# 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.

## Sunday, July 31, 2022

We have already discuss about  parallel operation of alternator/generator and its condition. Also we had described about synchronizing methods of three lamp method. Here we are going to discuss about Synchroscope method || Synchroscope method of Synchronization in parallel operation for a number of generator. For small machine, three lamps method is cheap and good but for large machine in a power system, it is generally processed by using synchroscope which will synchronize automatically by using computer. Phase sequence of alternator is checked at the time of installation. The voltage of incoming machine and busbar is compared and the pointer on it indicates the phase difference between the voltage of busbar and incoming machine.

# Operation of Synchroscope method of Synchronization

When the frequency of both incoming alternator and busbar is same, the pointer will be at standstill position. And the movement of pointer gives the information about whether the frequency of incoming machine is high or low which also can be known as the incoming generator is running too fast or slow. The speed of rotation of pointer indicate the difference between the frequency of incoming generator and busbar. Now the phase position and frequency of incoming machine is controlled by adjusting the prime mover input. When the pointer moves slowly (frequency of incoming machine is nearly same to busbar’s frequency) and phase through the zero-phase point (frequency of incoming machine need to higher slightly than busbar because power flow from high voltage to low). After that, the circuit breaker/switches are closed and incoming machine is connected to busbar.

(Note: synchro scope is connected to only one phase so it only check for a phase i.e. no information about sequence.)

### Description of its figure

A simple figure of synchroscope is given below which is just used to understand the operating process of it. There is a pointer which will be fluctuating as frequency of incoming and infinite bus is difference and that fluctuating speed depends on how much the frequency is different. There is "slow" on left and "fast" on right side which mean, the incoming machine's frequency is fast or slow as compared to infinite bus. So that the frequency can be increased or decreased from that information. Hence, it is easy to use as compare to 3 bulb methods.

In real practice, both 3 bulb as well as synchroscope both methods are used. For small and easy system, it is best to use because it is cheap and easy to handle. But in a power system with large no of generator, a complex system is formed where there is a lot of instruction about connect or disconnect the generator to system. For manual process (3 bulb method) will be very tedious and may be human error occurs while connecting to infinite busbar so synchroscope is used while connecting to the system automatically or manually which is very helpful in complex as well as large system for synchronizing.

### Real practice for synchronizing methods

In context of Hydropower which is connected to grid, almost all generator in a hydropower is connected to synchroscope machine for synchronizing. A synchroscope machine is used synchronizing the only one phase of the system. That mean's, we have to use 3 synchroscope for a generator while connecting to the infinite bus by using synchronizing method so it will increase the cost of process as compared to three bulb method.

On conclusion, we have discussed about 2 types of synchronizing methods one is 3 bulbs method and another is synchroscope method. For small system with low budget, we can use three bulb method on other hand for big and high budget system, we can use synchroscope method.