711results about How to "Improve dynamic response performance" patented technology

The invention relates to a multifunctional digitized welding machine, which comprises a full-bridge type inversion main circuit, a control circuit and a soft switch PWM (Pulse-Width Modulation) driving circuit, wherein the full-bridge type inversion main circuit is composed of an IGBT (Insulated Gate Bipolar Translator); the soft switch PWM driving circuit of a symmetric carrier is based on a CPLD (Complex Programmable Logic Device) or FPGA (Field Programmable Gate Array); the inversion main circuit comprises a rectifying filtering module, an IGBT full-bridge inversion module, a main transformer and a secondary rectifying filtering module; the control circuit comprises a DSP (Digital Signal Processor) control processor, a manual idle-dropping circuit, a regulating, detecting and sampling circuit for a feedback current and voltage signal outputted by the welding machine, a collecting and setting circuit for a feeding speed and given voltage of the welding machine, a display circuit for an interface and parameter of an external keyboard and a communication circuit connected to a PC (Personal Computer); the regulating, detecting and sampling circuit for the feedback current and voltage signal outputted by the welding machine comprises a Hall voltage sensor for detecting a feedback arc voltage outputted by the welding machine and a Hall current sensor for detecting an output current of the welding machine; and the collecting and setting circuit for the feeding speed and given voltage of the welding machine comprises a collecting circuit for a given voltage and given current, namely the feeding speed, on a panel of a feeder.

The invention discloses a linear servo motor control method for numerically-controlled machine tool driving. According to the method, a sine wave linear motor is controlled through a feedback signal detection module, a position control ring, a speed control ring and a current control ring, and the feedback signal detection module comprises a position detection module, a speed detection module and a current detection module, wherein the position control ring adopts a composite control method combining PI (proportional-integral) feedback control and neural network given compensation control, the speed control ring adopts a fuzzy controller with a disturbance observer, and the current control ring adopts a space vector PWM (pulse-width modulation) technology with a PI regulator. The linear servo motor control method has the advantages that the neural network compensation PI control technology, the fuzzy control and the alternating current motor vector control are combined, and the anti-jamming capability, the dynamic response capability and the system stable state precision of a linear servo motor are improved.

The invention relates to a rotor of a high-quality and high-speed built-in permanent magnet motor and a magnetic steel structural parameter determining method thereof. In the invention, the whole section magnetic steel of each electrode of the rotor of a conventional built-in permanent magnet motor is divided into multiple sections of magnetic steel which have the same polarity and different widths; the multiple sections of the magnetic steel are respectively arranged in a rotor core; and reinforcing ribs with the function of magnetic isolation are arranged among the multiple sections of the magnetic steel. By reasonably modulating and determining the width and distribution of each section of the magnetic steel, the air gap magnetic density waveform approaches sine distribution; harmonic components are reduced to the greatest extent; the eddy current loss of the magnetic steel and the torque pulsation of the motor are simultaneously reduced; and the electromagnetic performance of the motor is enhanced. Furthermore, the multiple sections of the magnetic steel are arranged in the circumference along the rotor; the highest rotating speed of the safe operation of the rotor is greatly enhanced on machinery; the radial thickness which is needed by the magnetic circuit of the rotor is obviously reduced on the structure; the rotational inertia and weight of the rotor are reduced; the dynamic response of the motor is improved; and the requirements of a high-speed driving system on the performance of the motor are met.

The invention discloses a one-dimensional rotation and two-dimensional inclination working platform, which comprises a pedestal, a bottom layer board, a middle layer board, an upper layer board, an adjusting mechanism and a driving part. The bottom layer board and the upper layer board achieve the inclination of the working platform in a mutually orthogonal direction respectively, while the middle layer board achieves the rotation of the working platform in a larger range in a plane vertical to the two orthogonal directions. The pedestal is connected with the bottom layer board through a rotating pair, a wedged slide block and a spring, a linear guide way is fixed on a bottom plate, and the wedged slide block supports the bottom layer board; the bottom layer board is connected with the middle layer board through a cambered guide way and a central rotating shaft; and the middle layer board is also connected with the upper layer board through the rotating pair, the wedged slide block and the spring, the linear guide way is fixed on the middle layer board, and the wedged slide block supports the upper layer board. The adjusting mechanism comprises a coarse adjusting structure and a fine adjusting structure. The invention can achieve the work demands of the one-dimensional rotation and the two-dimensional inclination for the working platform, and can achieve the angle positioning of a sub-angle second-time level in a larger space adjusting range.

The invention relates to a networked layered compensation method for voltage unbalance of a PCC (Point of Common Coupling) of an islanded microgrid. The method comprises the following steps: (1), establishing a networked layered control system structure; (2), performing real-time detection, and converting all the electrical quantities into an alpha-beta coordinate system; (3), obtaining positive and negative sequence components of voltage or current; (4), computing the positive sequence active power and positive sequence reactive power at the PCC; (5), obtaining an output reference voltage and a reference angular frequency; (6), obtaining the input of a reference occurrence module; (7), obtaining the reference voltage at an alpha-beta stationary coordinate system; (8) sending the voltage v<abc> at the PCC to a secondary controller; (9), obtaining positive and negative sequence components; (10), obtaining UCR<alpha beta>; (11), feeding back the UCR<alpha beta> to a primary controller of each DG (Distributed Generator); (12), figuring out v<V alpha beta>; (13), calculating the reference value of a current control loop; (14), obtaining the switching drive pulse of an inverter; (15) driving switching tubes of a three-phase full bridge inversion circuit to switch on or off by the switching drive pulse, and controlling the inverter to output rated sine-wave voltage. According to the invention, the voltage at the PCC can be subjected to global compensation, and the reactive power distribution precision is improved.

The invention discloses an aquiculture pond dissolved oxygen control system comprising a data acquisition and transmission layer and a data storage and sharing layer, which communicate with each other in a wireless way. By studying the characteristics of nonlinearity, greater inertia, long time delay and time-variation of dissolved oxygen change in an aquiculture pond and the difficult problem that a larger culture area is hard to control, and according to the invention, an aquatic product pond dissolved oxygen control system based on a wireless sensor network is designed, comprises the data acquisition and transmission layer and the data storage and sharing layer and forms a wireless sensor network monitoring system for detecting, intelligently controlling and managing dissolved oxygen in the culture pond.

The invention discloses a sliding-mode variable structure control method of a single phase grid-connected inverter based on a multi-resonant sliding mode surface. The method comprises the steps of: firstly, building a linear sliding mode surface according to detected current i1 of an inverter side filter inductor of the single phase grid-connected inverter, the voltage vc of a filter capacitor, the current i2 of a network side filter inductor, and the target output current i1* of a grid-connected inverter system, the target voltage vC* of the filter capacitor and the grid-connected target current i2*; adding a resonant item into the linear sliding mode surface so as to obtain the multi-resonant sliding mode surface; designing a sliding-mode variable structure controller by the multi-resonant sliding mode surface, leading a linear state feedback controller to an original nonlinear controller to obtain a final control quantity modulation wave d(s), and finally comparing the modulation wave with a carrier wave to generate a driving signal for driving a switch tube to act. According to the control method disclosed by the invention, the robustness and dynamic response ability of the grid-connected inverter system are improved; the tracking accuracy of grid-connected current is also improved; the harmonic content is removed, and the control method is simple and easy to achieve.

The invention relates to a self-adaption quasi-PRD control method for a photovoltaic grid-connected inverter. The self-adaption quasi-PRD control method for the photovoltaic grid-connected inverter relates to the technical field of photovoltaic grid-connected inverter control, and aims to solve the problems that the existing photovoltaic grid-connected inverter has poor adaptability on power grid impedance change, and the stability of a photovoltaic grid-connected system is poor in a weak current grid. The method comprises the following steps of injecting disturbance current with specific frequency into a power grid through a disturbance current injection method; then obtaining a relational expression of current controller parameters and power grid impedance based on the principle of closed loop pole parameter configuration; when the power grid impedance Rg and power grid inductance Lg are changed, realizing self-adapting adjustment on controller parameters Kp, Kr and Kd so as to adapt to the ever-changing power grid impedance, so that the adaptability and the stability of the photovoltaic grid-connected inverter control system are improved. The self-adaption quasi-PRD control method for the photovoltaic grid-connected inverter can be used for controlling the photovoltaic grid-connected inverter.

The invention is an embedded digital control inverter power source used in tube and plate overall position automatic welding, which comprises a main circuit, a control circuit and a high frequency arc-ignition circuit. The main circuit comprises a rectifying wave filter module, a high frequency inverter module, a power voltage-transforming module and a rectifying smooth module which are connected sequentially. The rectifying wave filter module is connected with a three-phase alternating current (AC) input power, and the rectifying smooth module is connected with a load. The control circuit includes an over-voltage and under-voltage protective testing module, a voltage and current sample testing and feedback module, an ARM microprocessor and a high frequency drive module. The over-voltage and under-voltage protective testing module is respectively connected with the three-phase AC input power and the ARM microprocessor. The voltage and current sample testing and feedback module is respectively connected with the ARM microprocessor and the load. The ARM microprocessor is also connected with the high frequency drive module and the high frequency arc-ignition circuit. The high frequency drive module is also connected with the high frequency inverter module, and the high frequency arc-ignition circuit is also connected with the load. The invention can realize the overall digital control of the tube and plate automatic welding inverter power source.

The invention discloses a general loop current control method for a modular multi-level converter considering low frequency oscillation. The general loop current control method is mainly used for restraining a low frequency oscillation loop current and a second harmonic generation loop current in a bridge arm loop current of the modular multi-level converter. The relation between a bridge arm voltage and the bridge arm loop current is analyzed to obtain the oscillation frequency of the low frequency oscillation loop current of the converter so as to provide beneficial evidence for the design of a control system; the cut-off frequency of a low pass filter is set according to the calculated value of the oscillation frequency; the bridge arm loop current passes through the low pass filter to obtain a direct current component, and then the direct current component is subtracted by the bridge arm loop current to obtain an alternating component of the bridge arm loop current; the alternating component contains a harmonic component of the low frequency oscillation loop current and a harmonic component of the second harmonic generation loop current; the alternating component passes through a regulator to obtain a control reference voltage of the bridge arm loop current, and the control reference voltage is added to a modulating signal. By means of the general loop current control method, a low frequency oscillation component and a second harmonic generation component in the bridge arm loop current are simultaneously restrained, the loop current control system is simplified, split-phase control over the loop currents is realized, loss of the converter is lowered, and the dynamic stability of the system is enhanced.

The invention relates to the technical field of engineering machinery, and discloses a load-sensitive hydraulic system, a power matching control method, device and system and an engineering machine. The load-sensitive hydraulic system, the power matching control method, device and system and the engineering machine are used for improving the control conformance, the dynamic responsiveness and the stability of the load-sensitive hydraulic system and the control performance of power matching. The load-sensitive hydraulic system comprises a variable pump assembly, a main control valve set, an actuator, an overflow valve and a flow control valve set. An oil inlet of the main control valve set is communicated with an oil outlet of the variable pump assembly, and a load-sensitive feedback oil path is arranged between a control oil port of the main control valve set and a control oil port of the variable pump assembly. Two oil ports of the actuator are communicated with two working oil ports of the main control valve set respectively. An inlet oil path of the overflow valve is communicated with the load-sensitive feedback oil path, and a switch valve is arranged on the inlet oil path of the overflow valve. An inlet oil path of the flow control valve is communicated with the load-sensitive feedback oil path, and the flow control valve comprises a proportional throttle valve and a first pressure-compensated valve arranged on an inlet oil path of the proportional throttle valve.

The present invention provides a demodulation method for the optical distance variation of an optical fibre interferometer sensor, including steps of (1) detecting the spectrum of the optical fiber interferometer sensor; (2) transmitting the detected spectrum to a computer for a Fourier transformation or Z spectrum conversion to obtain an amplitude spectrum and a phase spectrum of an optical fiber interferometer sensor reflected signal; (3) obtaining an approx center frequency of the optical fiber interferometer sensor from the amplitude spectrum and then fixing the frequency point to monitor the change of the point phase; obtaining the optical distance change of the optical fiber interferometer sensor by the phase spectrum. By monitoring the phase change around the center frequency point in the phase spectrum after the optical spectrum and the frequency spectrum conversion of the optical fiber interferometer sensor, it is capable of obtaining the optical distance change of the interferometer sensor, comparing with the traditional detection of the change of the intensity frequency spectrum center frequency, the sensor center frequency point of the phase spectrum is more sensitive to the optical distance difference, thus the invention has a high sensitivity or resolution.

Provided is a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function. For the dynamic system of a four-rotor aircraft, an integralsliding mode obstacle Lyapunov function is selected, and a four-rotor aircraft output-limited backstepping control method based on the integral sliding mode obstacle Lyapunov function is designed. Theintegral sliding mode obstacle Lyapunov function is designed in order to ensure that the output of the system is limited within a certain range, avoid too large overshoot and reduce the time of arrival. Therefore, the dynamic response performance of the four-rotor aircraft system is improved. The invention provides a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function, which enables the system to have a good dynamic response process.

The invention discloses an oil-immersed transformer hot spot temperature evaluation method based on multi-parameter fusion. The oil-immersed transformer hot spot temperature evaluation method includes the following steps of (1) according to the process of heat transfer inside the transformer, clarifying the definition and calculation method of the hot spot heat source and hot oil area of the transformer, and reducing the calculation bias caused by taking the overall winding as the hot spot heat source; (2) correcting the algorithm of the hot oil area thermal capacitance Cwo and the hot spot thermal capacitance Chs, and improving the accuracy of the time constant tau wo and the winding time constant tau hs and the dynamic response capability of the calculation model; and (3) establishing the dynamic calculation equation of hot spot temperature by considering the influence of time-varying ambient temperature and time-varying load on the hot spot temperature. When the dynamic equation of the model is deduced, the temperature characteristics of the load loss and oil viscosity are further considered, and the calculation result can more accurately reflect the temperature rise inside the transformer. The method can dynamically reflect the characteristics of the temperature change inside the transformer, and the calculation is simple and the accuracy is high.

The invention provides an intelligent dimming driver for networking-type high-power packaged LEDs, which comprises a power adjusting system and a digital control system, wherein the power adjusting system is formed by sequentially connecting a single-phase rectifying filtering module, a resonant soft switch inverting module and a transforming and rectifying module which are switched in a single-phase alternating current input power; and the digital control system is formed by connecting an abnormity detection protection module, a sampling detection module, an ARM micro-processor system, a high-frequency driving module, a parameter setting module and a serial bus communication module mutually. The intelligent dimming driver for the networking-type high-power packaged LEDs can automatically match constant current, constant voltage and variable property driving output according to the working property of the high-power packaged LEDs so as to realize remote networking and intelligent dimming.

The invention discloses a supercharged diesel engine EGR (Exhaust Gas Recirculation) system intelligent cooling device, comprising an EGR mixer (3), a mechanical water pump (4), an electric control fan (5), a radiator (6), a thermolator (11), an EGR cooler (13), an electric control EGR valve (14), an engine ECU (Electronic Control Unit) (18), a temperature sensor (19), an exhaust gas intercooler (8) and an electric control two-position three-way valve (12), wherein an inlet of the electric control two-position three-way valve (12) is communicated with a gas outlet of the EGR cooler (13); outlets in two ends of the electric control two-position three-way valve (12) are respectively communicated with an exhaust gas inlet of the EGR mixer (3) and a gas inlet of the exhaust gas intercooler (8); a gas outlet of the exhaust gas intercooler (8) is communicated with the exhaust gas inlet of the EGR mixer (3); the electric control EGR valve (14), the electric control fan (5), the temperature sensor (19) and the electric control two-position three-way valve (12) are respectively connected with the engine ECU (18) electrically.

The invention relates to a comprehensive method for harmonizing and controlling a supercritical monotube boiler, comprising the steps as follows: 1) logic configuration of a traditional harmonizing and controlling system is carried out, the differential signal of the practical load given value is added in main control circuit of the boiler of the traditional harmonizing and controlling system, and interfaces are preserved for an increment-typed state observer, an inertia suppressor and a heat value observer; 2) the logic configuration of the increment-typed state observer is carried out and the output thereof is led into the traditional harmonizing and controlling system so as to be used as a feedforward signal for controlling the combustion rate; 3) the logic configuration of the inertia suppressor is carried out and the output thereof is led into the traditional harmonizing and controlling system so as to be used as the feedforward signal for controlling the combustion rate; 4) the logic configuration of the water-supply increment-typed state observer is carried out and the output thereof is led into the traditional harmonizing and controlling system so as to be used as a feedforward signal for controlling the water-supply; 5) the heat value observer is added in the heat value calculation circuit of the traditional harmonizing and controlling system, thus leading the heating-value signal of the quantity of the coal entering the boiler to be corrected. The method obtains excellent control effect during the controlling to the supercritical monotube boiler.

The invention discloses a closed-loop control method for battery full-range charging. The method is based on an open-loop circuit of a wireless power transmission system. The open-loop circuit of the wireless power transmission system comprises a direct-current power supply, an inverter, a primary-secondary resonant network, and a rectifier, wherein the direct-current power supply, the inverter, the primary-secondary resonant network, the rectifier and a battery are connected in sequence. The method comprises the following steps: which stage the battery is in is judged, wherein the charging stages of the battery include a constant-current charging stage, a constant-power charging stage, and a constant-voltage charging stage; when the battery is in the constant-current charging stage, the inverter is controlled in a fixed-frequency phase shift control method; when the battery is in the constant-power charging stage, the inverter is controlled in the fixed-frequency phase shift control method; and when the battery is in the constant-voltage charging stage, the inverter is controlled in a frequency-hopping phase shift control method. Through the method, full-range efficient battery charging is realized. The system is of high safety and stability.

The invention discloses a variable pitch control method of a wind generating set. The method includes the steps: acquiring real-time rotating speed of a wind wheel and real-time pitch angles of bladesof the wind generating set; calculating variable pitch speed of the blades by a proportional differential control algorithm according to the real-time rotating speed and the real-time pitch angles; controlling variable pitch rotation of the blades according to the variable pitch speed. Compared with a traditional proportional integral control algorithm, the pitch angles cannot be converted into the variable pitch speed, the variable pitch speed is directly acquired, so that delay and indeterminacy increased by a converting link are avoided, tracking of a system is accelerated, the dynamic response capability of a variable pitch system of the wind generating set is improved, the method solves the problem of excessive speed of the wind generating set under gale and strong turbulence, so that generation of an extreme load is avoided, fatigue damage to the wind generating set is reduced, and availability and the generating capacity of the wind generating set are improved.

The invention provides a direct-set torque and rotational inertia simulating system and a control method thereof. The control method comprises providing the driving torque of the measurement input shaft of a torque sensor and collecting driving torque signals, computing the target torque of a load motor through a bench controller according to set load torque and set rotational inertia and the driving torque signals, sending load motor target torque instructions to a motor direct torque controller, and receiving the load motor target torque instructions and controlling the load motor to output corresponding torque through the motor direct torque controller. According to direct-set torque and rotational inertia simulating system and the control method thereof, by taking the torque as the controlled target, influence of acceleration computing errors on control precision can be avoided; adjusting control parameters according to different bench controllers can be omitted, and usage simplicity and dynamic responsiveness can be obtained; redundancy monitoring for the operation status of the bench controller can be achieved, so that the reliability of a bench can be enhanced.

The invention provides an on-line joint servo system parameter identification and controller parameter optimization method. The method comprises the following steps: under the condition of unknown load torque, identifying load rotational inertia and damping coefficients online simultaneously based on a discrete model reference adaptive algorithm; and optimizing parameters of a speed controller according to the identified load rotational inertia. According to the technical scheme provided in the invention, rotational inertia and the damping coefficients can be identified online simultaneously, and the parameters of the speed controller are optimized according to the identification results, and dynamic response performance of the speed is improved.

The invention discloses a double DSP embedded type welding process visual feedback control system for welding seam tracking and welding quality control in welding automation, comprising a DSP image processing module, a DSP feedback control module, a power and reset module, a visual interface module, an analog video coding module and a USB control module. The DSP image processing module extracts the eigenvalues of a welding region image transmitted from the video interface module and transmits to the DSP feedback control module, the DSP feedback control module outputs corresponding signals according to the eigenvalues, and finishes close-loop control of welding seam tracking and welding quality. By this invention, welding seam tracking and welding seam shaping control can be carried out without a host computer.