IEC TS 63106-1:2020

Simulators used for testing of photovoltaic power conversion equipment - Recommendations - Part 1: AC power simulators

IEC TS 63106-1:2020 provide recommendations for Low Voltage (LV) AC power simulators used for testing utility interactive photovoltaic power conversion equipment (PCE). This document establish terminology, and create a framework for, and provide guidance regarding the electrical performance of AC power simulators used to test utility interactive photovoltaic (PV) power conversion equipment (PCE) for compliance with grid interconnection standards.
It serves as a generalized guideline for the development of AC power simulators used within a test and evaluation system for PV PCEs.

General Information

• Status: Published
• Publication Date: 18-Nov-2020
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: WG 6 - TC 82/WG 6
• Current Stage: PPUB - Publication issued
• Start Date: 19-Nov-2020
• Completion Date: 09-Dec-2020

Standards Content (Sample)

IEC TS 63106-1 ®
Edition 1.0 2020-11
TECHNICAL
SPECIFICATION
Simulators used for testing of photovoltaic power conversion equipment –
Recommendations –
Part 1: AC power simulators
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IEC TS 63106-1 ®
Edition 1.0 2020-11
TECHNICAL
SPECIFICATION
Simulators used for testing of photovoltaic power conversion equipment –

Recommendations –
Part 1: AC power simulators
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-9035-4

– 2 – IEC TS 63106-1:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
4 PCE types with respect to AC voltage levels and grid interconnection . 9
5 Test setup for utility interactive PCEs . 10
5.1 General . 10
5.2 Test setup examples for utility interaction test . 11
5.2.1 General . 11
5.2.2 Types of AC power simulator systems . 11
5.2.3 Load . 12
5.2.4 Line impedance . 13
6 General recommendations for AC power simulators . 13
6.1 General . 13
6.1.1 Overview . 13
6.1.2 AC main connections . 13
6.1.3 Output transformer . 13
6.1.4 Number of phases and voltage range . 13
6.1.5 Frequency ranges supplied to EUT . 14
6.1.6 Voltage stability and accuracy . 14
6.1.7 Frequency stability and accuracy . 14
6.1.8 AC output voltage harmonic distortion . 14
6.1.9 Signal interface for hardware in the loop . 15
6.1.10 Durability against impulse test voltage . 15
6.1.11 Other requirements for test properties . 15
6.2 AC power simulator performance and characteristics . 15
Bibliography . 38

Figure 1 – Examples of ports . 8
Figure 2 – Example of connection of DG systems to utility grid . 10
Figure 3 – Examples of fundamental setup of EUT test system . 11

Table 1 – Typical maximum harmonic voltage distortion (as per IEC 61000-4-7:2002) . 14
Table 2 – Grid qualification/Requalification – In-range voltage before
connection/reconnection . 16
Table 3 – Grid qualification/Requalification – In-range frequency before
connection/reconnection . 17
Table 4 – Power capability: Nameplate P, Q, S under normal and near-normal grid
conditions . 18
Table 5 – Power capability: Limitation of P/Q/S/PF by setpoint . 19
Table 6 – Power capability: Ramp rate or soft start time-developing magnitude by
set rate . 20
Table 7 – Grid protection tests – AC over-voltage (OV) and under-voltage (UV) trip
tests . 21

Table 8 – Grid protection tests: OF/UF trips . 22
Table 9 – Grid protection tests: Anti-islanding . 23
Table 10 – Grid protection tests: ROCOF trips . 24
Table 11 – Grid protection tests: Open phase . 25
Table 12 – Power quality tests: Current harmonics, inter-harmonics, THDi . 26
Table 13 – Power quality tests: Flicker (continuous) . 27
Table 14 – Power quality tests: Current inrush (at connection switch close) . 28
Table 15 – Power quality tests: Current imbalance . 29
Table 16 – Power quality tests: Transient OV on load dump . 30
Table 17 – Grid support tests: UV/OV ride-through with/without Iq injection . 31
Table 18 – Grid support tests: UF/OF ride-through . 32
Table 19 – Grid support tests: ROCOF ride-through . 33
Table 20 – Grid support tests: Phase-jump ride-through. 34
Table 21 – Grid support tests: P (f), PF (P, V), Q (V), P (V) . 35
Table 22 – External command response tests: Magnitude accuracy for P/Q/S/PF by
setpoint . 36
Table 23 – External command response tests: Response to external setpoint changes

(response time, settling time) . 37

– 4 – IEC TS 63106-1:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SIMULATORS USED FOR TESTING OF PHOTOVOLTAIC POWER
CONVERSION EQUIPMENT – RECOMMENDATIONS –

Part 1: AC power simulators
FOREWORD
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Technical Specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 63106-1, which is a Technical Specification, has been prepared by IEC technical
committee 82: Solar photovoltaic energy systems.

The text of this Technical Specifications based on the following documents:
Draft TS Report on voting
82/1731/DTS 82/1776A/RVDTS
Full information on the voting for the approval of this Technical Specification can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 63106 series, published under the general title Simulators used for
testing of photovoltaic power conversion equipment – Recommendations, can be found on the
IEC web site.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC TS 63106-1:2020 © IEC 2020
INTRODUCTION
The objective of this document is to establish terminology, and create a framework for, and
provide guidance regarding the electrical performance of AC power simulators used to test
utility interactive photovoltaic (PV) power conversion equipment (PCE) for compliance with grid
interconnection standards.
It serves as a generalized guideline for the development of AC power simulators used within a
test and evaluation system for PV PCEs.
Testing laboratories are responsible for selecting the appropriate test items and procedures as
well as defining the required performance for adequate evaluation of utility interactive PV PCEs,
considering utility power requirements, local codes and regulations.
Utility interactive PCEs are used not only for PV, but also for various distributed generation
technologies such as wind power, battery energy storage, engine co-generation or fuel cells.
Some of the recommendations in this document may be similar and applicable for AC simulators
used to test these other generation technologies, but they are not intended to supersede testing
requirements found in related IEC standards.
This document may be used in conjunction with regional or national grid standards and codes,
such as:
a) European level utility interaction requirements such as:
EN 50549-1:2019,
EN 50549-2:2019.
b) German FGW TG3.
c) UL1741 supplement SA, SRD-UL-1741-SA-V1.1.
d) IEEE 1547-2003, IEEE1547a (Amendment 1) -2014 and IEEE1547.1-2005.
e) IEEE 1547-2018 and IEEE 1547.1-2020.

SIMULATORS USED FOR TESTING OF PHOTOVOLTAIC POWER
CONVERSION EQUIPMENT – RECOMMENDATIONS –

Part 1: AC power simulators
1 Scope
The purpose of this part of IEC 63106 is to provide recommendations for Low Voltage (LV) AC
power simulators used for testing utility interactive photovoltaic power conversion equipment
(PCE).
NOTE Low Voltage refers to 1 000 Va.c. and less.
The AC power simulators connect to the AC output power port of a PCE under test and simulate
the utility grid by generating comparable AC voltage.
The AC power simulators can be used to test a PCE’s utility interaction characteristics, including
protection, ride through, immunity and power quality. The requirements and procedures are
specified in IEC standards and local utility grid requirements, selected by the network operator,
utility, or authority having jurisdiction.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes recommendations of this document. For dated references, only the edition cited
applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 61000-4-7:2002, Electromagnetic compatibility (EMC) – Part 4-7: Testing and
measurement techniques – General guide on harmonics and interharmonics measurements
and :instrumentation, for power supply systems and equipment connected thereto
IEC 61000-4-7:2002/AMD1:2008
IEC TS 61836:2016, Solar photovoltaic energy systems – Terms, definitions and symbols
IEC TS 62910:2020, Utility-interconnected photovoltaic inverters – Test procedure for under
voltage ride-through measurements
IEC TS 63106-2, Simulators used for testing of photovoltaic power conversion equipment –
recommendations – Part 2: DC power simulators
IEC TS 63217:– , Utility-interconnected photovoltaic (PV) inverters – Test procedure of high-
voltage ride-through measurements
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in IEC TS 61836 and the
following apply.
___________
Under preparation. Stage at the time of publication: ACD.

– 8 – IEC TS 63106-1:2020 © IEC 2020
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
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• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
AC power simulator
system or device able to source and/or absorb AC power, for use in testing of PCE
Note 1 to entry: This document includes a real utility grid, where appropriate, as well as synthetic sources as
rotating machines or power converters.
3.2
power conversion equipment
PCE
electrical device converting one form of electrical power to another form of electrical power with
respect to voltage, current, frequency, phase and the number of phases
[SOURCE: IEC 62109-1:2010, 3.66]
3.3
port
particular interface of the PCE with external circuits
Note 1 to entry: see Figure 1 for examples of ports.

Figure 1 – Examples of ports
3.4
equipment under test
EUT
PCE that is tested by connecting and supplying DC and AC power to each port
3.5
AC output power port
port used to connect to a public low voltage AC mains power distribution network or other low
voltage AC mains installation
3.6
DC input power port
port used to connect the PCE to a low voltage DC photovoltaic power generating sub-system
3.7
distributed generation
DG
decentralized power generation system that is connected to the utility grid in a distributed
manner
3.8
low voltage
LV
set of voltage levels used for the distribution of electricity
[SOURCE: IEC 60050-601:1985, 601-01-26, modified to delete upper limit voltage]
3.9
high voltage
HV
set of upper voltage levels used in power system for bulk transmission of electricity
[SOURCE: IEC 60050-601:1985, 601-01-27]
3.10
medium voltage
MV
any set of voltage levels lying between low and high voltage
[SOURCE: IEC 60050-601:1985, 601-01-28]
3.11
type test
conformity test made on one or more items representative of the production
[SOURCE: IEC 60050-151:2001, 151-16-16]
3.12
OVRT
over voltage ride through for utility failure durability of operation
3.13
UVRT
under voltage ride through for utility failure durability of operation
3.14
OFRT
over frequency ride through for utility failure durability of operation
3.15
UFRT
under frequency ride through for utility failure durability of operation
3.16
ROCOF
rate of change of power system frequency in Hz/s in the transient period
4 PCE types with respect to AC voltage levels and grid interconnection
In this document, utility interconnected voltage or capacity categories are not specified. PCE
based DG may be connected to the utility in any of the voltage ranges described below:
a) High voltage transmission or sub-transmission line connection.
b) Medium voltage distribution line connection.
c) Low voltage distribution line connection, including PCEs for residential use and micro
inverter or module integrated electronics.

– 10 – IEC TS 63106-1:2020 © IEC 2020
Figure 2 shows examples of DG systems connected to the utility grid.

Figure 2 – Example of connection of DG systems to utility grid
Utility-interactive PCEs typically have AC voltage outputs in the range of 100 V to 1 000 V,
determined by the input DC voltage window of the PCE or the input voltage from a DC/DC
converter. Connections to the utility grid at higher voltages require the use of step-up
transformers. Therefore, an upper limit of 1 000 Va.c. for the AC voltage range of a PCE test
system is sufficient.
5 Test setup for utility interactive PCEs
5.1 General
In order to realize valid and reproducible testing, the AC power source shall be appropriate for
the test being performed. This may mean utilizing an actual power grid, an AC power generator
or an electronic AC power simulator depending on the needs of the specific test under
consideration. In this document, recommendations of AC power simulators for a wide range of
typical utility interconnection tests are described.
Similarly, the DC power source shall be appropriate for the test being performed. This may
mean utilizing an actual PV array output, a conventional power supply, or an electronic PV
power simulator depending on the needs of the specific test under consideration.
Recommendations for DC power simulators are addressed in IEC TS 63106-2.
NOTE Hardware in the loop (HIL) or software to control the voltage and frequency at the EUT output port point by
detecting output power (active and reactive) and calculating the voltage and frequency or phase properties by given
utility network model with simulated generators and line impedances are discussed and developed. They are not
used for type certification tests but still have potential usefulness in the future for testing the performance of multiple
DGs in combination with a smart grid.

5.2 Test setup examples for utility interaction test
5.2.1 General
The test system shall be able to simulate steady state and transient utility grid conditions with
respect to AC voltage, frequency, line impedance, load, and other conditions as required for
the testing. Figure 3 illustrates basic configuration examples for the EUT test system. Here,
EUT is the utility interactive PV PCE under test. A DC power simulator is connected to the DC
input power port. An AC power simulator is connected to the AC output power port, with other
optional impedance and load equipment.
Figure 3 shows only the main power line connections to DC port, AC port in both sides. An earth
line may be shared between DC side and AC side devices.

Figure 3 – Examples of fundamental setup of EUT test system
5.2.2 Types of AC power simulator systems
5.2.2.1 General
AC power simulator systems may consist of one or more of the following types of equipment: in
5.2.2 through 5.2.4. Other approaches are possible depending on the test(s) under
consideration. As different tests have different power simulator needs, it may be required or
optional for a facility to have more than one type of AC power simulator.
The internal resistance of an AC power simulator including connections to the EUT so measured
at the EUT AC output power port should be designed referring the real-world distribution and
transmission line impedance, for attaining the reasonable test result for power qualities, as
harmonics, DC injection, or flicker tests.

– 12 – IEC TS 63106-1:2020 © IEC 2020
5.2.2.2 Utility grid
A simple utility grid connection may be used for certain tests. The utility grid used shall have
the right nominal voltage and frequency, appropriate impedance and harmonic distortion levels,
and the ability to source or sink adequate active or reactive power for the test(s) under
consideration.
5.2.2.3 Utility grid and transformer with tap changer
A transformer with tap changer can change the output voltage of the AC power simulator but
only in discrete steps. Some types can be switched under load while others require the
transformer to be de-energized before switching. Quick transfer of voltage is realized by using
a semiconductor switch for the tap changer. Some types will cause a momentary loss of voltage
to the EUT while others do not. These characteristics need to be taken into account when
considering this technique for an AC power simulator.
5.2.2.4 Electronic AC power simulator
An electronic AC power simulator uses power electronics to create or modify AC grid voltage.
Electronic AC power simulators may be composed of an AC to DC conversion stage followed
by a DC to AC conversion stage. Other approaches such as waveform simulation with power
amplification are possible. Electronic AC power simulators provide a wide range of capabilities
for testing including continuous control of the output AC voltage, phase, and frequency. The
electronic AC power simulator provides testing voltage conditions for voltage swells (OVRT)
and sag (UVRT) on 1,2 or all 3 phases, and for some types, arbitrary waveform generation. The
electronic AC power simulator provides testing frequency conditions for frequency rise (OFRT)
and frequency drop (UFRT).
Electronic AC power simulators are typically categorized for three different product groups
based on size, including micro PCE, string PCE and central PCE. The fundamental output
characteristics of the electronic AC power simulators may depend on the testing power level
and the control of switching devices and circuits. For small scale PCE’s testing, linear power
amplification configurations are well-suited for precise output voltage control. For large scale
applications, chopper circuits with bi-directional control are typically used to reduce heat
dissipation. For a back-to-back system consisting of a chopper converter and inverter circuit
configuration, the output voltage harmonic distortion components are absorbed with sufficient
AC filter circuit.
5.2.2.5 Rotating engine and AC power generator
A rotating engine coupled to an AC power generator provides a controllable source isolated
from the utility grid. This provides a source independent of utility grid conditions and able to be
used at remote sites of PV installations in addition to laboratories. Motor-driven generator
systems are capable of continuous control of AC voltage and frequency. Such systems are
limited to creating only symmetrical variations (all three phases vary in the same manner).
5.2.3 Load
5.2.3.1 General
For some testing, it is required or important to control the impedance as seen by the EUT. This
can be inherent impedance of the AC power simulator, or additional local active or reactive
loads or line impedances may be needed.
5.2.3.2 Inherent impedance
All types of AC power simulators have an inherent impedance as seen by the EUT. This
impedance is complex and can impact the results of many types of grid interconnection testing.
It is important to characterize this impedance, and in some cases compensate for it or alter it
through external means.
5.2.3.3 RLC load
An RLC load is used in parallel to the EUT for:
a) Anti-islanding tests that require control over active and reactive power, load balance, and
the resonant load quality factor (Q-factor).
NOTE 1 RLC load details for anti-islanding can be found in standards such as IEC 62116 and IEEE 1547.1 .
NOTE 2 In addition to RLC loads, induction motors may be used as a load model. Such motors have tendency
to prevent frequency transition with power running and regeneration modes for anti-islanding tests.
NOTE 3 Electronic loads have the capability to simulate the passive RLC elements needed for anti-islanding
tests, and in some cases may be regenerative, thus reducing the power consumption of the test system. However,
the use of electronic loads in anti-islanding testing is not currently accepted by most standards.
b) Absorbing and dampening active and reactive power flow to the AC power simulator in case
it is not capable of absorbing reverse power flow from EUT.
5.2.4 Line impedance
A line impedance may be connected in series between the EUT and AC power simulator
depending on the need of the selected test. Examples of the purposes of the line impedance
are:
a) An impedance representing distribution line or transmission line inductance and resistance.
b) With by-passing or connecting the impedance in series to line, to make voltage fluctuations
at the AC output power port of the EUT intentionally for LVRT test.
c) A blocking impedance to prevent the direct application of surge test voltage to the AC power
source system, or to suppress short circuit current from the AC power source system to the
short circuit point, preventing system apparatus failure by surge voltage or short circuit
current.
6 General recommendations for AC power simulators
6.1 General
6.1.1 Overview
An AC power simulator is permitted to be used as the utility AC power source system. In this
clause, test items conducted with AC power simulators, and general recommendations relevant
to each of them are described.
All of the recommendations allow for variations based on need of the simulator.
6.1.2 AC main connections
The AC power simulator’s phase and neutral supply connections should be compatible with the
local country code and standards, and with the EUT.
6.1.3 Output transformer
The output transformer is supplied by EUT testing applicant to adjust AC output voltage, if
required.
6.1.4 Number of phases and voltage range
The AC power simulator provides the correct number of phases and conductors for the EUT.
The AC power simulator is able to operate across a voltage range that accommodates the UVRT
and OVRT tests required based on the nominal voltage of the EUT.

– 14 – IEC TS 63106-1:2020 © IEC 2020
For UVRT test, refer to IEC TS 62910:2020.
For OVRT test, refer to IEC TR 63217.
6.1.5 Frequency ranges supplied to EUT
Considering that PV PCEs are installed in all global regions, testing at both 50 Hz and 60 Hz is
desirable.
The AC power simulator shall be able to operate across a frequency range that accommodates
the OFRT and UFRT.OFRT tests based on the nominal frequency of the EUT.
6.1.6 Voltage stability and accuracy
The AC simulator shall be able to operate at voltage set points with an accuracy as specified
by the interconnection standards being tested.
The stability of the voltage may also be important for some tests and may be specified by the
test standards.
6.1.7 Frequency stability and accuracy
The AC power simulator shall be able to operate at frequency set points with an accuracy as
specified by the interconnection standards being tested.
The stability of the frequency may also be important for some tests and may be specified by the
test standards.
6.1.8 AC output voltage harmonic distortion
The typical AC output voltage harmonic distortion requirement is indicated in Table 1.
The interconnection standards may have different requirements.
The voltage harmonics are measured before the EUT is connected.
U1 is the fundamental component of the rated output voltage.
Table 1 – Typical maximum harmonic voltage distortion
(as per IEC 61000-4-7:2002)
Harmonic number % of U1
3 0,9
5 0,4
7 0,3
9 0,2
2 to 10 (even harmonics) 0,2
11 to 40 0,1
It is important to test the output power quality, see independent standards and documents per
each local requirement.
Total harmonic distortion value may also be specified by independent interconnection standards
for each region of power system.

6.1.9 Signal interface for hardware in the loop
As an optional function, an interface may be included to allow the AC power simulator to be
controlled by a Real Time Digital Simulator/Hardware in the Loop Simulator, so that testing
capabilities can be extended to specific voltage-frequency profiles or scenarios.
6.1.10 Durability against impulse test voltage
Surge voltage is induced to the AC output power port and DC input power port of the EUT during
normal rated or reduced power operation. The AC power simulator should be durable against
the impulse test voltages at the EUT AC output power port or DC input power port, either line
to line or line to ground.
NOTE Impulse voltage and wave forms may be referenced from standards such as IEC 61000-4-4, IEC 61000-4-5,
IEC 61643-11, IEEE C62.45, or IEEE C62.41.2.
6.1.11 Other requirements for test properties
6.1.11.1 General
The requirements shown below are to be confirmed for the test(s) under consideration.
6.1.11.2 AC phase-to-neutral voltage balance
The AC output phase-to-neutral voltage balance for a three-phase system is specified as per
test requirement.
6.1.11.3 AC output phase control range and accuracy
The AC phase timing accuracy of the change and recovery of voltage or frequency are specified
as per test requirement.
6.1.11.4 AC phase displacement to voltage balance
The AC output phase displacement to voltage balance is specified as per test requirement.
6.1.11.5 AC output voltage/frequency step change rate
The AC output voltage/frequency step change rate are specified as per test requirement.
6.2 AC power simulator performance and characteristics
Characteristics and performance of an AC power simulator are important for each specific test.
The desired characteristics are indicated in Table 2 through Table 23. Refer to local or national
grid connection codes for detailed specific requirements.
The characteristics recommended in Table 2 through Table 23 should be maintained over the
full range of conditions as applicable for the test specification.
NOTE 1 Test items for utility interactive PCEs are based on IEC TS 62786-1:2017, where requirements are
developed under close relationship with EN 50549 series. PCEs requirements for active and reactive power output
functions are developed reflecting the local utility experience and studies in UL1741SA, IEEE 1547.1, and FGW
PART3 (TG3) in parallel.
NOTE 2 Abbreviations used in the tables are: P for active power, Q for reactive power, S for apparent power, PF
for power factor, OV for over voltage, UV for under voltage, OF for over frequency, UF for under frequency, Iq for
reactive current and ROCOF for rate of change of frequency.

– 16 – IEC TS 63106-1:2020 © IEC 2020
Table 2 – Grid qualification/Requalification –
In-range voltage before connection/reconnection
Short description of test Before the EUT connection and injecting energy into the AC power
simulator, the AC voltage is raised or lowered from below or above the
interconnection voltage range threshold at which the EUT output switch
should close and then start generation. Typically, not required to be done
at full power and often signal injection methods are allowed.
Important AC power simulator Important aspects of the simulator attribute
attributes for this specific test
- RMS voltage continuously variable across a range that covers the
Variable AC voltage
interconnection voltage thresholds of all relevant standards, typically
requiring ± 20 % around V .
nom
- for interconnection voltage tests, need to be able to ramp V
rms
Steady frequency and phase - During the voltage ramps, the frequency and phase shall remain
unchanged.
Power - Simulator power may be signal level, or a small percentage of EUT
rated output, allowing a range of techniques.
Usability Capabilities and Drawbacks
benefits
AC utility grid None Voltage not variable
Utility grid and transformer None Voltage not variable
Utility grid, transformer, and tap Tap changer can do Interconnection voltage
Partial
changer step changes for testing with ramp or
interconnection voltage small steps is required.
testing.
Electronic AC power simulator Good Able to program Vrms
ramps and small step
changes, while holding
frequency and phase
steady.
For signal injection a
small simulator may be
used.
Rotating AC power generator Partial Able to control to Steadiness of frequency
create V ramps may be marginal.
rms
Unable to create defined
step changes.
Table 3 – Grid qualification/Requalification – In-range frequency before
connection/reconnection
Short description of test Before the EUT connection and injecting energy into the AC power
simulator, the AC frequency is raised or lowered from below or above the
interconnection frequency range threshold that the EUT output switch
should close and then start generation. Typically, not required to be done
at full power and often signal injection methods are allowed.
Important AC power simulator Important aspects of the simulator attribute
attributes for this specific test
- Frequency continuously variable across a range that covers the
Variable AC frequency
interconnection frequency thresholds of all relevant standards, typically
requiring ± 10 % around F .
nom
- for interconnection frequency tests, need to be able to ramp frequency.
Steady frequency and phase - During the frequency ramps, the voltage shall remain unchanged and no
phase jump.
Power - Simulator power may be signal level, or a small percentage of EUT
rated output, allowing a range of techniques.
Usability Capabilities and Drawbacks
benefits
AC utility grid None Frequency not variable
Utility grid and transformer None Frequency not variable
Utility grid, transformer, and tap None Frequency not variable
changer
Electronic AC power simulator Good Able to program
frequency ramps and
small step changes,
while holding voltage
steady.
For signal injection a
small simulator may be
used.
Rotating AC power generator Partial Able to control to Steadiness of voltage
create frequency may be marginal.
ramps
Unable to create defined
small step changes.
– 18 – IEC TS 63106-1:2020 © IEC 2020
Table 4 – Power capability: Nameplate P, Q, S under normal
and near-normal grid conditions
Short description of test After the connection to the AC power simulator, the EUT input is raised to
the rated maximum power point of the PV array to check that the EUT is
operating at rated output active power under normal and near-normal grid
conditions. EUT operation set point or grid voltage is adjusted, to check
that the EUT is operating at rated output reactive and apparent power as
designed.
Important AC power simulator Important aspects of the simulator attribute
attributes for this specific test
Steady AC voltage - During the power capability tests, the voltage shall remain unchanged.
- For voltage deviation to reactive power tests, need to be able to adjust
voltage.
Steady frequency and phase - During the power capability tests, the frequency and phase shall remain
unchanged.
Power - Simulator power shall cover EUT active, reactive and apparent power
rating. The power is injected into the AC power simulator or consumed
by parallel loads, allowing a range of techniques.
Usability Capabilities and Drawbacks
benefits
AC utility grid Partial Able to absorb the Voltage not variable
active and reactive
power.
Utility grid and transformer Partial Able to absorb the Voltage not variable
active and reactive
power.
Utility grid, transformer, and tap Good Able to absorb the Voltage tap adjustment
changer active and reactive to the setpoint is needed
power. for the voltage change
by reactive current with
Voltage variable.
the transformer
impedance.
Electronic AC power simulator Good Able to program the The power is absorbed
voltage steadily. into the AC power
simulator or consumed
by parallel loads
Rotating AC power generator Partial Able to adjust voltage. Voltage adjustment for
voltage rise by reactive
current and AC power
generator impedance is
needed.
The power is absorbed
into the AC power
generator or consumed
by parallel loads
Table 5 – Power capability: Limitation of P/Q/S/PF by setpoint
Short description of test After the connection to the AC power simulator, the EUT input is raised to
the rated maximum power point of photovoltaic array to check that the
EUT is operating at limited set point output P under normal and near-
normal grid conditions. EUT operation set point is adjusted, to check that
the EUT is operating at rated output reactive, apparent power and power
factor as designed. Sometimes, photovoltaic array I-V curve has a
maximum power point exceeding the EUT rated input power. In that case,
EUT is checked to operate at rated output power.
Important AC power simulator Important aspects of the simulator attribute
attributes for this specific test
Steady AC voltage - During the limitation by setpoint- tests, the voltage shall remain
unchanged.
- For voltage deviation to reactive power under the setpoint tests, need to
be able to adjust voltage.
Steady frequency and phase - During the limitation by setpoint- tests, the frequency and phase shall
remain unchanged.
Power - Simulator power shall cover EUT active, reactive and apparent power
rating. The power is injected into the AC power simulator or consumed
by parallel loads, allowing a range of techniques.
Usability Capabilities and Drawbacks
benefits
AC utility grid Partial Able to absorb the Voltage not variable
active and reactiv
...