320results about How to "Proof of accuracy" patented technology

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 belongs to the technical field of bloom production and particularly relates to an online detection method for a solidified bottom end position in the bloom continuous casting production process. The online detection method comprises the following steps: first, measuring solidified bloom shell thicknesses by a nail shooting process, establishing a thermal tracking model, calculating to obtain the pre-measurement results of the bloom shell thicknesses at different solid ratios, at different casting temperatures and at different drawing rates in the strand direction, then measuring the rolling reductions of different bloom shell thickness parts when the blooms are rolled by withdrawal and straightening units, establishing a relation curve of bloom shell thickness, pressure and rolling reduction, and establishing a corresponding relational database of steel type, bloom shell thickness, pressure and rolling reduction; in the actual production process, measuring on line when periodical rolling is carried out by each withdrawal and straightening unit, comparing the corresponding relational data of steel type, pressure and rolling reduction with the database, judging the actual bloom shell thickness of the current continuously cast bloom and determining the solidified bottom end position. The method is tightly combined with bloom continuous casting production reality, detection equipment does not need to be increased, and the online detection process of the solidified bottom end is finished by the existing withdrawal and straightening unit.

The invention provides a solar heat accumulating system and a seawater desalting system. The solar heat accumulating system comprises a heat collector, a heat accumulator and a heat using device, wherein the heat collector and the heat accumulator are communicated to form a circulating loop; the heat accumulator and the heat using device are communicated to form a circulating loop; a pipe, where the heat accumulator is located, is connected in parallel with a pipe, where the heat using device is located; the heat collector is used for absorbing energy from the sun and heating water in the heat collector; the heated water flows into the heat accumulator and the heat using device through a water outlet pipe respectively, and water flowing out of the heat accumulator and the heat using device enters the heat collector through a water return pipe for heat exchange. The invention provides the novel solar system and seawater desalting system, and the seawater desalting efficiency is improved through a heat accumulating function.

The invention provides a heat radiator and a combined heat and power generation system including the same. The heat radiator comprises a base tube and external fins, the external fins are sealed, the sealed external fins comprise fins and a sealing sheet for sealing the fins, and the distance between the sealing sheet and the base tube gets closer from the lower portion of the base tube to the upper portion of the base tube. According to the heat radiator and the combined heat and power generation system, the structure of the heat radiator is optimized, heat transfer efficiency of the heat radiator is maximized, energy is saved, and the purposes of environmental protection and energy saving are achieved.

The invention provides a solar heat collector and a seawater desalination system comprising the same. The solar heat collector comprises heat collection tubes, wherein every two adjacent heat collection tubes are connected by the aid of a heat collection plate, so that the multiple heat collection tubes and the adjacent heat collection plates form a tube-and-plate structure. A solar heat collector system comprises two tube-and-plate structures, a certain included angle is formed by the two tube-and-plate structures, the heat collection tubes have rectangular cross sections, and the heat collection plates are connected with corners of the rectangles. The novel solar heat collector and the seawater desalination system can improve the solar heat absorptivity, so that the desalination efficiency of the seawater desalination system can be improved.

The invention provides a method for solving a grinding track of a front tool face of an arc edge of an arc head end mill. The method includes the following steps: firstly, the process characteristicsof the front tool face of the arc edge are defined, and include an instantaneous front tool face of the arc edge in the grinding plane, and a track curve of knifing grinding points (simultaneously constrains the width and front angle of the arc front tool face); secondly, a grinding track and attitude of a grinding wheel in the instantaneous front tool face is calculated; and finally, through spatial coordinate transformation, an actual machining track of the grinding wheel is obtained. According to the method for solving the grinding track of the front tool face of the arc edge of the arc head end mill, a grinding method of the front tool face of the arc edge of the integral end mill is studied in a deepgoing way, and a set of arc front tool face grinding algorithm capable of satisfying smooth transition and simultaneously constraining the front angle and the width; and simulation and machining results show that the method can be effectively used in tooling, the accuracy and feasibility of the grinding method are proved, and a theoretical reference for actual production and machining of cutters is provided.

The invention discloses a power load probability density prediction method based on fuzzy support vector quantile regression. According to the method, maximum day load data and average temperature data before a prediction day are collected; a train set and a test set are established through adoption of history data; lagrangian multipliers and support vector subscripts of a fuzzy support vector quantile regression model are obtained through utilization of the train set; the fuzzy support vector quantile regression prediction model is established according to obtained model parameter values; the test set is substituted into the model to obtain prediction values; and probability density prediction of the maximum day load is realized through utilization of the obtained prediction values under different quantiles and through application of kernel density estimation. According to the method, prediction errors can be effectively reduced, the power load prediction precision is improved, the good prediction effect is obtained, and the relatively reliable basis is provided for a power system scheduling department to adjust power consumption plans and optimize generator set contribution.

The invention provides a control method for online dynamically restraining power grid low frequency oscillation and subsynchronous oscillation. Firstly, power grid voltage and current are acquired via a sensor, and after the voltage and the current are converted into signals readable by a digital processor, online real-time quick FFT is carried out via a digital signal processor (DSP); then, an SVG current control strategy is designed, and the SVG outputs accurate reactive power compensation according to a real-time power grid low frequency oscillation component and a subsynchronous oscillation component. On the basis of the original SVG control strategy, control algorithm for online dynamically restraining power grid subsynchronous oscillation is added, positive damping can be effectively provided with a wind farm, and a wind power generation system is stabilized; and compared with the existing restraining strategy, the SVG can output more accurate and quicker active power and reactive power according to the real-time power grid subsynchronous oscillation component, and the subsynchronous oscillation problem in the power grid is solved.

The invention relates to a bearing degradation state identification and predication method based on variation modal decomposition-transfer entropy, and belongs to the technical field of gear fault analysis. According to the technical scheme, the severity degree of a rotating machinery fault can be effectively reflected through parameters of system nonlinearity and the complexity degree; variationmodal decomposition and a transfer entropy theory based on signal complexity of the nonlinearity kinetic parameters are combined to achieve rolling bearing degradation state identification; and the rolling bearing state evaluation index based on variation modal decomposition-transfer entropy is built, and full-life experimental data of a rolling bearing are predicted through a model. The bearing degradation state identification and predication method provides new and effective means for fault diagnosis, performance degradation state identification and trend prediction of rotating machinery; and the variation modal decomposition-transfer entropy and SVR rolling bearing fault evolutionary trend prediction model is built, the full-life experimental data of the rolling bearing are predicted through the model, and accuracy and effectiveness are improved.

The invention provides a combined heat and power generation system with regulating valves adapting to changes. According to the combined heat and power generation system with the regulating valves adapting to the changes, the first regulating valve is arranged on a hot water supply pipe to regulate hot water entering into a heat exchanger; the second regulating valve is arranged on a water inlet pipeline of a radiator, data connection is conducted between a programmable logic controller and the first regulating valve as well as between the programmable logic controller and the second regulating value, and when the opening degree of the second regulating valve changes, the opening degree of the first regulating valve changes correspondingly to enable the hot water input into the heat exchanger to change correspondingly. According to the combined heat and power generation system with the regulating valves adapting to the changes, the heat exchange efficiency is maximized through the corresponding changes of the regulating valves, the energy is saved, and the purposes of protecting environment and saving energy are achieved.

The invention provides a loop heat pipe-type solar water heater system which comprises a thermal utilization device, wherein the thermal utilization device is hot water output equipment for providing a user with hot water and comprises a heat exchanger; the heat exchanger is connected with tap water; hot water from a solar water heater enters the heat exchanger to exchange heat with the tap water. The solar water heater provided by the invention is energy-saving, and higher in solar heat utilization capability.

The invention provides an intelligent blowdown boiler which comprises an automatic control blowdown system. The automatic control blowdown system is automatically controlled according to the amount of steam generated by the boiler and the amount of water input into the boiler. The water supply amount and the generated steam amount of each boiler are monitored in real time, so that the dynamic relation of the water supply amount and the generated steam amount is obtained, whether the blowdown system of the boiler works normally or not is judged, and waste of a large amount of heat energy waste caused by faults of the blowdown system of the boiler is avoided.

The invention provides a seawater desalination system with a loop heat pipe. The system comprises an evaporation chamber, an acidic gas storage tank, an alkaline solution container and a seawater storage tank. The evaporation chamber is provided with an exhaust port and is connected with the acidic gas storage tank and the alkaline solution container, a first pipeline connected with the seawater storage tank is arranged at the bottom of the evaporation chamber, the seawater storage tank is provided with a second pipeline connected with the evaporation chamber and used for conveying seawater to the evaporation chamber, the first pipeline and the second pipeline are provided with a first valve and a second valve respectively, a pipeline through which the evaporation chamber and the acidic gas storage tank is connected is provided with a third valve, and a pipeline through which the evaporation chamber is connected with the alkaline solution container is provided with a fourth valve. The evaporation chamber is vacuum in a chemical mode, cost is reduced, and seawater desalination performance and efficiency are improved.

The invention discloses a method and device of estimating and verifying a sequence assembly result of three-generation sequencing. The method comprises the steps of comparing a two-generation sequencewith a three-generation assembly result; extending and selecting a low cover degree area, and obtaining the extended sequence; comparing a three-generation sequence with the extended sequence; counting basic group coverage depth; marking the assembly result. The method and device can screen out the area with not too high quality from the three-generation assembly result, and mark the area. In thefollowing species research, a prompt function is provided if the area with not too high quality needs to be used, and a rapid screening method is provided for the following improvement; meanwhile, the accuracy and quality of the three-generation assembly result can be proved, and the accuracy of the assembly result can be improved.

The invention provides a boiler thermodynamic system. The boiler thermodynamic system comprises a central monitoring diagnostic system, a fuel conveying device and a plurality of boilers connected in parallel. Each boiler is in data connection with the central monitoring diagnostic system. The central monitoring diagnostic system is in data connection with each boiler and the fuel conveying device so that the fuel input amount of each boiler can be obtained in time. The central monitoring diagnostic system monitors the ton steam fuel consumption parameter of each boiler in real time according to the obtained mass of steam output by each boiler and the obtained fuel input amount of each boiler. The ton steam fuel consumption of each boiler is the ton steam fuel consumption index obtained by dividing the total amount of steam generated by the boiler during a certain period of time by the fuel input amount of the boiler during the period of time. By means of the boiler thermodynamic system, the thermodynamic system can keep running efficiently all the time, and energy waste can be avoided.

A signal collection and analysis system and method are disclosed. The signal collection and analysis system comprises a main controller, a data converter ADC, a frequency measurement unit and the like. The main controller comprises a main control unit, an auxiliary control unit and a logic gate array, wherein the logic gate array is used for driving an ADC and measuring and calculating frequency of tested signals, and the main control unit is used for realizing man-machine interaction and communication with the auxiliary control unit and a host computer. The low cost and high precision embedded type signal collection and analysis system is characterized in that the logic gate array and a front end circuit can be used for accurately measuring signal frequency, a signal amplitude can be accurately calculated by the main control unit when the signal frequency is known, and the auxiliary control unit is capable of expanding other low speed demands of the main control unit.

The invention discloses a method for functional prediction of single nucleotide genomic variation in a non-coding region, which comprises the following steps: 1) identifying a chromatin open region; 2) identifying transcription factor bin sites; 3) assessing the role of single nucleotide variations: Based on the site-specific frequency matrix of transcription factors, the effect of single nucleotide variations in the transcription factor binding site region on transcription factor binding is calculated, and the single nucleotide variations that significantly change the binding capacity of transcription factors are identified; the role of single nucleotide variations is further evaluated by viewing the biological pathway of the target gene of the transcription factor. The method recognizesa variety of transcription factors and their binding sites at one time through chromatin open region information and gene expression information, and realizes the functional annotation of non-coding region genomic mutation.

The invention relates to a method for determining initial melting temperature of nickel-based superalloy. The segregation influence generated in the solidification process of the superalloy is fully considered; an electronic probe is adopted for accurately measuring the interdendritic component; the component is subjected to computer simulation, so as to simulate the initial melting temperature of an initial melting area; the defects of the conventional determination method for initial melting temperature are avoided; the initial melting temperature of superalloy can be conveniently and accurately measured.