Abstract: A method of controlling a permanent magnet turbogenerator/motor includes providing a protected load connected in parallel with the turbogenerator/motor through a pulse width modulated inverter configured in a first operating mode to supply controlled current from the turbogenerator/motor to a utility electrical power source, and selectively connected to the utility electrical power source through an isolation device, monitoring the utility electrical power source, and automatically disconnecting the protected load from the utility electrical power source while reconfiguring the pulse width modulated inverter in a second operating mode to supply controlled voltage to the protected load when a fault is detected in the utility electrical power source.

Abstract: A method and system to automatically restart a permanent magnet turbogenerator/motor when a fatal fault is detected. The automatic restart logic includes time constraints and limitations on the number of iterations, and is useful regardless of whether the permanent magnet turbogenerator/motor is in a grid connect mode or a standalone mode, and regardless of how the fatal fault originates or is detected. Additional control logic is utilized to handle grid transients and over load conditions to prevent a fatal fault from occurring by using time constraints and an iterative process, together with a brake resistor to control DC bus voltage.

Abstract: A system and method for modular control of a multi-fuel turbogenerator include separate controllers for controlling fuel supplied to the combustor and power output from the generator. The power controller generates a fuel command based on the required turbine exhaust temperature, where the fuel command is independent of the particular fuel being used. Fuels may include natural gas, diesel, propane, waste gas, or gasoline, for example. The power controller communicates the fuel command and the airflow or calculated air/fuel ratio to the fuel controller which selects an appropriate mode of operation for the injectors. Injector operating modes include one or more pilot modes where fuel is not mixed with air prior to combustion, and one or more premix modes where fuel is highly mixed with air prior to combustion.

Abstract: A method and system to automatically restart a permanent magnet turbogenerator/motor when a fatal fault is detected. The automatic restart logic includes time constraints and limitations on the number of iterations, and is useful regardless of whether the permanent magnet turbogenerator/motor is in a grid connect mode or a standalone mode, and regardless of how the fatal fault originates or is detected. Additional control logic is utilized to handle grid transients and over load conditions to prevent a fatal fault from occurring by using time constraints and an iterative process, together with a brake resistor to control DC bus voltage.

Abstract: A multi-injector combustion system in which a brake resistor is utilized to provide a minimum load for the combustor system during idle or low power operation of the permanent magnet turbogenerator/motor and also to absorb power during transients to prevent flame out of the combustor. In addition, during single injector operation, a relighting method and system are provided to relight the combustor and prevent the necessity of a complete shutdown of the system. The method and system includes switching between the multiple injectors to find the most stable injector in single injector operation.

Abstract: The power meter, required in most utility grid connectged applications to measure load consumption, is utilized to provide a feedback to an associated turbogenerator power controller, providing a control system for peak shaving, load following, reactive power control, reverse flow protection and load analysis for scheduled turbogenerator operation. This control system operates with simple discrete signals for peak shaving operation, to more complex pulse signals for load following, to load profile analysis and scheduled operation based on a microprocessor based serial input from a digital power meter.

Abstract: A method and system to automatically restart a permanent magnet turbogenerator/motor when a fatal fault is detected. The automatic restart logic includes time constraints and limitations on the number of iterations, and is useful regardless of whether the permanent magnet turbogenerator/motor is in a grid connect mode or a standalone mode, and regardless of how the fatal fault originates or is detected. Additional control logic is utilized to handle grid transients and over load conditions to prevent a fatal fault from occurring by using time constraints and an iterative process, together with a brake resistor to control DC bus voltage.

Abstract: A multi-injector combustion system in which a brake resistor is utilized to provide a minimum load for the combustor system during idle or low power operation of the permanent magnet turbogenerator/motor and also to absorb power during transients to prevent flame out of the combustor. In addition, during single injector operation, a relighting method and system are provided to relight the combustor and prevent the necessity of a complete shutdown of the system. The method and system includes switching between the multiple injectors to find the most stable injector in single injector operation.

Abstract: A turbogenerator/motor control system having a plurality of proportional integral control loops including a fuel command control loop and a current command control loop. The exhaust gas temperature of the gas turbine of the turbogenerator/motor is maintained at a constant value with stability is achieved by varying the sampling times of the different proportional integral controls within the control loops.