58results about How to "Less control variables" patented technology

The invention discloses a T-shaped three-level inverter, and discloses the input / output relation of all units and the functions of each unit in detail. The invention also discloses a neutral-point balance control method for the T-shaped three-level inverter based on voltage differential prediction. The method overcomes the limitations of a neutral-point balance control method based on zero sequence voltage injection in the prior art, i.e., a zero sequence voltage component being one or zero. Although the adjustment speed is high, a system is liable to lose control and the stability of the system is not facilitated. Moreover, there are more variables in conventional detection, and the calculation burden of a computer is heavy. The method is small in number of collected signals, and the speed of reduction of neutral-point voltage fluctuation is high. The method is low in hardware cost, is simple in program, is small in calculation burden, is high in practicality, is high in robustness, and can guarantee the full-range work stability of the inverter.

The invention discloses bearing-free switch reluctance motor having an axial-direction parallel hybrid structure and a control method of said motor. A motor stator is composed of a reluctance motor stator and a magnetic bearing stator. A rotor is composed of a salient pole rotor and a cylinder rotor. The windings are composed of torque windings and suspension windings. The torque windings are composed of reluctance motor windings and wide-tooth windings and the number of the torque windings is identical to phase number m. The suspension windings are two and are arranged in the radial direction. The magnetic bearing stator is composed of four E-shaped structures and the width of each middle tooth is twice of the rest. According to the invention, suspension current is calculated according to a suspension force direction. Current of the torque windings and switching-on and switching-off angles of a power circuit are controlled separately and rotation speed and torque are controlled in real time. Current of the two suspension windings is controlled separately, suspension forces are regulated in real time and mutual decoupling is realized in rotation and suspension. According to the invention, the quantity of control variables is small; suspension control is simple; and a power converter of a suspension system is low in cost.

The invention provides a reactive voltage optimal control method for a wind power plant cluster. The reactive voltage optimal control method comprises the steps that whether the reactive voltage optimal control for the wind power plant cluster needs to be carried out or not is judged; the reactive source equipment adjustment range of wind power plants and a pooling station in the wind power plant cluster region is obtained; and a reactive voltage optimal control mathematic model for the wind power plant cluster is built and solved. According to the reactive voltage optimal control method, a wind power plant cluster access point is used as a central voltage control node, the wind power plant grid-tied point bus voltage of the cluster region and a transformer tap of a booster station of the wind power plant are regulated, reactive compensation equipment of the pooling station is regulated to have reactive power, and a transformer tap of the pooling station is also regulated, the pilot node is enabled to meet the control instruction range of a dispatching mechanism, meanwhile the quiescent voltage stability margin of the cluster region is enabled to be maximum, and the active power transmission loss is enabled to be minimum; the quiescent voltage stability margin in the wind power plant cluster region can be effectively improved, the grid active loss in the cluster region also can be reduced, the operating safety and stability of a system are improved, and the capacity of digesting and saving wind power of the system is also improved.

The invention discloses a control method of a composite rotor bearingless switched reluctance machine. A stator of the machine is of a salient pole structure and is provided with twelve stator teeth, each stator is only provided with a set of winding, a rotor comprises a salient pole rotor and a cylindrical rotor, the cylindrical rotor is used for generating a suspension force, and the salient pole rotor is provided with eight teeth and is used for generating a torque; in a suspension excitation section, four windings of each phase are independently controlled and are equivalent to a main winding and two suspension windings, and a calculation method of a main winding current and suspension winding currents with minimum winding copper loss is adopted; and in a torque excitation section, the four windings of each phase are jointly controlled, and the rotational speed and the torque are controlled in real time by controlling a chopping limit and a turn-off angle of a phase winding current. By the method, the torque control and the suspension force control are decoupled, coordination control is performed, the high-speed suspension property is good, the control variable is reduced, simple control and convenient implementation are achieved, and the copper loss in the suspension section is small.

The present invention discloses a taper magnetic bearing switched reluctance motor and a control method thereof. The motor is composed of a switched reluctance motor and two taper magnetic bearings; the bias windings of the two taper magnetic bearings are connected in series with the winding of the switched reluctance motor to a form m-phase torque winding; two vertical suspension windings of each taper magnetic bearing are configured to control the suspension with two degrees of freedom, have four vertical degrees of freedom and are able to perform decoupling control; the axial suspension windings of the two taper magnetic bearings are connected in series to form an axial suspension winding for controlling the axial suspension; the motor is able to independently control the opening and closing angles of a torque winding current and power circuit to control the rotating speed and the torque in real time; and the motor is able to control five suspension winding currents to regulate the suspension forces in five directions so as to realize the suspension with five degrees of freedom. The taper magnetic bearing switched reluctance motor and the control method thereof are small in control variables, simple in suspension control and low in cost of a suspension system power converter.

The invention discloses a two-degree-of-freedom dual-winding hybrid magnetic bearing switched reluctance motor and a control method thereof, and belongs to the field of a magnetic suspension motor and control thereof. The motor comprises a 12 / 8-pole switched reluctance motor and a 12-pole magnetic bearing, wherein a suspension winding and a bias winding are wound around each of four stators of the magnetic bearing, all bias windings are connected and then are connected in series with an A-phase winding of the reluctance motor to form an A-phase composite excitation winding, a constant conduction excitation mode is employed, bias magnetic flux is generated in the magnetic bearing, and meanwhile, a torque is generated in the reluctance motor; a B phase and a C phase employ modes of excitation in turns, and the A phase employs asymmetric excitation in a positive and negative half period to generate an effective torque; and the A phase provides the bias magnetic flux by control and also generates an average torque equal to those of the other two phases, and the average output torques output from the three phases are symmetric. By the motor and the control method, the magnetic bearing and the reluctance motor are isolated, no coupling is generated between magnetic paths, the torques and the suspension forces are decoupled, and a power system is low in cost and is simple to control.

The invention discloses a three-degree-of-freedom mixing conical and radial magnetic bearing, and belongs to the field of magnetic suspension bearings. The three-degree-of-freedom mixing conical and radial magnetic bearing is composed of a radial magnetic bearing body and a conical magnetic bearing body; an axial magnetization annular permanent magnet or annular bias winding is arranged between the radial magnetic bearing body and the conical magnetic bearing body to provide biased magnetic flux; a radial magnetic bearing stator is of a salient pole structure and provided with four teeth; each stator tooth is wound with a coil, and every two coils are connected to form two radial suspension windings; a rotor is of a cylinder structure; the conical magnetic bearing body comprises two conical stators and two conical rotors which are each of a conical cylinder structure; an axial suspension winding is embedded between the two conical stators; the radial stator, the two conical stators and the permanent magnet are connected through a magnetic conductive ring; and the radial rotor and the two conical rotors are sleeved with a rotor magnetic conductive ring and then a rotary shaft. Control magnetic circuits of the radial magnetic bearing body and the conical magnetic bearing body are isolated, axial force and radial force are decoupled, control is simple, the structure is compact, the three-degree-of-freedom mixing conical and radial magnetic bearing can be applicable to electromagnetic bearings or permanent magnetic bias type magnetic bearings, and universality is good.

The invention discloses a five-degree-of-freedom co-excited bearing-less switched reluctance motor system and a control method. The system is composed of a switch reluctance motor, a hybrid magnetic bearing and a radial magnetic bearing, wherein bias windings of the two bearings and an m-phase armature winding of the switch reluctance motor share the same set of power converter; with the adoptionof a co-excited manner, biased magnetic flux is generated in the two bearings when torque is generated in the switch reluctance motor; the m-phase armature winding adopts the traditional switch reluctance drive mode; and the current of the bias winding is only related to working conditions of the switch reluctance motor, and no control is performed. In addition, current of five suspending windingsis reasonably controlled by combining with the current of the bias winding collected in real time, so that five-degree-of-freedom suspension operation can be realized. According to the system disclosed by the invention, suspension force is decoupled, the suspension force and the torque are also decoupled, the control variable is less, the suspension control is simple, the integration level is high, the reliability is high, no permanent magnet exists in the system, the environmental suitability is high, and the system has unique advantages in high-speed or ultra-high-speed application occasions.

The invention discloses an axial-radial electrically-excited magnetic bearing. Stators of the magnetic bearing comprise E-shaped stators and C-shaped stators, wherein rotors comprise radial suspension rotors and axial suspension rotors; windings comprise a bias winding, an radial suspension winding and an axial suspension winding; the radial suspension winding comprises two suspension windings in radial direction; both the number of the E-shaped stators and the number of the C-shaped stators are 4; the middle tooth width of each E-shaped stator is two times to that of other two teeth; the radial suspension rotors and the axial suspension rotors are cylindrical structures; the bias winding is capable of simultaneously providing radial bias magnetic flux and axial bias magnetic flux; the radial suspension winding is capable of controlling radial suspension; the axial suspension winding is capable of controlling axial suspension. Through the axial-radial electrically-excited magnetic bearing, the axial suspension force and the radial suspension force are decoupled with each other; two radial suspension forces are also decoupled with each other; magnetic circuits are isolated from one another; the magnetic bearing is high in fault-tolerance performance, few in control variables, simple to control and few in power circuits.

The invention discloses a conical magnetic suspension dual-passage switch reluctance machine and a control method. The machine comprises a switch reluctance machine and two conical magnetic bearings, wherein a bias winding of each conical magnetic bearing is connected in series with a passage winding of the switch reluctance machine to form a three-phase torque winding, two radial suspension windings of each conical magnetic bearing control suspension of two degrees of freedom, total four radial degrees of freedom exit, radial suspension forces can be in decoupling control, and a torque and axial suspension are further controlled by currents of two passage windings of the switch reluctance machine. By the switch reluctance machine and the control method, an axial suspension winding is not needed independently, suspension of five degrees of freedom can be achieved, the machine system is high in integration, a few in control variable and high in redundancy, and is simple to control.

The invention belongs to the technical field of nano-material preparation and concretely relates to a graphene oxide and graphene oxide quantum dot solvothermal controllable preparation method and a use thereof. The preparation method comprises that common graphite as a raw material is added with a certain amount of sulfuric acid and potassium permanganate, the mixture is stirred for some time, the mixed solution is added with nitric acid, the suspending liquid is transferred into a Teflon reactor, the mixture undergoes a solvothermal reaction, the reaction product flavescent transparent liquid is dispersed in deionized water, a certain amount of the solution is subjected to dialysis until pH is 7 so that the graphene oxide or graphene oxide quantum dot aqueous solution is obtained in a dialysis bag, and the aqueous solution is subjected to freeze drying so that graphene oxide or graphene oxide quantum dot powder is obtained. In preparation, the graphene oxide or graphene oxide quantum dot can be produced only by control of a reaction temperature and graphene oxide quantum dots with different particle sizes can be obtained by change of a ratio of graphite to potassium permanganate. The preparation method utilizes one-step solvothermal method, has simple operation and after-treatment processes, and has a short period, a low cost, no toxicity and no pollution. The produced material can be widely used in fields of photoelectric devices, anti-counterfeiting, biomolecule fluorescence labeling and bioimaging.

The invention discloses a five degrees-of-freedom conical magnetic levitation switch reluctance motor and a control method. The motor consists of a three-phase 12 / 8-pole switch reluctance motor and two conical magnetic bearings; the bias winding of one conical magnetic bearing and two windings in the A phase horizontal direction of the switch reluctance motor are connected in series while the biaswinding of the other conical magnetic bearing and the two windings in the A phase vertical direction are connected in series to form two channel A phase composite windings; a constant switch-on strategy is adopted to generate bias magnetic flux of the two magnetic bearings and to generate torque in the reluctance motor; the B and C phase winding structures in the switch reluctance motor in the motor are the same as that of the conventional switch reluctance motor, so that alternate excitation switch-on is performed to generate torque to realize rotary operation; by only controlling the current of the A phase two sets of windings and the current of four radial levitation windings, five suspension force can be controlled to realize the five degrees-of-freedom levitation; and the motor is high in system integration degree, high in magnetic utilization rate, simple in control and convenient to implement.

The invention discloses a hybrid radial conical magnetic bearing switch reluctance machine and a control method. The machine comprises a switch reluctance machine, two radial magnetic bearings and two conical magnetic bearings, wherein one of the radial magnetic bearings and one of the conical magnetic bearings are arranged at one side of the switch reluctance machine, the other two bearings are arranged at the other side of the switch reluctance machine, bias windings of four magnetic bearings are connected in series with a winding of the switch reluctance machine to form an m-phase torque winding, torque control is the same as a traditional control mode of the switch reluctance machine, five directional suspension forces are only related to a current of the m-phase torque winding and a current of each directional suspension winding, the suspension forces are decoupled to one another, and the torque and the suspension forces can be in decoupling control. The machine and the control machine are high in integration, a few in control variable and simple in suspension control, and a suspension system power converter is low in cost.

The invention discloses a five-degree-of-freedom electromagnetic-type magnetic suspension switched reluctance motor and a control method. The motor comprises an electromagnetic-type axial and radial magnetic bearing, a switched reluctance motor and an electromagnetic-type radial magnetic bearing. The switched reluctance motor generates torque to realize rotary operation; the electromagnetic-type axial and radial magnetic bearing generates two radial suspension forces and one axial suspension force, and the electromagnetic-type radial magnetic bearing generates two radial suspension forces, sothat five-degree-of-freedom suspension operation is realized; the bias windings of the two magnetic bearings and the m-phase armature winding of the switched reluctance motor are jointly excited by apower converter, and the torque and bias magnetic flux are generated at the same time. According to the motor and the control method, the electromagnetic conversion efficiency is high, the system integration level and reliability are high, and comprehensive integration of the motor, the magnetic bearing and the control system is achieved; the torque control method is the same as a method of a traditional switch reluctance motor; five suspension winding currents are controlled to adjust five suspension forces, so control variables are few, the control is easy, the suspension power loss is small, and suspension precision is high.

The invention discloses a four-degree-of-freedom composite structure bearingless switch reluctance machine and a controlling method thereof. The motor is composed of a switch reluctance machine and two radial magnetic bearings. Each magnetic bearing stator is formed by four E-type structures; one suspension winding and one armature winding wind around a middle tooth of each E-type structure; and one bias winding and one armature winding wind around two tooth windings. One armature winding winds around each tooth of the switch reluctance machine and crosses over the two magnetic bearing stators and a switch reluctance machine stator. An A-phase armature winding forms one phase; and B-phase and C-phase armature windings and bias windings are connected in series to form another two phases. A torque controlling way is identical with a traditional switch reluctance machine controlling way. The suspension force at a certain direction of each magnetic bearing is only related with a three-phase armature winding current and a suspension current at the direction; and the torque and the suspension force as well as the torque and the radial suspension force is in decoupling controlling. The suspension controlling becomes simple; and the outputs of the suspension forces are balanced and symmetric.

The invention discloses a conical magnetic suspension switch reluctance motor and a control method. The motor consists of a switch reluctance motor and two conical magnetic bearings; bias windings of the two conical magnetic bearings are connected with a winding of the switch reluctance motor in series to form a three-phase torque winding; two radial suspension windings of each conical magnetic bearing control suspension of two degrees of freedom, so that four radial degrees of freedom is formed and decoupling control can be realized; the axial suspension windings of the two conical magnetic bearings are connected together in series to form one axial suspension winding to control axial suspension; the motor can independently control torque winding current and turn-on and turn-off angles of the power circuit, and can control rotary speed and torque in real time; current of five suspension windings is controlled, suspension force in five directions can be adjusted in real time, and suspension of five degrees of freedom can be further realized; and the motor and the control method disclosed by the invention are high in integration degree, less in control variables and simple in suspension control, and the power converter of the suspension system is low in cost.

The invention discloses a technology for carrying out electrocatalytic oxidation treatment on chemical nickel wastewater. The technology is characterized by taking an inactive metal oxide compound electrode as an electrode, forming intermediate products such as hydroxyl radicals with strong oxidizing properties through catalysis under the action of an electric field, enabling the intermediate products to react with an inorganic or organic ligand of nickel, and oxidizing the inorganic or organic ligand into micromolecules such as carbon dioxide and water or oxidizing the inorganic or organic ligand into orthophosphate radicals, thus achieving the purpose of 'decomplexation'. The technology disclosed by the invention has the characteristics that an oxidizing agent requires not to be added, reaction conditions are gentle, the decomplexation effect is good, the running cost is low, the system is simple, stable and reliable, the automation degree is high, and the like.

The invention discloses an electromagnetic bearing switch magnetic resistance motor system and a control method. The motor system comprises a switch magnetic resistance motor, a three-DOF magnetic bearing and a radial magnetic bearing. Bias windings of the two magnetic bearings are connected in series and are then connected with DC buses of asymmetric half-bridge power converters of m phase armature windings of a switch magnetic resistance motor through four diodes, the m phase armature windings employ a traditional switch magnetic resistance driving mode, under the rectification effect of thefour diodes, a continuous invariant current is generated in a bias winding to provide bias magnetic flux for the two magnetic bearings; through reasonable control on currents of the five suspension windings, five-DOF suspension operation can be realized, mutual decoupling among five suspension forces is carried out, and decoupling between the suspension forces and torques is carried out. The motor system is advantaged in that the integration degree is high, the dynamo-electric energy conversion utilization rate is high, control variables are in a small quantity, suspension control is simple,reliability is high, the motor system has no permanent magnet, so working environment adaptability is strong, and the motor system is especially suitable for high-speed or super-speed application occasions.

The invention discloses a mixed magnetic bearing dual-winding switch reluctance motor and a control method. The motor consists of a switch reluctance motor and two radial magnetic bearings; a magnetic bearing stator is formed by four E-shaped structures, and the middle tooth of each E-shaped structure is wound with a suspension winding; each tooth of the switch reluctance motor is wound with a bias winding and a reluctance motor winding separately; the bias winding transversely crosses two magnetic bearing stators and a switch reluctance motor stator while the reluctance motor winding only winds the reluctance motor stator; two windings are connected in series to form a torque winding string, and a three-phase torque winding can be formed; the torque control is the same as the control way of the conventional switch reluctance motor; the suspension force in two directions of each magnetic bearing is only related to the three-phase torque winding current and two suspension currents, and decoupling control of the torque and the suspension force can be realized; the motor and the control method disclosed by the invention are high in integration degree, less in control variables and simple in suspension control, and the suspension power converter is low in cost; and design of decoupling control of the torque and the suspension force can be realized.

The invention discloses an electrocatalytic oxidation treating method and system of cyanide-containing wastewater. An inactive metallic oxide with catalytic ability is adopted as an electrode, intermediate products of hydroxyl radical and the like with strong oxidizing property are formed through catalyzing under the electric field action, and the cyanide in the cyanide-containing wastewater reacts with the intermediate products to be oxidized into micromolecules of carbon dioxide, nitrogen, water and the like, thereby achieving the purpose of cyanide breaking. The electrocatalytic oxidation treating method and system of cyanide-containing wastewater has the advantages that feeding of an oxidizing agent is not needed, reaction conditions are mild, cyanide is removed thoroughly, operation cost is low, the system is simple, steady and reliable, the degree of automation is high and the like.

The present invention discloses a taper magnetic bearing switch reluctance motor and a control method thereof. The motor is formed by one switch reluctance motor and two taper magnetic bearings; a taper stator is formed by 4 E-shaped structures, the central tooth of each E-shaped structure is winded with a vertical suspension winding, is winded at, each of other two teeth are respectively winded with an axial direction suspension winding, the vertical suspension windings and the axial direction suspension windings are connected in series to form a set of the axial direction suspension winding; an armature winding crosses the two taper stators and a reluctance motor stator to form 3-phase armature winding; rotation control is the same as a traditional switch reluctance motor control mode, and bias flux is generated for suspension; and five suspension forces are associated with the 3-phase armature winding current, current of 4 vertical suspension windings and current of 2 vertical suspension windings; the two vertical suspension windings can optimize the bias flux to allow the generated bias flux to be equal when the 3-phase armature winding performs individual excitation so as to solve the problem that the vertical suspension force output is unbalance. The motor system is high in integration degree and high in current utilization rate and realizes decoupling between the torque and the suspension force.

The invention discloses an optimal Bingham number control method for the impact working condition of an automobile electric control damping suspension system, and the method depends on hardware including the automobile electric control damping suspension system, a displacement sensor and a force sensor. The method comprises the following steps: 1) establishing an automobile suspension system dynamic model under an impact working condition according to mechanical characteristics of an automobile suspension in a stretching and compressing state; 2) calculating the motion state of the electrically-controlled damping suspension under impact excitation by utilizing the kinetic model and the initial conditions of suspension control, and calculating the optimal Bingham number and the corresponding expected force in the compression and springback process; 3) based on the multi-operator model, establishing a nonlinear mechanical model of the automobile electric control damping actuator; and 4) tracking the expected force through an electric control damping actuator nonlinear mechanical model, and calculating the optimal output power matched with the optimal Bingham number. According to the invention, the self-adaptive control of impact buffering can be quickly and accurately realized, so that the structural damage of impact excitation to a vehicle body / frame structure and a driver and passengers can be effectively reduced.

The invention relates to an aggregate grading design method for improving the strength of a cement-emulsified asphalt mixture. The method comprises the steps of determining multiple stages of screen hole sizes of target gradation, a grading upper limit corresponding to each stage of screen hole sizes, and a grading lower limit corresponding to each stage of screen hole sizes; carrying out linear fitting to obtain a straight line I: Log P upper (x)=a Log (x / xmax)+b, and a straight line II: Log P lower (x)=c Log (x / xmax)+d; making n+1 straight lines with slopes which are respectively K1, K2, K3, K4, K5,... and Kn+1; making grading curves which respectively correspond to the n+1 straight lines, and determining the best grading curve from the grading curves. The method involved in the invention avoids idealized conception in the traditional method, and is closer to practical engineering application.

The invention discloses a converter flue gas sample gas dry pretreatment method based on thermal-state sampling, which solves the problems of sampling head damage, blockage and the like in the existing sampling process, and adopts the technical scheme that high-temperature converter flue gas is led out from a converter evaporation cooling flue through a flue gas sampling port and enters a sample gas pretreatment unit to be subjected to pretreatment such as cooling and purification; the high-temperature converter flue gas is fed into a mass spectrometer or an infrared analyzer for flue gas analysis for flue gas composition analysis, and the high-temperature converter flue gas is in reverse direct contact with the solid particle medium packed bed in the sample gas pretreatment unit for heat exchange, and is filtered and intercepted by a solid particle medium layer of the solid particle medium packed bed to obtain the high-temperature converter flue gas. And most smoke dust particles carried by the high-temperature converter smoke are captured. The method provided by the invention has the advantages of maintenance-free system, compact structure and high cooling efficiency, and can realize continuous and stable operation of the sampling process.

The invention discloses a method for solving an SEVM model problem based on an artificial bee colony algorithm. The method comprises the steps of firstly, establishing a model; secondly, performing analgorithm flow of the artificial bee colony algorithm; thirdly, solving a random expected value function flow by using a random expected value estimation algorithm of random simulation, and finally,providing specific steps for solving the SEVM model problem by combining the artificial bee colony algorithm and random simulation and experimental data comparison of typical simulation examples. According to the invention, a solving method which is more effective than the classical genetic algorithm is provided for solving the SEVM model problem; the algorithm has the characteristics of strong global convergence and optimization capabilities, high solving speed, high solving quality and the like due to a search strategy combining local search and global search, the method fills the blank ofapplication research of the artificial bee colony algorithm in a stochastic programming problem, and has a certain practical value; and meanwhile, an idea is provided for efficient solving of other uncertain planning problems.

The invention belongs to the technical field of special steel plate preparation, and particularly provides a ferrite-martensitic double-phase hot-rolled pickling plate for wheel spokes and a preparation method thereof, the ferrite-martensitic double-phase hot-rolled pickling plate comprises the following components by weight: 0.05-0.07% of C, 0.40 to 0.60% of Si, 1.20% to 1.50% of Mn, less than orequal to 0.020% of P, less than or equal to 0.010% of S, 0.020%-0.070% of Alt, 0.30% to 0.40% of Cr, 0.10% to 0.20% of Mo, less than or equal to 0.006% of N and balance of Fe and unavoidable impurities. The ferrite-martensitic double-phase hot-rolled pickling plate adopts lower chromium and molybdenum contents, reduces the alloy cost, adopts a lower silicon content, reduces the difficulty of continuous casting production after steel making, improves the heat dissipation capacity and continuous casting ability of molten steel, and is beneficial to industrial mass production. By adopting of a two-stage cooling process, control variables are reduced, the operability and stability of the production are improved, and the coiling temperatureis appropriately increased to (350-400 DEG C). The higher the temperature, the lower the strength of the steel, and the loss of coiling equipment is reduced.

The invention discloses an intelligent control method for the steam quantity and the cavity temperature field of an electric steamer. An evaporation heater, an auxiliary heater and a temperature sensor are arranged in the electric steamer. The method comprises the following steps: S1, acquiring the maximum allowable use power of the evaporation heater and the target temperature and the cooking time in the current working mode; S2, starting an evaporation heater and adjusting power by adopting a PID algorithm to obtain average power; S3, operating at the actual use power and adjusting by adopting a PID algorithm, when the operation time reaches the cooking time, ending cooking, and otherwise, executing S4; and S4, judging whether the current temperature in the cavity reaches the target temperature or not, if so, returning to execute S3, otherwise, starting the auxiliary heater, adjusting and correcting the actual use power of the evaporation heater by adopting a PID algorithm, and returning to execute S3. According to the method, accurate control over the steam amount and the temperature field is considered, the water utilization rate is increased, overflow and dry burning are avoided, the experience feeling is good, the development period is short, cost is low, and universality is good.