Introduction
The drivetrain of an electric vehicle is called an EV powertrain, and it is made up of important parts such as an electric motor, battery, and energy management system.
“This article provides a general schematic of an electric powertrain and outlines the various components that constitute the EV powertrain.”
The fundamental parts of a vehicle’s powertrain are in charge of producing and transferring power so that it can move forward. It transforms energy into motion by serving as the mechanical core.
EV powertrains use electric motors driven by rechargeable batteries instead of conventional powertrains, which use internal combustion engines that run on gasoline or diesel. As a result, there are no emissions from the tailpipe, and the engine runs smoothly.
EV Powertrain Components
- Battery Pack: The electric motor is powered by the battery pack, which is the main component of an electric vehicle. Moreover, the battery pack is composed of many lithium-ion cells.
- Electric Motor: Using a stator, rotor, and other essential components, an electric motor transforms electrical energy into mechanical energy to move the car forward. It improves acceleration and overall performance by providing immediate torque and great efficiency.
- Traction Inverter: An electric motor’s alternating current (AC) is produced by a traction inverter, which changes the direct current (DC) from the battery pack. It also modifies the frequency and amplitude of the AC to control the motor’s speed and torque.
- DC/DC Converter: The DC-DC converter transforms the battery pack’s high-voltage DC into the lower-voltage DC needed for the car’s accessories and other systems. Meanwhile, the onboard charger converts AC power from the electrical grid into DC power, ensuring that the battery pack is charged safely and efficiently. Together, these components play a crucial role in maintaining the functionality and performance of an electric vehicle.
- Battery Management System (BMS): Manages the charging and discharging cycles to optimize performance and safety while keeping an eye on the health of the battery pack.
- Gearbox: By doing away with the need for intricate multi-speed gearboxes, some EVs have direct drive systems or single-speed transmissions, which streamline the EV powertrain and increase economy.
- Actuator: Actuators regulate the operation of the electric motor and open and close valves, among other EV duties.
- Electric Controller Units (ECUs): ECUs control how much electricity goes from the battery to the motor, varying torque and speed to get the best results.
- Thermal Management System: This system, which often uses water or oil cooling, controls the temperature of EV powertrain components to preserve longevity and efficiency.
How Do EV Powertrains Operate?
The Power Generation System, the Power Distribution System, and the Mechanical System are the three main systems that make up the EV Powertrain system.
1. Power Generation System
The battery pack and the related management components are essential parts of the power-creating system. Specifically, electrical energy is stored in the battery pack, which is typically composed of lithium-ion cells. In addition, the Battery Management System (BMS) ensures safe and efficient operation by monitoring the battery’s health and performance while also regulating the charging and discharging processes. As a result, this system serves as the primary energy source for the electric motor and other essential components of the electric vehicle.
2. Power Distribution System
The power control module and the inverter, or DC-AC converter, together make up the power distribution system. To begin with, for the electric motor to run, the direct current (DC) from the battery must first be converted into alternating current (AC) via the inverter. Meanwhile, the power control module regulates the flow of electricity by modifying the frequency and amplitude of the AC to control the motor’s speed and torque. As a result, this ensures optimal vehicle performance and efficient power distribution.
3. Mechanical System
The drivetrain, gearbox, and electric motor are all part of the mechanical system. The vehicle is propelled by the electric motor, which transforms electrical energy into mechanical energy. The transmission system effectively distributes power from the motor to the wheels; it is often a single-speed gearbox. The car may then move because the drivetrain transfers this mechanical energy to the wheels. Regenerative braking is another feature of some sophisticated systems that allows energy to be recovered during braking and fed back into the battery.
Types of EV Powertrain
1. Battery Electric Vehicle (BEV) Powertrain
Description: Battery Electric Vehicles (BEVs) are fully electric vehicles that exclusively rely on a battery to power an electric motor. As a result, they do not require a gasoline engine or a fuel tank. Instead, they depend entirely on rechargeable batteries, which store and supply the necessary energy for propulsion. Consequently, BEVs produce zero tailpipe emissions, making them an environmentally friendly alternative to traditional internal combustion engine (ICE) vehicles.
Components:
- Battery Pack
- Electric Motor
- Inverter (DC-AC converter)
- Single-Speed Transmission
- Battery Management System (BMS)
- On-Board Charger
Operation: The battery stores electrical energy, which then powers the electric motor to drive the vehicle. Unlike traditional vehicles, a BEV has no internal combustion engine components, thereby resulting in zero tailpipe emissions.
Example: Tesla Model 3, Nissan Leaf.
2. Plug-in Hybrid Electric Vehicle (PHEV) Powertrain:
Description: PHEVs are similar to HEVs but have a larger battery that can be charged externally, enabling short-range all-electric travel.
Components:
- Engine with internal combustion (ICE)
- Electric Motor
- Larger Battery Pack (compared to HEVs)
- Inverter
- On-board charger
- Transmission
Operation: PHEVs may drive short distances entirely on electricity by using their batteries as power. The ICE starts working when the battery runs out. You can charge the battery using regenerative braking, the ICE, or via an external charger.
Example: Chevrolet Volt and Mitsubishi Outlander PHEV.
3. Fuel Cell Electric Vehicle (FCEV) Powertrain
Description: FCEVs generate electricity through the use of a hydrogen fuel cell, which subsequently powers an electric motor.
Components:
- Hydrogen Fuel Cell
- Electric Motor
- Small Battery Pack (for energy buffering)
- Hydrogen Tanks
Operation: The fuel cell’s oxygen and hydrogen storage tanks combine to produce energy.
Examples: Toyota Mirai, Hyundai Nexo.
4. Extended Range Electric Vehicle (EREV) Powertrain:
Description: EREVs are similar to BEVs, but they also contain a small gasoline engine that serves as a generator to replenish the battery when it runs low.
Components:
- Electric Motor
- Battery Pack
- Small Gasoline Engine (as a generator)
- Inverter
- Transmission
Operation:
Example: BMW i3 REx.
Fully EV powertrains, such as BEVs and FCEVs, offer the cleanest and most energy-efficient options. Each type of EV powertrain offers a different balance between electric and internal combustion energy.
Conclusion:
An important development in automobile technology is the EV Powertrain, which offers a more effective and sustainable substitute for conventional internal combustion engines. The electric powertrain, which consists of vital parts including the battery pack, electric motor, traction inverter, and energy management systems, transforms electrical energy stored in the vehicle into mechanical energy, allowing it to travel smoothly and emission-free.
Battery Electric Vehicles (BEVs), Plug-in Hybrid Electric Vehicles (PHEVs), Fuel Cell Electric Vehicles (FCEVs), and Extended Range Electric Vehicles (EREVs) are the four different types of EV powertrains, and each has specific benefits and capabilities.
The EV Powertrain is leading the way in providing cutting-edge solutions that strike a balance between environmental responsibility, performance, and efficiency as the demand for sustainable mobility keeps rising. The advancement of this technology not only makes driving more enjoyable but also helps the automobile sector have a more sustainable future.
Dorleco provides advanced VCUs, CAN Keypads, CAN Displays, and EV software services for optimized control, communication, and powertrain integration. Learn more about EV components—contact us at info@dorleco.com.