Voltage dip tolerance test

2018-07-23 12:09:35 SUSHI GUANGBO TEST TECHNOLOGY CO.,LTD 已读
Voltage dip tolerance test
 
Voltage sag, short-term interruption and voltage change immunity test cause
 
Voltage sag and short-term interruption are caused by sudden changes in the power grid, power facilities, or sudden changes in load. In some cases there may be two or more consecutive dips or interruptions. The voltage change is caused by a continuous change in the load connected to the grid.
 
Voltage sag, short interruption and voltage change immunity test purpose
 
The standard specifies different types of experiments to simulate the abrupt effects of voltage in order to establish a general criterion for evaluating the immunity of electrical and electronic equipment when subjected to such changes.
 
Voltage dip, short interruption and voltage variation immunity test level
 
Voltage sag short-term interruption test preferred test level and duration
 
Category a Test level and duration (ts) for short interruptions (50Hz/60Hz)
Class 1 is performed once according to equipment requirements
Class 2 0% Duration 250/300 weeks
Category 3 0% Duration 250/300 weeks
X class b X
Voltage sag short-term interruption test preferred test level and duration
 
Voltage test level
Time required for voltage reduction (td)
Reduce voltage maintenance time (ta)
Time required for voltage increase (ti) (50Hz/60Hz)
70%
mutation
1 cycle
25/30 cycle b
Xa
specific
specific
specific
a “Class X” is defined by the relevant Standardization Technical Committee.
 
b “25/30 cycle” means “25 cycles for 50Hz test” and “30 cycles for 60Hz test”.
 
Voltage sag short-term interruption test method
 
When the output voltage is 80% of the nominal value, the above requirements only need to be tested during the maximum duration of 5s.
 
When the output voltage is 70% and 40% of the nominal value, the above requirements only need to be tested during the maximum duration of 3s.
 
Rise and fall times, as well as overshoot and undershoot, should be at phase angles 90o and 270o, from 0% to 100%, 100% to 80%, 100% to 70%, 100% to 40%, and 100% to 0. % performs handover verification.
 
The accuracy of the phase angle should be checked from 0% to 100% and 100% to 0% in 9 phase angles from 0o to 360o in 45o increments. And at phase angles 90o and 180o, from 100% to 80%, then 80% to 100%, 100% to 70% and 70% to 100%, and 100% to 40% and 40% to 100% for handover verification.
 
The EUT shall perform three voltage sag or interruption tests in sequence for each selected test level and duration. The minimum discontinuity of 10 s (interval between tests) shall be tested in each typical mode of operation. .
 
For voltage sag, the change in supply voltage occurs at voltage zero crossings, and is considered by the relevant professional standardization technical committee or individual product specifications to require additional testing. Each phase is preferred to 45o, 90o, 135o, 180o, 225o. , 270o, and 315 o. For short interruptions, the relevant professional standardization technical committees specify the angle according to the worst case. If not specified, it is recommended to select one phase and test when the phase angle is 0o.
 
For the short-term interruption test of the three-phase system, three corresponding tests are carried out simultaneously.
 
For the voltage sag test of a single-phase system, the voltage is tested according to the terms, which means that a series of tests are carried out.
 
For the voltage sag test of a three-phase system with a neutral line, one voltage is measured separately each time (phase line, phase one phase), which means that tests are performed on six different systems).
 
For the voltage sag test of a three-phase system without a neutral line, the phase-phase voltage is tested separately each time according to Clause 5.1, which means that three different series of tests are performed).
 
Note: For a three-phase system, during the sag of the phase-to-phase line voltage, the voltage change is preferably performed on one or two other voltages.
 
For EUTs with more than one power cord, each power cord should be tested separately.
 
For each of the specified voltage change tests for the EUT, three tests shall be performed in the most typical mode of operation with an interval of 10 s.
 
Laboratory climatic conditions
 
Tests should not be carried out within the normal operating range of the equipment specified by the manufacturer of the EUT and the test equipment, if the relative humidity is so high that it causes condensation on the EUT and the test equipment.
 
Voltage sag short-term interruption test result
 
a) normal performance within the limits specified by the manufacturer, the entrusting party or the purchaser
 
b) Temporary loss or reduction of function or performance, but self-recovery after cessation of harassment, without operator intervention;
 
c) temporarily lost or reduced function or performance, but requires operator intervention to recover;
 
d) Loss of functionality or performance degradation due to equipment hardware or software corruption, or data loss.
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