Abstract

This dissertation presents behavioral and performance verification and analysis of residual current devices (RCDs), as well as a proposal for the construction of a new RCD protection. The state of the art focuses over pre-existing design of the RCD and its behavior and response to the circuits with distorted (non-sinusoidal) earth fault currents. The study highlights the loopholes of the existing design and depicts the problem of unresponsiveness of the RCD against smooth DC, very low-frequency and very high-frequency earth fault currents. For this, most commonly used types (AC, A, B and F) of RCDs were exposed to a series of testing mechanism more extensive than required by standards. Considering the type of problem a new design has been proposed in this dissertation that can outperform the existing design and can trip at even DC and at high-frequency level (40 kHz). Again, comprehensive testing was conducted to assess the newly designed RCD’s response to such abnormal earth fault current. The test results confirms its efficiency and practicality for real world applications. Hence, the conclusion is provided that this new design is capable of performing its designated function to ensure electrical safety. This new design contributes towards an advancement in the field of low-voltage electrical safety and paves a way for more sensitive RCDs. Moreover, a patent application for this new solution has been submitted to the Polish patent office.

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