Motoring corner : “The Hybrid Vehicle”

As the pump prices have lately been moving up and up, this has become nearly every motorist’s nightmare.  Maybe you have been thinking hard on the best or most economical way to curtail this trend, maybe not!  In our last edition, we looked at an electric car, could this be the one to save the situation or not? 

Saturday, January 29, 2011

As the pump prices have lately been moving up and up, this has become nearly every motorist’s nightmare.  Maybe you have been thinking hard on the best or most economical way to curtail this trend, maybe not!  In our last edition, we looked at an electric car, could this be the one to save the situation or not? 

On the other hand, is your car is contributing to the greenhouse effect?  You are not alone; the auto industry has the technology to address these concerns. It is in the hybrid car.

There are a lot of hybrid models on the market these days, and most automobile manufacturers have announced plans to manufacture their own versions.

That said and done, how does a hybrid vehicle work or what is it all about?  What goes on under the hood to give you 10 or 15 or so extra kilometres per litre than the standard vehicle? And does it pollute less just because it gets better fuel per mileage?  ­­Many people have probably owned a hybrid vehicle at some point e.g. a motorized pedal bike, a type of hybrid because it combines the power of a petrol engine with the pedal power of its rider.

In fact, hybrid vehicles are all around us. Diesel-electric buses that can draw electric power from overhead wires or run on diesel when they are away from the wires or giant dump trucks that are often diesel-electric hybrids e.t.c. Any vehicle that combines two or more sources of power that can directly or indirectly provide propulsion power is a hybrid. Most hybrid cars on the road right now are petrol-electric hybrids, although Peugeot and Citroen have two diesel-electric hybrid cars to their credit.

The petrol-electric hybrid car is just like it sounds a cross between a petrol-powered car and an electric car.  A petrol-powered car has a fuel tank, which supplies petrol to the engine. The engine then turns a transmission, which turns the wheels.  An electric car, on the other hand, has a set of batteries that provides electricity to an electric motor. The motor turns a transmission, and the transmission turns the wheels.  

The hybrid is a compromise. It attempts to significantly increase the mileage and reduce the emissions of a petrol-powered car while overcoming the shortcomings of an electric car.  To be useful to you or me, a car must meet certain minimum requirements. The car should be able to be driven at least 480 km before re-fuelling, be refuelled quickly and easily and it should keep up with the other traffic on the road.

Though a petrol car meets these requirements, it produces a relatively large amount of pollution and generally gets poor petrol mileage. An electric car, however, produces almost no pollution, but it can only go 80 to 160 km between charges and the problem has been that the electric car is very slow and inconvenient to recharge.  A petrol-electric car combines these two setups into one system that leverages both petrol power and electric power.

The Petrol-electric hybrid cars contain the following main components; - The hybrid car has a petrol engine much like the one you will find on most cars. However, the engine on a hybrid is smaller and uses advanced technologies to reduce emissions and increase efficiency.  Fuel tank - The fuel tank in a hybrid is the energy storage device for the petrol engine. Petrol has a much higher energy density than batteries do. For example, it takes close to 500 kilograms of batteries to store as much energy as 10 litres of petrol.

Electric motor - The electric motor on a hybrid car is very sophisticated. Advanced electronics allow it to act as a motor as well as a generator. For example, when it needs to, it can draw energy from the batteries to accelerate the car. But acting as a generator, it can slow the car down and return energy to the batteries.  Generator - The generator is similar to an electric motor, but it acts only to produce electrical power. It is used mostly on series hybrids.  Batteries - The batteries in a hybrid car are the energy storage device for the electric motor. Unlike the petrol in the fuel tank, which can only power the petrol engine, the electric motor on a hybrid car can put energy into the batteries as well as draw energy from them.

Transmission - The transmission on a hybrid car performs the same basic function as the transmission on a conventional car. Some hybrids, like the Honda Insight, have conventional transmissions. Others, like the Toyota Prius, have radically different ones.

You can combine the two power sources found in a hybrid car in different ways. One way, known as a parallel hybrid, has a fuel tank that supplies petrol to the engine and a set of batteries that supplies power to the electric motor. Both the engine and the electric motor can turn the transmission at the same time, and the transmission then turns the wheels. 

 The animation below shows a typical parallel hybrid. You’ll notice that the fuel tank and gas engine connect to the transmission. The batteries and electric motor also connect to the transmission independently. As a result, in a parallel hybrid, both the electric motor and the gas engine can provide propulsion power. (to be cont’d)

 motoringcorner@live.co.uk