CERTS Microgrids. Tom Jahns Professor, University of Wisconsin-Madison. LPPC Rates Roundtable May 21, 2013

Transcription

1 CERTS Microgrids Tom Jahns Professor, University of Wisconsin-Madison LPPC Rates Roundtable May 21, 2013

2 Wisconsin Energy Institute WEI WEI provides linkage among all organizations associated with energy science, technology and policy work at UW-Madison

3 DER Technologies Dispatchable Sources Small internal combustion-engine generator Small gas turbines generators Microturbines Fuel cells Intermittent Sources Wind turbines Photovoltaic Storage Batteries, Ultra-capacitors Flywheels How do we deal with 100,000+ DER units?

4 Cluster Loads & DER (interfaced to the grid using a fast switch) Microgrids provide the most promising means of integrating large amounts of distributed sources into the power grid Microgrids open the door to significant system efficiency reliability improvements :.65% 4;"51<%!"#$% &'()"#*% +,% -((./% 0"1(2% &'()"#*% 3*#4*56% B2.$6% 7.8*(/%452(.9*% :'*=%>*==6% +='9?@#%A/)("$% :=/;<**=%!"

5 Microgrid Drivers Provides system approach to high penetration issues Reduce load outages by ~ 98% (UPS like system) Fast islanding (~1 cycle) Provides for a stiff voltage during events (SVC) Reduced emissions and improve energy efficiencies Effective use of Combined Heat & Power (CHP) No transmission and distribution losses Facilitates demand side management Support renewable sources Provides higher reliability & modularity Autonomous local control (independent of loss of central controller) Graceful degradation Minimize engineering errors/cost/and maximizes flexibility Plug-and-play & peer-to-peer models

6 Microgrids with Fast Controls and Communications Isolating Device (opens during island mode) Utility System Primary Connection (13.2 kv) Utility System Interface Control (Synchronization, fault protection, islanding detection, etc.) Generator Protection and Control Load control Paralleling Bus (4.8 kv) Gen 1.75 MVA 1.2 MVA 0.8 MVA 1.75 MVA Gen Gen 1.75 MVA Heat Distribution Communication & Control Signal Path 1.4 MVA Issues: Loss of control & communication! Extensive site engineering Costly heat distribution system. Difficult to scale Heat Recovered from ICE Units EPRI: Campus Microgrid System 6

7 CERTS Microgrid: Autonomous Components 120 kv Microgrid with local Combined Heat & Power! Microgrid + CHP! 13.2 kv Microgrid + CHP!! CH P PV CH P Controller P V L L L c L c L c Storage PCC Other loads Autonomous DER model (independent of central controller) Plug & Play Model (avoids extensive site engineering, design errors & allows placement near heat/cooling loads) Units control power, frequency & voltage using local information 7

8 CERTS Microgrid V o l t a g e F r e q u e n c y V m a x p u 1 p u V r e f p u V m i n Q l i m i t Q l i m i t I n d u c t i v e R e a c t i v e P o w e r C a p a c i t i v e Reactive power-terminal voltage droop 0. 5 p u 1. 0 p u Real power-frequency droop R e a l P o w e r Control of individual DG s is achieved using local information only Power is balanced using power frequency droop curves Voltage is controlled using reactive power droop curves

9 CERTS Microgrid Concept Each DER unit is a grid-forming component (controls ac voltage and frequency). Autonomous load following Insures multi-unit stability (local voltage control) Autonomous load transfer from overloaded source to other sources Intelligent load and source shedding The interface switch provides for autonomous islanding and re-synchronizing to the network (opens on IEEE1547 & power quality events)

10 UW Microgrid Testbed Utility System Static Switch 480 V 208 V Static Switch" 20 yd 4 wire Cable 9.0 kw Y Loads Diesel Genset DG V 75 yd 4 wire Cable 25 yd 4 wire Cable 480 V 4.5 kw Y Load 9.0 kw Y Loads DG 1 Inverter-Based Microsources 480 V DG 2 Testbed has been used to develop robust plug-and-play control algorithms defining CERTS Microgrid

11 Demonstrated at Site (inverter-based, no communications & no storage)!!autonomous load following!!seamless separation & automatic re-synchronizing with the grid!!autonomous load transfer from overload source to other sources!!ups-level power quality!!stable operation for multi-sourced systems AEP/CERTS Microgrid Test Bed 3-60 kw Sources Static Switch #$#"%&$'" """"""())*+())," -.$"'-/&" """"""()),+())0" -.$"/1234"536789:" """""""())0+;3<=<>4" Loads

12 First CERTS Compliant First product to commercially offer CERTs controls algorithms for microgrid operation Features:! Low emission NG engine! Operated over wide speed range to optimize fuel efficiency! 700,000 BTUh recoverable heat! 82.4% (LHV) overall efficiency CHP Systems TecoGen

13 "! Alameda County, Santa Rita Jail CERTS Microgrid Demonstration Objective Demonstrate the commercial implementation of the CERTS concept Reduce peak electricity demand & demonstrate demand response Improve the security and reliability of the power supply Improve the fuel cell s performance Equipment 4 MW-hr Lithium Ion battery Two 1 MW diesel generators Smart switch 1 MW fuel cell with CHP 1.2 MW solar on rooftops 12 kv feeder DOE &CEC funded project

14 Military Microgrids! Fort Sill Energy Efficient! Microgrid! Hybrid CERTS Microgrid 500 kw hr battery kw NG gen-sets 30 kw PV 2.5 kw wind Advanced Distribution and! Control for Hybrid Intelligent! Power Systems:! Meshed microgrid with a reliable wireless communication system Intelligent distributed controls to promote graceful degradation! MAXWELL Air Force Base! Interconnecting two buildings Demonstrate CERTS advanced controls 2- existing MW gen-sets

15 Wisconsin Energy Institute Building >2CD=*5*$%"#% )./%C"1(29("$%=.)%

16 New UW-Madison WEI $"&%)".+/%'0%123%45% 6'7*)%&(88-9*&%"+,%,:+'&%#'+;)'--*,%;'% *<(-";*%=!%&'()#*&%% *,"

17 What's next? Coupled Microgrids Smart Switch: Seamless separation Automatic re-synchronizing Two coupled microgrids: Distribution level Customer level with high Local Reliability & CHP Standard building block for Smart Distribution 17

18 What is Next? Microgrid as a Grid Resource PV CHP Controller PV L L L c L c L c CHP Storage Provides a standard building block for Smart Distribution. Dispatchable bi-directional real & reactive power. Demand side management. Multiple points of electrical coupling. Islands & re-synchronizes autonomously.! Controller interfaces with system controllers. and locally optimizes the microgrid operation. Can have custom features 18

19 For Discussion Can utilities and microgrids be friends? Is it possible to imagine creating a win-win environment in which utilities embrace DER and microgrids? Are the barriers inherent in the basic regulated utility structure? Can ratemaking improve the relationship between utilities and microgrids?

20 For More Discussion. Please contact: Prof. T.M. Jahns