Top 5 Advantages of Parallel Operation of Generators or Alternators

Parallel Generators Cover

As every field of life becomes more dependent on electric power to operate and grow, backup power systems, like generators, are playing a progressively vital role in guaranteeing uninterrupted supply of power. Generator selection greatly depends on the amount of backup power needed for a specific application. An application may need minimal supply of backup power to ensure uninterrupted functioning or it may need full power of the backup system. It is hard to find a generator that matches the application requirement exactly. This is one area where parallel generators can shine.

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All of us know that there are two types of connections, series & parallel.

Series Connection

Series connection is formed by cascading the impedance together.

series connection
series connection

Hence in series circuit, voltage gets divided & current flowing through each component is same.

Parallel Connection

Parallel connection is formed as follows:

parallel connection
parallel connection

Hence in parallel circuit, voltage across each component remains constant & current gets divided.

Everywhere in an electrical system, we require a constant voltage to operate power systems in an effective and efficient manner.

Consider the example of your household electrical connections. Your wiring at home is similar to a small power system, wherein there is only one power source & numerous loads to boot. In order to have the desired operation of protective device, you need to supply it with the rated voltage & that is only possible with a parallel connection.

Similarly, in huge power systems, we interconnect various generators together at the same voltage level, same frequency & same phase sequence.

When a large number of alternators or synchronous generators are connected in parallel to an infinite bus bar system having a constant terminal voltage, constant bus bar frequency and very small synchronous impedance, then this kind of connection is known as parallel operation of alternators. Parallel operation of alternators is often called as synchronizing. Synchronization can be achieved using various methods like the synchronization lamps, relays and even a synchroscope. These will be explained in more detail in a future blog.

Advantages of Parallel Operation of Alternators:

To learn the advantages and precautions of parallel operation, click on Advantages of Parallel Operation of Alternators.


Economically, a well-designed system provides backup power and variable output. Parallel generators become a cost-effective solution when the output power capacity of standard generator units, available in the market, greatly exceeds the minimum requirement or falls short of the maximum requirement. The synchronization of generators in parallel brings great advantages as we discussed in this blog. Parallel generators provide the maximum output when the power demand peaks and minimum output when the load necessities are low. Hence, parallel generators increase the reliability of power systems and make them more efficient.

Let us know if you have any queries regarding this topic and do provide us with your feedback in the comments.

About The Author

Abdur Rehman is a professional electrical engineer with more than eight years of experience working with equipment from 208V to 115kV in both the Utility and Industrial & Commercial space. He has a particular focus on Power Systems Protection & Engineering Studies.

Abdur Rehman is the CEO and co-founder of and creator of GeneralPAC by AllumiaX. He has been actively involved in various roles in the IEEE Seattle Section, IEEE PES Seattle, IEEE Region 6, and IEEE MGA.

Leaders in Industrial & Commercial Power Systems Engineering