The effect of PWM frequency on the effectiveness of protection against electric shock using residual current devices

In the paper spectral analysis of the distorted earth fault currents in circuits with variable speed drives is performed. The impact of these distorted currents on the fibrillation effect is evaluated. Effectiveness of protection against electric shock using residual current devices in circuits with variable speed drives for various PWM frequencies is discussed. Operational characteristic of the proposed residual current device is presented.