Methods, systems and apparatus for regulating frequency of generated power using flywheel energy storage systems with varying load and/or power generation

Abstract

A method for controlling AC frequency of electrical power being distributed to an electrical distribution network that is connected to one or more electrical loads and to one or more power sources includes: electrically coupling an energy storage sub-system to the electrical distribution network, said energy storage sub-system including one or more flywheel energy storage systems; and controlling operation of each of the flywheel energy storage systems responsive to the AC frequency of the electrical power, so the electrical storage subsystem injects or absorbs an amount of electrical energy into or from the electrical distribution network so as to regulate the AC frequency of the electrical power being distributed to the electrical distribution network so as to be at or about a desired AC frequency.

What is claimed is: 
     
         1 . A method for controlling AC frequency of electrical power being distributed to an electrical distribution network that is connected to one or more electrical loads and to one or more power sources, the frequency control method comprising:
 electrically coupling an energy storage sub-system to the electrical distribution network, said energy storage sub-system including one or more flywheel energy storage systems; and   controlling operation of each of the flywheel energy storage systems responsive to the AC frequency of the electrical power, so the electrical storage subsystem injects or absorbs an amount of electrical energy into or from the electrical distribution network so as to regulate the AC frequency of the electrical power being distributed to the electrical distribution network so as to be at or about a desired AC frequency.   
     
     
         2 . The frequency control method of  claim 1 , wherein said controlling comprises: controlling operation of each of the flywheel energy storage systems so as to change the amount of power being injected into or absorbed from the electrical distribution network by the energy storage sub-system by a determined amount when the AC frequency of the electrical power differs from the desired AC frequency, wherein the determined amount is determined by evaluating a difference between the total power being outputted by the one or more power sources and the total load imposed by the one or more electrical loads. 
     
     
         3 . The frequency control method of  claim 2 , wherein the difference between the total power and the total load and the difference between the AC frequency and the desired AC frequency are determined periodically and wherein said controlling includes controlling operation of each of the one or more flywheel energy storage systems responsive to the periodically determined differences. 
     
     
         4 . The frequency control method of  claim 1 , further comprising the step of
 determining a difference between a total power being outputted by the one or more power sources and a total load imposed by the one or more loads; and   wherein said controlling includes controlling operation of each of the flywheel energy storage systems of the energy storage sub-system so as to maintain the AC frequency at or about the desired AC frequency by one of
 increasing power being outputted by one or more flywheel energy storage systems when the determined difference is a negative value, or 
 decreasing power being outputted by the one or more FESS energy storage sub-system when the determined difference is a positive value. 
   
     
     
         5 . The frequency regulation method of  claim 1 , wherein said electrically coupling includes electrically coupling a plurality of energy storage sub-systems to the electrical distribution network, each of said plurality of energy storage sub-system including a plurality or more of flywheel energy storage systems. 
     
     
         6 . The frequency regulation method of  claim 1 , wherein the energy storage sub-system includes one of 10 or more flywheel energy storage systems or 10 or less flywheel energy storage systems. 
     
     
         7 . The frequency regulation method of  claim 5 , wherein each of the plurality of energy storage sub-systems includes one of 10 or more flywheel energy storage systems or 10 or less flywheel energy storage systems. 
     
     
         8 . The frequency regulation method of  claim 1 , wherein the energy storage sub-system further comprises an adjustable load, and wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load responsive to the total power being outputted and the total load so as the electrical storage sub-system outputs the amount of electrical energy to regulate the AC frequency. 
     
     
         9 . The frequency regulation method of  claim 8 , wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load so as to one of inject power into the electrical distribution network or absorb power from the electrical distribution network to regulate the AC frequency. 
     
     
         10 . The frequency regulation method of  claim 9 , wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load so that a determined amount of power is diverted from the adjustable load so as to be outputted by the system to the electrical distribution network. 
     
     
         11 . The frequency regulation method of  claim 10 , wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load so that a determined amount of power also is outputted from the plurality of flywheel energy storage systems and thus outputted by the system to the electrical distribution network. 
     
     
         12 . The frequency regulation method of  claim 9 , wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load so that a determined amount of power is absorbed by the adjustable load from the electrical distribution network. 
     
     
         13 . The frequency regulation method of  claim 12 , wherein said controlling includes controlling operation of each of the flywheel energy storage systems and the adjustable load so that a determined amount of power also is absorbed by the plurality of flywheel energy storage systems from the electrical distribution network. 
     
     
         14 . An AC frequency regulation system for regulating AC frequency of electrical power being distributed to an electrical distribution network that is connected to one or more electrical loads and to one or more power sources, the system comprising:
 an energy storage sub-system electrically coupled to the electrical distribution network, the energy storage sub-system comprising a plurality of flywheel energy storage systems; and   a controller being operably coupled to each of the flywheel energy storage systems in the energy storage sub-system and being responsive to frequency regulation signals generated external to the system,   wherein the controller is configured and arranged to control operation of each of the plurality of flywheel energy storage systems in the energy storage sub-system responsive to the frequency regulation signals, so the system injects or absorbs an amount of electrical energy into or from the electrical distribution network so as to regulate the AC frequency of the electrical power being distributed to the electrical distribution network so as to be at or about a desired AC frequency.   
     
     
         15 . The AC frequency regulation system of  claim 14 , wherein the plurality of flywheel energy storage systems in the energy storage sub-system are arranged to form an array and wherein the array of the plurality of flywheel energy storage systems is controlled by the controller so that the array one of injects or absorbs power. 
     
     
         16 . The AC frequency regulation system of  claim 14 , wherein the system further comprises an adjustable load that is operably coupled to the controller and wherein the controller is configured and arranged so as to control at least one of the adjustable load and the plurality of flywheel energy storage systems in the energy storage sub-system so the system selectively injects or absorbs power responsive to the frequency regulation signals. 
     
     
         17 . The AC frequency regulation system of  claim 16 , wherein the system controls the adjustable load and the array of flywheel energy storage systems so that a determined amount of power is diverted from the adjustable load so as to be injected by the system to the electrical distribution network. 
     
     
         18 . The AC frequency regulation system of  claim 17 , wherein the system controls the adjustable load and the array of flywheel energy storage systems so that a determined amount of power also is outputted from the array of flywheel energy storage systems so as to be injected by the system to the electrical distribution network. 
     
     
         19 . The AC frequency regulation system of  claim 16 , wherein the system controls the adjustable load and the array of flywheel energy storage systems so that a determined amount of power is absorbed by the adjustable load from the electrical distribution network. 
     
     
         20 . The AC frequency regulation system of  claim 16 , wherein the system controls the adjustable load and the array of flywheel energy storage systems so that a determined amount of power is absorbed by the array of flywheel energy storage systems from the electrical distribution network.