70 results about "Harmonic reduction" patented technology

A system and method for reducing harmonics in a circuit is disclosed. The system comprises a main rectifier, (n3-1)auxiliary rectifiers connected to the main rectifier, and an autotransformer connected to both the main rectifier and the auxiliary rectifiers which provides 2n-pulse rectification where n equals the number of phases of the system. The autotransformer generates (n3-1)auxiliary voltage sets, each auxiliary voltage set having an auxiliary voltage amplitude, k, and an auxiliary voltage phase, α, wherein k=4+2⁢3⁢cos⁢(θ-7⁢π6)and wherein α=sin-1⁢(3⁢sin⁢ ⁢θ-0.5k)assuming a main voltage amplitude of one and a main voltage phase of ninety degrees, wherein θ=180⁢°nand its integral multiples for all possible real values of k. The main rectifier has a main rectifier power rating, Pmdb wherein Pmdb≥(n+32⁢n)times the load power, and the auxiliary rectifiers each have an auxiliary power rating, Pauxdb, wherein Pauxdb≤(32⁢n)times the load power.

A mobile wireless communications device includes a housing and antenna supported by the housing. At least one circuit board is carried by the housing and has radio frequency (RF) circuitry operative with the antenna for receiving and transmitting RF signals through the antenna. A power amplifier is connected within a transmission line for amplifying RF signals to be transmitted over the transmission line to the antenna. An antenna switch is carried by the circuit board and connected to the antenna and RF circuitry. An RF shield surrounds the power amplifier and antenna switch isolates the power amplifier and antenna switch from the antenna and RF circuitry. A low pass filter has an input connected to the power amplifier and an output connected to the antenna switch for reducing any RF coupling of voltage standing waves of upper harmonic frequencies from the power amplifier into the antenna switch between the input and output of the low pass filter through the RF shield while maintaining transmission of signals through the transmission line at a desired fundamental frequency.

The invention is a harmonics reduction device for three-phase poly-wire power lines, which can more reliably eradiate harmonics current applied to an electric power system via a neutral line. The invention comprises an electric power system having three-phase poly-wire power lines in order to supply alternating-current (AC) power voltage to a load; a zigzag transformer in which windings connected with three-phase lines in the electric power system are wound through first and second legs, second and third legs, and third and first legs of a core having three legs, respectively, while varying direction of each magnetic flux, and an intermediate point of each winding is commonly connected with a neutral line of the electric power system and that of the load; and an open delta connection portion in which an winding connected with the neutral line of a load side is wound through the three legs so as to be connected with a neutral line of the electric power system.

The invention discloses a rotational joint module of a modularized reconfigurable robot. On the basis of planetary reduction, one level of harmonic reduction is added on motor output, a reduction ratio is improved, an output torque is added, and the transmission precision of the module is improved. An upper end cover and a lower end cover serve as installation joints, the flange-type design with locating seam allowances and pin holes is adopted, and the module is accurately and conveniently connected and located. All electric wires are arranged in a cage-type support, the upper end cover and the lower end cover and are isolated and protected by an outer cover, thereby avoiding the problem that the electric wires are coiled when a robot moves. Mechanical limit and electric limit are arranged in the module. On the basis of adopting an incremental coded disc, a rotating potentiometer is added to measure the assistant position of module movement, absolute position information is recorded under the condition of accidental power failure, and the system can continuously work after being electrified. The rotational joint module has the advantages of reasonable and simple structure, high precision and inner routing, is convenient to install and position and is safe and reliable to use.

The invention relates to a harmonic reduction hybrid power bicycle. A combined device formed by adopting a hollow high-speed motor, a hollow harmonic reducer and a hollow power synthesis mechanism operates on a central shaft of the bicycle, motor power and manpower are synthesized by the power synthesis mechanism and then used for driving the bicycle to travel through bicycle chains and a mechanical variable speed mechanism, thereby ensuring that, under different traveling conditions, the motor can be maintained to operate under the optimal designed state, accordingly, the harmonic reduction hybrid power bicycle, a veritable electric bicycle, can become the commonest non-motor vehicle used by human by taking the place of so-called electric bicycles and traditional pure-manpower bicycles at present owing to incomparable superiorities thereof, such as safety and convenience as great as traditional bicycle completely, low cost, low energy consumption and no pollution, etc.

The invention discloses a compensation control circuit beneficial to harmonic reduction of an active flyback power factor correction device. The flyback power factor correction device comprises an electro-magnetic interference (EMI) filter circuit F9, a rectifier filter circuit F10, a transformer T1, an absorbing circuit F11, a switch tube Q1, a primary inductive current sampling resistor R1, a diode D1, an output capacitor C1, an output current sampling resistor R2, an auxiliary reference power supply F12 and an auxiliary power supply F13, wherein the EMI filter circuit F9 is connected in parallel with an alternating current power supply; and the rectifier filter circuit F10 is connected with the output end of the EMI filter circuit. The compensation control circuit comprises a referencesignal sampling circuit F1, a first operating circuit F2, a second operating circuit F3, a comparison circuit F4, a pulse width modulation (PWM) control and drive circuit F5, a current sampling circuit F6, an isolating circuit F7, an output sampling feedback circuit F8 and the like. The invention aims to solve the problem of input current distortion of the conventional flyback power factor correction device in a critical conduction mode during high voltage input and light loading.

Method and apparatus for reducing harmonic distortion. In one embodiment, the method comprises determining an inverter output current waveform; determining a plurality of harmonic components of the inverter output current waveform; determining, based on the plurality of harmonic components, a plurality of harmonic compensation components; and generating a compensating current comprising the plurality of harmonic compensation components

Switched power converter with hold-up time and harmonics reduction connected to an AC power mains through a first rectifier means (13) and connected to conversion means (19) supplying a regulated voltage.An energy storage means (16) connected in parallel with the rectifier means (13), absorbs or supplies current to the conversion means (19), by adapting the conducting periods of two switching devices in such a way that determines the voltage level on the storage means (16) and assures a sinusoidal current at input terminals (11, 12).The two switching devices are switched in a complementary manner by means of a first control means included in the energy storage means (16).

A three-phase filter has first, second, and third power source connectors and first, second, and third load connectors. A separate phase line filter is connected between each pair of power source and load connectors. Each phase line filter includes a line winding connected between the power source and load connectors for a phase line and includes a first shunt winding, resistor and capacitor connected in series between that load connector and the load connector for another phase line. The line and shunt windings for a given phase line filter are wound on a core in directions so that one winding produces magnetic flux having an opposite polarity to the magnetic flux produced by the other winding. The magnetic coupling of those windings, mitigates harmonic currents that otherwise flow in either direction between the power source and load connectors.

An apparatus for selecting one of a first encoding algorithm and a second encoding algorithm includes a filter configured to receive the audio signal, to reduce the amplitude of harmonics in the audio signal and to output a filtered version of the audio signal. First and second estimators are provided for estimating first and second quality measures in the form of SNRs of segmented SNRs associated with the first and second encoding algorithms without actually encoding and decoding the portion of the audio signal using the first and second encoding algorithms. A controller is provided for selecting the first encoding algorithm or the second encoding algorithm based on a comparison between the first quality measure and the second quality measure.

In one aspect, in general, the invention features a control system configured for use with a three-phase PWM converter. The control system receives an input signal from a three-phase power supply and provides an output signal at a DC link. A voltage-separating module generates on the basis of the input signal a positive sequence voltage component and a negative sequence voltage component in a rotating reference frame. A reference current computation module uses at least the positive sequence voltage component and the negative sequence voltage component to compute a first reference current and a second reference current. A current regulating module uses at least the first reference current and the second reference current to generate a command signal. The command signal is provided to a driving circuit of the three-phase PWM converter for generating a regulated DC bus voltage at the DC link.

The invention provides a five-axis robot. The five-axis robot comprises a lifting mechanism, a second rotary shaft base, a first servo motor, a first harmonic reduction gear, a large arm, a second harmonic reduction gear, a small arm, a second servo motor, a transmission mechanism, a motor, a third harmonic reduction gear and an overturning unit, wherein the second rotary shaft base is arranged on the lifting mechanism, the first servo motor is arranged on the second rotary shaft base, and the first harmonic reduction gear is arranged at the output end of the first servo motor and connected with the large arm; the second harmonic reduction gear is arranged on the upper surface of one end of the large arm and connected with the small arm; an output shaft of the second servo motor is connected with the second harmonic reduction gear; the transmission mechanism is arranged in the small arm, and the motor is connected with a drive wheel of the transmission mechanism; and the third harmonic reduction gear is connected with a driven wheel of the transmission mechanism and the overturning unit. Compared with the prior art, the five-axis robot has the lifting and overturning functions, the application range is wider, and multidimensional operation on products is facilitated. The technical difficulty that a traditional robot cannot overturn is broken through, and the five-axis robot is simple in structure, low in cost, large in load and durable.

A three-phase filter has first, second, and third power source connectors and first, second, and third load connectors. A separate phase line filter is connected between each pair of power source and load connectors. Each phase line filter includes a line winding connected between the power source and load connectors for a phase line and includes a first shunt winding, resistor and capacitor connected in series between that load connector and the load connector for another phase line. The line and shunt windings for a given phase line filter are wound on a core in directions so that one winding produces magnetic flux having an opposite polarity to the magnetic flux produced by the other winding. The magnetic coupling of those windings, mitigates harmonic currents that otherwise flow in either direction between the power source and load connectors.

A power control system includes a power reduction module operable to reduce power to a connected load, a switching module operable to selectively transfer power directly to the load or to the power reduction module, a harmonic reduction module connected to an output of the power reduction module for reducing signal harmonics from power transferred to the load, a controller linked to the switching module to provide control signals, a resistor coupled between the switching module and the power reduction module, and a resistor voltage monitor coupled between the switching module and the resistor, wherein the resistor voltage monitor measures a voltage across the resistor and sends voltage measurement data to the controller. The power control system is connected to various types of loads.

A wireless transmitter is disclosed. The wireless transmitter includes a digital signal generator arranged to generate a digital signal for transmission, a digital-to-analog converter arranged to convert the digital signal for transmission into analog form and a non-ideal amplifier arranged to amplify the analog signal for transmission. At least one harmonic reduction signal generator is arranged to generate at least one digital harmonic reduction signal and a summing junction is arranged to add the digital signal for transmission with the at least one harmonic reduction signal to form a combined signal. The non-ideal amplifier amplifies the combined signal to form an analog output signal. A controller is coupled to the digital signal generator and the at least one harmonic reduction signal generator.

An electromechanical operation mechanism of propeller for water turbine can be used to adjust the aperture of propeller for water turbine in stead of hydro-cylinder system. The output shaft of servomotor and reduction gear will be connected with the trapezoidal screw in main shaft of machine set as the up section of trapezoidal nut sheath to be connected to the screw thread of trapezoidal screw and the down end to operation shaft which directly connects with the operation mechanism of propeller in rotary wheel body of water turbine. The servomotor and reduction gear will be fixed at up end of main shaft for machine set through supporting frame and be connected to the main shaft by bilateral thrust bearing. It is better to use DC servomotor and harmonic reduction gear and there will a feedback device near trapezoidal nut sheath to reflect the rotary angle changes of propeller.

Converter and method for controlling a converter with power semiconductor switches, having a filter (1) which is connected to the power semiconductor switches and having a drive circuit (4) which is connected to the power semiconductor switches for the purpose of modulation, wherein, as a result of the modulation, a fundamental at a fundamental frequency (fGS) is generated in a passband (P) of the filter (1), modulation products are generated in a first frequency band (FB1), in a second frequency band (FB2) and in an intermediate frequency band (ZFB) which is formed between the first frequency band (FB1) and the second frequency band (FB2), the modulation products in the intermediate frequency band (ZFB) are reduced in comparison with the modulation products in the first frequency band (FB1) and the modulation products in the second frequency band (FB2), and the intermediate frequency band (ZFB) is generated, in a resonant range (R) of a resonant frequency (fres) of the filter (1), between the passband (P) and an attenuation range (D) of the filter (1). A converter having an output-side sinusoidal filter whose dimensions have been reduced is thus obtained.

The invention belongs to the technical field of speed reducers, and relates to a planetary harmonic combined speed reducer. A gear shaft, a planetary gear, a planet carrier, a rigid wheel and a pin shaft form a one-stage planetary reduction gear train, the rigid wheel is fixed, the gear shaft is used for being connected with external input equipment as an input part, and plays a role in a sun wheel at the same time, the planetary gear is meshed with a first inner gear ring of the rigid wheel and a gear part of the gear shaft at the same time so as to rotate around the pin shaft and rotates around the gear shaft at the same time, and the planet carrier serves as an output part and transmits the output to a wave generator. The wave generator, a flexible wheel, the rigid wheel and a first bearing form a secondary harmonic reduction gear train, under the action of the wave generator, the flexible wheel is deformed forcibly, an outer gear ring is in meshed transmission with a second inner gear ring, and the first bearing is connected with external output equipment so as to output power. The first inner gear ring and the second inner gear ring are arranged on the rigid wheel, so that a planetary reduction train and the harmonic reduction train share an inner gear, the number of parts is reduced, and the reducer has the advantages of being simple and compact in structure, convenient to assemble, high in speed reduction ratio, small in size, high in transmission precision and the like.

A method and system for managing a dual rectifier uninterruptable power supply, comprising activating each of said rectifiers to provide an output DC voltage, monitoring a level of operation of the uninterruptable power supply and deactivating a selected one of said dual rectifiers when a level of operation of said two activate rectifiers is less than a first predetermined level of operation.

A device for converting a DC voltage into an AC voltage includes a passive electronic filter having a first and second energy storage element, a third energy storage element placed between the first and second energy storage elements, a fourth energy storage element connected between a junction of the first energy storage element and the third energy storage element and an AC terminal and a fifth energy storage element connected between a junction of the second energy storage element and the third energy storage element and the AC terminal. The energy storage elements are of two different types, capacitive and inductive, with values selected to provide reduction of frequency components at two times the fundamental frequency of the AC voltage and at three times the fundamental frequency of the AC voltage.

The invention provides a mechanical device for applying a harmonic reducer to bothway transmission. The mechanical device comprises a motor, a box, a switching mechanism, a clamping mechanism, a harmonic reduction mechanism, a bearing and a coupler. The mechanical device can be applied to a mechanical system needing bothway transmission. When an output shaft of the harmonic reducer serves as the input end to do reverse transmission, a wave generator, a flexible gear and a rigid gear of the harmonic reducer are locked through the clamping mechanism, the harmonic reducer is not connected with the box, and the harmonic reducer does not have the speed changing effect at the time and is equivalent to a coupler with the transmission ratio being 1:1. System power passes through the harmonic reduction mechanism and is not influenced by the reduction ratio of the harmonic reduction mechanism, and therefore the dragging resistance is smaller; and when the mechanical system uses an output shaft of the motor as the input end to do forward transmission, the locking state of the wave generator, the flexible gear and the rigid gear of the harmonic reducer can be ended through the switching mechanism, meanwhile the harmonic reducer is installed on the box, the system power is subject to the reduction ratio effect of the harmonic reduction mechanism, and therefore the large output torque can be obtained.

The invention relates to an energy storage bidirectional converter system for harmonic compensation and a control method, and belongs to the technical field of harmonics reduction. The invention solves the problem of excessive nonlinear load harmonic current by utilizing the existing energy storage bidirectional converter in the micro grid, and optimizes the power quality of the micro grid. The invention eliminates the influence of the long distance feeding line and improves the harmonic compensation effect by directly collecting the nonlinear load side harmonic information. A voltage and current model is established; the harmonic current characteristic value and the PCC point characteristic emitted by the nonlinear load are extracted by a signal measurement coding device; the communication information amount is compressed, and the harmonic information is transmitted through a narrowband wireless communication device; and a local controller receives the information of the signal measurement coding device and then decodes the information, so as to restore the real load harmonic current, thereby realizing the closed-loop proportional resonance control of the energy storage bidirectional converter, and realizing the accurate compensation of the harmonic current of any number of times. The invention has the advantages of low cost, excellent effect and simple engineering realization.

The invention belongs to the technical field of reducers, and relates to a planetary harmonic combination reducer. An input shaft, a sun gear, a planet gear, a planet carrier and a flexible wheel form a first-stage planetary reduction gear train, the portion of a flexible wheel annular part is fixed, the input shaft is used for being connected with an external input device to serve as an input portion, the sun gear rotates along with the input shaft, the planet gear is simultaneously engaged with the sun gear and the flexible wheel, autoroatation around the axis of the planet carrier is carried out while revolution around the input shaft is carried out, forced outward expansion deformation is generated at the meshing portion of a flexible wheel cylinder portion and the planet gear, and inward shrinkage deformation is generated in a middle area of the cylinder portion. The sun gear, the planet gear and the planet carrier form a wave generator, and the wave generator, the flexible wheel, a rigid wheel and a first bearing form a second-stage harmonic reduction gear train, the portion of a flexible wheel annular portion is fixed, the wave generator is used as input, and the rigid wheel is used for being connected with an external output device for outputting power. The flexible wheel participates in movement of the first-stage planetary reduction gear train and the second-stage harmonic reduction gear train, the high reduction ratio is achieved, the space is effectively used, and processing and assembling are easy.

A method and system for managing a dual rectifier uninterruptable power supply, comprising activating each of said rectifiers to provide an output DC voltage, monitoring a level of operation of the uninterruptable power supply and deactivating a selected one of said dual rectifiers when a level of operation of said two activate rectifiers is less than a first predetermined level of operation.

The invention provides a harmonic reducer. The harmonic reducer comprises a wave generator assembly, a fixed gear, a flexible gear and an output assembly, wherein the flexible gear is cylindrical andcan generate elastic deformation under the action of external force, the flexible gear comprises a friction ring part, the flexible gear is extruded by the wave generator assembly to be deformed intoan elliptical flexible gear, the elliptical flexible gear is not in contact with the fixed gear at two end points of a long shaft of the oval flexible gear, and the elliptical flexible gear is in contact with the fixed gear at two end points of a short shaft of the elliptical flexible gear. According to the harmonic reducer, toothless harmonic reduction is carried out through a friction driving principle, so that a very high reduction ratio can be realized, and the transmission efficiency of the harmonic reducer is greatly improved. The invention further provides a driver. The driver can be directly connected with the toothless harmonic reducer through various motors, and the driver is small in size, light in weight and more suitable for being applied to the field of service robots.

The invention relates to a horizontal harmonic reduction rotating table. The horizontal harmonic reduction rotating working table comprises a horizontal mounting seat, a rotating assembly and a clampassembly. The horizontal mounting seat comprises a first cavity, a second cavity and a connecting portion connecting the first cavity with the second cavity. A wire groove being communicated with thefirst cavity and the second cavity is formed in the connecting portion. The rotating assembly comprises a servo motor, a harmonic reducer and a working chuck. The servo motor is mounted in the first cavity. The input end of the harmonic reducer is in transmission connection with the output end of the servo motor. The output end of the harmonic reducer is in transmission connection with the workingchuck. The clamp assembly is fixedly mounted on the working chuck. A clamp pressing screw is mounted on the clamp assembly in a matched manner. The clamp pressing screw can fix a product on the clampassembly. The horizontal harmonic reduction rotating table has the beneficial effects that the harmonic reducer using the zero back clearance is connected with the servo motor, so that the defect that the angle is inaccurate due to the gear back clearance generated when a common gear matched with a speed reducer rotates forwards or reversely is eliminated.

An apparatus for selecting one of a first encoding algorithm and a second encoding algorithm includes a filter configured to receive the audio signal, to reduce the amplitude of harmonics in the audio signal and to output a filtered version of the audio signal. First and second estimators are provided for estimating first and second quality measures in the form of SNRs of segmented SNRs associated with the first and second encoding algorithms without actually encoding and decoding the portion of the audio signal using the first and second encoding algorithms. A controller is provided for selecting the first encoding algorithm or the second encoding algorithm based on a comparison between the first quality measure and the second quality measure.

The invention discloses a harmonic reduction gear with a high tooth shape. The inner surface of an annular rigid wheel is provided with inner teeth, and the annular rigid wheel is provided with a harmonic generator. The harmonic generator comprises a rigid cam with the elliptical profile and a soft bearing embedded on the outer periphery of the rigid cam. The outer periphery of the bearing of the harmonic generator is sleeved with a soft wheel, and the outer surface of the soft wheel is provided with outer teeth matching with the inner teeth of the annular rigid wheel. The soft wheel is coaxial to the annular rigid wheel. The harmonic generator is driven by a motor to serve as a rotation driving source. The pressure angle of the tooth root of at least one of the annular rigid wheel and the soft wheel is smaller than a standard pressure angle of tooth shape of a standard rack. The harmonic reduction gear is reasonable in structure; on conditions that service life and strength of a tooth slotting cutter for machining the inner tooth of the annular rigid wheel are free of reduction and fatigue strength of the outer teeth of the soft wheel is also free of reduction, the rotary torque of the harmonic reduction gear at high reduction ratio can be increased.