Voltage flicker test

Voltage flicker test
Introduction to voltage fluctuations and flicker
Electromagnetic Compatibility Limits Voltage variations, voltage fluctuations, and flicker limits for devices that are rated for less than or equal to 16A and unconditionally connected in a common low-voltage power supply system.
GB17626.2/EN61000-3-2 This section applies to each input current is less than or equal to 16A, intended to be connected to the phase voltage of 220V to 250V, frequency 50Hz public low-voltage power distribution system, and unconditionally connected electrical and electronic equipment.
Evaluation of short-term scintillation value Pat
The short-term flicker value of Pat is specified in IEC61000-4-15:2003.
Table 1 shows the selection of Pat evaluation methods that can be substituted for each other according to different voltage fluctuation types:
Table 1 evaluation method
Voltage fluctuation type
Pat evaluation method
All voltage fluctuations (online assessment)
Direct measurement
Defines all voltage fluctuations of U(t)
Direct measurement
According to Figure 5 to Figure 7, the voltage conversion characteristics are lower than 1 time per second.
Analytical method
Direct measurement
Isometric rectangular voltage change
Use the curve of Pat=1 in Figure 4.
Voltage fluctuation and flicker test limits
Some of the limits apply to voltage fluctuations and flicker at the power supply end of the device under test. This limit is measured or calculated according to the test conditions specified in Chapter 6 and Appendix A and in accordance with Chapter 4. A test that demonstrates compliance with the limits is considered a type test.
The following limits apply:
The value is not greater than 1.0;
The value is not more than 0.65;
The time during which the d(t) value exceeds 3.3% during the voltage change is not more than 500 ms;
Relative steady state voltage change dc does not exceed 3.3%;
The maximum relative voltage change dmax does not exceed:
a) 4%, no additional conditions;
b) 6%, the equipment is:
- manual switch, or
- Automatic switch more than 2 times a day, and after a power interruption, there is a delay to restart (delay not less than tens of seconds), or manually restart.
Note: The frequency of the cycle will be further limited by the Pat and Plt limits. For example, for a rectangular voltage change characteristic that produces 2 times per hour with a dmax of 6%, a Plt value of about 0.65 will be given.
C) 7%, the equipment is:
- someone looking after the use (eg hair dryer, vacuum cleaner, kitchen equipment such as a blender, gardening equipment such as lawn mowers, portable tools such as electric drills) or
- Automatic switch no more than 2 times a day or a switch intended to be manual, and after a power interruption, there is a delay to restart (delay not less than tens of seconds) or manually restart.
For devices that comply with 6.6 with several separate control circuits, there is only one delay to restart after a power interruption, limits b) and c) apply; for all devices that have an automatic switch that can be actuated immediately after a power interruption, Limits a) apply; for all manual switching devices, limits b) and c) apply depending on the frequency of the switch.
The Pat and Plt requirements do not apply to voltage changes caused by manual switches.
These limits are not suitable for emergency switching actions or emergency interruptions.
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