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Pictures of the Future
The Magazine for Research and Innovation

Power Transmission

Reliable Power Supply in India

Siemens commissioned its to date built largest fully regulated classic SVC system with a reactive power range of one GVAr at the Ludhiana substation in the Indian state of Punjab.

India has to sate its vast hunger for energy and stabilize its power grid. To make this possible, Siemens is installing three reactive power compensators, including the most powerful such system in the world.

Siemens is helping India to improve its power grid. Ton accomplish this, the company is doing this by installing three large reactive power compensators to control the voltage in the power grid. Known as static VAR compensators (SVCs), these systems enable the grid to transport more energy and help to prevent power outages. Siemens has now built the world’s largest SVC in India. It can supply up to one gigavolt-ampere reactive (GVAr) of reactive power.

India requires huge amounts of energy. The country has to support its rapid economic growth and connect hundreds of thousands of its inhabitants to the power supply system for the first time. To do this, it is making massive investments in renewable energies and in high-voltage direct-current transmission (HVDCT) technology. This transmits large amounts of electrical energy over long distances with low losses. Siemens has already built large HVDCT facilities in India. In addition, the country is currently modernizing its completely overloaded power grid. Not only must the grid become more stable to increase the reliability of the electricity supply, it also has to become flexible so that it can handle the fluctuating amounts of renewable energy.

Making the Grid More Flexible

The key to modernizing the grid is to use flexible AC transmission systems (FACTS). These consist of a range of control systems for regulating the voltage, current, and phase angle of the energy in the grid. FACTS enable the flow of electricity in the grid to be actively influenced for the first time and fed along specific selected power lines. These systems are based on state-of-the-art power electronics and provide transient power within milliseconds in order to stabilize the grid voltage, damp oscillations, and prevent other disturbances. In this way, FACTS increase the grid’s capacity and make it less prone to disruptions. Siemens produces all of the main components for FACTS — including the transformers, valves, circuit breakers, and capacitors — itself and has been designing FACTS for a variety of requirements for years.

Known as static VAR compensators (SVCs), these systems enable the grid to transport more energy and help to prevent power outages.

Reactive Power as a Means of Control

Siemens’ FACTS product range includes static VAR compensators such as those being installed in India. Reactive power is the electric power that is used to generate electric and magnetic fields. It has to be transmitted in the grid along with the active power. Because long transmission routes and renewables increase the demand for reactive power, India needs corresponding solutions for expanding its grid as planned. Reactive power compensators are key control elements because they enable power companies to control the grid voltage. A distinction is made between serial and parallel compensators. Serial systems feed specific amounts of reactive power into the grid to improve a power line’s transmission capacity. SVCs, on the other hand, are parallel compensators. They primarily regulate the grid voltage at the feed-in points, increase grid stability, and make power transmission more reliable.

Siemens has manufactured most of the elements of the three new SVCs at its plant in India. The biggest compensator was put into operation at the Ludhiana transformer station in the Indian state of Punjab. The new system’s capacity is especially impressive, because it can supply up to one GAVr of reactive power. This makes it the most powerful regulated SVC ever built. The high performance pushes every component to its technical limits. To create the system, Siemens therefore took advantage of its extensive vertical integration. This enabled the company’s engineers to address many factors for optimally configuring the new system. A second, somewhat smaller SVC is in operation at the Kankroli transformer substation in Rajasthan. The third system will be installed later this year in the state of Jammu and Kashmir.

Christine Rüth