34results about How to "Reduce light rejection" patented technology

The invention discloses an active distribution network planning method, which includes establishing a photovoltaic power generation output model and reducing operation scenarios; establishing an optimization model for grid construction of a power distribution company; establishing an electricity price adjustment model for a power distribution company; and generating a grid structure of a distribution network ; Solve the generated model to get the final active distribution network planning scheme. The method of the present invention can solve the problem of active distribution network grid expansion planning, can select the optimal distribution network line construction scheme, reduce investment costs, improve the consumption capacity of distributed power sources, reduce light abandonment, and effectively reduce network loss. Improve the economics of the distribution network.

The invention discloses a method of improving tracking photovoltaic power generation output characteristics based on hydrogen and battery hybrid energy storage. The method comprises the steps of: S100, formulating a next-day photovoltaic output plan according to the short-term photovoltaic prediction power, and correcting the next-day photovoltaic output plan according to the SOC of an energy storage battery at night of the day, S200, dividing scheduling modes into main scheduling and coordinated scheduling according to the SOC of the energy storage battery, selecting a different scheduling mode according to the state of charge interval of the SOC of the energy storage battery in real-time scheduling, and tracking the photovoltaic planned output, and S300, taking the photovoltaic output plan as the premise by next-day scheduling and controlling a hydrogen electrolysis cell and the energy storage battery for charge and discharge according to the scheduling mode. The method can perform flexible switching between a main scheduling scheme and a coordinated scheduling scheme, realizes accurate tracking of photovoltaic planned output, reduces fluctuation of grid-connected input power ofa photovoltaic power station, relieves frequency modulation pressure of a system unit, and improves the utilization rate of light energy.

The invention discloses a network source coordination virtual synchronous machine control method for an integrated optical storage system. The method is based on an integrated optical storage system with a two-stage structure, in which photovoltaic and energy storage use the same inverter to connect to the grid, and photovoltaic and The energy storage batteries are respectively connected in parallel to the DC bus of the inverter through their respective DC / DC converters, and the two DC / DC converters and the inverter are controlled by a virtual synchronous machine control scheme coordinated by the network source. The inverter realizes inertia control and reactive power droop control; the DC / DC converter of the battery realizes active power droop control; when the DC capacitor voltage is not higher than the upper limit value U dcuplimit When , the photovoltaic DC / DC converter realizes the maximum power output control; when the DC capacitor voltage exceeds the upper limit value U dcuplimit , the photovoltaic DC / DC converter automatically enters the control of light abandonment. The invention can not only provide inertial and droop support for the power grid, but also automatically adjust the power output to the power grid when the source side power fluctuates, thereby reducing light curtailment and reducing the demand for energy storage battery capacity.

The present invention proposes a micro-grid frequency control method that minimizes power generation costs, which belongs to the technical field of power system operation and control. The method includes: establishing respective power generation cost functions and power generation cost micro-increase rate functions; Power output limitation constraints, and energy constraints of energy storage devices: adjust the synchronous governor of the generator and the controller of the inverter, perform frequency modulation once, perform frequency modulation twice after time intervals, collect system frequency and calculate second frequency modulation each time The total amount of active power set value adjustments is distributed to all distributed power sources or energy storage devices participating in frequency regulation, and the active power set value adjustment amount and the original set value are summed as For the new active power setting value, perform frequency modulation again to maintain the system frequency stability. The method of the invention can maximize the utilization rate of renewable energy, can improve the absorbing capacity of the microgrid renewable energy, and is convenient to realize and simple to control.

The invention relates to a method for calculating the time-varying reliability of a power distribution system considering the randomness of demand-side resource response, comprising the following steps: Step 1. Establishing physical models of different demand-side resources according to the physical characteristics of the demand-side resources; Step 2 1. Considering the random failure of demand-side resource equipment, establish a response volume model for different demand-side resources; step 3, calculate the response volume after aggregation of demand-side resources; step 4, establish a response volume model after aggregation of demand-side resources considering random processes , to obtain the probability of the demand-side resource response in different states; step 5, calculate the time-varying reliability value of the distribution system considering the randomness of the demand-side resource response. The invention can accurately and quantitatively evaluate the influence of the demand-side resource response randomness on the reliability of the power distribution system.

The invention provides a power peak shaving method, a dispatch center and a power peak shaving system. The method includes: obtaining the next day's predicted load, the next day's predicted new energy output, and the next day's high-energy load information that can participate in dispatching; according to the obtained The next day's forecasted load, the next day's forecasted new energy output, and the next day's high-energy load information that can participate in dispatching can generate a day-ahead dispatching plan under the peak-shaving mode in which only conventional energy power plant units participate; Whether there is a situation of discarding new energy output on a daily basis; if so, generate a day-ahead scheduling plan in which conventional energy power plant units and high energy loads participate together; based on the day-ahead scheduling plan and battery energy storage device output plan for conventional energy power plants and new energy power plants Intra-day correction can improve the ability to track load changes, increase the flexibility of adjustment, reduce the limitations of discrete adjustment of high-energy loads on peak regulation, and effectively reduce system operating costs.

The invention relates to an independent light-storage micro-grid topology for interconnected operation. The independent light-storage micro-grid topology is formed by connecting an energy storage system, a distributed photovoltaic power generation system and a load in parallel; and the distributed photovoltaic power generation system and the load are connected with an AC bus in parallel. The independent light-storage micro-grid topology is characterized in that the output end of an energy storage battery pack in the energy storage system is connected to one end of an isolating switch; the other end of the isolating switch is connected with the input end of a DC / DC converter; the output end of the DC / DC converter is connected with the DC side of a DC / AC energy storage converter, and the connecting line is taken as a DC bus of independent light-storage micro-grids; and the AC output of the DC / AC energy storage converter is taken as an AC bus of independent light-storage micro-grids. When the independent light-storage micro-grids work independently, the DC / DC converter controls the voltage of the DC bus of the independent light-storage micro-grids, and the DC / AC energy storage converter controls the voltage of the AC bus of the independent light-storage micro-grids; when the independent light-storage micro-grids are interconnected, the two independent light-storage micro-grids are connected in parallel by utilizing an interconnecting switch; and the DC / DC converter controls the voltages of the micro-grids by adopting an active voltage droop control method.

The invention discloses a distribution network reactive power optimization method for photovoltaic reactive power partition pricing, which includes proposing a controllable photovoltaic reactive power partition pricing model, with the minimum reactive power comprehensive cost, the minimum active network loss and voltage deviation as the optimization target, Construct active-reactive power optimization model of distribution network including response to PV inverter reactive power partition price, static var compensator SVC dynamic compensation, on-load voltage regulation equipment OLTC tap and capacitor bank switching; adopt second-order cone programming The nonlinear terms in the model are processed by mathematical methods such as the large M method, and finally a mixed integer second-order cone programming model for the coordinated optimization of active and reactive power of the distribution network with controllable photovoltaics under the power market environment is obtained, and the Bund The Sri Lankan decomposition method solves the model segmentation. The invention rationally and coordinately utilizes the reactive power capacity of the photovoltaic inverter and the reactive power support capability of the original discrete equipment of the distribution network, reduces active power network loss, and ensures user voltage quality.

The invention relates to a photovoltaic grid-connected inverter control method, in particular to a photovoltaic grid-connected inverter control method for preventing voltage out-of-limit of a low-voltage distribution network by considering the influence of line impedance and operating environments on a photovoltaic inverter. Voltage out-of-limit of a grid connection point of the inverter can be prevented, and light discarding amount can be decreased as far as possible by the aid of the residual capacity of the inverter on the premise of ensuring the voltage quality of the grid connection point when voltage exceeds upper limit. Compared with a traditional method, when the voltage of the grid connection point exceeds the upper limit, an active and reactive power matching method is designed by reverse thinking on the premise of ensuring the voltage quality, and the light discarding amount is decreased by the residual capacity of the inverter.

The invention discloses a capacity optimization configuration method for urban rail transit photovoltaic energy storage systems. According to the operation characteristics of urban rail transit with large morning and evening peak loads, a time-sharing operation strategy is formulated to determine the operation of photovoltaics, energy storage and power grids in different periods status; study typical daily load curves and photovoltaic output curves for output adaptability analysis, integrate photovoltaic and energy storage time-sharing operation characteristics and output adaptability analysis, establish an optimization model with voltage fluctuation and economy as the objective function, and pass the weighted value The multi-objectives are converted into single-objective optimization functions by means of a single-objective optimization function, and the particle swarm optimization algorithm is used to solve the problem to obtain the optimal configuration of the energy storage capacity of the system. The invention is beneficial to promote the energy saving and emission reduction of the urban rail system and the consumption of local photovoltaics, and at the same time reduce the network voltage fluctuations to improve the power quality of the traction side, time-sharing operation and use of energy storage to cut peaks and valleys of photovoltaics and load peaks Improve system economy.