A Method of Measuring Switching Overvoltage Based on the CVT Capacitive Current Integration Principle

Switching overvoltage will destroy the resonance condition inside the capacitor voltage transformer (CVT), reducing the accuracy of the CVT measurement of switching overvoltage. Some methods can accurately measure the switching overvoltage, but they need to modify the CVT structure, and the operation process is complex and expensive. To solve this problem, this article proposes a switching overvoltage measurement method based on the CVT capacitive current integration principle. This method uses the compound Simpson integration algorithm to integrate the capacitive current to realize the measurement of the switching overvoltage. On this basis, the effect of capacitive current data loss and the initial value of voltage integration on this method is considered to improve the measurement accuracy. Furthermore, the accuracy of this method for measuring the switching overvoltage is verified by simulations and experiments. Compared to other methods, this method has the advantage of a simple measurement principle, lower transformation complexity, and easy implementation.