106results about How to "Smooth power fluctuations" patented technology

The invention belongs to the field of distributed micro-grid deployment and management, and provides a method and system for controlling distributed micro-grid parallel operation. The method is characterized in that through monitoring environment parameters such as illumination intensity, wind speed and the like as well as real-time data such as input power, storage battery end voltage and the like and by virtue of predicted data of electricity generation power and electricity utilization load, coordination control is carried out on the output total power of a photovoltaic generating system and a fan, load, a storage battery energy storage system so as to meet a requirement of system power balance; meanwhile, a load prediction curve of 24 hours are divided into a load valley, a load flat value, a load peak and a load top value according to different power consumption in different time periods; and a discharging policy of an energy storage system is arranged according to different time periods, a charging pile can set different charging prices according to different time periods, and electric equipment utilized by a user is subjected to effective control, thereby achieving the purpose of stabilizing the electric network power fluctuation, reducing the power equipment investment and achieving an optimal economic effect and a energy-saving effect.

The invention provides a composite energy storage system, which consists of a supercapacitor and a storage battery, wherein the composite energy storage formed by the supercapacitor and the storage battery has both power type and energy type characteristics; through the combined use, the charging and discharging times of the storage battery can be effectively reduced; in addition, the utilization rate of the energy storage system can be improved. According to an energy management and control optimization method matched with the composite energy storage, the total power of the composite energy storage is distributed through a low-pass filter, so that the supercapacitor and the storage battery respectively share a high-frequency component and a low-frequency component in the fluctuating power; through the two-way DC/DC1 converter constant-power control on the storage battery, the two-way DC/DC2 converter constant bus voltage control on the supercapacitor, and control strategies of the two-way DC/AC converter, the network loss of a power distribution network is reduced; the utilization efficiency of new energy sources is improved; the power fluctuation during micro power grid interconnection is effectively inhibited; the electric energy quality of a region electric network is improved; in an offline state, the stability of the voltage and the frequency of a micro power grid system can be ensured; the power balance generated during grid connection/off-grid switching is fast compensated.

The invention discloses a railway photovoltaic energy storing system and control method for regenerative braking energy recovery. Real-time online detection and processing are carried out on all kindsof running data of a photovoltaic side, traction side and energy storing side, a comprehensive judgement is carried out on running conditions based on a calculation result, control schemes under multiple scenes are selected through a judging result, an energy storing unit is taken as an energy transferring station, the coordinated control of a back-to-back converter, photovoltaic power generationunit and energy storing unit is achieved, and the electric energy elective exchange under the multiple scenes is completed. The system and method are conductive for photovoltaic power energy nearby consumption and railway system green development, can effectively recover the regenerative braking energy of haulage motors and the photovoltaic power energy which cannot be consumed, increases systemeconomic benefits, stabilizes photovoltaic side output and power energy fluctuation of the traction side under the regenerative braking conditions, and compensates for negative sequence functions of atraction power supply system.

The invention relates to a method and system for smoothing the energy storage wind and photovoltaic power fluctuation based on rate control, including: reading and processing data; determining the signal change rate of the dynamic slope limiter; calculating the smoothing target value of the wind and photovoltaic total power; calculating total power demand of battery energy storage power station; and outputting data. The invention can effectively suppress wind and photovoltaic power fluctuation under the fluctuation rate limited value, can effectively smooth wind and photovoltaic power output. Thus it smoothens wind and photovoltaic power output, reduces the energy storage battery burden, and effectively controls battery energy storage power station system.

The invention relates to a double-fed wind driven generator system and a low-voltage through control method. According to the double-fed wind driven generator and the low-voltage through control method on the basis of a Crowbar circuit and a battery energy storage device, the low-voltage through capability can be effectively improved under the condition of large-range voltage drop, the double-fed wind driven generator system can be still kept to be connected with a power grid, and the stability of a wind power system is improved.

The invention relates to the technical field of a micro-grid, in particular to a hierarchical distributed micro-grid energy-storage battery configuration method which includes the step that lower-layer low-voltage bus storage battery configuration is carried out, wherein configuration is carried out according to functions of a storage battery in the micro-grid, and capacity configuration includes low-and-medium-frequency power fluctuation stabilization, peak load shifting and supply of voltage support for micro-grid system isolated island operation; lower-layer low-voltage bus super capacitor configuration is carried out, wherein according to functions of a super capacitor in the micro-grid, capacity configuration mainly includes local high-frequency load fluctuation stabilization; upper-layer high-voltage bus storage battery configuration is carried out, wherein according to the functions of the storage battery in the micro-grid, capacity configuration includes bus power fluctuation stabilization, system isolation island operation is maintained, and power factor compensation is provided for the whole micro-grid on a PCC point. By means of a precise configuration computing method, the power factor of grid-connected operation in the micro-grid is unique, power fluctuation of the micro-grid and a large grid is effectively stabilized on the condition that clean energy is fully used, and stability of voltage frequency of a system and continuous operation of important loads are effectively achieved.

The invention discloses a virtual energy storage contained building micro grid multi-time scale optimizing and scheduling method, comprising: modeling a building virtual energy storage system; constructing a building micro grid layered energy management framework; proposing a multi-time scale optimizing and scheduling algorithm and applying the algorithm to the building micro grid optimizing and scheduling model; calling the CPLEX under the MATLAB software environment for solutions to the optimizing and scheduling and obtaining the operation results of the virtual energy contained building micro grid before and in the middle of the current day so as to achieve the optimal operations. According to the invention, the virtual energy storage contained building micro grid multi-time scale optimizing and scheduling method is capable of reducing the operation costs of the building micro grid in the present scheduling stage under the condition that the temperature comfort is ensured; and with the method, the power fluctuation of the micro grid connection lines caused by the prediction errors before the current day can be suppressed in the correction stage in the middle of the day.

The invention discloses a multi-component composite energy storage system grid combination control method based on power prediction, comprising steps of calculating difference value PV-L of the photovoltaic output power prediction value PV and the load power prediction value PL according to the photovoltaic output power prediction value PV and the load power prediction value PL and, utilizing a wavelet packet composition method to map PV-L to the subspaces of m wavelet packets to obtain signals with different frequencies, using the frequency signals which are close to the responding frequency of a storage battery in the frequency signals as low frequency signals P low which are complimented by the storage battery and using the rest of the frequency signals and the frequency signals which are not absorbed by the battery as high frequency signals P high which are complimented by a super capacitor, using an external loop control method and an inner loop current control method to output the real power of the storage battery and the super capacitor and control the charging and discharging power of the storage battery and the super capacitor by utilizing the state of charges of the super capacitor and the current, the state of charge and maximum charge-discharge power of the storage battery according to the real condition. The advantages of the invention are safe, stable, and economic in operation. Furthermore, the times of charging and discharging of the storage battery are reduced.

The invention relates to an energy storage system based on rail transport. The energy storage system comprises high and low load fields for load parking, a transport track for load transportation, a power transmission line for providing traction power and transmission brake power generation, a traction/brake unit, a load unit, a storage track, a safety track, a control center and a power grid access module. In the invention, by means of combination of energy storage based on electrified track transport and brake power generation, in the case of excess electricity of the system, an electric traction locomotive carries heavy load from a low place to a high place so as to convert electric energy into potential energy for storage; and in the case of high demand of the electricity of the system, brake power generation is performed during the process that the electric locomotive carries the heavy load from the high place to the low place so as to convert the potential energy into the electric energy and transfer the electric energy to a power grid. The energy storage system has the advantages that energy with super-large and controllable volume and high density can be stored, the operation management method is simple, and the energy cycle efficiency is ultrahigh.

The invention discloses an intelligent building adjustable resource coordination optimal control method. By establishing an intelligent building adjustable resource optimal operation control model, coordination optimal operation of adjustable resources in an intelligent building is achieved. Grid connection of a wind turbine system is achieved through an electric vehicle and an intelligent power distribution system, and power is exclusively supplied to a controllable load of the intelligent building through the electric vehicle. Grid connection of a photovoltaic power generation system is achieved through the intelligent power distribution system, and the controllable load is supplied with power through the electric vehicle. Orderly power utility is realized for the controllable load of the intelligent building through the intelligent building adjustable resource optimal operation control model. Multi-target optimal coordination operation control over adjustable resources including the photovoltaic power generation system, the wind turbine system, the electric vehicle and the controllable load is realized by means of the intelligent building adjustable resource optimal operation control model, intelligent building tie line powder fluctuation is effectively smoothened, and overall power utilization cost of the building is reduced.

The invention relates to a distribution network flexible load cooperative dispatching method based on a particle swarm algorithm, belonging to the technical field of grid operation and control. The method comprises the following steps of: (1) considering stabilizing new energy access, peak clipping and valley filling and safe and economical operation of distribution network, establishing an optimization objective of flexible load cooperative dispatching model of distribution network; 2, synthetically considering the system balance constraint, the network constraint, the distribution power source and the adjustable load constraint, wherein each constraint condition can flexibly carry out parameter configuration and effective setting, and establishing the constraint of the optimization objective in the step 1; and 3, finally, solving the optimization objective of the load cooperative dispatch model satisfying the constraint condition by using the particle swarm optimization algorithm. This kind of cooperative control method provides space for alleviating the peak load regulation and realizing the large-scale consumption of new energy, and its economic benefits are enormous.

The invention discloses an offshore doubly-fed wind-driven generator set high-voltage ride-through (HVRT) control method and system based on supercapacitor energy storage technology. The offshore doubly-fed wind-driven generator set HVRT control method includes the steps of: obtaining a grid-connected point voltage per-unit value and the duration of a grid-connected point voltage rise; determiningwhether to activate a HVRT control mode to reduce the grid-connected point voltage; after the HVRT control mode is activated, determining whether the output active current value of a grid-side converter exceeds the active current maximum value borne by the normally operating grid-side converter; if so, determining whether a DC link voltage exceeds a critical value of the DC link voltage; and if so, starting a supercapacitor energy storage module. The method aims to avoid an off-grid accident of the offshore doubly-fed wind-driven generator set possibly caused by the sudden rise of the grid voltage in the prior art.

The invention discloses a control method based on a hybrid energy storage voltage source inverter (VSI) stabilizing microgrid power fluctuation. A hybrid energy storage system two-stage energy management method is designed. The method exploits the advantages, to the full, that according to a super capacitor, the power density is high, and charge and discharge cycle life is long; the super capacitor serves as system first stage energy storage stabilizing the microgrid power fluctuation preferentially; a distribution grid serves as second stage energy storage during grid connected operation; the super capacitor terminal voltage is stabilized in the range of a charging and discharging limited value by controlling the tie line power, and the PCC point bus voltage changes in an allowed range; a battery serves as second stage energy storage during island operation, the charging and discharging number of the battery is decreased through the buffering effect of the super capacitor, and the service life of the battery is prolonged; when the super capacitor reaches a charging and discharging warning value, the battery is accurately controlled to output constant power so as to adjust the super capacitor terminal voltage into a normal value. The effectiveness of the method is verified through simulation results.

The invention relates to a model prediction control method of stabilizing wind power fluctuation with hybrid energy storage, and belongs to the technical field of new energy power generation control. The method comprises the steps of determining a topological structure of a control object, namely a system structure comprising wind power, battery energy storage and supercapacitor energy storage, predicting an output value of the wind power within a control prediction interval by utilizing an average value method, determining an objective function and three constraint conditions of optimization control, solving an optimization problem at each moment, only obtaining optimization control quantity at the current moment, inputting the optimization control quantity into a battery and a supercapacitor for control respectively, summing power output by the battery and the supercapacitor and actual output power of the wind power, and then obtaining grid-connected power of an overall system after power fluctuation stabilization. The control method can achieve the power fluctuation stabilization of the wind power more economically and reliably, is simple in calculation, and facilitates engineering realization.

A method and system for coordinate dispatch of distribution network containing energy storage are provided, In the day-ahead dispatching stage, according to the day-ahead forecasted power data, probability distribution and load forecasting data of renewable energy, the output plan of diesel generator and the day-ahead dispatching plan of exchanged power of distribution network are determined and executed in order to minimize the daily operating cost of distribution network. In the intra-day dispatching stage, the output plan of the energy storage device is determined according to the predictedpower data of the renewable energy period and the day-ahead dispatching plan, aiming at minimizing the deviation of the exchanged power in the distribution network. The output plan of the energy storage device is executed cyclically until the dispatch is completed. The method and the system can reduce the operation cost of the distribution network by energy storage participating in the day-aheaddispatching, and can stabilize the power fluctuation between the distribution network and the large power network caused by the renewable energy prediction error, improve the controllability of the distribution network, and reduce the impact on the large power network.

The invention relates to a wind-solar complementary generation system. By a bran-new design framework, a photovoltaic power generation link is embedded into a wind power generation link, so that system output power fluctuation can be stabilized; a load in a microgrid can be adjusted; and the work efficiency of the generation system is effectively improved. The invention further relates to a control method for the wind-solar complementary generation system. The method comprises a combined control method for stabilizing power fluctuation and adjusting the load in the microgrid. By combination of a power prediction technology and a low-pass filter principle, the system generation power in the next 24 hours is predicted in advance by the perspectiveness of the prediction technology. Due to the uncertainty and the volatility of wind and solar radiation, a lot of high-frequency components exist in the actual generation power of the wind-solar complementary generation system. A predicted value is very close to an actual value, the high-frequency component in the predicted value is filtered out through a low-pass filter; and the processed predicted value is taken as a reference value of the system output power, so that the system generation power fluctuation can be effectively stabilized.

Utility (or other grid participant's) customers' intermittent power generation systems and loads (including optional energy storage) are made autonomously real time adaptive at the customer circuit level, so each of the customers' circuits (after powering that customer's varying load) contributes, at that customer's common connection to the utility meter, to the utility's (or other grid participant's) desired outcome for that customer's circuit, or contributes, at the intermediate circuit level, to the utility's desired aggregate outcomes for customers on that intermediate circuit. Energy management controllers are connected, behind the customer's utility meter on the customer's circuit, to controlled load portions of that customer's varying load, to autonomously add or shed, in real time, those controlled load portions, or (if there is stored energy) to autonomously discharge, in real time, stored power from storage. Utility (or other grid participant) rules for achieving desired outcomes can be downloaded to the controllers and customers can individually opt-in to some, all, or none, of those utility (or other grid participant) rules. Real time means within sub second to fifteen second intervals.

The invention discloses a power fluctuation smoothening method based on optimum control of energy storage and virtual energy storage. The method comprises: ascheduling reference value of a day tie-line power is obtained according to power prediction values consumed by new-energy power generation, an uncontrollable load, and controllable equipment on the uncontrolled condition; a power of the ew-energy power generation at the day t time is obtained, and a total power, needed to be smoothened, of an energy storage battery and an electric heating pump at the time is calculated; according to a state equation in an optimum control model, optimization distribution is carried out on the total power under constraint conditions and objective functions of the energy storage battery and the electric heating pump in the optimum control model, thereby obtaining objective functions of the energy storage battery and the electric heating pump; and actual response powers of the energy storage battery and the electric heating pump are calculated. According to the invention, cluster demand response controlling is carries out on lots of electric heating pumps in a micro grid of the urban park and a load curve is adjusted to form a virtual energy storage effect; and with coordination and control with the energy storage battery, the power fluctuation of the tie-line of the micro grid is smoothened.

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 a control method for stabilizing wind and photovoltaic power fluctuation with hydropower and storage energy, and belongs to the technical field of new energy power generation control. According to the method, a distributed power generation system to be controlled comprises a wind power subsystem, a hydropower subsystem, a photovoltaic power generation subsystem and a storage energy subsystem. The method includes inputting power instruction values, wind power output and photovoltaic output of a grid as required into a collecting system; then, sequentially performing power distribution, amplitude limiting cooperation and power correction on the collected information to obtain output instructions of hydropower and storage energy; finally, summing the obtained actual output power of hydropower and storage energy and the output power of the wind power and photovoltaic power generation to obtain the power input to the major grid by the entire power generation system. The control method can stabilize the power fluctuation of new energy power sources with low-cost hydropower and storage energy as well as can maintain safe and stable operations of the system.

The invention provides a network system comprising energy storage and an energy router and an energy adjustment method, and belongs to the field of application design of a renewable energy source energy control device and application of a grid-connected technology in a renewable energy source power network. The network system comprises a renewable energy source AC generation system, an AC load, the energy router, a two-way AC/DC converter and a hybrid energy storage system, wherein the overall network system can quickly and accurately carry out power throughput and energy exchange with renewable energy source power generation, achieves stabilization of short-time rapid power fluctuation of renewable energy source power generation and long-time energy supplement and storage and simultaneously meets the requirements of high power density, high energy density, long cycle lifetime and low price level. The energy router can achieve independent and accurate control and adjustment on charging and discharging of different energy storage elements according to the requirements, so that the performance advantages of the energy storage elements are fully developed in the process of achieving real-time stabilization of power fluctuation of a distributed energy source power generation system.

The invention discloses a storage battery control system smoothing power fluctuation based on wind power prediction. The system comprises a data collector, a wind power prediction system, a data analyzer, a control module, a storage battery, a wind power generation field, and a breaker. The data collector acquires active power outputted by the wind power generation field and a charged state of the storage battery, and sends a result to the wind power prediction system and the data analyzer. According to received data, actual data of a previous time segment and a predicted value, the wind power prediction system carries out prediction on a present time segment and sends a result to the data analyzer. According to the received data, the data analyzer carries out comparison determination and outputs a control instruction to the control module according to a comparison result. An output terminal of the control module connects with the breaker which connects the storage battery with an electrical network. The control module controls connection and disconnection of the breaker according to an instruction. According to the system, power fluctuation and cell capacity can be reduced, and electric energy quality can be improved. The invention also discloses a storage battery control method.

A virtual energy storage based electric heating micro-grid connecting line power fluctuation suppression method is disclosed. Firstly, a virtual energy storage system model of fusion heat pump, gas turbine and building energy storage is constructed by means of heat storage capacity of building on user side of electric heating micro-grid. By collecting the real-time power of renewable energy and user load, Considering the state of charge of supercapacitor and the state of virtual energy storage system, the target power of tie-line is determined to realize the power smoothing of tie-line in micro-grid. Finally, the final output of controllable equipment is given by calculating and correcting the pre-output of controllable equipment. The invention can regulate the output of the virtual energystorage system while meeting the constraint of the room temperature, and distributes the fluctuating power of the tie line of the electric heating micro-grid between the virtual energy storage (heatpump, micro-gas turbine) and the super capacitor in cooperation with the charge and discharge of the super capacitor, thereby improving the absorbing capacity of the distributed power supply and optimizing the comprehensive utilization efficiency of the energy.

The invention provides an AC/DC hybrid microgrid modular structure and a multi-mode operation mode, and belongs to the field of microgrid modular design and operation control. An AC/DC hybrid microgrid is divided into six modules, and the type and the control mode of distributed power supplies or energy storage in each module are determined. The six modules are a PCC module, an AC microgrid regulation module, an AC microgrid non-regulation module, a DC microgrid regulation module, a DC microgrid non-regulation module and an interconnection module. Double guarantee is provided for the relatively "weak" DC microgrid in the grid-connected microgrid through the conversion operation among the DC microgrid automatic control mode in the grid-connected state, the interconnection module control mode and the island mode in the off-grid state. The controllable distributed power supplies, energy storage and interconnected converters in different modules are combined to be controlled and the microgrid is accessed to a large power grid with a variable power load or power supply. The dependency of MGCC on the communication system is reduced by using a two-layer control method including a module lay and a microgrid layer.

The invention discloses a method and system for stabilizing power fluctuations of a microgrid. The method comprises the steps of firstly acquiring the distributed renewable energy generation power, the connecting line node power, the charging and discharging time of each battery, the charging current of each battery and the battery charge quantity compensation amount; then calculating the charge quantity of each battery at the current moment according to the charging and discharging time, the charging current and the compensation amount; then calculating the output/input power of each battery and the output/input power of a supercapacitor according to the charge quantity of each battery at the current moment, the connecting line node power and the distributed renewable energy generation power, and thus determining the actual output/input power of a hybrid energy storage system. By adopting the method or system provided by the invention, the charge quantity of lithium batteries in the hybrid energy storage system can be acquired in real time, the actual charging and discharging energy of the hybrid energy storage system is accurately predicted, and thus the power fluctuations in the microgrid are stabilized accurately and effectively.