17results about How to "Reduce Harmonic Pollution" patented technology

The invention discloses a control method and system for a network-forming type energy storage converter, and relates to the technical field of power electronics, and the method comprises the following steps: obtaining sampling signals of voltage and current at the network side of a converter circuit, extracting three-phase voltage and three-phase current, executing network-side power control, and calculating network-side reference voltage and reference angular frequency; converting a modulation signal under a direct current coordinate system into a modulation signal under a static coordinate system based on coordinate system conversion of voltage and current numerical values, and converting the modulation signal into a trigger signal of a switch tube based on a signal modulation algorithm; and obtaining the direct current side current of the converter circuit, executing double-current cooperative control by introducing the reference current, and calculating the phase shift angle between the primary side voltage and the secondary side voltage of the high-frequency transformer. By acquiring the grid-side sampling signal and calculating the reference quantity, it is ensured that the output of the converter and the power grid are kept synchronous, power transmission is optimized, harmonic pollution is reduced, and efficient inversion control is achieved.

This invention discloses a phase-shifted full-bridge plasma power supply based on all SiC devices, belonging to the field of special power supply technology. It includes: a rectifier unit with a power factor correction circuit; an inverter unit containing a phase-shifted full-bridge topology composed of SiC power devices and an energy storage inductor, achieving zero-voltage switching through phase-shift control; a transformer unit; an output unit including an output filter capacitor; and a control unit that uses an incremental PID algorithm to generate phase-shift control signals. This invention analyzes the differences in zero-voltage switching between the leading and lagging bridge arms, utilizes the low output capacitance characteristics and dynamic dead-time adjustment of SiC devices, broadens the soft-switching range under light loads, effectively reduces output current ripple, and improves dynamic response speed and overall efficiency.

The invention provides a power factor correction circuit adaptive control method and system, and the method comprises the steps: collecting an input voltage signal of a power factor correction circuit, obtaining a voltage control signal of the power factor correction circuit, and collecting a current sampling signal of the power factor correction circuit; the duty ratio of a switch driving signal is calculated based on the current sampling signal, the input voltage signal and the voltage control signal, the current sampling signal and the duty ratio are in a reverse growth relation, the input voltage signal and the duty ratio are in a reverse growth relation, and the current sampling signal and the input voltage signal are in a reverse growth relation. The voltage control signal and the duty ratio are in a homodromous growth relationship; and controlling the on-off of a switching device of the power factor correction circuit according to the duty ratio of the switching driving signal. According to the invention, the switch driving signal of the power factor correction circuit is adaptively adjusted based on the load change and the input voltage change, and the stable operation of the driven equipment is ensured.

The present invention provides a three-phase current type rectifier power supply control method and system for hydrogen production by electrolysis of water, and relates to the field of power supply control. The method comprises: sectorizing a three-phase input voltage signal to obtain an initial even sector signal and an initial odd sector signal; calculating the number of carrier cycles in the initial even sector signal and the number of carrier cycles in the initial odd sector signal to determine a target carrier frequency; determining an even sector extension time based on the target carrier frequency to generate a target even sector signal and a target odd sector signal, thereby generating a triangular carrier signal; generating a switch drive signal of a three-phase current type rectifier power supply based on the triangular carrier signal and a modulation wave obtained based on the three-phase input voltage signal, and having the advantages of eliminating the distortion of the input current of the three-phase current type rectifier power supply at the sector switching point, reducing the harmonic content of the input current, reducing the output current ripple, and improving the efficiency of the rectifier power supply.

The invention relates to the technical field of Vienna rectifiers, in particular to a control method for improving harmonic power grid input adaptability of a Vienna rectifier, which comprises the following steps of: performing coordinate transformation on acquired three-phase power grid voltage and input current to obtain voltage and current signals under a fundamental wave rotating coordinate system, extracting a fundamental wave current error signal, and calculating the harmonic power grid input adaptability of the Vienna rectifier; the method comprises the following steps: acquiring a current error component of each harmonic, converting the current error component into a rotating coordinate system corresponding to each specified harmonic to obtain the current error component of each harmonic, and in each harmonic rotating coordinate system, independently controlling the current error component of the corresponding harmonic by adopting a proportional-integral controller to generate a control voltage component of each harmonic; inversely transforming the control voltage component of each harmonic to a fundamental wave rotating coordinate system, and superposing to form a total harmonic compensation voltage; according to the invention, by adopting the control method of combining the self-adaptive loop parameters with the bus lifting strategy, the adaptability of the input current of the rectifier along with the power grid voltage under the harmonic power grid voltage is enhanced, so that the problem of overcurrent of the rectifier under different working conditions is avoided.

The invention discloses a four-quadrant operation washing machine variable frequency driver which comprises a full-bridge booster circuit composed of a PFC power switch tube and a bus capacitor, the full-bridge booster circuit is further connected with an alternating current input voltage source, a high-frequency PFC inductor, a current sampling resistor, a motor driving power switch tube and a controlled motor equivalent model, and the full-bridge booster circuit, the high-frequency PFC inductor, the current sampling resistor, the motor driving power switch tube and the controlled motor equivalent model jointly form a complete circuit. Through the arrangement of the full-bridge booster circuit composed of the four PFC power switch tubes and the bus capacitor, a traditional diode rectifier bridge circuit is replaced, bidirectional flow of energy is successfully achieved, that is, the energy is fed back from the power grid side to the controlled motor equivalent model and from the controlled motor equivalent model to the power grid side, energy waste is avoided, and the energy efficiency is improved. Due to the fact that the washing machine can maintain a high speed reduction rate under the condition that the loss probability of electronic devices is not additionally increased, the operation efficiency of the washing machine is greatly improved, the structural design is exquisite and efficient, and the washing machine has great application prospects.

The invention provides a dynamic voltage control method and system for an energy storage converter, and relates to the technical field of data processing, and the method comprises the steps: carrying out the mathematical modeling of a circuit of the energy storage converter, and building the representation of a voltage in a two-phase rotating coordinate system; according to the expression of the voltage in the two-phase rotating coordinate system, a voltage signal output by the energy storage converter is filtered through a filter, and a filtered voltage signal is obtained; and modulating the filtered voltage signal, and generating a modulation waveform by calculating and distributing the duty ratio of each phase switch so as to control the output voltage of the energy storage converter. Through mathematical modeling, filtering processing, modulation control and an optimization algorithm for simulating the bacterial foraging process, accurate and real-time control of the output voltage is realized, and the response speed and the stability of the system are improved.

The present invention relates to the field of distribution station monitoring technology, and specifically discloses an online monitoring system and method for distribution station based on big data, the method comprising: a power quality assessment module, a power balance analysis module, a distribution station intelligent scheduling module and a distribution station database. The present invention reduces harmonic pollution by evaluating and analyzing harmonics in the power system, ensures the stability and reliability of power supply, timely discovers and protects electrical equipment, extends its service life, and effectively reduces grid losses, thereby ensuring the safe and stable operation of the power system. At the same time, the distribution station is adjusted through the intelligent scheduling indicators of the distribution station, reducing the volatility and uncertainty of new energy power generation, ensuring the stable operation of the power grid, and helping to smooth the power generation fluctuations of new energy through the energy storage system, improving the utilization efficiency of electric energy, and providing auxiliary services when needed, thereby enhancing the flexibility and reliability of the power grid.

The present invention discloses a decoupling control method for a weak power grid inverter system. In a weak power grid, due to the characteristics of a resistor network, active power and reactive power are highly coupled. Considering the inherent coupling characteristics of the entire distribution network, by changing the controller parameters and the grid strength, the active power and reactive power of the weak distribution network can be effectively decoupled, solving the impact of the high impedance ratio in the weak distribution network. At the same time, a fuzzy neural network FNN is introduced, and the fuzzy neural network is trained using historical data to learn and model the complex nonlinear relationship of the power system. Combining fuzzy logic and fuzzy neural networks, the network can process fuzzy and uncertain information, and has adaptability and generalization capabilities. The controller dynamically adjusts the system parameters according to the real-time collected data and the output of the fuzzy neural network to achieve decoupling control and optimal distribution of power. It provides a more robust and adaptive solution for the next generation of distribution networks with high penetration.

The invention relates to the field of AC motors, and particularly provides a brushless doubly-fed AC motor and a design method thereof, and the method comprises the steps: configuring the winding proportion of a high-voltage winding and a low-voltage winding in the brushless doubly-fed AC motor in advance; connecting the high-voltage winding with a power grid, and supplying power to the low-voltage winding through low-voltage frequency conversion; constructing a motor constant magnetic flux model, a motor constant power factor model and a motor efficiency control model according to the winding proportion; determining a first control strategy of the rotor side current according to the motor constant magnetic flux model; according to a motor constant power factor model, stator side and rotor side synchronous current phases are determined, and a second control strategy under a constant power factor is constructed; and loading the first control strategy and the second control strategy into a motor efficiency control model, determining a topological equation under the maximum power efficiency, and determining design parameters according to the topological equation.

The present invention relates to the field of photovoltaic power generation technology, and in particular to a distributed photovoltaic system grid-connected control method and system. The method comprises the following steps: obtaining historical multi-source heterogeneous data, including historical power output data, historical meteorological data, battery aging data and array parameter data; extracting multimodal environmental features from the historical multi-source heterogeneous data, and capturing the long-term dependency of the time series based on a bidirectional LSTM network to obtain a LSTM modeling result sequence; using 5G edge computing technology and FPGA acceleration technology to determine the MPPT setting value, reactive compensation ratio, and anti-islanding control parameters of the inverter according to the multimodal power curve data to obtain distributed control strategy data. The present invention realizes dynamic optimization of the MPPT strategy through dual alternating reinforcement learning.

The invention provides a circuit for driving a three-phase motor. The circuit comprises a rectifier bridge module arranged on a circuit substrate, a Boost-PFC module, a three-phase inversion module and a driving module, wherein the Boost-PFC module, the three-phase inversion module and the driving module are integrated on the same DBC substrate. And the DBC substrate is electrically connected to the side surface of the circuit substrate by adopting the same pair of pin groups. The AC input end of the rectifier bridge module is connected with commercial power. The direct current input end of the Boost-PFC module is connected with the direct current output end of the rectifier bridge module. A direct current input end of the three-phase inversion module is connected with a direct current output end of the Boost-PFC module, and three alternating current output ends of the three-phase inversion module are respectively connected with corresponding power supply access ends of the three-phase motor; the power supply access end of the driving module is connected with a first independent power supply. The signal detection end of the driving module is connected with the signal output end of the Boost-PFC module, and the modulation signal output end of the driving module is connected with the modulation signal input end of the Boost-PFC module. Compared with the prior art, the circuit provided by the invention can stably drive the three-phase motor on the premise of meeting the requirements of heat dissipation and high integration level.

The application belongs to the technical field of power electronics, and discloses an optimal carrier modulation method and system considering oscillation and unbalanced midpoint voltage. The method obtains normalized sinusoidal waves of phase A, phase B and phase C according to a three-phase normalization formula of a SPWM modulation strategy of a three-level Vienna rectifier; calculates a modulation signal correction variable and an unbalanced coefficient of a midpoint voltage; calculates a zero sequence voltage u z.ICB considering oscillation and unbalanced midpoint voltage, and injects the zero sequence voltage into the three-phase normalized sinusoidal waves to obtain intermittent modulation waves of the three-level Vienna rectifier of phase A, phase B and phase C considering oscillation and unbalanced midpoint voltage. The application can greatly reduce switching loss and improve the efficiency of the converter under the working condition of oscillation and unbalanced midpoint voltage, and can suppress low-frequency harmonics and eliminate current zero-crossing distortion. The application does not need sector judgment and only needs to inject a zero sequence component, and is simple and convenient to implement.

This application provides a driving circuit and related equipment. The driving circuit includes a Vienna circuit, an MCU, and a step-down circuit. The first signal output terminal of the MCU is connected to the control terminal of the Vienna circuit, and the second signal output terminal is connected to the control terminal of the step-down circuit. The input terminal of the Vienna circuit is connected to a three-phase AC power supply, and its output terminal is connected to both the input terminal of the step-down circuit and the compressor via a DC bus. The output terminal of the step-down circuit is connected to a fan. The MCU sends a first control signal to the Vienna circuit to control its voltage conversion process, and simultaneously sends a second control signal to the step-down circuit to control its step-down processing of the input DC voltage, ultimately realizing the adaptation of the three-phase AC power supply to the compressor and the fan.

The invention relates to the technical field of plant illumination, and discloses a plant growth full-spectrum LED intelligent driving and dimming system which comprises a full-spectrum LED array module, a driving module, a control module, a sensing module and a feedback regulation and control module. The full-spectrum LED array module comprises five kinds of LED lamp beads and covers the ultraviolet A wave band and the spectral ranges of blue light, red light, far-red light and white light. And the driving module adopts a two-stage structure of a front-stage active PFC circuit and a rear-stage half-bridge LLC resonant converter. According to the plant growth full-spectrum LED intelligent driving and dimming system, a full-spectrum LED array module is optimized through an MATLAB exhaustion method to complete non-uniform layout, an illuminance sensor of a sensing module collects illumination data in a 100 ms period, a feedback regulation and control module calls a light uniformizing control algorithm to be combined with a Lambert formula and an improved Portrait equation to establish a precise mathematical model, and the precise mathematical model is used for driving the full-spectrum LED array module to conduct dimming on the full-spectrum LED array module. The double-closed-loop inner ring adjusts the PWM duty ratio of each LED branch in real time according to the PWM duty ratio, rapidly compensates illumination difference, and thoroughly solves the problem that the center is bright and the periphery is dark.

The utility model discloses a special high-performance four-quadrant frequency converter for the electromagnetic industry, which belongs to the technical field of power electronics, and comprises a main topology part and a control part, the main topology part comprises an input filtering part, a rectification filtering part and an inversion part, the input filtering part comprises a network side inductor L1, a filtering capacitor C1 and a machine side inductor L2, and the rectification filtering part comprises a three-phase half-bridge insulated gate bipolar transistor module, a first bus capacitor Cd1, a second bus capacitor Cd2, a first voltage-sharing resistor Rd1, a second voltage-sharing resistor Rd2 and a buffer loop. The inversion part comprises one or three paths of three-phase half-bridge insulated gate bipolar transistor modules, and the control part comprises a power supply board, a detection board, a rectification side main control board, an inversion side main control board, a rectification side driving board, an inversion side driving board and a driving board.

The invention discloses an SRM harmonic closed-loop torque ripple suppression method based on current square. The method comprises the following steps: (1) constructing an electromagnetic torque expression containing current square, and solving a current square harmonic model with optimal torque ripple; (2) obtaining a current square model with an optimal current square direct current bias value and an optimal torque ripple; (3) generating a fundamental wave amplitude reference value of the current square model with the optimal torque ripple, and obtaining a current square excitation model in an actual injection motor and an actual current square model of an output motor; (4) in order to realize closed-loop suppression of the torque ripple, the auxiliary channel executes a correction process; and (5) compensating an instantaneous torque peak appearing in a specific electrical angle range, completing harmonic closed-loop torque ripple suppression, and realizing an optimal torque ripple scheme. According to the invention, a double-layer compensation architecture based on current square harmonic injection and torque real-time feedback is constructed, so that the systematic suppression of the torque ripple of the switched reluctance motor is realized.