Power supply systems and methods are provided. In one aspect, a power supply system includes a frame, a power input to receive input power from a power source, a power output to provide output power to a load, at least one battery module mounted in the frame and having a battery output that provides battery power, at least one power module mounted in the frame and coupled to the power input to receive the input power, coupled to the battery output to receive the battery power, and coupled to the power output to provide the output power from at least one of the battery power and the input power, a first controller coupled to the at least one power module, and a second controller, substantially similar to the first controller, coupled to the first controller, and coupled to the at least one power module, wherein each of the first controller and the second controller are configured to determine operational parameters of the power supply system and store a first set of parameters determined by the first controller and a second set of parameters determined by the second controller.

Method and apparatus for providing uninterruptible power

A current transforming harvester ("CTH") is capable of producing power from a conductor on a preexisting power grid without alteration of the conductor or the preexisting power grid. The CTH includes a current transformer ("CT") that captures energy via magnetic flux from the conductor. The CT is substantially circular and includes two halves called a "split core," which allow the CT to easily attach to the conductor without opening the circuit in which the conductor operates. A clamping mechanism of the CTH may secure the CTH to the conductor via a pair of spring-biased clamp pads. The CTH includes circuitry that converts the magnetic flux energy captured by the CT into electrical energy suitable for consumption by an electrical device.

Power line energy harvesting power supply

A power line monitoring device is mounted to a power line. The device includes circuitry for monitoring the power line and communicating information regarding the power line. A ground reference point of the circuitry is electrically coupled to the power line. Therefore, the monitoring device, including its circuitry, has substantially the same voltage potential as the power line. Accordingly, there is a substantially equalized or uniform electric field around the device The substantially equal voltage potential and electric field allow communications with the monitoring device to have reduced noise and interference, as compared to other devices that have different voltage potentials than their corresponding power lines. A pad of semi-conductive material may be disposed between the power line and the electrical conductors to slow a rate of change of the voltage potential of the device circuitry when mounting the device to the power line, minimizing risk of corona discharge.

Overhead communicating device

A variable speed wind turbine employing a rotor (103) connected to a multiplicity of synchronous generators (106 - 112) with wound field or permanent magnet rotors. A passive rectifier (114 - 120) and an inverter (136 - 142) are used for power transfer back to the grid. A Turbine Control Unit (TCU) (132) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system (102). A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

Variable speed distributed drive train wind turbine system

To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.

Wind Turbine Generator System

A power controller controls the turbine of a turbine powered generating system regardless of the load on the system to maximize the efficiency of the turbine and maintains the turbine at a substantially constant temperature during a system load change by using an energy storage device to provide power to the load while the turbine is changing speed to meet the new load demand.

Method and system for control of turbogenerator power and temperature

A method of controlling a generator system connected to an electric power system in which the output frequency characteristic of the generator system is measured, a first phase angle and frequency of the measured frequency characteristic is estimated using a first phase locked loop having a first bandwidth, and a second phase angle and frequency of the measured frequency characteristic is estimated using a second phase locked loop having a second bandwidth greater than the first bandwidth. Further, the method calculates a frequency difference between the first and second estimated frequencies, and an angle variation that is proportional to the calculated frequency difference. The estimated second phase angle is then added to the calculated angle variation so as to form an output current phase angle reference, and an output current phase angle of the generator system is controlled to be aligned with the output current phase angle reference. The method also determines whether or not the generator system is within a generation island based on the measured frequency characteristic.

Detection of islanded behavior and anti-islanding protection of a generator in grid-connected mode

In an integrated turbogenerator system having an air intake for a compressor to supply combustion air to a combustor, an electric brake device such as a resistor is connected to the electrical power output of the turbogenerator and is situated in the air intake to be cooled by the stream of combustion air flowing into the intake. When load transients require unloading excess electrical power produced by the turbogenerator, the brake resistor is supplied with at least part of the excess electrical power to create heat energy and thereby heat the in-flowing combustion air to lower the combustor efficiency, turbogenerator power produced, and excess electric power to be unloaded. An algorithm may be provided for controlling the turbogenerator speed deceleration rate to maintain the brake resistor at or near a physical temperature limit.

Turbogenerator with electrical brake

A continuous power supply may include a turbogenerator to provide power to supply the load and or an energy storage element and possibly also to the primary energy source. Utilizing an isolated DC bus architecture permits bi-directional power flow among interconnected elements.

Continuous power supply with back-up generation

A turbogenerator system including a recuperator and a catalytic combustor employs a preheater located between the turbine outlet and the recuperator low-pressure inlet to heat the low-pressure turbine exhaust. Heat from the turbine exhaust is transferred to a cool high-pressure flow in the recuperator. A recirculation loop employs valves downstream of the recuperator low-pressure outlet to divert the recuperator low-pressure exhaust into the compressor to be recirculated through the recuperator high-pressure side and the catalytic combustor. Reduced start-up times and emissions are achieved by raising the combustor catalyst to its light-off temperature in a shorter period of time.

Simon R. Wall

Papers

Method and system for control of turbogenerator power and temperature

Detection of islanded behavior and anti-islanding protection of a generator in grid-connected mode

Turbogenerator with electrical brake

Continuous power supply with back-up generation

Method and apparatus for indirect catalytic combustor preheating