1, repeated short circuit test
Test instruction
The output of the module is short-circuited under various input and output states. The module should be capable of protection or retraction. It should be repeatedly short-circuited several times. After the fault is removed, the module should be able to automatically resume normal operation.
Test Methods:
a, no-load to short-circuit: In the full range of the input voltage, the module from no load to short circuit, the module should be able to achieve the normal output current limiting or retraction, after the short-circuit elimination, the module should be able to resume normal work. Let the module repeatedly work from no-load to short-circuit. The short-circuit time is 1s, the release time is 1s, and the duration is 2 hours. After this, the short circuit is released and it is judged 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 achieve normal output current limiting or retraction, after the short circuit is eliminated, the module should be able to resume normal work. Keep the module from full load to short circuit and keep it short for 2 hours. Then release the short circuit to determine whether the module can work normally.
c, short circuit boot: the module's output short circuit first, and then listed on the power, and then within the input voltage range of the module, the module should be able to achieve normal current limit or retraction, short-circuit fault elimination, the module should be able to return to normal work, After repeating the above test 10 times, let the short circuit be released and determine whether the module can work normally.
judgement standard:
After the above test, the power module can boot normally; the inspection of the boot, the circuit board and other parts have no abnormal phenomenon (such as whether the input relay is in shock during the process of short circuit, etc.), qualified; otherwise unqualified.
2, repeated switch testing
Test instruction:
When the output of the power supply module has the maximum load, the input voltage is 220v, (input overvoltage point -5v) and (input undervoltage point +5v), and the input repeats the switch to test the performance of the power supply module repeatedly switching on and off.
Test Methods:
a, the input voltage is 220v, the power module is fast with the maximum load, use the contactor to control the voltage input, close 15s, disconnect 5s (or can use ac source to simulate), continuous operation for 2 hours, the power module should be able to work normally;
b. The input voltage is the overvoltage point -5v. The power supply module has the maximum load. Use the contactor to control the voltage input. Close 15s and disconnect 5s (or use the ac source for simulation). The power supply module should be able to operate normally for 2 hours. jobs;
c, the input voltage is undervoltage point -5v, the power module with the maximum load, with the contactor control voltage input, combined 15s, disconnected 5s (or can be simulated using ac source), continuous operation for 2 hours, the power module should be able to normal jobs.
Judgment criteria:
In the above tests, the power supply module is working properly. After the test, the power supply module can work normally. The performance does not change significantly and it is qualified. Otherwise, it fails.
3, enter the low pressure point test
Test instruction:
The setback of the input undervoltage protection of the primary power supply module often occurs when the input voltage is low and close to the undervoltage point of the primary power supply module. When the load is undervoltage, the load is off, and the load is discharged due to the internal resistance of the power supply. The voltage will rise after the switch off, which may cause the power module to repeatedly develop at low voltage.
Test Methods:
The power module runs with full load. The input voltage changes slowly from (input undervoltage point -3v) to (input undervoltage point +3v). The time is set to 5 to 8 minutes. The cycle is repeated and the power supply module should be able to work normally and continuously. At least 0.5 hours, no significant changes in the power module performance.
judgement standard:
Once the power module is operating normally and continuously, there is no obvious change in performance after at least 0.5 hours, and it is qualified; otherwise, it is unqualified.
4, input transient high voltage test
Test instruction:
The pfc circuit adopts the average value circuit for undervoltage protection. Therefore, when transient high voltage is input, the pfc circuit may be quickly protected, resulting in damage. Test the stability of the power module under transient conditions to evaluate reliability. .
Test Methods:
a, rated voltage input, using double-trace oscilloscope test input voltage waveform and overvoltage protection signal, the input voltage jumps from the limit power point plus 5v to 300v, and reads out the number of cycles of the first 300v overvoltage protection from the oscilloscope as the following The basis of the test.
b, rated input voltage, power module with full load operation, superimposed on the input 300v voltage jump, superposition of the number of cycles (n-1), superimposed frequency of 1 / 30s, a total of 3 hours of operation.
judgement standard:
The primary power supply module can operate stably under the above conditions without any damage or other abnormal phenomena. It is qualified; otherwise, it is unqualified.
5, input voltage drop and output dynamic load
Test instruction:
During the actual use of a module, when the input voltage drops, the power module suddenly increases the load limit
It may happen that the power device and the magnetic element work in the state of maximum transient current. The test can verify the rationality of the circuit and software design such as control timing and current limit protection.
Test Methods:
a. Adjust the input voltage to transition between undervoltage point +5v (5s duration) and overvoltage point -5v (5s duration), and adjust the output to the maximum load (maximum rated capacity, duration 500ms) Jump between no load (500ms duration), run for 1 hour;
b, the input voltage is adjusted to undervoltage point +5v (duration of 5s), overvoltage point -5v (duration of 5s) between the jump, the output is adjusted at the maximum load (maximum rated capacity, duration is 1s), Jumps between no load (500ms duration) and runs for 1 hour.
judgement standard:
Under the above conditions, it should be able to operate stably without any damage or other abnormal phenomena. It is qualified; otherwise it is unqualified. If there is any damage, record the problem and provide the basis for analyzing the cause of the damage.
6. High-pressure no-load, low-pressure, limited-flow operation test
Test instruction:
High-voltage no-load operation is the test module's loss situation, especially the module with soft-switching technology. Under no-load conditions, the soft switch becomes a hard switch, and the loss of the module increases accordingly. The low-voltage full-load operation is the loss of the module when the test module is at the maximum input current. Under normal conditions, the module has the lowest efficiency at low-voltage input and full-load output. At this time, the heating of the module is the most serious.
Test Methods:
a. Adjust the input voltage of the module to the input overvoltage protection point -3v. The output of the module is the lowest output voltage. Run at no load. At this time, the duty cycle of the module is minimum.
2 hours of continuous operation, the module should not be damaged;
b. Adjust the input voltage of the module to the undervoltage point +3v. The output of the module is the inflection point of the highest output voltage. At this time, the duty cycle of the module is maximum, and the module should not be damaged if it is continuously operated for 2 hours.
c. Adjust the input voltage of the module to the input voltage at the lowest point of efficiency. The output of the module is the inflection point of the highest output voltage. For continuous operation for 2 hours, the module should not be damaged.
d, the module's input voltage is adjusted to over-voltage point -3v, the module's output is the highest output voltage inflection point, this time the maximum duty cycle of the module, continuous operation for 2 hours, the module should not be damaged;
e. Adjust the input voltage of the module to the input voltage at the lowest point of efficiency. The output of the module is the inflection point of the highest output voltage. For continuous operation for 2 hours, the module should not be damaged.
Note: The above test must be performed at the maximum operating temperature specified in the specification.
judgement standard:
Working under the above conditions, the module did not appear damaged and qualified; otherwise it failed.
7, power special waveform test
Test instruction:
Verify that the power supply module can operate stably with spikes, burrs, and harmonics that may be caused by waveform distortion in the power grid. The following waveforms must be entered for testing:
(1) Glitch input test waveform
Grid glitches are the most common waveforms in the power grid. There is no limit to the size and amplitude of the glitches. Under normal circumstances, the input of the oscillating wave and the ringing input waveform can basically simulate the glitch input in the power grid, but it still needs Do the following glitch input test
Features: Power grid spikes have overshoot and will fall to 0v, overshoot and drop pulse width is very narrow, generally not more than 100ms, overshoot amplitude generally does not exceed 100v. The phase of the drop is not limited to the peak point, but it can occur at any phase. This kind of waveform is very common in the actual power grid, and turning on any switch will cause this phenomenon.
(2) Voltage Clipping Waveform Input
This kind of waveform is also very common in the power grid. Its characteristic is that the grid suddenly drops to 0v from an indefinite phase and does not resume until the next half-wave starts. In the iec1004-4-11, the drop of the waveform starts from more than half cycle, but there are still many similar waveforms with less than one half of the drop time in the actual power grid. The test requires that the input voltage waveform start to fall from 90 degrees, drop 1/4 cycle, and work for 2 hours.
(3) The half of the power grid steeply rises to double the voltage. This waveform is mainly used to simulate the resonant overvoltage suddenly appearing in the actual power grid. In this case, the input overvoltage protection circuit of the module does not work. This impact is dangerous for circuits with pfc. Test content: a, in the case of an input voltage of 180V, output full load, simulate the waveform with ac source, require 180v to work for 3 minutes, then the voltage suddenly increases to 380v for 100ms, then restores to 180v, let the module in this In case of prolonged work for 1 hour, it should not be damaged; b. Set ac source to make the input voltage 0v for 5 minutes, then the voltage suddenly increases to 380v for 100ms, then restores to 0v, let the module be long in this case Work time 1 hour, should not be damaged.
Test Methods:
Power is supplied to the module using the ac source, and the module is fully loaded. The ac source is used to simulate spikes, glitches and harmonics voltage inputs. Each special voltage input operates for 2 hours and the input current and output voltage are measured. The module should be able to run stably. Please pay attention to x capacitors, auxiliary power supply, soft-start resistance and other possible problems in the test.
Measure to judge:
In practice, spikes, burrs, and harmonic voltages may operate stably, without damage, and pass; otherwise, they will fail.
body;
8, active pfc performance test
Test instruction:
Power modules with source pfc are more sensitive to grid spikes, spikes, and harmonics and should be thoroughly tested.
Test Methods:
Using ac source AC source as input voltage source, output with half load and full load respectively, test the input current waveform and voltage waveform, and monitor the voltage after pfc; test the input voltage and current of the power grid in spikes, glitches and harmonics Phase and amplitude relationship; measure the current and voltage of the PFC switch to verify the safety of the switch and other power devices and the ability of the current tracking voltage to change in full voltage range and glitches, spikes, and harmonics.
judgement standard:
The pfc test can be used as a reference for reliability. When a serious problem occurs, it should be resolved in time.
9, operating voltage test
Test instruction:
There are many kinds of operating over-voltage in the power grid, among which the most common time and load circuit closes the over-voltage, and the over-voltage threat to the module is also greater. This test is to verify the module's ability to resist over-voltage.
Test Methods:
The simulation of the overvoltage line is very simple, the principle is as follows:
The inductance parameter is 10mh (for reference: ees module test method, there is no grounding capacitance, input resistance and inductance in series, the resistance value is 0 ohms, the inductance is 8mh and the resistance is 79 ohms, and the inductance is 10mh. ), The capacitance is 16.7uf, and the test waveform is as follows (not shown).
The device to be tested is connected across the capacitor. At the moment of k closing, an overvoltage will be generated at both ends of the capacitor to simulate the damage of the overvoltage to the device during the power-on process. As a limit test item, the input is connected to the l and n lines, and the device to be tested is connected to both ends of the capacitor. The frequency is frequently switched on and off. The repetition frequency is 1/5 minutes, and the continuous test is 5 hours. For a three-phase input device, the input is connected to line l and line l. The device to be tested is connected to both ends of the capacitor. The repetition frequency is 1 time/5 minutes, and the continuous test is 2 hours.
judgement standard:
In the test process, a short-term function degradation or performance degradation occurs, but it can be automatically restored, but it is unqualified if the performance is permanently degraded or requires manual intervention to recover.
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