62 results about "Grid friendly" patented technology

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.

This invention discloses a system and method to operate a doubly-fed induction generator (DFIG) as a grid-friendly virtual synchronous generator (VSG). It comprises a DFIG modeled as a virtual differential gear that links a rotor shaft driven by a prime mover, a virtual stator shaft coupled with a virtual synchronous generator G and a virtual slip shaft coupled with a virtual synchronous motor M, and a variable frequency drive that behaves as a virtual synchronous motor-generator set to regulate the speed of the virtual synchronous motor M so that the speed of the virtual stator shaft, i.e., the speed of the virtual synchronous generator G, is within a narrow band around the grid frequency even when the rotor shah: speed changes. As a result, a grid-connected DFIG can be controlled to behave like a virtual synchronous generator without using a PLL.

The invention discloses a low-voltage traversing control method for a double-fed wind power generation system. The method comprises the following steps of: 1) detecting zero frequency transient flux component of a motor; 2) when the motor has zero frequency transient flux component outburst, controlling a rotor current transformer and a network current transformer, and attenuating the zero frequency transient flux components of the current transformers; and 3) controlling torque current and power grid reactive compensation current to inhibit the growth of harmful voltage and prevent the formation of harmful current. The method can really realize the elimination of the transient flux caused by sudden decline and sudden rise of a stator voltage and inhibit negative sequence current so as to avoid offline of the fan power generation system at the same time of protecting the rotor current transformer and the network current transformer; meanwhile, by the method, double times ultrahigh dangerous voltage of rotor induction caused by zero frequency transient flux superposition when the voltage is recovered can be prevented, and power grid-friendly intelligent low-voltage traversing is realized.

The invention discloses a new-energy power generation system friendly to power grid and flexible to extend. The power generation system is composed of no less than one power generation unit, and each power generation unit is internally provided with a DC bus and the DC bus has constant voltage; photovoltaic power generation is firstly transmitted to the DC bus via a photovoltaic controller; wind power generation is firstly transmitted to the DC bus via a wind energy converter; when the power generation system is used for grid-connected power generation, an energy-storage device can be equipped, and when the power generation system is used for off-grid power supply, a battery energy storage device needs to be equipped; a frequency converter has DC input and AC output, the DC side is connected with the DC bus, and the motor is controlled to operate in a variable frequency and speed regulation mode; the motor is connected with a synchronous generator via a coupler, the synchronous generator is driven to generate power, and photovoltaic power generation and wind power generation are accessed to the power grid via the synchronous generator; the DC bus can also be connected onto a grid-connected inverter whose rated power is 10% to 30% of that of a power generator or a two-way converter; and the two-way converter can transmit power of the power grid to the DC bus, and is matched with the power grid for peak regulation and frequency modulation.

The invention discloses a household load classification power grid friendly response control method. The method is characterized by enabling frequency response state of a power grid to be stepped through monitoring frequency and frequency fluctuation change rate of the power grid in real time; classifying household load into adjustable load, interruptible load and remindable load according to the performances of household appliances; and according to the relation between power grid real-time frequency and stepped frequency value and relationship between the power grid frequency fluctuation change rate and response indexes, realizing a control strategy that various loads friendly responds to the corresponding state frequency actively. According to the method, the function that the household load friendly responds to the grid frequency initiatively is achieved, thereby not only meeting power utilization experience of users, reducing operation cost of grid companies, but also improving construction of smart power grids and realizing the purpose of energy saving and emission reduction.

The invention provides a hybrid energy storage power coordination control method in a combined light storage power generation system. The method comprises steps that, dual-layer control on the combined light storage power generation system is employed, and power distribution of a hybrid energy storage unit is realized through frequency coordination control; according to available capacity apportionment instruction power of the hybrid energy storage unit, management on expect frequency absorption or emission of each current transformer is carried out. Through the method, impact of high frequency photovoltaic fluctuation components on the electrical network is reduced, schedulability and electrical network friendliness of a distributed photovoltaic power generation system are improved, and a new method is provided for operation and control of the combined light storage power generation system.

The invention provides a power-grid-friendly air conditioner controller and a control method of the power-grid-friendly air conditioner controller. The power-grid-friendly air conditioner controller comprises an air conditioner control MCU module, a power grid parameter detection module, a temperature measurement module, a storage module, a communication module, a function display module and a power supply module. The power grid parameter detection module can detect and store real-time voltages and real-time frequencies of a power grid according to a certain cycle. The temperature measurement module can detect and store the current environmental temperature in real time. The storage module can store two kinds of working mode data. The function display module is used for displaying current power grid parameters, environmental parameters and the working state of an air conditioner. The air conditioner control MCU module is used for adjusting operating parameters of the air conditioner in real time according to changes of the voltages of the power grid and controlling the operating state of the air conditioner. On the premise of not influencing electricity utilization experience of users, an air conditioner load can participate in friendly response of the power grid, and the power-grid-friendly air conditioner controller can increase safe and stable operating capacity of the power grid.

The invention provides a high-capacity energy storage power station connected with grids by synchronous motors, and is applicable to constructing hundred megawatt level battery energy storage power stations. High-capacity and natural grid-friendly grid connection characteristics of the synchronous motors in electric power systems are used for reference. The high-capacity energy storage power station comprises one or more power station unit. The power station units comprise energy storage systems, PCS (process control systems), first motors, couplings and second motors. The high-capacity energy storage power station has the advantages that the first motors and the second motors not only can be operated as motors, but also can be operated as power generators, and motor groups can be formed by the first motors and the second motors via the couplings; the second motors are the synchronous motors and are connected into the medium-voltage and high-voltage grids; operation states of the first motors can be quickly regulated by the PCS, excitation systems of the second motors can be regulated by the second motors, active power and reactive power can be transmitted to the alternating-current grids or can be absorbed, accordingly, bidirectional flowing and four-quadrant operation can be carried out on energy, and the high-capacity energy storage power station participates in frequency modulation, peak regulation and voltage regulation of the electric power systems and can be used as a black start power source for the electric power systems.

The invention relates to a dynamic frequency division wind power generation system with autonomous inertia response. The system comprises a wind power plant, a wind power plant step-up transformer, alow-frequency alternating-current power transmission line, a power transmission step-down transformer, a winding rotor asynchronous motor, an electric excitation synchronous motor, an excitation system and a control unit thereof, a coupling unit, a double-alternating-current-port frequency converter, a frequency converter controller, a grid-connected device, switching equipment, a step-down transformer, a starting resistor, a detection unit and a central controller. Compared with the systems in the prior art, the synchronous motor in the isolated variable-frequency transformer is used as the power grid interface and the whole system shows the characteristics of the synchronous generator for the power grid and facilitates stable operation of the system. In addition, after the whole system is started, the winding rotor asynchronous motor provides centralized frequency conversion for the wind power plant under the control of the dual-port alternating-current frequency converter, the converged electric energy of the wind power plant drags the electrically excited synchronous motor to operate at the synchronous rotating speed and the characteristic of power grid friendliness is achievedunder the cooperation of the excitation system and the control unit of the excitation system.

The invention provides a method and a device for controlling the coordinated operation of a wind power and solar power complementary system. A maximum power output predication value of wind power anda maximum power output predication value of solar power are calculated at first; then wind power output dispatch instruction values and solar power output dispatch instruction values at various moments are determined through a multi-target optimization module; and then the actual power of a wind power plant and the actual power of a solar power plant in the wind power and solar power complementarysystem are controlled according to the wind power output dispatch instruction values and the solar power output dispatch instruction values at the various moments. By adopting the method and the device provided by the invention, the grid connection of renewable energy sources is promoted, the abandoned air volume is reduced, and the benefits of the grid connection are increased; the maximizing ofthe benefits of the grid connection of the wind power and solar power complementary system and the variance of the grid-connected output power are coordinated better, and the grid connection of the renewable energy sources and the friendly operation of the relative power grid are facilitated.

The invention discloses a power grid friendly wave energy power generation collecting system and an operation control method thereof. The system comprises an offshore confluence station or booster station, an electric energy storage system, a wave energy power generation centralized control system and a wave energy power generation system; electric energy of the wave energy power generation systemis collected by the offshore confluence station or booster station and then is transmitted to a receiving end power grid through a submarine cable; the electric energy storage system is connected toa grid connection access point of the wave energy power generation system in the receiving end power grid; the wave energy power generation centralized control system is arranged on the side of the receiving end power grid connected to the wave energy power generation system; the wave energy power generation centralized control system obtains the operation state and sea condition information of each wave energy power generation device, the operation state of the electric energy storage system and the state information of the receiving end power grid; and the wave energy power generation centralized control system is also used for issuing dispatching instruction targets to each wave energy power generation device and the electric energy storage system. According to the power grid friendly wave energy power generation collecting system and the operation control method thereof, the power grid friendliness of the wave energy power generation system is improved, and active participation involtage regulation and frequency modulation operation control on the receiving end power grid is realized.

The invention relates to a quantitative estimation method for friendliness of a power grid accessed to a doubly-fed wind field. On the basis of input-state stability equivalent definition form integral-integral estimation, local input-state stability/local input-output stability attribute of a sub-system is estimated in advance by a simulation method, the local input-state stability/local input-output stability attribute comprises maximum input integral energy, local stability domain, Alpha<0><IOS>/Alpha<0><ISS> and asymptotic gain, and the asymptotic gain is estimated by segmented linear form; and a small gain condition and a local stability limit of a power system after being connected with the doubly-fed wind power are calculated and acquired according to stability quantitative estimation criterion of an interconnection system, and the friendliness of the power grid accessed to the doubly-fed wind field is quantitatively estimated. The correctness of the proposed method is verifiedby time domain simulation. By the quantitative estimation method for the friendliness of the power grid accessed to the doubly-fed wind field, the influence of grid connection of the doubly-fed wind field on quantitative stability of a short-term voltage of the power system can be researched.

The invention discloses a distributed cooperative control method for load virtual synchronous machine based on consistency. The method comprises the steps of: controlling an electric vehicle by adopting a load virtual synchronous machine technology to supply a grid-friendly interface for the electric vehicle to achieve interaction with the power grid; then, constructing a distributed communicationnetwork to update the voltage and the reactive information of each node in real time based on the dynamic consistency algorithm, achieving information interaction between adjacent electric vehicle type LVSMs in a low-bandwidth communication mode to obtain a global average voltage estimation value the reactive output reference value of each electric vehicle type LVSM and achieve the purpose of reasonably distributing the reactive output of the electric vehicle type LVSMs while compensating the voltage of the power grid. The method provided by the invention achieves interaction of the electricvehicle participating in the power grid and can reasonably distribute the reactive output of the LVSMs while compensating the voltage of the power grid when the voltage drop of the power grid occurs.

The invention discloses a day-ahead optimization method for joint scheduling of an air conditioner load and an electric vehicle charging load. The method comprises the following steps: 1) establishing a building total electrical load day-ahead prediction model considering the electric vehicle charging load; 2) performing multi-objective optimization on the building total electrical load day-ahead prediction model in view of two aspects including system operation economy and power grid friendliness; and 3) establishing a comprehensive evaluation calculation method, and determining a comprehensive optimal operation scheme on the Pareto frontier. According to the invention, on the basis of the characteristic that two demand response resources of the electric vehicle charging load and the air conditioning load can both provide flexibility for power grid operation and have complementation in time, a building total electrical load day-ahead prediction model considering the two resources at the same time is established, and a day-ahead optimization method is provided for joint scheduling of an air conditioner load and an electric vehicle charging load.

The invention provides a power grid frequency disturbance process wind storage coordination control method and system. The method comprises the steps of obtaining power grid frequency data in real time, and calculating a difference value between a current power grid frequency and a power frequency, determining a current frequency disturbance mode based on the difference value, and according to different frequency disturbance modes, adopting a control strategy reserved based on a pitch angle, considering the influence of the variable pitch rate on the load characteristics of the unit, and using an energy storage device for releasing electric energy. The scheme makes full use of the advantages of convenient energy release, no time delay of power output, stable and controllable power output and the like of the energy storage device, cooperates with the primary frequency modulation control strategy of the wind turbine generator, achieves the purpose of reducing the impact load and fatigue damage of the shaft system, and has a great significance for optimizing the load design of the wind turbine generator, improving the power grid friendliness characteristic of the wind turbine generator and guaranteeing safe and stable operation of units and power grids.

The invention relates to a variable speed constant frequency control method after grid connection of a wind driven generator set, which comprises the following steps: when the wind speed changes, a wind wheel torque is changed, and the mechanical torque of a speed regulation motor shaft is also correspondingly changed; the torque current of a speed regulation motor is changed so as to change the electromagnetic torque of the speed regulation motor and make the electromagnetic torque balanced with the mechanical torque of the speed regulation motor; when the torque current of the speed regulation motor is changed to a certain extent, the corresponding electromagnetic torque is computed, and an optimum rotating speed corresponding to the electromagnetic torque is determined; the optimum rotating speed value is used as a new set value to regulate the speed of the speed regulation motor; and when a wind wheel achieves a rated rotating speed, the speed regulation motor stops working. According to the invention, only the speed regulation reference of variable speed constant frequency control is changed from the rotation speed of a power generator into the torque of the speed regulation motor, the variable speed constant frequency operation requirement of the power grid friendly type wind driven generator set is met, the reliable operation of the wind driven generator set is realized, and grid-connected operation stability is improved, so the method is suitable for being used and popularized.

The invention relates to a quick charging technology for a new energy automobile, and particularly relates to a quick charging system used for a power grid friendly type new energy automobile and charging method of the quick charging system. The charging system comprises a power grid and a vehicle-mounted accumulator; the charging system further comprises a voltage transformation rectification filtration module, a super-capacitor bank charger module, a buck chopping module and charge control modules; the power grid is successively connected with the voltage transformation rectification filtration module, the super-capacitor bank charger module, the buck chopping module and the vehicle-mounted accumulator, and the charge control modules are connected with the super-capacitor bank charger module and the buck chopping module; the charge control modules are used for conducting real time monitoring on voltages and electric quantities of the super-capacitor bank charger module and the vehicle-mounted accumulator, and giving the feedback of the voltages and electric quantities to the super-capacitor bank charger module and the buck chopping module. The quick charging system supports the fast charging of the new energy automobile, and does not have impacting loads on the power grid, can adjust electricity consumption during peak and valley period, optimize electric power distribution and load balancing and can help a user save cost in battery charging; besides, circuit topology is very simple, and thus the quick charging technology can be put to a wide range of popularization and application.

The invention discloses an evaluation index system for good interaction between electric energy conversion equipment and an intelligent power distribution net friend. The invention relates to the fields of power generation, power transmission, power transformation, power distribution and power utilization. The system comprises a target layer, a criterion layer, a sub-criterion layer and a measurelayer, classifying each index hierarchical structure; the target layer comprises an overall target of good interaction between the electric energy conversion equipment and the intelligent power distribution network friend; the criterion layer indexes comprise three indexes which are safe, high-quality and intelligent and relate to friendly interaction targets; wherein the indexes of the sub-criterion layer comprise nine indexes related to the operation capability, such as the stable operation capability, the output optimization capability and the energy routing capability, and the indexes of the measure layer comprise 36 indexes related to the specific interaction performance, such as the working voltage allowable range, the operation efficiency and the distributed energy permeability. According to the invention, multiple dimensions can be provided to analyze and describe the friendliness of the interaction between the electric energy conversion equipment and the intelligent power distribution network, so that the friendly interaction evaluation is changed from qualitative to quantitative.

The invention relates to a wind-solar-storage multi-energy complementary capacity optimization method considering installation scale constraint. The method comprises the following steps: acquiring wind resource and solar resource data of a place where a project is located, output data of wind power and photovoltaic power generation under unit installed capacity at each moment in a year, historical load data and a daily minimum load rate value in the whole year; a wind-solar optimization complementary system; the wind-solar optimization and complementation system takes the total wind-solar installation scale as a constraint condition, wind power and photovoltaic power generation installation scales as variables, and smooth new energy joint output through wind-solar complementation characteristics as an optimization target, constructs a wind-solar complementation optimization model, and calculates the optimal wind power and photovoltaic power generation installation scale under wind-solar complementation; an energy storage capacity configuration system; and optimizing the energy storage capacity configuration scale and the configuration duration according to the energy storage capacity demand of each time period of the annual daily load valley period and the energy storage capacity demand of each day. According to the method, the wind power and photovoltaic power generation total installation constraint, the wind-solar complementary characteristic, the new energy development economy and the power grid friendliness can be comprehensively considered.