Switching power supply repeated short circuit test and repeated switching machine test

1, repeated short-circuit test

Test specification

If the output of the module is shorted in various input and output states, the module should be able to realize protection or retraction. If the module is shorted repeatedly, it should automatically resume normal operation after the fault is removed.

Test method

A. No load to short circuit: within the full range of input voltage, switch the module from no load to short circuit. The module should be able to realize output current limiting or retraction normally. After the short circuit is removed, the module should be able to resume normal operation. Let the module repeatedly work from no-load to short circuit, short circuit time is 1s, release time is 1s, the duration is 2 hours. After this, short circuit release, judge whether the module can work normally.

B. Full load to short circuit: in the full range of input voltage, the module from full load to short circuit, the module should be able to realize output current limiting or retraction normally, after the short circuit is removed, the module should be able to resume normal operation. Let the module go from full load to short circuit and then stay short for 2 hours. Then short circuit release, judge whether the module can work normally.

c. Short-circuit startup: the output of the module is shorted first, then powered on, and then powered on within the input voltage range of the module. The module should be able to achieve normal current limiting or retraction, and after the short-circuit fault is removed, the module should be able to resume normal operation.

Decision criteria

After the above test, the power module can work normally after starting; Open the case to check that there is no abnormal phenomenon in the circuit board and other parts (such as whether the input relay is stuck in the process of short circuit, etc.), qualified; Otherwise, it is not qualified.

2, repeated switch machine test

Test specification

When the output power module has the maximum load, the input voltage is 220v (input overvoltage point -5 V) and (input undervoltage point +5v), the input is switched on and off repeatedly to test the performance of the power module on and off repeatedly.

Test method

a, the input voltage is 220v, the power module fast with the maximum load, use contactor to control the voltage input, close 15s, disconnect 5s(or can use ac source for simulation), continuous operation for 2 hours, the power module should be able to work normally;

b. The input voltage is the overvoltage point -5v, and the power module has the maximum load. Use contactor to control the voltage input, and turn off for 15s (or you can use ac source to simulate).

c, the input voltage is undervoltage point -5v, the power module has the maximum load, use contactor to control the voltage input, close 15s, disconnect 5s(or can use ac source to simulate), run continuously for 2 hours, the power module should be able to work normally.

Decision criteria

In the above test, the power module works normally. After the test, the power module can work normally with no obvious change in performance, qualified; Otherwise, it is not qualified.