Generating units match

In order to ensure the unit to achieve the technical indicators, unit design and manufacture, diesel engines and generators must be a good match, which includes both power and speed. Diesel power is the rated speed diesel engine to run 12 consecutive hours beyond the normal reach of effective power. The power of synchronous generator is at rated speed, long-term continuous operation, the output terminal to get the rated power. Usually rated engine power (hp) synchronous generator rated power (kW) is called the matching ratio. In the plains the general requirements on the use of the unit matches the ratio of 1.6:1; for some of the demanding mobile power station, take the 2:1 matching ratio. Speed ​​matching requirements are very strict. Speed ​​and unit power, frequency, voltage and others have a close relationship, thus supporting the diesel generator requirements and must have good performance and reliable governor who work to ensure that the generators brought in a relatively short period of time It’s rated speed and stable operation, but also to meet the load changes on the governor’s request.
The unit can run diesel generators to run a single unit can also be incorporated into multiple parallel operation and power system operation. A single unit operation by many conditions: if the power required to meet the heavy conditions, light load operation will reduce the unit to run the economy, and its spare capacity of the unit but also with the same run unit. The use of multiple units operating in parallel and grid operation, can be expanded supply capacity and improve reliability of supply, the standby unit can have a relatively reduced reserve capacity of the unit.
To achieve parallel operation must meet the following four conditions: ① terminal voltage equal; ② same frequency; ③ phase-coherent; ④ the same phase sequence. But also have run protection devices, can automatically adjust the rational allocation and active and reactive power, the unit features and regulator between the FM curve tends to close.
Features diesel engine supplier and turbine-generator group, has the following characteristics: ① output per unit of small size, light weight, simple system, and more generally for the whole package. Therefore, the diesel power plant construction speed. ② high thermal efficiency of diesel power generation, and part-load or light load, the fuel consumption per unit of output changes little. ③ diesel generator starting, stopping with a load and a shorter time, it can start at any time, more suitable for emergency power. ④ than the diesel generator turbine generator operation and maintenance simple and convenient. However, the diesel generator sets are also some disadvantages: ① only use liquid fuel, fuel prices, more expensive, so energy costs are higher. ② engine wear large, short-lived, more frequent maintenance. Operational stability and overload capacity than steam power plant is poor. ③ operation unit vibration and noise, and workers in poor operating conditions. ④ of the magnetic pole surface of the generator must have the brake coil, in order to facilitate the unit starts and stops.