Westinghouse Electric Corporation

Satcon Technology Corporation

Northrop Grumman Systems Corporation

Abb Power Td & Company

Thomas C Matty

William B Hall

Thomas C Underwood

Arun P Sahasrabudhe

James H Franz, Jr

James L Munro

Edward T Wagner

John D Strong

William E Schmitz

Larry W Anderson

Jayant K Kapadia

Robert G Colclaser, Iii

Frank J Prines

Howard N Miller

Carol D Parham

Dennis E Whalen

Pamela E DeTine

Gary O Hitchins

Aaron C James

An integrated system for comprehensive control of an electric power generation system utilizes state machine control having particularly defined control states and permitted control state transitions. In this way, accurate, dependable and safe control of the electric power generation system is provided. Several of these control states may be utilized in conjunction with a utility outage ride-through technique that compensates for a utility outage by predictably controlling the system to bring the system off-line and to bring the system back on-line when the utility returns. Furthermore, a line synchronization technique synchronizes the generated power with the power on the grid when coming back on-line. The line synchronization technique limits the rate of synchronization to permit undesired transient voltages. The line synchronization technique operates in either a stand-alone mode wherein the line frequency is synthesized or in a connected mode which sensed the grid frequency and synchronizes the generated power to this senses grid frequency. The system also includes power factor control via the line synchronization technique or via an alternative power factor control technique. The result is an integrated system providing a high degree of control for an electric power generation system.

Integrated control system and method for controlling mode, synchronization, power factor, and utility outage ride through for micropower generation systems

Integrated control system and method for controlling mode, synchronization, power factor, and utility outage ride-through for micropower generation systems

A line power unit controls electrical power delivery to a grid from a three phase permanent magnet generator. A line power unit controller receives a power level command and controls a main inverter that draws DC power from a DC bus to deliver the commanded power to a grid. The DC bus is fed DC voltage via a three phase permanent magnet generator and a rectifier. The inverter delivers power to the grid via a filter, transformer and main contactor. The line power unit controller also controls the main contactor to break the connection with the grid. A precharge circuit draws power from the grid to precharge the DC bus to a precharge voltage. Alternatives include a start inverter separate from the main inverter that permits simultaneous delivery of power to the grid and commutation of the permanent magnet generator as a motor to spin an engine connected thereto at a speed sufficient to permit engine starting. Another alternative utilizes a single inverter for engine starting and power delivery which does not permit these operations to be simultaneously performed. Further alternatives include eliminating the transformer by utilizing a high-voltage rated main inverter.

Line power unit for micropower generation

A conventional motor controlling circuit is adapted to control an inverter that drives a permanent magnet generator as a motor to spin an engine to a speed sufficient to permit the engine to start. The commutation frequency is adjusted as a function of speed utilizing an automatic commutation frequency adjustment circuit. This circuit has multiple commutation frequency ranges that overcome a large initial bearing drag during low speed operation while still permitting high speed operation. The automatic commutation frequency adjustment circuit preferably generates first and second voltage ramps that overcome the initial bearing drag and accelerate the generator at a rate fast enough for sufficient back EMF to be generated for a closed-loop commutation phase. A speedup circuit operates during the closed-loop commutation phase to achieve the high speeds typically necessary for engine starting. The inventive circuits even permit a turbine type engine to be successfully started.

Motor starting apparatus for an engine driven generator

Integrated control system and method for controlling mode,

A communications processor is disclosed for a power generation system that permits data and control signals to be communicated to and from the power generation system and a host computer. The control signals include a power level command and power factor that are sent from a remote host to the power generation system which responds by delivering the requested power level having the desired power factor to a grid. The remote host receives performance data that permits an operator to accurately gauge the performance of the power generation system including the performance and any fault conditions of a line power unit, generator, and engine driving the generator. The communications processor unburdens the line power unit controller that is responsible for controlling power generation from the task of processing input data and driving local displays. The host may also be provided at a location remote from the power generation system. The host, local or remote, preferably includes a graphical user interface that permits an operator to monitor and control the power generation system in an efficient and highly effective manner. A dedicated serial bus connects the communications processors of multiple power generation systems. By utilizing a round-robbin polling of each power generation system across the dedicated serial bus, real-time control can be achieved.

Communications processor remote host and multiple unit control devices

A method and apparatus for controlling the transmission of data, via a telephone network (20), between a first location (2,14,16) where data is collected and a central station (22). Data transmission is effected by: collecting and storing data (24-36) at the first location (2); providing an indication (42) of the current time at the first location; storing, at the first location, an indication (30) of a selected time which is after the present time and an indication (32-36) of selected ones of the plurality of data types; comparing (42) the indication of the present and selected times and establishing a connection (56), via the telephone network (20), from the first location (2,14,16) to the central station (22) when the present time becomes later than the selected time; and effecting a communication, via the connection, which includes a first transmission (56) of the selected ones of the stored data type from the first location (2,14,16) to the central station (22) and a second transmission (58 ), from the central station (22) to the first location (2,14,16), of an indication of a new selected time, and identification of the data to be collected and the locations from which that data will be obtained, for the next communication.

Automated data transmission system

TV cable apparatus wherein a stereo module unit at a user location automatically provides for the presentation of an FM audo channel associated with a particular TV channel. The FM frequency allocations associated with the particular TV channels are stored ina computer memory which may be periodically revised. The cable operator periodically sends out the latest TV channel versus FM channel frequency allocation in an FSK coded data signal which is recognized by the stereo module unit which then proceeds with an updating, if required. The data signal is sent on a normally unused FM channel and in one embodiment if this channel is changed, the apparatus is operable to find the new data channel for channel map updating.

Cable stereo apparatus

An adjustable frequency AC motor drive control system includes pulse width modulation control of an inverter coupled with the motor and a programmed microprocessor which generates a cosine wave in cooperation with a sine wave and a carrier wave to provide a synthesized sine wave voltage to the motor by controlling the conduction of power switches at a rate higher than the fundamental frequency of the sine wave voltage output.

Digital pulse width modulation motor control system

A cam controller for determining the operation of an electric motor is coupled with a stepping motor to provide predetermined positional movements of the cam controller in response to a desired electric motor operation control signal and in accordance with a programmed microprocessor determined comparison of the actual electric motor current with a requested current related to the desired operation control signal.

Propulsion control apparatus for passenger vehicles

There is disclosed a transit vehicle brake control apparatus and method which determines a safe brake velocity for the vehicle in relation to a speed control relationship including roadway system design deceleration, the deceleration of the vehicle in relation to inertial space and the deceleration of the vehicle in relation to the roadway, when the actual speed is greater than the input command speed for the vehicle from the roadway. The actual speed of the vehicle is compared with the determined safe brake velocity for the control of the vehicle speed.

Transit vehicle brake control apparatus and method

In the control of adhesion between a vehicle and a track, an adaptive control is provided for reapplying the tractive effort between the vehicle and the track in accordance with the known tractive effort level at which a loss of adhesion was sensed.

Vehicle propulsion control apparatus and method

A vehicle signal shunt detection apparatus responds to a first signal to establish the presence of a vehicle including a shunt circuit and then responds to a second signal to establish that the shunt circuit is operating to provide a desired predetermined vehicle signal.

Transit vehicle shunt determination

A signal receiving apparatus and method are provided to decode an input signal to determine the presence of at least one desired frequency component in that input signal. A number of signal samples are taken in relation to the known frequency of that signal component, and data compaction and analysis operations are performed to identify that desired frequency component. A multiple comparison made with a predetermined threshold magnitude is provided to identify the frequency component in that input signal.

Growing community of inventors

North Huntingdon, PA, United States of America

Thomas C Matty