This standard specifies the limits and test, calculation and evaluation methods for voltage fluctuation and flicker. This standard applies to the rapid changes in voltage at the common connection point caused by fluctuating loads in the normal operation of the AC 50Hz power system, and the occasions where people may feel the flicker of lights. GB 12326-2000 Power Quality Voltage Fluctuation and Flicker GB12326-2000 Standard Download Decompression Password: www.bzxz.net

GB 12326—2000
This standard is one of the power quality standards. The national standards for power quality that have been formulated and promulgated include: Permissible deviation of supply voltage (GB12325—1990): Permissible voltage fluctuation and flicker (GB12326—1990): Spectrum wave of public power grid (GB/T14549—1993): Permissible unbalance of three-phase voltage (GB/T15543-1995) and Permissible deviation of power system load (GB/T15945-1995.
This standard refers to the electromagnetic compatibility (EMC) standard of the International Electrotechnical Commission (IEC) IEC 61000-3-7, etc. (see references), comprehensively revised the national standard GB12326-1990. Compared with GB12326-1990, the main contents of this revision are: 1) the system voltage is divided into high voltage (HV), medium voltage (MV) and low voltage (LV), and the relevant limits are respectively stipulated, as well as the allocation of user indicators:
2) the flicker indicator in the national standard is changed from citing Japan's △Vi to IEC's short-time flicker Pt and long-time flicker Pr indicators, so as to be in line with international standards and in line with China's national conditions
3) the voltage fluctuation (variation) limit is associated with the frequency of change, so that the standard's provisions on this indicator are more relevant The interference effect of actual fluctuating load on the power grid:
4) The original standard, which was mainly based on voltage fluctuation (variation), was changed to mainly based on flicker value (the △V in the original standard is the recommended value), to correspond to the international standard:
5) The flicker allowable index of a single user is allocated according to the proportion of its agreed capacity to the total power supply capacity, and is divided into three levels according to the amount of interference generated and the system situation (this content was not included in the original standard), which makes the index allocation more reasonable and convenient for actual implementation: 6) The calculation formulas for flicker superposition and transmission, the method for determining the power supply load in the high-voltage system, the calculation of voltage changes and the evaluation of flicker are introduced, and some typical case analyses are given; 7) The flicker measuring instrument specified in IEC 61000-4-15 is introduced and included as Appendix A of the standard to facilitate the unification of measuring instruments; 8) The entire standard is written in accordance with the relevant provisions of the national standards GB/T 1.1 and GB/T 1.2. The leading element of the original standard name, Power Quality, was translated into English as "Power quality of electric energy guffly" and changed to the internationally used "Power quality", and the name of this standard was changed to "Power quality voltage fluctuation and flicker". As an electromagnetic compatibility (EMC) standard, IEC 61000-3-7 and other standards involve relatively more content, and the discussion is not concise enough. In the revision of the national standard, relevant content was selected, and the explanation of the overview and principle was basically deleted, because the country will successively release EMC series standards equivalent to IEC 61000, which can be used as a reference for the implementation of the national standard for power quality. For some definitions, symbols and abbreviations required in the national standard, as well as the relevant flicker measurement instrument specifications and the expression of flicker (P), IEC61000-3-3 and IEC61000-4-15 are mainly referred to. It should be pointed out that in adopting the relevant contents of IEC61000, this standard has made modifications to the following points: 1) According to the IEC standard, for flicker Psl and Pi indicators, the evaluation and measurement time is at least one week, and the maximum value with 99% probability is used for measurement. Such regulations are actually difficult to implement in power grids. This standard stipulates that the flicker indicator is measured for 1 day (24 hours) and the maximum value with 95% probability is used for measurement; for household indicators, in principle, it is stipulated that they shall not exceed the standard. 2) For voltage fluctuations, in addition to giving the limit value according to the frequency range of fluctuations, the limit value of random and irregular voltage fluctuations and the measurement and value-taking methods are also supplemented.
3) In the IEC standard, in addition to the electromagnetic compatibility value, the "planning value" is also introduced. The planning value is not greater than the compatible value in principle. It is the target value set by the power department according to the characteristics of load and power structure. This standard does not adopt "compatible value" or "planning value", and uses the concept of "limit value" all the time.
4) IEC61000-3-7 actually only stipulates the compatibility limit of medium and high voltage fluctuating loads. For low voltage, it mainly controls the limit of a single GB12326--2000
device, which has been stipulated in IEC 61000-3-3 and IEC 61000-3-5. (There will be equivalent standards in China). When formulating this standard, considering that the compatibility values ​​of medium and low voltage equipment are the same (see IEC6100U-3-7), and most domestic low voltage electrical equipment has not been tested for its voltage passive and flicker indicators according to IEC standards, low voltage is also stipulated to make the standard more complete. This standard will replace GB12326-1990 from the date of implementation. Appendix A and Appendix B of this standard are both standard appendices. Appendix C and Appendix D of this standard are both suggestive appendices. This standard is proposed by the Electric Power Department of the State Economic and Trade Commission. This standard is under the jurisdiction of the National Technical Committee for Standardization of Voltage, Current and Frequency. This standard was drafted by: State Grid Corporation Electric Power Research Institute, Tsinghua University, Beijing Power Supply Bureau, Beijing Iron and Steel Design and Research Institute, Mechanical Science Research Institute.
The main drafters of this standard are: Lin Haixue, Sun Shuqin, Zhao Gang, Chen Binfa, Wang Jingyi, Li Shilin. 1 Scope
National Standard of the People's Republic of China
Power qualitywww.bzxz.net
Voltage fluctuation and flicker
Power guality -Voltage fluctuatlon and flicker This standard specifies the limits and test, calculation and evaluation methods of voltage fluctuation and flicker. GB12326—2000
Replaces GB12326—1990
This standard applies to the rapid change of voltage at the common connection point caused by fluctuating load in the normal operation of the AC 50Hz power system and the occasions where the flashing of lights may be noticeable to people. 2 Referenced Standards
GR156--1993 Standard Voltage
3 Definitions
This standard adopts the following definitions:
3.1 Point of common connection (PCC) The connection point of more than one user in the power system. 3.2 Fluctuating load
A load that takes rapidly changing power from the power supply network during production (or operation). For example: steelmaking arc furnace, rolling mill, arc welding machine, etc. 3.3 RMS voltage shape U(t) RMS voltage shape, U(t) The time function of the RMS value (r. tm. s.) of each half fundamental voltage cycle. 3.4 Voltage change characteristic d(t) relative voltage change characteristic, d(t) The time function of the voltage root mean square value change, expressed as a percentage of the system nominal voltage. 3.5 Voltage change d relative voltage change, d The difference between two adjacent extreme voltages on the voltage change characteristic d(t). 3.6 Rate of occurrence of voltage changes The number of voltage changes per unit time (the voltage changes from large to small or from small to large, each change is counted as one change). If there are ten changes in the same direction, if the interval is less than 30 ms, it is counted as one change. 3.7 Flicker time t Flicker time, t A value with a time dimension that represents the flicker effect of voltage change, which is related to the waveform, amplitude and frequency. 3.8 Voltage fluctuation voltage fluctuation A series of changes or continuous changes in the voltage root mean square value. 3.9 Flicker
The visual sensation caused by unstable lighting illumination.
3.10 Flicker meter
A special instrument for measuring flicker (see Appendix A). Note i General measurement P and Pr
Approved by the State Administration of Quality and Technical Supervision on April 3, 2000 and implemented on December 1, 2000
GB12326-2000
3.11 Short term flicker value Pshort term Beverity, P, is a statistical value for measuring the intensity of flicker in a short time (if minutes) (see Appendix A). P=1 is the usual limit value for visual stimulation caused by flicker.
3.2 Long term flicker value Pulong term severity, Pl is calculated from the short term flicker value P. It reflects the value of flicker intensity for a long time (several hours) (see Appendix A). 3.13 Cumulative probability function (CPF) The horizontal axis represents the measured value (such as instantaneous flicker value), and the vertical axis represents the percentage of the time that exceeds the corresponding horizontal axis value in the entire measurement time (see Figure A2).
4 Limits of voltage fluctuation and flicker
4.1 The voltage fluctuation limits and fluctuation frequencies caused by fluctuating loads at the common connection point of the power system are related to the voltage level, see Table 1. Table 1 Voltage fluctuation limits
10≤100
1001000
LV, MV
1 For very small fluctuation frequencies (less than once a day), the voltage fluctuation limit d can be relaxed, but it is not specified in this standard. 2 For random and irregular voltage fluctuations, the values ​​marked with "*" in the table are the limits based on the 95% probability maximum value. 3 The system nominal voltage U level in this standard is divided into the following categories: Low voltage (LV)
Medium voltage (MV)
High voltage (HV)
Uyslky
1 kv
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.