Integration of DER: Grid Support Functions and Connectivity P174B 2016 PDU Fall Advisory Meeting Aminul Huque, PhD Principal Technical Leader mhuque@epri.com Brian Seal Sr. Program Manager bseal@epri.com Hollywood, FL September 20, 2016
Program 174 - Integration of Distributed Energy Resources Project Sets & Projects Project Set Project Description PS174A - Modeling & Simulation PS174B - Grid Support Functions & Connectivity PS174D - Utility Economics & Practices 174.001 174.002 174.003 174.005 174.008 174.009 Analytics & Methods for Existing Grid Distribution Applications Analytics & Methods for Future Grid Distribution Applications Inverter Advanced Functions & Grid Communication Inverter Performance & System Safety Assessment Utility Practices, Markets, & Use Cases Economic Analysis of Business Impacts & Opportunities PS174E - Technology Transfer & Industry Coordination 174.010 Technology Transfer, Resources, Tools 2
PS174B: Grid Support Functions & Connectivity Value Foster standards for advanced grid support behaviors and communication to integrate DER into power system operation Evaluate smart inverters demonstrate operation and benefits of advanced functions; identify risk of conflicting behavior when operating in parallel Evaluate newer PV and energy storage integration technologies backup support, start-up current, black start, load peak shaving, solar time shifting, and grid import/export control. Leverage & Coordination Energy Storage (P94), ICT (P161), End-Use EE&DR (P170), and Distribution Systems (P180) Distribution Transformer Cable 4/0 Triplex 50 100 300 6kW PV System with Smart Inverter A 6kW PV System with Smart Inverter B DOE SHINES, NYSERDA smart inverter, California smart inverter modular interface projects 6kW PV System with Smart Inverter C 3
PS174B: Grid Support Functions & Connectivity 2016 Deliverables Inverter Advanced Functions and Grid Communication Common Functions for Smart Inverters, 4 th Edition Methods for complimentary use of smart solar, loads, and storage. DER Group Management Functions, 3 rd Edition Technical Update Technical Update Technical Update Inverter Performance and System Safety Assessment Evaluation of Multiple Smart Inverters Operating in Parallel PV and ES Inverter with Integrated Battery Technology Assessment DER Inverter Fact Book, Version 2 Microgrid Controller Test Plan Technical Update Technical Update (PPT) Technical Update (PPT) Technical Update 4
Common Functions for Smart Inverters, Version 4 Continue to Provide Industry Leadership to Align and Define the Grid-Supportive Functions for Solar and Storage Systems Scope Update document to reflect new thinking since its last update in 2013. Facilitate recurring stakeholder working sessions. Engage domain experts and incorporate new contributions. Leveraging CEC Funded Research and EPRI s Energy Storage Integration Council Value This work is the foundation for all smart inverter functionality across vendors, protocols, and DER grid-codes worldwide. Maintaining an updated version of this document promotes uniformity in smart inverter functions enables utilities to cohesively integrate diverse systems. Delivery Type/Date Technical Update, Q4 5
Common Functions for Smart Inverters, Version 4 What activities are feeding into this update? MESA and SunSpec EPRI s ESIC IEC TC57 WG17 UL 1741 Projects and Field Demos IEEE 1547 Common Functions Version 4 California Rule 21 6
7 Common Functions for Smart Inverters, Version 4 Areas Being Edited Pending Updates Low/High Voltage Ride Through Low/High Frequency Ride Through Connect/Disconnect Addition Types of Ramp Rates Added Support for Bi-Directional Power Flow Additional Curve: Watt-Var Synthetic Inertia Function State of Charge Monitoring Points General Terminology Active Discussions Referenced ECP Settable Function Priorities More to come!
Common Functions for Smart Inverters, Version 4 Example change: Update to Low/High Voltage Ride Through Terminology Old Approach: Must remain connected, Must trip New Approach : Cease to energize, May trip, Must trip Regions Old Approach : Lines defined a region above and a region below, notionally with a gap region in the middle. New Approach : Each line defines a zone to its right. The zones are stacked by precedence. 1) Must trip 2) May trip 3) Cease to energize Old Approach New Approach 8
Common Functions for Smart Inverters, Version 4 Example addition: New curve function, Watt-Var 9
Common Functions for Smart Inverters, Version 4 Example addition: Monitoring Points for Energy Storage 10
Methods for Complimentary Use of DER Create a tool for users to evaluate and optimize DER control schemes against a repository of residential data sets Scope Create the framework for a tool to help validate and optimize DER dispatch options for PV support Develop the tool (Excel-based) and report on the use and performance of example scenarios Value Each DER type has unique capabilities. Factors including time-of-day, customer behavior, and endgoal, impact how each DER can help integrate PV most effectively. The evaluation tool allows users to run DER control schemes through thousands of unique residential data sets to understand the best control scenario for a given end-goal. Delivery Type/Date Technical Update, Q4 12
Execution of DER Strategy Residential Scenarios Methods for Complimentary Use General Architecture for the Testbed Device-Level Data Sets Load Shapes Device Parameters Parameters for Residential Scenarios Time Shifting Load Amplitude Adjustments Number of Load Shapes Residential Scenario Calculator Combines reference data sets for individual loads and applies the parameters for residential scenarios to create a set of unique, residential load shapes. Residential Load Shapes (1-min data) DER Control Algorithm/Strategy Applies control strategies to residential load shapes and estimates the resulting load shape. Calculate strategy metrics to help users understand the impact of the strategy. Control Strategy Parameters DER Dispatch Priorities Comfort Thresholds Control Strategy Metrics Resulting Load Shapes Optimization Data Performance Metrics Optimization Parameters Min/Max for Step Variables Interval for Step Variables 13
Methods for Complimentary Use Initial Applications and Uses Flexible architecture allows for custom control strategies. Example control strategy will assess the dispatch order of DER and comfort threshold priorities. Example use-cases will include: Smoothing reducing the intermittency of residential solar Minimize peak load, peak generation 14
Evaluation of Multiple Smart Inverters Operating in Parallel Investigate interaction between multiple smart inverters operating in parallel Scope Testing of three residential smart inverters (SMA, ABB, and Fronius) operating in parallel Investigate interactions while providing grid support including reactive power support, L/HVRT, volt-watt, and frequency-watt Evaluate unintentional islanding prevention capability with advanced grid support functions activated Value Better understanding of the smart inverters in the field at higher PV penetration Delivery Type/Date Tech Update - Report, Q3 Grid Simulator 50kVA 480V to 120/240V 50' 4/0 Triplex Ch 1 Smart PV Inv A 100' 4/0 Triplex 300' 4/0 Triplex Smart PV Inv B Smart PV Inv C Ch 2 Ch 3 Solar PV Array Simulator 2015 technical update # 3002005784 15
Normalized Irradiance (% of STC) Smart Inverter Functions being Tested? Fixed Power Factor Volt-var Volt-watt Volt-var + volt-watt Low/High Voltage Ride Thru (L/HVRT) Low/High Frequency Ride Thru (L/HFRT) Frequency-Watt Max Generation Limit Unintentional Islanding detection with ride-thru and voltage regulation Distribution Transformer 6kW PV System with Smart Inverter C Cable 4/0 Triplex 1.2 1 0.8 0.6 0.4 0.2 0 (May 15, 0112)... 09:00 12:00 15:00 18:00 Local Time 50 100 300 6kW PV System with Smart Inverter A 6kW PV System with Smart Inverter B 16
Laboratory Test Setup Fronius Primo 6.0-1 ABB PVI-6000- OUTD-USA 50kVA 480V to 120/240V SMA SB 6000TL-US-22 17
Voltage Ride-Thru 48% Voltage Sag event for 2.25s C B A T S Service Transformer Inv A VRT = Extended Inv B VRT = Extended Inv C VRT = Extended Trnsfrmr Sec. 18
Voltage Ride-Thru 48% Voltage Sag event for 2.25s C B A T S Service Transformer Limit Exceeded / Inverter Disconnect Inv A VRT = Default Inv B VRT = Extended Inv C VRT = Extended Trnsfrmr Sec. 19
Volt-Var with Variable PV Irradiance Volt-VAR curve C B A T S 95.8% (115V L-N) 104.2% (125V L-N) Service Transformer 20
Volt-Var with Variable PV Irradiance C B A T S Service Transformer Voltage Variability Index (VVI) Unity Volt-Var House A 1.025 1.019 House B 1.027 1.015 House C 1.028 1.019 Transformer 1.022 1.020 21
High Variability Day Impact of Volt-Var on Voltage C B A T S Service Transformer Voltage Variability Index (VVI) Unity Volt-Var House A 1.015 1.011 House B 1.019 1.011 House C 1.023 1.011 Transformer 1.011 1.010 22
Clear Day Impact of Volt-Var on Voltage C B A T S Service Transformer Voltage Variability Index (VVI) Unity Volt-Var House A 1.014 1.017 House B 1.013 1.017 House C 1.013 1.016 Transformer 1.013 1.017 23
Unintentional Islanding Test Setup Switch S L1 480V L-L RLC Load Bank 480V L-L N 120V L-N 240V L-L Programmable Power Supply (~99 L-N) L2 PV Inverter A PV Inverter B PV Inverter C Estimated RLC values prior to fine-tuning: Q f = R C L = 12.8Ω 207μF 34.0mH = 1.0 Rated Current of all three inverters = 75A Fundamental Frequency Current thru switch S limited to 2% of rated current 75A(2%) = 1.5A 24
Unintentional Islanding Smart Inverter Function Settings 95.8% (115V L-N) 104.2% (125V L-N) 104% (124.8V L-N) 25
Unintentional Islanding All Inverters Volt-Watt enabled; Volt-Var enabled C B A T S Opened Switch S Service Transformer 182.25ms 26
Evaluation of PV and ES Inverter with Integrated Battery Laboratory evaluation of PV and Energy Storage integration technologies Scope Commissioning and testing of Sunverge Solar Integration System (SIS) with integrated battery Evaluate load peak shaving, demand dispatch, grid export limit, black start, offgrid load-generation balancing, inrush current capability, etc. Value ES application to mitigate PV variability impact and to improve resiliency Delivery Type/Date Tech Update - PPT, Q4 Sunverge SIS 27
What Functions Will be Tested? Planned Tests: Product review/specifications/software control interface On-grid to off-grid transition Resynchronization to grid Load Peak Shaving/demand savings Black Start Off-Grid Load/Generation Balancing PV export limiting to grid Solar time shifting/ firming Solar smoothing Reactive power support (if available) Short duration overloading capability/ startup current support Interface with generator in off-grid mode Other 28
Load Peak Shaving / Demand Savings Test 1: Variable Load Profile PV generation kept fixed at 3.0kW Starting Battery SOC = 92% Mode of operation for Sunverge was set to Dispatch by Site Demand Charging battery from grid not supported while in this mode. Target site meter reading = 2.0kW ± 300W Discharging Energy Storage Idle Charging (from PV only) Time (min) Load (kw) Irradiance (W/m2) 0 6 610 5 3 610 10 8 610 15 6 610 20 5 610 25 3 610 30 1 610 29
Changing External Load Demand +2kW Non-Critical Load Sunverge SIS + - External load demands DUT only utilized battery to support load due to SOC > 80% 6kW 3kW 8kW 6kW 5kW 3kW 1kW Discharging Energy Storage Charging 30
Response to Step Decrease in Load Demand Demand Meter recorded ~3.0kW import from grid for 1.3s 6kW Load 23.0s 3kW Load 6.8s Demand Meter recorded ~1.0kW export to grid for 6.8s Discharging Charging 31
DER Inverter Fact Book, 2 nd Edition Comprehensive compilation of PV and energy storage inverter technical details including topologies, advanced functionalities, standards, and industry trends Scope Update fact book version 1 (# 3002005785) to include: Energy storage system topologies and technologies Review of sample commercial PV and ES inverter technologies Advanced grid support functions offered by commercial products Status of interconnections standards, including IEEE147, UL 1741Sutdown) Value One-stop resource for PV and ES inverter technical information Delivery Type/Date Tech Update PPT, Q4 32
Residential PV Inverter with Integrated Battery Storage 33
New Inverters SMA STP Core 1 51,000W 1000V DC 98% of CEC Enphase IQ 6/ 6+ Micro 330W/ 400W Panels 230VA (cont.)/ 240VA (peak) 97% of CEC 34
GE s 1500V LV5+ Solar Inverter 2.5MW, SiC MOSFET Source: GE 35
Together Shaping the Future of Electricity 36