IEC TR 63282:2024
(Main)LVDC systems - Assessment of standard voltages and power quality requirements
LVDC systems - Assessment of standard voltages and power quality requirements
IEC TR 63282:2024, which is a technical report, collects information and report experience for the standardization of voltage levels and related aspects (power quality, EMC, measurement, etc.) for LVDC systems (systems with nominal voltage up to and including 1 500 V DC).
Rationale for the proposed voltage values is given. Variation of parameters for the voltage (power quality) for their boundaries are defined. Nevertheless, some of the technical items are not exhaustively explained in this document and some gaps are identified for future work.
Attention is paid to the definition of DC voltage.
Systems in which a unipolar voltage is interrupted periodically for certain purposes, e.g. pulse voltage, are not considered.
Traction systems are excluded from this document.
This document gives technical inputs to TCs in charge of the standardization of different issues and coordinated by SyC LVDC.
This second edition cancels and replaces the first edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Optimized terms and definitions in Clause 3: DC system nominal voltage is modified. Oscillation is added. Active distribution system, passive distribution system are deleted.
b) Modified the definition of voltage bands: In Clause 5, the definition of voltage limits in voltage bands is added, from U1 to U6. The definition of voltage bands, from B4 to B7, is modified.
c) Distinguished the difference between oscillation and power quality phenomenon: In Clause 3, the definition of oscillation is added based on IEV 103-05-04. In 6.3, relationship between oscillation and power quality is clarified. Annex B gives a LDC oscillation typical example which has really happened in a MV&LVDC system in China.
d) Modified the recommended voltage for distribution DC network: The factors considered in voltage values definition is clarified. And the voltage is divided in two domains, distribution domain and installation domain. The voltage recommendation in LVDC is listed corresponding to voltage bands.
e) Modified the voltage immunity level assessment: It is mentioned in 7.2 that the assessment of voltage immunity levels of mass LVDC power electronic devices need to be further discussed, ripple as an example is introduced.
f) Added DC power quality measurement methods: In 7.3, DC power quality measurement methods is introduced based on AC methodologies. And some additional DC power quality indices are recommended to assess the DC system. DC electric power and power quality measurement methods are introduced in 7.4, defining the electric value integration time and frequency ranges. Typical electric power and power quality computation methods are modified in Annex D.
g) Added an annex on MVDC system: A use case of a typical MV&LVDC distribution system is added in Annex F, to support developments of TS of 8A and 8B on DC microgrids.
h) Added an annex on CurrentOS voltage level: The voltage level applied in CurrentOS is introduced in Annex L to give more information on the LVDC voltage level recommendation.
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Standards Content (Sample)
IEC TR 63282 ®
Edition 2.0 2024-08
TECHNICAL
REPORT
LVDC systems – Assessment of standard voltages and power quality
requirements
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IEC TR 63282 ®
Edition 2.0 2024-08
TECHNICAL
REPORT
LVDC systems – Assessment of standard voltages and power quality
requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020 ISBN 978-2-8322-9130-6
– 2 – IEC TR 63282:2024 © IEC 2024
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 10
4 Structure of LVDC systems . 14
4.1 General . 14
4.2 Architecture . 14
4.3 Operation modes . 15
4.3.1 Passive DC systems . 15
4.3.2 Active DC systems. 15
5 LVDC voltage division . 16
5.1 General . 16
5.2 Voltage bands . 16
5.3 Operation ranges with respect to DC voltage and time . 18
5.4 States . 19
6 Power quality phenomena relevant to LVDC networks . 19
6.1 General . 19
6.2 Relationships between voltage band and power quality in LVDC systems . 20
6.3 Relationship between oscillation and power quality in LVDC systems . 20
6.4 Supply voltage deviation . 21
6.5 Ripple and high frequency interference . 22
6.6 Voltage swell . 23
6.7 Voltage dip . 24
6.8 Voltage supply interruption . 25
6.9 Rapid voltage change (RVC) . 25
6.10 Voltage surges . 26
6.11 Voltage unbalance . 27
7 Guidance for voltages and power quality in LVDC system. 28
7.1 Considerations for voltages in distribution DC networks . 28
7.1.1 General . 28
7.1.2 Factors considered to define voltage values . 28
7.1.3 DC voltages . 30
7.2 EMC, compatibility and testing of equipment . 31
7.3 Considerations for DC power quality . 33
7.4 Measurement methods . 34
7.4.1 General . 34
7.4.2 DC system electric value integration time . 35
7.4.3 Frequency ranges of ripple spectral analysis . 35
7.4.4 DC power quality measurement methods . 35
7.4.5 DC system electric power measurements . 35
7.5 DC power quality standardization framework . 35
Annex A (informative) PQ waveforms collected from a certain LVDC project . 36
Annex B (informative) A LVDC oscillation typical example . 38
Annex C (informative) Supply radius in DC distribution systems . 40
Annex D (informative) Electric power and power quality computation in DC system . 41
D.1 DC mean and RMS values of voltage or current . 41
D.2 General electric power system: decomposition of a general electric load . 41
D.3 Computation of electric powers and PQ indices . 42
D.3.1 Computation of electric values in time domain . 42
D.3.2 Computation of electric values in frequency domain . 43
D.3.3 Total harmonic distortion T used in AC system . 44
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D.3.4 The relation of different electric powers . 45
D.4 Representation of electric powers in AC system . 46
D.5 Representation of electric powers in DC system . 46
D.6 Power quality indices in DC system . 47
D.6.1 General . 47
D.6.2 DC peak-peak ripples . 47
D.6.3 Ripple spectra . 47
D.6.4 DC RMS ripple or ripple distortion. 48
D.7 Illustration example of distortion power in DC system . 50
D.8 Main conclusions on electric value computation in DC system . 50
D.9 Need of characteristics of DC voltage . 51
Annex E (informative) District LVDC system demonstration project in Tongli, China. 52
E.1 Project overview . 52
E.2 Voltage level selection principle . 52
E.3 System operation . 53
Annex F (informative) A typical MV&LVDC distribution system in Wujiang, China . 54
F.1 Project overview . 54
F.2 Voltage selection . 55
Annex G (informative) An office building with general building utilities and office
workplaces . 58
G.1 Sustainable circular building . 58
G.2 Zone system . 61
G.3 Aspects regarding the DC zone classification in DC installation . 67
Annex H (informative) An example of configurations for active DC systems . 68
H.1 General . 68
H.2 Structure . 68
H.3 State of grid (SOG) . 68
Annex I (informative) Preferred voltage in different countries . 73
I.1 Preferred voltage in China . 73
I.2 Preferred voltage in the Netherlands . 75
I.3 Preferred voltage in Germany . 75
Annex J (informative) Voltage with respect to earth . 77
Annex K (informative) CIGRE approaches for DC systems . 80
Annex L (informative) Voltage level in Current OS . 81
L.1 Introduction to the organization . 81
L.2 Voltages used in Current OS . 81
Annex M (informative) Voltage level in DC-INDUSTRY and open DC alliance . 85
M.1 General . 85
M.2 Operating range of the components . 85
M.3 Regulated feeders . 86
M.4 Uncontrolled feeders . 86
M.5 Typical DC loads . 86
– 4 – IEC TR 63282:2024 © IEC 2024
M.6 Converters for energy storage or photovoltaic . 87
M.7 DC breakers . 87
M.8 Nominal voltage . 87
M.9 Voltage bands and limits . 87
M.10 Operating status of the DC grid .
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