Tackling Challenges of Higher Power in E-Mobility

In 1888, the motoring world enthusiastically welcomed one of the first patented electric vehicles (EV) designed by chemist William Morrison. It was a 4-horsepower carriage, sporting 24 rechargeable batteries, and a top speed of 20 mph.

Illustration of the original definition of "Horsepower" as coined by James Watt in the late 18th century. CC BY-SA 3.0

Fast-forward to today, the EV market still uses horsepower – the hp unit – as car buyers are more familiar with this term, versus figuring out how powerful the electric motor is in terms of kilowatts (kW). More precisely, the EV industry uses ‘brake horsepower’ to account for power loss due to friction.

Our electric cars today have Herculean horsepower compared to their forefathers chugging along with 4 hp. Typical family cars like the Nissan LEAF SV offer over 147 hp, while the EV start-up utilitarian Rivian RiT EV truck is set to deliver a whopping 754 hp.

A few technology trends are emerging to support the need for greater EV power: \

  1. Larger batteries \
  2. Plug and charge facilities\
  3. Intelligent load management and bidirectional charging

    Larger batteries
    Larger capacity batteries address and assuage the issue of range anxiety. Consumers are also demanding faster charging facilities, a reason behind the growth in Level 3 ultra-high-power charging, also known as DC fast charging. DC Fast Charging can bring an EV’s battery back up to 80 percent of its capacity anywhere from within 30 to 60 minutes.

    Plug and charge facilities
    Emerging plug and charge technology at publicly-accessible premises such as offices and malls will make it very convenient for EV drivers to top up their battery charge. New EV supply equipment (EVSE) rollouts come with automated connecting devices, removing the need to authorize payment, or even plug in the charging connector.

    Intelligent load management and bidirectional charging
    Intelligent load management and bidirectional charging are helping to enable a truly smart grid, contributing towards environmental health and economic benefits. Advanced charging protocols and home energy management systems (HEMS) allow optimal timing for charging an EV or HEMS battery, or returning energy to the grid. With the broader energy ecosystem comprising smart meters and renewable energy sources, the grid can be balanced.

Tackling High-Power Challenges
Conformance standards play an important role in ensuring proper communication between the EVSE and the EV, physical plug design, power flow, and numerous test scenarios. However, for EV and EVSE OEMs, the mix of new technologies and evolving standards present fresh challenges, as each brand tries to sell into different global markets with non-homogenous charging standards.

For instance, the same car maker with global market penetration will need to ensure each new model can meet the American and European charging standard CCS, the Chinese GB/T, the Japanese CHAdeMO, and soon, the new Asian standard – ChaoJi.

Many OEMs are leveraging emulation test technology as a practical approach to validate their products. As an example, some manufacturers are using Keysight’s SL1047A Scienlab Charging Discovery System –High-Power Series to emulate different high-power EV and EVSE use cases, and meet global charging standards and norms, such as:

• AC charging mode according to IEC 61851-1, SAE J1772, GB/T 18487.1 and ISO 15118
• DC fast charging mode according to DIN SPEC 70121, ISO 15118, GB/T 27930 and CHAdeMO

EV and EVSE OEMs also need to tackle other challenges, such as managing the cost of operating a high-power design and test environment. Some manufacturers have adopted the SL1200A Series Scienlab Regenerative AC Emulator, which can act as a high-power 3-phase AC and DC power source; up to 1200 VL-L, and 130 A. The 100% regenerative (bidirectional) power from the SL1200A can be returned to the grid with > 85% efficiency. This drastically reduces the amount of dissipated heat and saves money on the air-conditioning cooling costs for the test lab.

In the world of e-mobility, consumers are likely to desire EVs with higher horsepower, longer ranges, and faster charging facilities. New design and test technologies will continue to help EV and EVSE manufacturers to meet these demands, and be commercially viable in the long run.