88results about How to "Power smoothing" patented technology

The present invention relates to a navigation unit and base station used for determining location. A plurality of base stations are initialized to determine their location relative to each other. At the navigation unit, the time of arrival of at least one signal from each of the plurality of base stations is measured. From this, the location of the navigation unit relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.

A hydroelectric power generating method and/or apparatus provides one or more inlet pipes perpendicular to a flow of water in a stream or river. The inlet pipes have a length and plural apertures along the length of the at least one inlet pipe. A feedline and a turbine generator combination are interconnected with the inlet pipes. One or more outlet pipes are interconnected with the feedline and the turbine generator combination. The outlet pipes have an elevation lower than the inlet pipe. A flow of water passes through the inlet pipes, the feedline, the turbine generator combination, and the outlet pipes, and generates electricity from the flow of water passing through the turbine generator combination. The hydroelectric power generating method also provides a pressure dissipation device that causes a reduction in the pressure of the water so that the water can be released safely back into the stream or river.

The present invention relates to a method of determining the location of a target. The method includes initializing a set of base stations to determine their location relative to each other. At the target, the time of arrival of at least one signal from each of the plurality of base stations Is measured. From this, the location of the target relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.

An energy buffer including an electrochemical capacitor can be added to the primary circuit and/or to the secondary circuit of in-motion wireless power transfer system. The energy buffer(s) can smoothen the power delivered by the power grid and captured by a vehicle passing over an array of transmit coils through in-motion wireless power transfer. The reduction in the transient power transfer can reduce the peak current that flows through various components of the in-motion wireless power transfer system including a vehicle battery on the vehicle, and prolong the life of the in-motion wireless power transfer system.

The invention discloses a virtual synchronous generator-based photovoltaic power control strategy, which comprises a photovoltaic power generation system, an energy storage device and an inversion device, wherein a power supply output end of the photovoltaic power generation system is respectively connected with an energy storage end of the energy storage device and an inversion end of the inversion device; the output end of the inversion device is connected with a power grid; the inversion device carries out a power control through a virtual synchronous generator method; the output power of the inversion device is adjusted through the virtual synchronous generator method to reach a stable state; the output power is adjusted according to load fluctuation; stable frequency and voltage of the photovoltaic system can be maintained; and the grid-connected generation performance of a photovoltaic power station is effectively improved.

A method for controlling a power converter in a wind turbine generator, the power converter being connected to a power grid, the method comprising obtaining an alternating current (AC) line voltage at a connection point between the power converter and the power grid, obtaining a frequency of the power grid based on the AC line voltage, dynamically adapting the AC line voltage to the frequency of the power grid, generating a reference signal based on at least the frequency-adapted AC line voltage, and determining a converter control signal to be provided to the power converter based on the reference signal and the grid frequency in order to generate a power at the frequency of the power grid. Further, a wind turbine generator implementing the method is provided.

The invention discloses a method for monitoring motor temperature. The method comprises the following steps: arranging n temperature sensors for detecting the current temperature T of a motor, wherein, n is not less than 2; reading detection data from the n temperature sensors; and obtaining the current temperature T of the motor on the basis of the detection data from the temperature sensors which normally work in the n temperature sensors. The invention further provides a method for controlling motor power. The method comprises the following steps: obtaining the current temperature T of the motor by utilizing the method for monitoring motor temperature; judging temperature range of the current temperature T of the motor according to the current temperature T of the motor and a predetermined motor temperature range threshold; and setting the maximum output power of the motor according to the temperature range of the current temperature T of the motor. By utilizing the method for monitoring the motor temperature and the method for controlling the motor power, the current temperature of the motor can be effectively and reliably obtained, and reliably and maintenance-free performance of the motor can be improved.

In a track with a rotatable bushing which is brought into engagement with a sprocket of a track-type vehicle, it is intended that strength is enhanced rationally by link functionality sharing and by combination of such assigned functional tasks for achieving further improvements in rotatable bushing function. To this end, a track link comprises a combination of an external link and an internal link; a coupler pin hole is provided through the external link; a bushing hole is provided through the internal link, and the thickness dimension of a bushing hole formation part of the internal link is made greater than that of a coupler pin formation part of the external link.

The horizontal cavity surface emitting laser includes a cavity structure portion including a stacked structure of a first conduction type clad layer, an active layer and a second conduction type clad layer stacked over a semiconductor substrate and causing light generated by the active layer to be reflected or resonated, an optical waveguide layer provided at part of the semiconductor substrate and guiding the light, a reflector provided in the optical waveguide layer, for reflecting the light and emitting the light from the back surface of the semiconductor substrate, and a condensing lens provided at the back surface thereof and focusing the reflected light. The back surface thereof has a groove provided with the condensing lens and a terrace-like portion disposed below the cavity structure portion and has a terrace shape with the cleavage direction along a longitudinal direction thereof provided along a cleavage direction of the semiconductor substrate.

A portable compound battery unit management system comprises a portable high capacity battery unit, a main power battery unit, and a DC converter. The portable high capacity battery unit has a built-in battery management means and is connected to the DC converter. The main power battery unit supplies power to a motor which in turn drives the vehicle, and contains another battery management means or a device for limiting maximum output current, or provides the DC converter and a motor controller installed behind with battery information required to operate the vehicle. The DC converter transfers the electrical energy of the portable high capacity battery unit to the main power battery unit, or converts output power of the portable high capacity battery unit to a necessary power required to operate the motor controller, wherein it has boost up or buck down function of voltage to match the voltage difference between the two battery units. With this scheme, the effectively combined portable high capacity battery unit and main power battery unit are very convenient to supply mechanical power for driving the motor bicycle to travel desired distance with a low operation and maintenance cost.

The invention discloses a control method based on a hybrid energy storage voltage source inverter (VSI) stabilizing microgrid power fluctuation. A hybrid energy storage system two-stage energy management method is designed. The method exploits the advantages, to the full, that according to a super capacitor, the power density is high, and charge and discharge cycle life is long; the super capacitor serves as system first stage energy storage stabilizing the microgrid power fluctuation preferentially; a distribution grid serves as second stage energy storage during grid connected operation; the super capacitor terminal voltage is stabilized in the range of a charging and discharging limited value by controlling the tie line power, and the PCC point bus voltage changes in an allowed range; a battery serves as second stage energy storage during island operation, the charging and discharging number of the battery is decreased through the buffering effect of the super capacitor, and the service life of the battery is prolonged; when the super capacitor reaches a charging and discharging warning value, the battery is accurately controlled to output constant power so as to adjust the super capacitor terminal voltage into a normal value. The effectiveness of the method is verified through simulation results.

An image forming device is disclosed. The device includes a toner-image forming unit which forms a toner image; a transfer unit; a fixing unit; a paper-output unit; a drive unit; a first drive-power transmission gear; a second drive-power transmission gear; a gear housing; a first positioning unit which positions the fixing unit relative to a device body; and a second positioning unit. The second positioning unit positions the paper-output unit relative to the device body in the direction of a gap between the first drive-power transmission gear and the second drive-power transmission gear by engaging the gear housing with the device body.

An energy balancing system is provided that ensures continuous energy output to compensate for energy fluctuations commonly associated with wind power generation. The flexible energy balancing system employs a base load high-pressure steam boiler that is associated with one or more steam turbine generators. The steam turbine generators are also associated with one or more heat recovery steam generators whose temperature is controlled by the exhaust from combustion turbine generators and the base load high-pressure steam boiler. The energy balancing system can be selectively tuned to quickly compensate for energy fluctuations associated with wind power generation.

The invention relates to power systems and automation, in particular to a system and a method for improving FRT (fault ride-though) capability of a DFIG-WT (doubly fed induction generator based wind turbine) on the basis of an SFCL (superconducting fault current limiter) and an SMES (superconducting magnetic energy storage). The system is characterized in the on the basis of the typical DFIG-WT, aresistor type SFCL is mounted on the stator side of the DFIG-WT, and the SMES is mounted on a direct current link of the DFIG-WT through a bidirectional DC/DC converter; the resistor type SFCL is used for limiting stator fault current of the DFIG-WT, improving generator terminal voltage sag of the DFIG-WT and absorbing partial surplus active power in the DFIG-WT; the SMES is used for stabilizingunbalanced power and electromagnetic torque oscillation. According to an FRT method for the DFIG-WT on the basis of the SFCL and the SMES, fault current can be limited under symmetrical faults and asymmetrical faults, voltage change is inhibited, and unbalanced power and electromagnetic torque oscillation are stabilized. Efficient FRT support can be provided for the DFIG-WT during FRT, and transient performance of the DFIG-WT is improved.

system and method for secure communication of collected amphibious data is disclosed, which uses direct-sequence, spread spectrum, ultra wideband (DS-SS UWB) communications to enhance the security of the collected amphibious data during transmission over a wireless communication link. The UWB technique used transmits the collected data using very short pulses with low duty cycles. Thus, the power of the transmitted signals can be distributed evenly over a large bandwidth, and buried within the environmental noise (below the noise floor) to produce “stealth” transmissions. The transmitted signals can also be encrypted, which provides a wireless data communication transmission that is immune from jamming and masked from eavesdropping attempts. As one example, a system for secure communication of collected amphibious data is disclosed, which includes a DS-SS UWB transmitter and receiver. The DS-SS UWB transmitter includes a data input unit, a data encryption unit, a UWB encoder unit, a DS spectrum spreader function unit, and a power amplifier unit. The DS-SS UWB receiver includes a receiver front end unit, a data decryption unit, a DS spectrum despreader function unit, and a receiver filter unit. As another example, the DS-SS UWB transmitter and receiver are combined to provide a DS-SS UWB transceiver.

The invention discloses a station level virtual synchronous machine control system and method and an application thereof. The station level virtual synchronous machine control system comprises power generation sources with power electronic converters as interfaces and a station level energy management system. The power generation sources access to an upper level power grid through an only common coupling point PPC; the power generation sources use the power electronic converters to realize energy conversion and access to a local grid connected point; the station level energy management system realizes power scheduling of power generation units through detecting PCC points and voltage and frequency of grid-connected interfaces of the power generation source according to a control strategy of the virtual synchronous machine. The station level virtual synchronous machine control system and method and an application thereof overcome flaws in the power electronic converter and the virtual synchronous machine, improves characteristics of primary frequency modulation and voltage regulation of the system through an inertia link of the virtual synchronous motor and can greatly improve stability of the power grid, and is applicable to distribution of high permeation and multiple access points and a big scale concentrated renewable energy power generation system.

A charging device of a robotic lawn mower includes a bottom part installed in a partial region of an operation region of the robot, a support part coupled to the bottom part and positioned on a side of a main body of the robot when the robot is being charged, and a terminal part coupled to the support part and positioned above the main body of the robot when the robot is being charged, wherein the bottom part is formed such that only any one of a plurality of wheels of the robot is mounted thereon when the robot is being charged.