Inverse time current limiting electrical fire prevention and control device and method

Abstract

The invention discloses an inverse time current limiting electrical fire prevention and control device and method. The device comprises a control unit, a solid-state switch, an analog signal conditioning circuit and a current detection unit used for detecting instantaneous alternating current information of the protected loop. The output end of the current detection unit is connected with the input end of the control unit through the analog signal conditioning circuit. The output end of the control unit is connected with the solid-state switch. The protected loop is connected with a power supply through the solid-state switch. The device and the method have the inverse time characteristic, and the volume is small.

Description

technical field [0001] The invention belongs to the field of electrical fire prevention and control, and relates to an inverse time-limit current-limiting electrical fire prevention and control device and method. Background technique [0002] When a short circuit or overload fault occurs in the power line, the current passing through the wire will increase significantly, resulting in overheating of the wire and damage to the insulation performance, causing electrical fire hazards or directly causing electrical fires. At present, conventional electrical fire-proof current-limiting protectors, when the current value I(t) of the protected line exceeds the short-circuit protection setting current value I S When the current value I(t) of the protected line exceeds When the overload protection setting current value stipulated in the subsection is delayed according to the delay time specified in the corresponding subsection, the solid state switch module breaks the overload curren...

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Problems solved by technology

Obviously, no matter how the current value of the protected line changes within the same protection setting current value, the delay action time of the solid-state switch unit is the same (for example, the current value of the protected line is within 1.0I e ~1.5I e When changing within the range, the delay action time of the solid-state switch unit is T 1.0 ), that is, there are cases where the overload current of the line is different but the delay time of the protection action is the same, which cannot accurately meet the requirements of the inverse time-limit characteristic (that is, the larger the overload current is, the shorter the delay time of the protection action) that the line protection should abide by. In practical applications poor protection

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