Device for evaluating small current variable by apparent power

Abstract

The invention discloses a device for evaluating a small current variable by apparent power, and belongs to the technical field of electromagnetic measurement. The device comprises a current sensor, and is characterized in that the current sensor is used for detecting the current on a line; a current sampling circuit in an apparent power sensor collects the detected current; an arithmetic unit multiplies the collected current by a given apparent voltage to obtain apparent power, and accumulates the apparent power in real time to obtain apparent electric quantity; and a central processing unit reads the apparent electric quantity according to a set time interval, calculates the variation of the apparent electric quantity in each time period, compares the relative variation amplitude of the apparent electric quantity variations in two adjacent time periods, and makes a decision of continuing to detect or report the information. The judgment device judges the change trend of damage energyin the line according to the change amplitude of the apparent electric quantity in the adjacent same-length time periods, and can upload a signal when the increase amplitude of the apparent electric quantity is relatively large so as to remind a worker to take security check measures.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic measurement, and in particular relates to a device for judging small current variables by using apparent power. Background technique [0002] Since the end of the 1960s, in order to strengthen the safety of electricity use, my country has gradually adopted protection measures in the power system, among which the leakage protector is a general technical means. The leakage protector detects the abnormal current or voltage signal of the monitoring equipment or the circuit. When the detected signal reaches its set threshold, it prompts the actuator to act to cut off the power supply, so as to avoid accidents such as burning out electrical appliances, fire or electric shock, so as to ensure personal safety and health. To ensure the safety of electrical equipment and achieve the purpose of protection. [0003] Later, some also adopted the method of small current grounding, which installed a zer...

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Problems solved by technology

[0005] It can be seen that technologies such as leakage protectors and small current grounding can no longer meet the needs of the development of power grids. It is urgent to develop a new detection technology that can actively find problems to avoid disorderly power outages, achieve energy saving in production, and reduce waste.

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