Electric vehicles (EVs) are becoming more popular and affordable as technology advances and environmental awareness grows. EVs offer many benefits, such as lower emissions, reduced fuel costs, and less noise pollution. However, EVs also face challenges, such as limited range, high battery weight, and different driving dynamics. One of the most important aspects of EV performance and comfort is the suspension system, which connects the wheels to the body and absorbs the shocks and vibrations from the road. We will explain how EV suspension technology works, its advantages and disadvantages, and the latest developments and trends in this field.
What is EV suspension technology?
EV suspension technology is the design and implementation of suspension systems that are optimized for electric vehicles. Suspension systems are composed of three main components: springs, dampers, and linkages. Springs store and release energy when the wheels move up and down, dampers dissipate energy to control the oscillations of the springs, and linkages connect the wheels to the body and allow for steering and alignment adjustments.
EV suspension technology differs from conventional suspension technology in several ways. First, EVs have different weight distribution and center of gravity than internal combustion engine (ICE) vehicles due to the placement and size of the battery pack. This affects the handling, stability, and ride quality of the vehicle. Second, EVs have different powertrain characteristics than ICE vehicles, such as instant torque delivery, regenerative braking, and lower noise levels. This affects the acceleration, deceleration, and vibration of the vehicle. Third, EVs have different packaging constraints than ICE vehicles due to the absence of engine components and the presence of electric motors and electronic modules. This affects the space available for suspension components and their configuration.
Therefore, EV suspension technology aims to address these challenges and provide optimal performance and comfort for electric vehicles. There are three main types of EV suspension technology: passive suspension, semi-active suspension, and active suspension.
Passive suspension is the simplest and most common type of suspension system. It uses fixed springs and dampers that do not change their characteristics according to the road or driving conditions. Passive suspension is relatively cheap, reliable, and easy to maintain. However, the passive suspension has some drawbacks for EVs. It cannot adapt to different load conditions caused by varying battery weight or passenger/cargo weight. It cannot compensate for different road surfaces or driving styles requiring different stiffness or damping levels. It cannot recover energy from the suspension movement that is otherwise wasted as heat.
Semi-active suspension is a type of suspension system that uses variable dampers that can change their damping coefficient according to the road or driving conditions. The semi-active suspension uses sensors to monitor the vehicle's movement and ride height and actuators to adjust the damping force of the dampers. Semi-active suspension can improve the performance and comfort of EVs by providing better control over body roll, pitch, bounce, and squat. It can also reduce energy consumption by minimizing unnecessary damping force when the road is smooth, or the vehicle is cruising. However, the semi-active suspension still relies on passive springs that cannot change their stiffness or recover energy.
Active suspension is a type of suspension system that uses active actuators that can generate active control force to counteract road or driving disturbances. The active suspension uses sensors to monitor the vehicle's movement and ride height, actuators to apply force to the wheels or body independently at each corner, and a controller to coordinate the actuator actions based on a desired target state. Active suspension can offer superior performance and comfort for EVs by providing full control over body roll, pitch, bounce, squat, heave, warp, and shake. It can also reduce energy consumption by recovering energy from the suspension movement that can be stored in the battery or used for other purposes.