Indian Power Generation sources have all along have been predominantly coal based power plants. With the steadily increasing influx of Renewable Energy(RE) power in to the Transmission Grid , the Indian Transmission Grid is expected to see major disturbances in the coming times. RE power share in the total power generation at any point of time, shall be touching 30-35% soon. As this threshold is broken and the integration of RE Power share’s in the total power mix will create system disturbances. Solutions like Phase Shifting Transformers to optimize the transmission capacities of existing systems would become more and more popular.
Scaling up variable RE generation requires grid expansion and system upgradation so that power systems can access high-quality solar and wind resources. Apart from the challenges which the existing Power plant operators are likely to face to stymie the effects of rising share of RE power in the power generation mix like Flexible Operation of Power Plants, Energy storage solutions etc., the challenges shall also be there in the system integrations.
The first principle in Transmission Systems Studies and system upgradation points to putting up new transmission infrastructure in place. However, there is a unexplored solution of putting up of Phase Shifting Transformer in the transmission line connecting two otherwise independent power systems.
The two principal configurations of deployment of Phase Shifting Transformers(PST) are:
- Two Parallel transmission systems where in one system PST can be deployed.
- Single transmission line which is used to connect two otherwise independent power systems.
The idea of deploying PSTs is to primarily maximize the capacity of existing transmission systems rather than putting money in to new transmission schemes.
Delta V is introduced by PSTs either as Advanced Phase Angle or Retard Phase Angle to control the voltages.
The PSTs can be designed taking following considerations in to account:
- Throughput Power and Phase Shift angle requirement
- Rated Voltage
- Short Circuit capability of the connected systems
- Shipping limitations
- Load Tap Changer performance specifications
As the share of Solar and Wind power grows in the total power generation mix, we would be seeing more and more utilities would resort to such innovative technologies for which ready references are already available.