Alex Rojas March 2015 IMPORTANCE OF ADVANCED MICROGRID CONTROL FUNCTIONALITY ON MICROGRID DESIGN Energy Management Division Siemens Corporation
Large Network vs. Islanded Grid Energy Flow Typical Large Network Energy Chain: Centralized, unidirectional grid Reality of Islanded Grid: Distributed energy and bidirectional energy flow Hydrogen Storage Diesel Generator Biogas CHP Private Solar Offshore Wind Parks Small Industrial Gas Turbine Pumped Storage Power Plant Storage Solutions Storage Solutions Electrical Vehicles Smart Street Lighting Large Scale PV Plant Unidirectional Power Flow Bidirectional Power Flow Page 2
Islanded Grid Electrical Infrastructure Microgrid Controller 2-69 kv open Page 3
Electrical Infrastructure to be Monitored or Controlled in Islanded Grid Diverse Generation Assets Wind, Solar, other RES GT, CHP, Fuel Cell, Diesel Gen-sets Battery, UPS, Other ESS Diverse Load Types Intermittent loads from industrial sites Sheddable vs. Non-Sheddable Loads Critical vs. Non-Critical Complex Modes of Operations Generation portfolio optimization (based on cost, or emissions or both) Black start Page 4
Operational Challenges in an Islanded Grid Challenge Voltage Stability Frequency Stability Weak System Inertia (compounded by the modest sum of spinning mass) Advanced Monitoring and Control Monitor and control VAR injection/absorption Dispatch Capacitor/Inductor Banks Dispatch Inverters with VAR capability Monitor and Control Voltage Regulators (distribution autotransformers) Monitor and control WATT injection/absorption Dispatch Energy Storage (WATTS) Ramp-up Generator Governors Dispatch Demand Response Assets (based on WATTS) Optimize the best combination of as many synchronous generators (and motors) connected and spinning Forecast availability of power from renewable gen resource Set the optimum level of charge (full, mid, low) for the storage unit Wind Biomass Photovoltaic Storage Page 5
Operational Challenges in an Islanded Grid (cont.) Managed Load Challenge Spinning Reserve (need increased by Intermittency From Renewable Gens) Advanced Monitoring and Control Microgrid Controller Platform will: Monitor and Dispatch Generation Monitor and Dispatch Load Monitor and Dispatch Energy Storage Forecast Energy Available from Renewables Forecast Energy Consumed by Smart-Metered Loads Micro CHP Unbalanced Loads Load flow system study would identify problem areas; given constraints (i.e. load size & location) Microgrid Controller will manage assets to mitigate effects of unbalanced conditions Diesel GenSet Page 6 Safety Additional Features Coordinate Protection Relay Setting Groups Coordinate Anti-Islanding Safety Feature (if required) Coordinate Black-Start Optimize energy production and load based on emissions, or cost, or both
Advanced Microgrid Control Architecture Page 7
Advanced Microgrid Control Hierarchy Tertiary Control Load Forecast Genera6on/Load Op6miza6on (Economic,or Emission, or Both) Genera6on Forecast Greater than 15 sec Advanced Optimization Forecasting Data Concentra6on Secondary Control Genera6on/Load Reserve Monitoring Management SCADA Voltage Regula6on 4 15 sec Generation Control Load Control SCADA PV Inverter Control Reciproca6ng Gen Control ESS Inverter Control Recloser Control Distributed Energy Resources (DER) Solar PV Primary Control Reciproca6ng Gen Energy Storage Down- Feeder Volt Regulators and Cap Bank Control 0-4 sec Protection Switching Logic Key: Advanced Func6ons SCADA Local Control DER Page 8 Restricted Siemens AG 2014. All rights reserved
Summary of Advanced Control Functions ü ü ü ü ü Maintain frequency Volt/VAR stability by monitoring and controlling Load real power (Watt) Control Forecast balance and ensuring proper reserve margin in local generators Monitor volatility of intermittent generation and loads to disconnect as needed Load (full or Freq. partial) Reg. Shedding Complex Energy Maintain voltage stability by monitoring and controlling reactive power (VAR) Management Local generator dispatch based on programmable criteria (optimized for cost, or emissions, Blackstart or both) Load forecast Renewable Shedding Gen. Optimization ü Generation forecast (based on weather, local fuel reserve, etc ) Gen Reserve Gen. Margin Forecast Page 9
Thank You! QUESTIONS? Page 10
BACK UP SLIDES Page 11
Many Facets of Microgrid Control Fault Location Analysis Manage DG DG Assisted VVC DER Forecast Distr. Network Modeling Data Analysis Bulk Renewable Integration Distributed Analysis DER Trading Platform Coordinate DSM Page 12 Source: GTM Research
Siemens @ European Utility Week 2014 Page 13
Topology of Microgrid Controls Primary Controls Protection Switching Logics Automation Controller Secondary Controls Gateway/Protocol Controller Data Concentrator ISO Interface Advanced Optimization Tertiary Controls Forecasting Regulation SCADA Page 14
Island Grids & Microgrids Energy Manager Secondary Frequency Control Generator management Microgrid Control Platform Storage management Load forecast Local Production forecast Weather forecast Load management SCADA - Grid Monitoring & Control Page 15