Abstract: The disclosure provides a stochastic look-ahead dispatch method for power system based on Newton method, belonging to power system dispatch technologies. The disclosure analyzes historical data of wind power output, and uses statistical or fitting software to perform Gaussian mixture model fitting. A dispatch model with chance constraints is established for system parameters. Newton method is to solve quantiles of random variables obeying Gaussian mixture model, so that chance constraints are transformed into deterministic linear constraints, thus transforming original problem to convex optimization problem with linear constraints. Finally, the model is solved to obtain look-ahead dispatch. The disclosure employs Newton method to transform chance constraints containing risk level and random variables into deterministic linear constraints, which effectively improves model solution efficiency, and provides reasonable dispatch for decision makers.

Abstract: The present disclosure proposes a decomposition-coordination voltage control method for wind power to be transmitted to a nearby area via flexible DC. The method includes: initializing parameters; sending the parameters to wind power farms; for each of the wind power farms, establishing a voltage control optimization sub-model; solving the voltage control optimization sub-model to obtain a first optimal result; for the control center, establishing a voltage control optimization main model; solving the voltage control optimization main model to obtain a second optimal result; calculating a determination index based on the first optimal result and the second optimal result; and determining whether the determination index is convergent to an admissible value, if no, updating the parameters and returning to establishing the voltage control optimization sub-model.

Abstract: The disclosure provides a method for planning a power distribution network, an apparatus for planning a power distribution network, and a storage medium. The method includes: establishing a model for planning the power distribution network, the model including a target function and constraints, the target function for minimizing a cost of the power distribution network when branches, and nodes are installed into the power distribution network, the nodes including transformers and substations, the constraints including a power balance constraint of the power distribution network, a power constraint of the branches, a power constraint of the transformers, a radial operation constraint of the power distribution network, a fault constraint, a calculation constraint of indices of a reliability, a constraint of the indices of the reliability, and a logic constraint; and solving the model to determine whether the branches and the nodes are installed into the power distribution network.

Abstract: The present disclosure provides a scheduling method for a power system based on flexible HVDC (high-voltage direct current) and a pumped storage power station, which belongs to a field of power system control technologies. The method is applicable in a power system having a flexible HVDC system and a pumped storage power station. By establishing a scheduling model for the power system, which contains an objective function and multiple constraints, and solving the scheduling model, a capability of the pumped storage power station is used to adjust the unstable output of the renewable energy power generator and stabilize fluctuant of the renewable energy power generation, such that a power incoming into a load center presents a stable ladder pattern and an optimal scheduling scheme can be obtained.

Abstract: The disclosure provides a stochastic dynamical unit commitment method for power system based on solving quantiles via Newton method, belonging to power system technologies. The method establishes a unit commitment model with chance constraints for power system parameters. Quantiles of random variables obeying mixed Gaussian distribution is solved by Newton method, and chance constraints are transformed into deterministic linear constraints, so that original problem is transformed into mixed integer linear optimization problem. Finally, the model is solved to obtain on-off strategy and active power plan of units. The disclosure employs Newton method to transform chance constraints containing risk level and random variables into deterministic mixed integer linear constraints, which effectively improves the model solution efficiency, eliminates conservative nature of conventional robust unit commitment, provides reasonable dispatch basis for decision makers.

Abstract: A method for calculating a voltage stability margin of a power system considering electric-gas system coupling is provided. The method includes: establishing constraint equations for stable and secure operation of an electric-gas coupling system; establishing a continuous energy flow model of the electric-gas coupling system using a load margin index ? based on a correlation between an electric load of the power system and a natural gas load of the natural gas system; setting inequality constraints for the stable and secure operation of the electric-gas coupling system based on the limits of pressure and gas supply amount of the natural gas system; and solving the energy flow equation established based on the constraints and the continuous energy flow model to obtain the voltage stability margin of the power system considering electric-gas system coupling.

Abstract: The present disclosure relates to a method, an apparatus and a storage medium for controlling a combined heat and power system, belonging to the field of power system technologies. The method discloses: establishing a decision model, the decision model including an objective function aiming to minimize a total cost of the first generators and the second generators, and constraints with respect to the first generators, the second generators and the heating exchange stations; solving the decision model to acquire operation states of the first generators, operation states of the second generators, and operations states of the heating exchange stations; and controlling the combined heat and power system, based on the operation states of the first generators, the operation states of the second generators, and the operations states of the heating exchange stations.

Abstract: The present disclosure provides a method and a device for solving an optimal power flow in a power supply system. A second convex model of the optimal power flow is established. A relaxation variant sum e according to the second convex model is determined. It is judged whether the relaxation variant sum e is greater than a preset threshold. If the relaxation variant sum e is greater than the preset threshold, the second convex model of the optimal power flow is established. If the relaxation variant sum e is not greater than the preset threshold, the solution of the second convex optimal model is determined as a feasible solution of the optimal model of the optimal power flow.

Abstract: The disclosure provides a stochastic look-ahead dispatch method for power system based on Newton method, belonging to power system dispatch technologies. The disclosure analyzes historical data of wind power output, and uses statistical or fitting software to perform Gaussian mixture model fitting. A dispatch model with chances constraints is established for system parameters. Newton method is to solve quantiles of random variables obeying Gaussian mixture model, so that chances constraints are transformed into deterministic linear constraints, thus transforming original problem to convex optimization problem with linear constraints. Finally, the model is solved to obtain look-ahead dispatch. The disclosure employs Newton method to transform chance constraints containing risk level and random variables into deterministic linear constraints, which effectively improves model solution efficiency, eliminates conservative nature of conventional robust, provides reasonable dispatch for decision makers.

Abstract: The disclosure provides a stochastic dynamical unit commitment method for power system based on solving quantiles via Newton method, belonging to power system technologies. The method establishes a unit commitment model with chance constraints for power system parameters. Quantiles of random variables obeying mixed Gaussian distribution is solved by Newton method, and chance constraints are transformed into deterministic linear constraints, so that original problem is transformed into mixed integer linear optimization problem. Finally, the model is solved to obtain on-off strategy and active power plan of units. The disclosure employs Newton method to transform chance constraints containing risk level and random variables into deterministic mixed integer linear constraints, which effectively improves the model solution efficiency, eliminates conservative nature of conventional robust unit commitment, provides reasonable dispatch basis for decision makers.

Abstract: A state estimation method for a heat supply network in a steady state based on a bilateral equivalent model is provided. The method includes: establishing the bilateral equivalent model based on a mass flow rate in each supply branch of the heating network, a mass flow rate in each return branch of the heating network, a mass flow rate in each connecting branch of the heating network, a pressure and a temperature of each node in the heating network, wherein each heat source is configured as a connecting branch and each heat load is configured as a connecting branch; and repeatedly performing a state estimation on the heating network based on the bilateral equivalent model, until a coverage state estimation result is acquired.

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: 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 dispatching method and a dispatching device for an integrated transmission and distribution network. The integrated transmission and distribution network include a transmission network and at least one distribution network. The method includes: establishing a dispatch model of the integrated transmission and distribution network; solving the dispatch model to obtain dynamic dispatch parameters for the integrated transmission and distribution network, in which the dynamic dispatch parameters comprise a boundary transferred power from the transmission network to each of the at least one distribution network, and power outputs of all generators in the transmission network and each of the at least one distribution network; and dispatching the integrated transmission and distribution network based on the boundary transferred power and the power outputs of all the generators in the transmission network and each of the at least one distribution network.

Abstract: The present disclosure provides a dispatch method and apparatus for controlling a combined heat and power CHP system. The CHP system includes CHP units, non-CHP thermal units, wind farms and heating boilers; the CHP units, the non-CHP thermal units and the wind farms form an electric power system EPS of the CHP system; the CHP units and the heating boilers form a central heating system CHS of the CHP system; and the EPS and the CHS are isolable. The method includes: establishing a combined heat and power dispatch CHPD model, an objective function being a minimizing function of a total generation cost of the CHP units, the non-CHP thermal units, the wind farms and the heating boilers; solving the CHPD model based on Benders decomposition to obtain dispatch parameters for the EPS and the CHS; and controlling the EPS and the CHS according to the corresponding dispatch parameters respectively.

Abstract: The present disclosure provides a dispatching method and a dispatching device for an integrated transmission and distribution network. The integrated transmission and distribution network includes a transmission network and at least one distribution network. The method includes: establishing a dispatch model of the integrated transmission and distribution network, in which dispatch model includes an objective function and constraints, the objective function is a minimizing function of a total generation cost of the transmission network and the at least one distribution network under the constraints; solving the dispatch model to obtain dynamic dispatch parameters for the integrated transmission and distribution network; and dispatching the integrated transmission and distribution network according to the dynamic dispatch parameters.

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 provides a method and a device for controlling an active distribution network, relating to the field of power system operation and control technology.

Abstract: The present disclosure provides a method and a device for controlling a distributed generator in a distribution system. The method includes: extracting a first statistic feature of a load at each bus; extracting a second statistic feature of a distributed generator at each bus; establishing a probability distribution set of each first and second statistic feature; determining security constraints of the distribution system; obtaining a bilinear matrix inequality constraint by using a C-VaR approximation algorithm and a duality algorithm based on the probability distribution set and on the security constraints; determining an objective function to maximize a total installed capacity of the distributed generators; solving the objective function according to the bilinear matrix inequality constraint to obtain an installed capacity of each distributed generator; and controlling an access of each distributed generator according to the installed capacity.

Abstract: The present disclosure relates to a partition method and a partition device for a power system and belongs to a field of an evaluation and control of a power system. The method includes steps of: obtaining a quasi-steady sensitivity matrix according to generators participating in automatic voltage control and load buses in the power system; obtaining a power system model according to the quasi-steady sensitivity matrix and the load buses; determining principal component vectors and principal component singular values according to the power system model; determining a principal component vector dominated by each generator according to the principal component vectors and the principal component singular values; and partitioning the generators dominating a same principal component vector to a partition, and partitioning the load buses according to a partition result for the generators.