57results about How to "Resolve volatility" patented technology

The invention belongs to the field of power converter control and relates to a model prediction control method of a voltage source type rectifier when a network voltage is unbalanced. The model prediction control method of the voltage source type rectifier when the network voltage is unbalanced comprises the steps of converting three-phase network voltage and a three-phase current into network voltage and a current which are under a two-phase static coordinate system through an abc / alpha beta coordinate, obtaining network positive sequence voltage and negative sequence voltage by carrying positive and negative sequence component separation of the network voltage under the two-phase static coordinate system, calculating reference values of active power, calculating current reference values of the rectifier under the two-phase static coordinate system, and carrying out model prediction current control and selecting an optimal on-off state. The model prediction control method of the voltage source type rectifier when the network voltage is unbalanced is capable of quickly and precisely tracing the current under the two-phase static coordinate and effectively eliminating fluctuation of direct current side voltage at the same time, power quality of the system is improved, a reliable network-connected operation of the rectifier when transient state network voltage is unbalance is achieved, and dynamics and stability of the whole system are improved.

The invention discloses a control method for the heating operation of an inverter air conditioner by an electronic expansion valve. When an inverter split air conditioner performs heating, the electronic expansion valve is subjected to opening control according to the exhaust and suction superheat of a compressor, and the exhaust superheat of the compressor cannot be deviated due to the influence of the length of a connecting pipeline between an indoor unit and an outdoor unit, so that the problem of fluctuation of the electronic expansion valve in the inverter air conditioner with a longer connecting pipeline between the indoor unit and the outdoor unit in the adjusting process during heating can be solved. The exhaust temperature of the compressor is controlled, so the exhaust temperature of the compressor cannot be overhigh, the compressor is ensured to normally run, and the air conditioner system can normally run.

The invention discloses a high-temperature molten salt electriochemistry testing system applicable to a temperature range of 750 DEG C - 900 DEG C; the high-temperature molten salt electriochemistry testing system comprises a high-temperature electric resistance furnace, high-temperature electriochemistry electrodes and a high-temperature molten salt crucible. A high-temperature molten salt reference electrode (2) is mainly composed of a first electrode stem (24) and a sleeve; the first electrode stem (24) is packaged in a first aluminum oxide sleeve (25) sealed by cement (27); a high-temperature molten salt working electrode (3) is mainly composed of a second electrode stem and a sleeve; the main body of the second electrode stem is packaged in a second aluminum oxide sleeve (32) including sealing cement, thus ensuring heat insulation and uniform distribution of heat under the condition of high temperature; a crucible cover (64) which is provided with a central hole (65) and made of ceramic is placed at the top of the crucible (6); the crucible cover (64) can effectively prevent electrolyte from volatilizing due to melting in high temperature, and thereby the furnace body of the electric resistance furnace is prevented from being eroded by volatilization of the molten electrolyte.

The embodiment of the invention provides a control method and system of a permanent magnet synchronous motor, and belongs to the control field of the permanent magnet synchronous motor. The control method of the permanent magnet synchronous motor comprises the following steps: determining an assumed angle of a rotor of the permanent magnet synchronous motor about an assumed rotational coordinate system at the first time of the starting stage, wherein the constancyof the specific value of the voltage vector amplitude, which is corresponding to the single current loop input,relative to the rotation speed of the rotor is maintained at the starting stage; acquiring the actual angle of the rotor about the actual rotational coordinate system at the first time; computing the first angle difference value between the assumed angle and the actual angle, and judging whether the first angle difference value is in the angle difference threshold range; and judging whether the first duration time of the angle difference value in the angle difference threshold range is greater than the time threshold; if the first duration time is greater than the time threshold, switching the permanent synchronous motor to a closed loop control state. Therefore, the closed loop switching stability of the motor is improved.

The invention provides a nonlinear-fitting infrared non-uniform correction method based on time-domain Kalman filtering correction. The technical proposal is as follows: firstly, assuming that a response change curve of each array unit of an infrared focal plane detector is continuous on time, and using a high-order multi-parameter nonlinear polynomial to fit and describe the response change curve; secondly, acquiring a response output value of each array unit at four different temperature points, using a nonlinear equation solution method to determine a plurality of parameters in each array unit response expression; thirdly, using time-domain Kalmn filtering to carry out time-shift correction on each parameter in the response expression for solving a problem that the detector response shifts with the time, and acquiring an analysis expression of the response curves of the detector array unit; and finally, using the analysis expression to calculate the response output of each array unit of the detector under any time and any temperature conditions. The nonlinear-fitting infrared non-uniform correction method realizes the correction of inconsistent response of the detector and solves non-uniformity problem of the infrared image.

The invention discloses a molten salt heat storage solar thermal power generation system. The system comprises a heat collecting subsystem, a heat storage subsystem, a steam generation subsystem and a power generation subsystem connected in sequence; the heat collecting subsystem is connected with the heat storage subsystem; the heat storage subsystem is connected with the steam generation subsystem; and the steam generation subsystem is connected with the power generation subsystem. As the connecting relation of the steam generation subsystem to the heat collecting subsystem and the heat storage subsystem is improved, the power load output stability of the power generation subsystem is improved; and the power load output by the system is not changed along with the change of solar radiation, so that the load fluctuation is largely reduced, and the whole control operability of a power station is promoted.

The invention discloses a three-phase electric and electronic transformer based on a multi-level multi-module cascade structure. The three-phase electric and electronic transformer has three levels, i.e. an input level, an isolation level and an output level. An output end of an input-level power converter is connected with an input end of a high-frequency DC / AC (direct current / alternating current) link power converter; an output end of the high-frequency DC / AC link power converter is connected with the primary side of a high-frequency transformer; the secondary side of the high-frequency transformer is connected with the input end of the high-frequency DC / AC link power converter; the output end of the high-frequency DC / AC link power converter is connected with an input end of an output-level power converter; an output end of the output-level power converter is connected with an input end of an LC wave filter; and the LC wave filter is connected with a three-phase power supply network. Basic functions, such as transformation, isolation and energy transfer of the traditional electric transformer can be realized, and for the input voltage with different levels, corresponding voltage can be born only by calculating the corresponding number of input-level serial modules and serial connection according to corresponding module number.

The invention relates to a prism-free surface settlement level monitoring method, which comprises the following steps: 1) when an automatic total station is installed, selecting four regional control points; 2) respectively calculating coordinates of points to be measured in control regions by calculating coordinates of evenly dividing points of long sides and short sides; 3) obtaining the horizontal direction angle and the vertical angle of the automatic total station according to the coordinates of each point and the coordinates of a station observation point; 4) rotating the collimation axis of the automatic total station to the angle through an automotive motor, measuring the distances S from the station observation point and each grid point and the vertical angle alpha, and obtaining the height difference H between the station observation point and each grid point based on the formula H = D . tg(alpha); 5) storing the obtained data on the automatic total station and transmitting the data to an upper computer by the automatic total station through a wireless transmission module; and 6) displaying final results on a display screen after data processing of the upper computer. Compared with the prior art, the invention has the advantages that the settlement of a hard flat surface on which a round prism cannot be installed can be monitored.

The invention discloses a video mixing encoding system and a method. The video mixing coding system comprises an encoder, a memory and a player. The video mixing coding system is characterized in that the encoder, the memory and the player are mutually connected through a data network; the encoder comprises a mixing encoding system and an encoding scheme selection module; the mixing encoding module uses at least two encoding schemes to perform encoding on video data to be encoded to obtain data of at least two encoded videos; the encoding scheme selection module chooses data of one or more than one videos from the data of the encoded video data to transmit to the memory or the player; the encoding scheme comprises an encoding protocol, screen resolution and image quality; and the various encoding schemes are combined through regulating the three various parameters The video mixing coding system fully utilizes the video data flow transmission capability, enables the video stored by the memory to achieve the best effect and does not cause the loss of the video data due to the fluctuation of the data network.

The invention relates to a proportional valve output compensation circuit and a control method, belonging to a proportional valve output circuit of which the power is supplied by a storage battery on engineering machinery. The compensation circuit comprises an optical coupling circuit, a switching and converting circuit, a PWM (Pulse-Width Modulation) output circuit, a sampling circuit, an amplifying circuit, a low-pass filter and a comparison circuit, wherein the output end of the optical coupling circuit is connected with the output end of the comparison circuit and the input end of the switching and converting circuit; the output end of the switching circuit is connected with the input end of the PWM output circuit; the output end of the PWM output circuit is connected with the input end of the sampling circuit; the output end of the sampling circuit is connected with the input end of the amplifying circuit; and the output end of the amplifying circuit is connected with the output end of the low-pass filter and the input end of the comparison circuit. The invention has the advantages that the output circuit of a proportional valve coil is sampled, amplified and compared and then fed back to the output end of an optical coupler, thereby realizing current negative feedback, and the circuit is simple, reliable and easy to realize.

The invention discloses a three-phase power electronic transformer capable of balancing asymmetric load. The transformer is divided into an input level, an isolation level and an output level, output ends of input-level power converters are connected with input ends of high-frequency DC (direct current) / AC (alternating current) link power converters, output ends of the high-frequency DC / AC link power converters are connected with primary sides of high-frequency transformers, secondary sides of the high-frequency transformers are connected with the input ends of the high-frequency DC / AC link power converters, the output ends of the high-frequency DC / AC link power converters are connected with input ends of output-level power converters, and output ends of the output-level power converters are connected with input ends of LC filters which are connected with a three-phase power supply network. The three-phase power electronic transformer capable of balancing asymmetric load can realize basic functions of transformation, isolation, energy transfer and the like of conventional power transformers, and as for input voltages of different levels, the serial module number of corresponding input levels only needs to be calculated, and corresponding voltage can be borne by serial connection according to corresponding module number.

The embodiments of the invention provide a permanent magnet synchronous motor control method and a system, which belong to the field of permanent magnet synchronous motor control. The permanent magnet synchronous motor control method comprises the following steps: determining the assumed angle of the rotor of a permanent magnet synchronous motor relative to an assumed rotation coordinate system at a first time in the start stage; acquiring the actual angle of the rotor relative to an actual rotation coordinate system at the first time; calculating a first angle difference between the assumed angle and the actual angle, and judging whether the first angle difference is within an angle difference threshold range; if the first angle difference is within the angle difference threshold range, judging whether a first duration in which the first angle difference is within the angle difference threshold range is greater than a time threshold; and if the first duration is greater than the time threshold, switching the permanent magnet synchronous motor to a closed-loop control state. Thus, the stability and robustness of motor closed-loop switching-in can be improved.

The invention discloses an LED wafer test method for stabilizing spectral energy distribution. When a non-first LED unit in a first edge area of a row of LED units is measured, the integration time ofat least one preceding LED unit of the non-first LED unit is taken as a reference. When a LED unit of a second edge is measured, the integration time of the LED unit is calculated directly based on the INT value proportion of the LED unit to the LED unit in a parameter-stable middle area, so that the integration time changes continuously from the edge to the middle area during the test, the spectral energy distribution of the LED unit in the edge area is consistent with that of the LED unit in the middle area, good spectral characteristics are presented, and the fluctuation problem of the spectral energy in the measurement process in the prior art is solved.

The invention discloses a design method of a width of an effective surface of an overflow brick for controlling the average thickness of an edge plate. According to the design method, started from a width WG of a target glass substrate, a width WY of a guide board of the glass substrate and a width WE of an effective surface of an overflow brick are calculated through introduction of a correctioncoefficient, and then an manufacturing average thickness TE of an edge plate of the glass substrate is calculated; an overflow coefficient for calculating the WE is continuously adjusted, so that thefinal TE meets design requirements; namely, the thickness TE of the edge plate of the glass substrate meets the design requirements through the design of the width WY of the guide plate and the widthWE of the effective surface. Process parameters are used for calculating other parameters of the overflow brick at the same time, and the process parameters comprise a guide plate speed V, an averageedge plate flow QE and an average edge plate mass ME, so that technological requirements of manufacturing stable guide plates in a glass substrate production line can be met. Through the design method, a problem of guide plate fluctuation of the field forming is effectively solved, and then the forming thickness distribution of the glass substrate manufacturing is optimized, so that production margins are increased from design, and consistency of thickness of the edge plate of the glass substrate is guaranteed.

The invention discloses a zero-flashing low-voltage distribution system and an operation method thereof. The zero-flashing low-voltage distribution system comprises a first power supply, a second power supply, an emergency bus, a second dual-power automatic changeover switch or a solid-state changeover switch, wherein the first power supply and the second power supply are connected with two ordinary buses in a switching station respectively; one end of the emergency bus is connected with a mobile emergency power supply and the first power supply separately through a first dual-power automaticchangeover switch; the other end of the emergency bus is connected with a static energy storage uninterruptible power supply at a user side; the second dual-power automatic changeover switch or the solid-state changeover switch is in load connection with a user. The zero-flashing low-voltage distribution system and the operation method thereof have the advantages that the power supply switching operation of the dual-power automatic changeover switches at a load side under the fault is avoided, thereby solving the problem of load flashing caused by voltage sag during power supply switching, andsolving the problem of voltage fluctuation; if the static energy storage uninterruptible power supply breaks down or is not replenished by the power supplies before a battery runs out, the power supplies are switched to a right circuit for power supply, and sensitive load flashing caused by the voltage sag can occur during power supply switching.

The invention discloses an annealing furnace inside atmosphere control method which comprises the following steps of according to the historical production data of an annealing furnace under the stable working condition, analyzing to obtain a relation table of annealing furnace heating section excess air coefficients and preheating section smoke gas oxygen contents; judging whether an annealing furnace heating schedule is changed or not; and if not, monitoring the annealing furnace preheating section smoke gas oxygen content through an oxygen content analyzer, comparing with the relation table, and adjusting the annealing furnace heating section excess air coefficient. According to the annealing furnace inside atmosphere control method provided by the invention, the non-oxidation section furnace inside atmosphere fluctuation caused by the coal gas caloric value change or the coal gas pressure fluctuation is timely and effectively solved, the non-oxidation section furnace inside weaklyreducing atmosphere is ensured to run stably, and meanwhile, the coal gas is sufficiently utilized through the feedforward control on the preheating section air amount, so that the energy is saved.

The embodiment of the invention provides an inverter and an inverter topology, and aims to solve the problems of potential drift and fluctuation of the neutral point of a three-level inverter. The inverter comprises a positive direct-current bus, a negative direct-current bus, the three-level inverter, a detection circuit and a balance circuit, wherein the detection circuit is used for detecting the voltage difference between the voltage of a first direct-current bus and the neutral point, and outputting a first driving signal, a second driving signal, a third driving signal and a fourth driving signal to the balance circuit through each port of the detection circuit; and the balance circuit is used for connecting the first direct-current bus with the neutral point when the first driving signal is received through the fourth port of the balance circuit, disconnecting the first direct-current bus from the neutral point when the third driving signal is received through the fourth port of the balance circuit and the fourth driving signal is received through the fifth port of the balance circuit, and connecting another direct-current bus with the neutral point when the second driving signal is received through the fifth port of the balance circuit.

The invention provides an optimization method and system for reconstruction error compensation of a combustion field of a cement rotary kiln and a storage medium and the method comprises the steps: firstly carrying out combustion field reconstruction of the rotary kiln in a main link of cement clinker calcination by a finite element analysis method, and building a combustion field finite element model of the rotary cement kiln; secondly, proposing a rotary cement kiln combustion field reconstruction error compensation method based on a fuzzy inference system and a deep neural network by adopting a data driving thought for errors existing in rotary cement kiln combustion field reconstruction and an actual in-kiln calcination process, and constructing a reconstruction error compensation model to compensate and correct temperature errors obtained by the reconstruction model; and finally, improving the modeling precision of the reconstruction error compensation model by adopting a reconstruction error compensation model online optimization method based on a rolling optimization thought. The state of the combustion field in the kiln can be analyzed and evaluated in real time, and the problems of low efficiency and low precision in traditional simulation of the combustion field in the rotary kiln are solved through real-time correction of simulation data and actual production data.

The invention discloses a gas path system for a rotor system of a micro gas turbine. The rotor system at least comprises a gas compressor, a turbine and at least one set of air bearings, and the gas compressor, the turbine and the air bearings are coaxially arranged. The gas path system comprises a gas source gas path and a self-static pressure gas supplementing gas path, wherein the input end of the gas source gas path communicates with a gas source, and the output end of the gas source gas path communicates with a gas inlet port of the air bearings; and the input end of the self-static-pressure gas supply gas path communicates with an outlet of the gas compressor, and the output end of the self-static-pressure gas supply gas path communicates with the gas inlet port of the air bearings. The invention further discloses a micro gas turbine with the gas path system. The invention further discloses a control method for achieving self-static-pressure gas supply through the gas path system. When dynamic and static pressure working states of the air bearings of a rotor are switched, the gas compressor is introduced to serve as a supplementary gas source, self-static pressure gas supplementation is achieved, and the form fluctuation of a gas film of the air bearings at the switching moment can be balanced, so that stable switching is guaranteed, and the stability of the working state of the rotor system is kept.

The invention discloses a vacuum pressure swing adsorption system running under a stable pressure and a control process thereof. The system comprises three sets of adsorption towers, fans and vacuum pumps, each set of adsorption towers consists of two adsorption towers, and each adsorption tower circulates according to the running mode of adsorption, primary even pressure drop, secondary even pressure drop, vacuum desorption, secondary even pressure rise, primary even pressure rise and feeding. The system adopts a six-tower process, through optimal control of the process itself, two pressure equalizing is adopted in adsorption and vacuum desorption processes, and compared with the existing two-tower to five-tower process, the fluctuation range is reduced due to one more pressure equalizing, thus solving the pressure fluctuation problem of the system itself, the problems of fan outlet pressure fluctuation and vacuum pump pressure fluctuation can be solved, and the system can operate stably.

The invention provides a motor control loop power supply mode. According to the motor control loop power supply mode, a special control transformer is arranged at the wire outlet of a two-way power conversion switch inside a feed cabinet, wherein the two-way power conversion switch is connected to two power sources, one power source is the common bus of an existing motor control cabinet, the other power source is an emergency power supply device such as a diesel generator, and when the first power source stops working, the emergency power supply device can be put into service instantly to further ensure emergency power supply of type I and II motor loads. Together with a main loop, the special control transformer achieves power switch control and is always powered by one power source. Therefore, the motor control loop power supply mode is applicable to various grounding systems, effectively solves the problem of fluctuation of control power sources, ensures reliability of the power sources of the control transformer and further ensures reliability of a motor control loop power source of an entire system.

The invention discloses a control method for stable operation of a gasification device after shutdown of partial coal pipelines. The gasification device comprises a charging bucket, a weighing tank, agasification burner, an oxygen supply device, a purging device and a gasification furnace; after the shutdown of the partial pulverized coal pipelines, the control method realizes the stable controlof the gasification device by matching and maintaining a stable material flow between the pulverized coal pipelines based on pulverized coal conveying pipeline configuration. The control method bettersolves the problem that the gasification device fluctuates after the shutdown of the partial coal pipelines since the pulverized coal pipelines have failure, and provides a guarantee for the safe long-time stable operation of the gasification device.

The invention provides a method for improving an ACLR index, comprising the following steps: presetting a primary phase of a digital intermediate-frequency oscillator (NCO) in a digital frequency conversion chip; and synchronizing the NCO of each carrier wave digital frequency conversion channel again to form same phase. The invention also provides a device for improving an ACLR index. By adopting the method and the device, the invention eliminates the carrier wave error brought by aliquant control words of the NCO, solves the problem that the peak-to-average power ratio of baseband data fluctuates in each subframe, thereby further achieving the aim of improving the ACLR index; in addition, the invention can sufficiently exert the performance of a digital intermediate-frequency chip so that the digital interpolating times are not limited.

The invention relates to a frequency hopping channel selection method and device, a communication method and device and a communication system. The method comprises the following steps: acquiring transmitting power information of a plurality of first channels in a working frequency band range of a transmitting end and signal intensity attenuation information of a plurality of second channels in a working frequency band range of a receiving end; acquiring signal strength information of the plurality of channel groups according to the transmitting power information and the signal strength attenuation information; and obtaining first probability distribution according to the signal strength information, and selecting a plurality of first alternative channel groups corresponding to the signal strength information distributed in a preset probability range in the first probability distribution as a target channel group, so as to improve the fluctuation problem introduced by different gains and insertion losses of different frequency bands on hardware, and improve the accuracy of interaction. Meanwhile, the target frequency hopping group is selected in advance before communication interaction, so that the time spent on frequency hopping channel selection in the communication interaction process can be shortened, and the communication efficiency is improved.

The invention relates to the technical field of UAVs (unmanned aerial vehicles), in particular to a barometric height detection device and a UAV (unmanned aerial vehicle). The barometric height detection device is arranged on the UAV and comprises a barometric sensor, a sensor protecting cover and a guide pipe, wherein the barometric sensor is sealed in the sensor protecting cover; the barometricsensor and the sensor protecting cover are mounted on the UAV; one end of the guide pipe is communicated with the sensor protecting cover, the other end of the guide pipe penetrates out of the sensorprotecting cover and then extends upwards to be away from blades, so that an external environment where the barometric sensor is located can be effectively isolated from turbulent flow produced by blade rotating, disturbance of an unstable barometric pressure environment on the barometric sensor is avoided, and accurate detection for barometric height is guaranteed; besides, the barometric heightdetection device is simple in structure, reasonable in design, low in production cost and good in detection effect.

The invention provides a method for removing impurity silver in reduced gold powder. The method comprises the following steps of primary digestion, washing, secondary digestion and drying. According to the method, the impurity silver in the reduced gold powder is removed by adding independently prepared boiling washing liquid A and boiling washing liquid B into the reduced gold powder with relatively high silver content step by step, so that the purification of the coarse gold powder is realized, the problems of gold product fluctuation or gold powder reworking and the like caused by trace silver impurities are solved, the direct recovery rate of gold is improved, the reworking cost is reduced, and the production and operation indexes in the gold smelting process are comprehensively improved; the method can be applied to precious metal purification processes and precious metal separation processes.

The invention discloses a method for designing the effective face width of overflow bricks for controlling the average thickness of side plates. The design method starts from the target glass substrate width W G Starting from the process, the correction coefficient is introduced to calculate the width W of the glass substrate lead plate Y and overflow brick effective face width W E , and then calculate the average side plate thickness T of glass substrate manufacturing E , calculate W by continuously adjusting E when the overflow coefficient, so that the final T E Meet the design requirements; that is, by designing the lead plate width W Y and effective face width W E , so that the glass substrate side plate thickness T E Meet the design requirements; the process parameters are also used to calculate other parameters of the overflow brick, including the guide plate speed V, the average side plate flow rate Q E and the average side plate mass M E To meet the process requirements for manufacturing stable lead plates in glass substrate production lines. The invention effectively solves the problem of fluctuating forming lead plates on site, further optimizes the forming thickness distribution of the glass substrate manufacturing, increases the production margin from the design, and ensures the thickness and consistency of the side plates of the glass substrate.

The invention discloses a delay tripping low-voltage frame switch. The frame switch comprises an under-voltage tripping loop and a time delay unit electrically connected with the under-voltage tripping loop; the time delay unit comprises a voltage detection circuit, a timer circuit, a clock control circuit and a voltage stabilizing circuit; the input end of the voltage detection circuit is electrically connected with the output end of the under-voltage tripping loop; the output end of the voltage detection circuit is electrically connected with the input end of the timer circuit; and the inputend of the clock control circuit and the input end of the voltage stabilizing circuit are electrically connected with the output end of the timer circuit. The delay unit is additionally arranged on an original under-voltage tripping loop, so that the under-voltage tripping loop has a voltage-loss delay disconnection function, power grid fluctuation can be avoided, the delay time is adjustable, and the safety performance is good.