EVs are powered by electric motors that turn stored energy into motion. They emit no tailpipe pollutants and can use renewable electricity or fuel cell technology.
Learn how EVs work and why they are such an important solution to climate change. This guide will examine how the powertrain functions and its component parts to help you understand why EVs are growing in popularity.
Motors
The heart of an electric vehicle is the motor that delivers power to the wheels. It draws its electricity from the batteries, which provide direct current. A controller transforms that DC into the alternating current required for AC motors, and it controls how much power is delivered based on pressing the accelerator pedal.
Most EVs use single-speed transmissions to reduce friction and maximize acceleration ability. Some use multi-gear units to improve efficiency at highway speeds.
The biggest advantage of EVs is that they have zero tailpipe emissions. However, their batteries rely on rare minerals that must be mined and refined, and they require regular maintenance. They also can be slow to charge and are sometimes difficult to find a charging station nearby. In addition, EVs can cause traffic congestion and take up parking spaces that could be used by people on foot or riding bicycles.
Batteries
Batteries supply the electric vehicle with the energy it needs to move and recharge. They are also the main component that defines the range of an electric car.
Selection of battery type is largely based on energy density. The ideal battery will give the most energy for the smallest volume and weight. There are a number of different battery technologies in use today: lead-acid (Pb-acid), nickel cadmium, nickel metal hydride and lithium-ion batteries.
EV manufacturers are continually improving battery technology in terms of energy density and production costs while also working to address key safety issues. Solid state batteries with cells that have a solid electrolyte are one such advancement.
Battery packs are monitored by a suite of sensors during charging and discharging which is part of a complex system known as the Battery Management System (BMS). This ensures that all cells within the pack are performing correctly. Improvements such as cell to body (CTB) that integrates the battery pack directly into the floor panel of an EV can reduce cost and space requirements.
Inverters
Inverters are key components that manage electric vehicle power. They convert DC from batteries into AC for motors to use and also control the power output to meet various vehicle requirements, such as torque.
The inverter can also be used to change the speed of an EV’s engine to match the vehicle’s driving style. This allows the EV to drive as smoothly and efficiently as a traditional car.
Typical inverters take the battery DC voltage and convert it to 3 phase alternating current for motors such as permanent magnet or high-speed field reluctance motors. They typically use IGBTs or Mosfet transistors.
Several key factors have driven market expansion of the EV inverter sector. These include rising environmental concerns and supportive government policies in Asia-Pacific. Current inverters must comply with a number of national standards and technical specifications to ensure they are safe to use. They are also subject to stringent testing and quality assurance processes to guarantee that they are reliable and durable.
Charging
Electric vehicles operate like traditional gasoline cars, except that instead of carrying energy in a tank, they carry electrical power in batteries. The batteries supply the electricity to the motor, which in turn drives the wheels. The vehicle accessories (radio, lights, heating and air conditioning) also draw their power from the battery.
The EV battery can be recharged from the utility power grid or from onboard charging equipment. The recharging process is fast and efficient, and the amount of time to recharge an EV battery has decreased significantly over the past few years due to innovations in charger technology.
There are a variety of EV battery chemistries, most of which require critical minerals such as lithium, cobalt and nickel. However, there are newer EV battery chemistry technologies such as LiFePO4 that do not rely on these key metals.