Study on the Noise-Level Calculation Method for Capacitor Stacks in HVDC Converter Station

The capacitor stack is one of main acoustic noise sources in the high-voltage dc (HVdc) converter station. It is necessary and important to estimate the noise level of capacitor stacks before an HVdc converter station is constructed. In this paper, based on the analysis of capacitor noise generation mechanisms, the relationship between the vibration speed and sound pressure level of the capacitor is identified. The equation which can be used to calculate the noise level of capacitor stacks is derived. By applying mechanical force on the capacitor tank, the frequency-response function of the capacitor tank vibration is acquired. And then the noise level of capacitor stacks is calculated and compared with the measurement data. The results show that the noise level of the capacitor stack can be predicted effectively with the proposed calculation method.