The anxiety over the overwhelming rate of utilization of fossil fuels forced studies to look out for alternate sources of energy. The motive of the efforts is to save the fossil fuels for the future generation along with meeting the present needs. This led to the concept of sustainability development.
Automobiles constitute a major portion of the fossil fuel consumption share. Consequently cars driven by batteries and solar energy came into market. But their capabilities were limited because of the limitations of the solar technology and the batteries as they are still in premature stage of their development. In this scenario, hybrid cars came into picture. This technology offers cars to choose the mode of operation. They can either work like conventional fossil fuel cars or by energy from solar panels and batteries.
About the technology
A hybrid vehicle has the dual advantages of an IC engine and electric motors to run the vehicle. The IC engine in a hybrid vehicle is smaller than a conventional IC engine car and is more efficient. The electric motors can either be AC or DC. The electrical system has then to be chosen to suit the power requirement of the motors. Each of the system has merits and demerits. The hybrid vehicles are additionally supplemented by regenerative braking that charges the battery every time the brakes are applied; or they can be supplemented with grid charged or solar charged batteries or both.
In a motor vehicle, powertrain is a term that is used to refer to the components or parts that generate power to move the vehicle. A hybrid vehicle can use various types of power trains.
1. Series hybrids: In this fossil fuel driven IC engine vehicle, the engine generates the electrical power, which is used to run the motors. These type of vehicles are dominated by the merits of the electrical system that is used over the demerits of the mechanical systems.
2. Parallel hybrids : In these types of hybrids, the power to drive the vehicle comes from both the IC engine and the batteries. The source power cane be change to any one of them or both can be used to drive the vehicle.
3. Series-parallel hybrids: These hybrids have the flexibility to choose the mode of powertrain to go either series or parallel. Most of the plug-in hybrids use the series-parallel powertrain.
The major developments in the power electronics domain has been a vantage point for the hybrid vehicles.
The power converters have improved over the years and they produce better quality power to run the vehicles.
These are helpful when power conversions between AC and DC has to take place to suit the requirements of the electrical motors. Development in high frequency IGBT and MOSFET systems have led to better utilization of the motors.
The hybrid vehicles come with lots of merits. The emission of green house gases are reduced and it leads to lesser pollution and less global warming. They produce considerably less noise than the IC engines. The dependance over the fossil fuels have reduced and it is economic in the sense that the prices of them are soaring high day by day. Whereas the non-renewable technology practically comes free of cost. Investment needs to be made in the technology that is used to harness them. Although the initial investment is very high but they fetch the worth if it over long run. In certain countries like U.S.A and U.K, the government gives subsidies and certain incentives to the customers who purchase hybrid or green vehicles.
The battery sizes and the related weight issues are limiting factors in the development. Though the lithium ion and Ni-Cd batteries come in smaller sizes, their running time is limited and they can last up to 100 km. The charging of the batteries while on the drive is not feasible and hence it is not advisable to make a trip to the places for long time in places where charging sockets are not present. They are also characterized by initial high investment costs. They are complex system with complex designs. In case of any faults, expert service is required and a local garage can be of little or no help.
Future scope and analysis
Manufacturers have come up with new materials like carbon resins and polymer fibers that are light have energy storing capabilities. Reduction in weight of the batteries with longer endurance capabilities will suit the vehicles. Commutation problem in DC motors has come down with better quality power electronic converters. The future of the hybrid vehicles can be more beneficial for environment and mankind.