3483 results about "Micro grid" patented technology

The Electric Power Converter has the qualifications for an uninterruptable power supply, battery management, energy conversion, micro-grid formation, Power Factor Correction including Total Harmonic Distortion correction in real time. Uninterruptable power supply's use is for always-on, real-time, all-time, reduced distortion with functions of load reduction and management during peak load events. The Electric Power Converter as well has the ability to provide maintenance for most types of batteries including charging and discharge regiments to increase the overall lifetime of a battery, the maintenance, incorporating restorative functions that can refurbish dead batteries or can further increase the overall efficiency and useful function of weaker/aged/defective batteries. Energy conversion capabilities allow for the conversion of AC or DC to AC or DC with high efficiency and ability to actively vary the frequency in accordance to the required parameters. The Electric Power Converter is able to establish and sustain a micro-grid with multiple and varying sources of power generation and load conditions. The Electric Power Converter is achieving dynamic, real-time, interactive Power Factor Correction (PFC) function with advanced voltage harmonic distortion correction with a high efficiency ratio. The Electric Power converter is designed to function with the emerging Smart Grid technologies and provide an overall higher level of operating efficiency and higher quality of electrical power.

The invention relates to the technical field of photovoltaic micro-grid control, and particularly discloses a real-time coordination and control method of a photovoltaic micro-grid system. A central real-time optimal control layer and a local control layer are involved in the real-time coordination and control method. The central real-time optimal control layer collects the voltage and frequency of an AC bus of the photovoltaic micro-grid system, the charge state of a storage battery pack, the output power of photovoltaic power generation micro-sources, the output power of the storage battery pack, the output power of a super capacitor and the real-time power of a load in real time, generates a real-time coordination and control strategy and a secondary frequency modulation and scheduling plan, and issues the strategy and the plan to all local controllers. The local control layer coordinates and controls all the micro-sources in real time, and particularly achieves the scheduling plan issued by the central real-time optimal control layer. According to the real-time coordination and control method, a micro-grid central optimizing controller can manage, coordinate and control all the local controllers in a unified mode, the micro-grid can efficiently and economically run, the output power of the photovoltaic power generation unit is utilized to the maximum extent, the output power fluctuation and the tracking load change of the photovoltaic power generation unit are restrained, the running method of the micro-grid is reasonably adjusted, and energy balance is achieved.

The invention discloses an optimal virtual inertia control method based on a virtual synchronous generator in the distributed power generation control field. According to the method, a control strategy of a virtual synchronous generator is employed for a micro-grid inverter to organically combine three control degrees of freedom including a droop coefficient m, a virtual inertia J and a virtual damping D, and thus optimization of key parameters of the virtual synchronous generator is achieved. Through adoption of the method, the inertia advantage of a conventional synchronous generator is fully exhibited, and the stability and the inherent dynamic performance of an inverter are also taken into consideration. Moreover, the output power and frequency oscillation problems brought by virtual inertia are solved while the power and the capacity configuration of an energy storage apparatus are considered.

The invention discloses a micro-grid planning and capacity allocation method based on multi-objective optimization. The method is characterized in that the method comprises the steps of (1) setting the operation mode of a micro-grid, wherein the operation mode of the micro-grid comprises an independent mode and a grid-connected mode; (2) inputting basic data which comprise the system condition, electrovalence parameters, load parameters, photovoltaic parameters, wind electricity parameters and storage battery parameters; (3) pre-processing the basic data; (4) optimizing a distributed power supply and an energy storage system. According to the micro-grid planning and capacity allocation method, distributed power supply capacity and energy storage system capacity in micro-grid planning can be solved jointly, and optimizing allocation can be carried out at the same time.

The invention discloses a micro-grid multi-objective optimized operation control method, which comprises the steps of: constructing a micro-grid operation indicator function aiming at wind-light complementary and cold, heat and electricity combined supply micro-grid; then constructing a complete small signal model of the micro-grid for theoretical analysis to provide theoretical guidance for the multi-objective optimized operation control of the micro-grid; and finally on the basis of a multi-objective intelligent optimization theory, comprehensively using power system computer aided design (PSCAD)/electromagnetic transients including direct current (EMTDC) and MATLAB software to design the micro-grid multi-objective optimized operation control method, so as to enable the micro-grid to realize comprehensive optimization of multiple operation indicators such as economy, cleanness, reliability, stability, dynamic performance and the like in different operation modes such as a synchronized operation mode, a mode capable of being switched between the synchronized operation mode and an independent operation mode, an independent operation mode with sudden load change and a resynchronized operation mode.

The invention discloses a planning method and system for optimizing a micro-grid containing distributed power sources and stored energy, wherein the planning method and system are based on an intelligent optimization algorithm. The planning method is used for optimizing the micro-grid containing the distributed power sources and the stored energy, and comprises the steps that basic data are provided for a planning and design scheme, and modeling and load flow calculation are performed on an area to be planned; a micro-grid wiring mode suitable for the area to be planned is determined; site locations, to be chosen, of the multi-type distributed power sources are determined; a site distribution and capacity determining model is established, and a grid frame of the micro-grid containing the distributed power sources and the stored energy is planned and designed; a joint planning scheme and a joint planning module under a decided investment subject are formed; the joint planning scheme is output and evaluated. According to the planning method and system for optimizing the micro-grid containing the distributed power sources and the stored energy, on the basis of basic characteristic study of the distributed power sources and the micro-grid, planning for optimizing the micro-grid containing the photovoltaic power sources is systematically studied, the positions, capacities and the grid frame structures of all kinds of distributed power sources in the micro-grid in the specified planning area are reasonably allocated, and the micro-grid optimization planning scheme which is complete, effective and high in integrity, and is closely integrated with engineering practice is established.

Disclosed is a comprehensive coordination control method of a wind-solar direct current micro-grid. The wind-solar direct current micro-grid comprises wind driven generator and alternating current (AC)/direct current (DC)/DC converters, photovoltaic array and DC/DC converters, a circuit interrupter, AC/DC load and DC/AC and DC/DC converters, a DC bus, a supercapacitor energy storage system and bi-directional DC/DC module, a storage battery energy storage system and bi-directional DC/DC module, a bi-directional AC/DC converter, a coordination controller, a control network for connecting the coordination controller and the converters and a communication network for connecting the coordination controller and a large power grid power scheduling center, and an operational mode of the wind-solar direct current micro-grid is divided into two categories of a grid-connected mode and an island mode. Stable operation of the wind-solar direct current micro-grid under the grid-connected mode and the island mode is achieved by comprehensively using power scheduling, load scheduling and energy storage device scheduling.

The invention discloses a dynamic power coordination control method for a battery energy storage system. The battery energy storage system comprises a plurality of power converters which supply power to a load and are connected in parallel for operation, and is characterized in that: the power converters connected in parallel for operation are divided into two types, and a master-slave control scheme is adopted, wherein one type comprises only one power converter which adopts a constant voltage constant frequency control mode and is called a master node, and the power converters of the other type adopt a constant power mode with a slight droop characteristic, and serve as slave nodes; generally, a power converter with a high capacity is selected to be the only one master node which is specified by an upper-layer monitoring system, and all the other power converters are the slave nodes; and under a stable state condition, active power and reactive power output by the power converters which serve as the slave nodes are set by a power instruction transmitted by the monitoring system, and the output power of the power converter which serves as the master node is dynamically regulated according to a load condition. The method adopting the master-slave control scheme has the advantages that: on the premise of sufficient power capacity, both the voltage stability and frequency stability of a micro-grid system are easily achieved, anti-load disturbance capability is high, and failure recovery time is short.

The invention discloses an alternating current and direct current hybrid micro-grid system and a control strategy of the micro-grid system. The micro-grid system comprises multiple generation units, load, a distribution line for connecting the generation units and the loads, and a monitoring protection unit; each generation unit comprises a large power grid, grid-connected AC/DC (alternating current/direct current) of the large power grid, an energy storage system, a DC/DC (direct current/direct current) converter of the energy storage system, a wind power generation system, an AC/DC converter of the wind power generation system, a photovoltaic power generation system, a DC/DC converter of the photovoltaic power generation system, and a diesel generator; said load includes AC non-significant load, AC significant load, AC/DC load, DC significant load and DC non-significant load; the distribution line comprises a DC distribution line and an AC distribution line; the operating status of each energy conversion device can be monitored in real time by the monitoring protection unit, two operating ways such as grid connection and isolation of the system can be realized by different control strategies, the distributive generation unit and the energy storage unit realize coordination and cooperation by controlling energy storage DC/DC, photovoltaic DC/DC, and wind power AC/DC, so that the power supply reliability is improved and the significant load can continuously operate.

The invention relates to a smart micro-grid system. The smart micro-grid system comprises a local control layer, a network communication layer, a master station layer and a software layer, wherein the local control layer is in communication with the master station layer through the network communication layer, and the master station layer is in communication with the software layer through an information interaction bus. The smart micro-grid system integrates photovoltaic power generation, wind power generation, multiple types of energy storage systems multiple in capacity and modern power electronic, communication and control technologies. While high-reliability power supply is achieved, optimized allocation of renewable energy resources and high-reliability power supply to loads in a micro-grid are achieved; the interaction relation between the micro-grid and an external power grid is reflected correctly, and the effect of distributed energy on improvement of power supply reliability is fully shown; operation data of photovoltaic, wind power and energy storage systems and the micro-grid systems can be collected and stored, and the operation data are accumulated for researches on key technologies about micro-grids. The smart micro-grid system solves the problems that an existing micro-grid system is low in energy utilization ratio and poor in environmental benefit, electric energy quality and power supply reliability.

The invention provides a control method of a grid friendly type distributed power source based on hybrid energy storage. The method comprises the steps of optimally designing a topology structure of the distributed power source, controlling a direct current power supply system in a coordinating mode through a direct current (DC)/DC converter controlling a model normalization model, and self-adaptively controlling a grid of an alternating current (AC) side DC /AC converter. The distributed power source not only can be connected in a large grid to operate so as to reduce the influence of intermittent renewable energy power generation grid connection on the grid and provide support of voltage and frequency for the grid, but also can be connected into a micro-grid to operate as a network unit of the off-network type micro-grid to maintain stability of voltage and frequency of the off-network type micro-grid. When an outer grid breaks down, the distributed power source can realize switch between a grid mode and an island mode so as to improve power supply reliability of important loads in the system. The distributed power source improves technical performance and economic performance of the whole system through matching utilization of an energy type system and a power type energy storage system.

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 microgrid power source planning method based on game and Nash equilibrium. Cooperative game optimal configuration models are established with identities of different participants respectively, generated output characteristics of micro sources of different kinds in a microgrid and various constraint conditions are taken into full consideration, a game is carried out between revenue functions formed by microgrid electricity sell revenue, investment cost of the microgrid, system losses cost, environment cost and interactive power cost and revenue functions formed by loss reduction revenue of large power grid loss, electricity sell revenue to the microgrid, discharged exhaust gas cost due to electricity sell to the microgrid and hot standby cost saved by a large power grid, solving is carried out by adopting a game iterative algorithm, and the power source planning problem of the game models is solved. Simulated analytical investigation is carried out by adopting a typical microgrid structure, simulation results show that cooperative the game between the microgrid and the large power grid can achieve better revenue, and therefore sound development of the microgrid can be promoted by combining power of all interested parties.

The invention discloses a micro-grid system voltage stability control method based on robust control. The control structure of an intelligent micro-grid system is composed of a system control layer, a concentrated control layer and a local control layer, and energy optimization and voltage and frequency stability control of the micro-grid system are realized through multi-layer coordination control. According to the micro-grid system voltage stability control method based on robust control, a comprehensive load module of an induction motor is established, wherein dynamic loads are connected with static loads in parallel. On the premise that the constraint conditions of system performance and robust stability are met, a micro-grid voltage stability robust controller is designed by the adoption of a method of solving the problem of mixed sensitivity so as to improve the micro-grid voltage stability. The micro-grid system voltage stability control method based on robust control can be adapted to wide-range change of load parameters, has high robustness for the situations that due to the factors such as changes of running conditions, influences of external environment and frequency switching of the loads, perturbation is generated in model parameters of a micro-grid and uncertainty exists in the topologic part and the unmolded part and can better restrain parameter drift and noise interference, and meanwhile, the controller is simple in structure and easy to realize.

A transmission electron microscope (TEM) micro-grid includes a metallic grid and a carbon nanotube film structure covered thereon. A method for making a TEM micro-grid includes the steps of: (a) providing an array of carbon nanotubes, quite suitably, providing a super-aligned array of carbon nanotubes; (b) drawing a carbon nanotube film from the array of carbon nanotubes; (c) covering the carbon nanotube film on a metallic grid, and treating the carbon nanotube film and the metallic grid with an organic solvent.

The invention discloses a micro-grid capacity programming method meeting a coupling type electric cold and heat demand, comprising: establishing a micro-grid capacity energy supply device capacity programming model meeting a coupling type electric cold and heat demand, and a micro-grid capacity energy supply device optimum capacity programming calculation method based on the multi-target particle swarm technology. According to the mode, the method solves the problem that a current programmed micro-grid needs to simultaneously provide power supply and cool supply (or heat supply) for users, and the problem of capacity optimum allocation among different energy supply devices when a coupling relation exists between electric cold supply and electric heat supply. The model realizes multi-target optimization under the condition of considering engineering, economy and security constraints of micro-grid energy supply devices.

The invention provides a micro-grid new energy hybrid energy storage system which comprises a new energy power generation subsystem, an energy storage carrier subsystem, a converter subsystem, a high/low-voltage power distribution subsystem and a background monitor subsystem. According to the invention, battery equalization is performed through a BMS (battery management system), a cask effect caused by non-uniformity of voltage, capacity and other parameters is avoided, and the phenomena that the capacity of the whole group is reduced and the service life of the battery is shortened due to vicious circle of performance of the battery pack are avoided. Meanwhile, a refrigeration mode of air-conditioning equipment is scientifically controlled through a heat management system, so that the battery keeps a proper, uniform and stable environment temperature in the operating process. Therefore, the service life of the storage battery is prolonged, and the operating cost is effectively reduced. A container modular energy storage scheme is adopted, the system can be designed into a miniature temporary power generation system, and the construction investment is low. The system is convenient to use and can be transported into bad condition environments such as fields for performing power generation and supply under emergency circumstances. The system can be constructed into a large energy storage power station in a centralized mode, and the capacity is conveniently expanded.

The invention discloses a hybrid energy-storage DC micro grid hierarchical control method. The DC micro grid comprises a photovoltaic power generation unit, a hybrid energy storage unit, a load unit, a networking interface unit and a DC bus, wherein each unit is connected with the DC bus respectively. By adopting the hierarchical control method, a system control layer and a current converter control layer are used for controlling the DC micro grid, the system control layer acquires networking operation mode parameters, DC bus voltage and a battery charge state to judge the current operation mode of the DC micro grid, a control mode of each unit of the DC micro grid is given, and a control instruction is sent to the current converter control layer. Each current converter can adjust the self control mode according to a different DC micro grid operation state, network voltage stability and power balance can be maintained effectively, and relative to master-slave control, excessive dependence on the master current converter is reduced; relative to a multi-agent control mode, communication is simpler; and relative to a voltage sag control mode, the network voltage is more stable and controllable.

The invention discloses a comprehensive energy system economic optimization scheduling method based on a micro-grid. The method comprises the steps that independent modeling is performed according toenergy production equipment, energy conversion equipment and energy storage equipment in a factory, and an energy supply structure for a comprehensive energy system based on an energy exchange networkis set up; considering a serial working mode and a parallel working mode of an ice storage air-conditioning system, a comprehensive energy system economic optimization scheduling model is further improved, so that the optimization model better meets the practical demand of a project; and optimization scheduling is performed on the micro-grid considering cold and hot electric balance constraint, equipment operation constraint and energy storage equipment constraint with minimum annual operation cost composed of operation and maintenance cost, electricity purchasing cost, fuel cost and stored energy depreciation cost being an optimization objective, and automatic optimization of the factory is realized. The method has the advantages that energy using efficiency at the user side is improved,energy using cost of a user is reduced, economic benefit and the energy utilization rate are increased, and the method is suitable for different types of industrial park comprehensive energy systems.

The invention provides a direct current micro-grid coordination control method of a light storage electric car charging station, and relates to the micro-grid technology field. The technical problem is solved that a direct current bus voltage is kept smooth and stable. The method employs a storage battery and flywheels for hybrid energy storage, a direct voltage is divided into five levels from high to low, layered coordination optimization control of a direct current bus is carried out, and coordination optimization control of photovoltaic power generation, electric car charging and discharging, load power requirements and grid side converter charging and discharging in a charging station direct current micro-grid is carried out. The method can keep balance of the system power in different operation modes of charging station micro-grid island and grid connection and achieves stable control of a direct current bus voltage.