Context: India has launched the country’s first 9000 HorsePower (HP) electric freight locomotive engine at Dahod, Gujarat with regenerative braking capability.
Relevance of the Topic: Prelims: Key facts about Regenerative Braking System.
Dahod-9000 Electric Engine:
- Manufactured in: Dahod, Gujarat in collaboration with German engineering firm Siemens.
- 9000 horsepower (HP) locomotive engine. Haulage capacity- 5800 tonnes.
- Has regenerative braking capability, i.e., when the engine brakes, it becomes a generator and produces power.
- Six-axle electric engine with an average speed of 75 km/h (max speed of 120 km/h). No noise or vibration (in this engine).
- Advantages: High quality; low cost; high export potential; boost freight movement; reduce CO2 emissions.
What is a Regenerative Braking System?
- A regenerative braking system is a technology used in electric and hybrid vehicles to recover the kinetic energy of the vehicle that would otherwise be lost during braking.
- Braking is the mechanism by which an automotive vehicle in motion slows down.
- A vehicle moving faster has more kinetic energy than a vehicle moving slower, so the process of braking removes (mostly) kinetic energy from the vehicle.
- In the traditional braking systems, when the brakes are applied the kinetic energy from the vehicle is converted into heat, which is then dissipated into the environment.
- In regenerative braking systems, instead of converting the kinetic energy into heat, it is converted into electrical energy which can then be stored in the vehicle's battery for later use. This is done by using the electric motor in the vehicle which acts as a generator during the braking process.
How does a Regenerative Braking System work?
- Kinetic Energy Conversion: When a vehicle is in motion, it possesses kinetic energy. When the driver applies the brakes, the regenerative braking system starts working.
- Motor as a Generator: The electric motor which normally drives the wheels, operates in reverse during braking. It starts acting as a generator, converting the vehicle's kinetic energy into electrical energy.
- Energy Storage: The electrical energy generated during braking is directed to the vehicle's battery or a supercapacitor for storage.
- Energy Reuse: The stored energy can be used later to power the vehicle, reducing the need to draw as much power from external sources and improving the vehicle's overall efficiency.
Benefits of Regenerative Braking:
- Improved Energy Efficiency & reduced emissions: By recovering and reusing energy, regenerative braking reduces the overall energy consumption of the vehicle and reduces emission of heat.
- Reduced Wear and Tear: Because regenerative braking reduces reliance on traditional friction brakes, it can decrease wear and tear on brake components, leading to lower maintenance costs.
Limitations:
- Efficiency Variations: The efficiency of energy recovery decreases as the vehicle's speed drops. (Lesser the speed of vehicle, lesser kinetic energy is available for conversion to electrical energy and storage)
- Not a Complete Replacement: Regenerative braking often cannot bring a vehicle to a complete stop on its own and must be supplemented with conventional braking systems.