Abstract: A system includes a generator configured to be electrically coupled to a grid, an engine configured to drive the generator, and a solid state generator coupled between the grid and an energy storage device. The system further includes a bias controller configured to detect a frequency of the grid and to responsively provide a bias signal to a speed controller of the engine. The bias controller may include a frequency bias controller configured to generate a frequency bias load sharing signal responsive to the detected frequency of the grid and a load sharing controller that receives the frequency bias load sharing signal and that generates the bias signal responsive to the load sharing signal.

Abstract: A system includes a break-before-make automatic transfer switch (ATS) configured to selectively couple a utility grid and at least one distributed generator (e.g., a plurality of paralleled generators) to a load bus such that, in a state transition of the ATS, the utility grid and the at least one distributed generator are both disconnected from the load bus before the utility grid or the at least one distributed generator is connected to the load bus. The system further includes at least one converter configured to be coupled to the load bus and configured to provide power to the load bus during the state transition of the ATS.

Abstract: A system includes a break-before-make automatic transfer switch (ATS) configured to selectively couple a utility grid and at least one distributed generator (e.g., a plurality of paralleled generators) to a load bus such that, in a state transition of the ATS, the utility grid and the at least one distributed generator are both disconnected from the load bus before the utility grid or the at least one distributed generator is connected to the load bus. The system further includes at least one converter configured to be coupled to the load bus and configured to provide power to the load bus during the state transition of the ATS.

Abstract: A system includes a generator configured to be electrically coupled to a grid, an engine configured to drive the generator, and a solid state generator coupled between the grid and an energy storage device. The system further includes a bias controller configured to detect a frequency of the grid and to responsively provide a bias signal to a speed controller of the engine. The bias controller may include a frequency bias controller configured to generate a frequency bias load sharing signal responsive to the detected frequency of the grid and a load sharing controller that receives the frequency bias load sharing signal and that generates the bias signal responsive to the load sharing signal.

Abstract: A system includes a generator configured to be electrically coupled to a grid, a transmission configured to mechanically couple the generator to a prime mover, a converter circuit configured to be electrically coupled between the grid and an energy storage device, and a controller configured to control the converter circuit and the transmission. The controller may operate the converter circuit to source or sink power in response to a change on the grid meeting a criterion. The controller may be further configured to adjust a transmission ratio of the transmission based on a demand on the generator. The controller may also be configured to cause the transmission to mechanically decouple the generator from the prime mover while maintaining an electrical coupling of the generator to the grid so that the mechanically decoupled generator can contribute current to a fault on the grid.

Abstract: An apparatus includes a rack including a plurality of vertically-stacked battery shelves and a vertically extending pipe disposed adjacent the rack. The apparatus further includes a plurality of ports fluidically coupled to the pipe and spaced apart along a length of the pipe, respective ones of the ports configured to direct an extinguishing agent from the pipe towards respective ones of the shelves.

Abstract: A system includes at least one generator coupled to an island grid, at least one energy storage unit and at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid. The system further includes a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point. The at least one generator may include a control system configured to match generator output to the load and the control circuit may be configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.

Abstract: A system includes a converter configured to be coupled between an energy storage unit and a grid and a control circuit configured to detect frequency and voltage variations of the grid and to responsively cause the converter to transfer power and reactive components to and/or from the grid. The control circuit may implement a power control loop having an inner frequency control loop and a reactive component control loop having an inner voltage control loop. The control circuit may provide feedforward from the inner frequency control loop to the inner voltage control loop to inhibit reactive component transfer in response to a voltage variation deviation of the grid due to a power transfer between the energy storage unit and the grid.

Abstract: A system includes a generator (110) configured to be electrically coupled to a grid (10), a transmission (120) configured to mechanically couple the generator (110) to a prime mover (130), a converter circuit (140) configured to be electrically coupled between the grid (10) and an energy storage device (150), and a controller (160) configured to control the converter circuit (140) and the transmission (120). The controller (160) may operate the converter circuit (140) to source or sink power in response to a change on the grid meeting a criterion. In further embodiments, the controller (160) may be further configured to adjust a transmission ratio of the transmission (120) based on a demand on the generator (110).

Abstract: A system includes at least one variable speed generator system configured to provide power to a load bus and at least one fixed speed generator configured to provide power to the load bus. The system also includes a solid state generator (SSG) system including at least one energy storage device and a converter coupled to the at least one energy storage device and configured to transfer power between the at least one energy storage device and the load bus. The system further includes a control system configured to control the at least one variable speed generator system, the at least one fixed speed generator and the SSG system responsive to changes in a load on the load bus.

Abstract: A system includes a converter configured to be coupled between an energy storage unit and a grid and a control circuit configured to detect frequency and voltage variations of the grid and to responsively cause the converter to transfer power and reactive components to and/or from the grid. The control circuit may implement a power control loop having an inner frequency control loop and a reactive component control loop having an inner voltage control loop. The control circuit may provide feedforward from the inner frequency control loop to the inner voltage control loop to inhibit reactive component transfer in response to a voltage variation deviation of the grid due to a power transfer between the energy storage unit and the grid.

Abstract: A system includes at least one generator coupled to an island grid, at least one energy storage unit and at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid. The system further includes a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point. The at least one generator may include a control system configured to match generator output to the load and the control circuit may be configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.

Abstract: A system includes at least one generator coupled to an island grid, at least one energy storage unit and at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid. The system further includes a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point. The at least one generator may include a control system configured to match generator output to the load and the control circuit may be configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.

Abstract: A system includes at least one variable speed generator system configured to provide power to a load bus and at least one fixed speed generator configured to provide power to the load bus. The system also includes a solid state generator (SSG) system including at least one energy storage device and a converter coupled to the at least one energy storage device and configured to transfer power between the at least one energy storage device and the load bus. The system further includes a control system configured to control the at least one variable speed generator system, the at least one fixed speed generator and the SSG system responsive to changes in a load on the load bus.

Abstract: A power supply system includes an inverter circuit, for example, an inverter circuit of an uninterruptible power supply (UPS), having an output configured to be coupled to a load and an input configured to be coupled to a power source and a storage network configuration circuit configured to vary interconnections of a plurality of energy storage units of the power source, for example, plural ultracapacitors, responsive to a control input. The network configuration circuit may be operative to detect a state of the power source, such as a voltage produced thereby, and to modify parallel and serial coupling of the energy storage units responsive to the detected state. In some embodiments, the network configuration circuit may be operative to increase and/or decrease a number of the power source units connected in series across the input of the inverter circuit responsive to the detected state.

Abstract: A power supply system includes an AC input configured to be coupled to an AC source, an AC output configured to be coupled to a load, a UPS having an input coupled to the AC input and an output coupled to the AC output and a bypass circuit coupled between the AC input and the AC output and configured to open and close a bypass path therebetween. The system further includes a controller configured to control the UPS and the bypass circuit such that the UPS operates as an online UPS for a first input voltage magnitude condition at the AC input and as a standby UPS for a second input voltage magnitude condition at the AC input. A multi-mode converter may be coupled to a DC link of the UPS and configured to be selectively coupled to a battery and the AC input to respectively support battery conversion and current control at the AC input in respective first and second modes of operation of the UPS.

Abstract: A power conversion apparatus, such as a UPS, includes a first waveform reference signal generator circuit operative to generate a first waveform reference signal responsive to an AC bus, and a second waveform reference signal generator circuit operative to generate a second waveform reference signal, e.g., a more consistently sinusoidal signal produced by another source. The apparatus further includes a control circuit that selectively generates a third waveform reference signal from the first and second waveform reference signals, and a power converter circuit (e.g., a rectifier and/or inverter) coupled to the AC bus and operative to transfer power to and/or from the AC bus responsive to the third waveform reference signal. In particular, the control circuit may be operative to weightedly combine the first and second waveform reference signals to generate the third waveform reference signal.

Abstract: An AC power supply, e.g., an uninterruptible power supply (UPS), includes an output, a reference signal generator circuit operative to generate a reference signal representative of a desired voltage waveform at a node connected to the output, a power determiner circuit operative to generate an estimate of instantaneous reactive power transferred between the output and the node, and a reference signal compensator circuit responsive to the reference signal generator circuit and to the power determiner circuit and operative to generated a compensated reference signal from the reference signal responsive to the estimate of instantaneous reactive power. An AC voltage generator circuit is responsive to the reference signal compensator and operative to transfer current between the output and the node responsive to the compensated reference signal.

Abstract: An AC power supply, e.g., an uninterruptible power supply (UPS), includes an output, a reference signal generator circuit operative to generate a reference signal representative of a desired voltage waveform at a node connected to the output, a power determiner circuit operative to generate an estimate of instantaneous reactive power transferred between the output and the node, and a reference signal compensator circuit responsive to the reference signal generator circuit and to the power determiner circuit and operative to generated a compensated reference signal from the reference signal responsive to the estimate of instantaneous reactive power. An AC voltage generator circuit is responsive to the reference signal compensator and operative to transfer current between the output and the node responsive to the compensated reference signal.