What you'll learn:
- Comparing the powertrain vs. an E-Axle.
- Details of the Renesas-Nidec "8-in-1" PoC that uses a single MCU.
- Components used in the E-Axle PoC.
The electric-drive axle (E-Axle) is responsible for converting the electrical energy provided by the battery pack into mechanical energy to propel an electric vehicle (EV) forward, using an electric motor as the main power source. A standard powertrain is made up of an engine (or an electric motor for fuel-cell EVs or battery EVs), transmission, driveshaft, differential, and axles.
On the other hand, an E-Axle is a drive unit that integrates into an axle structure the main components necessary to propel the vehicle. An E-Axle combines a drive motor, a gear, and an inverter. By integrating these multiple functions, the E-Axle system can reduce system size and weight, simplifying EV design.
What Does “8-in-1” Mean?
Renesas Electronics announced the world's first “8-in-1” proof of concept (PoC) for EV E-Axle systems. It controls eight functions using a single microcontroller (MCU). Developed in collaboration with Nidec, this PoC integrates a motor, gear (reduction gear), inverter, DC-DC converter, and on-board battery charger (OBC).
According to Renesas, system-level testing has been completed to ensure its performance. The company will showcase a live demonstration of the new E-Axle design at electronica 2024 in Munich, Germany, November 12-15 (Hall B4, Stand 179).
Renesas provided key components, including semiconductors and a reference design for the new 8-in-1 E-Axle system. It also plans to deliver turnkey semiconductor solutions for various X-in-1 systems based on the reference design verified through this PoC. Armed with these solutions, developers can implement and evaluate X-in-1 systems quickly, accelerating EV development.
Together with the motor and gear from Nidec, the eight functions in this PoC include an inverter from Renesas with 70- to approximately 100-kW output performance and a maximum efficiency said to be 99% or higher; a 1.5-kW output DC-DC converter, a 6.6kW charge OBC; a power distribution unit (PDU); a battery-management system (BMS); and a self-regulating positive temperature co-efficiency (PTC) heater control for cars.
The heating element inside a PTC heater has a positive temperature coefficient and its resistance increases with temperature. The heating elements maintain a constant temperature when supplied by a given voltage.
Control with a Single MCU and PMIC
While generally each function of an E-Axle requires a dedicated MCU and a power-management IC (PMIC) to control an X-in-1 system, Renesas claims it successfully implemented this new E-Axle system with only one MCU and a PMIC to control the entire 8-in-1 system. By systematically integrating these functions with a single MCU, the PoC has significantly reduced the number of components, as well as cost and size.
The PoC includes numerous Renesas products: the 32-bit MCU RH850/U2B for automotive control, a PMIC for the MCU, the RAJ2930004AGM isolated gate driver, an IGBT module for the inverter, and power devices for the DC-DC converter and OBC. The company also provides system support and software for customers, including reference designs and other software to accelerate EV development.
Nidec’s Climate-Change Efforts
Nidec Group specializes and handles motor application products based on "everything that spins and moves," centering around a motor business that comprises a product line ranging from small precision to supersized motors. Nidec will participate in the virtual exhibition of the Japan Pavilion at the 29th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP29), which will be held in Baku, Azerbaijan, from November 11-22, 2024.
COP29 is a United Nations conference to discuss climate-change issues around the world. The venue will have pavilions from countries and organizations, each presenting their sustainability initiatives. Nidec will showcase its initiatives toward achieving net-zero CO2 emissions, as well as products and technologies that contribute to decarbonization.
“In the rapidly changing EV market, there is a growing need for smaller and lower-cost E-Axle systems,” said Ryuji Omura, Senior Vice President, Deputy Chief Technology Officer and Head of the Nidec Semiconductor Solutions Center. “Having a single ECU manage an electric powertrain control unit will help lower the weight and cost of the system, reducing the number of components.
‘’This project made us realize the importance of developing a scalable design methodology, as the levels of X-in-1 system integration vary from segment to segment. By modifying the software configuration for multicore MCUs, we expect to build the foundation for an X-in-1 platform that can flexibly accommodate various combinations.”
Added Chris Allexandre, Senior Vice President and General Manager of Power at Renesas, “We are committed to delivering a broad range of power management products that work together with our digital products to provide complete, ready-to-use, system-level solutions. This approach enables Renesas to help customers accelerate their development and time to market.”