Abstract: Techniques for detecting an island in a system including a node that is operatively coupled to a primary power source (e.g., grid) and one or more distributed power generation sources are disclosed. In one embodiment, a current pulse is included in the output of a distributed power source. The grid voltage is monitored at the node to determine if a pulse-related disturbance occurs. If the grid is present, no pulse-related disturbance will manifest. If grid is down, then a pulse-related disturbance will manifest. Detection of the pulse-related disturbance is used to signal island detection.

Abstract: The invention in the simplest form is an improved variable speed engine/generator set with an integrated power conditioning system and control method, used to generate high quality AC power with optimum fuel efficiency and reduced emissions. The variable speed generator control scheme allows for load adaptive speed control of engine and generator field. The transformerless power inverter topology and control method provides the necessary output frequency, voltage and/or current waveform regulation, harmonic distortion rejection, and provides for single phase, or unbalanced loading.

Abstract: The invention in the simplest form is an improved hybrid power converter with uninterruptible power supply (UPS) and power quality capabilities as well as an integrated variable speed power source and control method that is used to generate high quality, uninterruptible AC power utilizing fewer batteries and operating at optimum fuel efficiency and with reduced emissions. The variable speed generator control scheme allows for load adaptive speed control of a power source such as an engine and generator. The transformerless hybrid power converter topology and control method provides the necessary output frequency, voltage and/or current waveform regulation, harmonic distortion rejection, and provides for single-phase or unbalanced loading. The transformerless hybrid power converter also provides inline or offline UPS capability, line voltage and/or frequency sag and surge compensation, peak shaving capability, VAR compensation and active harmonic filtering.

Abstract: Techniques for detecting an island in a system including a node that is operatively coupled to a primary power source (e.g., grid) and one or more distributed power generation sources are disclosed. In one embodiment, a current pulse is included in the output of a distributed power source. The grid voltage is monitored at the node to determine if a pulse-related disturbance occurs. If the grid is present, no pulse-related disturbance will manifest. If grid is down, then a pulse-related disturbance will manifest. Detection of the pulse-related disturbance is used to signal island detection.

Abstract: A charging system including an alternator, and a controller for controlling the output of the alternator to provide a required output to be in tolerance with a measured load, the controller having at least one temperature sensor, and a temperature control device, wherein the temperature control device calculates the slope of temperature variance over time and, in a state of overtemperature, decreases the value provided to the controller representing the required output.

Abstract: A charging system has an alternator, a battery, and a controlled rectifier bridge between the alternator and the battery. The controlled rectifier bridge has controllable elements. A controller is provided wherein the controller controls (a) the duty cycle of the alternator field winding and (b) the switching in the controllable elements to control the phase advance angle. By utilizing a half-wave controlled rectifier bridge and three controllable elements, power output can be increased at a low overall cost. In another embodiment, the controller determines switching points for the controllable elements through a third harmonic extraction device which employs a neural network for determining the zero crossings of the third harmonic voltage obtained from a single phase voltage.