Phase Shifting Transformers can Optimizes the Transmission Infrastructure, Reduces the Losses, Improves grid Stability, reduces Congestion, Changes the Active & Reactive Power flow Both in Magnitude and Direction

In most of the developed countries, there is a very small gap say nil in power generation and the power consumption (Loads connected) and therefore Transmission networks are also not growing much. Little bit addition of small renewable generation or replacement of the aged generation do not justify the addition of transmission network. It is therefore necessary to use the existing network exploiting new devices at meager cost, however the scenario in developing countries is entirely different. Developing countries are struggling to get the power at any cost and have no time to think about the optimization. Any way the increase in the transmission/distribution infra structure will pave the way over a period of time when there will be no right of way left to develop or will not be so easy to develop.

Considering Indian Power System which is growing with a rapid pace and another 100000 MW is planned to be added in next 5 year plan. With the result, the transmission & distribution has to increase many fold. The optimal use of existing infrastructure needs to be done in order to contain investment. It is therefore necessary to load the existing lines to optimal capacity rather than providing the additional corridor where ever it is not absolutely necessary. For reliability reasons in critical areas providing additional transmission corridor can not be ignored. Overloading of subsystem in a power system some times may pose stability issues, which may lead to unwanted tripping, equipment failures which will result long repair/replacement cycle and heavy revenue losses. Under these conditions, to ensure economical and reliable operation of the grid, power through the lines should be controlled within their capabilities. Application of HVDC systems becomes much simpler to achieve control of both active and reactive power however at all situations the economy may not justify such applications. Application of FACTS(Flexible Alternating Current Transmission Systems) devices could find its place, which are the off shoots of HVDC systems. Most of such devices are location specific and therefore should be carefully chosen and rated for the specific requirements Phase shifting transformer is one of the device from FACTS family, which can be used for power flow control in a network. For demonstrating the ability of the phase shifting transformer in regulating the power flow in an alternate transmission network, various cases involving simulation of Maharashtra zone, Uttar Pradesh zone, a part of Andhra Pradesh zone and inter regional power control of the Indian grid are considered. From power flow solution, various overloaded lines and the alternate under loaded lines are identified. Different cases are simulated to regulate the power using phase shifting transformer in to the actual network of the Indian Grid.