Abstract: A method to provide Primary Frequency Regulation to a steam turbine in a combined cycle plant that comprises storing energy in the form of internal energy of the steam contained within the piping and domes of the heat recovery boilers, and then using said energy when the power grid requires a sudden increase in output power. With the present method, the losses in power generation of the steam turbine, when said turbine is operating in the Primary Frequency Regulation mode, are reduced to a minimum. When the gas turbines in a combined cycle plant operate in PFR mode, the steam turbine reduces its output power because the gas turbines must operate below their rated power. The present method converts said decrease in output power of the steam turbine in a Spinning Reserve useful for PFR in said turbine. That is to say that the present method converts said Spinning Reserve in a rapid reserve, available after just a few seconds; if necessary, response times of less than 10 seconds can be attained.

Abstract: A method to provide Primary Frequency Regulation to a steam turbine in a combined cycle plant that comprises storing energy in the form of internal energy of the steam contained within the piping and domes of the heat recovery boilers, and then using said energy when the power grid requires a sudden increase in output power. With the present method, the losses in power generation of the steam turbine, when said turbine is operating in the Primary Frequency Regulation mode, are reduced to a minimum. When the gas turbines in a combined cycle plant operate in PFR mode, the steam turbine reduces its output power because the gas turbines must operate below their rated power. The present method converts said decrease in output power of the steam turbine in a Spinning Reserve useful for PFR in said turbine. That is to say that the present method converts said Spinning Reserve in a rapid reserve, available after just a few seconds; if necessary, response times of less than 10 seconds can be attained.