Interconnection of Utility-Scale Solar PV to Distribution
About this course
Understanding utility distribution systems and utility requirements for Solar PV connections to the utility grid takes a special but essential knowledge base. The developer or engineer needs a working knowledge of:
- IEEE Standard 1547-2018
- Medium-Voltage Lines and Substation Equipment
- AC Overcurrent Protection
- Fuses, Reclosers, and Circuit Breakers
- Step-Up Transformer Winding Connections and Ratings
- Volt/VAr Control and Power Factor
- Differences Between Transmission and Distribution
- Unintentional Islanding
- Inverter Control Modes
- Hosting Capacity for Feeders and Substations
- Ground-Fault Over-voltage (GFOV)
- Effective Grounding and Grounding Transformers
Why Take This Course
This course provides solar PV and electric utility professionals an understanding of utility distribution systems, and the considerations in connecting utility-scale solar PV to distribution systems.
What You Get
This course has been designed so that you will:
- Get a thorough understanding of the considerations and criteria for successful interconnections of utility-scale solar PV to utility distribution
- Become conversant in the language and concepts of utility distribution systems, and have better conversations during solar PV project development and execution
- Become more valuable to your organization, and enhance your career progression in the connection of utility-scale solar PV to utility distribution
What You Can Expect
The course is technically-oriented and focused on electric power concepts, equipment, and applications. However, the material is presented from the “ground-up”, so that if you are a non-engineer or are new to utility-scale solar PV plants and utility distribution systems, you can progress easily through the content with little trouble.
Visual Learning
Extensive use of graphics is used in the instructional videos, and you can download a copy of all class material for future use.
In this course, Tim Taylor, Owner of Electric Distribution Academy, brings his 30+ years of experience in utility distribution systems, utility-scale solar plants, and interconnection requirements to give students the background to succeed in the growing utility-scale solar PV industry.
Tim provides an extensive list of resources that you can use in the future for more in-depth conversations on key topics.
Tim is readily available through the class discussion board.
In preparation for this course students should take Tim's free course "Overview of Electric Distribution Systems"
Ready To Sign Up Today? Click Here to Enroll
Course outline
8 modules • 130 assignments • 16:08 hours of video lectures
Welcome • 4 assignments
Orientation Materials
This course is self-paced, so you don’t need to be logged in at any specific time. You can get started immediately after you enroll and the course materials will remain in your account with minimum guaranteed access for 12 months (1 year) after enrollment.
- Set up email notifications and your student profile
- Introduce yourself on the discussion board
- Class Launch Video (01:47 minutes)
- Course Introduction from Tim (11:44 minutes)
Module 1 • 13 assignments
Generation and Transmission Systems
The overview of Generation and Transmission systems provides context around utility-scale solar interconnections to T&D systems. This week we take a look at the different types of generation on utility systems, including central station (steam) thermal types of generation; an overview of the different types of renewables generation; and a discussion on utility transmission systems, including concepts, architectures, and operating principles.
- Lecture 1 - Electric Power Systems and Generation (19:41 minutes)
- Lecture 2 - Large Central Generating Stations (11:35 minutes)
- Lecture 3 - Other Types of Large Generating Stations (16:23 minutes)
- Read: Generation
- Watch: Hydroelectric Innovation
- Lecture 4 - Overview of DER Technologies (30:28 minutes) Preview
- Solar Power and the Electric Grid (.pdf)
- Lecture 5 - Transmission in the US and Transmission Lines (26:47 minutes)
- Read: Transmission
- Lecture 6 - Bulk Power Systems and DER (23:21 minutes)
- Read: FERC Order No. 2222
- Week 1 Presentation Materials (.pdf)
- Generation and Transmission Systems
Module 2 • 12 assignments
Voltage, Current, and Power Fundamentals
There are some basic electric fundamentals that anyone working with solar and utility systems needs to know. This week covers topics such as voltage, current, and power; impedance; watts, vars, and volt-amps; power factor; single-phase and three-phase circuits; and grounding.
- Lecture 1 - Basic Definitions and DC Electricity (14:18 minutes) Preview
- Read: Circuit Basics
- Read: Basic Electrical and Electronic Concepts
- Lecture 2 - Alternating Current (AC) (30:10 minutes)
- Lecture 3 - Power and Power Factor (27:45 minutes)
- Lecture 4 - Three Phase Power (28:50 minutes)
- Watch: Generation of Three-Phase Power
- Homework Problems (.pdf)
- Homework Solutions (.pdf)
- Quiz - Voltage Current and Power Fundamentals
- Week 2 Presentation Materials (.pdf)
- Supplemental Material on Per Unit System (.pdf)
Module 3 • 16 assignments
Distribution Systems
In the next week-and-a-half, we look at the common characteristics of North American style utility distribution systems. This knowledge is intended to give you background on the historic context of distribution systems, and why it can sometimes be challenging to connect large amounts of solar PV to it. This includes basic design and operating concepts, architectures, voltage levels, equipment, and operating principles. We'll look at the impact that distribution characteristics have on the location and quantity of solar on the system, including source impedance; radial, looped, and networked systems; minimum and peak feeder loads; feeder sectionalizing; and system stiffness.
- Lecture 1 - Overview of Utility Distribution (14:47 minutes)
- Lecture 2 - Electric Customer Loads (14:42 minutes)
- Lecture 3 - Subtransmission (13:27 minutes)
- Lecture 4 - High-Voltage Side of Substations (18:17 minutes)
- Watch: 500 kV Circuit Breaker and Disconnect Switch Operation
- Watch: Three Types of Transmission Disconnect Switches
- Lecture 5 - Distribution Substation Transformers (11:21 minutes)
- Lecture 6 - Distribution Substation Low-Side Equipment (10:49 minutes)
- Lecture 7 - Substation Protection, Control and Monitoring Equipment (19:46 minutes)
- Watch: Medium-voltage Switchgear
- Lecture 8 - Introduction to Distribution Feeders (25:20 minutes)
- Distribution Feeder Diagram (.pdf)
- Common Distribution Measurement Units and Quantities (.pdf)
- Read: T&D System (.pdf)
- Typical Electrical Drawing Symbols and Conventions
- Week 3 Presentation Materials (.pdf)
Module 4 • 17 assignments
Distribution Systems and Utility-Scale Solar PV Interconnection
In this week, we'll finish the material on distribution systems and then progress into the first part of Utility-Scale Solar PV Interconnection.
- Intro Lecture - Week 4 (02:02 minutes)
- Lecture 1 - Overhead Conductors (22:24 minutes)
- YouTube: Overhead Line Conductors
- Lecture 2 - Underground Cables and Three-Phase Transformers (19:14 minutes)
- Medium-Voltage Transformers
- Lecture 3 - Feeder Architecture (15:18 minutes)
- Lecture 4 - Distribution System Grounding (10:31 minutes)
- Solar PV Overview
- Watch: Solar PV Electric Power Generation
- Trends in Solar PV - End of 2021
- Lecture 5 - Utility-Scale Solar PV Plants and PV Plant Equipment (25:58 minutes)
- Lecture 6 - Solar PV Plant Equipment (19:12 minutes)
- Read: DC Combiner Boxes
- Transformers for Solar Farms I (.pdf)
- Transformers for Solar Farms II (.pdf)
- Week 4 Presentation Materials (.pdf)
- Overhead Conductors, Underground Cables, and Transformers
Module 5 • 17 assignments
Utility-Scale Solar PV Interconnection on Distribution
In this module, we start with the basics of solar PV farms on distribution, before we get into more detail in the coming weeks. We start by looking at common solar PV issues on distribution. We also look at topics such as interconnection requirements including equipment and its function, inverters and their functionality with respect to the grid, grounding, SCADA connection and communications, and transformer winding configurations.
- Intro Lecture - Week 5 (01:47 minutes)
- Lecture 1 - Solar PV Plant Layouts (18:57 minutes)
- Read: PV Power Plant AC Collection Systems (.pdf)
- Lecture 2 - Useful Metrics (09:04 minutes) Preview
- Read: Inverter Loading Ratio
- Lecture 3 - High-Penetration Solar PV and Smart Inverter Development (21:07 minutes)
- Read: Smart Inverter Benefits
- Lecture 4 - Overview of IEEE 1547-2018 (16:58 minutes)
- Read: Impacts of DER on T&D System (.pdf)
- Lecture 5 - IEEE 1547 and Frequency Requirements (12:25 minutes) Preview
- Lecture 6 - IEEE 1547 and Power Quality (05:09 minutes)
- Lecture 7 - IEEE 1547 and Interoperability (13:29 minutes)
- DNP3 Protocol
- Lecture 8 - IEEE 1547 and Certification/Testing (12:46 minutes)
- Read: Advanced Inverter Tests (.pdf)
- Example of Inverter Listing Request Instruction (.pdf)
- Week 5 Presentation Materials (.pdf)
Module 6 • 15 assignments
Distribution Voltage Regulation and Solar PV Generation
Distribution voltage control/regulation, as well as reactive power control, is one of the most important design and operating principles that a utility must consider. With the introduction of IEEE 1547-2018, solar plants are facing new voltage control requirements. During this week, we'll look at voltage requirements that utilities must provide their customers; voltage drop that occurs on distribution feeder primaries and secondaries; utility voltage control equipment; common impacts of solar installations on utility voltage supply; and possible solutions to voltage issues created by solar installations, including smart inverter controls impacting voltage and reactive power. We also discuss voltage flicker and sags, and inverter ride-through capability.
- Intro Lecture - Week 6 (14:37 minutes)
- Lecture 1 - Voltage Ranges and Voltage Drop (26:41 minutes)
- Lecture 2 - Voltage Regulators (18:15 minutes)
- Watch: Voltage Regulator Controller
- Read: Feeder Voltage Regulation (.pdf)
- Lecture 3 - Capacitors, Reactive Power, and Voltage (16:16 minutes)
- Lecture 4 - Solar PV and Feeder Voltage Profiles (15:06 minutes) Preview
- Lecture 5 - Solar PV and Voltage Variability (02:57 minutes)
- Lecture 6 - IEEE 1547 and Voltage Regulation (14:37 minutes)
- Lecture 7 - Reactive Power Control Modes (18:49 minutes)
- Read: Voltage Control and DER
- Read: IEEE 1547-2018 and Solar PV Reactive Power/Voltage Control (.pdf)
- Lecture 8 - Abnormal Operating Performance and Voltage Ride-Through (09:03 minutes)
- Voltage Control and Monitoring
- Week 6 Presentation Materials (.pdf)
Module 7 • 18 assignments
Distribution Protection and Solar PV Generation
Short-circuits and overcurrent protection is a key design consideration for utility systems, with considerations on solar plant design and operation. This week we'll look at the nature of distribution system faults, overcurrents, and key design principles including instantaneous and time-delayed tripping, reclosing, and post-fault restoration practices. We'll discuss over/under voltage and frequency events on the system, and how they impact the solar PV plant. We'll also look at the potential for unintentional islanding and ground fault overvoltages, and possible mitigation measures, including 3Vo protection and DTT (Direct Transfer Trip).
- Intro Lecture - Week 7 (03:24 minutes)
- Lecture 1 - Distribution System Faults (21:37 minutes)
- Watch: The Reason Why System Protection is Needed
- Lecture 2 - Distribution Protection Objectives (20:31 minutes)
- Lecture 3 - Relayed Circuit Breakers and Fuses (13:15 minutes)
- Watch: Operation of Explusion Fuse
- Lecture 4 - Reclosers (12:29 minutes)
- Watch: Demonstration of Recloser Features
- Watch (Optional): Reclosers Overview
- Read: Solar PV Tie Recloser
- Read: Distribution Protection Overview
- Lecture 5 - Solar PV and Distribution Protection (09:47 minutes)
- Lecture 6 - IEEE 1547-2018 and Overvoltages (14:07 minutes)
- Lecture 7 - IEEE 1547 and Islanding (13:38 minutes) Preview
- Lecture 8 - Selected Protection Requirements from Utilities (06:25 minutes)
- Read: Summary of Smart Inverters and IEEE 1547-2018 (.pdf)
- Week 7 Presentation Materials (.pdf)
- Quiz - Protection and Solar PV
Module 8 • 13 assignments
Hosting Capacity and Interconnection Procedures
Estimating what the impacts of new solar PV farms on distribution systems is important for utility engineers as well as developers. In this section, we look at some Hosting Capacity studies and maps which some public service commission and distribution organizations now use, some additional technical screens, and an overview of distribution interconnection procedures.
- Lecture 1 - Introduction to Hosting Capacity Analysis (15:05 minutes)
- Watch: Demonstration of a Utility's Hosting Capacity Map (26:28 minutes)
- Lecture 2 - Hosting Capacity Criteria and Thresholds (19:52 minutes)
- Read: IREC Hosting Capacity Analysis White Paper
- Lecture 3 - Solar PV Screening Ratios (12:32 minutes)
- FERC SGIP - For Generating Facilities No Larger Than 20 MW (.pdf)
- Lecture 4 - Interconnection Procedures (28:31 minutes)
- Summary of the Fast Track and Supplementary Review Process (.pdf)
- Lecture 5 - The Study Process, Including System Impact Studies (15:52 minutes)
- Read: Tips for Successful Interconnection of Small Renewables (.pdf)
- IREC Model Interconnection Agreement (.pdf)
- Week 8 Presentation Materials (.pdf)
- Utility-Scale PV Resources (.pdf)
Conclusion • 5 assignments
Feedback and Additional Resources
This is our last module but you still have access to the all of course materials for 12 months (1 year), so keep working and you'll be able to complete the course at your own pace. After your year of access expires you can optionally extend access with a HeatSpring Membership. Enjoy the course and keep in touch!
- Optional: Get IEEE Continuing Education Credit for Completing this Course (.docx)
- 1 Year of Access to Course Materials
- Feedback: 2-minute Exit Survey
- Consider Joining as a HeatSpring Member
- Certificate of Completion: Request a Certificate
Continuing Education Units
Approved for the following CEUs
- NABCEP Advanced Credit Hours
- NABCEP NEC
- NABCEP JTA
- NABCEP PV Associate Renewal
- 2.4 IEEE CEUs
Approved NABCEP CEU Hours
NABCEP Credential | Advanced Hours for Exam | Recertification CEU Hours | NEC | JTA | RE Elective | Building or Fire Code |
---|---|---|---|---|---|---|
17 | 24 | 0 | 17 | 12 | 0 | |
0 | 12 | 0 | 0 | 0 | 0 | |
17 | 24 | 0 | 17 | 12 | 0 | |
17 | 24 | 0 | 17 | 12 | 0 | |
17 | 24 | 0 | 17 | 12 | 0 | |
17 | 24 | 0 | 17 | 12 | 0 |
NABCEP Registered Provider
This course counts towards the training requirements for taking NABCEP professional certification exams and CEUs for renewing all certifications.
Instructor
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Tim Taylor
Owner and Managing Director, Electric Distribution AcademyTim is Owner and Managing Director of Electric Distribution Academy and has over 30 years of experience in distribution system engineering. He’s led and participated in many projects with many North American utilities and has also worked in Europe and Latin American. In addition to papers, articles, and conference presentations, he has served as an instructor for... Learn more