IEC TR 61000-2-15:2023
(Main)Electromagnetic compatibility - Part 2-15: Description of the characteristics of networks with high penetration of power electronic converters
Electromagnetic compatibility - Part 2-15: Description of the characteristics of networks with high penetration of power electronic converters
IEC TR 61000-2-15: 2023 which is a Technical Report, addresses in particular the following main phenomena, which affect the power quality in modern distribution systems with high penetration of power electronics converters. As some aspects of the subject have already been addressed in the past, considering the evolution of the LV and MV networks, this document focuses on the following aspects:
resonances in the network, modelling and on-site validation;
supraharmonics and measurements issues;
impact of increased number of power electronic converters;
stability and instability issues for the equipment to be connected
The target phenomena and conditions of this document are the following:
frequency: ≤ 2 kHz, 2 kHz to 9 kHz, ≥ 9 kHz;
voltage levels: LV, MV;
harmonic sources: all types of converters (EV battery chargers, appliances, etc.…).
Some of these frequency ranges have already been standardized in some countries (Japan, Germany, Switzerland, etc.), but the resulting phenomena developed will benefit being described in more details, with a focus on the interaction between the converters and the electrical networks. The case of the presence of a large number of converters is also at stake. Some complex phenomena can also arise when the full system is not stable anymore. NOTE Whereas it is expected that the models and derived calculations form this document can be applied to the Americas electrical systems its formal validation studies are still pending.
General Information
Standards Content (Sample)
IEC TR 61000-2-15
®
Edition 1.0 2023-02
TECHNICAL
REPORT
colour
inside
Electromagnetic compatibility –
Part 2-15: Description of the characteristics of networks with high penetration of
power electronic converters
IEC TR 61000-2-15:2023-02(en)
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IEC TR 61000-2-15
®
Edition 1.0 2023-02
TECHNICAL
REPORT
colour
inside
Electromagnetic compatibility –
Part 2-15: Description of the characteristics of networks with high penetration of
power electronic converters
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01; 33.100.01 ISBN 978-2-8322-6550-5
Warning! Make sure that you obtained this publication from an authorized distributor.
® Registered trademark of the International Electrotechnical Commission
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– 2 – IEC TR 61000-2-15:2023 IEC 2023
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 11
4 Resonance phenomena with network and power electronics equipment based on
actual cases . 12
4.1 Operation of overvoltage protection of earth leakage circuit breaker in
Japanese LV systems . 12
4.1.1 General . 12
4.1.2 Circuit modelling . 13
4.1.3 Measurements on site. 14
4.1.4 Technical or regulatory aspects . 16
4.2 Analysis and modelling of an EV charging hub with PV production . 17
4.3 Impact of power electronic household equipment on the impedance
characteristics in residential networks . 21
4.4 Harmonic resonance in an urban, residential low voltage grid . 25
4.5 Harmonic distortion and impedance characteristics in an islanded microgrid . 28
5 Impact of modern power electronics on the propagation and amplification of
voltage distortion . 31
5.1 Harmonic propagation in a residential LV network . 31
5.1.1 General . 31
5.1.2 Measurements . 31
5.1.3 Modelling issues . 33
5.2 Supraharmonic amplification in a residential LV network with a fast charging
station . 34
5.2.1 Measurement procedures . 34
5.2.2 Measurement results . 36
5.2.3 Simulation results . 39
5.3 Supraharmonic amplification in a residential low voltage network with PV
converters . 41
5.4 Generic supraharmonic emission models for PWM based converters . 42
5.5 Assessment of optimal impedance angles for power electronic devices to
minimize risk of amplification . 43
6 Cases of a large amount of converters . 47
6.1 General . 47
6.2 Large PV installations . 48
6.3 Industrial grids . 53
6.4 Multiple EV chargers in a central charging infrastructure . 57
6.4.1 General . 57
6.4.2 Measurements . 58
6.4.3 Modelling of interactions between N similar single-phase power
converters . 59
7 Impact of grid conditions on the operation of converters . 66
7.1 Analysis of a single-phase inverter model with an LCL filter using the
Nyquist criterion . 66
7.2 Probabilistic stability analysis for commercial low power inverters based on
measured grid impedances . 74
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IEC TR 61000-2-15:2023 IEC 2023 – 3 –
7.3 Description of electric vehicles connected to a weak network . 77
7.3.1 General . 77
7.3.2 Modeling of the equipment involved . 77
7.3.3 Determination of the voltage at the entrance of the charger, for different
impedance values of the upstream network . 79
7.3.4 Measurements performed at the manufacturer’s laboratory . 81
7.4 Other interactions between the grid and power converters . 82
7.4.1 PV connected to a weak network . 82
7.4.2 Windfarms connected to a grid . 88
7.4.3 Microgrid during the islanding phase. 89
7.4.4 Impact of the operating conditions . 93
8 Harmonic emission characteristics of power electronic equipment for the mass-
market . 94
9 Conclusion and perspectives . 97
9.1 General . 97
9.2 Challenges . 97
9.3 Main findings . 98
9.4 Consequences . 98
9.5 Recommendations . 99
9.6 Future work . 99
Bibliography . 100
Figure 1 – Schematic illustration of a harmonic resonance issue in a LV system . 12
Figure 2 – Waveform of the overvoltage at the neighbour side . 13
Figure 3 – Description of an equivalent circuit modelling for harmonic resonances. 13
Figure 4 – Electrical circuit used in simulations, and results of resonance magnification
factors (RMFs) . 14
Figure 5 – Description of the experimental test configuration . 14
Figure 6 – Measurement performed during the experimental tests . 15
Figure 7 – Resonance magnification factors (RMFs) using measurement and
simulation . 15
Figure 8 – Flowchart to assess an appliance’s compliance with JIS TS C 0058 [2] . 16
Figure 9 – Harmonic current limits for measurement assessment . 17
Figure 10 – Trends of the number of inquiries regarding current emission limits in
Japan . 17
Figure 11 – Bloc scheme of the measured EV charging hub with PV production . 18
Figure 12 – Power line impedance magnitude (top) and phase (bottom) measured at
the point of common connecting (PCC) of an EV charger hub with PV production . 19
Figure 13 – Resulting simplified model of the charging hub with distribution lines and
feeder . 19
Figure 14 – Impact of a super-fast EV charger on grid impedance . 20
Figure 15 – Impedance characteristics of an urban LV network, . 24
Figure 16 – Schema of the network . 25
Figure 17 – Network harmonic impedance measured at different locations (L1-N) . 26
Figure 18 – Simulated network harmonic impedance at different locations (L1-N) using
default element representations . 26
Figure 19 – Equivalent impedance model of a domestic customer . 27
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Figure 20 – Measured and simulated network harmonic impedance at different
locations (L1-N) using the developed customer impedance model. 27
Figure 21 – Schematic representation of system under test . 28
Figure 22 – Impedance characteristics (magnitude and phase angle) . 29
Figure 23 – Voltage harmonic levels in ICM (a) and ISM (b) . 30
Figure 24 – Simplified line diagram of the grid with marked measuring points . 31
Figure 25 – Connection of a PQ measuring device . 32
th
Figure 26 – Measured 15 current and voltage harmonic on phase L1 during operation
of the heat pumps at the heat pumps’ point of connection without active filter . 32
th
Figure 27 – Measured voltage amplitudes of the 15 harmonic for each phase L1 to L3
during three different operating states without active filter . 33
th
Figure 28 – Comparison of measured and simulated voltage levels (15 harmonic
voltage) at each measuring point . 33
th
Figure 29 – Modelled voltage vectors of the 15 harmonic at on- and off-state of the
large heat pump without active filtering . 34
Figure 30 – Spectrogram of the voltage at the point of injection of supraharmonic
currents in a residential low voltage network . 35
Figure 31 – Single-line diagram of relevant parts of the low voltage network . 36
Figure 32 – Transfer ratio of supraharmonic voltage along the low voltage cable for
phase L1 in case of single-phase injection at the transformer busbar BB . 37
Figure 33 – Crosstalk ratio of supraharmonic voltage between phase L1 (phase of
injection) and phase L2 at the junction box JB . 38
Figure 34 – Measured impedance (magnitude and phase) of the DC charger in idle
mode . 38
Figure 35 – Transfer ratio along the cable for all three phases in case of three-phase
injection at the transformer busbar BB . 39
Figure 36 – Fully coupled three-phase simulation model . 39
Figure 37 – Simplified simulation model for supraharmonic transmission along a low
voltage cable . 40
Figure 38 – Comparison of measured and simulated transfer ratios along a low voltage
cable. 40
Figure 39 – Transfer ratio of supraharmonic voltages along a low voltage cable of
varying length . 41
Figure 40 – Single-line diagram of the analysed low voltage network, two routes, and
measurement locations on each route in red, green and blue . 41
Figure 41 – Transfer ratios along two routes in a low voltage network with residential
customers, upstream direction as circles, downstream direction as crosses . 42
Figure 42 – Equivalent circuit (model) for the supraharmonic emission of single-phase
th
voltage-source power converters for the m emission band . 43
Figure 43 – RMS voltage spectrum U at the output terminals of a single-phase power
S
converter H-bridge using unipolar PWM . 43
Figure 44 – Amplification and damping of supraharmonic emission at the POC
relatively to the source voltage depending on the network to source impedance . 45
Figure 45 – Circles of constant POC voltage in the dominant emission band of two
photovoltaic inverters [29] . 46
Figure 46 – Prevailing phase angle of 187 measured network loop impedances
[34]between 2 kHz and 150 kHz, phase angle of the line impedance stabilization
network from CISPR 16-1-2 . 46
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IEC TR 61000-2-15:2023 IEC 2023 – 5 –
Figure 47 – Cumulative distribution function (CDF) of non-intentional emissions due to
distributed energy sources at two different frequencies (45,7 kHz and 118,4 kHz) and
noise present in the electrical grid (122,9 kHz) . 47
Figure 48 – Identification of the frequencies in the frequency response. 47
Figure 49 – Identification of the frequencies in the spectrogram of the measurements
(see case study [23]) . 48
Figure 50 – Parallel-connect configuration in large photovoltaic (PV) farm . 49
Figure 51 – Simplified parallel of two converters featuring LCL filter and capacitor on
common bus for reactive compensation in the grid (see Table 7) . 49
Figure 52 – Frequency domain results of parallel LCL filter system with reactive power
compensation capacitor represented in two frequency ranges . 50
Figure 53 – N parallel connected equivalent inverter models equipped with LCL filter
interfaces connected to common grid impedance 𝐙𝐙 as parallel connection of
g
Thévenin’s equivalent voltage sources and equivalent impedances . 51
Figure 54 – Change in Bode plot of i /i (ratio of grid and inverter side currents
sg s11
respectively) or LCL-filter topology when the number of parallel connected inverters n
increases from 2 to 8 with increments of 2 . 51
Figure 55 – Time domain simulations of parallel LCL system without reactive power
compensation capacitor dependent on (in dependency of) a small sinusoidal
disturbance term added in the control loop – Duty cycle . 51
Figure 56 – Power line impedance in lower frequency range measured with 0 to 59
inverters activated in a 2,1 MW PV plant . 52
Figure 57 – Power line impedance measured with 0 to 59 inverters activated in a 2,1
MW PV plant . 53
Figure 58 – Configuration of an industrial grid . 54
Figure 59 – Interaction between two converters, which can lead to resonances and
generate non-intentional emissions in the 2 kHz to 150 kHz frequency range. 54
Figure 60 – Modeling of a simple configuration of noise source and noise sink, where
nd rd th
the EMI filter of the sink converter can be of 2 , 3 or 4 order [25] . 55
Figure 61 – Impedance into the noise sink converter Z with different EMI filter
sink
types with simple choke interface only and different EMI filter configurations . 55
Figure 62 – Impedance into the noise sink converter Z with different EMI filter
sink
types with LCL interface and different EMI filter configurations . 56
Figure 63 – Ratio of voltage and current in phase 1 with a third-order EMI filter and
different cables with: a) DM excitation and b) CM excitation . 57
Figure 64 – Voltage at 10 kHz of one to four BEVs charging at a common POC, time
varying values as solid line (20 ms measurement windows), overall RMS as dotted line . 58
Figure 65 – Supraharmonic voltages and currents at the POC of multiple AC charging
points, first emission band (800 Hz) centred around 10 kHz . 59
Figure 66 – Single-line diagram of an arbitrary number N of power converters operating
in parallel on a single network phase . 60
Figure 67 – Supraharmonic emission model for an arbitrary number N of power
converters operating in parallel . 60
Figure 68 – Simulation of supraharmonic beating using summation of rotating phasors,
for one up to three sources with different frequencies and magnitudes of contribution,
first emission band . 61
Figure 69 – Exemplary assessment of the supraharmonic emission of two photovoltaic
inverters using the criteria in Formula (19) to Formula (21), and photovoltaic inverters
from [15] . 64
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Figure 70 – Dependency of the POC voltage on the number of sources N for different
magnitude ratios of source impedance to network impedance assuming phase angles
of source impedance and network impedance are equal . 65
Figure 71 – Single phase inverter with an LCL filter and corresponding state variables . 66
Figure 72 – Block scheme equivalent to the formula system of Figure 71 . 67
Figure 73 – Linearized control loop for the in-feed converter and transfer functions for
feed forward and current measurement filter . 68
Figure 74 – Norton equivalent circuit of the single-phase inverter . 69
Figure 75 – Nyquist stability analysis of the control loop with parameters listed in Table 8 . 70
Figure 76 – PLECS model of the single-phase inverter with LCL filter . 71
Figure 77 – PLECS model of the single-phase inverter controller with Feedforward of
the connecting point voltage . 71
Figure 78 – Simulation result of a current reference step of 0 A to 10 A for the
converter . 72
Figure 79 – Impedance magnitude (a) and phase angle characteristic (b) of
commercially available single-phase inverter (black), network impedance with
inductance of 2,3 mH (blue) and 3,2 mH (red) . 73
Figure 80 – Grid-side current measurements for LR-equivalent network impedance with
inductance values of 2,3 mH (a) and 3,2 mH (b) . 74
Figure 81 – Small signal model of an inverter and the low voltage network . 74
Figure 82 – Magnitude (a) and phase angle of low voltage network impedance
measurements at 120 measurement sites . 75
Figure 83 – Magnitude (a) and phase angle of the impedance of six commercially
available inverters . 75
Figure 84 – Critical frequency regions of commercially available inverters (a) and
measurement sites in LV networks (b) . 76
Figure 85 – Electrical network including the network and four electrical vehicles
connected (described in the EMTP program) . 77
Figure 86 – Description of the different elements considered . 78
Figure 87 – Description of the filter connecting the boost to the electrical network . 78
Figure 88 – Description of the low frequency filter . 78
Figure 89 – Description of the converter of the boost PFC converter, including its
AC/DC rectifier. 79
Figure 90 – Current i flowing in the electronic components (diodes, IGBTs) versus
d
positive values of the applied voltage V . 79
d
Figure 91 – Voltage V at the entrance of the charger, obtained by simulations, for
c
different values of the upstream network . 80
Figure 92 – Description of the phase-space diagram corresponding to the main state-
variables of the system . 80
Figure 93 – Current crossing an IGBT obtained by simulations, with an inductance
value of 600 µH for the upstream network . 81
Figure 94 – Voltage V at the entrance of the charger, measured at the
cmeas
manufacturer’s laboratory, for a value of 750 μH for the inductance of the upstream
network . 81
Figure 95 – Description of the circuit including a solar PV–micro turbine based power
system with battery backup . 83
Figure 96 – PCC (grid) voltage with linear and non-linear loads in the absence of any
VSI (voltage source inverter). 83
Figure 97 – Grid working and VSI switched on at t = 0,5 s . 84
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IEC TR 61000-2-15:2023 IEC 2023 – 7 –
Figure 98 – Grid working and VSI switched on at t = 0,5 s . 85
Figure 99 – Frequency characteristic of the 3 kW PV system with L-C-L filter in the
following grid conditions: A) 0,1 mH, B) 3 mH, C) 0,1 mH, 100 μF and D) 3 mH, 100 μF . 85
Figure 100 – Resonance frequency variation in per cent of the rated resonance
frequency as a function of grid inductance in per cent . 86
Figure 101 – Illustration of a quasi-periodic route to chaos in a buck-boost converter,
...
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