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Test principle of relay protection tester

time:2020/12/19   source:华天电力  reading:269 time

The relay protection tester mainly focuses on relays, microcomputer protections, and other protection devices for preventive tests. The recommended test modules for relay tests are: DC test, AC and DC test, AC test, differential test, differential harmonic test , Power impedance, power direction and impedance test, synchronization test, microcomputer protection test is mainly for line protection, generator and transformer group protection related tests, there are automatic quasi-synchronization devices, automatic switching devices, busbar differential protection related tests.


Circuit principle


1. The input AC220V power supply enters the T1 input terminal of the double carbon brush voltage regulator through the output control relay K1 through the insurance, and the power adjusted by the large knob of T1 enters the isolation transformer T2 (part-time current booster), and the current booster is output in three taps. , One tap is AC0-250V output, the rated current is 3A; the output voltage of this tap can output 0-350V DC voltage after rectification and filtering; the second one is 15V (10A), the tap is output by the sensor through the relay control all the way to 0 -10A AC current, one way outputs 0-500mA AC current through resistance, one way through relay conversion can output 0-10A or 0-500mA DC current; the second tap is 10V (100A) high current terminal, this tap passes through the sensor once The circuit can directly output 100A current. This circuit has a strong load capacity, but the output is slightly overloaded and cannot be in a high current state for a long time. The auxiliary circuit of the thermal relay calibrator and the auxiliary circuit of the relay protection test instrument are connected with The main circuit is the same. The AC220V power supply is insured and enters the voltage adjusted by the small knob of the double carbon brush voltage regulator T1. The isolation transformer T4 can directly adjust the output 0-20V or 0-250V AC voltage or 0-350V DC voltage. This circuit is rated The current is 1A, press the "output control" switch of the auxiliary circuit and adjust the small knob to output.


Protection Relay Test Set.png


2. Measuring circuit


The output of the main circuit adjusted by the large knob is AC "0-250V", "0-500mA", "0-10A", "0-100A", DC "0-350V", "0-500mA", "0- 10A" is converted by the relay on the circuit board in the device. Every time a file is switched, the corresponding output can be monitored. The "0-500mA" file is included in the "0-10A" file. When used, the output is in the "0-10A" file. "Double click is "0-500mA" monitoring.


3. Time measurement


The device has a built-in 6-digit display stopwatch. The electric stopwatch can be started internally or externally. When it is started internally, press the "output control" switch to start the stopwatch. The stopwatch can be stopped by short-circuiting the stopwatch terminal on the device panel. , The stopwatch has a separate power switch, and the stopwatch can be turned off when not in use.

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