A system contains a double fed induction machine having a stator and a rotor, a fly wheel coupled to the rotor, and a control device for providing a rotor voltage and a rotor current to the rotor. The control device is connected to the rotor and the stator and is capable of generating the rotor voltage and rotor current in response to an electrical signal that is applied to the stator. The control device has a multilevel converter and a control unit for controlling the multilevel converter.

A system contains a double fed induction machine having a stator and a rotor, a fly wheel coupled to the rotor, and a control device for providing a rotor voltage and a rotor current to the rotor. The control device is connected to the rotor and the stator and is capable of generating the rotor voltage and rotor current in response to an electrical signal that is applied to the stator. The control device has a multilevel converter and a control unit for controlling the multilevel converter.

The present invention relates to a power management system (PMS) for multiple energy storage systems (ESS) that is for integrated management of the system having multiple ESS for controlling a frequency and having a hierarchical control structure. The PMS for ESS comprises: a plurality of ESS; a local management system (LMS) for managing one or more ESS of the plurality of ESS for each local unit; an ESS Controller (ESSC) for general management of the LMS, judging a state of the LMS and determining an output value of one or more ESS in the LMS, and transmitting the determined output value to the respective ESS; and a PMS for general management of the entire system comprising the plurality of ESS, the LMS and the ESSC, judging the state of the entire system and participating in a power grid frequency control market through a grid operator contract, controlling the output of the LMS, and adjusting a control parameter for output control.

A frequency support system arranged for providing frequency support to an AC grid. The system includes an ES arrangement, and a bi-directional DC/AC power electronic converter interface configured for connecting the ES arrangement with the grid. The ES arrangement includes a plurality of series connected ES groups, each ES group including a plurality of parallel connected ES modules, each ES module including an energy storage interfaced by a bi-directional power electronic ES converter configured for connecting the ES with a DC side of the converter interface.

A frequency support system arranged for providing frequency support to an AC grid. The system includes an ES arrangement, and a bi-directional DC/AC power electronic converter interface configured for connecting the ES arrangement with the grid. The ES arrangement includes a plurality of series connected ES groups, each ES group including a plurality of parallel connected ES modules, each ES module including an energy storage interfaced by a bi-directional power electronic ES converter configured for connecting the ES with a DC side of the converter interface.

A stored energy power source uses a wound-rotor induction machine (WRIM) to receive energy from a prime mover via a rotating shaft, provide magnetization reactive energy from a self-excited AC capacitor bank, store the energy in N energy storage elements (ESEs) via tertiary windings, and discharge the ESEs to deliver energy via a secondary winding to a load producing output. Each discharging ESE contributes to a total flux at the secondary winding to sum the individual ESEs voltages. These voltages can be stepped up or down by a transformation ratio between the secondary winding and each of the tertiary windings. A flywheel may be coupled to the shaft to store and delivery kinetic energy. Load factor power control can be used to stabilize the output voltage. The source may be configured to allow for the bi-directional flow of energy between the ESEs, the flywheel and the load. The WRIM provides a safe, reliable and efficient system to provide high-level AC and DC output voltages.

A stored energy power source uses a wound-rotor induction machine (WRIM) to receive energy from a prime mover via a rotating shaft, provide magnetization reactive energy from a self-excited AC capacitor bank, store the energy in N energy storage elements (ESEs) via tertiary windings, and discharge the ESEs to deliver energy via a secondary winding to a load producing output. Each discharging ESE contributes to a total flux at the secondary winding to sum the individual ESEs voltages. These voltages can be stepped up or down by a transformation ratio between the secondary winding and each of the tertiary windings. A flywheel may be coupled to the shaft to store and delivery kinetic energy. Load factor power control can be used to stabilize the output voltage. The source may be configured to allow for the bi-directional flow of energy between the ESEs, the flywheel and the load. The WRIM provides a safe, reliable and efficient system to provide high-level AC and DC output voltages.

A station constituted of: a control circuit; a first and a second bi-directional converter, each in communication with the control circuit, each arranged to be coupled to a respective plug-in electrical vehicle at a respective first port thereof; and a connection to an AC grid, wherein the control circuit is arranged to: draw electrical energy from a first plug-in electrical vehicle coupled to the first port of the first bi-directional converter; and provide at least some of the drawn electrical energy to a second plug-in electrical vehicle coupled to the first port of the second bi-directional converter.

A station constituted of: a control circuit; a first and a second bi-directional converter, each in communication with the control circuit, each arranged to be coupled to a respective plug-in electrical vehicle at a respective first port thereof; and a connection to an AC grid, wherein the control circuit is arranged to: draw electrical energy from a first plug-in electrical vehicle coupled to the first port of the first bi-directional converter; and provide at least some of the drawn electrical energy to a second plug-in electrical vehicle coupled to the first port of the second bi-directional converter.

Systems and methods may use a low speed controller in addition to an economic optimizer to achieve long-term objectives without significantly disrupting or destabilizing an electrical system. Specific long-term objectives include maximizing a capacity factor incentive and regulating battery degradation, but the methods and systems herein can be extended to more long-term objectives. A low speed controller can adjust one or more parameters of a cost function based on the relation between the projected state of the electrical system and the one or more parameters to effectuate a change to the electrical system to attempt to comply with the long-term objective.