An exemplary power system may include an electric machine with multiple sets of stator windings, each set of windings being coupled through a separate switch matrix to a common voltage bus, and each of which may be spatially arranged in full pitch around the stator such that stator flux harmonics are substantially reduced. The reduced stator flux harmonics may be associated with phase current harmonic content. In an example application, such power systems may operate in a generating mode to transfer mechanical energy to electrical energy on a DC voltage bus. In some illustrative embodiments, the power system may provide both high-power and high-speed (e.g., 1MW at 8000 rpm or above) motoring and/or generating capability suitable, for example, for on-board (e.g., marine, aviation, traction) power systems.

Electromechanical energy conversion systems

Combined thermal and compressed air storage systems are provided that utilize an exhaustless heater, such as a thermal storage unit, to provide power with enhanced efficiency. Compressed air is heated by the thermal storage unit prior to entering a turbine, which powers an electrical generator. In various embodiments, ambient air temperature, turbine exhaust or other types of waste heat are used to preheat the compressed air prior to the compressed air entering the thermal storage unit, thereby further increasing system efficiency.

Thermal and compressed air storage system

The invention relates to methods and systems for the storage and recovery of energy using open-air hydraulic-pneumatic accumulator and intensifier arrangements that combine at least one accumulator and at least one intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits.

Systems and methods for energy storage and recovery using compressed gas

The invention relates to systems and methods for rapidly and isothermally expanding and compressing gas in energy storage and recovery systems that use open-air hydraulic-pneumatic cylinder assemblies, such as an accumulator and an intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits. The systems use heat transfer subsystems in communication with at least one of the cylinder assemblies or reservoir to thermally condition the gas being expanded or compressed.

Systems and methods for energy storage and recovery using rapid isothermal gas expansion and compression

Backup energy systems utilizing compressed air storage (CAS) systems and bridging energy systems to supply backup power to a load are provided. During a power failure, the bridging energy system provides backup power to the load at least until the CAS system begins supplying adequate power. In various embodiments, backup power capability is enhanced through the use of one or more exhaustless heaters, which are used to heat compressed air. The compressed air, in turn, drives a turbine which is used to power an electrical generator. In various embodiments, ambient air heat exchangers or other types of heat exchangers are used to heat compressed air prior to the compressed air being routed to the turbine, thereby increasing system efficiency. Backup power and backup HVAC are also provided by utilizing turbine exhaust, heat exchangers and various resistive heating elements.

Systems and methods for providing backup energy to a load

A method is provided to ensure that a combustion turbine power generation system may operate at maximum allowable power at elevated ambient temperature and/or at low air density. The method includes providing at least one combustion turbine assembly including a compressor, an expansion turbine operatively associated with the compressor, an upgraded generator coupled with the expansion turbine; a combustor feeding the expansion turbine; flow path structure fluidly connecting an outlet of the compressor to an inlet of the combustor; a compressed air storage; a charging compressor for charging the air storage; charging structure fluidly connecting an outlet of the charging compressor with an inlet to the air storage; connection structure fluidly connecting an outlet of the air storage to an inlet of the combustor; and valve structure associated with the connection structure and the charging structure to control flow through the connection structure and the charging structure, respectively. The valve structure is controlled to selectively permit one of the following modes of operation: (1) a combustion turbine mode of operation wherein air compressed from the compressor moves through the flow path structure to the combustor feeding the expansion turbine such that the expansion turbine drives the generator, (2) a compressed air augmentation mode of operation wherein compressed air from the air storage is supplied through the connection structure to the combustor in addition to the compressed air passing through the flow path structure to the combustor, which increases mass flow of compressed air and gas to the expansion turbine and thus permits the upgraded generator to provide an increased power due to the additional compressed air suppled to the expansion turbine, and (3) an air storage charging mode of operation wherein compressed air from the charging compressor moves through the charging structure to charge the air storage.

Michael Nakhamkin

Papers

Method of operating a combustion turbine power plant having compressed air storage