133results about How to "Prevent overcharge and overdischarge" patented technology

The invention relates to an optical storage alternating current and direct current hybrid micro-grid system and a control method of the system. The system and the method are characterized in that a hybrid micro-grid comprises an alternating current micro-grid subsystem, a direct current micro-grid subsystem and a power exchange control system; the alternating current micro-grid subsystem comprises an alternating current side photovoltaic power generation unit, an alternating current load and a grid-connected interface; the direct current micro-grid subsystem comprises a direct current side photovoltaic power generation unit, a storage battery energy storage unit and a high / low voltage direct current load; the power exchange control system comprises a two-way AC / DC power converter, a transformer, a micro-grid controller and a communication system, the storage battery energy storage unit is used for controlling direct current bus voltages, and P / Q control is adopted in the two-way AC / DC power converter. Under the stabilizing effect of direct current side energy storage, the direct current micro-grid subsystem conducts photovoltaic power generation and is connected to a large power grid through the alternating current micro-grid subsystem at constant power, and the photovoltaic utilization rate is increased. By means of the control method, the power supply reliability and economical efficiency of the hybrid micro-grid are effectively improved.

The invention discloses a modification-based state-of-charge estimation method for an RC battery model. The modification-based state-of-charge estimation method comprises the following steps: building an RC modification model; identifying parameters of the model; utilizing the extend Kalman filter (EKF) algorithm to obtain a continuous state space function of the battery RC modification model; according to the battery model parameter values of all points SOCs, acquired by the identification method, performing repeated curve fitting; then using the interpolation method to acquire the parameter values of the SOCs in the whole stage. The invention provides the EKF battery state-of-charge estimation method based on the RC modification model by the built RC modification model to overcome the defects of the classical battery state-of-charge estimation algorithm. Compared with a traditional method, the modification-based state-of-charge estimation method has the characteristics of favorable dynamic performance, insensitivity to initial value errors, excellent measurement noise inhibition property and the like.

The invention relates to a distribution network peak load shifting distributed energy storage power distribution and coordination control method which comprises the steps that (1) the total adjusting power of distributed energy storage system peak load shifting is determined; (2) a power distribution strategy of a similar distributed energy storage system is determined; (3) power distribution strategies of a distributed mixed energy storage system at different time scales are determined; and (4) the distributed mixed energy storage system is subjected to coordination control. Distribution network peak load shifting is achieved, the peak valley difference rate meets the requirement, charging-discharging power distribution and control based on an energy-storage system real-time state are achieved, over charging and over discharging are avoided, coordination control of different kinds of energy-storage systems is achieved, and the adjusting requirements of different network distribution time scale loads are met.

The invention discloses a hybrid energy storage system and a wind power generation power smooth control method. Firstly, a frequency spectrum of a wind power signal is obtained through a quick Fourier method, and amplitude-frequency characteristics of wind output power are analyzed; then, wind power is decomposed in multiple scales through an empirical mode decomposition method and then reconstructed into wind farm expected grid-connection power and high-frequency, mediate-frequency and low-frequency wind power fluctuation power; the power is distributed according to the capacity of a super-capacitor Soc, correspondingly adjusted and absorbs high-frequency, mediate-frequency and low-frequency fluctuation signal power through the super-capacitor, a storage battery and stored compressed air energy; when the output power of a wind farm is smaller than an expected grid-connection power signal, a hybrid energy storage system composed of the super-capacitor, the storage battery and an CAES is controlled to discharge through a model algorithm; when the output power of the wind farm is larger than expected grid-connection power, the hybrid energy storage system composed of the super-capacitor, the storage battery and the CAES is controlled to charge through the model algorithm. The hybrid energy storage system and the wind power generation power smooth control method improve safety and economic efficiency of grid-connection operation.

The invention discloses a capacity allocation method for a hybrid energy storage system capable of restraining wind power output power fluctuation. The wind power fluctuation component is extracted based on the national wind power integration standard by means of the improved moving average method, fluctuating power is allocated by means of the variable-filter time constant high-pass filtering method based on the charging states of energy storage equipment, in this way, over-charging and over-discharging of energy storage equipment can be avoided, and finally a capacity allocation model is established with the full-life circle economical efficiency optimization of energy storage equipment as an objective function. Compared with a traditional method according to which only one-time primary investment is considered, the method better accords with the actual condition of long-term operation of an energy storage system and has guiding significance for practical engineering construction.

The invention belongs to the field of energy storage of electric system micro-grids, and particularly relates to an energy storage subsystem used for a batch-type renewable energy source power generation system and a control method of the energy storage subsystem. The energy storage subsystem used for the batch-type renewable energy source power generation system comprises independent storage batteries, bidirectional DC power conversion devices, a storage battery charging and discharging controller, a storage battery state monitor device, an energy storage system concentrated control device and a connection line. By the utilization of all the storage batteries, instantaneous power balance between the batch-type new energy resource power generation and electric loads is finished, the utilization rate of resources is improved to the maximum extent, the idle waste of the storage batteries is avoided, the performance of the storage batteries is effectively protected, and the service life is prolonged.

The invention provides a control method of a cell energy storage system inhibiting renewable energy output power fluctuation. The control method is characterized in that: based on a low pass filtering principle, through a first order Butterworth filter, a renewable energy output power value is subjected to filtering, a renewable energy output power object value is obtained, by utilizing charge and discharge control of the cell energy storage system, a difference between the renewable energy output power object value and a renewable energy output power measured value is compensated, and a purpose of inhibiting the renewable energy output power fluctuation is achieved. According to the invention, based on a basic filtering principle, by utilizing a good renewable energy output power inhibition effect and adding of an SOC (state of charge) feedback link, over charge and over discharge of a cell are avoided, innovation is carried out, when adding the SOC feedback link, through adjusting a size of a filtering time constant, an output power of the energy storage system is changed indirectly, thus when inhibiting the inhibiting the renewable energy output power fluctuation, the over charge and over discharge of the cell are effectively avoided, stable operation of the cell energy storage system is maintained, and a service life of the cell is prolonged.

The invention relates to a power driving system architecture in a hybrid vehicle. A battery module in a motor power driving sub system is connected with a first driving motor / generator through a first motor control module; the first driving motor / generator is connected with a power coupling transmission device; an engine control module in an engine power driving sub system is connected with an engine; the generator is connected with the battery module through a second motor control module; and the engine is connected with the power coupling transmission device through the generator. The invention also relates to a method for realizing power driving control in the hybrid vehicle based on the system architecture. By adopting the power driving system architecture in the hybrid vehicle and the control method for the power driving system architecture, the system architecture is more rational, the vehicle has higher power performance, and driving is higher in flexibility and completeness; furthermore, the vehicle saves energy, is environment-friendly and has high safety coefficient; and the power driving system architecture is stable and reliable in working performance and wider in applicability range, and lays a firm foundation for popularization and application of a hybrid technology.

The invention provides an isolated island microgrid real-time schedule energy management system which comprises an energy management unit, a real-time monitoring unit, a prediction control unit and a distributed unit circuit breaker. A microgrid comprises power generating units, a battery and a load, wherein the power generating units, the battery and the load are respectively connected with a power bus through a power converter. The real-time monitoring unit acquires the running state of each power generation unit and the battery. The prediction control unit predicts the output power and the load demand of each power generation unit according to current weather information data and historical load data. According to received microgrid running data and prediction result data, the energy management unit calculates the running state and the output power of each power generation unit of next time by taking the minimum system running cost as an objective function and safe system running as a constraint condition. Accordingly, the distributed unit circuit breaker controls each power generating unit to transmit power to a power grid. According to the invention, the influence of uncertain factors of weather conditions, load fluctuations and the like on the running of the system can be reduced, and the running reliability of the microgrid is improved.

The invention discloses an energy storage SOC optimization control method in a wind storage system. According to predicted power of a wind power farm in a period of time in the future, a particle swarm algorithm is used for solving an SOC optimization model to obtain the optimal SOC range of an energy storage system in the running process of the wind storage system; according to real-time charge states, the charge state migration proportion relative to the optimal SOC range is obtained, the charge state migration proportion and the set power at the current moment of the energy storage system are used as input, a filtering time constant is used as output, a fuzzy control strategy is used for adjusting the filtering time constant in real time, and grid-connection power is stabilized through low-pass filtering of real-time power of the wind power farm. According to the energy storage SOC optimization control method, the SOC of the energy storage system is adjusted in advance according to the predicted power of the wind power farm, therefore overcharging and overdischarging phenomena are avoided, and the output power of the wind power farm is smoothened for a long time.

The invention relates to the technical field of new energy vehicle energy management and specifically relates to an energy management method of a vehicle-mounted fuel battery hybrid power system. Theenergy management method of the vehicle-mounted fuel battery hybrid power system comprises the following steps of 1, establishing a hybrid power system model; and 2, considering a demand power changerate and an effect of a lithium battery SOC on the basis of the hybrid power system model established in the step 1 so as to manage energy of the hybrid power system. According to the energy management method of the vehicle-mounted fuel battery hybrid power system, the change rate of load demand power is considered in the hybrid power energy management method; by adding the vehicle working condition information, the performance of the hybrid power system can be better on the one hand, and the vehicle operation working condition applicable to the method is wider on the other hand. According tothe energy management method of the vehicle-mounted fuel battery hybrid power system, during determining an actual current of a lithium battery, a maximum charging and discharging current of the lithium battery is restricted to prevent overcharging and over-discharging of the lithium battery. According to the energy management method of the vehicle-mounted fuel battery hybrid power system, an additional control current is calculated through fuzzy control according to a current lithium battery SOC state so that the lithium battery SOC is kept within a reasonable interval.

The invention discloses a V2G charger adopting high-frequency chain matrix converter and a control method thereof. The V2G charger comprises a grid-side filter, a high-frequency chain matrix converter, a single-phase bridge-type full control rectifier, and a battery side filter, wherein the high-frequency chain matrix converter comprises a three phase-single phase AC / AC matrix converter and a high-frequency transformer T; and the grid-side filter, the three phase-single phase AC / AC matrix converter, the high-frequency transformer T, the single-phase bridge-type full control rectifier, and the battery side filter are sequentially connected. the V2G charger control method comprises steps of charging and feeding; and according to charging and feeding, outer loop switching control is adopted to generate an outer loop control quantity, the outer loop control quantity is subjected to inner loop decoupling control to obtain pulse signals, and the pulse signals are used for controlling the high-frequency chain matrix converter for realizing charging or feeding. The V2G charger adopting high-frequency chain matrix converter has the advantages of simplified structure, high conversion efficiency, small size and small weight, stable charging and feeding control, and good battery protection.

The invention relates to a power battery management system of an electric vehicle. The power battery management system comprises a battery management system control board and a plurality of single battery information acquisition boards, wherein the battery management system control board and the single battery information acquisition boards are connected through RS232 buses for information interaction; the battery management system control board comprises an embedded processor, an RS232 communication module, a CAN bus communication module, a battery pack current acquisition module, a USB communication module, a touch screen human-computer interaction module, an Ethernet communication module, a battery balancing control module and an audible alarm module; and each single battery informationacquisition board comprises an embedded processor, a digital isolator, an RS232 communication module, a single battery voltage acquisition module and a single battery temperature acquisition module.The power battery management system of the electric vehicle is easy to mount and connect by virtue of the modular design. The accuracy of voltage and current acquisition is high and the estimation ofremaining battery power is accurate. The power battery management system of the electric vehicle has a battery balancing function to prevent the battery from being over-charged and over-discharged, and prolongs the service life of a power battery.

The invention relates to the technical field of energy storage system droop control of a DC micro-grid, in particular to a method for maintaining voltage division curve dynamic droop control of a micro-grid bus in an energy storage link. The method comprises dividing the energy storage link into a system stable non-working zone, an energy storage charging / discharging control blind zone, and an energy storage charging / discharge dynamic droop control zone; for the energy storage charging / discharge dynamic droop control zone, using battery SOC-based and virtual impedance dynamic droop control; for the energy storage charging / discharging control blind zone, determining curve droop control of an exponential function according to the coordinates of the intersection point and the function derivability of the energy storage charging / discharging control blind zone and the energy storage charging / discharge dynamic droop control zone. The control method designs and determines the control flow ofthe energy storage link in combination with the two characteristic working zones, expands the control range of the energy storage link, fundamentally solves the power distribution of the energy storage link, enables the output power finally to tend to be equal, compensates for a voltage drop difference caused by the droop control, makes the system operate stably.

The invention discloses a composite cathode material of a sodium-ion battery. The composite cathode material is characterized by comprising a core part and a sheath coating the surface of the core part. The core part is made from a compound shown in the formula (i), that is Na2MnPO4F (i), and doped with amorphous carbon. The sheath is made from a compound shown in the formula (ii), that is Na3V2(PO4)2F3 (ii) and doped with amorphous carbon. The weight ratio of the compound shown in the formula (i) to the compound shown in the formula (ii) to amorphous carbon is (10-95):(3-90):(0.1-20). The provided composite cathode material of a sodium-ion battery is good in structural stability and cycling performance.

The invention discloses an optimization method of active distribution system dispatching in industrial parks considering the demand of peak load regulation. The photovoltaic power generation unit PV,the vanadium flow battery energy storage system VRB and the industrial load are used as the active distribution system dispatching units in the industrial park, which participated in the considering of peak load regulation, and the physical models of each dispatching unit are established. The DTMDP model is established to solve the dynamic dispatching optimization problem of active distribution system in industrial parks considering the demand of peak load regulation. The Q-learning algorithm based on simulated annealing is used to solve the DTMDP model, and the optimal control strategy is used to guide the system to choose the reasonable action plan in the actual operation process and realize the system scheduling optimization. The invention can effectively solve the problem of peak shaving demand of the power network under the condition of considering the randomness of the source and the load, promote the local absorption of new energy, and improve the operation economy of the activedistribution system and the operation stability of the power system.

The invention aims to provide an energy management method of a hydrogen fuel cell hybrid electric vehicle. The energy management method comprises the following steps of 1), establishing an energy management system model of the hybrid electric vehicle, 2) collecting data of the hybrid electric vehicle under different working conditions, processing the data by utilizing a nearest neighbor method toobtain a universal demand power transfer probability matrix, and then obtaining an optimal hybrid electric vehicle energy management strategy by taking an energy storage system SOC and a total hydrogen consumption ECMS as learning targets, and 3) based on the hybrid electric vehicle energy management system model established in the step 1), combining the change rate of the required power and the SOC data of the lithium battery and the super capacitor, performing frequency division decoupling through an adaptive fuzzy low-pass filter, and performing energy management on the hydrogen fuel cell hybrid electric vehicle. The continuous space energy management strategy based on deep reinforcement learning has higher universality and real-time performance.

The invention provides an equalizing current control method for an H-bridge cascaded energy-storing system and belongs to the technical field of battery energy storage. The H-bridge cascaded energy-storing system employs carrier phase-shifting modulation. All sub modules use successively-shifted triangular carriers and respective modulating waves. According to the state of charges (SOC) of batteries measured by a battery management system (BMS), the optimum charging current of the batteries is acquired and respective given power instructions are acquired. Finally, the given modulating wave amplitudes of the sub modules are allocated according to the proportions of the power instructions to a total power instruction, thereby controlling the current of the battery pack in an equalized manner. The equalizing current control method prevents overcharging and over-discharging of the battery pack, improves the utilization rates of the batteries, and prolongs the service lives of the batteries.

Provided is a micro remote wild animal tracker and a control method thereof. The micro remote wild animal tracker comprises a solar cell, an improved MPPT control circuit, a lithium battery, an energy efficiency management module, a communication module, a microprocessor, a satellite positioning module, a highly-reliable data management module, a system never-failing monitoring module, and an ephemeris data hot backup module. The solar cell charges the lithium battery with the improved MPPT control circuit. The microprocessor performs further energy efficiency management on the lithium battery with the energy efficiency management module. The system never-failing monitoring module prevents a system from dead halting. The highly-reliable data management module saves important parameter setting data of the system. The microprocessor communicates with the satellite positioning module via a RS232 interface. The micro remote wild animal tracker has characteristics of waterproofness, a small size, light weight, and super low power consumption, may operate in high altitude, high temperature, and low temperature environment, and can be by widely used for tracking and positioning wild animals.

With regard to the problem of overcharge and over-discharge due to different initial states-of-charge (SOC) of a DC microgrid during the process of system power supplement or absorption of a pluralityof energy storage units and the defect that the load current of an energy storage system cannot be reasonably allocated in real time by a traditional droop control method, a novel storage SOC index function-based droop control method is research and developed. The difference from a traditional method lies in that a droop coefficient can be changed in real time according to the change of the SOC index function, so that the storage battery SOC and the load current reach a balance state, and the effects of equally dividing the load and prolonging the service lifetime of the storage battery are finally achieved.

The invention relates to the technical field of a lithium battery, in particular to a low-temperature self-heating and high-temperature heat-dissipation overcharge-overdischarge prevention winding-type lithium battery. The lithium battery comprises an anode, a cathode and an injection hole, and also comprises a heat dissipation window, a state display instrument, a battery shell, phase change layers, a control block, concentrators, a heating cylinder, a winding group and fans, wherein the heat dissipation window and the state display instrument are arranged on the side wall of the battery shell, the heat dissipation window is provided with a temperature sensor, the state display instrument is provided with a red alarming lamp and a green alarming lamp, the lower end of each concentrator is provided with a SOC sensor, the winding group is arranged inside the heating cylinder, two ends of the heating cylinder are provided with the fans, two ends of each fan are provided with the concentrators, and the phase change layer is arranged between each fan and the battery shell. The lithium battery is applicable to various temperature conditions, can perform self-heating at a low temperature, and can dissipate heat automatically at a high temperature, the overcharge and overdischarge of the battery can be prevented to protect the application performance of the battery and prolong the service life of the battery, and thus the lithium battery is a lithium ion battery with powerful functions.

The invention relates to a charging and discharging dynamic voltage-balancing circuit which is applied to a power supply composed of multiple cell units which are connected in series. In the process of discharging the power supply, when a first transistor is on, the power supply charges the cell units with relatively low voltage out of the multiple cell units on a priority basis and enables the multiple cell units to reach balanced voltage; while in the process of charging the power supply, when a third transistor is off, a primary winding, the first transistor and the power supply form a BUCK follow current loop, so as to charge the cell units with relatively low voltage out of the multiple cell units on a priority basis and enable the multiple cell units to reach balanced voltage. The invention also relates to a power supply using the charging and discharging dynamic voltage-balancing circuit. In the invention, through the relation of an original secondary winding of the transformer, Ton time slot in the discharging process of a BOOST circuit and Toff time slot in the charging process of the BUCK circuit are effectively utilized to carry out dynamic voltage balancing on the cell units which are connected in series in the power supply.

Disclosed is a method of estimating a maximum output of a battery for a hybrid electric vehicle (HEV). The method comprises steps of: extracting maximum charge / discharge outputs of the battery depending on a plurality of charged states (SOC) of the battery under which the vehicle is able to be driven and calculating an interrelation between them; extracting maximum charge / discharge outputs of the battery at plural temperatures under which the vehicle is able to be driven, and calculating an interrelation between them; extracting degradations of outputs of the battery as a capacity of the battery is discharged during the traveling, and calculating an interrelation between them; and based on the interrelations obtained from each of the steps, estimating a maximum output (Powermax) of the battery through a following function. Powermax=F⁡(SOC,temp,accumulated⁢ ⁢ ⁢discharge⁢ ⁢Ah)=F⁡(SOC,temp)⨯F⁡(accumlated⁢ ⁢discharge⁢ ⁢Ah)

The invention relates to a wireless charging system of an unmanned aerial vehicle and a charging control method thereof. The system includes ground platform end and unmanned aerial vehicle end. The ground platform end comprises a box, a first communication module, a first control module, an electric energy transmitting coil, a proximity sensor, an actuating mechanism and a shielding layer. The UAVterminal comprises an UAV, a second communication module, a second control module, an electric energy receiving coil, a voltage detecting module, a UAV battery and a rectifying circuit. The inventionhas the advantages that the voltage detection module is utilized to measure the voltage of the battery of the unmanned aerial vehicle in real time, the charging and discharging of the battery of theunmanned aerial vehicle is effectively controlled through the first and second communication modules and the first and second control modules, and the overcharging of the battery of the unmanned aerial vehicle can be prevented. The problem of concentric coupling of power transceiver coil is solved effectively by using actuator, which avoids the problem of inaccurate positioning and landing of UAV,and improves the efficiency of power transmission of coil. The elastic snap ring plays the role of fixing the UAV and avoids the influence of external force during field operation.

The invention discloses an external energy storage unit and LC quasi-resonance-based battery pack equalization circuit. The circuit of the invention comprises a series-connected battery pack, a gating switch, an equalizing bus, an LC series quasi-resonant unit, a buck-boost unit, an external energy storage unit, a voltage detection circuit and a controller; n energy storage batteries are connected in series so as to form the series-connected battery pack; the gating switch includes 2n bidirectional controllable switches; the positive poles and negative poles of the energy storage batteries are respectively connected with the positive pole and negative pole of the equalization bus through the bidirectional controllable switches; the equalization bus is connected in series with the LC series quasi-resonant unit, the buck-boost unit and the external energy storage unit sequentially; the controller is connected with the gating switch and the LC series quasi-resonant unit; and the voltage detection circuit detects the voltage signals of the energy storage batteries and the buck-boost unit and transmits the voltage signals to the controller. With the equalization circuit and method of the invention adopted, the battery pack can be equalized actively, fast and efficiently, the overcharging and over-discharging of the batteries can be prevented, and the consistency of the batteries can be improved.

The invention relates to a lithium battery bidirectional inverter energy storage power device, which comprises a device shell, and is characterized in that a lithium battery component is arranged in the device shell, wherein an output end of the lithium battery component is connected with an input end of an LCD (Liquid Crystal Device) electric quantity display component; and an output end of the LCD electric quantity display component is connected with an input end of a bidirectional inverter. Meanwhile, a loop between an output end of a charging module of the bidirectional inverter and the input end of the lithium battery component is provided with a charging switch; a loop between an input end of an inverter circuit module of the bidirectional inverter and an output end of the lithium battery component is provided with a discharge switch; and the bidirectional inverter is provided with a mains supply input port and an inverter output port. Thus, over-charging, over-discharging, over-current and over-high temperature can be prevented, and the safety in use is guaranteed. By using modularized design, the lithium battery bidirectional inverter energy storage power device has a small integral size and is suitable for energy storage power systems of medium and small-sized enterprises and household power systems.

The invention relates to an improved control method for a multi-energy storage independent DC microgrid of considering mismatched line resistance for achieving SOC balancing of various battery energystorage units in the microgrid. The improved control method is characterized by comprising the following steps of (1) adding multiple groups of battery energy storage units which are connected in parallel and are equal in capacity to a DC bus in a DC microgrid structure; (2) building an improved droop control model for the multi-energy storage independent DC microgrid of considering the mismatchedline resistance; and (3) feeding differences between an ESOC average value and an output current average value in a current sampling period and current ESOC values and output current values of the battery energy storage units into a sampling holder separately according to the improved droop control model and then modifying a reference voltage offset in real time according to the output result ofthe sampling holder, thereby achieving SOC balancing of the battery energy storage units. Compared with the prior art, the improved control method has the advantages of considering the mismatched lineresistance and avoiding over-charging and over-discharging.

The invention discloses a method for limiting charging and discharging power of a power battery. The method comprises the following steps of: acquiring working parameters of a power battery, working parameters of a driving motor and driving parameters of a whole vehicle in real time; determining the limit torque of the motor; determining output backup power when the power battery is discharged or input backup power when the power battery is charged according to the working parameters of the power battery; determining a motor capability limiting torque according to the working parameters of the driving motor; determining an expected required torque of a driver according to the whole vehicle driving parameters; comparing the output backup power with a backup power preset value or comparing the input backup power with the backup power preset value, and determining the actual demand torque of the driver according to the comparison result, the motor limit torque, the motor capability limit torque and the expected demand torque of the driver. According to the invention, the phenomenon that the required power of the power system is not matched with the capacity of the power battery can be avoided, and the phenomenon of long-time over-charging and over-discharging of the power battery in the use process can be avoided.

The invention discloses a wind and light storage power generation system coordination control method considering load and wind and light volatility, which comprises the following steps of: predicting the load by using a multi-dimensional dense network algorithm to obtain a predicted load curve; establishing a prediction model of the wind and light storage power generation system, considering the volatility of a wind power and photovoltaic power generation system and the charge state of energy storage, constructing a coordinated optimization model of the wind and light storage power generation system, and solving the optimal number combination of photovoltaic units and fans at each moment, so that the wind and light storage power generation system can effectively track and predict a load curve. According to the coordination control method, the energy storage charge and discharge depth can be reduced, energy storage overcharge and overdischarge are prevented, meanwhile, the fluctuation of wind power and photovoltaic output power is reduced, the load tracking capacity of the combined power generation system is improved, and the method has a feasible practical value and a wide application prospect.