Patent application number | Description | Published |
20100090537 | COMPENSATION SYSTEM FOR POWER TRANSMISSION - A system is provided for compensating a power transmission line having one or more non-conventional power generating sources connected to the power transmission line. At least one series compensation circuit is connected to a portion the power transmission line, and at least one damping circuit is connected in parallel with the series compensation circuit. The damping circuit reduces subsynchronous series resonance caused by the series compensation circuit on the power transmission line, and the series compensation circuit compensates the power transmission line. | 04-15-2010 |
20100090538 | COMPENSATION SYSTEM FOR POWER TRANSMISSION - A system for compensating a power transmission grid is provided. The system includes one or more non-conventional power generating sources that are connected to the power transmission grid. At least one series compensation circuit is connected to at least a portion of the power transmission grid, to compensate the power transmission grid. At least one damping circuit is connected to at least a portion of the power transmission grid, and it mitigates subsynchronous series resonance caused by the series compensation circuit on the power transmission grid. | 04-15-2010 |
20100094474 | VOLTAGE CONTROL AT WINDFARMS - A voltage control arrangement for a system of multiple windfarms with transmission lines. Voltage is regulated at a point of regulation on the system, such as a high voltage substation or other system bus. Regulation is achieved at the point of regulation by sensing the voltage, comparing to a reference voltage, and adjusting the reactive power output of the wind turbines and other equipment in the system. The regulation point may be shifted to another point if needed to respect voltage limits at that points of the system after attempting to shift reactive load to restore voltage within limits at the other points in the system. The reference voltage may be adjusted to minimize losses for the system of multiple windfarms and transmission lines. A loss optimizing algorithm is applied to the combined multiple windfarm and transmission line to shift reactive load among local windfarms to minimize losses and to shift reactive load among individual wind turbines within an individual windfarm. | 04-15-2010 |
20120010756 | VOLTAGE CONTROL AT WINDFARMS - A voltage control arrangement for a system of multiple windfarms with transmission lines. Voltage is regulated at a point of regulation on the system, such as a high voltage substation or other system bus. Regulation is achieved at the point of regulation by sensing the voltage, comparing to a reference voltage, and adjusting the reactive power output of the wind turbines and other equipment in the system. The regulation point may be shifted to another point if needed to respect voltage limits at that points of the system after attempting to shift reactive load to restore voltage within limits at the other points in the system. The reference voltage may be adjusted to minimize losses for the system of multiple windfarms and transmission lines. A loss optimizing algorithm is applied to the combined multiple windfarm and transmission line to shift reactive load among local windfarms to minimize losses and to shift reactive load among individual wind turbines within an individual windfarm. | 01-12-2012 |
Patent application number | Description | Published |
20090250943 | SYSTEMS AND METHODS INVOLVING OPERATING VARIABLE SPEED GENERATORS - A method for operating an asynchronous generator comprising receiving an indication that a power grid frequency is reduced. Responsive to the receiving the indication, reducing a speed of the asynchronous generator from a first speed to a second speed for a first time period, wherein the reduction of the speed of the asynchronous generator results in a momentary increase in a total power output of the asynchronous generator. Increasing the speed of the asynchronous generator from the second speed to a third speed responsive to the end of the first time period. | 10-08-2009 |
20090251109 | SYSTEMS AND METHODS INVOLVING STARTING VARIABLE SPEED GENERATORS - An exemplary method for starting a generator, the method comprising, starting a rotor with an AC voltage across the rotor. Starting a stator. Increasing a speed of the rotor. | 10-08-2009 |
20100141193 | TORSIONAL MODE DAMPING APPARATUS - A torsional-mode damping system includes a torque sensor, a torsional damper connected to the torque sensor, a VFD controller connected to the torsional damper, and a VFD converter connected to the VFD controller, the VFD converter being configured to control an electric power supplied to the electric motor based on VFD signals generated by the VFD controller, the VFD signals being modified by a torque-correcting signal so as to dampen torsional vibrations at a natural frequency of a compression train. | 06-10-2010 |
20100332045 | Regulation of Generating Plant - A method and system are disclosed that enable the regulation of the temperature of transmission equipment connected to a generating plant. In one embodiment, a method includes obtaining a temperature of transmission equipment connected to a generating plant and regulating the output of the generating plant in response to the temperature exceeding a threshold level to reduce the temperature of the transmission equipment to below the threshold level. | 12-30-2010 |
20110141641 | CIRCUIT BREAKER WITH OVERVOLTAGE PROTECTION - A circuit breaker is provided for protecting dynamoelectric machinery. The circuit breaker includes a feeder input connection connected to a feeder line. The feeder line is connected to a dynamoelectric machine. A substation connection is connected to a substation bus. An interrupting breaker is connected between the feeder input connection and the substation connection. A shorting switch is connected to the feeder input connection, and an impedance device is connected to the shorting switch and a ground or neutral. The impedance device, shorting switch and ground/neutral reduces excessive voltages on the feeder line when the feeder line is isolated from the substation by the circuit breaker, and the impedance device is selected to reduce a torque transient experienced by the dynamoelectric machine. | 06-16-2011 |
20120243129 | SHORTING PROTECTION FOR SYSTEMS HAVING ELECTRIC MACHINES - Shorting protection for systems having electric machines is provided. A protective device is put in shunt with an electric power system and an electric machine. The protective device is in an open state during normal operation and in a closed state in response to detection of a fault. In the closed state, the protective device forms a short circuit that isolates the electric power system from the electric machine. | 09-27-2012 |
20130079945 | METHOD AND SYSTEM FOR OPERATING A POWER GENERATION AND DELIVERY SYSTEM - A method for controlling operation of a power generation and delivery system while increasing a power output of the power generation and delivery system is described. The method includes, monitoring an output parameter of the power generation and delivery system and determining a rate of change of the output parameter as a function of time. A reactive current command signal is generated a as a function of the determined rate of change of the output parameter. Operation of a power converter is controlled based at least partially on the reactive current command signal to facilitate maintaining a substantially constant terminal voltage as the power output of the power generation and delivery system is increased. | 03-28-2013 |
20130270916 | SYSTEMS AND METHODS FOR LIMITING VOLTAGE ON AN AUXILIARY BUS - Systems and methods for limiting voltage on an auxiliary bus are described. The voltage-limited auxiliary bus may be comprised of a DC auxiliary bus comprised of a positive conductor and a negative conductor; a chopper, wherein the chopper is normally in a non-conducting state; a resistor in series with the chopper, wherein the chopper and the resistor are connected between the positive conductor and the negative conductor of the DC auxiliary bus; and a chopper control, wherein an overvoltage on the DC auxiliary bus causes the chopper control to cause the chopper to begin conducting and the conducting limits the voltage on the DC auxiliary bus and dissipates energy from the overvoltage. | 10-17-2013 |
20140043080 | METHODS AND SYSTEMS FOR CONTROLLING A POWER CONVERTER - A line angle shift logic controller for use with a power generation system coupled to an electrical grid is disclosed. The line angle shift controller includes a line angle shift controller configured to receive a phase locked loop (PLL) error signal representative of a difference between a phase angle of the power generation system and a phase angle of the electrical grid, receive a threshold phase from the electrical grid, and generate a PLL shift signal based at least partially on the PLL error signal and the threshold phase. | 02-13-2014 |
20140062424 | SYSTEM AND METHOD FOR CONTROLLING A DUAL-FED INDUCTION GENERATOR IN RESPONSE TO HIGH-VOLTAGE GRID EVENTS - In one aspect, a method for controlling a dual-fed induction generator (DFIG) during a high-voltage grid event is provided. The method includes setting, by a controller, an output of a closed-loop portion of a rotor current regulator to a fixed value such that a predictive feed-forward path sets an internal voltage for the DFIG; and detecting, by the controller, a condition of high dc voltage on a dc link or a condition predictive of high dc voltage on the dc link, and in response reduce a rotor torque producing current command to approximately zero, wherein the dc link connects a line-side converter connected to a system bus and a rotor-side converter connected to a rotor of the DFIG. | 03-06-2014 |
20140070535 | METHOD AND SYSTEMS FOR OPERATING A WIND TURBINE USING DYNAMIC BRAKING IN RESPONSE TO A GRID EVENT - A method and system for dissipating energy in a direct current (dc) bus of a doubly-fed induction generator (DFIG) converter during a grid event is described. In one aspect, the method comprises monitoring operating conditions of an electrical system, the electrical system comprising at least a DFIG generator and a line side converter and a rotor side converter connected by a dc bus having a dynamic brake connected thereto; detecting an overvoltage on the dc bus or a condition indicative of an overvoltage on the dc link is detected, the overvoltage on the dc bus or condition indicative of the overvoltage caused by a grid event; and causing energy in the dc link to be dissipated using the dynamic brake. | 03-13-2014 |
20140152010 | METHOD AND SYSTEMS FOR OPERATING A WIND TURBINE WHEN RECOVERING FROM A GRID CONTINGENCY EVENT - A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes receiving, by a controller, a power command signal, wherein the power command signal indicates recovery from the grid contingency event; and increasing, in a non-uniform manner, power injected into a grid by a power conversion assembly in response to the power command signal wherein the controller controls the power conversion assembly. | 06-05-2014 |
20150249412 | SYSTEM AND METHOD FOR CONTROLLING A POWER GENERATION SYSTEM BASED ON PLL ERRORS - In one aspect, a method for controlling a power generation system may generally include determining a phase angle error associated with the power generation system, determining a scaling factor based on the phase angle error, generating a current command for controlling the operation of a power convertor of the power generation system and applying the scaling factor to the current command such that the current command is reduced when the phase angle error exceeds a predetermined error threshold. | 09-03-2015 |
20150249413 | SYSTEM AND METHOD FOR ADJUSTING CURRENT REGULATOR GAINS APPLIED WITHIN A POWER GENERATION SYSTEM - In one aspect, a method for controlling the operation of a power generation system configured to supply power to an electrical grid may generally include monitoring a rotor speed of a generator of the power generation system and determining a gain scaling factor based on the rotor speed, wherein the gain scaling factor increases with decreases in the rotor speed across a range of rotor speeds. In addition, the method may include adjusting a regulator gain to be applied within a current regulator of the power generation system based on the gain scaling factor and applying the adjusted regulator gain within the current regulator in order to generate a voltage command signal for controlling a power converter of the power generation system. | 09-03-2015 |
Patent application number | Description | Published |
20100123356 | RESONANCE MITIGATION SYSTEM AND METHOD - A system for reducing resonance from harmonic distortion in a high voltage power system is presented. The system includes a voltage damper coupled to the high voltage power system between a cable sheath and an earth connection. The voltage damper is configured to clamp voltage peaks. The system also includes a frequency shifter coupled across the voltage damper and configured to displace a resonance frequency of the high voltage power system. | 05-20-2010 |
20110101689 | METHOD AND APPARATUS FOR GENERATING POWER IN A WIND TURBINE - A power converter for a wind turbine including an array of switching devices and a control module having a current damping device. The control module is configured to control a switching behavior of the array of switching devices and to receive a current having a first frequency component from the wind turbine. The current damping device is configured to reduce an amplitude of the first frequency component. | 05-05-2011 |
20110137474 | METHOD AND SYSTEMS FOR OPERATING A WIND TURBINE - A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes measuring at least one operating condition of the power generation and delivery system. The method also includes transmitting, to a power limiter system, an operating condition feedback signal that corresponds to the operating condition. The method also includes analyzing the operating condition feedback signal to identify an occurrence of a grid contingency event and generating a real current command signal corresponding to an occurrence of a grid contingency event. The method also includes transmitting the real current command signal to a controller and applying the real current command signal to power converter performance to facilitate reducing pole-slipping. The method also includes storing, in a memory, at least one variable corresponding to the operating condition upon the occurrence of a grid contingency event. | 06-09-2011 |
20110140511 | ELECTRIC POWER TRANSMISSION SYSTEM FOR WIND TURBINE AND WIND TURBINE FARM AND METHOD FOR OPERATING SAME - A method of operating a wind turbine includes energizing at least a portion of a power conversion assembly via an alternating current (AC) power source. The method also includes converting AC power to direct current (DC) power having a DC component and an AC component via the power conversion assembly. The method further includes transmitting the DC component and the AC component through a DC power transmission line. The method also includes separating the DC component from the AC component. The method further includes transmitting the AC component to at least one wind turbine electrical device. | 06-16-2011 |
20110141773 | HVDC CONNECTION OF WIND TURBINE - A method and apparatus for connection of a wind driven turbine generator to an HVDC transmission line is provided that does not require transformation of the wind generated AC voltage to a nominal AC distribution grid frequency. An AC output from the turbine generator is increased in level and converted to HVDC for direct application to a HVDC transmission line. The wind turbine generated AC may be first increased in frequency via a matrix converter and then rectified or may be first rectified and increased in level by a high-voltage DC-DC converter circuit and then applied directly to the HVDC transmission line. | 06-16-2011 |
20110221280 | SYSTEM AND METHOD FOR CONTROL OF A GRID CONNECTED POWER GENERATING SYSTEM - A power generating system includes an energy source coupled to a DC link through a first power converter and a second power converter to couple the DC link to a power grid. A first controller in the power generating system regulates voltage on the DC link and a second controller regulates a parameter of the energy source. A dynamic parsing controller coupled to the first power converter and the second power converter selectively parses the output signals of the first and second controllers and generates operating commands for the first and second power converters based at least in part on the parsed output signals. | 09-15-2011 |
20120010759 | METHOD AND SYSTEMS FOR OPERATING A WIND TURBINE - A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes measuring at least one operating condition of the power generation and delivery system. The method also includes transmitting, to a power limiter system, an operating condition feedback signal that corresponds to the operating condition. The method also includes analyzing the operating condition feedback signal to identify an occurrence of a grid contingency event and generating a real current command signal corresponding to an occurrence of a grid contingency event. The method also includes transmitting the real current command signal to a controller and applying the real current command signal to power converter performance to facilitate reducing pole-slipping. The method also includes storing, in a memory, at least one variable corresponding to the operating condition upon the occurrence of a grid contingency event. | 01-12-2012 |
20130148393 | METHODS AND SYSTEMS FOR CONTROLLING A POWER CONVERTER - A controller for controlling a power converter is described. The controller includes an input configured to receive at least one grid feedback signal, a filter, and an output. The filter is configured to receive the at least one grid feedback signal and generate an output signal that does not deviate by more than a predefined amount from the at least one grid feedback signal. The output is configured to provide a voltage command signal to the power converter that is based at least partially on the output signal. | 06-13-2013 |
20130278308 | METHODS AND SYSTEMS FOR CONTROLLING A POWER CONVERTER - A stabilizer system associated with a power converter controller is described. The stabilizer system includes a regulator stabilizer configured to receive a phase locked loop (PLL) error signal and to generate a regulator stabilization signal based at least partially on the PLL error signal. The stabilizer system also includes a regulator coupled to the regulator stabilizer and a converter interface controller. The regulator is configured to receive the regulator stabilization signal, generate a first command signal, based at least partially on the regulator stabilization signal, that reduces system oscillations, and transmit the first command signal to the converter interface controller. | 10-24-2013 |
20140062085 | VOLTAGE CONTROL FOR WIND TURBINE GENERATORS - A voltage control system for a wind turbine generator may include a reactive power regulator configured to control reactive power production by the wind turbine generator by adjusting a voltage setpoint for the generator. The reactive power regulator may have a first time constant and the voltage setpoint may be defined between an upper limit and a lower limit. The system may also include a voltage limit regulator configured to adjust at least one of the upper limit or the lower limit for the voltage setpoint based on a voltage-related parameter. In addition, the system may include a voltage regulator coupled to the reactive power regulator. The voltage regulator may be configured to control real power production by the wind turbine generator based on the voltage setpoint. The voltage regulator may have a second time constant, wherein the first time constant is numerically greater than the second time constant. | 03-06-2014 |
20150061289 | SYSTEM AND METHOD FOR VOLTAGE CONTROL OF WIND GENERATORS - A method for reactive power generation for a wind turbine generator includes receiving a voltage command signal, and adjusting this voltage command signal as a function of the wind turbine reactive power. A reactive current is determined for the wind turbine generator in response to the adjusted voltage command signal and is transmitted to a controller of the wind turbine generator for generating a real and reactive power based on the reactive current command. | 03-05-2015 |
20150061290 | SYSTEM AND METHOD FOR VOLTAGE CONTROL OF WIND GENERATORS - A system and associated method for reactive power generation for a wind turbine generator includes receiving a higher-than-generator level voltage command signal. A reactive current is determined for the wind turbine generator in response to the voltage command signal and is transmitted to a controller of the wind turbine generator for generating a real and reactive power based on the reactive current command. A trim value may be generated and applied to the voltage command signal. | 03-05-2015 |
20150256094 | HYBRID HIGH VOLTAGE DIRECT CURRENT CONVERTER SYSTEM AND METHOD OF OPERATING THE SAME - A hybrid HVDC converter system includes a DC bus, at least one capacitor commutated converter (CCC) and at least one self-commutated converter (SCC) coupled in series through the DC bus. The CCC induces a first voltage on the DC buses, the SCC induces a second voltage on the DC bus, the first voltage and the second voltage are summed to define a total DC voltage. The method includes at least one of regulating the total DC voltage induced on the DC buses including regulating the first DC voltage through the CCC and regulating the second DC voltage through the SCC substantially simultaneously, regulating the total DC voltage induced on the DC bus including regulating the second DC voltage through the SCC, and regulating the total DC voltage induced on the DC bus including regulating the first DC voltage through the CCC. | 09-10-2015 |
Patent application number | Description | Published |
20100135935 | Composition using cross-linked hyaluronic acid for topical cosmetic and therapeutic applications - Disclosed are compositions comprising crosslinked hyaluronic acid gels, preferably vinyl sulfone cross-linked hyaluronic acid known as hylan B gel, for use in topical cosmetic and dermatological formulations. The hylan B gel in these formulations provides prolonged delivery of incorporated substances to the surface of the skin, to provide a hydrated film on the surface of the skin, and to provide a substantive and compatible film on the skin. | 06-03-2010 |
20110076243 | Modified hydrophilic polymers containing hydrophobic groups - Disclosed are hydrophilic polymers such as polysaccharides, including hyaluronic acid of any origin, modified by reaction with epoxy-functional-silicones. Hydrophobic silicon, which contains chemically active groups covalently attach to the backbone of the hydrophilic polymer and gives these new, modified polymers the ability to dissolve hydrophobic compounds including oils, drugs, and vitamins, while maintaining the hydrophilic properties and benefits of the unmodified polymer. With respect to topical applications these polymers substantially increase the stability of formulations and provide for ease of preparation. The properties and advantages of the original polymer are maintained while other properties are augmented, namely the ability to combine with or dissolve hydrophobic and hydrophilic drugs. The products can be used alone or in combination with other substances for various applications including cosmetic, medical, and drug delivery applications. Also disclosed are methods for preparing them. | 03-31-2011 |
20140286884 | COMPOSITION USING CROSS-LINKED HYALURONIC ACID FOR TOPICAL COSMETIC AND THERAPEUTIC APPLICATIONS - Disclosed are compositions comprising crosslinked hyaluronic acid gels, preferably vinyl sulfone cross-linked hyaluronic acid known as hylan B gel, for use in topical cosmetic and dermatological formulations. The hylan B gel in these formulations provides prolonged delivery of incorporated substances to the surface of the skin, to provide a hydrated film on the surface of the skin, and to provide a substantive and compatible film on the skin. | 09-25-2014 |
20150132237 | COMPOSITION USING CROSS-LINKED HYALURONIC ACID FOR TOPICAL COSMETIC AND THERAPEUTIC APPLICATIONS - Disclosed are compositions comprising crosslinked hyaluronic acid gels, preferably vinyl sulfone cross-linked hyaluronic acid known as hylan B gel, for use in topical cosmetic and dermatological formulations. The hylan B gel in these formulations provides prolonged delivery of incorporated substances to the surface of the skin, to provide a hydrated film on the surface of the skin, and to provide a substantive and compatible film on the skin. | 05-14-2015 |
20150132238 | COMPOSITION USING CROSS-LINKED HYALURONIC ACID FOR TOPICAL COSMETIC AND THERAPEUTIC APPLICATIONS - Disclosed are compositions comprising crosslinked hyaluronic acid gels, preferably vinyl sulfone cross-linked hyaluronic acid known as hylan B gel, for use in topical cosmetic and dermatological formulations. The hylan B gel in these formulations provides prolonged delivery of incorporated substances to the surface of the skin, to provide a hydrated film on the surface of the skin, and to provide a substantive and compatible film on the skin. | 05-14-2015 |