IEC TR 63282:2020

LVDC systems - Assessment of standard voltages and power quality requirements

IEC TR 63282:2020(E) collects information and reports experience in order to make recommendations for the standardization of voltage levels and related aspects (power quality, EMC, measurement …) for LVDC systems (systems with voltage level lower than 1 500 V d.c.).
Rationale for the proposed voltage values are given. Variation of parameters for the voltage (power quality) and recommendation 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

General Information

• Status: Published
• Publication Date: 26-Nov-2020
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: TC 8 - System aspects of electrical energy supply
• Drafting Committee: JWG 9 - TC 8/JWG 9

Relations

• Revised: IEC TR 63282:2024 - LVDC systems - Assessment of standard voltages and power quality requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TR 63282 ®
Edition 1.0 2020-11
TECHNICAL
REPORT
colour
inside
LVDC systems – Assessment of standard voltages and power quality
requirements
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IEC TR 63282 ®
Edition 1.0 2020-11
TECHNICAL
REPORT
colour
inside
LVDC systems – Assessment of standard voltages and power quality

requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020 ISBN 978-2-8322-9078-1

– 2 – IEC TR 63282:2020 © IEC 2020
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Structure of LVDC systems . 12
4.1 General . 12
4.2 Architecture . 12
4.3 Operation modes . 13
4.3.1 Passive DC systems . 13
4.3.2 Active DC systems . 13
5 LVDC voltage division. 13
5.1 General . 13
5.2 Voltage bands . 14
5.3 Operation ranges with respect to DC voltage and time . 15
5.4 States . 16
6 Power quality phenomena relevant to LVDC networks . 17
6.1 General . 17
6.2 Relationships between voltage band and power quality in LVDC systems . 17
6.3 Supply voltage deviation . 18
6.4 Ripple and high frequency noise . 19
6.5 Voltage swell . 20
6.6 Voltage dip . 21
6.7 Voltage supply interruption. 22
6.8 Rapid voltage change (RVC) . 22
6.9 Voltage surges . 23
6.10 Voltage unbalance . 24
7 Recommendations . 25
7.1 General . 25
7.2 Recommended voltages . 25
7.3 EMC and compatibility levels . 26
7.4 Power quality recommendations . 28
7.5 Measurement methods . 29
7.5.1 General . 29
7.5.2 DC system RMS value integration time . 29
7.5.3 DC power quality measurement methods . 29
Annex A (informative) PQ waveforms collected from a certain LVDC project . 30
Annex B (informative) Load distance in DC distribution systems . 32
Annex C (informative) Electric power and power quality computation in DC systems . 33
C.1 DC RMS value of voltage or current . 33
C.2 General electric power system: decomposition of a general electric load . 33
C.3 Computation of electric powers and PQ indices. 34
C.4 Representation of electric powers in AC system . 37
C.5 Representation of electric powers in DC system . 37
C.6 Power quality indices in DC system. 38
C.7 Illustration example of deformation power in DC system . 39

C.8 Main conclusions on electric value computation in DC systems . 40
C.9 Need of characteristics of DC voltage . 41
Annex D (informative) District LVDC system demonstration project in Tongli, China . 42
D.1 Project overview . 42
D.2 Voltage level selection principle . 42
D.3 System operation . 43
Annex E (informative) An office building with general building utilities and office work
places . 44
Annex F (informative) An example of configurations for active DC systems . 50
F.1 General . 50
F.2 Structure . 50
F.3 State of grid (SOG) . 50
Annex G (informative) Preferred voltage in different countries . 55
G.1 Preferred voltage in China . 55
G.2 Preferred voltage in the Netherlands . 57
G.3 Preferred voltage in Germany . 58
Annex H (informative) Voltage with respect to earth . 59
Annex I (informative) CIGRE approaches for DC systems . 62
Bibliography . 63

Figure 1 – Unipolar, balanced and bipolar DC systems . 12
Figure 2 – Voltage bands in DC systems . 14
Figure 3 – DC Voltage areas for safe interoperability . 15
Figure 4 – Relationships between voltage band and power quality in LVDC systems . 18
Figure 5 – Voltage swell example. 20
Figure 6 – Voltage dip example . 21
Figure 7 – RVC event: example of a change in average voltage that results in an RVC
event . 23
Figure 8 – Example of voltage surge . 24
Figure 9 – A schematic of a bipolar system (the CIGRE B4 DC test system) . 25
Figure 10 – Relation between disturbance levels (schematic significance only) . 26
Figure 11 – LVAC voltage compatibility and immunity levels . 27
Figure A.1 – Voltage deviation caused by load switching . 30
Figure A.2 – Voltage ripple in steady state . 30
Figure A.3 – Voltage dip caused by the start-up of motor load . 31
Figure C.1 – Equivalent model of a general electric load . 34
Figure C.2 – Representation of electric powers in AC system . 37
Figure C.3 – Representation of electric powers in DC system . 37
Figure C.4 – Ripples . 38
Figure C.5 – DC powers . 40
Figure C.6 – Compatibility level measured in differential mode values . 41
Figure D.1 – Architecture of the district LVDC system in Tongli . 42
Figure E.1 – Office building with general building utilities and office work places . 44
Figure E.2 – Overview of DC-zones for DC system . 46
Figure F.1 – Active DC distribution system . 50

– 4 – IEC TR 63282:2020 © IEC 2020
Figure F.2 – DC distribution system with one load and one source . 52
Figure F.3 – DC distribution system with more than one load and a source and
increasing source power . 53
Figure F.4 – Distribution system with more than one load and a source and DUMP
LOAD active . 53
Figure F.5 – Distribution system with more than one load and source in overloaded
mode . 54
Figure H.1 – DC voltage definitions .
...