BSI PD IEC TS 62749:2020
$198.66
Assessment of power quality. Characteristics of electricity supplied by public networks
| Published By | Publication Date | Number of Pages |
| BSI | 2020 | 62 |
This Technical Specification specifies the expected characteristics of electricity at the point of supply of public low, medium and high voltage, 50 Hz or 60 Hz, networks, as well as power quality assessment methods.
NOTE 1 The boundaries between the various voltage levels can be different for different countries/regions. In the context of this TS, the following terms for system voltage are used:
low voltage (LV) refers to UN ≤ 1 kV;
medium voltage (MV) refers to 1 kV < UN ≤ 35 kV;
high voltage (HV) refers to 35 kV < UN ≤ 230 kV.
NOTE 2 Because of existing network structures, in some countries/regions, the boundary between medium and high voltage can be different.
This document applies to the phenomena listed in Table 1.
Table 1 – Classification of electromagnetic phenomena addressed by power quality indices
NOTE 3 Specification of related measurement methods can be found in IEC 61000-4-30.
NOTE 4 Specification of the performance of related measuring instruments can be found in IEC 62586.
While power quality is related to EMC in a number of ways, especially because compliance with power quality requirements depends on the control of cumulative effect of electromagnetic emission from all/multiple equipment and/or installations, this document is not an EMC publication (see also Annex F).
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 4 | CONTENTS |
| 7 | FOREWORD |
| 9 | INTRODUCTION |
| 10 | 1 Scope 2 Normative references Tables Table 1 – Classification of electromagnetic phenomena addressed by power quality indices |
| 11 | 3 Terms and definitions |
| 19 | 4 Recommended values for power quality indices 4.1 General |
| 21 | 4.2 Frequency deviation 4.3 Supply voltage deviation 4.3.1 General 4.3.2 Low voltage systems |
| 22 | 4.3.3 Medium voltage systems 4.3.4 High voltage systems 4.4 Voltage unbalance |
| 23 | 4.5 Flicker 4.6 Harmonic and interharmonic voltage 4.6.1 General 4.6.2 Low voltage systems Table 2 – Flicker severity Plt recommended values |
| 24 | 4.6.3 Medium voltage systems Table 3 – Recommended values of individual harmonic voltages at the low voltage points of supply for orders up to 50 given in percent of the fundamental voltage U1 |
| 25 | 4.6.4 High voltage systems Table 4 – Recommended values of individual harmonic voltages at the medium voltage points of supply for orders up to 50 given in percent of the fundamental voltage U1 |
| 26 | 4.7 Voltage dip Table 5 – Indicative values of individual harmonic voltages at the high voltage points of supply given in percent of the fundamental voltage U1 |
| 27 | 4.8 Voltage swell 4.9 Voltage interruption |
| 28 | 4.10 Mains communicating voltage 4.11 Rapid voltage change Figures Figure 1 – Mains communicating voltages recommended values in percent of UN used in public LV networks (or Uc in public MV networks) |
| 29 | 4.12 Transient overvoltage 4.12.1 Low voltage systems 4.12.2 Medium and high voltage systems 5 Objectives and methods for power quality assessment 5.1 General |
| 30 | 5.2 Site power quality assessment 5.2.1 General 5.2.2 Continuous phenomena |
| 31 | Table 6 – Site power quality assessment methods |
| 32 | 5.2.3 For discontinuous phenomena (single event) Figure 2 – Example for illustrating voltage THD assessment result trends Table 7 – Example of single event assessment |
| 33 | 5.3 System aspect power quality assessment 5.3.1 General 5.3.2 For continuous phenomena 5.3.3 For discontinuous phenomena (events) Figure 3 – Example showing information of single event assessment |
| 34 | Table 8 – List of individual events measured at a single monitoring site Table 9 – SARFI-X indices coming out of Table 8 |
| 35 | Table 10 – Magnitude-duration table format |
| 36 | Annexes Annex A (informative) Examples of profiles for power quality specification A.1 General A.2 LV and MV public distribution networks in European countries Table A.1 – Examples of profiles in European countries |
| 37 | A.3 LV, MV and HV power supply system in China Table A.2 – Examples of profiles in China |
| 38 | A.4 Example of a transmission system in Canada Table A.3 – Examples of profiles in Canada |
| 39 | A.5 Examples of profiles in Australia Table A.4 – Examples of profiles in Australia |
| 40 | Annex B (informative) Additional information on power quality assessments B.1 Weekly percentile values assessed on a daily sliding basis Figure B.1 – Comparison of two methods of assessing weekly 95th percentile values |
| 41 | B.2 Example on system aspect continuous disturbance evaluation B.3 Aggregation method used for events Table B.1 – Listing of system power quality evaluation |
| 42 | Figure B.2 – Example for illustrating the differences resultedby time aggregation method |
| 43 | Figure B.3 – Example of time sequence of voltage dips that can be aggregated in two different ways |
| 44 | Annex C (informative) Main impact of poor power quality C.1 General C.2 Harmonic distortion C.3 Voltage unbalance |
| 45 | C.4 Voltage deviation C.5 Frequency deviation C.6 Voltage fluctuation C.7 Flicker C.8 Voltage dip (or voltage sag) C.9 Transient overvoltages |
| 46 | Annex D (informative) Power quality issues related to distributed generation and micro-grids D.1 General D.2 Voltage deviation D.3 Harmonics D.4 DG magnetic bias (DC current injection) |
| 47 | D.5 Voltage fluctuation and flicker D.6 High frequency conducted disturbances |
| 48 | Annex E (informative) Methods to maintain and improve power quality E.1 General E.2 Voltage deviation E.3 Harmonics |
| 49 | E.4 Flicker E.5 Voltage unbalance |
| 50 | E.6 Voltage dip/swell/short time interruption |
| 51 | Annex F (informative) Relation between power quality and EMC F.1 General F.2 Differences between power quality and compatibility levels |
| 52 | F.3 Example of power quality level versus compatibility level Figure F.1 – Application points in a LV system (example) Figure F.2 – Relation between disturbance levels (schematic significance only) |
| 53 | Figure F.3 – Cumulative distribution of all THD values recorded at 30 points of supply of the LV system, during one week |
| 54 | Figure F.4 – Weekly 95th percentile THD values evaluated at each monitored LV point of supply |
| 55 | Annex G (informative) Other phenomena G.1 General G.2 Level behaviour over time G.3 Duration G.4 Periodicity |
| 56 | G.5 Bandwidth |
| 57 | Annex H (informative) Role of stakeholders for power quality management – Coordination of the parties involved H.1 General H.2 Network operator – Network user H.3 Network user – Equipment supplier |
| 58 | H.4 Network operator – Equipment supplier |
| 59 | Bibliography |
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BSI PD IEC TS 62749:2020
Assessment of power quality. Characteristics of electricity supplied by public networks Published By Publication Date…
