7372 results about "Variable-frequency drive" patented technology

An apparatus and method of wirelessly sharing power by an inductive method are provided. The apparatus includes a first battery supplying power; a rectifier supplied with an AC voltage, converts the AC voltage into a DC voltage, and outputs the DC voltage; an inverter supplied with the DC voltage, converts the DC voltage into the AC voltage, and outputs the AC voltage; a power control / conversion unit connected to the rectifier or the inverter and supplying power to charge the first battery or a second battery that is provided in an external device as a power supply for the first battery; and a communication unit communicating with the external device.

A system and method are disclosed for centralized monitoring and control of a hydraulic fracturing operation. The system includes an electric powered fracturing fleet and a centralized control unit coupled to the electric powered fracturing fleet. The electric powered fracturing fleet can include a combination of one or more of: electric powered pumps, turbine generators, blenders, sand silos, chemical storage units, conveyor belts, manifold trailers, hydration units, variable frequency drives, switchgear, transformers, and compressors. The centralized control unit can be configured to monitor and / or control one or more operating characteristics of the electric powered fracturing fleet.

A system and method are disclosed for centralized monitoring and control of a hydraulic fracturing operation. The system includes an electric powered fracturing fleet and a centralized control unit coupled to the electric powered fracturing fleet. The electric powered fracturing fleet can include a combination of one or more of: electric powered pumps, turbine generators, blenders, sand silos, chemical storage units, conveyor belts, manifold trailers, hydration units, variable frequency drives, switchgear, transformers, and compressors. The centralized control unit can be configured to monitor and / or control one or more operating characteristics of the electric powered fracturing fleet.

A system for stimulating oil or gas production from a wellbore includes a hydraulic fracturing pump unit having one or more hydraulic fracturing pumps driven by one or more electrical fracturing motors, a variable frequency drive (VFD) controlling the electrical fracturing motors, a fracturing pump blower unit driven by a blower motor, and a fracturing pump lubrication unit having a lubrication pump driven by a lubrication motor and a cooling fan driven by a cooling motor. The system may further include a blender unit and a hydration unit. A system control unit may control the operational parameters of the system.

A pumping system for use in hydraulic fracturing or fracing of wells. The pumping system is generally self-contained on a transportable system, such as a trailer. The weight and configuration of the trailer must be sized to be hauled legally on United States roadways. The system components include a diesel generator with cooling radiator, a variable-frequency drive (VFD) with cooling system, an A / C induction motor and a high capacity pump. The system may also include a second generator to power other items, such as cooling fans, cooling pumps, lube pumps, lighting and electrical outlets and air conditioning units for cooling equipment. In some embodiments, the system includes single components, while other embodiments include redundant components.

Methods and systems for producing a change in a medium. A first method and system (1) place in a vicinity of the medium at least one upconverter including a gas for plasma ignition, with the upconverter being configured, upon exposure to initiation energy, to generate light for emission into the medium, and (2) apply the initiation energy from an energy source including the first wavelength λ1 to the medium, wherein the emitted light directly or indirectly produces the change in the medium. A second method and system (1) place in a vicinity of the medium an agent receptive to microwave radiation or radiofrequency radiation, and (2) apply as an initiation energy the microwave radiation or radiofrequency radiation by which the agent directly or indirectly generates emitted light in the infrared, visible, or ultraviolet range to produce at least one of physical and biological changes in the medium.

An apparatus configured to hydraulically fracture an earth formation, includes a pump configured to hydraulically fracture the earth formation by pumping a fracturing liquid into a borehole penetrating the earth formation and an electric motor having a rotor coupled to the pump and a stator. A motor control center is configured to apply an alternating electrical voltage having a fixed-frequency to the stator in order to power the electric motor, wherein the apparatus and motor control center do not have a variable frequency drive.

A system for stimulating oil or gas production from a wellbore includes a hydraulic fracturing pump unit having one or more hydraulic fracturing pumps driven by one or more electrical fracturing motors, a variable frequency drive (VFD) controlling the electrical fracturing motors, a fracturing pump blower unit driven by a blower motor, and a fracturing pump lubrication unit having a lubrication pump driven by a lubrication motor and a cooling fan driven by a cooling motor. The system may further include a blender unit and a hydration unit. A system control unit may control the operational parameters of the system.

The invention is directed to controlling an electric motor by means of a frequency converter. The frequency converter can be connected to one of several different mains voltages. According to the present invention, the maximum output power of the frequency converter, is limited when the actual mains voltage is lower than the maximum nominal mains voltage, for which the frequency converter is designed, and during the limitation the frequency converter controls the speed of the motor within a power range up to a limited maximum output power. This gives a genuine multi-voltage unit, which can be connected to a wide range of mains voltages.

A system for fracturing a subsurface formation may comprise a transport unit with hydraulic legs, an electric motor mounted on the transport unit, a fracking pump mounted on the transport unit and configured to be powered by the electric motor, and an oil tank mounted on the transport unit such that the motor and the fracking pump are above the oil tank. The oil tank may have a first tank height under the pump and a second tank height under the motor and the first tank height may be greater than the second tank height. The oil tank, motor support beam, and pump support beam may form a single structural unit. The system may also include an oil pump for pumping lubricating oil through the fracking pump, an electric motor configured to drive the oil pump, a variable frequency drive configured to control the electric motor.

An electric driven hydraulic fracking system is disclosed. A pump configuration that includes the single VFD, the single shaft electric motor, and the single hydraulic pump that is mounted on the single pump trailer. A pump configuration includes a single VFD configuration, the single shaft electric motor, and the single shaft hydraulic pump mounted on the single pump trailer. The single VFD configuration converts the electric power at the power generation voltage level distributed from the power distribution trailer to a VFD voltage level and drives the single shaft electric motor to control the operation of the single shaft electric motor and the single hydraulic pump. The VFD voltage level is a voltage level that is required to drive the single shaft electric motor. The VFD configuration also controls operation of the auxiliary systems based on the electric power at the auxiliary voltage level.

The present invention provides a generalized frequency conversion system for a steam turbine generator unit. The system comprises at least a steam turbine (T) with an adjustable rotating speed, a water feeding pump (BFP), a generator (G), a speed increasing gearbox (GB), a variable frequency bus (a, c) and an auxiliary machine connected thereto. With a change in load of the unit, parameters of steam entering the steam turbine (T) and an extracted steam amount are correspondingly adjusted (changed), so that the rotating speed of the steam turbine (T) changes correspondingly; and thus the rotating speed of the water feeding pump (BFP) is changed through the speed increasing gearbox (GB) on the one hand, and the frequency of an alternating current outputted by the generator (G) is changed on the other hand. Other types of frequency converters do not need to be additionally provided. The system is simple, reliable, low in cost, and high in efficiency.

Radio system including mixer device and switching circuit and method having switching signal feedback control for enhanced dynamic range and performance. Radio apparatus including: local oscillator input port for receiving periodic sinusoidal local oscillator signal; drive circuit for generating a substantially square-wave two-voltage level switching signal including: phase splitter circuit, voltage potential isolation circuit, and square wave signal generation circuit; FET mixing device; input / output signal separation circuit; analog-to-digital converter; and feedback control circuit. Radio tuner apparatus including low-band signal processing circuit; high-band signal processing circuit including first mixer circuit operating as an up-frequency converter, amplifier circuit, second mixer circuit operating as a down-frequency converter, and feedback control circuit for adjusting a duty cycle of a mixer switching device; signal combining circuit and output processing circuit. Method for operating radio system, apparatus, and tuner. Method of operating switching circuit.

A well service pump system supplies high pressure working fluid to a well. The pump system is a linear design which incorporates an electric motor, a variable frequency drive (VFD), a pump drive, closed loop variable flow rate hydraulic pumps, hydraulic ram cylinders, working fluid end cylinders, and a coupling to connect the hydraulic ram cylinders and the working fluid end cylinders. The electric motor powers the hydraulic system which, in turn, provides hydraulic fluid to operate the hydraulic ram cylinders. The VFD is connected to a single one of the hydraulic pumps at a time and applies power to the connected pump, via the pump drive, to drive the connected pump from a cold start to an operating speed. The VFD is connected sequentially, one pump at a time, to each of the hydraulic pumps and disconnected from each pump once the pump reaches the operating speed. Once the pump reaches operating speed, the pump is connected to receive power directly to the electric motor.

The invention discloses an electric drive fracturing semi-trailer of a frequency conversion integrated machine. The optimization and integration of the traditional power supply semi-trailer and the fracturing semi-trailer realize the functions of power supply and fracturing of one semi-trailer without using the complete set of the power supply semi-trailer and the fracturing semi-trailer, the electric drive fracturing semi-trailer is more flexible in actual use, and the well field layout of oil and gas fields is greatly optimized; the transportation is convenient; only a set of high-voltage cables can be connected with the high-voltage power supply to reach a working state, and the wiring installation is faster; compared with diesel-driven fracturing, and the noise of the electric drive fracturing is low without exhaust emission pollution; the driving source is power, which has lower cost than the diesel; the electric drive fracturing semi-trailer adopts an integrated design of a motorand a frequency converter (namely, the frequency conversion integrated machine), the space occupied by the electric motor and the inverter in the prior art is reduced effectively, so the installing part of the electric drive fracturing semi-trailer has smaller volume and the transportation is more convenient, and can also provide space guarantee for installing other equipment on the semi-trailerbody.

An electric driven hydraulic fracking system is disclosed. A pump configuration that includes the single VFD, the single shaft electric motor, and the single hydraulic pump that is mounted on the single pump trailer. A pump configuration includes a single VFD configuration, the single shaft electric motor, and the single shaft hydraulic pump mounted on the single pump trailer. The single VFD configuration converts the electric power at the power generation voltage level distributed from the power distribution trailer to a VFD voltage level and drives the single shaft electric motor to control the operation of the single shaft electric motor and the single hydraulic pump. The VFD voltage level is a voltage level that is required to drive the single shaft electric motor. The VFD configuration also controls operation of the auxiliary systems based on the electric power at the auxiliary voltage level.

Agile frequency converter and method, IF-RF level exchange process, and notch filtering techniques. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. Converter employs two-stage frequency conversion process, with gain exchange system using variable pre-mixer gain and variable post-mixer attenuation to maintain constant RF output signal power level. For those few conversion frequencies where distortion component(s) cannot be filtered without degrading desired signal, IF-RF level exchange is optimized for meeting the carrier-to-distortion (C / D) ratio specifications at slight expense of noise level for that channel only, while still meeting aggregate combined carrier-to-noise (C / N) specification requirements. Optimal apportionment of level exchange for each channel depends on specific frequency rejection capability of spurious components and is matched to filtering capability and stored within non-volatile memory of a microcontroller used in the frequency converter.

A method is provided including installing a variable frequency drive unit to drive a previously non-variable air handler fan of an HVAC system. The method includes setting a control strategy for the variable frequency drive. The control strategy includes a drive speed for each mode of the HVAC system. The method includes operating the HVAC system in each mode and monitoring the HVAC system. The method includes adjusting the HVAC system or the control strategy of the variable frequency drive to increase drive speed based on monitoring the HVAC system.

The invention discloses a frequency-change radar goal emulator of millimeter wave, which comprises the following parts: control unit, transceiver unit, Doppler analog unit, distant analog unit and amplitude analog unit, wherein the radar signal enters into the Doppler analog unit through transceiver unit, which produces middle-frequency signal through lower frequency-changer and low-pass filter of the Doppler analog unit; the upper frequency-changer and band-pass filter group of Doppler analog unit produces RF signal; the difference of local oscillator frequency of upper and lower frequency-changers analogs the Doppler frequency shift of goal; the RF signal generates launching signal through changing the echo amplitude of goal simulated by amplitude analog unit, which is transmitted by transceiver unit; the control unit transmits control signal for other four units according to the analog parameter such as input distance, speed and amplitude; the radar signal passes the emulator to provide an analog signal with Doppler frequency shift, signal amplitude fluctuation and distant delay to radar, which provides estimating platform for working property testing for radar.

The invention relates to a method for intelligently controlling the frequency of a variable-frequency air-conditioner, comprising the following steps of: (1) reading the temperature difference delta T of the set temperature of the variable-frequency air-conditioner and indoor ambient temperature and calculating a frequency value Ft according to the temperature difference by a frequency converter;(2) reading each running parameter of the variable-frequency air-conditioner and controlling the air-conditioner to stop, or limit the frequency, or reduce the frequency or normally run according to the parameter value by using the frequency converter; (3) if each parameter displays that the frequency needs to be limited, ensuring the adjusted frequency Fobj to be equal to Ft, and if each parameter displays that the frequency needs to be reduced, ensuring the Fobj to be equal to Ft-delta T; (4) if each parameter displays the normal running, adjusting the frequency Ft according to the variation of the delta T in a certain time t1; and (5) outputting the Fobj to a driver of a variable-frequency compressor of the air-conditioner by using the frequency converter. The method can improve the comfort level, the using effect and the service life of the variable-frequency air-conditioner.

A motor control device includes a current detecting portion that detects phase current of one phase among three phase currents supplied from an inverter to a motor, and a current estimator that estimates phase current of phases other than the detected phase current by using a specified current value indicating current to be supplied to the motor, and derives control current corresponding to the specified current value from the estimated phase current and the phase current of one phase. The motor control device controls the motor via the inverter so that the control current follows the specified current value.

A communications satellite (201) has an on-board high speed packet switch for switching transmitted data packets. The packet switch (502) is part of a processor subsystem (501) which also includes a number of demodulators (5031 to 503n) demodulating signals received from an uplink downconverter. All of the processors in the processor subsystem (501) are organized into a loosely coupled, distributed, architecture of general purpose computer modules (601) and digital signal processor modules (602) having both primary and redundant processors and being connected to each other by dual redundant PCI buses. Software and firmware is layered and distributed redundantly over the processor modules (601, 602).

A wastewater pumping system includes a centrifugal pump operatively connected to an electric motor via a coupling. The speed of the electric motor is automatically varied responsive to the head or load realized by the pump of the system as it varies with the composition of the slurry mixture. A variable frequency drive is operatively connected to the motor and the electrical power supply that affects a shift or change in electrical frequency delivered to the electrical motor so that the speed of the motor and consequently the pump is varied. This allows the electrical power deliver to the system to remain substantially unchanged for varying loads realized by the pump.

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

Methods and apparatus for reducing the common mode voltage generated by eliminating zero-voltage vectors in a rectifier / inverter variable frequency drive (VFD) system includes comparing three phase voltages to each other to determine a maximum voltage in one phase, a minimum voltage in another phase and a middle voltage in still another phase, inverting phase voltages for one phase having the maximum voltage and another phase having the minimum voltage, comparing the phase voltages to a carrier wave to determine gating signals for three respective phases of the inverter, and inverting gating signals for the one phase having the maximum voltage and for another phase having the minimum voltage to reduce the common mode voltage in the motor. In one embodiment, the zero-voltage vectors are removed by relating a first plurality of gating signals and a plurality of sector logic signals in a logic table to a second plurality of gating signals that are applied to phases of the inverter

The invention relates to the technical field of bearing testing, in particular to a bearing integrated dynamic performance test device and method. The bearing integrated dynamic performance test device comprises a drive system, a transmission system, a measurement and control system, an environmental simulation system and a mechanical body structure. A motor is adopted by the drive system for driving. The measurement and control system controls the rotation speed of the motor. The transmission system is in a belt transmission mode or a coupler transmission mode. The measurement and control system is provided with a force sensor, a strainmeter, an eddy current transducer, a rotation speed sensor, a laser displacement sensor, a temperature sensor, a magnetic oil residue sensor, a pressure sensor, a flow sensor, an oil temperature sensor, an acceleration sensor and other related sensors used for bearing testing. The control system is driven in a servo mode, and is composed of a frequency converter, a hydraulic solenoid valve, a heating controller, a flow control device and a pressure control device. The environmental simulation system is adopted for simulating a real bearing testing working condition, and the performance and service life testing of the real bearing testing working condition is achieved.

A vehicle includes a motor for driving wheels WH, an inverter to drive the motor, and a control device to perform PWM control of the inverter. The control device performs synchronous PWM control in a case where an electric current supplied to the motor by the inverter or torque generated in the motor is larger than a threshold value; and performs the synchronous PWM control or non-synchronous PWM control in a case where the electric current or the torque is smaller than the threshold value and sets carrier frequency or a pulse number of the PWM control to be higher than the case where the electric current or the torque is larger than the threshold value. Thereby, it is possible to provide a vehicle of achieving reduction of noise, reduction of cost and improvement of fuel consumption in a balanced manner.

A method and system for converting an optical signal to electrical information signals, including demodulated baseband information signals and modulated baseband signals at multiple harmonics. In an embodiment, the optical information signal is amplitude modulated with information. The method converts an optical signal to electrical charge, accumulates the electrical charge, and periodically transfers the accumulated electrical charge to a storage device, whereby the periodically transferred electrical charge forms the electrical signals. An exemplary system includes an optical transducer and a universal frequency translator coupled to an output of the optical transducer. The optical transducer receives an optical signal and converts the optical signal to electrical charge. The universal frequency translator periodically transfers energy from the electrical charge and forms the electrical signals from the transferred energy. In an embodiment, the present invention converts an I and Q optical signal to electrical signals. In an embodiment, the present invention converts an optical signal to an RF electrical signal using relatively few components, while preserving information content.

A forced air cooling tower includes an upright casing, and elevated water distribution system disposed in an upper portion of the casing and one or more fans for drawing air through the tower. The tower also includes a catch basin for collecting the cooled air and a pump for circulating the cooled water through a condenser and back to the top of the tower and to the water distribution system. The cooling tower also includes a controller and a variable frequency device for regulating the flow of air through the tower. A first temperature sensor senses the temperature T1 of the hot process water delivered to the water distribution system and a second sensor senses the dry bulb temperature of the air leaving the tower Tdbt2. A third sensor senses the temperature of the cooled water leaving the tower. The controller such as a computer and variable frequency drive controls the speed of the fan to minimize the difference in T1 and Tdbt2. A submaster control prevents the fan speed from being further reduced when a predetermined T2 (temperature of the cooled water) is reached.