###### Abstract  
With the increasing proportion of wind power access year by year, it brings many challenges to the voltage stability of power systems. In order to maintain the stability of the voltage in the power grid, it is impossible to take into account the regulation ability and economy when a single reactive power compensation device is installed. In this paper, a combined reactive power compensation device was installed, which is composed of a static var generator (SVG) and a parallel capacitor bank. The SVG has the characteristics of fast and smooth adjustment, and the application of the capacitor bank reduces the overall investment cost and has a great economy. The modal analysis method was used to find the optimal installation position for the reactive power compensation device. The improved particle swarm algorithm was used to optimize the capacity of the optimal reactive power compensation device to ensure the best performance of the compensation device. Finally, by formulating the control strategy of the combined reactive power compensation system, the reliable switching of the compensation device is controlled. The PSCAD simulation software was used to model the power grid in the Hami area, and six different configuration programs were set for static voltage stability simulation verification and three different configurations. The program was simulated and verified for transient voltage stability, and comparative analysis showed that the proposed method was correct, which strongly supports the voltage stability of the region and meets the demand of reactive power compensation of the power grid. This provides a good reference program for other wind power gathering areas. static var generator (SVG); parallel capacitor bank; combined reactive power compensation device; improved particle swarm algorithm Article  
Research and Application of Combined Reactive Power Compensation Device Based on SVG+SC in Wind Power Gathering Area  
advantage of traditional reactive power compensation device SC and the continuous smooth adjustment ability of SVG device. According to the current research status, the authors of [7] proposes using SVC to replace the conventional reactive power compensation device, and rationally configuring the capacity of SVC to further ensure the stability of bus voltage. In order to evaluate the voltage support, the dynamic reactive power support is studied by the comprehensive analysis of time domain and frequency domain. Related scholars proposed that in the process of voltage static stability research, the corresponding reactive power compensation device should be added to the weak point of voltage, which can basically meet the requirements of wind power delivery in the Hami area to a certain extent. The authors of [8] put forward the optimization measures to install the corresponding series and parallel reactive power compensation devices on the top of the network channel, and carried out relevant research, analysis, and demonstration. The authors of [9,10] conducted a comparative analysis of the effect of reactive power compensation on the medium-voltage side compensation and low-voltage side of the UHV transformer. Although the operation of the UHV DC project was guaranteed, the DC near-region voltage was not analyzed. The authors of [11] rationalized the configuration of the capacity through SVC and conventional capacitor banks in order to minimize the total investment, but did not consider the best performance of the compensation device. In [12], the reactive power capacity of the large-scale wind power grid-connected system was calculated, and the recommended and unrecommended operation modes were analyzed. The authors of [13] studied the structure, coordinate control method, and parameter design of the hybrid system proposed for active power injection and non-active power (reactive, harmonic, and unbalanced power) compensation. The proposed hybrid system consists of a static var compensator (SVC) and a capacitively coupled grid-connected inverter (CGCI) (SVC//CGCI).