Abstract:
An online voltage control method for coordinating multi-type reactive power resources is provided. First, a linearized power flow equation of branch reactive power is established, and an online voltage control model of multi-type reactive power resources including an objective function and constraint conditions is constructed. The constraint conditions includes generator reactive power constraints, reactive power compensator constraints, transformer tap position constraints, a nodal reactive power balance constraint, and slack contained nodal voltage constraints. Then, an optimization result of voltage control is obtained by solving the model. The method makes full use of reactive voltage operation characteristics of a power grid, constructs a practical online solution model for reactive voltage control of large power grid of coordinating multiple reactive power resources, and under a condition of acceptable accuracy loss, takes in account safety of power grid operation, economy of reactive power resource actions and high reliability of online operation.
Abstract:
The disclosure provides power distribution network reliability index calculation method based on mixed integer linear programming. The method includes: establishing a model for optimizing reliability indexes of a power distribution network based on a mixed integer linear programming model, wherein the model comprises an objective function and constraint conditions, the objective function is for minimizing a system average interruption duration index (SAIDI); solving the model based on the objective function and the constraint conditions to obtain reliability indexes of the power distribution network; and controlling operation of the power distribution network based on the reliability indexes.
Abstract:
A reactive power-voltage control method for integrated transmission and distribution networks is provided. The reactive power-voltage control method includes: establishing a reactive power-voltage control model for a power system consisting of a transmission network and a plurality of distribution networks; performing a second order cone relaxation on a non-convex constraint of the plurality of distribution network constraints to obtain the convex-relaxed reactive power-voltage control model; solving the convex-relaxed reactive power-voltage control model to acquire control variables of the transmission network and control variables of each distribution network; and controlling the transmission network based on the control variables of the transmission network and controlling each distribution network based on the control variables of the distribution network, so as to realize coordinated control of the power system.
Abstract:
A method for estimating a state of a combined heat and power system is provided. The method include: establishing an objective function; establishing constraints under a steady-state operating stage; converting the objective function and the constraints by utilizing a Lagrangian multiplier to obtain a Lagrange function; obtaining a steady-state estimation result of the combined heat and power system based on the Lagrange function; calculating an energy transmission delay produced by each pipe; establishing a dynamic constraint of each pipe based on the steady-state estimation result and the energy transmission delay; converting the objective function, the constraints, and the dynamic constraint by utilizing the Lagrangian multiplier to update the Lagrange function; obtaining a dynamic-state estimation result of the combined heat and power system during a dynamic-state operating stage of the combined heat and power system based on the updated Lagrange function.
Abstract:
An intra-day rolling scheduling method for an integrated heat and electricity system including: establishing an objective function for scheduling of the integrated heat and electricity system, the objective function aiming to make operating costs of the integrated heat and electricity system to be a minimum; establishing constraints for a steady-state safe operation of the integrated heat and electricity system; and solving the objective function based on the constraints by an interior point method, to obtain an active power and a heating power of each combined heat and power unit, an active power of each thermal power unit, a heating power of each heat pump, and an active power consumed by each circulating pump.
Abstract:
A reactive power optimization method for integrated transmission and distribution networks related to a field of operation and control technology of an electric power system is provided. The reactive power optimization method includes: establishing a reactive power optimization model for a transmission and distribution network consisting of a transmission network and a plurality of distribution networks, in which the reactive power optimization model includes an objective function and a plurality of constraints; performing a second order cone relaxation on a non-convex constraint of a plurality of distribution network constraints of the plurality of constraints; and solving the reactive power optimization model by using a generalized Benders decomposition method so as to control each generator in the transmission network and each generator in the plurality of distribution networks.
Abstract:
The present disclosure provides a frequency control method for a micro-grid and a control device. The method includes: determining a middle parameter at iteration k; determining a local gradient parameter at iteration k according to the cost increment rate at iteration k, the frequency difference between iterations k and k+1, and communication coefficients; performing a quasi-Newton recursion according to the middle parameter and local gradient parameter to acquire a recursion value; determining the cost increment rate at iteration k+1 according to the recursion value; determining an adjustment value of an active power according to the cost increment rate at iteration k+1; adjusting the active power according to the adjustment value if the adjustment value satisfies a constraint condition and judging whether the difference is smaller than a predetermined threshold; executing k=k+1 if yes and stopping the frequency control if no.
Abstract:
The present disclosure relates to a method and an apparatus for controlling a voltage in a wind farm. The method includes: collecting measured values of parameters as initial values of the prediction values; inputting the initial values into a preset control model for optimizing a model predictive control; solving the preset control model to obtain a first solution sequence of the reactive power setting values of the wind turbines and a second solution sequence of the terminal voltage setting values of the static var generators; and sending first values in the first solution sequence to the wind turbines and first values in the second solution sequence to the static var generators, such that a voltage control in the wind farm is realized.
Abstract:
A security and economy coordinated automatic voltage control method based on a cooperative game theory is provided. The method includes: establishing a multi-objective reactive voltage optimizing model of a power system; resolving the multi-objective reactive voltage optimizing model into an economy model and a security model; solving the economy model and the security model based on the cooperative game theory to obtain the automatic voltage control instruction; and performing an automatic voltage control for the power system according to the automatic voltage control instruction.
Abstract:
A method for mechanochemical treatment of solid wastes containing perfluorinated or polyfluorinated compounds is provided. It belongs to the field of environment-polluting wastes treatment, and comprises the following steps: mixing the solid waste containing perfluorinated or polyfluorinated compounds with the defluorination reagent under normal temperature and pressure conditions, putting the mixture into a planetary high-energy ball milling reactor; adopting the mechanochemical reaction to realize high-effective degradation and defluorination of perfluorinated or polyfluorinated compounds. When being adopted to degrade perfluorinated or polyfluorinated compounds, this method enjoys such advantages as simple treatment procedure, mild reaction conditions (conducted under normal temperature and pressure conditions), lower energy consumption and operating cost, complete degradation and defluorination of the target pollutants, completely inorganic and harmless end products and free of liquid or gas byproducts.