44results about How to "Suppress harmonic interference" patented technology

The invention discloses a multiple-input multiple-output antenna transmitting-receiving circuit, and the circuit comprises a radio frequency transmitter and a plurality of transmitting-receiving units. Each transmitting-receiving unit comprises an antenna, a power amplifier, a low-noise amplifier, a first switching unit, and a second switching unit. The power amplifier is used for the power amplification of a to-be-transmitted signal outputted by the radio frequency transmitter, so as to transmit the to-be-transmitted signal. The low-noise amplifiers are used for the amplification of radio frequency signals received by the antennas, so as to transmit the radio frequency signals to a radio frequency transceiver. The first switching units and the second switching units are used for switching a transmitting path according to the transmitting-receiving state of the radio frequency transceiver. The circuit is additionally provided with the switching units so as to achieve the switching of the transmitting path, thereby achieving the isolation of the transmitting path with a receiving path, effectively inhibiting harmonic interference generated between the transmitting path and the receiving path, and improving the isolation degree of adjacent antennas.

The invention relates to the field acquisition field of earth physical exploration, in particular to a multi-factor scanning method of a controllable vibroseis. The method comprises the following steps of: exciting an earthquake wave with a wide-frequency scanning signal to finish acquisition; selecting a receiving channel to make an amplitude spectrum and a frequency division scanning field; decomposing the signal to create a group of sub-scanning with different start frequency and end frequency for spectrum superposition and factor superposition and comparing the superposed spectrum with practical data to confirm a sub-scanning group; combining sub-scanning for field acquisition, carrying out the frequency division scanning of the amplitude spectrum, comparing amplitude spectrum data and frequency division records to confirm the best sub-scanning factor and mapping. The invention can reduce the correlated sidelobe of data, improve the signal-to-noise ratio of the data, effectively restrict harmonic interference, lessen the blindness of tests, improve the data quality and save exploration expenditure.

The invention discloses a method for testing the broadband characteristic of a CVT (capacitor voltage transformer) by a high voltage harmonic in the technical field of electric power. The method has the technical scheme that a high voltage harmonic source of U1 (j omega) is applied between a high voltage end of the CVT and the ground, and the voltage U2 (j omega) of each frequency point at a secondary side and the input voltage U1 (j omega) at a primary side are tested to obtain the broadband transmission characteristic of the CVT through computation. The method disclosed by the invention has the beneficial effects that components of a higher harmonic can be accurately obtained, harmonic interference can be effectively inhibited through harmonic treatment guiding measures, and the quality of electric energy is improved.

The invention relates to a digital predistortion system and method of frequency selectivity harmonic suppression. The digital predistortion system and method of frequency selectivity harmonic suppression are characterized in that a parallel binary channel predistortion unit processing framework is utilized; a main predistortion device is used to suppress in-band distortion of a power amplifier at the center frequency; an auxiliary predistortion device is used to suppress harmonic distortion of the power amplifier at the selected frequency; a predistortion parameter estimation module is used to acquire a predistortion coefficient matrix according to the output signals of the main predistortion device and the auxiliary predistortion device and sampling output of the power amplifier at the center frequency and the selected frequency; and the main predistortion device and the auxiliary predistortion device perform predistortion coefficient adjustment according to the predistortion coefficient matrix. The digital predistortion system and method of frequency selectivity harmonic suppression can only suppress the harmonic interference at the interesting target frequency point, thus being lower in the implementation complexity, compared with a multi-channel predistortion method which suppresses a plurality of harmonic waves at the same time. Besides, the digital predistortion system and method of frequency selectivity harmonic suppression perform weighing synthesis on the optimization target of the main predistortion device and the auxiliary predistortion device to form a single target function, and introduce a particle swarm algorithm, thus accelerating the convergence speed of the algorithm.

The invention provides a digital interference elimination and avoiding method in a steel passing data and energy simultaneous transmission system and an apparatus thereof. Data signal transmission accuracy can be increased. The interference elimination method comprises the following steps of at a receiving end of a data transmission link, acquiring a data signal; adjusting a weight coefficient of an adaptive filter so that an interference signal output by the adaptive filter tends to an interference signal in the data signal; and through subtracting the interference signal output by the adaptive filter from the data signal, acquiring an OFDM signal after the interference is eliminated. The interference avoiding method comprises the following steps of when symbol modulation is performed on a data transmission link sending end, inserting 0 in front of a data signal transmitted by an interfered subchannel so that the data signal is transmitted through a next normal subchannel; and before the symbol modulation is performed on the data transmission link receiving end, multiplying the data signal before the demodulation by an avoided vector, wherein the symbol modulation is not performed on the transmission data of the interfered subchannel. The method and the apparatus are suitable for the ultrasonic wave communication technology field.

The invention provides an LES dual-mode rapid power grid fundamental current amplitude detection method which comprises the following steps of S1, establishing an LES filter universal model; S2, by designing different actual sampling times N and sampling periods Ts, establishing a high-speed LES filter and a low-speed LES filter; S3, respectively feeding a certain phase of power grid voltage signal into the high-speed LES filter and the low-speed LES filter, and obtaining a high-speed LES detection value and a low-speed LES detection value; S4, obtaining an absolute value of a difference value of the high-speed and low-speed LES detection values; S5, feeding the absolute value into a hysteresis comparator, if the absolute value is greater than a hysteresis upper limit, using the high-speed LES detection value as a final value for output, and if the absolute value is smaller than a hysteresis lower limit, using the low-speed LES detection value as the final value for output. According to the dual-mode rapid power grid fundamental current amplitude detection method provided by the invention, power grid fundamental current amplitude detection time is shorter than a quarter of cycle wave, and meanwhile, effectively inhibits influence of low order harmonics on detection accuracy and promotes steady state detection accuracy.

The embodiment of the invention discloses a method and device for controlling harmonic interference. The method is applied to a dual-connection communication system, and comprises the following steps:acquiring a first harmonic interference signal causing harmonic interference to a downlink signal of a second connection belonging to dual connection from a first uplink signal of the first connection belonging to the dual connection transmitted by a transmitter; adjusting the first harmonic interference signal to a target amplitude and a target phase; and superposing the adjusted first harmonicinterference signal with a received signal received by the receiver to control a second harmonic interference signal generated by the transmission of the first uplink signal in the received signal, the received signal comprising the downlink signal and the second harmonic interference signal. The method and device provided by the embodiment of the invention are low in complexity, do not increase the size of the terminal equipment, and can effectively control harmonic interference.

The invention relates to an array antenna second harmonic interference field modeling and calculating method which includes steps of feeding for each array element of an array antenna through a voltage source; setting excitation amplitude and phase of each array element; calculating the excitation amplitude and the phase of each array element during transmission of the array antenna second harmonic according to non-linear response of amplifiers; splitting the surface of each array element triangularly and splitting a feeder linearly so as to acquire geometrical information of the surface of each array element and the feeder; and calculating induction current of the surface of each array element and the feeder according to the excitation amplitude and the phase of each array element during transmission of the array antenna second harmonic and the geometrical information of the surface of each array element and the feeder. By the array antenna second harmonic interference field modeling and calculating method, an interference field at interfered equipment during transmission of the array antenna second harmonic is acquired accurately, and then coupling level of a receiving end of the interfered equipment is acquired, so that support for suppressing and analyzing harmonic interference and improving interference resistance performance of sensitive equipment is offered.

The invention discloses a control pulse modulation method, device and equipment and a storage medium, and relates to a lowest level approximation modulation module, a space vector pulse width modulation module and a plurality of MMC sub-modules. The method comprises the steps of receiving a to-be-modulated signal, and generating a first driving signal through the lowest level approximation modulation module; receiving the to-be-modulated signal and a preset triangular carrier signal, and generating a second driving signal through a space vector pulse width modulation module; collecting a firstdriving signal or a second driving signal according to the real-time conduction number of modulation sub-modules of the lowest level approximation modulation module, and generating a pulse control signal; determining a control sequence of the plurality of MMC sub-modules according to the pulse control signal; based on the pulse control signals and the control sequence, generating and outputting control pulses of the MMC sub-modules. Thus, the voltage waveform can be flexibly and accurately controlled under the condition that the voltage change range is large, and meanwhile harmonic interference is restrained.

The invention discloses an ultrahigh frequency high image rejection filter, which comprises an amplifier, a double-tuning tracking filter, a mixer and a surface acoustic filter and is characterized in that the double-tuning tracking filter is provided with a sixth capacitor, one end of the sixth capacitor is connected with a pre-stage circuit, and the other end of the sixth capacitor is connected with a front end of a first capacitor. A rear end of the first capacitor is connected with an outer end of a first inductor, an inner end of the first inductor is connected with inner ends of a second inductor and a third inductor, and inner ends of three inductors are connected with a positive pole of an alternating direct current power supply. An outer end of the third inductor is connected with the capacitor in series to be connected with the ground, and an outer end of the second inductor is connected with a second capacitor in series to be connected with a post-stage circuit. The ultrahigh frequency high image rejection filter has the advantages of not only effectively rejecting image frequency and harmonic interference in an ultrahigh frequency range, but also reducing insertion loss to some extent, and increasing useful signal gain.

The present invention proposes a multi-magnetic circuit phase-shifting transformer, which includes an input part, a transformer part, a rectifier part and an output part. The middle iron cores are arranged in groups of two. Each group is equipped with an input winding and at least one output winding. A side yoke iron core is also arranged beside the core, and the output winding includes an upper tap, a lower tap and at least one middle tap, and the current phase shift is realized by the wiring mode of each tap of the output winding. The magnetic circuit is formed between the iron cores of each phase and the adjacent iron cores in the present invention, which minimizes magnetic flux leakage and can suppress DC bias and harmonic interference in the transformer circuit. At the same time, the wiring mode of each tap of the output winding realizes The adjustment of the current phase realizes the simple design and adjustment of the current phase.

The invention relates to a hydrogen energy power generation system based on filtering of an output filter, which mainly utilizes low-pass filtering function of the output filter (1) to filter the high-frequency harmonic component in rectifier-level voltage so as to provide approximately constant direct current (DC) voltage to a load. The whole hydrogen energy power generation system comprises main components including a polymer hydrogen energy fuel cell (11), an alternating current (AC)-DC circuit (8), a DC-DC circuit (9), a storage battery (6), an intelligent storage battery monitoring module (SBMS) (4), a DC-AC converter (2), a DC-DC converter (3) and a filter (1). The whole hydrogen energy power generation system is capable of effectively reducing harmonic and commutation nicks of a main power supply, and protecting power electronic components of a driving device from the damage caused by the impact of peak current of the main power supply.

The invention relates to a three-level high-voltage high-power water-cooled frequency converter system, which comprises a water-cooled filter cabinet, an expandable bridge arm parallel frequency converter cabinet, a full digital regulating cabinet, a water-cooled excitation winding system cabinet and a water circulation heat dissipation system cabinet. The water-cooled filter cabinet, the expandable bridge arm parallel frequency converter cabinet, the full digital regulating cabinet, the water-cooled excitation winding system cabinet, and the water circulation heat dissipation system cabinet are mutually assembled from left to right to form a complete high-voltage high-power water-cooled frequency converter system. The water-cooled filter cabinet reduces input high-order harmonics for smoothing filtering and suppresses the harmonic disturbance caused by ultra-long-distance input in a parallel system of bridge legs. The water-cooled excitation winding system cabinet realizes single/double sets of three-phase 6-pulse silicon controlled rectifier excitation winding system functions through different assembly modes of a silicon controlled rectifier module. The scheme of the invention can effectively suppress the harmonic interference caused by the ultra-long-distance input of the parallel system of bridge legs, balance the input current of the bridge leg parallel frequency converter, effectively improve the space utilization, and further provide a more stable operation condition for a frequency converter based on a double-leg power unit system.