E-Mobility: Innovative Design & Test Solutions for the Electric Powertrain and HEV / EV Ecosystem

Keysight’s Global Automotive & Energy Footprint

Keysight’s global footprint ensures we deliver solutions where you need them. We have established automotive customer centers in Michigan, United States, Böblingen, Germany, Nagoya, Japan, and Shanghai, China. These centers underscore our commitment to work with and serve customers in local proximity to support innovative technology projects that drive the automotive and energy industries. We maintain partnerships with international organizations that help set the standards for electromobility (e-mobility). This translates into future-ready solutions for your automotive design and testing requirements.

What Is Fueling the E-Mobility Ecosystem?

The number of pure electric vehicles (EVs) and hybrid electric vehicles (HEVs) on the world’s roads will hit 250 million by 2030, the International Energy Agency forecasts. That is a big leap from the IEA’s 5.1 million reported for such vehicles in 2018. This growth is matched by advances in technologies for powertrains, power electronics, cells and batteries, and the charging infrastructure (Figure 1). Manufacturers must ensure their EV fleets comply with CO2 emission regulations. They also need to improve energy efficiency and range. It typically takes more than one design cycle before new powertrain technology turns a profit. The cost pressure on EV powertrain components (traction motors, converters, power converters, and batteries) continues to drive new fundamental technologies. These technologies drive demand for design and test solutions that can provide better emulation and test coverage to comply with safety and performance standards. Growth in the plug-in vehicle market is also fueling new technologies in the adjacent renewable energy ecosystem. These include photovoltaic (PV) inverter and smart grid technologies.

Testing in the High-Power E-Mobility Environment

Bidirectional test: Testing bidirectional power flow demands equipment that can source and sink power to the converter. Conventional test methods use external circuits and multiple instruments. These methods typically do not allow for smooth signal transitions between sourcing and sinking power, resulting in inaccurate simulations of operating conditions. They also lead to heat build-up in the test environment, requiring costly cooling measures.

New power semiconductor technology: Designers are starting to use wide bandgap (WBG) devices. These offer better power efficiency and the ability to handle higher voltages and temperatures than conventional silicon devices. However, their use complicates the simulation and design of DC-to-DC converters. Traditional simulation tools used in the design of power converters do not accurately capture the behavior of WBG devices and cannot support optimal design of converters using these devices. Designing today’s converters requires new simulation and test technologies.

Safety and reliability concerns: Using new semiconductors requires extra validation and reliability testing to ensure converters will last under harsh operating conditions. Given the power levels used with converters, designers need to be careful when testing them. This requires special safety mechanisms in manufacturing, including redundant systems that do not expose personnel and equipment to high voltages if a failure occurs.

Maximizing efficiency: It is difficult for testers to simulate all of the operational and environmental influences on efficiency to evaluate the real-world, whole-system operation of the converter. Measuring small percentage changes in efficiency demands instruments with high dynamic range.

Test Solutions for Electric Vehicles and Power

To address these emerging design and test issues, Keysight has created and introduced innovative approaches to help developers and manufacturers accelerate their programs. This e-mobility brochure will provide you with an overview of the design and test solutions and services that Keysight offers in this ecosystem:

Electric powertrain testing: Ensure energy efficiency at the power semiconductor level, through inverter and DC-to-DC converter testing for onboard systems, as well as cell characterization and power efficiency tests for battery modules and packs, while addressing safety, time, and cost concerns.

Charging technology and infrastructure testing: Test the EV and electric vehicle supply equipment (EVSE) charging interfaces in the field or laboratory, from mobile use to comprehensive applications.

Energy ecosystem testing: Use leading-edge emulation technology and software, spanning solar cell testing to PV inverter efficiency testing, to help meet stringent industry standards for safety and performance.

Electric Powertrain Testing

HEVs and EVs have multiple architectural variations

For the strong (or parallel) hybrid and the pure EV (no engine), a high-voltage (HV) bus supplied by a large battery drives the electric powertrain (Figure 2). Power levels of the inverter and motor/generator range from ~ 60 kW to more than 180 kW. Along with the large lithium-ion (Li-ion) battery, development of these architectures requires a significant investment. Most of the components are bidirectional, allowing power to go from the battery to the inverter, which turns the motor and moves the vehicle (traction drive). When decelerating, the momentum of the vehicle turns the generator, driving power back through the inverter and charging the battery (regenerative braking). Each step of this powertrain requires thorough testing to maximize energy efficiency for the HEV/EV.

In the mild hybrid (MH), the motor/generator, inverter, and battery are also bidirectional. They are not large enough to drive the vehicle by themselves (as in the HEV or EV). Instead, they supplement the engine power during acceleration and recharge the battery during deceleration. The voltage level for MHs is typically 48 V, keeping the bus structure under the 60 V safety rating for HEVs. That provides four times the potential power of the 12 V bus with the same current rating (Figure 3). Each component and step of these powertrain systems requires full testing to maximize energy efficiency in the conversion process. The design and manufacturing phases must account for cohesive functionality of each component and subsystem, as well as safety considerations.

Inverter test

Inverters are essential components for numerous applications because they convert electrical voltage bidirectionally. Traction inverters convert DC voltage from a battery to AC voltage for an electric machine. This functionality makes inverters an important component in electromobility, as well as numerous industrial applications. Quality, durability, and safety requirements are demanding in the automotive sector. All components are subject to stringent testing throughout development and production. The earlier tests can be performed during the development phase, the more efficient the next steps are. Comprehensive test scenarios and independent component testing can reduce development expenses and speed innovation (Figure 4). To emulate the inverter environment, replace the battery with a Scienlab Dynamic DC Emulator from Keysight. Replace the electric machine with a Scienlab Machine Emulator.