Electromagnetic compatibility (EMC)—Limits—Limitation of voltage changes,voltage fluctuations and flicker in public low-voltage supply systems,for equipment with rated current ≤16 A pe
1 Scope
This part is concerned with the limitation of voltage fluctuations and flicker impressed on the public low-voltage system.
This part specifies limits of voltage changes which may be produced by an equipment tested under specified conditions and gives guidance on methods of assessment.
This part is applicable to electrical and electronic equipment having an input current equal to or less than 16 A per phase, intended to be connected to public low-voltage distribution systems of between 220 V and 250 V line to neutral at 50 Hz, and not subject to conditional connection.
Equipment which does not comply with the limits of this part when tested with the reference impedance Zref of 6.4, and which therefore cannot be declared compliant with this part, may be retested or evaluated to show conformity with IEC 61000-3-11. IEC 61000-3-11 is applicable to equipment with rated input current ≤75 A per phase and subject to conditional connection.
The tests according to this part are type tests. Particular test conditions are given in Appendix A and the test circuit is shown in figure 1.
Note: The limits in this part are based mainly on the subjective severity of flicker imposed on the light from 230 V/60 W coiled-coil filament lamps by fluctuations of the supply voltage. For systems with nominal voltage less than 220 V line to neutral and/or frequency of 60 Hz, the limits and reference circuit values are under consideration.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this part. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 4365-2003 Electrotechnical terminology — Electromagnetic compatibility (IEC 60050(161):1990, IDT)
GB 4706.20-2004 Household and similar electrical appliances — Safety Particular requirements for tumble dryers (IEC 60335-2-11:2002, IDT)
GB 15579.1-2004 Arc welding equipment — Part 1:Welding power source (IEC 60974-1:2000, IDT)
GB 17625.1-2003 Electromagnetic compatibility — Limits — Limits for harmonic current emissions (equipment input current≤16A per phase) (IEC 61000-3-2:2001, IDT)
GB 17625.3-2000 Electromagnetic compatibility — Limits — Limitation of voltage fluctuations and flicker in low-voltage power supply systems for equipment with rated current greater than 16A (idt IEC 61000-3-5:1994)
IEC 60725:1981 Considerations on reference impedances for use in determining the disturbance characteristics of household appliances and similar electrical equipment
IEC 61000-3-11 Electromagnetic compatibility (EMC) — Part 3-11: Limits — Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems — Equipment with rated current ≤75 A and subject to conditional connection
IEC 61000-4-15:2003 Electromagnetic compatibility (EMC) — Part 4-15: Testing and measurement techniques — Flickermeter — Functional and design specifications
3 Terms and Definitions
For the purpose of this part, terms and definitions given in GB/T 4365-2003 and the following apply.
3.1
r.m.s. voltage shape
U(t)
The time function of r.m.s. voltage, evaluated as a single value for each successive half period between zero-crossings of the source voltage (see Figure 2).
3.2
Voltage change characteristic
∆U(t)
The time function of the r.m.s. voltage change evaluated as a single value for each successive half period between zero-crossings of the source voltage between time intervals in which the voltage is in a steady-state condition for at least 1 s (see Figure 2).
Note: Since this characteristic is only used for assessments using calculations, the voltage in the steady-state condition is assumed to be constant within the measurement accuracy (see 6.2).
3.3
Maximum voltage change characteristic
∆Umax
The difference between maximum and minimum r.m.s. values of a voltage change characteristic (see Figure 2).
3.4
Steady-state voltage change
∆Uc
The difference between two adjacent steady-state voltages separated by at least one voltage change characteristic (see Figure 2).
Note: Definitions 3.2 to 3.4 relate to absolute phase-to-neutral voltages. The ratios of these magnitudes to the phase-to-neutral value of the nominal voltage (Un) of the reference network in figure 1 are called:
— relative voltage change characteristic: d(t) (definition 3.2);
— maximum relative voltage change: dmax (definition 3.3);
— relative steady-state voltage change: dc (definition 3.4).
These definitions are explained by the example in Figure 3.
3.5
Voltage fluctuation
Contents
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 Assessment of Voltage Changes, Voltage Fluctuations and Flicker
4.1 Assessment of a relative voltage change, "d"
4.2 Assessment of the short-term flicker value, Pst
4.3 Assessment of long-term flicker value, Plt
5 Limits
6 Test Conditions
6.1 General
6.2 Measurement accuracy
6.3 Test supply voltage
6.4 Reference impedance
6.5 Observation period
6.6 General test conditions
Appendix A (Normative) Application of Limits and Type Test Conditions for Specific Equipment
Appendix B (Normative) Test Conditions and Procedures for Measuring dmax Voltage Changes Caused by Manual Switching
Figure 1 Reference Network for Single-phase and Three-phase Supplies Derived from a Three-phase, Four-wire Supply
Figure 2 Histogram Evaluation of U(t)
Figure 3 Relative Voltage Change Characteristic
Figure 4 Curve for Pst=1 for Rectangular Equidistant Voltage Changes
Figure 5 Shape Factors F for Double-step and Ramp-voltage Characteristics
Figure 6 Shape Factors F for Rectangular and Triangular Voltage Characteristics
Figure 7 Shape Factor F for Motor-start Voltage Characteristics Having Various Front Times
Table 1 Assessment Method
Table A.1 Electrode Parameters
Table A.2 Frequency Factor R Related to Repetition Rate "r"
