Advantages and Disadvantages of Interconnected Power System

Advantages and Disadvantages of Interconnected Power System

Advantages of Interconnected Power System

Interconnected power systems have many advantages which is Described below:

• ✓ An important advantage of interconnected system is that the peak load of the power station can be exchanged.

Advantages and Disadvantages of Interconnected Power System

• ✓ If the load curve of a power station shows a peak demand that is greater than the rated capacity of the plant, then the excess load can be shared by other stations interconnected with it.

• √ The interconnected system makes it possible to use the older and less efficient plants to carry peak loads of short durations.

• √ Although such plants may be inadequate when used alone, yet they have sufficient capacity to carry short peaks of loads when interconnected with other modern plants.

• √ Therefore, interconnected system gives a direct key to the use of obsolete plants.

• ∆ The interconnected system makes the operation of concerned power stations quite economical.

• ∆ It is because sharing of load among the stations is arranged in such a way that more efficient stations work continuously throughout the year at high load factor and the less efficient plants work for peak load hour only.

• ~ The load curves of different interconnected stations are generally different.

• ~ The result is that the maximum demand on the system is much reduced as compared to the sum of individual maximum demands on different stations.

• ~ In other words, the diversity factor of the system is improved, thereby increasing the effective capacity of the system.

• * Every power station is required to have a standby unit for emergencies.

• * However,when several power stations are connected in parallel,then reserve capacity of the system is much reduced.

• * This increases the efficiency of the system.

• -> The interconnected system increases the reliability of supply.

• -> If a major breakdown occurs in one station, continuity of supply can be maintained by other healthy stations.

Disadvantages of Interconnected Power System

There are many disadvantages of interconnected Power system which is mentioned below.

✓ The generators of all the interconnected generating stations must operate the same at frequency and in a synchronized manner.

✓ During the heavy load condition some generators go out of step due to this synchronization breakup.

✓ And finally complete system goes out of step is also called black out condition.

>> In the interconnected power system to control the system reactive power, tie lines are used.

>> Expense of tie lines for construction of interconnecting transmission line between generating stations.

√ An interconnected system use circuit breaker to isolate the faulty part from the healthy part during the fault condition.

√ For high voltage power system, higher rating circuit breaker is used.

√ During the large flow of current on transmission line under faulty condition with a consequent increase in capacity of circuit breakers therefore expensive circuit breaker are required with interconnected power system.

√ Hence cost of circuit breakers increase.

∆ Adequate metering and instrumentation is needed at different levels.

∆ It is necessary to install sequential recorders, disturbance recorder, time of

day meters etc.