128results about How to "Reduce harmonic interference" patented technology

An AC to DC converter with harmonic suppression is provided. The harmonic suppression is provided by forcing an instantaneous current conflict between series connected rectifier bridges 54, 80, such that a voltage waveform at 6 times the AC supply frequency of the AC supply is automatically generated. This waveform is then injected via a injection circuit to give harmonic cancellation.

The invention relates to a brushless doubly-fed motor excitation control system, which is characterized by comprising a PWM (Pulse-Width Modulation) rectifying unit, a first current sensor, a smoothing reactor, a contactor, an excitation controller and an inverter unit, an operation and display unit, an energy storage device, a BOOST reactor, a soft start circuit, a first voltage detection circuit and a second voltage detection circuit. The brushless doubly-fed motor excitation control system can always keep a speed-variable load-variable constant-frequency and constant-voltage power generation state when a brushless doubly-fed motor is at an electric operating state, the rotating speed of a brushless rotor rapidly changes and the load condition is within a larger range; and when the brushless doubly-fed motor is at the electric operating state, the brushless doubly-fed motor excitation control system can finish rapid adjustment of the rotating speed of the brushless rotor by excitation control and realizes multiple electric operating modes, such as synchronous operating, asynchronous operating and doubly-fed speed adjustment. When the load condition changes in a larger range, the brushless doubly-fed motor excitation control system can always keep the hard mechanical property of a synchronous motor. The invention also comprises the control method using the brushless doubly-fed motor excitation control system.

An AC to DC converter with harmonic suppression is provided. The harmonic suppression is provided by forcing an instantaneous current conflict between series connected rectifier bridges 54, 80, such that a voltage waveform at 6 times the AC supply frequency of the AC supply is automatically generated. This waveform is then injected via a injection circuit to give harmonic cancellation.

The invention discloses a bearing fault identification method based on LMD (Local Mean Decomposition) and wavelet de-noising. First, a fault vibration signal of a rolling bearing is decomposed through LMD to get a plurality of natural vibration composition PF components, and suitable PF components are selected according to the principle of maximum kurtosis and a cross correlation coefficient. Then, the selected PF components are de-noised through wavelet de-noising, and high frequency bands are superposed and reconstructed. Finally, experimental results on an MFS (Machine Fault Simulator) show that the method has obvious advantages compared with the traditional bearing fault diagnosis method.

The present disclosure relates to interference coordination methods and apparatuses, base stations, user equipments, and computer readable storage media. The method for interference coordination includes: determining whether there is intra-device interference between uplink and downlink transmission in two frequency bands by a user equipment UE; if the UE has intra-equipment interference between uplink and downlink transmission in two frequency bands, sending configuration information to the UE to configure Information is used to instruct the UE to stop sending uplink transmission of at least one frequency band in two frequency bands or to power back uplink transmission of at least one frequency band in two frequency bands during a time interval in which the base station sends control data for downlink transmission in each frequency band Retreat The embodiments of the present disclosure can achieve the purpose of reducing the control channel interference in the device.

The invention discloses a touch detection method of a mutual capacitance touch screen. The method comprises collecting noise signals of each reception channel, conducting spectral analysis on the noise signals and finding out a frequency point with the minimum power under the condition of sending no excitation signal; sequentially sending excitation signals generated at selected frequency points of each reception channel to the touch screen through a drive circuit; converting charge transmitted from a capacitor to be detected through a charge amplifier into voltage signals simultaneously by each reception channel, simultaneously forming a first-order high-pass filter by using the charge amplifier, filtering low-frequency interference signals, using an analog-digital converter to convert electrical signals into digital signals, respectively mixing the digital signals and sinusoidal signals and cosine signals which are generated at the selected frequency points after filtering the digital signals, conducting coherent integration on output of a mixer, obtaining a range of a coherent integration result to serve as a final measured value, and judging whether touch exists or not by detecting changes of the measured value. The method is good in noise immunity, low in harmonic interference, small in use of storage resources and high in computational accuracy.

The present invention relates to control device and method for solar photovoltaic electricity generating system. The apparatus of the present invention consists of solar plates, control device, monitor, AC load, AC power network, etc. The system has square solar cell matrix connected to networking inverter unit, AC power network connected to AC load, the networking inverter unit with output connected between AC power network and AC load, upper computer connected to the monitor, the monitor connected to man-computer interface unit, and RS232 interface for the connection between man-computer interface unit and the upper computer. The present invention has the advantages of simple circuit, great voltage and current capacity, high work frequency, low switch loss, etc.

The invention discloses a vibroseis excitation method of seismic data acquisition. Sub scanning signals are divided into signals with intersection frequency band and signals without intersection frequency band. The encoding is carried out in an order from a low frequency band to a high frequency band. The no-intersection-frequency-band sub scanning signal arrangement matrix scanning is carried out. Each scanning sub signal of a first row in a no-intersection-frequency-band sub scanning signal matrix or a force signal corresponding to the signal and a simultaneously excited parent record are used to carry out correlation or convolution. An earthquake sub record which is excited and formed by the scanning sub signal is separated, separated earthquake sub records which are formed by a completed scanning sequence are superimposed to form a sub seismic record, and the vibroseis frequency division simultaneous excitation is completed. Under the premise of maintaining highly efficient acquisition, adjacent gun interference and harmonic interference are greatly reduced, and the daily efficiency is 50 times of that of the conventional scanning.

The invention relates to an integrated gate-commutated thyristor (IGCT)-based hybrid cascaded H-bridge multi-level high-voltage inverter, which belongs to the technical field of electric drive. The inverter comprises a rectification unit, a DC unit, an inversion unit and a dv / dt filter, wherein the secondary side of a multi-winding rectifier transformer is connected with the input of the rectification unit; the output of the rectification unit is connected with the input of the DC unit; the output of the DC unit is connected with the inversion unit; and the output of the inversion unit is connected with the dv / dt filter. The inverter solves the problem that 10 kV high-voltage high-capacity output is obtained without realizing direct series connection by IGCT devices, less impacts a power grid in a working process, increases the sine degree of output voltages, has relatively lower difficulties in control and enhanced reliability, improves the working stability of a system, effectively inhibits current harmonics on a power grid side, and makes the distortion rate of line current on an input side meet standard requirements.

The invention discloses a plasma ignition and combustion stabilization device for IGBT (insulated gate bipolar transistor) rectification power supply. The plasma ignition and combustion stabilization device for the IGBT rectification power supply comprises a collision type pulverized coal concentration fractional combustion pulverized coal burner and a plasma spray gun, wherein the plasma spray gun generates high-temperature flame at the temperature of about 4000DEG C to ignite pulverized coal in an inner-layer combustion chamber of the pulverized coal burner; heat released from the burning of the pulverized coal in the inner-layer combustion chamber then ignites pulverized coal in an outer-layer combustion chamber to realize the stable combustion of pulverized coal flame; the collision type pulverized coal concentration fractional combustion pulverized coal burner comprises a primary air dust inlet, a straight pipe section, a taper pipe section, an outer nozzle, a collision concentration block, a collision concentration ring, the inner-layer combustion chamber, the outer-layer combustion chamber, an inner-layer combustion chamber disturbance block, an outer-layer combustion chamber rear disturbance block and an outer-layer combustion chamber front disturbance block; and the plasma spray gun comprises a cathode, a magnetic field coil, a spiral air chamber, an anode, a nozzle and a gun body. The plasma ignition and combustion stabilization device for the IGBT rectification power supply is applied to the starting ignition and the combustion stabilization stage of a pulverized coal fired boiler to replace the traditional big oil gun ignition and combustion stabilization mode, coal is used for replacing oil, and therefore the purpose of saving cost is achieved.

The invention discloses an integrated variable frequency fracturing pumping device control system and control method. The integrated variable frequency fracturing pumping device control system comprises a high voltage electric input unit, an integrated container, and a variable frequency integrated machine; the integrated container comprises a power supply and distribution unit connected with a high voltage circuit breaker, the power supply and distribution unit is connected with and provides power for a main touch screen display, a main controller, an auxiliary controller, an auxiliary touchscreen display, and the variable frequency integrated machine correspondingly, and the main controller is connected with a remote control station and a camera system correspondingly; the main controller is further connected with the fluid end and the power end of a fracturing pump and an illuminating system; the main controller is further connected with a fracturing truck; the variable frequency integrated machine comprises a detection system, a temperature control system, and a frequency converter, wherein the detection system and the temperature control system are connected with the main controller correspondingly, the frequency converter is connected with the auxiliary controller, the frequency converter is connected with a variable frequency motor, and the variable frequency converteris connected with the fracturing pump. According to the integrated variable frequency fracturing pumping device control system and control method, the whole control system is divided into two independent modules, the structure adopts an integrated modular design, the mounting space is compact, maintenance is convenient, and assembly is flexible.

The low-harmonic AC motor controller includes monochip microprocessor MCU, zero-crossing detection circuit, control input circuit, SCR drive circuit, bi-directional SCR and power circuit. By means of zero-crossing triggering to alter the conducting in set period and phase shift triggering, the on / off of the bi-directional SCR is controlled to output continuously adjustable voltage. The control process includes the following steps: initializing before reading the set output power, performing the output power control operation, and producting interruption by the MCU after the zero-crossing detection circuit detects the AC zero-crossing signal to output triggering pulse. The controller and the control method make full use of the zero-crossing triggering and phase shift control, reduce greatly the harmonic and electromagnetic radiation, and control the output of great power AC motor in continuously adjustable mode radically.

The invention discloses a radio-frequency circuit and a method for reducing harmonic interference of the radio-frequency circuit. The circuit comprises a radio-frequency transceiving module, a matching module, a shunt switch and a filter module; one end of the matching module is connected with the radio-frequency transceiving module, and the other end is connected with the filter module via the shunt switch. The method comprises the following steps: S10, detecting the frequency of signals; and S20, selecting a signal channel according to the frequency detection result of the signals. The radio-frequency circuit can recognize signals and transmit the signals in different channels, and can further filter more harmonic interference generated therein, thus greatly reducing harmonic power no matter on conduction or coupling, and solving the problem of electromagnetic compatibility stray.

The invention belongs to the technical field of nervous system disease electrical stimulation, relates to a biological tissue time domain interference electrical stimulation device and a using methodthereof. The time domain interference electrical stimulation device comprises an AC signal source, a signal filtering module, a voltage control conversion module, a linear power source and a power source filtering module; two pairs of stimulation electrodes are attached to a body surface of a tissue to be stimulated, and two sinusoidal alternating electric fields at the frequency f and the frequency f+Delta f are applied to the two pairs of electrodes respectively, and when the two electric fields with similar frequencies meet, an interference phenomenon in the time domain can occur, and an envelope electric field is formed; and the frequency of the envelope electric field is the frequency difference between the two sinusoidal alternating electric fields. The electrical stimulation changepeak of the envelope electric field can be intensely focused in a specific region of the tissue in a spatial dimension through the time domain interference technique, so the purpose of non-invasive and precise regulation of electrical stimulation of a tissue targeted region only by adjusting the positions of the surface mount electrodes and the stimulation current ratio of the two pairs of electrodes.

The ultrasound motor includes main body, and rotor and stator inside the main body. Piezoelectric elements are pasted on stator. Characters are that number of piezoelectric element is m or integral time of number m, where as prime number larger than 2; amount of piezoelectric element is 3 or integral time of 3; piezoelectric elements are evenly distributed on stator; direction of polarization of piezoelectric element is consistent to pasted surface relatively. The method includes steps: (1) obtaining polyphase source including M phases, and phase difference as 2Pi / M, and M as integer large than 2; (2) applying voltage in each phase on corresponding piezoelectric element in ultrasound motor. The output of power supply in three phases is AC sinusoidal voltage in 120 degrees of phase difference, AC square wave voltage, or modulated AC pulse voltage in mode of pulse width modulation. Features are: stable output moment, and small harmonic interference.

The invention discloses a new energy power station dynamic reactive power compensation equipment application method. The improved content is as follows: (1) the dynamic reactive power compensation equipment is connected onto a low voltage-side bus of a three-winding boost transformer, the middle voltage side of the three-winding boost transformer is connected with gathered new energy electric power, and the two are isolated via the transformer; (2) voltage at the high voltage side of the new energy power station serves as reactive power needed by a calculation system for calculating reference voltage and control target voltage; and (3) a novel electronic current voltage combined transformer is applied to a measurement control system for the dynamic reactive power compensation equipment. In view of problems of poor operation stability of the new energy power station and disqualified electric power quality, a dynamic reactive power compensation configuration technology which can be applied to grid-connected power generation of the new energy power station and meet grid requirements is brought forward, a dynamic reactive power compensation equipment mounting site is changed, the new energy collecting system and the reactive power compensation equipment can be effectively isolated, the problems of operation stability of the new energy power station compensation equipment and electric power quality can be solved, and operation stability of the reactive power compensation equipment is improved.

The invention discloses an inter-band uplink carrier aggregation radio frequency circuit, an antenna device and electronic equipment. The inter-band uplink carrier aggregation radio frequency circuitcomprises a radio frequency transceiver, a primary antenna, a first secondary antenna, a first front-end radio frequency module and a second front-end radio frequency module; and the radio frequency transceiver is connected with the primary antenna by the first front-end radio frequency module and is also connected with the first secondary antenna by the second front-end radio frequency module, afirst frequency band uplink signal transmitted by the radio frequency transceiver is transmitted to the primary antenna by the first front-end radio frequency module, and a second frequency band uplink signal transmitted by the radio frequency transceiver is transmitted to the first secondary antenna by the second front-end radio frequency module so as to implement carrier aggregation of the firstfrequency band uplink signal and the second frequency band uplink signal. The uplink signals on the corresponding frequency bands are transmitted to the primary antenna and the secondary antenna by different front-end radio frequency modules so a to implement inter-band uplink carrier aggregation; and by isolation of the primary and secondary antennas, harmonic interference in the inter-band uplink carrier aggregation process is reduced.

The invention relates to a light-adjustable light-emitting diode (LED) drive circuit. The light-adjustable LED drive circuit is strong in anti-electromagnetic interference, high in power factor and high in reliability. The light-adjustable LED drive circuit comprises an anti-electromagnetic interference unit used for filtering external electromagnetic interference, a power factor correction unit used for improving the power factors of a power supply, a bridge rectifier circuit used for converting alternating current electric energy into direct current electric energy, a light modulator used for modulating voltage input into a voltage transformation rectifying circuit, a drive unit used for supplying electric energy to the light modulator, a voltage transformation rectifying circuit providing work current for an an LED light-source unit, a feedback circuit used for feeding back the work voltage of the voltage transformation rectifying circuit to a switch control circuit, the switch control circuit used for controlling output current of the voltage transformation rectifying circuit, and the LED light-source unit.

The invention provides an antenna device and a mobile terminal. The antenna device comprises a first antenna, a second antenna, a front end module, a transceiver and a first filtering module, wherein the transceiver is provided with a first receiving port and a first transmitting port, and the first filtering module is used for filtering signals beyond a first preset frequency band; and the first receiving port, the first filtering module and the first antenna are connected in sequence to form a receiving channel of auxiliary carrier components of the first preset frequency band, and the first transmitting port, the front end module and the second antenna are connected in sequence to form a transmitting channel of the auxiliary carrier components of the first preset frequency band. The antenna device provided by the invention has the beneficial effects of reducing harmonic interference.

The invention relates to application of high-voltage variable-frequency control system in mine winder. Wherein, with asynchronous motor flexible draught closed loop as control strategy, generating proper frequency and amplitude and three-phase sine signal command by the controller according to error between given and feedback rotation speeds to send to high-voltage frequency converter to output ac power accorded with said request to drive motor with running performance rigorous coincidence with request; using IGBT chopping-wave resistance braking mode or of regenerative braking controlled rectifier for motor electric brake. This invention improves speed regulation quality of winder obviously, saves 30-40% energy, increases power factor more than 0.96, and solves difficulty of high-voltage heavy-power motor in four operating conditions.

The invention provides a method for processing harmonic interference and a mobile terminal, wherein the method for processing the harmonic interference comprises: detecting a current working scene ofa radio system of the mobile terminal; and controlling the nonlinear device in the radio frequency system to operate in the linear region when harmonic interference is generated in the current workingscene of the radio system of the mobile terminal, wherein when the nonlinear device operates in the linear region, the input signal and the output signal of the nonlinear device are linearly correlated. The invention is capable of improving the linearity of the working state of the nonlinear device, thereby reducing harmonic interference and improving the radio frequency performance. Moreover, inthe embodiment of the invention, the radio frequency circuit is simple, and the circuit design cost may be saved.

The invention discloses a transverse flux permanent magnetic or reluctance permanent magnetic motor of a ring body box structure, and aims at manufacturing an integrated phase stator and phase rotor, installing a discrete iron core and a winding thereof, and creating an odd-even electromagnetic switching way of the phase rotor core and phase stator iron core. A phase stator ring body is provided with two series of odd-even iron cores and two windings which are in serial connection with the iron cores inside a left ring body box, a middle ring body box and a right ring body box, and three columns of iron core end surfaces are exposed out of an inner ring of the ring body box; a phase rotor ring body is provided with a circumferential array phase rotor iron core with an E-shaped cross section inside the left ring body box and the right ring body box, a left magnetic pole and a right magnetic pole of the E-shaped iron core are communicated with each other, a permanent magnet or a reluctance and permanent magnetic material laminated body is embedded between a middle magnetic pole and a right magnetic pole of each iron core in odd number, a non-magnetic steel structural body is embedded between the middle magnetic pole and the right magnetic pole, and components which are assembled in the even-number iron core and the odd-number iron core are replaced laterally; the polarity directions of the permanent magnet or the reluctance and permanent magnetic material laminated body in the odd-number iron core is identical to that of the permanent magnet or reluctance and permanent magnetic material laminated body in the even-number iron core, and three columns of iron core end surfaces are exposed out of an outer ring of the ring body box; and the phase stator ring body and the phase rotor ring body are assembled in a segmentation way along the axial direction. The transverse flux permanent magnetic or reluctance permanent magnetic motor is applicable to the motor or a generator.

The invention provides an antenna device and a mobile terminal. The antenna device comprises an antenna, a front end module, a first power amplifier, a first filter and an anti-interference module; the antenna is connected with the front end module, the front-end module and the first power amplifier are connected to form a first access, the front-end module, the first filter and the first power amplifier are connected in sequence to form a second access, and the anti-interference module is connected with the first power amplifier; and the anti-interference module is used for acquiring a working frequency band of a carrier in real time, controlling the first power amplifier to close the first access and open the second access when the working frequency band of the carrier satisfies a preset condition, and controlling the first power amplifier to open the first access and close the second access when the working frequency band of the carrier does not satisfy the preset condition. The antenna device provided by the invention has the beneficial effects of reducing the harmonic interference during carrier aggregation.

The invention discloses a method of determining generator grid connection synchronous closing pulse transmission time, which comprises steps: S100, grid voltage and generator-end voltage in each cycleare acquired; S200, the effective value of the difference between the grid voltage and the generator-end voltage in each cycle is calculated; S300, the effective values of the voltage differences inmultiple cycles are stored to form a voltage difference effective value sequence, and a time sequence with the values to be consistent with the effective value sequence is stored; S400, according to the voltage difference effective value sequence and the time sequence, the correlation coefficient between the voltage difference effective value sequence and the time sequence is calculated, and a linear fitting expression for the voltage difference effective value sequence and the time sequence is calculated at the same time; and S500, according to the correlation coefficient and the linear fitting expression, whether to transmit closing pulses is judged.

The invention discloses a method for controlling alternating current digital coding. A controller uses a power driver member to performing digital pulse coding on a trailing edge of positive and negative half waves of the alternating current, each half wave can be used for coding a coding bit, and a purpose of transmission of a digital controlled signal by using an AC power line. The provided controlling method uses the AC power line for transmission of the digital controlled signal, under condition that a control line is not added, digital control of loop equipment can be realized, fewer elements can be required by a system, and cost of the system is reduced. The digital coding method realizes accurate positioning control, compared with a phase-cut dimming system, the controlling method can greatly reduce harmonic wave interference, and can increase the reliability of the system.

The invention discloses an energy storage charging power supply device for connecting an electric automobile with an intelligent power grid. The energy storage charging power supply device comprises a power grid end filter circuit, a static switch, an active power factor correction circuit, an inversion circuit, a bus super capacitor, a bidirectional direct-current / direct-current (DC / DC) converter and a battery end filter circuit, wherein the static switch is connected with three-phase alternating current of the power grid through the power grid end filter circuit; the input end of the active power factor correction circuit is connected with the static switch, and the output end of the active power factor correction circuit is connected with the bus super capacitor; the bus super capacitor is connected with the static switch through the inversion circuit, and then is connected with the battery end filter circuit through the bidirectional DC / DC converter; the battery end filter circuit is connected with a power battery; and the static switch, the active power factor correction circuit and the inversion circuit control the transmission direction of energy between the power grid and the power battery. According to the energy storage charging power supply device, large-capacity batteries can be charged quickly; furthermore, the energy storage charging power supply device has high charging efficiency and a rational design, and is convenient to use.

The invention relates to a pumping unit controller, particularly to an intelligent control method capable of reducing higher harmonics for a pumping unit. The pumping unit is powered by a three-phase asynchronous motor, a multi-stage variable-speed motor or a permanent magnetic synchronous motor. A filter circuit, a direct current voltage and current detection circuit, a phase reference circuit, an autodyne phase adjusting circuit, a digital signal processor (DSP) control circuit, an alternating current (AC) detection circuit and a sine pulse width modulation (SPWM) unit are included. The intelligent control method is characterized in that the SPWM unit comprises a microprocessor, a synchronous square wave generator, a sine-wave generator, an arithmetic unit, a bi-phase SPWM5, a controllable inverter, a filter circuit, a motor and a voltage and current sensor, wherein the arithmetic unit and output square wave signals control the controllable inverter to work through the bi-phase SPWM5, so that the area of the output impulse voltage is equal to that of expected sine waves in a corresponding interval.

The invention provides a method for managing batteries of electric bicycles by using a computer. The method comprises the following specific step: recognizing identity information of every battery. Unusual conditions of charging saturability, over-fast descending of electric quantity of the batteries and the like of the batteries can be monitored, charging can be implemented by different staged charging methods, the problem of vulcanization of the insides of storage batteries which are lack of electricity deeply is eliminated, moreover, by adjustment, harmonic interference is low, flexible boosting and voltage-reduction output of output direct-current voltage can be realized, management of different types of batteries in a large range is implemented, and the service lives of the storage batteries are prolonged.

The invention provides a method for reducing coexistence interference of multiple networks and a terminal, and the method comprises the steps: obtaining a first working channel of a first network anda second working channel of a second network if the terminal employs the first network and the second network for communication at the same time; if the first working channel and the second working channel meet the harmonic interference condition and the harmonic noise of the receiving signal of the interfered network is greater than a preset threshold, adjusting a power amplifier in a signal transmitting link of the interfered network so as to reduce the harmonic noise of the receiving signal of the interfered network; wherein the interference network is the network with the minimum frequencyof the frequency band where the working channel is located in the first network and the second network, and the interfered network is the network with the maximum frequency of the frequency band where the working channel is located in the first network and the second network. According to the method, by improving the linearity of the power amplifier, the harmonic noise of an interfered network receiving signal is reduced, so that the terminal performance is improved.

The invention discloses a micro-grid island detection method and system. The method comprises the following steps that the voltage of a common connection point is collected, and the phase and frequency are obtained; whether an island phenomenon occurs is determined, if YES, the method is completed, and otherwise, a next step is followed; and a disturbance current is input, the voltage of the common connection point is collected again, whether the island phenomenon occurs is determined again, if YES, the method is completed, and otherwise, the first step is returned to. The system comprises a PWM driving module, a collection module and an island detection module, the collection module obtains the voltage, phase and frequency of the common connection point, and sends the voltage, phase and frequency to the island detection to compare the frequency and voltage of the power grid, a detection signal is sent to the PWM driving module, and thus, an inverter of a distributed power generation system is controlled, and the disturbance current waveform corresponding to output of the inverter is generated. Thus, micro-grid island detection can be realized rapidly, the validity of island detection can be still ensured under the condition of distributed energy devices, and interference of harmonic waves is reduced.