Description
This section of SZNS NRS 097-2 defines standards for the utility interface for the interconnection of small-scale embedded generation systems to a utility network.
This section of SZNS NRS 097-2 applies to embedded generators or embedded generator systems of nominal capacity less than 1000 kVA, connected to a single-phase, dual phase, or three-phase low voltage networks.
This section of SZNS NRS 097-2 aims to provide a practical specification for utilities to facilitate the incorporation of embedded generation on low-voltage networks while ensuring compliance of the utility interface with the requirements documented in this specification.
This document does not guarantee that the respective utilities will allow connection of the EG at the customer’s preferred location and current terms and conditions; additional requirements may be set by the utility to ensure safety and quality of supply on the network.
This part of NRS 097 does not look at or specify any requirements for the fuel source and or converters of alternate energy sources, i.e. it does not cover specifications for e.g. the following:
- PV panels or the installation thereof;
- fuel sources, e.g. fuel cells, biogas; and
- interfaces (mechanical, electrical or different) between the primary fuel source and the inverter or generator, e.g. batteries, gearbox, clutch etc.
The Grid Connection Code Requirements For Renewable Power Plants (RPPS) Connected To The Transmission System (TS) Or The Distribution System (DS) In South Africa version 2.8 wasapproved by NERSA and published in July 2014. The Grid Code documents are also dynamicdocuments that may change as requirements in the industry evolves, i.e. updated documents willbecome available at times and are published on the NERSA website.
The Grid Code defines the minimum requirements for any renewable power plant (embedded generator system) in order to connect to the grid or network. Wherever conflict exists between this set of documents and the applicable Grid Code(s) in terms of more strict requirements, the applicable Grid Code(s) will take preference.
- NOTE 1 The 1000 kVA value will be revisited and reviewed as the industry evolves.
- NOTE 2 This document provides a standard set of specifications for small embedded generators. Compliance with this document does not guarantee that a utility will or can allow connection to the utility network.
- NOTE 3 The customer is advised to contact the utility to discuss potential further connection requirements.
TABLE OF CONTENTS
| Content | Page |
| 1Scope | 1 |
| 2 Normative references | 1 |
| 3 Terms, definition and abbreviations | 2 |
| 3.1 Terms & definition | 2 |
| 3.2 Abbreviations | 2 |
| 4Requirements | 5 |
| 4.1 Utility Compatibility ( Perfomance aspects) | 5 |
| 4.2 Safety protection and control | 8 |
| 4.3 Metering | 11 |
| Appendix A Notes to purchase | 30 |
| Appendix B Earthing systems | 31 |
| Appendix C Network impedance | 40 |
| Appendix D (Annex A of VDE-AR-N 4105) | 42 |
| Appendix E ( Annex B of VDE -AR-N-4105) Connection examples | 52 |
| Appendix F (Annex C of VDE-AR-N-4105) Example of meter panel configuration | 60 |
| Appendix G Generation management network security management | 66 |
| Bibliography | 68 |