The internal combustion engine (ICE) has been refined and developed over the last 100 years for a wide variety of applications from tiny 1 cc engines powering model aircraft to gigantic marine engines with power outputs of tens of MegaWatts. The reciprocating engine with its compact size and its wide range of power outputs and fuel options is an ideal prime mover for powering electricity generating sets (gensets) used to provide primary power in remote locations or more generally for providing mobile and emergency or stand-by electrical power.
Generating sets are designed to work at fixed speeds because of the requirement to provide a fixed frequency AC voltage output. A rotor speed monitor provides an indication of the generator output frequency and this is fed back to control the fuel supply valve to keep the frequency constant.
- Primary Power
- Large Diesel generators are used for primary power applications
- Emergency Power
- Small portable generators often used for emergency power may be petrol (gasoline) or diesel powered. Remote, unmanned applications are usually provide with an auto start-stop capability.
- Electric Traction
- The first Diesel electric hybrid vehicle was patented in 1914 by Hermann Lemp. It used electric traction for the transmission system to avoid the use of complex gearing mechanisms necessary to deliver the power of the Diesel ICE to the wheels over the full range of train speeds since electric motors can operate over a wider speed range and can be more easily controlled. It used DC motors for this purpose and the DC power was provided by a DC generator driven by the Diesel engine. Modern Diesel electrics use AC machines to avoid the use of unreliable commutators and brushes in the motors and generators. Using Diesel electric power permits flexible routing and avoids the cost of the expensive infrastructure of overhead wires needed by pure electric trains. Electrical output power may be as low as 200 kW for a small passenger vehicle and up to 2 MW for a large freight train.