In this post, we’re discussing facts about a hybrid car. The term “hybrid” comes from the fact that these vehicles utilize both an internal combustion engine and an electric motor for propulsion.
Every fully hybrid vehicle consists of six essential components:
- an internal combustion engine
- an electric motor
- a generator
- a transmission
- a power control module
- a 12-volt auxiliary battery and
- a high voltage battery.
Let’s first examine the key components of a fully hybrid vehicle.
Internal Combustion Engine
This engine is comparable to the traditional gasoline or diesel engines found in most vehicles. It generates power by burning fuel and is typically smaller and more efficient, focusing on supporting the electric motor and enhancing fuel economy.
It activates during high-demand situations, such as acceleration or highway driving.
Electric Motor
The electric motor is the core of the electric drivetrain, converting electrical energy into power to drive the wheels.
It is typically a permanent magnet synchronous motor, selected for its efficiency and durability. This motor provides instant torque, ensuring smooth acceleration, and supplements the engine to improve fuel economy.
Generator
In many hybrid car designs, the electric motor also functions as a generator. Its primary role is to charge the high voltage battery.
The electric motor, when acting as a generator, produces three-phase alternating current, usually ranging from 100 to 600 volts, depending on the system and battery voltage.
Transmission
The transmission in a hybrid car is crucial for managing the combined power from the engine and electric motors and delivering it to the final drive.
Power Control Module (PCM)
The PCM serves as the central control unit for the hybrid system, overseeing the power flow between components.
It converts AC electricity from the generator to DC for the batteries and inverts DC electricity from the high voltage battery to high-voltage AC for the electric motor.
Beyond voltage transmission, the PCM oversees power flow and controls both the motor and engine to ensure optimal performance and efficiency.
12-Volt Auxiliary Battery
This battery functions similarly to a standard lead-acid battery found in conventional cars, powering electrical accessories like lights, radio, infotainment systems, and electronic control modules.
Some vehicles have two auxiliary batteries—one for auxiliary systems and another for engine starting.
High Voltage Battery
The high voltage battery stores electrical energy to power the high voltage electric motor. It typically consists of a lithium-ion or nickel-metal hydride battery pack, chosen for its high capacity and energy density.
Most hybrid cars have high voltage batteries ranging from 100 to 400 volts, balancing efficiency, power delivery, and safety.
[Electric or Hybrid Cars – Which one to choose?]
Types of Hybrid Vehicles
Fully hybrid vehicles are classified into three primary types:
- series hybrids
- parallel hybrids, and
- series-parallel hybrids.
These categories are based on how power flows from the initial source to the final drive.
Series Hybrid Vehicles
In a series hybrid car configuration, the internal combustion engine drives the generator, also known as the motor generator unit.
This generator produces three-phase high AC voltage, which can reach up to 600 volts in some vehicles. The AC voltage is routed to the power control module, which converts it into high DC voltage for the high voltage battery and standard DC for the auxiliary battery.
The high voltage battery stores electrical energy and releases it to the PCM when needed. The PCM then converts this DC voltage back into AC to power the three-phase AC electric motor.
The motor drives the transmission, which transfers power to the final drive, moving the vehicle forward. The engine primarily operates to charge the high voltage battery and provide additional power or speed when required.
Parallel Hybrid Vehicles
In parallel hybrids, both the engine and the electric motor work independently to propel the vehicle. The system can operate in different modes:
- Combustion Mode: The engine provides primary propulsion.
- Electric Mode: The vehicle operates exclusively on electric power from the motor.
- Combined Mode: Both the engine and electric motor work together to power the wheels.
In a parallel hybrid, the engine is generally the primary propulsion source, with the electric motor serving as a backup or torque booster.
The engine can drive the generator through a transmission unit, converting mechanical energy into electrical energy to charge the battery pack.
Series-Parallel Hybrid Vehicles
Series-parallel hybrids combine features of both series and parallel configurations. The engine can transfer power directly to the transmission through a power split unit, which enables multiple power paths: a mechanical path linking the engine to the transmission and an electrical path transferring power from the electric motor to the transmission.
The power split device adjusts the power distribution based on driving conditions and driver demands, offering versatility and efficiency. The system operates in series mode, parallel mode, and combined mode:
- Electric Mode: The vehicle operates exclusively using power from the electric motor.
- Combustion Mode: The engine provides primary propulsion.
- Combined Mode: Both the engine and motor work together to power the wheels.
Conclusion
In summary, a fully hybrid car fall into three main categories: series, parallel, and series-parallel hybrids.
In series hybrids, power is transferred from the engine to the motor and then to the transmission. In parallel hybrids, power is transmitted from both the engine and motor to the transmission. Series-parallel hybrids use a power split unit to transfer power to the transmission.
While series hybrids have a single power pathway and parallel hybrids have three, series-parallel hybrids offer all modes and allow shifting between them. Generally, series-parallel hybrids are the most efficient hybrid type.
Next, I’ll explain the differences between a fully electric vehicle and a hybrid car.
That’s all for today. If you find this content valuable, consider subscribing to my Youtube channel Noah’s Garage.
References:
Wikepedia
https://en.wikipedia.org/wiki/Plug-in_hybrid
Image Credits:
AFDC.Energy.Gov
https://afdc.energy.gov/vehicles/how-do-hybrid-electric-cars-work
