# Mr Electro

Hi Mr Electro family!! This is an educational website for electrical stream ( Electrical engineering, Diploma student and PreDiploma students) . This is mainly focused for those students who are waiting for Government jobs like LokSewa Aayog PSC, NEA, CANN NTC for level 3, level 4, level 5 and level 7 and also private jobs.

## Monday, July 25, 2022

Have you think how electricity come from power plant to our house? Then it is best article for you. There are many types of power plant in the system and they are far from them so they need to connect and supply power to the whole system. For that all generating station need to be interconnected and supply more power to different parts of costumers. This interconnection process of alternator or generator is called parallel operation. Here we go describe about generator synchronization || Parallel Operation of Generators which include bright lamp method of synchronization, dark lamp and bright lamp method, amp dark method of synchronization, bright lamp method, three lamp method of synchronization, three dark lamp method.

# What is Parallel Operation of generator or Generator synchronization?

Alternators/generator are a synchronous machine which converts mechanical power into electrical power by the process of electromagnetic induction. It can operates in isolate or in a group (i.e. in parallel) but in general practice, mostly there are many alternators in a system and the system are interconnected in the network which means all alternators are connected in parallel which is known as infinite busbars. Infinite busbars is a power system of a large power from a large number of alternator connected in parallel which provides same voltage and frequency. An arrangement of alternators connected in parallel for optimum efficiency and greater reliability. When the load increase beyond the generated capacity of an alternator, then others alternators will carry the load. Similarly when load demand decreased, an alternator with high efficiency will be used. That's why it is necessary to be connected all generator in a system / interconnected system.

### Why is it necessary for alternator or generator Parallel Operation?

There are many advantages for it. They are :-

• More alternator can provide more power or can serve more loads.
• In case of a alternator breakdown, others can serve loads so that no interruption of power supply. Also in scheduled maintenance, power supply will be continue.
• During light load condition, alternator will operates on full load i.e. high efficiency or, an alternator with high efficiency will operate which will increase the efficiency of the system.
• The operating cost of generator will be reduced in parallel operation.
• In future a no of alternators can be added in the infinite busbars to meet future loads.

### Necessary conditions for parallel operation

In a power system, a lot of alternators/generator are connected in parallel with each others and the process of connecting in parallel is called Synchronizing. There are necessary condition for synchronization and these need to be followed for parallel operation. They are following condition for parallel operation / synchronization:-

• The incoming machine voltage and phase sequence of busbars voltages must be same.
• The frequency of incoming machine's generated voltage and the frequency of busbars voltage must be same.
• The busbars voltage and incoming voltage of incoming machine must be in phase.
• The terminal voltage of incoming machine and the terminal voltage of alternator that run in parallel must be same.
If synchronization is not done perfectly, then there will be small to large energy loss i.e. power flow in opposite direction which will leads power system collapsed or damage alternators in the power system.
The machine which are already carry load are known as running machine , while the alternator that is going to connected in system is called incoming machine. The incoming machine which is going to connected be connected to the system is same for all others incoming machine.
Note :- A alternator which is not running (i.e. stationary) should not connected to the live busbars because this will result short circuit in the network due to zero induced emf at standstill condition.

### Generator Synchronization Methods

There are mainly two type for Generator Synchronization operation. They are as follows :-
• Synchronizing lamps
• Three bright lamp method
• Two-bright one dark lamp method
• Synchroscope