66results about How to "Avoid Oscillating Phenomena" patented technology

The invention provides an expansion valve opening controlling method for preventing the oscillating of an expansion valve, which aims at solving the problem of valve oscillating caused by the factors that the regulating steps of the valve are fluctuated and a system is controlled misorderly due to the lagging influence of the system in existing expansion valve opening control. The expansion valve opening controlling method comprises the following steps of: S1. setting target superheat degree and standard valve opening; S2. initiating the valve, setting the valve opening as the standard opening after a compressor is started; S3. judging whether the starting time of the compressor achieves t1, and if yes, executing the S4; S4. determining the practical superheat degree of the valve after t1; S5. determining the superheat degree SH, controlling and regulating the valve opening of the expansion valve according to the difference delta SH between the current superheat degree SH and the superheat degree SH' at the last moment; S6. regulating the step number of the valve to be 1 or minus 1 after the compressor continuously runs for a certain time t (t is larger than t1) and within the time t2 after the absolute SH is equal to 0 and retreating is carried out; and S7. after the time t2, returning the S4. With the expansion valve opening controlling method, the valve oscillating phenomenon due to improper valve regulating steps can be avoided, and the system can safely and reliably run.

The invention is suitable to the field of electrical switches and switch power-supplies, and provides an insulation driving circuit of a power switch tube. According to the invention, on the basis of the insulation driving circuit of the traditional power switch tube, the reliability and stability of the insulation driving circuit in conduction and disconnection are improved through increasing the gate filter capacitance of the power switch tube and correspondingly accelerating disconnection of a discharge path; the acceleration for the disconnection of the discharge path works when the gate filter capacitance is greater, the gate filter capacitance is subjected to rapid discharge when in disconnection, and the switch oscillation phenomenon of MOSFET (metal-oxide-semiconductor field effect transistor) caused by slow decrease of a gate voltage is avoided; when the gate filter capacitance is greater, the gate voltage is very stable, which is very good for the MOSFET; and when an input signal is at a close state, through accelerating the disconnection of the discharge path, a gate of the MOSEFT is discharged all along, thus the gate voltage cannot be accumulated, and the error conduction of the power switch tube which is required to be turned off is avoided.

The invention discloses a high-stability laser pumping source with an overtemperature protection function and belongs to the technical field electronic equipment. The laser pumping source structurally comprises a laser module (1), a power control module (2) and a temperature control module (3). The laser pumping source is characterized by further comprising a display driving module (3) structurally, and the power control module (2) is composed of a power setting module (21), a power sampling module (22), a PID operation module (23), an LD driving module (24), an overtemperature processing module (25) and a soft starting module (26). The laser pumping source is high in stability and has the functions of overtemperature alarming power-off and soft starting.

The invention relates to a method of forecasting transient temperature field by using S-shaped variable stepwise during slab band hot rolling process, and the time step mathematical model of the S-shaped variable stepwise is: Delta t equals to a-b*exp(-c*t). By using the S-shaped variable stepwise to carry out transient temperature field finite element solving, not only calculating precision is improved and the design requirement of primary temperature field is satisfied, but also calculating time is greatly shortened. The method solves the problems of low calculation precision and slow speed and improves calculating efficiency when solving the transient temperature field by using finite element method.

The invention relates to a method of solving collected heat capacity matrix during rolling process by using finite element, and carries out calculation by totaling elements at the same line or row with the heat capacity matrix in finite element linear equations instead of diagonal elements. The invention effectively overcomes the oscillating phenomenon produced by adopting a traditional finite element method to calculate the transient temperature field, and ensures the calculation stability. Approved by the comparison of an armor plate surface temperature value with an actually measured temperature result during medium and thick plates rolling process by using the method, the method ensures having higher calculation precession when calculating the transient temperature field.

The invention discloses a permanent magnet bearing squeeze film dumper with an elastic ring, which comprises a bearing outer ring, a bearing inner ring fixedly sleeved on a shaft system, and a lubricating oil cavity filled with lubricating oil, as well as the elastic ring, wherein the bearing outer ring is mounted in the lubricating oil cavity; the bearing inner ring and the bearing outer ring are radially magnetized, resulting in that the opposite surfaces of the both are like in poles; a gap is reserved between the bearing inner ring and the bearing outer ring; and the inner ring of the elastic ring is propped against the outer ring of the bearing outer ring, while the outer ring of the elastic ring is propped against the lubricating oil cavity. The permanent magnet bearing squeeze film dumper can improve radial bearing rigidity, provides larger damping ability, and is compact in structure.

The invention relates to a direct type soil source heat pump system, which belongs to the technical field of refrigeration and heat pump. The system is composed of a compressor, a gas-liquid separator, an oil separator, a four-way change-over valve, a cooling agent / water heat exchanger, a bi-directional different working medium heat filling expansion valve, a device for drying and filtering, a level glass, a liquid separating device, an air collecting pipe, parallel branch of an outer fin copper pipe buried heat exchanger, an one-way valve, a solenoid-controlled valve and the like. The bi-directional different working medium heat filling expansion valve is used for throttle, liquid separating is accomplished to liquid cooling agent after gas-liquid separation when heat-production is in progress, and the buried heat exchanger employs compact outer ribbed structure and can operate heat-production and refrigeration. The direct type soil source heat pump system has the advantages of reliability, high efficient and environment protection.

The invention relates to a fractional Fourier transform realizing method based on multi-sampling, belongs to the field of signal processing and can be used for improving the calculation efficiency realized in real time. The method decomposes the original arithmetic into two parallel multi-phase equivalent structures by adopting a multi-sampling signal processing principle based on a discrete sampling arithmetic, thus removing redundant operations, optimizing the arithmetic flows and solves the problems of slow speed, large time lag and not being not beneficial to real time processing of an Ozaktas discrete sampling arithmetic to realize real time calculation; compared with the original arithmetic, the flow calculation load is smaller and the efficiency is higher; besides, the parallel structures are more suitable for the appearance of hardware; moreover, an more effective window-adding semi-band filter is selected at the part of inputting the interpolation filter of the pre-treatment of a sequence, thus not only solving the edge oscillation problem occurred during low orders, but also being beneficial to pipeline processing and improving the calculation efficiency when realizing as the length of the filter is shorter.

The invention relates to a distributed refrigeration control system for a storage refrigeration house and a control method of the distributed refrigeration control system. The distributed refrigeration control system comprises a microcontroller, a sensor, an input display screen, heating power expansion valves, a water regulating valve, a high and low pressure control valve, a compressor, a condenser, evaporators and a liquid accumulator, wherein the microcontroller is connected with the sensor, the input display screen, the heating power expansion valves, the water regulating valve and the high and low pressure control valve respectively; the high and low pressure control valve is connected with the compressor; the water regulating valve is connected with the condenser; the heating power expansion valves are connected with the evaporators; the evaporators are connected with the liquid accumulator; the method comprises the steps of training the neural network, collecting parameters, inputting data, outputting data and the like; through the adoption of the system and the method, the control mode and control process can be automatically regulated according to the application purposes and application environment of the control system.

The invention discloses a crane inching control method and system. The method includes that when a hydraulic motor starts, a pressure sensor, arranged on a pressure measuring port of the hydraulic motor, periodically sends a hydraulic motor pressure value measured in real time to a pressure comparer at a first time interval; the pressure comparer calculates difference between an instantaneous pressure value before last stop of the hydraulic motor and the currently received hydraulic motor pressure value; a PID (proportion integration differentiation) controller calculates a current increase slope value according to the received difference; a current control unit generates gradually-increasing control current by the aid of the current increase slope value and a preset control current value, and provides the generated control current to the hydraulic pump. Inching control is performed from the perspective of compensating leakage of a whole hydraulic control circuit, and the hydraulic motor is prevented from impact, shaking or gliding and the like.

The invention relates to an intelligent drawer type reactive compensation device with compensation function and a special shipping car thereof, belonging to the field of power reactive compensation, capable of realizing independent protection and control of each compensation unit group and conveniently pushing main compensation single compensation drawer and a compensation single compensation drawer into a compensation cabinet or drawing the main compensation single compensation drawer and compensation single compensation drawer out from the compensation cabinet for maintenance. The invention has the key points that: multiple main compensation single compensation drawer cases and multiple compensation single compensation drawer cases are all sequentially arranged at corresponding positions in the compensation cabinet in a drawable way, and multiple main compensation single compensation drawer cases and multiple compensation single compensation cases can be conveniently drawn out from the compensation cabinet or pushed to the corresponding positions in the compensation cabinet by virtue of the drawer rail. A movable rail frame is arranged on a shipping frame by virtue of a rail suspension mechanism, the movable rail frame can slide up and down along the shipping frame, and a rail frame height regulating mechanism is arranged below the movable rail frame. The invention is applicable to distribution automation implementation and modification of various power grids.

The problem to be solved by the present invention is to uniformly condition an air-conditioned room by having warm air or cold air to reaching every corner of the air-conditioned room. The solution of the present invention is that in a wall-mounted air conditioner, an air-conditioner body 1 with an air flow discharge port comprising air flow orienting plate means 23. The air flow orienting plate means comprises upper side horizontal air gate plates 25A and 25B and a lower side horizontal air gate plate 24, wherein the upper side horizontal air gate plates 25A and 25B are arranged in an upper longitudinal axis direction within the air discharge port, while the single piece of horizontal air gate plate 24 is arranged to extend in a lower longitudinal axis direction. The upper side horizontal air gate plates 25A and 25B are allowed to rotate in opposite directions within an arbitrary range of longitudinal arrangement, while the lower side horizontal air gate plate 24 is allowed to rotate within a range smaller than the rotation range of the upper side air gate plates.

The invention discloses VSC alternating current fault ride-through method and device of an extra-high voltage hybrid multi-terminal direct current system. The method comprises the following steps: determining whether a receiving end VSC has an alternating current fault or not according to an alternating current voltage of the receiving end VSC, and generating a fault signal and enabling an alternating current low-voltage current limiting link, a direct current modulation link and a positive and negative sequence current control link of the receiving end VSC with the fault when the receiving end VSC has the alternating current fault; sending the fault signal to a rectifier station and a non-fault inverter station, controlling the rectifier station to enter a DC voltage control mode, and controlling the non-fault inverter station to perform short-time power increasing operation; after the alternating current fault is removed, the faulted receiving end VSC is recovered to the normal working state, and a fault removing signal is generated; sending the fault clearing signal to a rectifier station and a non-fault inverter station, and recovering the rectifier station and the non-fault inverter station to a normal working state so as to recover the direct-current power of the extra-high voltage hybrid multi-terminal direct-current system; the method can improve the ride-through and recovery characteristics when an AC fault occurs at the inversion side, and improves the operation safety of the system.

The invention belongs to the technical field of unmanned system cooperative formation, and discloses a heterogeneous unmanned system cooperative formation control system suitable for severe sea conditions, wherein the system comprises a shore-based system, an unmanned aerial vehicle system and an unmanned ship system; the shore-based system is used for planning an initial path; the unmanned aerialvehicle system is used for updating a secondary optimization path of an unmanned aerial vehicle in real time according to the initial path and adjusting the unmanned aerial vehicle model in real time, so that the unmanned aerial vehicle flies as much as possible according to the secondary optimization path of the unmanned aerial vehicle and keeps stable; and the unmanned ship system is used for updating the secondary optimization path of the unmanned ship in real time according to the initial path and adjusting the unmanned ship model in real time, so that an unmanned ship sails according tothe secondary optimization path of the unmanned ship as much as possible and keeps stable.

The invention provides an adaptive non-singular fast terminal sliding mode observer control method, and belongs to the field of motor torque control. The adaptive non-singular fast terminal sliding mode observer control method comprises the steps that the coefficients of the exponential reaching law in terminal attractors and the terminal attraction reaching law are adjusted adaptively through thetorque difference value, and the overall reaching rate is adjusted through the torque difference value change rate; a sliding mode hyperplane is determined through the stator current and voltage, andthe sliding mode hyperplane is adjusted adaptively through the torque difference value and the torque difference value change rate; the sliding mode control rate is obtained through the hyperplane and the reaching law, and the control rate is adjusted adaptively through the torque difference value and the torque difference value change rate; and real-time torque is calculated and obtained througha torque calculation module, and a torque difference value is generated by the real-time torque and the given torque. According to the adaptive non-singular fast terminal sliding mode observer control method, the terminal attractor reaching law, the control rate and the hyperplane are adjusted adaptively, the overshoot and oscillation phenomena of a sliding mode system during controlling switching are avoided, meanwhile, the quite good adaptive effect on parameter perturbation and external interference is achieved, and the stability performance of a brushless direct current motor control system is improved.

The invention relates to a constant voltage control and constant current control seamlessly switching method in a charging power source and a device thereof. A switching combination control unit is added in the control of the charging power source, the switching combination control unit comprises a voltage and current detecting module, a weighting coefficient control module, a memory module and a switching combination calculation module. The current charging state is judged by the weighting coefficient control module according to the numerical values of current voltage and current detected by the voltage and current detecting module, the weighting coefficient of the voltage and the current is calculated to obtain a switching combination result, and the switching combination result is used for producing driving pulse which is used for driving a power switch element of the charging power source. The proportion of the voltage and the current in the switching combination result is controlled by controlling the numerical value of the weighting coefficient, the change between the constant voltage and the constant current is slow, the smooth seamless transition of the switching process can be realized, and the oscillating phenomenon can be completely avoided so as to guarantee the stability of the charging process.

The invention provides a high stability laser generating circuit based on PID control, belonging to the electronic equipment technical field. The high stability laser generating circuit comprises a laser module (1), a power control module (2) and a temperature control module (3), and is characterized in that the power control module (2) is composed of a power setting module (21), a power sampling module (22), a PID calculation module (23), an LD driving module (24) and an overtemperature power off module (25). The high stability laser generating circuit has high stability, and is provided with an overtemperature power off function.

The invention discloses a low-rank tensor completion method for alpha-order total variation constraint of a damaged video, and the method is implemented according to the following steps: reading in a damaged video file with a high loss rate by utilizing MATLAB, processing the damaged video file into a three-dimensional tensor, expanding the three-dimensional tensor into a two-dimensional matrix along each module, performing regularization processing on boundaries of the matrixes, and obtaining a two-dimensional matrix of a zero Dirichlit boundary condition; defining a target functional about tensor completion of the damaged video, wherein the target functional comprises an alpha-order total variation regular constraint term and a low-rank constraint term, and the alpha-order total variation regular constraint term and the low-rank constraint term are not independent of each other; introducing three auxiliary matrixes for the boundary-regularized two-dimensional matrix, decoupling and optimizing a target functional through an augmented Lagrange formula, solving the optimized target functional, and finally obtaining a complemented three-dimensional video tensor through continuous iteration; and combining a fractional order TV regularization term in a fractional order bounded variation space with low-rank constraint to carry out tensor repair, so global information can be recovered, and lost fine details can also be recovered.

The invention discloses an active control method and system for improving the AGC control performance of a wind power plant, and the method comprises the steps: making the most of wind turbines with ahigh adjustment speed according to the difference of the active power control response time of different wind turbines, repeatedly and quickly tracking the active power instruction value of a grid-connected point, and shortening the AGC response time; when the active power fluctuation of the wind turbine generator with the AGC function quitting leads to that the active variable quantity of the grid-connected point exceeds a dead zone, immediately redistributing to reduce the distribution interval time. Different distribution reference values are adopted according to different active power distribution triggering conditions, and the phenomena that the distribution result is too large or too small and oscillation occurs in the adjusting process due to the fact that the active power reference values, participating in calculation, of the grid-connected point and the wind turbine generator are inaccurate are avoided. By compensating the active power output error of the wind turbine generator, the deviation between the active power distribution value and the actual value of the wind turbine generator is reduced, and the AGC regulation precision of the wind power plant is improved.

The invention provides a system for preventing generation of oscillation at time of closing of a power tube of an LDO. The system comprises a control circuit, wherein the control circuit performs individual closing control on the power tube after receiving a closing enable signal; and the control circuit automatically detects grid voltage of the power tube, and slowly discharges until the grid voltage of the power tube rises to power voltage. According to the control circuit provided by the invention, the grid voltage of the power tube can be raised individually per stages, so that the currentof the power tube is not zero instantly, the resonance caused by the fact that the output current is instantly reduced to zero when the output of the LDO circuit has relatively large parasitic inductance, and thus the external LC resonance circuit has a steady state building process, and the oscillation phenomenon is avoided.