74results about How to "Guaranteed power balance" patented technology

The invention discloses a minimum equivalent fuel consumption-based hybrid electrical vehicle control method, which comprises the following steps of: acquiring a nominal equivalence factor offline; acquiring signals; identifying working conditions; performing adaptive regulation; and performing optimum control. Under the condition of meeting the requirement of dynamic property, the minimum equivalent fuel consumption-based hybrid electrical vehicle control method is adopted, adaptive regulation can be performed according to an actual working condition, and the electric quantity balance of a storage battery is ensured, so that the performance and service life of the storage battery are ensured. The nominal equivalence factor is acquired through simulation calculation in the offline state, and calculated quantity for real-time control of the whole vehicle is reduced. In addition, different from a global optimal control method in which a future vehicle running working condition is required to be known (the future vehicle running working condition is unpredictable actually), the method has high implementability; and by the method, the real-time optimal energy management decision can be provided, the fuel economy of the whole vehicle is further improved, and the emission is reduced.

The invention relates to a power scheduling operation method, in particular to a wind-fire-water co-scheduling method on the basis of a multi-agent system. The method solves the problem that a conventional power scheduling operation method cannot meet the requirement on the large-scale wind power grid-connected operation. The wind-fire-water co-scheduling method on the basis of the multi-agent system is implemented by adopting the following steps of: 1, constructing a wind-fire-water co-scheduling model on the basis of the multi-agent in a scheduling Agent; 2, acquiring predicted data of a load demand in a power system by a load Agent in the power system; 3, sending acquired basic data and real-time data into the wind-fire-water co-scheduling model on the basis of the multi-agent by each thermal power Agent; and 4, issuing and executing a scheduling command by each thermal power Agent and a hydroelectric Agent. The wind-fire-water co-scheduling method is suitable for large-scale wind power grid-connected operation scheduling.

The invention relates to a microgrid hybrid energy storage system and a control method thereof. The system comprises a power grid, wherein the power grid is connected with a microgrid common ac bus, the microgrid common ac bus is connected with a first subcircuit bus and a second subcircuit bus through microgrid energy management systems respectively, and the microgrid common ac bus is also connected with the first subcircuit bus through a transformer TM4; the microgrid common ac bus is also connected with the first subcircuit bus through a transformer TM5; the first subcircuit bus is connected with a lithium battery energy storage module, a super-capacitor energy storage module and a lead-acid cell energy storage module; the second subcircuit bus is connected with a load module. A microgrid internal energy storage system and loads are predicted, internal energy storage devices and loads are optimized and controlled during grid-connected operation, isolated network operation and state switching of a microgrid according to an energy storage power source and load characteristics, system output is smooth, and then intermittency and volatility of renewable energy sources are effectively inhibited.

The invention discloses an input split type hybrid power flow control method and relates to the technical field of vehicle hybrid power. The method comprises, based on the input split type rotating speed and rotating torque coupling relationship, enabling an engine to be in a rotating speed control mode, and a generator and an electromotor to be in a rotating torque control mode; starting from the target power of a battery pack and a driving required power and based on an optimal fuel economy working curve, determining the working points of the engine, the generator and the electromotor, and meanwhile, ensuring the balance between electric quantity and power of batteries. According to the input split type hybrid power flow control method, firstly, the driving required power and the target power of the battery pack are determined, so that under the premise of ensuring vehicle dynamic performance, the regulating manner of the generator and every electromotor can be determined according to the characteristics of a input split type hybrid power system and accordingly the working points of every power unit can be adjusted flexibly, and further the fuel economy can be enhanced; through power flow control, the power and the electric quantity of the batteries can be in a reasonable state, over-charging or over-discharging of the batteries can be avoided, the system performance can be improved and the service life of the batteries can be prolonged.

The invention discloses a control method of a railway power regulator based on a half-bridge structure. The railway power regulator based on the half-bridge structure is composed of two half-bridge arms, and the two half-bridge arms are connected with each other by two capacitors. Since the voltage at the DC side is powered by two series capacitors, the problem of voltage sharing exists. In orderto realize voltage sharing at the DC side, a voltage sharing PI regulator is used for controlling the deviation of the two capacitor voltages, and the offset output by the voltage sharing regulator directly influences the charging and discharging current of the two capacitors, thereby reducing the deviation to 0. In order to keep the voltage at the DC side stable, the voltage external ring at theDC side uses a PI controller to regulate the output value, and the output value is respectively multiplied by the synchronizing signals of the two power supply arms, and superposed by the harmonic and negative sequence compensating current reference signal obtained by computation according to the VV traction system negative sequence and the harmonic compensation principle, thereby obtaining the current reference signal of the two half-bridge converters. In order to realize quick tracking of internal ring current, a hysteresis control method is used for the output currents of the two converters, so that the currents from the output ends of the two converters track the reference compensating signal, thereby realizing negative sequence and harmonic compensation.

The invention discloses a multi-mode coordination control method of an annular AC / DC hybrid microgrid system. The annular AC / DC hybrid microgrid system is characterized in that an AC side and a DC side form a looped network structure through two AC / DC bidirectional converters, and the AC side and the DC side are radiation type networks respectively; in the annular AC / DC hybrid microgrid system, the voltage class of a medium-voltage alternating-current bus is 10 kV, the voltage class of the medium-voltage direct-current bus is + / -1.5 kV, the alternating-current side is connected with a large power grid and comprises a wind driven generator, a micro gas turbine, an alternating-current load and an alternating-current side energy storage system, and the distributed power supply and the load are connected with the medium-voltage alternating-current bus through an alternating-current transformer, the direct-current side comprises a photovoltaic power generation system, a direct-current loadand a direct-current side energy storage system, and the distributed power supply and the load are connected with a medium-voltage direct-current bus through a direct-current transformer.

The invention relates to a data processing method and a data processing device for hybrid networking. The data processing method comprises the following steps: processing an MIMO user data and a non-MIMO user data to acquire a first input data borne on a main pilot channel and a second input data borne on an auxiliary pilot channel, wherein the first input data comprises the non-MIMO user data; performing mapping processing of balanced power on the first input data and the second input data to acquire a first output data and a second output data borne on radio-frequency channels; and sending the first output data and the second output data to a forward emission channel. The method and the device map two paths of data comprising MIMO and non-MIMO user data in a base band to the radio-frequency channels to effectively ensure power balance of two radio-frequency channels by adjusting the power on the premise of ensuring the MIMO and non-MIMO user receiving performance.

The invention discloses an asynchronous constant speed wind turbine system for a micro grid and a working method thereof. The system comprises a wind wheel, a gear box and an asynchronous generator connected in sequence. The asynchronous constant speed wind turbine system for the micro grid also comprises a wind power-side circuit breaker, and one end of the wind power-side circuit breaker is connected with a stator side of the asynchronous constant speed wind turbines and the other end is connected with an isolation transformer. The isolation transformer is connected with an AC / DC / AC converter, the AC / DC / AC converter is connected onto a wind turbine substation via a grid-side circuit breaker, the wind turbine substation is connected onto an AC bus, and a grid-connected circuit breaker is also arranged between the AC bus and the grid. Wind power fluctuations are stabilized, power balancing and stability of the overall system when the micro grid works are maintained.

The invention relates to an APFs and SVCs combined power quality control method based on a micro-power grid energy storage system. A micro-power grid busbar is connected with an energy storage system,loads, SVCs and a distributed power supply device; the energy storage system is composed of a PCS and an energy storage battery, and the energy storage battery achieves energy exchange with the micro-power grid through the PCS and outputs a proper amount of active power and reactive power to ensure the power balance of the micro-power grid from the system level, so that the system voltage and frequency are maintained relatively stable; the PCS is connected to the micro-power grid busbar; the loads include the linear load and the non-linear load, and both loads are connected to two branches through the corresponding SVCs respectively; the distributed power supply device includes a solar photovoltaic plate and a wind power generation device, and the solar photovoltaic plate and the wind power generation device are connected to two branches through corresponding parallel-type APFs respectively. Through overall coordinated use of the energy storage system, the APFs and the SVCs, the battery energy storage system not only can effectively maintain the power balance of the micro-power grid, but also can improve the power quality of the micro-power grid, and the stable operation of the system in various states is achieved.

The invention discloses a photovoltaic cluster access-based AC / DC power flow section coordination and optimization control method, comprising the following steps: introducing a switching function, establishing a nonlinear characteristic-based AC / DC power flow section mathematical model composed of a plurality of current converters on the basis of a nonlinear characteristic-based AC / DC power flow section mathematical model of a single current converter, a dynamic expansion method and coordinate transformation; constructing a power coordination and optimization controller to realize rational distribution of AC / DC power flow section transmission power and primary regulation on DC bus voltage; constructing a voltage recovery optimization controller to perform recovery control on the DC bus voltage, so as to realize secondary regulation on the DC bus voltage and improve dynamic response characteristics of the DC bus voltage. According to the photovoltaic cluster access-based AC / DC power flow section coordination and optimization control method disclosed by the invention, power fluctuation can be stabilized quickly, internal power balance of an AC / DC hybrid microgrid can be maintained, the respective current converters can be enabled to have optimized dynamic response characteristics while coordination control on a plurality of parallel-operated current converters is realized; not only can zero dynamic asymptotic stability be ensured, but also optimization control on the dynamic characteristics of the current converters can be realized.

The invention relates to the technical field of nuclear power station steam turbine auxiliary systems, and provides a nuclear power control system and a nuclear power control method. The system comprises a steam turbine power control system and a reactor power control system; the steam turbine power control system controls steam turbine active power of a steam turbine function unit; the reactor power control system controls reactor power by controlling a power bar and a temperature bar of a reactor function unit; the reactor power control system receives key parameters coming from the steam turbine power control system and representing steam turbine control, and the key parameters are coordinated with reactor power control. The control method has a steam turbine power control system powerclosed loop control mode and a pressure limiting mode. The technical scheme is applied to a nuclear power station unit, GRE-RGL control is stable, the condition of steam turbine load shedding or nuclear island overpowering is avoided, and reactor-steam turbine power transient state control stability and reactor power balance are achieved.

The invention relates to a micro-grid frequency adjustment control method and system. When a micro-grid is operated in an off-grid isolated island mode, distributed measurement elements are used for measuring voltage, frequency and power real-time signals in real time, and the signals are uploaded to a computer; the computer is used for analyzing and processing the uploaded signals; when output power of a power supply is greater than a load power, a signal for reducing the output power of the power supply is sent out; when the load requirement cannot be met, a signal for removing a certain unimportant load is sent out; distributed power supply power control equipment or load control equipment acts respectively according to the signals sent by the computer, and the frequency adjustment of the micro-grid is realized. With the adoption of the micro-grid frequency adjustment control method and system disclosed by the invention, the equipment capable of quickly releasing energy can release energy instantaneously at the moment that the micro-grid is operated in an off-grid isolated island mode, rapid fluctuation of voltage and frequency is suppressed; and when the micro-grid is stably operated in an off-grid isolated island mode, frequency stabilization of the micro-grid is maintained by controlling the output power of the distributed power supply and removing the load, so that the power generated by the power supply of the micro-grid is balanced with the power among the loads of the micro-grid.

The invention discloses a voltage equalizing control method for a cascaded two-stage inverter. The voltage equalizing control method for a cascaded two-stage inverter includes the steps: performing fine adjustment on the duty ratio through error per unit correction to perform voltage stabilization control, on the basis of a cascaded two-stage inverter model, for a DC bus voltage drift problem caused by uneven illumination; obtaining the fine adjustment amount of the duty ratio through a series of adjustment of a PI adjustor after error voltage per unit for each module, and realizing voltage equalizing control of the DC bus by adjusting the duty ratio of each module; and providing a specific implementation mode for fine adjustment of the duty ratio through carrier phase shift modulation, and establishing a 3-cell cascaded two-stage inverter models in the MATLAB / Simulink software. The simulation results show that the control strategy of the voltage equalizing control method for a cascaded two-stage inverter can achieve stable tracking under the condition of uneven illumination and suppress bus voltage drift.

The invention provides a bipolar MMC convertor station control system for an offshore wind power grid and a control method of the bipolar MMC convertor station control system. The system comprises anonshore bipolar MMC convertor station connected to an onshore alternating current system and an offshore bipolar MMC convertor station connected to an offshore wind plant, wherein the onshore bipolarMMC convertor station is connected to the offshore bipolar MMC convertor station; the onshore bipolar MMC converter station comprises positive and negative MMC converters which are respectively connected to the onshore alternating current system and are controlled by constant direct current voltage and constant reactive power; and the offshore bipolar MMC converter station comprises positive and negative MMC converters which are respectively connected to the offshore wind plant, and adopts a master-slave control strategy with power balancing capacity. The system and the method have the advantages that a stable synchronous alternating current power supply can be provided for the offshore wind plant, and the mutual influence between the positive and negative bipolar MMC converters is avoided.

The present invention discloses a trigger control method for the reactive power adjustment event of a power system. The method comprises the steps of 1) measuring and monitoring the tidal current state signal of a power grid in real time; 2) filtering the signal obtained in the step 1) to obtain a tidal current state signal; 3) processing the signal obtained in the step 2) and conducting the A / D conversion of the signal to obtain a digital signal; 4) calculating the difference between the digital signal and a real-time power grid tidal current state expected value; 5) introducing a lyapunov function, proving the stability of the system, and confirming that the state of the system can be converged to the expected value; 6) according to conclusion of the step 5), designing a method for the event trigger control of the system, and determining an event triggering condition; 7) calculating the event triggering condition of the formula 6), and triggering an event if the condition is met; 8) repeatedly executing the step 7). The invention further discloses a system adopting the above method. The method and the system have the following advantages: the power balance of the power system is ensured; the operation stability and the operation quality of the power system are improved; and the adjustment consumption and the communication cost of the system are reduced maximally.

The invention discloses a method of controlling power balance among multiple driving points of a sealing-tape machine. The method mainly comprises the steps of selecting a reference motor, conducting torque regulation and processing including torque comparison, torque deviation calculation, torque amplitude limiting and torque biasing based on the selected reference motor, and setting input conditions of a motor based on a torque regulation and processing result. By means of the method of controlling power balance among the multiple driving points of the sealing-tape machine, the defects of large labor amount, low production efficiency, short service life of the sealing-tape machine and the like in the prior art can be overcome, so that the advantages of small labor amount, high production efficiency and long service life of the sealing-tape machine are achieved.

The invention discloses a natural gas power station direct current micro-grid hybrid CPU multiple bidirectional DC port device and implementation method thereof and relates to a natural gas power station direct current micro-grid bidirectional DC port device, the natural gas power station direct current micro-grid bidirectional DC port device is used for solving the problems of the existing natural gas engine set that the dynamic response is slow, the non load and unbalance load supported by the inverter import a lot of even order fundamental frequency harmonic, the quality of electric energy of the direct current micro-grid is reduced, the natural gas generator capacity is consumed and the system efficiency is reduced. The natural gas power station direct current micro-grid bidirectional DC port device comprises a DSP instruction calculating module, a FPGA logic signal processing module, a multiple DC / DC power conversion module, a detecting and protecting module, a control sampling and signal setting module, a CAN bus communication module and an energy storing module; the device adopts the control method as follows: the master / slave mode compensation control, isolated mode energy storing surplus capacity balance compensation control and direct current bus DC port harmonic suppression control. The device is used for offering the power for natural gas power station in a bidirectional mode.

The invention provides an islanding method based on an energy constraint and belongs to the field of power management; the method comprises the following steps of determining energy parameters in a to-be-divided island; establishing an optimal islanding model of each photovoltaic power storage station in a power grid system based on an energy constraint condition; solving the established optimal island model to obtain an island range corresponding to each optical storage station; carrying out fusion treatment on the intersected island ranges so as to obtain islands without intersection; carrying out power dispatching verification on the obtained islands without the intersection; if the power dispatching verification is passed, the island range is output and islanding is finished. The powerbalance of each time period during island operation is guaranteed through the power dispatching verification in the islands. The model in the method is a linear model and can be solved through maturecommercial software; compared with a heuristic model and method, the method in the invention has higher solving speed and higher global optimization capability.

The invention discloses a bilateral participation-based peak regulation auxiliary service capacity selection and economic model building method. Firstly, system information of a day-ahead region is obtained and serves as input data of a peak regulation auxiliary service capacity selection and economic model; by building a scheduling model of deep peak regulation resources in a bilateral participation mode, simulation operation is carried out on the peak regulation capacity condition of a called conventional unit; correction is carried out according to correction rules of a peak regulation capacity proportion under the same price; the income and expenditure of each power generation enterprise and the electricity abandonment rate of new energy are calculated; and result calculation is carried out. A new idea of "bilateral participation" of the new energy and the thermal power unit is proposed; a new development idea is provided for calling the peak regulation auxiliary service resources;and the calling of a peak regulation auxiliary service is modeled, so that the peak regulation resources can be reasonably called, and new energy consumption can be promoted.

The invention relates to an energy coordination control method of an off-grid direct-current microgrid. The direct-current microgrid is provided with a photovoltaic power generation unit, a wind powergeneration unit, an energy storage unit and a load unit. The direct-current microgrid is divided into a plurality of working modes according to the grade of the direct-current bus voltage, in each working mode, one or more units of the photovoltaic power generation unit, the wind power generation unit, the energy storage unit and the load unit are used for adjusting the voltage of a direct-current bus and keeping the power balance, when the direct-current microgrid is switched between the working modes, the photovoltaic power generation unit, the wind power generation unit, the energy storageunit and the load unit are switched to the corresponding working modes, and plug and play of the direct-current microgrid under the off-grid condition is achieved. Compared with the prior art, the method has the advantages that the method can still work normally without communication to achieve plug and play, the dynamic characteristics of the direct-current microgrid are improved, the system robustness is improved, and the stability of the direct-current voltage is maintained.

The invention relates to a power balance controller, a virtual impedance-based bipolar MMC converter station passive control strategy and a flexible direct-current power transmission system. With thepower balance controller, the virtual impedance-based bipolar MMC converter station passive control strategy and the flexible direct-current power transmission system adopted, the mutual influence ofthe output voltages of two converters can be avoided. According to the technical schemes of the invention, the power balance controller is characterized in that the power balance controller is used for balancing the active power and reactive power exchanged between the positive and negative MMC converters and an alternating-current system and providing alternating-current voltage amplitude instruction values for the positive and negative MMC converters. The operation process of the power balance controller comprises the following steps of: acquiring active power P1 and reactive power Q1 inputted to the alternating-current system by the positive MMC converter, and active power P2 and reactive power Q2 inputted to the alternating-current system by the negative MMC converter; and calculatingthe active power average value Pave and reactive power average value Qave of the positive and negative MMC converters. The power balance controller of the invention is applicable to the technical field of power system power transmission and distribution.

The invention provides a hybrid electric vehicle optimization method for energy normalization minimization based on road grade. The method comprises the following steps of initial road information acquisition, initial parameter setting, fuel equivalent factor calculation, fuel equivalent consumption rate calculation, speed conversion factor calculation and energy normalization minimization calculation. The hybrid electric vehicle optimization method for the energy normalization minimization based on the road grade is adopted on the premise that the vehicle dynamics performance is met and the actual condition of the road is considered, the optimization of energy consumption is guaranteed, and meanwhile, the electric quantity balance of a storage battery is guaranteed, so that the performance and the service life of the storage battery are ensured. The method also overcomes a defect that a traditional energy optimization method needs to obtain a future vehicle working condition in advance, and meanwhile, the method has extremely short operation time, so that the method has extremely strong real vehicle application prospect.

The invention relates to the field of flexible direct current transmission, in particular to a power control method for a faulty process of a flexible direct current power grid system. By collecting the active power reference value of each pole of the converter station, the measured value and the operation mode of each converter, the total redundancy capacity of the receiver converter is calculated, When a fault occurs in the receiving converter, the difference between the total redundant capacity of the receiving converter and the capacity of the faulty converter is judged. If the differenceis positive, only the control mode is switched. If the difference is negative, the total power of the sending converter station of the fault pole layer is reduced to the maximum transportable capacityof the other receiving converters of the fault pole layer. At that same time, the power of each perfect pole is distributed actively, the power balance of the direct current system is ensured, and the stable operation of the system is realized. The invention can meet the requirements of the stable operation of the flexible direct current network system through the mean of active power regulation.

The invention provides a networking direct-current microgrid energy cooperative control method, which comprises the steps: different voltage level layers are divided according to a direct-current busvoltage value of the direct-current microgrid; and the voltage level layers are set to be working modes, at least one local unit in each working mode exists to control the direct-current bus voltage,and system power balance is kept. A control method is designed for each local unit in the direct-current microgrid, and different working modes are switched when the voltage of the direct-current buschanges. According to the networking type direct-current microgrid energy cooperative control method provided by the invention, the working mode can be adjusted according to the working voltage valueof the direct-current microgrid, the system power balance is maintained, and the plug-and-play requirement of each unit under a non-communication condition is met.

The invention discloses a minimum equivalent fuel consumption-based hybrid electrical vehicle control method, which comprises the following steps of: acquiring a nominal equivalence factor offline; acquiring signals; identifying working conditions; performing adaptive regulation; and performing optimum control. Under the condition of meeting the requirement of dynamic property, the minimum equivalent fuel consumption-based hybrid electrical vehicle control method is adopted, adaptive regulation can be performed according to an actual working condition, and the electric quantity balance of a storage battery is ensured, so that the performance and service life of the storage battery are ensured. The nominal equivalence factor is acquired through simulation calculation in the offline state, and calculated quantity for real-time control of the whole vehicle is reduced. In addition, different from a global optimal control method in which a future vehicle running working condition is required to be known (the future vehicle running working condition is unpredictable actually), the method has high implementability; and by the method, the real-time optimal energy management decision can be provided, the fuel economy of the whole vehicle is further improved, and the emission is reduced.

The invention discloses an optical storage power generation system control method and a storage medium, the method is applied to an optical storage power generation system based on a VF source type virtual synchronous machine working in an off-grid state, and the method comprises the following steps: obtaining photovoltaic output power and load power of the optical storage power generation system; judging whether the photovoltaic output power is greater than the load power; when the photovoltaic output power is smaller than the load power, setting a voltage component according to the direct-current voltage deviation of the optical storage power generation system; superposing the voltage component on the voltage loop, adjusting the output power of the optical storage power generation system, and enabling the output power to be matched with the load power; and when the photovoltaic output power is greater than or equal to the load power, if the charge state of the energy storage battery reaches a limit value or the energy storage system cannot work normally, the photovoltaic working mode is converted into a variable power tracking mode, and the photovoltaic output power is changed by adjusting the photovoltaic working voltage, so that the balance between the photovoltaic output power and the load power is realized. The method can effectively ensure power balance in the system and improve the stability of the system.

The invention discloses a method for managing an energy storage battery in a micro-grid. The method comprises the steps of determining a power flow direction according to output power of a distributed power supply in a micro-grid system, output power of a power distribution network and a charge state of the energy storage battery; calculating service life of the energy storage battery; and controlling electric discharge of the energy storage battery through service life management cost and electricity purchasing cost of the energy storage battery. According to the method, the service life of the energy storage battery is prolonged and the cost is reduced.

The invention discloses an AGC rapid control method adapted to a big receiving end provincial power grid, and the method comprises the steps: building an AGC control model and a rapid control relatedmodel at a dispatching center, and monitoring the disturbance condition of the power grid in real time; calling the remaining units of a plant and other units in a subregion if a unit tripping disturbance accident happens to the power grid. If a cross-region DC locking disturbance accident happens to the power grid, a pumping and storage unit in a water pumping state is automatically switched to ahalt state at first, and the remaining power shortage is adjusted by the pumping and storage, water power and common units in the subregion. When a big power reduction disturbance fault happens to the power grid, a high-rate unit which is close to the unit is called at first for power support, thereby guaranteeing the overall power balance of the power grid, giving consideration to the operationsafety of an internal section of the power grid, and avoiding the large-range transfer support of power.

The invention relates to an electric tractor wireless energy transmission power system and method. The electric tractor wireless energy transmission power system comprises an internal module and an external module, wherein the internal module is arranged inside a tractor body to achieve the functions of receiving alternate current energy generated by induction in an alternating magnetic field andpower supply of an overall power system; wireless energy transmission power receiving modules of the internal module are arranged at the front, in the middle or at the rear of the middle of the bottomof a tractor or at the front, in the middle or at the rear of the left and the right of the tractor; the external module is arranged in a tractor ground moving rail or within the energy transmissionrange of left and right vertical rails and achieves a function of energy transmission of the alternating magnetic field produced by an alternate current electric field through a high-frequency inverter; the internal module and the external module achieve wireless energy and power transmission through non-contact electricity transmission with electromagnetic induction, electromagnetic resonance andmicrowave.

The invention relates to a microgrid hybrid energy storage system and a control method thereof. The system comprises a power grid, wherein the power grid is connected with a microgrid common ac bus, the microgrid common ac bus is connected with a first subcircuit bus and a second subcircuit bus through microgrid energy management systems respectively, and the microgrid common ac bus is also connected with the first subcircuit bus through a transformer TM4; the microgrid common ac bus is also connected with the first subcircuit bus through a transformer TM5; the first subcircuit bus is connected with a lithium battery energy storage module, a super-capacitor energy storage module and a lead-acid cell energy storage module; the second subcircuit bus is connected with a load module. A microgrid internal energy storage system and loads are predicted, internal energy storage devices and loads are optimized and controlled during grid-connected operation, isolated network operation and state switching of a microgrid according to an energy storage power source and load characteristics, system output is smooth, and then intermittency and volatility of renewable energy sources are effectively inhibited.