虚拟惯量控制对提高电网一次调频稳定性的影响

Effect of Virtual Inertia Control on the Stability of Primary Frequency Regulation

大规模风能通过输电线路接入交流系统之后,会使得电网系统惯量逐渐减小,导致系统阻止频率突变的能力下降;同时大容量负荷的切换,也会使电网频率大幅度振荡。为了研究证实虚拟惯量控制对稳定电网频率的支持作用,建立了110 k V直流输电系统仿真模型,利用直流输电电容仿效出虚拟惯量常数加入控制系统中,从而改变电网惯性,改善频率抗干扰能力。仿真结果表明,采用虚拟惯量控制后,在系统功率变化时,调频回路立即动作,响应时间不到0.2 s,畸变幅值远远小于调频要求的1%,增强了一次调频抗干扰能力。

After large-scale wind power connecting to AC system through transmission lines, the inertia of grid system will gradually decrease, and the effect of the system on keeping frequency from sudden change may reduce. Furthermore, the switch with large -capacity load will cause great oscillation of the power system frequency. In order to research and prove the support effect of virtual inertia control on stable grid frequency, it constructed a digital simulation model of 110 kV HVDC system, and utilized DC transmission capacitance to imitate virtual inertia and then put it into control system, thus the grid inertia was changed and the anti-interference ability of frequency was improved. Simulation results indicate that with the virtual inertia control, as the system power changing, the frequency modulation circuit immediately responds, the response time is less than 0.2 s and distortion amplitude is far less than 1%, thus it enhances the anti-jamming capability of primary frequency regulation.