194results about How to "Improve homeostasis" patented technology

A gate drive circuit includes a turn-on side circuit for turning on a gate of a power switching device, the turn-on side circuit including a first turn-on side power supply circuit and a second turn-on side power supply circuit, the first turn-on side power supply circuit including: a first turn-on voltage source for supplying a first turn-on voltage; first turn-on wiring; and a first turn-on switch connected in the first turn-on wiring and controlled by a gate drive signal; and the second turn-on side power supply circuit including: a second turn-on voltage source for supplying a second turn-on voltage applied to the gate of the power switching device to set the power switching device in a steady (on) state; second turn-on wiring; a second turn-on switch connected in the second turn-on wiring; and a turn-on side delay circuit for delaying the gate drive signal and passing it to the second turn-on switch.

The invention discloses an automatic regulating apparatus for controller parameters of a servo driver of a motor and a method thereof. The apparatus comprises an inertia identifier, a parameter initial regulator, a parameter checker, a parameter optimizer, a parameter saving and displaying device, a speed controller, a position controller, a torque controller, a PWM (Pulse-Width Modulation) generator and a coded disc. In the invention, the servo driver of an alternating current permanent magnet motor automatically configures the parameters of the position controller and the speed controller according to different rotary inertias of mechanic load, checks and further optimizes the automatically configured parameters through the parameter checker and the parameter optimizer so that the position response and the speed response of the servo driver are relatively optimal. The servo driver of the alternating current permanent magnet synchronous motor automatically regulates the control parameters according to work occasions and achieves ideal control effect. The whole process is manual participation free and completed fully by the servo motor of the alternating current permanent magnet synchronous motor.

The invention discloses a sine wave inverter parallel system with variable current ratio, which is characterized by comprising a monitoring management unit and one or a plurality of inverter power supply modules in redundancy parallel operation; the monitoring management unit is connected with all the inverter power supply modules through a communication signal wire; the inverter power supply modules are mutually connected by the communication signal wires, synchronous signal wires and average current signal wires; and each inverter power supply module is simultaneously connected with a DC (Direct Current) input end and an AC (Alternating Current) output end. The proportion of the load current shared by each module of the parallel system provided by the invention can be set as required so as to meet the requirements on uniform load current sharing (current equalization) by parallel inverter power supply modules with same capacity or load current sharing by the inverter power supply modules with different capacities in the parallel system according to different proportions, so that the parallel function of the inverter power supply modules with different capacities is realized.

The invention discloses a bidirectional direct-current converter feedback linearized back-stepping sliding-mode control mode. The bidirectional direct-current converter feedback linearized back-stepping sliding-mode control method comprises steps of using a filtering capacitance voltage and inductive current as control variables to establish a mathematic model of a bidirectional direct-current converter, performing feedback linearization on an original state variable to form a new linearized state equation, tracking an error with a new state variable as an input of a controller, combining a back-stepping method with a sliding-mode variable structure and designing a feedback control rule of a converter system, wherein the feedback control rule of the inverter system is performed on pulse width modulation and controls the bidirectional direct-current converter. The bidirectional direct-current converter feedback linearized back-stepping sliding-mode control mode combines the feedback linearization with the back-stepping sliding mode control to apply to the bidirectional direct-current converter, solves a non-minimum phase characteristic and a variable structure characteristic of the converter, greatly reduces fluctuation of bus voltage, expands a stable area of a system and has a good engineering application prospect.

The invention relates to a control method for a photovoltaic grid-connected inverter on the basis of back-stepping sliding-mode control. The control method is technically characterized in that direct current voltage Udc of a photovoltaic side bus is collected, a mathematical model of a photovoltaic grid-connected single-phase voltage full-bridge inverter is set up, a tracking error of a control variable uac is set, a back-stepping sliding-mode control model of the photovoltaic grid-connected single-phase voltage full-bridge inverter is set up, and the single-phase photovoltaic grid-connected inverter is controlled according to the mathematical model and the back-stepping sliding-mode control model of the photovoltaic grid-connected single-phase voltage full-bridge inverter. The control method is reasonable in design, a back-stepping method and a sliding-mode control method are combined, the stable state and the dynamic property are good, and the control method is suitable for linear and non-linear loads and adapts to engineering application reality, provides a new thought for the inverter control system design and has the good engineering application prospect.

An exhaust aftertreatment device for an internal combustion engine is disclosed which contains multiple, parallel channels of a porous material, such as cordierite or silicon carbide, in which about some of the channels are plugged at an upstream end and other channels remain unplugged. In one embodiment, the substrate has an SCR coating and the engine has a urea supply system. Other embodiments include using TWC and LNT formulations. Several washcoat configurations and other specific geometries and dimensions to encourage crossflow, diffusion, and adsorption are disclosed herein.

The invention provides newly-separated Lactobacillus plantarum HEW-A490. The Lactobacillus plantarum HEW-A490 has the advantages that the Lactobacillus plantarum HEW-A490 is evident in probiotic performance and stress resistance, the probiotics prepared by the Lactobacillus plantarum HEW-A490 can fast activate and proliferate after entering the intestines of animals and can form a beneficial dominant bacterial community to maintain intestinal track balance, animal feed utilization efficiency can be increased, cost can be saved, the steady state of the digestive tract internal environments in the animals is improved, nutrition absorption is promoted, animal growth is promoted, economic benefits are increased, the Lactobacillus plantarum HEW-A490 is promising in application prospect, and the like.

The invention discloses enterococcus faecalis HEW-A131 which is high in thermal resistance, wide in acid-alkali resistance range, high in stress resistance and relatively high in probiotic property. The strain is preserved in the China General Microbiological Culture Collection Center on June 17th, 2014, the preservation serial number is CGMCC NO.9353, and the classification name is enterococcus faecalis. The enterococcus faecalis HEW-A131 has excellent microorganism characteristics, remarkable probiotic property and stress resistance and super high fermentation property, not only is the utilization efficiency of feed of animals increased, but also the cost is reduced, moreover the stability of the environment inside the alimentary canals of animals is greatly improved, the adsorption and utilization of nutrition are promoted, the animal growth is promoted, the production performance, immunity and breeding property of the animals are remarkably improved, the production cost is lowered, and the economic benefits are increased.

The invention discloses a chicken feed probiotic agent containing enterococcus faecalis and a preparation method of the chicken feed probiotic agent. The chicken feed probiotic agent is prepared by virtue of the steps of evenly mixing enterococcus faecalis HEW-A131 active bacterial sludge, bacillus subtilis active bacterial sludge, saccharomyces cerevisiae active bacterial sludge and a stabilization protective agent together in the mass ratio of (0.1-0.8): (1-2.5): (0.1-0.5): 1, and then pelletizing, drying, coating and the like; the probiotic agent is capable of improving the utilization efficiency of an animal feed and saving the cost, and also capable of greatly improving the steady state of the internal environment of the digestive tract in an animal body, promoting the absorption and utilization of nutrition and promoting the growth of the animal; as a result, the productivity, the immune performance and the reproductive performance of the animal are obviously improved, the production cost is reduced and the economic benefit is increased.

The invention belongs to the technical field of droop control of DC converters, relates to a droop control method of a DC converter with a function of secondary adjustment of adaptive impedance, and aims to solve the problems that distributed generating unit cable impedance difference causes poor droop current homogenization effect to the DC distributed power supply system and the DC micro grid based on droop control and the parallel DC converters is low in steady state and dynamic current homogenization precision. The method has the advantages that the steady state and dynamic current homogenization precision of the parallel DC converters in the distributed DC power supply system and the DC micro grid based on droop control is improved; parameters, such as voltage, current and droop coefficient, of the parallel converters are transmitted in real time through low-speed communication, the droop coefficient is adjusted in self-controllers of the parallel converters, and finally external characteristic impedances of the parallel converters are equalized; droop curves are subjected to shifting adjustment, and bus voltage drop caused by droop control is improved.

This invention relates to a 2-way DC convertor by phase shift of voltage regulation at one end and current stabilizing at the other plus PWM control and a control method, in which the 2-way DC converter includes a primary circuit, a switch control and a close-ring control, the primary circuit is composed of inductor L1, a switch tube S1 and serial branch 1, inductor L2, switch tube S2 and serial branch2, two auxiliary switch tubes Sa1 and Sa2, a clamp capacitor Cc and a composite branch 3, switch tubes S3 and S4 and serial branch 4, bleeder capacitor Ca and Cb, a serial branch 5 and an isolation transformer, the switch control circuit is composed of a phase shift control chip, a monostable trigger8 and a PWM control chip 9, the close ring control part is made up of a phase shift angle close ring control loop and a duty ratio close ring control loop, characterizing that: 1, suppressing the voltage peak of the tube, 2, reducing the circumfluence loss of the converter to guarantee the soft switch in the total load sphere, 3, the uncoupling control of the phase shift angle and the duty ratio realizes 2-way free flow of energies.

The invention discloses an active noise reduction headphone based on an active noise control algorithm, a noise reduction method and a storage medium. The method comprises the following steps: acquiring headphone outside noise by a reference microphone, and transmitting the acquired outside noise to all active noise control systems; processing the outside noise acquired by the reference microphoneby the active noise control systems by virtue of a variable order algorithm of combining a variable iteration parameter and a qualified function, and outputting cancellation noise to a silencing speaker; and outputting the received cancellation noise by the silencing speaker and canceling the actual noise. According to the novel active noise reduction headphone based on the active noise control algorithm provided by the invention, with the adoption of a robust design, the noise signal is subjected to cyclic iterative processing by the system, the most suitable noise reduction system parameters can be selected, and the change of a noise signal is rapidly and accurately tracked, so that the noise reduction effect is greatly improved.

The invention discloses a maximal power point tracking (MPPT) control method for a single-phase single-stage photovoltaic inverter. The method comprises the steps of: sampling output current and output voltage of a photovoltaic cell, calculating output power of the photovoltaic cell; respectively filtering direct current components of the output voltage and the output power through high-pass filtering to obtain alternating current components of the output voltage and the output power; regarding the alternating current component of the output voltage as disturbance quantity of optimizing control of an extreme value, multiplying the disturbance quantity by the alternating current component of the output power, and then obtaining estimated work voltage of the maximal power output point by low-pass filtering and integration, superposing the disturbance quantity on the estimated work voltage, and repeatedly carrying out the steps to ensure that the photovoltaic cell works near the maximal power output point all the time. According to the maximal power point tracking control method for the single-phase single-stage photovoltaic inverter disclosed by the invention, the inherent quality of the system is sufficiently utilized without additionally injecting a disturbance signal, and the effect of the external disturbance signal on the system is eliminated. In addition, the maximal power point tracking control method for the single-phase single-stage photovoltaic inverter can ensure less calculation of the MPPT control method, thereby facilitating implementation.

The invention discloses a least square method-based extended Kalman filter rotating speed estimation method of an asynchronous motor. The method is specifically implemented according to the following steps of (1) solving a fading factor by use of a least square method, obtaining an optimized fading factor determining algorithm, adaptively adjusting an estimation error in real time and quickly tracking a state change; (2) introducing the fading factor into a state prediction covariance matrix of a traditional extended Kalman filter, building a strong tracking extended kalman filter, adjusting a gain matrix online in real time and compelling output residual sequences to be kept mutually orthogonal; and (3) building the least square method-based strong tracking extended kalman filter digitization system under an alpha-beta shaft system of an induction motor and carrying out rotating speed estimation. By the rotating speed estimation method disclosed by the invention, the adaptability of a system model on an actual system and an external environment change is improved; the steady accuracy and the gross error resistance of the system are improved and the system is faster in convergence in a disturbance.

The invention discloses a Buck-Boost converter variable damping passive control method based on a port controlled dissipation Hamiltonian model. The method comprises the following steps of 1, according to the system state averaging model and the state variables of a Buck-Boost converter, converting the system state averaging model of the Buck-Boost converter into a port controlled dissipation Hamiltonian model form, and verifying the passivity of the port controlled dissipation Hamiltonian model form; 2, according to the port controlled dissipation Hamiltonian model of the Buck-Boost converterand an interconnection and damping distribution passive control method, giving an expected interconnection and damping matrix and carrying out passive controller design; 3, designing a second-order differential tracker according to the influence of the damping coefficient change of the given damping matrix on the system performance, and realizing the real-time change of the injection damping; 4,designing a variable-damping passive controller according to the passive controller and the second-order differential tracker, and controlling the output voltage of the Buck-Boost converter. Accordingto the invention, by means of the control method, the output voltage of the Buck-Boost converter can be quickly converged to the expected output voltage. The steady-state error of the output voltageis reduced, and the overall performance of the system is improved.

The invention discloses a network access current control method for a single-phase less container load (LCL) filtering grid-connected inverter and belongs to the field of network access current control of a grid-connected inverter. The method comprises the following steps of: feeding back six voltage and current variables which are easily measured in a single-phase LCL filter to obtain 18 feedbacks through proportion, integration and differential, and selecting a proper feedback combination to configure a characteristic equation of an LCL filter grid-connected inverter system transfer function from a third order to a fourth order so as to guarantee that four poles of the configured characteristic equation can be freely configured; further configuring a fourth-order characteristic equationin a form that two poles serve as conjugate poles at fundamental frequency and two poles serve as conjugate poles at resonant frequency; and finally, comparing to acquire various feedback coefficients in the selected feedback combination. By the method, the high gain of a system open loop transfer function on a forward path is achieved, a resonance peak at a natural resonant frequency is effectively suppressed, and the system has good steady state and dynamic responses.

The invention discloses a magnetic isolation drive circuit comprising an isolation drive transformer, a first capacitor C1, a second capacitor C2, a discharge MOS pipe and a discharge MOS pipe drive circuit, wherein the isolation drive transformer is used for transmitting an isolation drive signal; the first capacitor C1 is connected with the input side of the isolation drive transformer in series; the second capacitor C2 is connected with the output side of the isolation drive transformer in series; the discharge MOS pipe is connected with the output end of the magnetic isolation drive circuit in parallel; the discharge MOS pipe drive circuit is connected to a grid electrode of the discharge MOS pipe; and a series loop is formed by an output side winding of the isolation drive transformer, the second capacitor C2 and the discharge MOS pipe. The magnetic isolation drive circuit has simple structure and low cost and can effectively increase the stability of a power supply which works in a stable state and a transient state.

The invention discloses a model prediction current control method of a permanent magnet synchronous motor. The method comprises the following steps: obtaining a d-axis current disturbance item and a q-axis current disturbance item; obtaining three-phase current, three-phase line voltage and rotating speed signals of a permanent magnet synchronous motor, and obtaining a d-axis current observation value, a q-axis current observation value, a d-axis current disturbance item observation value and a q-axis current disturbance item observation value by utilizing a linear expansion state observer; obtaining a d-axis output value and a q-axis output value of a disturbance controller, obtaining an inductance prediction value by using an inductance extraction algorithm, and obtaining a d-axis current prediction value and a q-axis prediction current value in combination with an incremental prediction model; and adjusting the switching signal of the permanent magnet synchronous motor by using theinductance prediction value, the d-axis current prediction value and the q-axis prediction current value so as to realize the closed-loop control of the permanent magnet synchronous motor, so that therobustness of a permanent magnet synchronous motor model prediction current control algorithm is improved.

The invention discloses an unbalanced power adaptive optimization allocation method for a multi-end linear system. The method employs a dual-layer control structure comprising a primary sag control layer and a power rebalance optimization layer. The power rebalance optimization layer aims at the unbalance power caused by the frequent fluctuation of a load or new energy, and an equivalent cost expression of a system additional power generation cost caused by the power rebalance is deduced based on a multi-end flexible DC polar coordinate equivalent model comprising a voltage source converter station, a radial multi-end flexible DC common DC reference voltage is introduced, and a novel active power-DC voltage sag curve is designed. The proposed method irons out the defects that the conventional optimization control strongly depends on the high-speed communication and a centralized processing layer. The method can enable the white balance power to be adaptively and economically allocatedunder the normal condition, enables the additional power generation cost of a system to be remarkably reduced, still can maintain the DC voltage stability and power balance under the fault condition,and is remarkable in control effect.