用ATP-EMTP研究1000kV CVT的暂态特性

为研究1000kV电容式电压互感器(CVT)的暂态特性,在分析其非线性元件的饱和特性后,利用电磁暂态计算程序ATP-EMTP建立了1000kV CVT计算模型。对不同阻尼电阻值下的铁磁谐振进行仿真,得出了理想的阻尼电阻值,计算结果与实际采用阻尼电阻值相吻合;在不同合闸相角下分别对CVT铁磁谐振以及瞬变响应进行仿真计算,铁磁谐振过电压波形的仿真结果与试验结果基本一致,得出最严重情况下的谐振过电压倍数和二次瞬变响应电压值。研究结果不仅可以实现1000kV CVT设计阶段的暂态性能参数控制,同时解决了试验无法模拟现场实际条件的矛盾,为晋东南-南阳-荆门1000kV特高压交流试验示范工程中CVT暂态特性提供考核手段之一。

Transient Characteristics of 1000 kV Capacitor Voltage Transformer Based on ATP-EMTP

In accordance with the equipment insulation and the present status of China Ultra-high voltage project, capacitor voltage transformer is chosen for voltage transformer in Jindongnan-nanyang-jinmen 1000 kV UHVAC pilot project of China. To study the transient characteristics of 1000 kV CVT, this paper analyzes the saturated characteristic of nonlinear elements, such as the intermediate transformer and saturated reactor, establishes the calculated model of 1000 kV CVT based on ATP-EMTP, calculates the ferromagnetic resonance overvoltage in different damping resistor value, and gets the optimally damping resistor value which is just the damping resistor value used in project. The wave of secondary-output ferroresonance overvoltage in simulation accords with the wave in test. This paper also calculates the ferroresonance overvoltage and transient response overvolage at different switch phase angles, gets the maximal multiple of resonance overvoltage and value of secondary transient response voltage. The transient performance parameter is selected in the stage of prototype design, and a scientific and accurate diagnostic tool of CVT transient performance is presented, which resolves the contradiction that the test can not imitate the field actual conditions.