1. Electromagnetic Interoperability Issues Working Group
Guide for Products Tested for EMC Performance
February 12, 2019

2. Background Approximately 1,100 Members Founded in 1992
SEPA’s Mission is to to facilitate the electric power sector industry’s smart transition to a clean and modern energy future through education, research, standards, and collaboration.
Approximately 1,100 Members
Founded in 1992
501(c)3 membership organization

3. Who We Are Membership Board 700 Utilities ( IOU, Coop, Muni, PMA)
305 Corporate (Technology Providers, Developers, Consultants)
175 Other (Gov’t Agencies, Commissions, Universities, Labs, NGOs)
Board
116 Coop, 107 IOU, 355 Muni

4. Guide for products tested for EMC performanceBy
Don Heirman
Chair of the SEPA Electromagnetic Interoperability Issues Working Group
Introduction

5. Electromagnetic Environment - 1
The figure below indicates a simplified view of the communications overlay for the power grid, which makes the grid “smart”
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

6. Preface
Document provides guidance for testing labs and Smart Grid device manufacturers to determine the devices immunity to various electromagnetic environments
It includes
Descriptions on different levels of immunity testing for different electromagnetic environments
Design considerations and testing guidelines for prototype devices still in development
Examples of test sequences that EMC Test labs can consider

7. Background Reference is made to previous whitepapers:
Evaluation of the Electromagnetic Phenomena Issues on Smart Grid Reliability addresses the extent and severity of Smart Grid device operation in the electromagnetic environment. It also addressed the need for testing these devices to ascertain their immunity to the environment.
EMC Test Setups for Smart Grid Devices shows that these types of tests are more complex than those commonly performed by EMC laboratories, mainly in the way they determine any degradation condition to both the power measurement and the accompanying communication channel that is beyond that is allowed or tolerated by the manufacturer of the device.

8. Introduction Guide is for:
EMC independent test labs that determine if devices are immune to the electromagnetic environment; test levels are estimated in various reports noted in the EMIIW WG previous white paper: Evaluation of the Electromagnetic Phenomena Issues on Smart Grid Reliability and EMC Test Setups for Smart Grid Devices.
Device manufacturers’ internal test labs that use immunity test results to evaluate EMC immunity problems in device prototypes under development, particularly if they are sold in areas of the world where EMC immunity testing is required.

9. Options in EMC test sequences
1. Apply an immunity test method that has a high probability of potentially not passing the test. Then a design change or a mitigation is applied, and a retest occurs. If the devices pass that test, the rest of the immunity tests are performed, and there is a higher probability that the device passes all tests.
2. Apply an immunity test method that is considered a benign test when a pass is expected. Then the rest of the test methods are conducted with the last test being the one that has the highest probability in stressing the device to the point of failure.
3. Use any sequence of test methods and when the device fails a particular test to stop and mitigate the device to pass that test and then continue on with the rest of the test scenarios.
4. Do not test at all and see if the device operates as intended in the electromagnetic environment where it is installed; if there are installed devices that succumb to the environment find a “fix” that can be installed where there are failures.

10. Selection of Immunity tests and test levels
IEC X EMC Immunity Tests for Smart Grid Device Testing
4-2 Electrostatic Discharge (ESD)
4-3 Radiated RF immunity
4-4 Fast Transients/Bursts
4-5 Surge (lightning)
4-6 Conducted RF immunity
4-8 Power-frequency magnetic fields
4-10 Oscillatory magnetic fields
4-11 Voltage Dips/Interruptions - ac
4-12 Oscillatory Surge Withstand
4-16 Common mode disturbances
4-17 Ripple on dc input power port
4-18 Damped Oscillatory Wave
4-29 Voltage dips/interrupts - dc
As indicated in two previous white papers produced by the EMIIWG, shown here is a suite of immunity tests that are considered to be a minimum number to assess the immunity of a device to a wide range of typical EM sources that can significantly affect device operation. Table 2 from EMC Test Setups for Smart Grid Devices identifies typical immunity tests that should be performed to determine if these devices reliably perform within specifications. Guidance documents:
IEEE-1613(2009) + IEEE (2013) and their successor IEEE-P1613 (201x)
IEC (2013) Communication networks and systems for power utility automation
IEC (2015) Immunity for equipment used in power station and substation environment
Guidance Documents
Guidance Documents
IEEE-1613(2009) + IEEE (2013)
IEC (2013)
IEEE-1613(2009) + IEEE (2013)
IEC (2013)
IEC (2015)
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

11. Some issues to consider when selecting the test sequence
Start with the test that is most likely cause damage
Find any issue that have to be mitigated before continuing the rest of the lesser impact tests.
Start with the test that is least likely to cause damage and then continuing through the test sequence until the test most likely to cause damage
Maximize the information obtained before the device is subject to damage.
The test sequence may be limited by the availability of test equipment or lab facility space.
In this situation, the lab schedule, may dictate the test sequence.
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

12. More on Sequence/Order of EMC Testing
The results of the EMC immunity tests are independent of each other.
The tests may be performed in any order.
The EUT must be functional, undamaged in any way, and meet its performance requirements at the start of each test.
Some of these tests may cause damage to the EUT due to the nature of the test and the EUT. The acceptance criteria will define what, if any loss of functions, is allowable.
Most EMC test labs will usually begin with the emission measurements since these tests will not damage the EUT.
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

13. In Case of Failures
If failures (i.e., upsets) are experienced during testing:
A manufacturer may choose to halt testing until the EUT can be redesigned.
May result in longer development times since the EUT may fail the next test and may also need additional design changes.
However, it may be best to complete as much testing as possible to expose the EUT to as many tests as possible.
Could expose multiple design failures at one time but results in more initial testing and retesting. In the end, the EUT must meet all requirements and their associated performance criteria.
A manufacturer might want to start with the test that is most likely to cause a failure.
Expose an EUT’s weakness at the start.
Issues can be handled before moving on and thereby reducing retesting if a redesign is needed.
Often used when multiple samples are available, and a new working sample would be available for the next test if it the previous sample was damaged.
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

14. Ranking of Testing
The tests were ranked by their likeliness to cause damage.
The tests were placed in two group based on the expectation for damaging the EUT.
Assumes that the device damage is primary, and the channel interference is secondary but still important.
The two approaches are identified as Group A and Group B. While results may vary depending upon the EUT.
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

15. Group A (higher expectation of device damage)
For IEC X Immunity Test Standards
4-2 Electrostatic Discharge (ESD)
4-5 Surge (lightning)
4-12 Oscillatory Surge Withstand
4-16 Mains frequency voltage common mode
4-11 and 4-29 Voltage Dips/Interruptions
4-18 Damped Oscillatory Wave
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

16. Group B (lower expectation of device damage)
For IEC X Immunity Test Standards
4-10 Damped Oscillatory magnetic field
4-4 Fast Transients/Bursts (EFT)
4-3 Radiated RF
4-6 Conducted RF on power and signal lines
4-8 Power Frequency magnetic field
4-17 Ripple on DC supplies
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

17. Dependence on ISO/IEC 17025 Test setups documented in a test plan in:
EMC Test Setups for Smart Grid Devices
ISO/IEC 17025, “General requirements for the competence of testing and calibration laboratories” is used for
Internationally accepted and followed by test labs
Organizes the report and the detail needed
Identifies the photos/diagrams of what was tested.
Ensure that nothing important is left out
Facilitate repeating the measurement

18. Organization References are in sequence when they appear in the paper
Primary references are standards mainly from the International Electrotechnical Commission (IEC) as they are resource for most immunity testing standards and also those describing the electromagnetic environment
Special application standards come from IEEE Power and Energy Society work
Standards applicable to high power transients are shown as “references from Annex B”.

19. Examples
3. IEC (2017): Electromagnetic compatibility (EMC) – Part 2-5: Environment –Description and classification of electromagnetic environments
4. IEC (2016): Electromagnetic compatibility (EMC) – Part 6-1: Generic standards - Immunity standard for residential, commercial and light-industrial environments
5. IEC (2016): Electromagnetic compatibility (EMC) – Part 6-2: Generic standards -Immunity standard for industrial environments
6. IEC (2015): Electromagnetic compatibility (EMC) – Part 6-5: Generic standards -immunity for equipment used in power station and substation environment
7. Evaluation of the Electromagnetic Phenomena Issues on Smart Grid

20. Annex B – Severe High- Power Transient Phenomena - 1
While high-power transient events are low probability events, it is well known that when they occur, they are more likely to affect the operation of communications equipment, which operates at lower peak voltage levels than most power equipment (e.g. transformers)
Two principle concerns include the possibility of a HEMP attack over the U.S. or a local IEMI attack using electromagnetic (EM) weapons
A HEMP attack can illuminate a large portion of a power grid (over thousands of km) including its communications systems simultaneously
An IEMI attack is a more local threat, although it is possible that such an attack could affect multiple substations or power stations within a short time frame
The electromagnetic transients produced by these threats include both high peak levels of fields (~50 kV/m) with very high frequency content (MHz into the GHz range). Also HEMP can produce sub-hertz waveforms with peak fields on the order of tens of V/km, which is much higher than the worst case geomagnetic storm threat.
In addition to the radiated transients, high levels of conducted transients are also produced by both threats at high frequencies (above 1 MHz) and at low frequencies (severe power harmonics due to transformer saturation) by HEMP
The expected levels of these transients are described in IEC , 2-10 and 2-13
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

21. Annex B – Severe High- Power Transient Phenomena - 2
With regard to protection from these EM transients, IEC SC 77C has worked for many years to provide protection methods that can be applied to a variety of commercial equipment and systems
These protection methods are based on standard EMC protection techniques including the use of shielded buildings, rooms, or racks to reduce the external fields to levels that can be tolerated by normally produced electronic equipment (which are designed to EMC standards)
Conducted transients are reduced by the use of surge arresters and filters, but designed for the particular transients of interest
The entire collection of IEC SC 77C high power EM standards are coordinated in a recent publication, IEC , “Guidance on the protection of facilities against HEMP and IEMI”
It is noted that these high-power EM transient standards rely strongly on testing to ensure compliance, whether the testing is performed at the equipment or system level
As in the case of EMC testing, it is important to test the critical functions of the equipment under test including any communications functions
This meeting, and all SEPA activities, are governed by SEPA’s By-laws and policies.
(Including the Intellectual Property Rights Policy and Antitrust Policy.)
SEPA © 2018 |

22. Key takeaways
Smart Grid device immunity to the electromagnetic phenomena is critical for reliability and performance
Assessing the EMC of devices is needed by performing immunity tests identified in document
EMC review is needed at both the device manufacturer in-house testing and at the EMC test laboratories immunity assessment of the device perspectives
The sequence of immunity tests varies and is left with the test lab to apply based on experience
Attention should be paid to even a severe electromagnetic environment where fast rise time high power pulses may be present.

23. Thank you for your attention!