373 results about "Square wave" patented technology

The invention discloses a data stream dynamic mode perception privacy protection method based on local differential privacy, which comprises the following steps: a client selectively captures salient points, retains a data trend while reducing the number of samples, and enhances the disturbance precision of each point to improve the overall data utility; the client side represents the importance of the salient points by calculating PID; the client obtains a sampling point by calculating a sampling rate so as to improve data utility; the client uses a dynamic privacy budget allocation method which adapts to the importance of current and future sampling points so as to optimize budget allocation on a time sequence; the client uses a square wave mechanism to disturb the salient points, and w event level differential privacy is used. According to the method, the user is allowed to select the salient points according to the statistical characteristics of own data, and then the privacy budget is allocated according to the importance of the salient points so as to disturb the salient points.

The invention discloses a tower grounding grid multi-frequency composite wave electric field imaging and soil environment medium diagnosis method, which comprises the following steps of: generating a composite excitation signal through superposition of a low-frequency sine wave and a high-frequency CHIRP square wave, and collecting multi-dimensional data such as voltage / current response, soil temperature and humidity, electric field intensity and the like in combination with a distributed sensor array; separating signal features by using wavelet transform and extracting impedance information of a target frequency point; a multi-grid homotopy algorithm is adopted to realize grounding grid three-dimensional resistivity distribution reconstruction, corrosion spots and abnormal areas are marked, and high-precision positioning of underground conductors is completed through UWB radar or a capacitance detector; meanwhile, based on the information entropy maximization optimization frequency band combination, the grounding grid state is comprehensively evaluated in combination with a multi-parameter fusion model. The method has the non-contact patrol capability, the unmanned aerial vehicle carries equipment to scan the grounding grid, the detection efficiency and convenience are remarkably improved, and an efficient and accurate solution is provided for guaranteeing safe operation of the power grid.

The embodiment of the invention provides a coating layer wall thickness pulse eddy current detection method and system based on multiple eddy current rings, and the method comprises the steps: applying a square wave excitation signal to an excitation coil, and carrying out the induction in a structural member with a coating layer to generate eddy current; collecting a voltage signal generated by induction of an attenuation magnetic field generated by the eddy current by using a receiving coil, wherein the attenuation process of the voltage signal comprises three stages; identifying a power function interval of the second stage to determine the starting time of the third stage; taking the starting time of the third stage as a reference, and selecting a preset thickness quantitative time interval in the third stage; calculating a first-order derivative of the voltage signal to time under a single logarithmic coordinate system in the thickness quantitative time interval to obtain a slope; according to the quantitative relation between the slope and the wall thickness of the structural part with the coating layer, the wall thickness value of the structural part with the coating layer is obtained through calculation.

The invention relates to a magnetotelluric noise suppression method based on ResAtt-CAE, and the method comprises the steps: generating a noise-free signal, adding a noise type into the noise-free signal to construct a noisy signal, and enabling the noisy signal to be matched with the corresponding noise-free signal to form a training set and a test set; designing a ResAtt-CAE model architecture, and realizing cross-level feature fusion by adopting a symmetric structure and jump connection; the ResAtt-CAE model architecture is trained and optimized through the training set and the test set, and the magnetotelluric noise is suppressed through the optimized ResAtt-CAE model architecture. The method is high in noise suppression capability: ResAtt-CAE captures cross-time scale signal features through multi-scale residual learning, enhances effective signal weights in combination with a time domain attention mechanism, and has a remarkable suppression effect on common magnetotelluric noise (square waves, harmonic waves, pulses, triangular waves and the like).

The invention discloses a permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control method and a permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control system, and the permanent magnet synchronous motor full-speed-domain position-sensorless hybrid control method is constructed by taking a permanent magnet synchronous motor nonlinear dynamic system model as a starting point. A hybrid control method combining high-frequency pulsating square wave signal injection under a linear dynamic system model, a rotor polarity judgment and rotor initial position estimation algorithm and an unscented Kalman filtering extension algorithm in an additive noise form under a nonlinear discrete dynamic system model is adopted; and obtaining the optimal estimation observation value of the system state variable in the static, low-speed, medium-speed and high-speed full-speed domain range under the condition that the permanent magnet synchronous motor is not provided with a mechanical position sensor. The optimal estimation observation value is used for compensating and feeding back a permanent magnet synchronous motor drive control system adjusting strategy, disturbance of load torque is improved, the noise amount and disturbance amount introduced by three-phase current measurement are eliminated, and efficient and accurate control operation of the permanent magnet synchronous motor is achieved.

The invention discloses a super-flat wire common-winding motor and a design method, and belongs to the technical field of motor design and manufacturing. The invention discloses an equal-pole common-winding axial magnetic flux motor and a design method, the equal-pole common-winding axial magnetic flux motor comprises a motor winding, a stator, a rotor, a casing and the like, and is characterized in that the number of magnetic poles of the stator and the number of magnetic poles of the rotor are equal, all the magnetic poles of the stator or the rotor on the same disc are excited through the same annular coil winding, and the winding can be a conventional round wire, a flat wire or a super-flat wire; alternatively, two or more concentric circle winding units, such as an outer ring winding unit and an inner ring winding unit, can be arranged on the same disc, radially adjacent iron cores can be shared or can also be independently arranged, meanwhile, the radial size of the shared iron core can be wider in consideration of the magnetic saturation problem, or the radial size of the shared iron core can be smaller in consideration of the magnetic saturation problem. The radial sizes of the iron core and the winding in the small-diameter area can be larger; the working principle can be a reluctance type, a switch reluctance type, a permanent magnet synchronous type, a direct-current motor type or an alternating-current motor type; the direct current motor can be a commutator or a plane commutator; or a brushless control scheme; the alternating current motor can be square wave, sine wave or other waveform; the phase difference of the three-phase alternating current can be 120 degrees; or two-phase or four-phase alternating current or other phase difference current with the phase difference of 90 degrees.

The embodiment of the invention provides a temperature detection circuit and method and electronic equipment, and the circuit comprises a temperature detection module which comprises a detection capacitor; the detection capacitor is used for generating a corresponding capacitance value according to the internal temperature of the electronic equipment; the conversion module is connected with the detection capacitor, and the conversion module is used for controlling the detection capacitor to charge and discharge repeatedly under the corresponding capacitance value and outputting a square wave signal according to the charge and discharge state; and the control module is connected with the conversion module and is used for acquiring the corresponding internal temperature according to the square wave signal. According to the electronic equipment, the detection capacitor is used for replacing a thermistor or a temperature sensor in an existing scheme to detect the temperature of the electronic equipment, and the detection capacitor has a direct current blocking effect, so that quiescent current cannot be generated, and the effect of reducing static power consumption can be achieved.

The present invention provides a flywheel energy storage flux adjustable induction motor and its magnetic adjustment method, wherein the motor comprises two permanent magnets with different coercive forces and a DC magnetic adjustment winding. A square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field, so that the residual magnetism of the low-coercive force permanent magnet changes in magnitude or direction, thereby realizing rapid adjustment of the motor air gap flux. When the motor is working, the DC magnetic adjustment winding is disconnected, and the residual magnetic flux generated by the high-coercive force permanent magnet and the low-coercive force permanent magnet enters the air gap in parallel to provide excitation flux for the motor; when the motor is on standby, a negative square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field that can reversely saturate magnetize the low-coercive force permanent magnet, so that the low-coercive force permanent magnet is reversely magnetized, and the residual magnetic flux of the high-coercive force and low-coercive force permanent magnets is equal in magnitude and opposite in direction, so that the air gap flux is reduced to 0, thereby eliminating standby iron loss. In addition, the DC magnetic adjustment winding can also be used as a backup excitation source to prevent the risk of permanent magnet demagnetization.

The invention provides a random rotation speed-oriented gear meshing stiffness calculation method, which belongs to the technical field of gear performance evaluation, and comprises the following steps: describing the actual operation state of a gear system by using a random rotation speed; determining the total potential energy of the gear according to the acting force of the meshing points; solving the total potential energy of the gear to obtain a potential energy calculation function about a meshing rotation angle; determining a meshing stiffness calculation function about the meshing rotation angle by using the potential energy calculation function; solving an average value of a single-tooth meshing area and a double-tooth meshing area of the meshing stiffness calculation function; and the meshing rigidity is simplified into a square wave function through the average value, and the meshing rigidity is changed into a time function from a corner function through the generated random rotating speed. According to the method, the running state of the gear system is described by using the random rotating speed, the influence caused by random fluctuation of the rotating speed is considered, the meshing rigidity of a wind power gear box and the like in the actual working environment can be reflected more truly, and the accuracy and applicability of meshing rigidity calculation are remarkably improved.

The invention discloses a thermal management system based on double-layer phase change and air cooling cooperative heat dissipation. The system comprises a battery module, a first-stage phase change layer, a second-stage phase change layer, a binding post, a supporting plate, a sleeve and an air cooling channel. The double-layer phase-change cooling device is filled with two composite phase-change materials with high heat conductivity coefficients, and the composite phase-change materials are distributed in the radial direction, so that heat generated by the battery can be quickly absorbed, and the temperature in the battery module is kept uniform. And when the power battery module operates for a preset time length, the air cooling device is automatically started, and part of heat absorbed by the phase change device is dissipated to the environment. The air cooling system adopts a square wave type air supply strategy, that is, intermittent cooling airflow is provided by periodically starting and stopping a fan. By combining the double-layer phase change cooling and air cooling technology, the problems of non-uniform internal temperature distribution and local overheating of the battery module are effectively improved, the applicable working condition range of the battery module is expanded, and the stability and reliability of the system are improved.

The invention provides a frequency selective surface inverse design method, device and equipment. The method comprises the steps of obtaining a target square wave; the target square wave is used for representing the expected transmission performance of the frequency selective surface; inputting the target square wave into a pre-trained multi-layer perceptron model to obtain a target design parameter corresponding to the frequency selection surface; the pre-trained multilayer perceptron model is obtained by training based on a preset sample data set; the preset sample data set is an equivalent circuit model established based on a transmission line theory, and is calculated by adopting an equivalent inductive reactance and capacitive reactance empirical formula. According to the method, the equivalent circuit model based on the transmission line theory is used for replacing full-wave simulation, the complex electromagnetic field solving process is avoided, the sample data preparation time is remarkably shortened, due to the fact that the pre-trained multi-layer perceptron model is introduced, the target square waves are directly mapped to the corresponding design parameters, rapid and efficient reverse design is achieved, and the method is suitable for large-scale popularization and application. And the efficiency and the precision of the frequency selective surface design are obviously improved.

The invention belongs to the technical field of nondestructive testing, and particularly relates to a delayed sampling infrared nondestructive testing method and system based on a uniform light field. The invention provides a delayed sampling infrared nondestructive testing method and system based on a uniform light field in order to solve the problems of an active infrared nondestructive testing method in the aspects of light beam uniformity, defect contrast, reflected light interference and the like. The delay sampling infrared nondestructive testing method based on the uniform light field comprises the following steps that 1, synchronous square wave signals and continuous pulse wave signals are generated, and the continuous pulse wave signals are delayed from the square wave signals; 2, the square wave signal controls a laser 3 to alternately change between a light emitting state and a light extinguishing state through periodic switching of high and low levels; and step 3, energy emitted by the laser 3 is in near Gaussian distribution, and non-uniform laser is transmitted to the light beam homogenizer 5 through the optical fiber 4.

The invention discloses a novel permanent magnet synchronous motor sensorless compound control strategy, and relates to the field of motor control. The method comprises the following steps: replacing a traditional proportional-integral controller with a nonsingular terminal sliding mode controller in a speed outer ring design, using an integral sliding mode surface, omitting an integral link of a q-axis given current, and replacing a sign function with a sigmoid function to improve the dynamic performance and robustness of a system; a high-frequency square wave injection method is adopted to carry out low-speed-domain position-sensorless control, in a middle-high-speed domain, aiming at the system buffeting problem caused by a traditional sliding mode observer, super-spiral sliding mode observation is adopted to carry out rotation angle observation, and meanwhile, an orthogonal phase-locked loop is adopted to eliminate the influence of large numerical value difference possibly occurring due to angle errors. The invention provides a novel permanent magnet synchronous motor sensorless compound control strategy, namely an angle-speed time-sharing weighted hysteresis switching strategy, aiming at the problem that the stability of a transition area is affected due to the fact that the traditional weighted switching in compound control possibly causes large deviation of the relation between the rotating speed and the rotor position. The non-singular sliding mode speed controller, the high-frequency square wave injection method, the improved super-spiral sliding mode observer method and the angle-speed time-sharing weighted hysteresis switching strategy are applied to the full-speed-domain sensorless control system, and the high-performance surface-mounted permanent magnet synchronous motor sensorless control system is achieved.

The invention provides a method for identifying lithology, and belongs to the technical field of geophysical exploration. The method comprises the following steps: acquiring magnetic field amplitude data obtained by inversion of a natural electromagnetic field; preprocessing the magnetic field amplitude data; carrying out square wave layering processing on the preprocessed magnetic field amplitude data and taking values layer by layer; magnetic field lithology sensitive parameters are extracted based on the magnetic field amplitude data after square wave processing; establishing a lithology identification plate and a lithology identification standard based on the magnetic field lithology sensitive parameters and the resistivity lithology sensitive parameters; the resistivity lithology sensitive parameters are obtained from logging data; and identifying lithology distribution of different depths based on the lithology identification plate and a standard. Therefore, the acquisition cost of the electromagnetic survey method is reduced, and the lithology is identified by using the electromagnetic survey method.

The invention discloses a direct-current power transmission system EM lightning arrester zinc oxide resistor disc selecting and balancing method, and belongs to the technical field of lightning arrester disc selecting and matching. The disc selecting method comprises the steps that S1, direct-current parameter testing is carried out, and damped and aged resistor discs are removed based on the direct-current parameter testing result; s2, applying lightning and operation impact to the resistor discs, measuring residual voltage, calculating a voltage ratio based on the residual voltage, and rejecting the resistor discs of which the voltage ratio deviation is not within a set voltage ratio threshold range; s3, carrying out square wave energy testing on the resistor discs, and removing the damaged resistor discs in the testing process; s4, performing long-wave residual voltage test on the resistor discs one by one by using the test square wave, recording a long-wave residual voltage value obtained by the test, and removing the resistor discs which are subjected to breakdown, flashover and aluminum surface burning in the test; calculating long-wave residual voltage deviation of the resistor discs under square wave excitation, and removing the resistor discs with the long-wave residual voltage deviation exceeding a set long-wave residual voltage deviation threshold value; and the sheet selection scheme of the EM lightning arrester is perfected, and the accident rate is reduced.

The invention discloses a closed-loop control method and device for a single transmitting side analog circuit of a wireless power transmission system, and the method comprises the steps: constructing a power transmission structure of the wireless power transmission system based on an SS-type two-coil wireless power transmission topology and an E-type power amplifier, and carrying out the power transmission; obtaining a voltage signal and a current signal by using a signal detection circuit; inputting the signal into a receiving side information back calculation circuit to obtain a coupling coefficient of a primary side coil and a secondary side coil and the size of a load; the duty ratio when the power transmission structure of the wireless power transmission system has the optimal transmission efficiency and output power is obtained through the transmitting side switching tube control structure, control square waves of the E-type power amplifier switching tube are generated according to the duty ratio, the control square waves are sent into the switching tube driving circuit, the control square waves are amplified, and the power transmission efficiency of the E-type power amplifier switching tube is improved. And opening and closing of the switch tube are controlled to complete closed-loop control. The device is simple in structure, high in efficiency, low in cost and wide in application range, and has good practical application value.

The application discloses a kind of continuous high-voltage pulse electric field processing berry functional active ingredient reinforced extraction method.The method comprises the following steps: after the cooling device is cooled to reach the set temperature by the processing chamber device, set high-voltage pulse power output parameter, high-voltage pulse power generates bipolar symmetric square wave, set pulse electric field parameter, the distance of two titanium alloy electrodes is 100mm, the pretreated berry material is transported to the processing chamber body, and the high-voltage pulse electric field processing is carried out on the berry material, to obtain the berry extract containing active ingredient.The method proposed in the application uses continuous round square corrosion-resistant pulse electric field processing chamber, the overall structure is convenient to assemble and process, the processing chamber can be increased according to actual needs, and synchronous cooling can be realized at the same time, the low-temperature extraction and active protection of functional active ingredient are realized while the electrode is protected.

A method for enhanced extraction of functional active ingredients from berries by using continuous high-pulse electric field treatment. The method comprises the following steps: after a treatment chamber apparatus is cooled to a set temperature by means of a cooling apparatus, setting high-pulse power source output parameters; a high-pulse power source generating bipolar symmetric square waves; setting pulse electric field parameters, the distance between two titanium alloy electrodes being 100 mm; conveying pretreated berry materials to the body of a treatment chamber; and performing high-pulse electric field treatment on the berry materials, so as to obtain a berry extraction solution containing active ingredients. In the present invention, a continuous circular-to-square corrosion-resistant pulse electric field treatment chamber is used, such that the overall structure is convenient for assembly and machining; additional treatment chambers can be added according to actual requirements; and synchronous cooling can also be realized, thereby realizing low-temperature extraction and activity preservation of functional active ingredients while protecting electrodes.

The invention discloses an insulation resistance measurement method, a measurement module and an anti-reverse power transmission isolation device, and relates to the field of operation and maintenance of distribution lines, and the key points of the technical scheme are as follows: a control voltage signal is generated according to the voltage demand of the insulation resistance of a test line sent by a user, and a PWM square wave signal with a duty ratio is generated according to the control voltage signal; performing high-frequency voltage transformation and voltage doubling rectification on the PWM square wave signal to obtain a direct-current voltage; calculating a current average value of the measurement loop when each resistance measurement gear is switched; presetting a current coefficient of each resistance measurement gear and weight coefficients of two adjacent resistance measurement gears; and when the current average value is greater than or equal to the product of the current coefficient and the weight coefficient, calculating the insulation resistance value of the measured circuit according to the current average value, the direct-current voltage and the resistance value corresponding to the resistance measurement gear.

The invention discloses an intelligent illumination system for adjusting human body rhythm adaptation, and the system comprises the steps: constructing a parameter regulation and control system which comprises light intensity dynamic adjustment (50-3000lx), spectrum precise configuration (400-780nm continuous adjustment) and time sequence combination control through integrating a phase advance, maintenance and delay three-mode illumination scheme; a mixed modulation mode of superposition of a sine function and a square wave is adopted to realize synchronization of an illumination period and a human body rhythm. The system is equipped with an environment-behavior evaluation module, acquires environment light parameters in real time and constructs an individual time pattern characteristic spectrum, and an intelligent decision-making system automatically selects a working mode according to the environment-behavior evaluation module: starting gradually-intensified blue light intervention during phase delay, keeping light intensity fluctuation to be less than or equal to + / -15% in a stable period, and implementing stepped attenuation regulation and control when a phase is required in advance. An innovatively designed multi-axis projection angle optimization unit (adjustable in 0-90 degrees) is combined with infrared attitude compensation to form an innovative solution of medical level rhythm intervention and human engineering optimization.

The invention discloses a figure rocket launcher pitching transmission shaft torque dynamic detection method and system, and the method comprises the steps: enabling a stepping motor to drive a driving gear through a speed reducer to drive a pitching transmission shaft to rotate, and collecting a torque signal in real time through a magnetoelectric induction torque sensor; and the phase difference measuring unit converts the dual-channel sinusoidal signal into a square wave and calculates the phase difference, and then outputs a digital torque value through the analog-to-digital converter. And the control module adopts Kalman filtering and a calibration curve to realize dynamic compensation. The recording sub-module is provided with a high-capacity solid-state memory and supports continuous recording of detection data in a circulating storage mode. The differential sensing structure is adopted, the neodymium iron boron magnetic steel and the multi-layer winding signal coil design are combined, the detection precision of the micro torque fluctuation under the low-speed and heavy-load working condition is effectively improved, the technical problems of detection lag, transient impact missing detection, data tracing difficulty and the like existing in a traditional method are solved, and the detection precision of the micro torque fluctuation under the low-speed and heavy-load working condition is improved. And the safety monitoring capability of the rocket launcher transmission system is obviously enhanced.

The invention discloses a high-precision BUCK converter with variable time-constant virtual ripple compensation, and relates to the technical field of circuits, a control logic and driving module drives a high-side and low-side switch group according to a control voltage so as to convert an input voltage into a square wave voltage of a switch node, and forwards the control voltage; the LC filter is used for filtering the square wave voltage and outputting steady-state output voltage; the variable time constant ripple injection circuit generates a fixed ripple voltage by extracting an average voltage value of the square wave voltage, and adjusts the size of a time constant by controlling the voltage to generate an alternating current ripple voltage based on the square wave voltage to generate an alternating current compensation ripple voltage; the feedback resistor group divides the output voltage to generate feedback voltage; and the loop comparator compares a superposed voltage obtained by superposing the alternating current compensation ripple voltage and the feedback voltage with a reference voltage to generate a control voltage, so that the high-precision BUCK converter which is simple in structure, high in dynamic response speed and high in steady-state precision is provided.

The invention discloses a non-differential disc type equal-pole common-winding high-power-density motor and a design method, and belongs to the technical field of design and manufacturing of motors and new energy automobiles. The invention discloses a split-disc type high-power density motor and a design method, a double-disc or multi-disc structure is adopted, direct current or alternating current or single-phase alternating current is subjected to physical space nominal phase splitting to complete continuous circumferential rotation or linear motion of the motor, and the specific implementation scheme can be directed at direct current brush motors, direct current brushless motors, direct current brushless motors, direct current brushless motors, direct current brushless motors, direct current brushless motors and direct current brushless motors. Due to the fact that a multi-disc complementary effect is achieved, the number of pole pairs of a rotor and a stator can be equal, the number density of interaction force points of the stator and the rotor in a unit space can be increased, the electromagnetic torque or magnetic resistance torque density can be increased, and square waves can be adopted to replace sine wave currents. The negative torque can be effectively eliminated by timely performing transient outage on the square wave commutation interlaced area, the motor power density can be greatly improved, and the technical scheme is also suitable for the field of generators.

The invention belongs to the technical field of water environment detection, and particularly relates to a heavy metal concentration and water body flow velocity synchronous detection method for a dispersed drain outlet, which is used for synchronously detecting the heavy metal cadmium concentration and the water body flow velocity. The core of the method comprises a three-electrode sensing system consisting of a working electrode coated with a tungsten oxide film, a reference electrode and a counter electrode, and is assisted by an electrochemical workstation, a peristaltic pump, a flow cell and a signal processing module. The cadmium concentration is accurately measured through the square wave anodic stripping voltammetry, the flow velocity is synchronously detected through the open circuit potentiometry, dual-function detection is achieved through integration of the square wave anodic stripping voltammetry and the open circuit potentiometry, synchronous in-situ detection of the cadmium concentration and the water body flow velocity is achieved, and errors caused by measurement position differences are effectively eliminated. The result shows that the cadmium concentration and the dissolution peak current are in a linear relationship, and the water flow velocity logarithm and the open-circuit potential are in a linear relationship. The method designed by the invention is suitable for scattered and small sewage draining exit scenes, and effectively solves the problems of time consumption and equipment redundancy of traditional step-by-step detection. In an actual water sample test, the cadmium recovery rate is 80%-120%, the flow velocity measurement RSD is smaller than or equal to 5.0%, high reproducibility, stability and anti-interference performance are achieved, technical support is provided for real-time online evaluation of the total heavy metal emission amount, and the method has remarkable environmental monitoring application potential.

The invention discloses a method and system for preparing a hard magnesium-aluminum alloy pressing cap through normal-temperature pulse, and belongs to the field of metal-based composite material preparation. The method comprises the following steps: mixing aluminum powder and magnesium oxide particles, and adding a dispersant for ball-milling treatment; applying a bipolar symmetric square-wave pulsed electric field to the mixed powder to achieve a synergistic effect with periodic pulse pressure, polarizing magnesium oxide particles by the electric field, breaking down an oxide layer and performing directional arrangement, and promoting mechanical occlusion of the particles and chemical bonding of an interface by the pressure; and the treated powder is subjected to normal-temperature static pressure forming, cleaning and polishing. The system comprises a raw material processing unit, a pulse compounding unit, a compression molding unit, a cleaning unit, a polishing unit and a control system. The method solves the problems of low interface strength, limited ceramic phase content, poor forming precision and the like of a traditional process, realizes interface chemical bonding and densification at normal temperature, improves the material hardness and structural stability, reduces energy consumption, supports large-scale production, and is suitable for preparation of complex structural members such as precise electronic shielding cases and aerospace fasteners.

The invention relates to a brushless direct current motor simulator system and method. The brushless direct current motor simulator system comprises a motor simulator unit and an energy feedback unit. In the motor simulator unit, a motor resolving model calculates and outputs three-phase current as instruction current based on an input line voltage and a load torque instruction; the motor simulator unit controller takes an interface input side phase current as a tracking current and adopts a current tracking control strategy based on dynamic current deviation compensation to obtain an instruction voltage so as to drive and control a motor simulation power converter; in the energy feedback unit, a phase-locked loop obtains a power grid phase angle based on alternating current side voltage and current; and the energy feedback unit controller generates instruction voltage by adopting a fixed direct current side voltage control strategy based on power grid voltage orientation so as to drive and control the energy feedback power converter. Compared with the prior art, the square wave current and the trapezoidal wave back electromotive force of the brushless direct current motor and the external port characteristics of the brushless direct current motor under normal operation and fault working conditions can be accurately simulated.

This invention relates to a parking braking method and system for maglev trains. The method includes: when the maglev train's speed is at the electro-hydraulic conversion speed point, determining the stage operation sequence according to a corresponding relationship; passing the electro-hydraulic conversion speed point by successively decreasing the stage operation sequence; then acquiring the current state information of the maglev train from the ATO in real time; determining the target deceleration value based on the current state information; determining the stage ratio according to the corresponding relationship and the target deceleration value; applying the stage ratio to the maglev train in a periodic square wave form until the target deceleration value is reached; if the distance between the maglev train and the parking point is a first predetermined distance, then re-determining the target deceleration value; otherwise, when the distance between the maglev train and the parking point is a second predetermined distance, gradually increasing the stage to achieve a fixed-point stop. This invention enables precise stopping of maglev trains under hydraulic braking, ensuring parking comfort and improving the passenger experience.

This invention provides a method and system for controlling the delay time of electronic detonators, comprising: configuring delay values ​​for each electronic detonator via an initiator; sending delay time calibration commands to all electronic detonators and calculating the total duration of the reference square wave of the delay time calibration commands to obtain T0; calculating T1 based on T0; upon receiving the delay initiation command, the electronic detonator calculates and writes the value to a delay timer based on T1, and decrements the timer; after the delay timer of the electronic detonator reaches zero, writing the value of T1mod div to the delay timer and decrementing the timer; and detonating the electronic detonator after the delay timer reaches zero. This invention uses a frequency-division clock to compensate for the delay time error caused by the delay, thus solving the problem of amplified delay time error caused by using only a frequency-division clock.

The present invention discloses a phosphate detection method using a colorimetric method and electrochemical test paper, which belongs to the field of environmental monitoring. Specifically, the phosphate content in the water body is first semi-quantitatively detected by standard colorimetric test paper, and then the electrochemical test paper with a paper base is used to select cyclic voltammetry or square wave pulse voltammetry according to the colorimetric result to detect the phosphate concentration in the water body; when the phosphate content calculated as phosphorus in the colorimetric result is higher than 5 mg / L, the water sample is diluted by half and then detected by cyclic voltammetry; when the phosphate content calculated as phosphorus in the colorimetric result is within the range of 0.5 to 5 mg / L, cyclic voltammetry is used for detection; when the phosphate content calculated as phosphorus in the colorimetric result is lower than 0.5 mg / L, square wave pulse voltammetry is used for detection. The detection process of the present invention does not require the addition of other reagents, has a wide and accurate detection concentration range, and can achieve simple and fast in-situ detection of phosphate.