36results about How to "Ease of engineering practice" patented technology

The invention relates to the technical field of electric transmission and control, in particular to a speed sensor-less method for estimating the rotor angle and the revolving speed of a permanent-magnet synchronous motor. The method comprises the following steps: a. obtaining the rotor flux linkage amplitude Psi<r> of a permanent-magnet synchronous motor; b. transforming a stator voltage fundamental component to be under an alpha beta coordinate system to obtain u<alpha> and u<beta>; c. transforming the stator current fundamental component to be under the alpha beta coordinate system to obtain i<alpha> and i<beta>; d. carrying out highpass filtering on stator current i<alpha> and i<beta> under the alpha beta coordinate system, and obtaining the differential estimation value sum of the stator current; e. obtaining a stator counter electromotive force estimation value; f. obtaining a rotor revolving speed calculation value omega<rC> and a rotor angle calculation value theta<rC>; g. carrying out lowpass filtering on the rotor revolving speed calculation value omega<rC> to obtain a rotor revolving speed estimation value; h. obtaining the estimation value of a rotor angle starting value; and i. obtaining a rotor angle estimation value. The method has the advantages that only forward calculation, instead of a feedback channel, exists in the method for estimating the rotor angle and revolving speed, and except filter delaying, no dynamic regulation process exists.

The invention provides an on-line monitoring method of distribution transformer turn-to turn short circuit. The on-line monitoring method includes the following steps: under the no-load condition, voltage and currents of the high-pressure side of a transformer are obtained, and voltage and currents of the low-pressure side of the transformer are obtained; real-time power losses are obtained according to the voltage and the currents of the high-pressure side and the voltage and the currents of the low-pressure side; the real-time power losses are judged whether to be larger than power losses or not when the transformer works normally; if so, a first alarm signal is sent out, and if not, the first alarm signal is not sent out; and the first alarm signal is uploaded to a control center. The invention provides an on-line monitoring device of the distribution transformer turn-to-turn short circuits. The on-line monitoring device of the distribution transformer turn-to turn short circuit can carry out on-line monitoring in real time and detect failures of the transformer turn-to-turn short circuit timely. Engineering practices are relatively simple, and obvious influences on an original system and structure can not occur.

The invention discloses a structure sharing multi-sensor fusion positioning system for an automatic driving vehicle. The system comprises a vehicle kinematics model module which predicts the motion state of the vehicle according to a vehicle kinematics model; a laser SLAM algorithm module; and an extended Kalman filtering module used for fusing the vehicle prediction pose provided by the vehicle kinematics model and the vehicle optimization pose provided by the laser SLAM algorithm by utilizing the extended Kalman filtering technology so as to obtain accurate vehicle pose information. According to the structure sharing multi-sensor fusion positioning system for the automatic driving vehicle, positioning can be effectively achieved through the arrangement of the vehicle kinematics model module, the laser SLAM algorithm module and the extended Kalman filtering module.

The invention discloses an intelligent comprehensive modeling method for power load digital statistics. The method comprises a non-invasive load monitoring technology. According to the technology, anelectric energy metering device is used for collecting electric load information, deep learning, reinforcement learning and other technologies are used for identifying and classifying user electric loads, a load element model and parameters based on data are formed, and the proportion of energy consumed by a single load element to total consumed energy is calculated. The load element model and theenergy consumption proportion are combined into a load model and the load model is summarized to a bus node, and data such as load element types, parameters and proportions are acquired by adopting methods such as digital statistics and intelligent synthesis. Then, a deep learning algorithm framework such as a production adversarial network generates a power load model and a load discrimination model for accuracy verification of the power load model. The digital statistical intelligent comprehensive modeling method for the power load has the potential of online operation and real-time modeling.

The invention discloses a compound control method for parallel hybrid active power filters, comprising the following steps: (1) acquiring state information of a power grid and a parallel hybrid active power filter; (2) extracting a voltage instruction from the current of the power grid; (3) calculating a voltage error signal; (4) carrying out repetitive control and PI adjustment on a voltage difference signal to obtain a modulation signal; and (5) constructing a PWM signal, wherein the parallel hybrid active power filter includes a passive part and an active part. Through the scheme, the invention can provide a compound control method for parallel hybrid active power filters. In order to overcome the defects of the existing parallel hybrid active power filter controller, a compound control method is provided. A double-loop compound control algorithm, including PI adjustment at the inner loop and repetitive control at the outer loop, is adopted. Odd harmonic, even harmonic and fundamental negative-sequence harmonic can be compensated at high precision. Moreover, the complexity of the system is greatly reduced, the cost is reduced, and the method can be easily used in engineering practice.

The invention discloses a ground cascade system external radio frequency electromagnetic environment test method which includes the steps that one subsystem of a ground cascade system is placed at the testing position of an opening field, other subsystems are arranged, a transmission cable electromagnetic coupling calculation model of the subsystem is constructed, coupling interference current between the subsystem and the other subsystems which are connected with the subsystem is obtained according to the mission cable electromagnetic coupling calculation model, a coupling interference current value curve is built, the coupling interference current is injected to a transmission cable due to the fact that a probe is injected, meanwhile an electromagnetic environment is produced by using a field intensity meter, a power amplifier, a directional coupler, a signal source, a power meter and a radiating antenna, antenna radiation is carried out on the position on the subsystem which is prone to producing an electromagnetic interference coupling by using an the electromagnetic environment, the subsystem is judged whether an electromagnetic sensitive phenomenon happens or not, provided the electromagnetic sensitive phenomenon happens, testing of the ground cascade system is proved to be unqualified, otherwise the testing is proved to be qualified. According to the ground cascade system external radio frequency electromagnetic environment test method, the whole ground cascade system can be tested in the radio frequency electromagnetic environment.

The invention relates to a design process of a shield for resisting electro-magnetic interference in a liquid capacitance type sensor, which comprises firstly determining the frequency spectrum of an interference source needing to be shielded, secondly determining the sensitivity characteristic of the sensor, conducting the sensitivity test for a device which is actually interfered to obtain the sensitivity characteristic curve line, thirdly calculating the round hole size of the shield according to the relative theories of cut-off waveguide, the actual shielding requirements and the working environment request of the sensor, fourthly building a simulation model in a computer, and conducting value emulation calculation, comparing the shielding results, and finally instructing to process real objects according to the calculated results. The invention solves the problem of the electro-magnetic interference of the sensor, and facilitates the sensor to work normally under the electro-magnetic radiation, and the shield which is designed has light weight and excellent oil permeability, and can not affect the normal working.

The present invention discloses a WLAN channel allocation method based on an artificial bee colony algorithm. The method comprises the steps of (1) data acquisition, (2) the establishment of a neighborhood relation matrix and an interference relation matrix, (3) channel allocation determination, (4) the channel allocation based on the artificial bee colony algorithm. According to the method, different channels can be distributed to an access point which generates interference, and thus the throughput of a whole network system and the overall performance of the system are improved.

The invention discloses a unit output optimizing method for improving transient stability margin of a receiving end power grid. According to the method, for the receiving end power grid with a known running state, the transient stability margin of each generator and the sensitivity of transient stability margin to the active output of the unit are calculated, the generator transient stability constraint is used as a constraint condition, a mathematical model of unit output optimization is proposed, and the optimal scheme of each generator output is obtained. According to the method, various operation constraint conditions in the output process of the optimization unit are comprehensively considered, and the output limit value, the limit value of the branch power and the limit value of thevoltage amplitude of a node are considered, so that the adaptability of various operation modes of the system is high, engineering practical operation is easy, and the transient stability characteristic of the generator can be ensured to meet the expected condition by optimizing the unit output.

The invention provides a method for improving methane fermentation activity of methanol, and belongs to the technical field of methane fermentation of organic wastewater. According to the invention, a quorum sensing signal molecule, namely, N-hexanoyl homoserine lactone (C6-HSL), is added into a methanol methane fermentation system to regulate and control a microbial quorum sensing signal system, so that the group metabolic activity of methanogens can be effectively improved, the methanol degradation rate and the methane production rate are further improved, and the economic benefit of methanol wastewater methane fermentation is improved.

The invention relates to the technical field of fiber-optic gyroscopes, in particular to a multi-parameter simulation platform for measuring the temperature characteristic of an optical fiber ring, and the platform can be used calculate a thermal drift error of a fiber-optic gyroscope more completely. The system comprises a parameter input module, a result display module and a program control module, and is characterized in that the parameter input module comprises a basic parameter, a solving parameter, a simulation parameter, a temperature control condition simulation parameters and a variable temperature condition simulation parameter of the optical fiber ring. Due to dual analysis based on the Shupe effect and the photoelastic effect, the thermal drift error of the fiber-optic gyroscope can be calculated more completely; the configuration parameters of light paths and circuits are added, so that a random walk coefficient of noise can be calculated according to the configuration parameters; and according to the fact, the effect on the thermal drift error of the fiber-optic gyroscope when the outermost side of the optical fiber ring is not fully wound can be fully considered.

The invention provides a method for evaluating the dynamic risk failure possibility of mobile pressure-bearing equipment, and the method comprises the steps: constructing a dynamic risk failure possibility evaluation model of different units of the mobile pressure-bearing equipment (I-type long tube trailer) based on a quantitative and qualitative failure possibility evaluation system of a failure mode; the failure possibility evaluation system comprises the influence of the equipment body state, the equipment service status and the enterprise management level on the failure frequency. The method can evaluate the equipment failure probability. The method comprises the following steps: firstly, obtaining design, installation, operation and maintenance files of the mobile pressure-bearing equipment; carrying out data arrangement on all influence factors, and preprocessing to complete a comprehensive inspection report; dividing the moved pressure-bearing equipment into units, and calculating a failure possibility score; and comprehensively calculating the risk value of each pipe section, dividing risk levels, and analyzing weak links and key factors which influence the overall safety of the equipment.

The invention relates to the technical field of electric derive and control, in particular to a without-speed sensor estimation method for a high-accuracy permanent magnet synchronous motor. An estimation process is finished in an estimation rotation reference system with rotate speed being wx and with a phase angle being thetax. The method comprises the steps of firstly, conducting low-pass filtering for a rotate speed calculated value through a formula, obtaining a rotate speed estimation value, eliminating an algebra loop on the rotate speed, meanwhile, finishing estimation of a rotor angle initial value through a formula, then, combining a formula, finishing estimation of an angle through the fact that estimation of the rotor angle initial value is added to an angle integral value, and finally adopting and updating the rotate speed and the phase angle of the estimation rotation reference system so that influence due to a high-pass filtering step is reduced, and therefore estimation accuracy is improved. The without-speed sensor estimation method for the high-accuracy permanent magnet synchronous motor has the advantages of being conducted in the rotation reference system. Compared with an estimation method in a stationary coordinate system, the without-speed sensor estimation method for the high-accuracy permanent magnet synchronous motor is smaller in influence due to the high-pass filtering step, and therefore the estimation accuracy is higher.

The invention discloses a vehicle-mounted navigation positioning performance debugging method based on a whole vehicle electromagnetic environment. The method comprises the following steps: collecting whole vehicle electromagnetic environment noise; establishing a noise database and quantitative indexes; the noise data index curve is optimized through an algorithm, and different parameters are adjusted; based on the optimized noise parameters, the antenna position is adjusted, and a navigation positioning terminal, a whole vehicle navigation positioning test and a whole vehicle navigation whole vehicle road training test are carried out. According to the method, an algorithm is creatively used for optimizing the noise data index curve to adjust and optimize the noise parameters, the position of the antenna is adjusted so as to obtain the vehicle navigation and positioning performance under different parameters, and a basis and a direction are provided for vehicle navigation and positioning performance optimization under the vehicle electromagnetic environment.

The invention provides a polyethylene buried pipe risk evaluation method.Based on GB/T27512 and aiming at polyethylene pipe characteristics, polyethylene pipeline scoring weights are reconstructed, failure factors and corresponding scoring rules are increased,a new failure possibility evaluation method is provided The method comprises the following steps: firstly, obtaining design, installation and completion files of an evaluated pipeline, and line patrol along the way and field survey and excavation measurement data; carrying out data arrangement on all influence factors, and preprocessing to complete a comprehensive inspection report; based on an analytic hierarchy process and an expert scoring method, calculating weights of third-party damage, corrosion and aging, equipment (devices) and personnel operation and intrinsic safety factors of the polyethylene pipe; dividing the evaluated pipeline, completing scoring according to scoring rules, and calculating a failure possibility and a failure consequence score according to a pipeline scoring result; and comprehensively calculating the risk value of each pipe section, and dividing risk levels.