PCC. iCd , iCq d-axis and q-axis components of capacitive current. 𝑈𝑈 ̇𝑔𝑔 k Number of iterations. kmax Maximum number of iterations. r Random number.