Surge protector performance detection device and method

Abstract

The invention discloses a surge protector performance detection device and method, which relate to the field of safety protection. The device comprises a current transformer, a resistor, a voltage detection unit and a comparison unit. The wire of a surge protector winds the current transformer. The secondary winding of the current transformer is connected in series with the resistor. The measurement end of the voltage detection unit is connected to the two ends of the resistor. The output end of the voltage detection unit is connected to a first comparison input end of the comparison unit. A second comparison input end of the comparison unit inputs a preset alarm value. The voltage detection unit measures the voltage effective value of the resistor in real time, and transmits the voltage effective value to the comparison unit. The comparison unit compares the voltage effective value with the preset alarm value, measures the duration of the voltage effective value, and determines that the performance of the surge protector is deteriorated when the voltage effective value is greater than the preset alarm value and the duration of the voltage effective value is greater than a durationthreshold. Surge protector performance detection is realized.

Description

technical field [0001] The invention relates to the field of safety protection, in particular to a performance detection device and method for a surge protector. Background technique [0002] The Surge Protective Device (SPD for short) used in the low-voltage power distribution system of the communication station is the main lightning protection device of the communication power system, which can effectively reduce the lightning disaster loss of the communication network. A large number of voltage-limiting power supply SPDs with Metal Oxide Varistors (MOV for short) as the main protection device are installed in the communication station. Varistor is a metal oxide semiconductor overvoltage suppression device with zinc oxide (ZnO) as the main component. Its lightning protection principle is: when the voltage across the varistor is less than the nominal on-voltage State, the current flowing through it is very small (this current is called leakage current, normally in the orde...

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Problems solved by technology

[0003] The existing power supply SPD has the following problems: After a period of use of the voltage-limiting SPD, the performance will decline due to natural aging and multiple lightning strikes, and the leakage current of the varistor will gradually increase (this process is called "SPD degradation") , when the leakage current increases to a certain level (generally on the order of tens of mA), the thermal balance cannot be maintained (the large leakage current causes the varistor to heat up, and when the heat generation is greater than the heat dissipation, the thermal balance cannot be maintained), and eventually self-burning

[0004] The current technology mainly uses the heat generated during the deterioration process of the varistor to blow off the temperature insurance connected in series in the SPD circuit or melt the low-temperature solder to separate the varistor from the protected main circuit. The tripping technology is difficult to be 100% reliable, and SPD fires and spontaneous combustion incidents occur from time to time

Another solution is to manually measure the leakage current value of SPDs at intervals. However, if the SPDs running on the current network are to be tested one by one, power failure or even cutover will be required, which will cost a lot in terms of manpower, material resources, and time. Probably during the period between the two tests, the SPD had deteriorated and caught fire

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