82results about How to "Judgment stability" patented technology

The invention provides a filling mining multi-information dynamic monitoring method, which is applicable to dynamically monitoring the filling mining multi-information of a waste filling mining area. A vertical displacement meter, a horizontal displacement meter, a vertical pressure meter, a transverse pressure meter, a hydrographic comprehensive test instrument and a gas comprehensive test instrument are arranged in a goaf space of a monitoring section; a borehole stress meter and a multipoint displacement meter are arranged in the position corresponding to a sidewall waist line along a direction vertical to the surface, and a borehole arrangement separation layer indicator is arranged on the top part along a direction vertical to the surface; and the vertical displacement, horizontal displacement, vertical pressure, transverse pressure, water level, water flow, water quality, water pressure, gas concentration, CO concentration, temperature, stress of different positions in coal or rock, displacement and separation layer signals are acquired, and output lines through connection boxes are connected to form a bus which is connected with a multi-channel connection box, and the multi-channel connection box is sequentially connected with communication sub-stations under a mine and a main station, so that the monitored signals are dynamically outputted to a ground work station in real time so as to realize the dynamic monitoring of the filling mining multi-information.

The invention discloses a color-changing indicating error-proofing UV electronic adhesive. The color-changing indicating error-proofing UV electronic adhesive comprises following raw materials, by weight, 20 to 80 parts of a UV resin, 0.5 to 3 parts of an initiator, and 0.5 to 5 parts of a color-changing agent; the UV resin is selected from acrylic acid modified polyurethane, epoxy modified acrylate, UV silicone rubber resin, and epoxy resin of cyclic ester group; the initiator is selected from a free radical photoinitiator and a free radical thermal initiator; the color-changing agent is selected from a photochromic polymer with a thiocarbazone coordination compound structure, a photochromic high-molecular compound with an azobenzene structure, a photochromic high-molecular compound with a spirobenzopyran structure, and the like. The invention also discloses a preparation method of the color-changing indicating error-proofing UV electronic adhesive. Color of the color-changing indicating error-proofing UV electronic adhesive before solidification is stable; and difference of the color of the color-changing indicating error-proofing UV electronic adhesive before and after solidification is obvious, so that in production lines, it is possible to quickly identify that whether solidification of the color-changing indicating error-proofing UV electronic adhesive is realized, whether adhesive dispense positions are appropriate, and whether adhesive thixotropic response is induced. In addition, it is possible for direct determination of adhesive stability by associating color with adhesive solidification degree.

The invention discloses a tunnel face stability calculation method taking seepage force into consideration. The method mainly comprises the following steps of (1) according to parameters such as a tunnel burial depth, an excavation size and the like, determining a geometric relation among the tunnel burial depth, the excavation size and a damage range; (2) according to a seepage balance equation and in combination with numerical simulation software, obtaining average seepage force in the damage range; (3) according to an energy conservation principle, obtaining a virtual support force expression of a tunnel face; and (4) reducing surrounding rock parameters in combination with a strength reduction method, so that virtual support force is zero, and a reduction coefficient at the moment is atunnel face stability coefficient. The method disclosed by the invention can be applied to the tunnel face stability analysis of underground building structures such as mining roadways, hydraulic tunnels, metros and the like during consideration of the action of the seepage force under the water level, and a reference is provided for support reinforcement of the tunnel face.

A robot's foot with the shape similar to that of human foot is composed of rubber sole plate under foot plate, foot plate, switch plate, six-component sensor, rubber ring between said foot plate and lower flange, lower flange between foot plate and six-component sensor, upper flange between six-component sensor and switch plate and connected to malleolus joint of robot, and signal processing circuit integrated in said six-component sensor.

The invention relates to a refrigerator energy-saving control method which comprises the steps that at a step 11, an accumulated period Ta of continuity and stabilization of a refrigerator compartment temperature is calculated and / or a continuous accumulated period Td of door closing is calculated; at a step 12, whether Ta is bigger than or equal to a preset stable period TB is judged, a step S13 will be executed if Ta is bigger than or equal to the preset stable period, and otherwise the step 11 will be restarted to continue the calculation at the step Ta and / or whether Td is bigger than or equal to a preset door closing period TE is judged, a step S13 will be executed if Td is bigger than or equal to the preset door closing period, and otherwise the step 11 will be restarted to calculate Td; and at a step 13, an energy-saving mode of a refrigerator is started. The energy-saving mode is started by judging stability of the refrigerator compartment temperature and a door opening state of the refrigerator. A user will be deemed to have not used the refrigerator for a period (such as at night, during working and in a vacation) when a door is closed for a certain period / or fluctuations of the compartment temperature are kept within a certain scope, the refrigerator will enter the energy-saving mode and energy consumption of the refrigerator will be reduced.

The invention discloses a method for preparing nanometer ATO dispersing slurry fast, efficiently and cheaply. The method comprises the following steps: (1) successively adding silane coupling agent and ATO powder in water under stirring according to a weight ratio of to 0.005-0.02:1 to obtain ATO powder suspending liquid with the solid content of 16-55%, adjusting the pH value with alkaline solution to 9-11; (2) placing the ATO powder suspending liquid obtained by the step (1) in a ball mill to perform ball milling for 0.5-7.5 hours which adopts zirconium beads as ball-milling beads, removing the ball-milling beads to obtain slurry, fast adjusting the pH value with alkaline solution to 6-8; and (3) centrifuging the slurry obtained by the step (2) in a centrifugal machine under the rotate speed of 1000-4000rpm to obtain the nanometer ATO dispersing slurry. The preparation method of the invention is characterized by fast speed, electricity-saving and high efficiency; the average diameter of the particles of the prepared slurry is 25-50nm, the solid content is 15-50%, and the dispersing effect is very good.

The invention provides a method for predicting the stability of vehicles, and belongs to the field of automotive technologies, and the method can be used for solving the problem that in the prior art, methods for predicting the stability of vehicles are not high in accuracy and low in reliability. The method comprises the following steps: S10, detecting an acting force Fi exerted on each wheel of a target vehicle by the ground; S20, analyzing and calculating a force-center coordinate vector as shown in the specification of the target vehicle; and S30, substituting the force-center coordinate vector as shown in the specification into a vehicle force-center / stability transfer function which is as shown in the specification and is pre-stored in a vehicle-mounted controller of the target vehicle so as to calculate a stability signal Scar of the target vehicle, and according to the value of the stability signal Scar, judging the current stability state of the target vehicle; a test vehicle and the target vehicle are same in type or similar in technical parameter, the test vehicle is defined as a vehicle for calibrating test data under experimental conditions, and the target vehicle is defined as a vehicle normally running on the road. The judging process in the method is simple and convenient, and the method is accurate in judgment and high in reliability.

The invention provides a dynamic stability judgment method of a single-slider variable-mass-center control aircraft. Dynamic stability of a system under different slider offset distances can be judged. The method includes the steps that first, projectile body parameters and flight condition parameters of a reentry vehicle to be analyzed are obtained; second, the aerodynamic coefficient of the aircraft under the flight condition is obtained through aerodynamic analysis software or a wind tunnel test; third, the maximum stable offset distance zm is calculated according to the obtained parameters and the aerodynamic coefficient; fourth, whether the slider offset distance is smaller than the maximum stable offset distance obtained in the third step obtained in the third step or not is judged, if the slider offset distance meets the formula that |z|< zm, the system is stable in terms of attitude dynamics, and nutation movement of the aircraft can converge to a balance point; if |z|>= zm, the system is unstable in terms of attitude dynamics, and at the moment, the nutation angle of the aircraft tends to diverge along with time.

The invention discloses characteristic value analysis model and step for the subsynchronous resonance analysis of a multi-machine power system, relating to the field of characteristic value analysis models of the subsynchronous resonance analysis of the power system. The deducing and calculating process of a method comprises the following step of: respectively writing a rotor motion equation of amultimass block model of a shaft system of a steam turbine generator, an electromagnetic transient state equation of a magnetic chain and the voltage of a generator, an electromagnetic transient state equation of a power transmission line, an electromagnetic transient state equation of a series-connected compensation capacitor and a control system equation of an excitation controller and the like. The invention obtains a differential equation set related to a state quantity by linearizing the equations on a stable-state operating point and can solve the characteristic value and the characteristic vector of a state equation coefficient matrix on the basis, obtain much information related to resonance damping characteristics by judging the stability of the subsynchronous resonance of the multi-machine power system and can be used for designing a controller to inhibit the subsynchronous resonance of the multi-machine power system by combining with a control theory.

The invention discloses a method for evaluating the stability of a multi-inverter grid-connected system in two dimensions, which comprises the steps of (1) loading parameters of the grid-connected system for system modeling; (2) establishing a full admittance form equivalent circuit of the grid-connected system; (3) deriving a grid-connected current expression of inverters in the grid-connected system and a transfer function of global admittance in s domain; (4) dividing the global admittance into a real part dimension and an imaginary part dimension, and analyzing the stability of the grid-connected system in the two dimensions. According to the stability evaluating method provided by the invention, whether the real part is greater than 0 or not at the part where the virtual part of the global admittance is 0 is analyzed, thereby not only being capable of clearly judging the stability of the grid-connected system, but also being capable of obtaining accurate resonance point information, acquiring essential factors affecting the stability of the parallel operation system, indicating the direction of resonance suppression, and having excellent feasibility and practical values.

The invention relates to an error debugging method for an electronic electric energy meter, and belongs to the technical field of electric energy meter debugging. The error debugging method comprises the steps of firstly judging the accuracy and the stability of a standard meter in output; continuously reading power effective values of the standard meter and power effective values of an electric energy meter to be tested if the standard meter conforms to requirements; respectively calculating an average power effective value of the standard meter and an average power effective value of the electric energy meter to be tested according to the read power effective values of the standard meter and the read power effective values of the electric energy meter to be tested; and finally calculating an error of the electric energy meter to be tested according to the acquired average power effective value of the standard meter and the acquired average power effective value of the electric energy meter to be tested, and carrying out debugging on the electric energy meter to be tested according to the error. According to the invention, the error of the electric energy meter is calculated through a mode of the power effective values, the error calculation time of the electric energy meter is shortened, and the error debugging efficiency is improved. Meanwhile, the invention can also judge the accuracy and the stability of a debugging and detecting platform in output, thereby avoiding a quality problem caused by problems of the debugging and detecting platform.

The invention discloses a rapid and accurate monitoring system for the deformation of surrounding rock of an underground roadway and a monitoring method of the system. The system comprises a rubber belt, code reference points, non-code reference points, a fixed scale, cameras and a computer; each non-code reference point is composed of a non-code center point, and each code reference point consists of a code center point and annular codes. The monitoring method of the system comprises the steps that S1, the rubber belt is fixed on the section of the roadway, wherein the shape of the rubber belt is identical to that of the section of the roadway; S2, the code reference points and the non-code reference points are inserted in the rubber belt at intervals, and the fixed scale is hung betweentwo code points; S3, the cameras are connected with the computer, and camera lens are aligned with the rubber belt; S4, an automatic photographing mode is adopted for recording the movement process ofthe code reference points and the non-code reference points; S5, collection is completed, and photo information is transmitted to the computer; S6, system measurement software calculates the three-dimensional coordinate changes of the code reference points and the non-code reference points; S7, the deformation of the surrounding rock of the entire roadway is analyzed.

The invention discloses a device and a method for testing electrical conductivity of slurry. The device comprises a sealed container with an upper cover, a magnetic stirrer placed outside the bottom of the sealed container, a stirring rotor placed in the sealed container, a micro vacuuming pump communicating with the sealed container, two conductive current collectors placed in the bottom of the sealed container, a direct current resistance testing instrument electrically connected with the two conductive current collectors, an infrared temperature measuring and controlling instrument for detecting the internal temperature of the sealed container, and a material feeding mechanism and a discharge mechanism which are in communication with the sealed container. By adopting the device providedby the invention, a resistance test can be conducted directly on the slurry, so as to judge the dispersibility and the conductivity; at the same time, the method can also be directly configured to the conductive slurry with different solid content, and stirring in large mixing equipment is not needed, so that materials are saved; the influence of the slurry with same solid content on the electrical conductivity at different time and at different temperatures can be clearly seen in data, the stability of the slurry can be judged, the accuracy of the conductivity evaluation of the slurry can beenhanced, and the work efficiency can be improved.

The invention relates to a detection method and apparatus of communication performance of a vehicle-mounted terminal, belonging to the field of vehicle-mounted terminal performance detection. In the existing communication procedure, JT / T808-2014 is not used for detecting the performance of the vehicle-mounted terminal. The invention provides the detection method and apparatus of communication performance of the vehicle-mounted terminal, overcoming the defect in the existing communication procedure. The method comprises the steps of receiving a registration instruction sent out by a vehicle-mounted terminal and sending out a reply instruction; receiving an authentication instruction sent out by the vehicle-mounted terminal and sending out a reply instruction; detecting authentication success times; reading configuration parameters of the vehicle-mounted terminal; and detecting a time difference between a current time and a preset time, if the time difference exceeds 24 hours, sending out a sell credit instruction for enabling the vehicle-mounted terminal to register and authenticate again a certain time later; storing all generated instructions in a log; and analyzing the log so as to determine whether recording time of the instructions in the log is continuous, so as to determine the correctness of the communication data of the vehicle-mounted terminal. The method and apparatus are applicable to detection of communication performance of the vehicle-mounted terminal.

The invention relates to an automatic single particle irradiation test control system and method. The system comprises an experimental instrument program control module, a fluence rate monitoring module, an error number counting module and a timing detection module. According to the invention, the automatic opening and closing of the chip irradiation test are realized by presetting an irradiationcondition threshold value, the automation degree of the integrated circuit single particle irradiation test is effectively improved, and the waste of a single particle irradiation tester and the workload of an experimenter are reduced; and meanwhile, the generated data file contains all test data (particle fluence rate, total particle fluence, test current, single particle error number and test waveform), so that the single particle test accuracy is improved, and is beneficial to the subsequent personnel to analyze the test result.

The utility model provides a method of testing connectivity of cluster call, which is characterized in that: firstly, acquisition and statistics to the test data of spicing time-period of the cluster call are performed, so as to get the spicing time sample of each test which comprises the testing times and the specific time-scale of each test in the spicing time sample; secondly, the time range which is to be analyzed into multi time slices is divided according to the predetermined time interval, and the number of each specific time-scale distributed in each time slice in each spicing time sample is counted, and then the percentage M of the spicing time in different test set falling into each time slice is computed and gained; thirdly, the percentage Ms in different test set falling into each time slice in the predetermined time range is added, and the adding result is compared so as to get the performance evaluation of testing connectivity of the cluster call. The utility model has the advantages of improving the accuracy of testing connectivity of the cluster call.

The invention relates to a fault positioning system and method based on video image diagnosis data, and the system comprises a front-end equipment camera system which comprises a full-path camera and is configured to shoot video image information; a comprehensive video monitoring system which is configured to check the real-time video and the recorded video shot by the front-end equipment camera system; and a video operation and maintenance system which is configured to perform quality diagnosis on the video images acquired by the comprehensive video monitoring system to determine video monitoring fault types and position fault causes. The method can be used for centralized management and operation and maintenance of video service related equipment and systems, provides intelligent service of fault positioning analysis for users, assists operation and maintenance management personnel in judging the safety and stability of video operation, and provides powerful support for production operation and maintenance decision making.

The invention discloses a high-temperature sedimentation stability test device for cement paste. The high-temperature sedimentation stability test device mainly comprises a base support 25, a maintenance kettle 7, a paste cylinder 6, an upper pressure sensor 21, a lower pressure sensor 20, a temperature sensor 11, a control panel 8, a computer 9, a gas source 1 and a water source 2, wherein the paste cylinder is placed in the maintenance kettle; heaters 15 are arranged between the paste cylinder and the maintenance kettle; an outer magnet 23 driven by a belt pulley 22 is arranged in the kettle body; the temperature sensor is inserted into the maintenance kettle and connected with the control panel and the computer; an inner magnetic rod 12 of a driver at the upper part of the paste cylinder is connected with a mandrel 13; the outer magnet of the maintenance kettle drives the inner magnetic rod in the paste cylinder to rotate to drive a paddle 16 to stir cement paste in the paste cylinder; the paste cylinder is provided with the upper pressure sensor and the lower pressure sensor which are both connected with the control panel and the computer; a driver plug 10 is connected with the gas source through a pressure regulating valve 3; the maintenance kettle is connected with a water source. The high-temperature sedimentation stability test device is reliable in principle, reasonable in structure and simple and quick in test, and can measure the sedimentation stability of different cement paste systems in different high-temperature environments.

The invention discloses a grid-connected system short circuit ratio measurement method and device based on fundamental wave impedance identification. The grid-connected system short-circuit ratio measuring device based on fundamental wave impedance identification comprises a master grid-connected inverter, a short-circuit ratio calculating unit, a slave grid-connected inverter and a weak power grid. Specific operation process of the experimental device for measuring the short circuit ratio of the grid-connected system is as follows: the disturbance injection unit injects disturbance signals into the grid-connected inverter, current response signals and voltage response signals of a common coupling point PCC are collected through the grid-connected current sensor Hig and the grid-connectedvoltage sensor Hug respectively, fundamental wave impedance is obtained through the fundamental wave impedance identification unit, and then the short-circuit ratio of the system is obtained through calculation. The experimental device can accurately and reliably calculate the short circuit ratio of the grid-connected system, so that the experimental device is applied to stability judgment and self-adaptive control of the grid-connected system, and the stability of the grid-connected system is improved.

The invention relates to a generator set power output stability detection system based on power detection. The system comprises a prime mover detection module, a generator detection module, a virtualload module, a central control module and a display module. The virtual load module is used for testing the generator set; the load module is controlled by the central control module to select small interference variation of different magnitudes in sequence to cause small interference of different degrees to the running generator set in sequence. And the static stability of the generator set is quickly and visually judged according to the time length required for recovering the stability of the generator set after the generator set is interfered, so that the judgment efficiency of the generator set power output stability detection system based on power detection is improved. Meanwhile, the system can effectively improve the universality of the detection result of the system by sequentiallyrecording the duration required for recovering the stability of the generator set under the condition of different magnitudes of load disturbance and counting the total duration.

The invention relates to a method for judging the reinforcement stability of a long pipe shed in a tunnel intrusion contact zone, and belongs to the field of tunnel foundation construction. The distance z from the ground of the intrusion contact zone to a tunnel vault, undrained shear strength cu of a soil body in the intrusion contact zone, thickness dz of the long pipe shed after grouting, diameter d1 of a steel pipe of the long pipe shed, wall thickness delta, shear strength cp of the long pipe shed, shear strength cc of a grouting body, average shear strength cc and p of the long pipe shedand the grouting body after weighted averaging according to area, shear capacity Kj of the long pipe shed, perimeter L of a cross section of the grouting body of the long pipe shed, length Ld1 of a shorter side of the long pipe shed embedded in a surrounding rock on the inner side of the intrusion contact zone, length Ld2 of a shorter side of the long pipe shed embedded in the surrounding rock onthe outer side of the intrusion contact zone, shear strength t1 between the grouting body of the long pipe shed and the surrounding rock on the inner side of the intrusion contact zone, shear strength t2 between the grouting body of the long pipe shed and the surrounding rock on the outer side of the intrusion contact zone, and reinforcement carrying capacity K of the long pipe shed are determined in sequence, and the reinforcement stability of the long pipe shed in the tunnel intrusion contact zone is judged to avoid slump of the intrusion contact zone.

The invention relates to a method for extracting and judging operation data stability of ship electromechanical equipment. The method comprises the following steps: acquiring ship electromechanical equipment data, preliminarily judging data stability, calculating the minimal length of a stable inspection data segment, judging data stability point by point, correcting the stability inspection result as well as storing and outputting results. The defects that true stable data is difficult to judge simply by the statistic method and large-range judgment error occurs in the prior art are overcome.Through the judgment method, the stable operation data of the electromechanical equipment is extracted, accuracy and reliability of modeling, evaluation and even optimized decision can be improved, and important significance in analysis and research of ship data is achieved.

The invention relates to a rapid dynamic load model characteristic coefficient calculation method and belongs to the electric power system stabilization and control technology field. The method comprises steps that a slip ratio is calculated; according to relationships between the slip ratio and the frequency and the voltage, relationship expressions of active power and reactive power absorbed by an induction motor are solved; according to the acquired active power and the acquired reactive power, the partial derivatives of the stator side frequency are solved respectively, the partial derivatives are multiplied by a ratio of the initial frequency to an initial power to acquire a frequency characteristic coefficient expression; according to the acquired active power and the acquired reactive power, the partial derivatives of a power source voltage are solved respectively, and the partial derivatives are multiplied by a ratio of an initial voltage to the initial power to acquire a voltage characteristic coefficient expression. The method is advantaged in that the complex calculation process is simplified, the calculation time and workload are saved, and the relatively simple relationships among the active power, the reactive power, the slip ratio, the frequency and the voltage are acquired.

The invention relates to an electromagnetic flow velocity flow rate measuring device based on real time attitudes and a measuring method thereof, and belongs to the hydrology data measuring technologyfield; the measuring device comprises a pressure sensor, an electromagnetic flow velocity meter, an attitude sensor, a CPU circuit, a control switch, a LoRa circuit, an antenna and a host computer; the electromagnetic flow velocity meter gathers real time single point current speed; the pressure sensor gathers real time air pressure, water pressure and water temperature data; the attitude sensorgathers real attitude data of an underwater lead fish; the CPU circuit stores real time attitude data, pressure data and flow velocity data, and sends the data to the host computer through the LoRa circuit and the antenna; the host computer parses and fuses to obtain three dimensional attitude angle data and water depth data, and the flow velocity data is combined, thus calculating to obtain the current flow rate data. The method and device employ the electromagnetic flow velocity meter to measure the flow velocity, select the flow velocity data under stable states according to real time altitudes, thus accurately measuring flow velocity and calculating current flow rate; the measuring method and device are suitable for various complex water area environments.

The invention discloses a high-risk assessment system in the operation process of a power system. The system comprises a data collection station, a data processing platform, and a risk assessment system, the data collection station is in wireless connection with the data processing platform, and the data processing platform is in wireless connection with the risk assessment system. According to the invention, with the data acquisition station, the data processing platform and the risk assessment system, a data acquisition module acquires danger generation data of each monitoring point in a power system; the acquired dangerous data are transmitted to the data processing platform; the data processing platform performs data analysis on the acquired dangerous data; the risk generation probability is estimated, the estimation result is sent to the risk assessment system, the risk assessment system performs risk assessment analysis by combining the acquired risk data and the estimation result, the stability of the power system is judged, and various risk generation conditions in the power system are predicted.

The invention provides an elevator safety and synchronous self-rescue device. The elevator safety and synchronous self-rescue device is characterized by comprising an elevator car synchronizer, a self-rescue device and a synchronous detecting device, wherein the elevator car synchronizer is connected with an elevator car through a rack on a lifting guide rail; the self-rescue device is connected with the elevator car synchronizer through a clutch; and one end of the synchronous detecting device is connected with the elevator car, and the other end is connected with a fixed part of the elevator car synchronizer. The synchronous operation of the elevator safety and synchronous self-rescue device and the elevator car is realized; the elevator car is accurately positioned; persons trapped in an elevator can realize self rescue through manually driving the elevator to a safety position or an exit under the condition of not damaging the elevator car on occasions of power failure, rupture of an elevator lifting rope or other elevator faults; and meanwhile, the operation stability of the lifting rope of the elevator car can be judged to a certain extent. The elevator safety and synchronous self-rescue device is high in efficiency and small in time consumption, saves the manpower, the material resources and the financial resources, timely rescues persons trapped in the elevator, and guarantees the safety of the trapped persons.

The invention discloses a device and a method for detecting N-type silicon on the edge of a polysilicon wafer. The device comprises an operation platform, a universal meter, a universal meter fixing bracket, a red copper sheet and a red copper sheet support frame, wherein the universal meter fixing bracket and the red copper sheet support frame are arranged on the operation platform; the universal meter is fixed on the universal meter fixing bracket; and the red copper sheet is flatly put on the red copper sheet support frame. According to a detection technology disclosed by the invention, components are simple; and maintenance and repair are not needed basically. A resistance value from the front surface of the wafer to any point on the edge can be detected through the detection method, so that the problems of the stability of an etching process, the smoothness of idler wheels and a bracket of a machine and operations of the staff can be judged by easily detecting the removal condition of the N-type silicon on the edge of the polysilicon wafer.

The invention discloses a method for controlling assembly temperature in a photovoltaic assembly temperature coefficient test. The method includes the following steps that: step one, a photovoltaic assembly is arranged in an environmental test box; step two, temperature in the environmental test box is heated to test temperature through a heating device; step three, the photovoltaic assembly is stabilized for 50 min to 60 min under a set ambient temperature, so as to achieve thermal equilibrium; and step four, a photovoltaic assembly electrical performance testing system is utilized to perform power testing on the photovoltaic assembly under a test temperature condition. With the method adopted, the difference of detection temperature and the temperature of a power generation device in the assembly can be decreased as much as possible, and the working characteristics of the assembly at various temperature points can be tested more accurately, and rendered temperature coefficients more accord with the performance of the assembly in an actual work process, and the stability of a product can be judged more accurately.

The invention discloses a method for judging the small-interference stability of a converter grid-connected system under polar coordinates. The method comprises the steps: acquiring an admittance model of a converter and a power grid under coordinates by linearly processing a dynamic equation of the converter grid-connected system, and then establishing an admittance model of the converter and anadmittance model of the power grid; performing coordinate transformation on the admittance model of the converter and the admittance model of the power grid under the dq coordinates to obtain a converter admittance model and a power grid admittance model under the polar coordinates; obtaining a single-input single-output closed-loop system model and a closed-loop characteristic equation, and performing judging by using a Nyquist curve according to the closed-loop characteristic equation or calculating the stability margin of the system according to the closed-loop characteristic equation to obtain a result whether the current control parameter of the converter can enable the converter to operate stably or not. According to the method, the stability margin of the converter grid-connected system can be effectively calculated, the influence of the control parameters of the converter on the stability of the grid-connected system is judged, and the instability problem caused by improper setting of the control parameters of the converter is avoided.

The invention relates to a monitoring device for formation fluid pressure of a core sample, comprising: a housing with a hollow area inside; an end cover fixedly installed at the upper port of the housing; located in the hollow area and close to the A plugging part is provided at the bottom of the housing; a sleeve assembly is sleeved on the outer peripheral wall of the end cover and the plugging part to be configured as a holding area for accommodating rock core samples, wherein the sleeve The outer wall of the component is provided with pressure support parts at intervals in the circumferential direction and radial direction; correspondingly installed in the pressure support part, the pressure monitoring component used to monitor the pressure transmission of the core sample in different directions. The monitoring device has the advantages of effectively monitoring the pressure transmission in different directions of the core sample, and also has the advantages of simple and reliable structure, accurate monitoring results and accurate judgment of wellbore stability.