NW Energy XP Project Grid Impacts of Embedded Energy Storage for Distributed PV Systems with Advanced Inverter Controls Student Team: John Hofman (WSU), Taylor Redding (OIT), Umid Mamadaminov (OIT), Andrew Hill (OIT) Advisors: Professor Xiaodong Liang P.E. (WSU), Professor Frank Rytkonen P.E. (OIT)
Presentation Outline Project Introduction Problem and Objective Changes to IEEE 1547 How Problem has been Addressed Our Solution and its Advantages General Design Concept Next Steps
Problem Problems with High Penetration of Rooftop PV Variability of Solar Insolation Generation Ramp Rates Volt/Var Control Voltage/Frequency Ride-Through Cascading Fault Issues with DG HTTP://WWW.NREL.GOV/ELECTRICITY/TRANSMISSION/SIND_TOOLKIT.HTML
Objective Determine a solution that: Significantly addresses grid stability and power quality issues with high penetration of PV on distributed networks Does not add significant cost to current practices May be scalable
General requirements: 4.1.1 Voltage Regulation Recent Changes to IEEE 1547-2003 IEEE-SA Standards Board approved the Amendment to Std 1547TM-2003 on May 2014. Response to Area EPS abnormal conditions: 4.2.3 Voltage 4.2.4 Frequency
Interconnection system response to abnormal voltages IEEE 1547-2003 IEEE 1547a - 2014 Voltage range (% of base voltage a ) Clearing times (s) b V<50 0.16 50 V 88 2.00 110<V<120 1.00 V 120 0.16 a Base voltages are the nominal system voltages stated in ANSI C84.1-1995 Default settings a Voltage range (% of base voltage b ) Clearing times (s) Clearing time adjustable up to and including (s) V<45 0.16 0.16 45 V 60 1 11 60 V 88 2 21 110<V<120 1 13 V 120 0.16 0.16 a Base voltages are the nominal system voltages stated in ANSI C84.1-2011
Interconnection system response to abnormal frequencies IEEE 1547-2003 IEEE 1547a - 2014 DR size Frequency range (Hz) Clearing time (s) 30kW >60.5 0.16 <59.3 11 >30kW >60.5 21 <{59.8-57.0} Adjustable 0.16 to 300 <57.0 0.16 Function Default settings a Frequency (Hz) Clearing time (s) Range of adjustability Frequency (Hz) Clearing time (s) adjustable up to and including UF1 <57 0.16 56-60 10 UF2 <59.5 2 56-60 300 OF1 >60.5 2 60-64 300 OF2 >62 0.16 60-64 10
How the Problem has been Addressed California Energy Storage Mandate Various Companies to Install 1325 MW Storage/Grid Stability Completion 2024 2 MW Battery System Large Scale HTTP://SPECTRUM.IEEE.ORG/ENERGYWISE/ENERGY/RENEWABLES/CALIFORNIAS-FIRSTINNATION-ENERGY-STORAGE-MANDATE
How the Problem has been Addressed Germany Econamic Grid by Intelligent Energy Solutions (IES) Home Based System 800kWh Free Energy Off Hour Use Medium Scale Econamic Grid Hardware http://www.senec-ies.com/produkt/senec.home_g2/ HTTP://WWW.RENEWABLEENERGYWORLD.COM/REA/BLOG/POST/2014/06/ENERGY-STORAGE-A-DIFFERENT-VIEW-FROM-GERMANY
How our project differs, and the advantages it offers Distribution Feeder Category A Short Lines Underground Strong Source Distribution Feeder Category B Medium Lines Overhead Medium Source Distribution Feeder Category C Long Lines Overhead Weak Source 10% Solar No Issues No Issues No Issues 20% Solar No Issues No Issues Minor Issues (e.g. light flicker, Occasional Voltage violations, slight increase of control operations, etc.) 30% Solar No Issues Minor Issues (e.g. light flicker, Occasional Voltage violations, slight increase of control operations, etc.) Major Issues (e.g. severe flicker, frequent voltage violations and control operations, reverse current flow, inverter tripping, etc.) 100% Solar Major Issues (e.g. severe flicker, frequent voltage violations and control operations, reverse current flow, inverter tripping, etc.) Major Issues (e.g. severe flicker, frequent voltage violations and control operations, reverse current flow, inverter tripping, etc.) Major Issues (e.g. severe flicker, frequent voltage violations and control operations, reverse current flow, inverter tripping, etc.) Table 1: PV penetration vs. types of distribution feeders [Source: UVIG ] HTTP://WWW.TECHADVANTAGE.ORG/WP-CONTENT/UPLOADS/2014/03/6D_SCHOENE.PDF
How our project differs (continued) 0.80 Centralia College PV Data 0.70 0.60 0.50 kwh 0.40 0.30 0.20 0.10 0.00 9/2/13 0:00 9/2/13 4:48 9/2/13 9:36 9/2/13 14:24 9/2/13 19:12 9/3/13 0:00 9/3/13 4:48 9/3/13 9:36 9/3/13 14:24 9/3/13 19:12 9/4/13 0:00 Date Range
General Design Concept and Benefits Key elements of the project: Include minimal storage element to currently available advanced inverter technologies Battery serves to regulate inverter input Inverter may then perform advanced control features more predictably and effectively with less transient effects to due sudden changes in available insolation May increase lifetime of power electronics due to less extreme switching Amass a significant aggregation of energy storage to aid grid stability and power quality May benefit both customer and utility with minimal costs to either
General Design Concept ~94-98% ~92-99% PV Panel MPPT Charge Controller Inverter w/ Advanced Grid-Support Features Utility Increased production of ~10-30% with microinverters for multi-panel arrays Storage ~80-90% Benefits: Gen. ramp rates Volt/Var Control Volt/Freq Ride-Through
Next Steps 1. Design, Build, and Characterize OIT Campus Programmable DC Power Supply Grid Simulator Programmable AC Load Bank OIT Campus Centralia College 6 175 W PV panels with Enphase micro-inverters Good for data collection Centralia College KNOLL Renewable Energy Display