电压无功控制（voltage quality control，VQC）系统的主要目标是保证变电站电压合格率和无功基本平衡，是提高电能质量的重要保障。从基于十七区图的某变电站VQC系统发生的振荡现象入手，从定值和控制策略2个方面对造成振荡的原因进行了研究分析。最终发现电容器控制次数和平峰时段无功定值是导致振荡的主要原因，并针对性地对电容器控制策略及平峰时段定值进行了调整与完善。经过连续跟踪检查，证明该措施的有效性，从而解决了该变电站母线电压不合格点过多的问题，提高了电压合格率。

The main goal of voltage quality control (VQC) system is to ensure the qualified voltage and the balanced reactive power in substation, which is the important guarantee to improve power quality. According to the oscillation occurred in the VQC system of a substation based on seventeen-zone theory, the fixed value and control strategy were analyzed, and the control times of capacitor and the fixed value of reactive power during flat peak period were the main reasons of oscillation. So the control strategy of capacitor and the fixed value during flat peak period were adjusted and improved. Through continuous track inspection, the measures were proved effective, which can solve the problem of too many unqualified voltage points of bus line in substation and improve the qualified rate of voltage.