MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C Distribution Capability Statement [2018 – 2020] MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C Preface This Distribution Capability Statement is provided by the Muscat Electricity Distribution Company (hereafter MEDC) according to Distribution and Supply Licence Condition number 32 and in accordance to the Distribution Planning code 4.4. This Statement describes the Distribution System capability over the next three years 2018 -2020. The Statement provides up-to-date Distribution System data to provide customers with the information needed to identify those parts of the system which offer the most suitable opportunities for future connections to the MEDC system and where constraints currently exist, or will exist. This year we have taken the decision to further provide detailed system data in spreadsheet format. The spreadsheet supplements this capability statement and is available to customers and other relevant stakeholders. We hope this provides our customers and other stakeholders with a transparent and usable platform to assess possible points of connection within the MEDC licenced area and to assess the opportunities it provides. The board of MEDC has determined this three-year plan to clarify and highlight MEDC’s key priorities over the coming years. The plan will form the basis for the company’s further investments and serve to confirm MEDC’s contributions to the Omani electricity sector. Eng. Abdullah Bin Said Al Badri MEDC CEO MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C CONTENTS 4.8. CONTINUOUS IMPROVEMENT AREAS 18 LIST OF TABLES 2 Bulk Load Details and Modelling 18 33/11.5kV Transformers Tap Changer LIST OF FIGURES 2 Modelling 18 11kV System Modelling 19 1. INTRODUCTION 1 Improved and Updated Motoric Short Circuit 1.1. PURPOSE OF THE STATEMENT 1 Contribution 19 1.2. STRUCTURE OF THIS CAPABILITY STATEMENT 1 Technical Losses Calculation using Power System Models 19 2. PLANNING PHILOSOPHIES AND PRACTICES Maximum and Minimum Scenario Modelling 19 2 2.1. OBLIGATIONS OF THE DISTRIBUTION LICENCE 2 5. CHALLENGES AND OPPORTUNITIES 2.2. REQUIREMENTS OF THE DISTRIBUTION CODE 2 WITHIN THE SYSTEM 20 2.3. DISTRIBUTION SYSTEM SECURITY STANDARDS 2 5.1. NEW CONNECTION APPLICATIONS 20 2.4. SYSTEM VOLTAGES AND CONFIGURATION 3 5.2. SYSTEM CONSTRAINTS AND OPPORTUNITIES 20 2.5. FREQUENCY DEVIATIONS 4 2.6. VOLTAGE WAVEFORM QUALITY 4 6. THE INVESTMENT PLAN 23 2.7. VOLTAGE FLUCTUATIONS 4 6.1. SYSTEM DEVELOPMENT PROJECTS DURING THE 2.8. AUTO-RECLOSING AND SINGLE PHASE PROTECTION PERIOD 2018– 2020 23 OPERATION 4 Zone 1 – (The Eastern Zone) 26 2.9. DESIGN FAULT LEVELS 4 Zone 2 - (The Central Zone) 28 2.10. STANDARD EQUIPMENT SIZES 5 Zone 3 - (The Western Zone) 30 Conductors 5 Transformers 5 Appendix A: Distribution System Capability Switchgear 5 Statement 32 Capacitors 5 Appendix B: DSSS Non Compliances 33 2.11. TECHNICAL STANDARDS 6 2.12. SPECIFICATION OF APPARATUS AND PLANT 6 Appendix C: System Studies Results 35 2.13. EARTHING 6 2.14. VOLTAGE REGULATION AND CONTROL 6 2.15. PROTECTION 6 3. PLANNING DRIVERS 8 3.1. BACKGROUND 8 3.2. ZONE 1 – (THE EASTERN ZONE) 8 3.3. ZONE 2 - (THE CENTRAL ZONE) 8 3.4. ZONE 3 - (THE WESTERN ZONE) 8 4. MEDC DISTRIBUTION SYSTEM 10 4.1. EXISTING DISTRIBUTION SYSTEM 10 4.2. AREA BASED SYSTEM HISTORICAL GROWTH 10 4.3. SYSTEM DEMAND AND LOAD DURATION 11 4.4. SYSTEM DEMAND FORECAST 12 Best Practice Distribution Load Forecasting 12 System Demand Growth 13 4.5. GRID SUPPLY POINTS 13 4.6. DISTRIBUTION SYSTEM ANALYSIS 17 Load Flow Analysis 17 Short Circuit Analysis 17 4.7. TECHNICAL LOSSES 18 MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C LIST OF TABLES LIST OF FIGURES Table 1 DSSS Classifications and Defined Restoration Times . 3 Figure 1 MEDC Distribution System ....................................... 9 Table 2 System Nominal Voltages and Tolerance .................. 4 Figure 2 Hourly Demand – Summer Maximum Day Profile 2010 -2017 ........................................................................... 11 Table 3 Short Circuit Rating of Switchgear ............................. 5 Figure 3 2017 Load Duration Curve ..................................... 12 Table 4 Standard 33kV conductor Sizes and Ratings .............. 5 Figure 4 System Historical and Forecast Maximum Demand Table 5 Standard 11kV conductor Sizes and Ratings .............. 5 (2006-2020) ......................................................................... 14 Table 6 Standard Switchgear Ratings ..................................... 5 Figure 5 33kV Existing System (2017) .................................. 15 Table 7 Summary of Installed and Firm Capacity of MEDC Figure 6 33kV Expected System Development (2018 to 2020) Distribution System – 2017 [up to July 2017] ...................... 10 ............................................................................................. 16 Table 8 Area Wise Compound Annual Growth Rate [CAGR] of MEDC Distribution System ................................................... 10 Table 9 System Maximum and Minimum Demand in 2017 . 11 Table 10 The CAGR System Load Growth% from 2010 to 2017 ............................................................................................. 13 Table 11 MEDC System Maximum Demand in MW [Historical and Forecast] ....................................................................... 14 Table 12 MEDC System Technical Losses ............................. 18 Table 13 New 11kV and LV Customer Applications .............. 20 Table 14 2020 Projected Capacity Constraints in MVA ........ 22 Table 15 Status of the Primary Substations at a glance [2018- 2020] .................................................................................... 23 Table 16 Summary of Sponsored Projects ........................... 23 Table 17 Summary of Planned Projects in MEDC Distribution System to meet Summer 2018 Maximum Demand ............. 24 Table 18 Summary of Planned Projects in MEDC Distribution System to meet Summer 2019 Maximum Demand ............. 25 Table 19 Summary of Planned Projects in MEDC Distribution System to meet Summer 2020 Maximum Demand ............. 26 MEDC Distribution Capability Statement (2018-2020) – V2.2 2 MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C 1. INTRODUCTION 1.1. Purpose of the Statement Oman Electricity Transmission Company (OETC), has This Capability Statement is intended to provide an been fully assessed in the development of MEDC’s understanding of MEDC’s 33kV and 11kV Distribution development plans. Where appropriate 33kV load System and to present MEDC’s development plans for transfers from one 132/33kV grid station (GSS) to the 33kV and 11kV Distribution System for the years another have been considered and where this option is 2018-2020. This Statement includes electrical data for not feasible applications for additional 132/33kV GSS the station loads, overhead lines, cable circuits, capacity have been submitted to OETC, resulting in transformers, switchgear and capacitors used in the OETC plans to construct and build additional 132/33kV preparation of Distribution System models for the GSS capacity within the MEDC licence area. power system studies and form the MEDC Distribution 1.2. Structure of this Capability Statement System. The results of the load flow and short circuit Chapter 2 and Chapter 3 provide relevant information studies are presented thereby providing an assessment associated with MEDC’s licence obligations, planning of the capability of the Distribution System. assumptions and technical standards. Chapter 4 The schedule of committed and planned system provides an overview of the Distribution System, development projects on the 33kV Distribution System together with details of the demand profile, projected is presented in Chapter 6. Implementation of these demand forecast, system constraints and a summary of system development projects is necessary to meet the technical analysis of the Distribution System. future forecast demand growth, maintain or improve Chapter 5 summarises the current levels of connection the capability in the Distribution System to meet the activity within the MEDC system and provides an system growth and to address the issues of actual or overview of the opportunities new customers may forecast non-compliance with the Distribution System have whilst identifying the challenges that MEDC face Security Standards (DSSS). Implementation of these currently along with measures to address them. projects will increase the number of 33/11kV primary substations(PSS) providing enhanced opportunities for Chapter 6 provides detail of the development projects new and increased customer connections. proposed over the three-year period 2018 to 2020. The impact of MEDC’s forecast demand growth and Appendices detail the results of the required Distribution System development projects on the distribution system analysis studies. Transmission System, which is owned and operated by MEDC Distribution Capability Statement (2018-2020) – V2.2 1 MUSCAT ELECTRICITY DISTRIBUTION COMPANY S.A.O.C 2. PLANNING PHILOSOP HIES AND PRACTICES MEDC recognise that it is fundamental to provide Licence Condition 32 also describes the further sufficient guidance to enable relevant stakeholders and information that needs to be included within the current and potential customers to understand the Capability Statement relating to: quality of supply that they may receive from the • Information on the status of the Distribution Distribution System and to enable