High voltage EV components are frequently exposed to variations in their supply voltage that occur during different driving conditions (accelerating, braking, battery SOC etc.). It is therefore necessary to test that HV components continue to function correctly under different supply voltages. This includes voltage changes (slow changing voltage ramps) as well as voltage dynamics (dynamic slopes and pulses).
The test setup is relatively simple with “just” a DC source as a dynamic battery simulator which supplies the EUT (plus some measurement devices to monitor the voltage and current):
ISO 21498, LV123, VW 80300 and other standards define various tests for voltage changes and voltage dynamics:
While the shape of the waveforms looks relatively simple, the difficulty lies in the rising and falling slopes. While voltage variations have slew rates (du/dt) in the range of 2V/s and 2000V/s, the voltage dynamics i.e. load dump require slew rates of 250V/ms and higher.
The table shows examples of rise times depending on the system voltage and slew rates:
| Rise time (0 – 100%) | System voltage | ||
| Slew rates | 400V | 800V | |
| 2 V/s | 200 s | 800 s | |
| 200 V /s | 2 s | 4 s | |
| 250’000 V/s | 1.6 ms | 3.2 ms | |
High voltage sources that are typically used in e-drive and battery test benches are optimized for precision, stability and cost. The downside of these sources is the limited dynamic of the output. While slower voltage changes are usually possible to generate, the fast voltage dynamics are out of their operating range.
To deliver the required high output dynamic of 500 V/ms or higher, a source designed to match the characteristics of the application is needed. This guarantees to reproduce exactly the required waveform – without over- or undershoot.
Below you can see an oscilloscope trace of a voltage profile 0 – 1000V with 1000V/ms slew rate (generated by PowerWave) - Note: the rise time is measured 10 – 90%
Special focus on high output slew rates is important when choosing a power source for testing drives and batteries according ISO 21498, LV123 and similar standards. AMETEK CTS NetWave and PowerWave are sources specifically designed and optimized to perform the range of demanding dynamic voltage tests.
MCS Test are an approved UK partner for Ametek CTS
Content Source: THE CHALLENGE OF VOLTAGE VARIATION TESTING (ametek-cts.com)
250 kVA/kW, upgradeable to 1 MVA/1MW
PowerWave is a high power, electronically controlled power sources suitable for applications where exceptional performance is required. Electric Vehicle testing according ECE R10 PowerWave is the ideal source to supply your EMC chamber and conducted test area with the power that is needed. It combines AC and DC in a compact footprint and allows charging in Mode 3 (AC) and Mode 4 (DC).
Output Power up to 7,500 VAAC and 9,000 WDC
NetWave - Simulation of the most required power supply phenomenon The NetWave series (1-phase) are single phase AC/DC power sources, specifically designed to meet the requirements as per the standards IEC/EN 61000-4-13, -4-14 and -4-28.
Output Power up to 7,500 VAAC and 9,000 WDC
NetWave - Simulation of the most required power supply phenomenon The NetWave series (1-phase) are single phase AC/DC power sources, specifically designed to meet the requirements as per the standards IEC/EN 61000-4-13, -4-14 and -4-28.
Wide Power Bandwidth; DC - 5 kHz
NetWave - Simulation of the most required power supply phenomenon The NetWave Series (3-phase) are three-phase AC/DC power source, specifically designed to fully meet the requirements as per the standards IEC/EN 61000-4-13, -4-14, -4-28 and in addition to pre compliance testing to -4-27.
Output Power up to 270 kVA AC / 324 kW DC
NetWave - Simulation of the most required power supply phenomenon The NetWave Series (3-phase) are three-phase AC/DC power source, specifically designed to fully meet the requirements as per the standards IEC/EN 61000-4-13, -4-14, -4-28 and in addition to pre compliance testing to -4-27.
Output Power up to 270 kVA AC/324 kW DC
NetWave - Simulation of the most required power supply phenomenon The NetWave Series (3-phase) are three-phase AC/DC power source, specifically designed to fully meet the requirements as per the standards IEC/EN 61000-4-13, -4-14, -4-28 and in addition to pre compliance testing to -4-27.
AMETEK CTS is pleased to announce the release of the New Ripple NX, a high-power ripple generator designed to perform ripple immunity tests.
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Ripple is a disturbance signal that is superimposed on a supply line. Typically, it originates from switching of power electronics i.e. MOSFETs or IGBTs. On an electric vehicle the biggest source for ripple is the electric propulsion system, namely the inverter part.
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Ripple testing might seem to be like an easy to perform test – but the devil lies in the detail. The biggest challenge is how to reach the required ripple voltage levels at the EUT terminals. And this depends heavily on the impedance of the component.
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