Residual current device

Abstract

Embodiments of the present invention disclose a Residual Current Device (RCD). The RCD includes: a first zero-sequence current transformer, used for passively detecting a residual current signal of a current-carrying conductor; a first processing circuit connected to the first zero-sequence current transformer, used for acquiring the residual current signal from the first zero-sequence current transformer, and actively processing the residual current signal, where the first processing circuit is connected to a power source; a second zero-sequence current transformer, used for actively detecting the residual current signal appearing on the current-carrying conductor; and a second processing circuit connected to the second zero-sequence current transformer, used for acquiring the residual current signal from the second zero-sequence current transformer, and actively processing the residual current signal, where the second processing circuit is connected to the power source. The RCD can make a very good response within a wide frequency range, and achieve better frequency response characteristics.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a residual current device. Background technique [0002] Residual Current, also known as excess current, residual current or leakage current, refers to the current in which the vector sum of the currents of each phase (including the neutral line) in low-voltage distribution lines is not zero. Residual current is extremely harmful. In electrical fire accidents, accidents caused by excess current account for about 1 / 2 of electrical fire accidents, which shows the severity and universality of excess current. [0003] The residual current device (Residual Current Device, RCD) is a protector that turns on, loads and disconnects the current under normal working conditions, and when the residual current of the circuit exceeds the normal range, it will cause an action to disconnect the main circuit. The residual current device is essentially a leakage current protection device, and...

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Problems solved by technology

However, these attempts generally have various problems such as complex circuit design and high power consumption.

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