A car brake is designed originally to serve one purpose, which is to stop cars. It consists of multiple parts, making its working complex even though the actuation is just by pressing a foot pedal. The system holds a greater potential in energy efficiency, which has brought about a regenerative braking system.
In this reading, we’ll learn what a regenerative braking system is, its diagram, parts, types, and how it works. We’ll also learn its advantages and disadvantages.
Let’s get started!
What Is A Regenerative Braking System?
The regenerative braking system is known as electromagnetic braking and is used on hybrid and electric cars. Just as earlier mentioned, it recaptures lost energy. Well, working is quite simple and easy to understand. The energy lost in the braking is recollected and converted into electric energy for the large, high-capacity battery.
The difference between traditional and regenerative (electromagnetic) braking is the creation of energy. Vehicles designed with regenerative brakes are actuated by driving the motor in reverse. This is achieved as the brake pedal is pressed, and the vehicle’s electric motor is automatically placed into reverse mode.
It causes the vehicle to run backward. With this principle, the car wheels do not only slow the wheel but also generate electricity for the car. The reverse motion that occurs as the brake is pressed is what causes this. Vehicles that use regenerative braking also have friction brakes to support the regenerative braking when it loses power or is not supplying enough power to stop the vehicle.
The electronic circuitry and onboard computer of the car determine when the conventional frictional braking system will be used. At the same time is to handle the engagement of the reverse motion. The force the driver applies to the pedal will determine a slight reduction in the car’s momentum. This will cause the vehicle’s electronics to engage the regenerative brakes and make the motor reverse.
Diagram Of Regenerative Braking System
Related: What Is A Hydraulic Braking System? Its Diagram and How It Work
Parts Of A Regenerative Braking
Being an electric brake system, regenerative braking primarily consists of electrical and electronic components. Here are the components that make up the Regenerative Braking System:
- Battery Pack: This part powers the electric traction motor and ECU.
- Electronic Control Unit (ECU): The ECU manages the system’s operations, including controlling the motor and hydraulic functions.
- Electric Traction Motor: It drives the vehicle and, in some designs, may also power the hydraulic pump.
- Hydraulic Pump: Its job is to converts electric power from the motor into hydraulic pressure.
- Accumulator: This one stores hydraulic energy for use when needed.
- Hydraulic Circuit: The circuit distributes hydraulic fluid through the system.
- Hydraulic Valves: This helps control the flow and direction of hydraulic fluid within the circuit.
- Reservoir: And the reservoir stores excess hydraulic fluid for the system.
Types Of Regenerative Braking System
The following are the common types of regenerative braking systems in a car:
Hydraulic
The hydraulic RBS reduces the speed of the car by compressing a fluid using electricity. It is common practice to use nitrogen gas as the working fluid. A hydraulic RBS can store more energy for a longer period of time than any other system since compressed fluid does not lose its energy with time. However, using a pump to compress gas is a slow procedure that significantly reduces the hydraulic RBS’s power.
Electromagnetic
Vehicles using electromagnetic systems have their drive shafts attached to electric generators, which slow down the vehicle and produce electricity by limiting the drive shaft’s rotation with magnetic fields.
Electric vehicles and hybrid cars use the electricity they create to recharge their batteries. Electricity in gas-powered cars can either be used to power the electronics or stored in a battery to provide the vehicle with more power later on. These days, some Le Mans prototype race cars use this approach.
Flywheel
The flywheel RBS system uses the vehicle’s kinetic energy to turn a flywheel by connecting it to the drive shaft via a gearbox and transmission. The car can gain more power by using the torque that the spinning flywheel can supply to the driving shaft.
Electromagnetic-Flywheel
A combination of electromagnetic and flywheel regenerative brakes is the electro flywheel regenerative brake. It uses the same fundamental techniques for generating power as the electromagnetic system, but instead of storing the energy in batteries, it uses a flywheel.
The flywheel functions as a mechanical battery in this way, storing and retrieving electrical energy. Electric flywheel RBS is the more economical way to store electricity because flywheel batteries last longer than lithium-ion batteries.
Spring
Typically, human-powered vehicles like wheelchairs and bicycles use spring-loaded regenerative braking systems. Spring RBS stores energy as elastic potential by winding a coil or spring around a cone during braking. The driver can then use the potential to help them navigate tough terrain or uphill.
Related: What Is An Anti-Lock Braking System? Its Parts And How It Work
How Regenerative Braking Works
Regenerative Braking Mechanism (also known as Energy Recovery Mechanism) slows down the car engine at an incline by applying force to the brake pedal, which causes the motor to travel in the opposite direction.
The engine works as a generator, converting torque energy into electrical energy while acting in the opposite way. There is a decrease in emissions and fuel consumption in this manner as well. There are two circuits in the hydraulic circuit of the regenerative braking system: the driving circuit and the drain circuit.
The driving circuit includes a two-position four-way valve in addition to a cartridge valve, which is a one-way valve. The secondary component uses a pump or motor to direct the flow of oil from the reservoir to the accumulator when the brakes are applied, shifting the valve to the left.
In pump mode, the secondary component uses the vehicle’s kinetic energy to pressurize the oil in the reservoir so that it flows into the accumulator. In order to regulate all of the vehicle’s motors, the brake control sensor monitors wheel speed and torque to determine the amount of power that will be generated and the amount of rotating force that will be sent to the battery.
While braking, the brake control sensor distributes the electrical energy the motor produces to the battery. These ultracapacitors and ultra-high-speed flywheels are also utilized for energy storage.
Advantages
It goes without saying that capturing and utilizing more energy when you brake can increase your vehicle’s efficiency. It also means your brakes will not wear out as quickly. Regenerative braking has the following major benefits:
Extended Lifespan for Brake Pads and Rotors
EVs and hybrids are equipped with conventional hydraulic brakes, despite the fact that regenerative braking generates a significant amount of stopping force. Nevertheless, the brake pads and rotors are used far less frequently because regenerative braking does almost all of the work when slowing the car.
Consequently, drivers can save money on maintenance because they usually last considerably longer between servicing. However, you should still get your brakes checked often; in fact, your manufacturer’s recommended maintenance schedule can include inspections of your brakes. Tires Plus offers accessible and speedy inspections for hybrid and electric vehicles.
Improved Hybrid Fuel Economy
Hybrids are made to make the most of their electric powertrain, even if they still have internal combustion engines. With regenerative braking, drivers can keep their battery packs charged and cut down on engine use, which in turn reduces fuel consumption and costs.
Extending EV Range Efficiently
One way to increase the range of your electric vehicle is to collect the energy you use when braking and transfer it directly to the battery pack. Regenerative braking has the ability to increase an electric vehicle’s operating range by hundreds of miles over the course of the year, according to estimates. As a result, you will spend less time charging and more time actually traveling. Every mile matters since charging stations are still scarce in many places.
Disadvantages
Even while regenerative braking has more advantages than disadvantages, no technology is flawless. The following are some situations in which regenerative braking is lacking:
At Lower Speeds, It Can Be Less Effective
Your car has less kinetic energy and needs less braking effort when you drive more slowly. As a result, the battery pack receives less charge and less energy from the regenerative braking system. Additionally, many car manufacturers believe that in some circumstances, coasting can be more advantageous than regenerative braking.
Reduced Stopping Power
Regenerative braking might not offer as much stopping force as traditional brakes, even though it works perfectly in most braking scenarios where you come to a stop gradually. Because of this, drivers of hybrid and electric vehicles may need to apply more force to the brakes for the same stopping power. Modern regenerative braking systems, however, are making progress in this area as well. You might not even notice a change in stopping power in modern car models.
Different Brake Pedal Sensations
When driving, you want to make sure that your brake pedal is functioning. Although the brake pedals in electric and hybrid cars do work, you might not be accustomed to how they feel. A pedal that does not crush as smoothly as you would like or sudden unresponsiveness are possible.
You might need to modulate the pedal differently in various situations. The good news is that this shift in the feel of the brake pedal is not as problematic as it formerly was. The brake pedals on newer EV and hybrid vehicles are more responsive and feel the same as those on any other type of brake.