Introduction

In a world battling the climate change crisis at an unprecedented level, electric vehicles (EVs) have emerged as a great alternative to make transportation as clean and green as possible. Often tagged as the “car of the future”, electric cars imbibe cutting-edge technology, transforming driving experiences. In this article, we will understand the fundamental architecture and components of electric vehicles to understand how they work and what makes them promising for the future.

The basics of electric vehicle architecture

As the name suggests, an electric vehicle is powered by electricity instead of fuel. The architecture of an EV comprises the following components:

1.Traction battery pack

Considered the heart of an EV, the battery is a rechargeable energy storage system that provides power to the electric motor. The energy is stored in cells connected in series or parallel to form different battery modules, and multiple modules are then linked in series to create the battery pack, commonly known as High Voltage battery or HV battery in vehicle.

EV batteries comprises of lithium-ion cells in various shapes tailored for specific applications. They include Prismatic cells, Cylindrical and Pouch cells. An EV’s range, performance, and weight depend on the size, capacity, and chemistry of the battery pack to a large extent.

EVs can use different types of batteries like lead acid, lithium-ion, nickel metal hydride, and nickel cadmium. Lithium-ion batteries are the most popularly used batteries in all electric and plug-in hybrid electric vehicles (PHEVs).

2. Electric motor

Electric vehicles comprise an electric motor, usually an alternating current (AC) induction motor or a permanent magnet motor, to convert electrical energy into mechanical power. The motor moves the vehicle and sets its wheels in motion. EV motors deliver instant torque for a seamless and responsive driving experience.

3. Power Electronics and Control (PCU) systems:

The power electronics and control systems manage the flow of electricity between the battery, motor, and other vehicle components. The PCU manages and controls braking, acceleration, and regenerative braking. Electric cars that have advanced power control systems have an optimal energy usage and have enhanced safety and operational features.  

1. Charging port: A charging port allows electric cars to connect to external power sources for recharging the battery. Primarily, there are six types of connectors used in EVs worldwide - Type 1, Type 2, CHAdeMo, CCS, GB/T, and IEC 60309.
2. Onboard charger: Though the battery present in the vehicle gets charged by using DC or direct current, the current output from the charging station or a charger is in form of AC or alternating current. The function of onboard charger is to convert alternating current (AC) from the charging source into direct current (DC) to charge the battery.  The charging speed and compatibility is independent of onboard charger and depends on the source charger's capacity and BMS.
3. High-Voltage DC-DC converter: This module converts high-voltage DC power from the battery into lower-voltage DC power, which is necessary for various vehicle systems, including lighting, entertainment, and air conditioning.

4. Regenerative Braking System

A unique technique used in hybrid and fully electric cars, regenerative braking allows the electric motor to capture kinetic energy and convert it back into electrical energy, which is then used to recharge the high-voltage battery.

5. Vehicle Control Unit

The vehicle controller or electronic control unit (ECU) is an integrated circuit/chip which is regarded as the brain of the vehicle. In addition to essential functions like engine performance and power steering, it controls safety and comfort features, such as parking assistance, memory seats and airbag deployment. The vehicle control unit is responsible for all internal communications between various systems deployed in the vehicle and enabling them whenever required.

1. Battery Management System (BMS): The BMS monitors the state of charge (SoC), state of health (SoH), and overall health of the battery pack. The BMS ensures that the battery performs within safe limits. To protect the battery from thermal runaway and overcharging, BMS stops the input current to the battery and disconnects it from charger or load. The BMS is also responsible for managing key battery aspects like thermal management, cell balancing, and communication and reporting.
2. User interface and display: Electric cars have user interfaces and displays that provide information to the driver and passengers, including battery status, range estimation, and charging information.
3. Safety systems: Like traditional ICE vehicles, EVs incorporate safety features like airbags, anti-lock brakes, stability control, and collision avoidance systems.

For instance, the MG ZS EV hosts a range of safety features that improve safety and comfort for the drivers. These include:

Conclusion

As the electric car market witnesses the introduction of a wide range of sleek and sophisticated models, a fundamental understanding of their architecture will help you assess your options better and make the right choice.