CHP: Very often the demand for electricity and heat are changing seasonally and daily. Therefore it is advantageous to operate the steam turbine in a flexible way. ST trains may consist of several cylinders and connection and disconnection of one of the cylinders, depending whether the heat extraction or peak electricity production is necessary, may make the CHP plant to be able to respond the market demand changes simultaneously.
CCGT: CCGT is one of the most modern power plant concepts with a very high efficiency. CCGT can be single shaft or multi shaft. Single shaft with a connecting device between ST and the double driven generator offers similar efficiency as a multi shaft one but requires less equipment, less controls and less machinery room and thus less investment. Talking about multi shaft, ST train cylinders can be also flexible connectable similar to CHP example above.
Reactive power correction: Peak power and Uninterruptable Power Supply (UPS) plants can be used while idle to provide a reactive power to the grid with existing rotating equipment. For this a device to disconnect the driving machine from the generator once
it is synchronized with the grid can be used. Generator can work as synchronous condenser providing lagging or leading VArs to the grid and as soon as the real power is needed it will be instantly connected with the driving machine and will be able to generate electricity to the grid.
Combined Cycle Gas Tur-bine (CCGT) Power Plant suppliers configure turbine generators in a number of different ways. Single shaft arrangements where a gas turbine and a steam turbine drive a single generator are often preferred because they offer a more compact plant at a lower cost. Many include an SSS Clutch to disconnect the steam turbine to allow the gas turbine and generator to be operated independently of the steam turbine.
Combined Heat and Power (CHP) Plants are flexible by design. They offer the capability to accommodate daily or seasonal changes in demand for both heat and power. In order to achieve this, SSS Clutches can be arranged to connect and disconnect part of a steam turbine section from the generator without interrupting power generation of the remaining steam turbine section.
If an SSS Clutch is fitted on a peak load set between the gas turbine and the generator, the generator can earn money, even with the gas turbine at rest. When the turbine is shut down, the clutch automatically disengages leaving the generator rotating for synchronous power factor correction, voltage control, or spinning reserve. SSS Clutches have been used for synchronous condensing operation since 1964.
Pumped Air Storage is used to store low cost electrical energy as compressed air so that it can be used to produce electricity at times of peak demand. SSS Clutches allow a single generator to be used for both compression and generation to achieve reduced cost and plant footprint with a simple changeover between operating modes. The highest power automatic clutch for Pumped Air Storage in the world is an SSS Clutch that transmits 321,000kW at 3,000 RPM.