Abstract: A single-stage enthalpy enhancing rotary compressor and an air conditioner having same. The single-stage enthalpy enhancing rotary compressor includes: at least one single-stage cylinder, a rotator, an upper flange, and a lower flange. The rotator is arranged inside the cylinder and is rotatable, a compression chamber is formed between the rotator and an inner peripheral wall of the cylinder, a vapor injection opening is defined in at least one of the upper flange the lower flange, and the vapor injection opening is configured to supply gas outside the compressor to the compression chamber directly. According to the present disclosure, two-stage compression is realized without adding an extra cylinder, thereby effectively enhancing a circulation of refrigerant, improving cooling performance of the air conditioner under high environmental temperatures.

Abstract: The present disclosure provides a method for planning a distribution network with reliability constraints based on a feeder corridor, including determining installation states of respective elements in the distribution network; determining an objective function, the objective function being an objective function of minimizing a total investment cost of the distribution network; obtaining fault-isolation-and-load-transfer time and fault recovery time in a case where the feeder segment of each feeder line that is contained in each feeder corridor fails; determining constraint conditions including reliability constraints; building a distribution network planning model according to the objective function and the constraints; and solving the distribution network planning model built to obtain optimal solutions as planning states and reliability indexes to plan the distribution network.

Abstract: The disclosure relates to a two-side stochastic dispatching method for a power grid. By analyzing historical data of wind power, the Gaussian mixture distribution is fitted by software. For certain power system parameters, a two-side chance-constrained stochastic dispatching model is established. The hyperbolic tangent function is used to analyze and approximate cumulative distribution functions of random variables in the reserve demand constraint and the power flow constraint, to convert the two-side chance constraint into a deterministic constraint. The disclosure can have the advantage of using the hyperbolic tangent function to convert the two-side chance constraint containing risk levels and random variables into the solvable deterministic convex constraint, effectively improving the solution efficiency of the model, and providing decision makers with a more reasonable dispatching basis.

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 disclosure relates to a two-side stochastic dispatching method for a power grid. By analyzing historical data of wind power, the Gaussian mixture distribution is fitted by software. For certain power system parameters, a two-side chance-constrained stochastic dispatching model is established. The hyperbolic tangent function is used to analyze and approximate cumulative distribution functions of random variables in the reserve demand constraint and the power flow constraint, to convert the two-side chance constraint into a deterministic constraint. The disclosure can have the advantage of using the hyperbolic tangent function to convert the two-side chance constraint containing risk levels and random variables into the solvable deterministic convex constraint, effectively improving the solution efficiency of the model, and providing decision makers with a more reasonable dispatching basis.

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 planning method for a power distribution automation system based on a reliability constraint is provided. The method includes: defining installation states of components and principles of a fault isolation, a load transfer and a fault recovery after a branch fault occurs; establishing a reliability evaluation optimization model for a power distribution network based on a mixed integer linear programming, the reliability evaluation optimization model comprising a target function and constraint conditions; solving the reliability evaluation optimization model to obtain an optimum planning scheme; and planning the power distribution automation system based on the optimum planning scheme.

Abstract: The present disclosure provides a method for optimizing transformation of automation equipment in a power distribution network based on reliability, including determining installation states of respective components in the power distribution network and operation criterions for fault isolation, load transfer and fault recovery after a fault occurred in a feeder segment; determining a target function which is a target function for minimizing a total transformation cost of the power distribution network; determining constraint conditions including reliability constraints; establishing an optimization model for evaluating the reliability of the power distribution network based on the reliability constraints in accordance with the target function and the constraints; and solving the established optimization model for evaluating the reliability of the power distribution network based on the reliability constraints to obtain optimal solutions as optimization results of the automation transformation state of the cir

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: 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: 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: The present disclosure provides a method for planning a distribution network with reliability constraints based on a feeder corridor, including determining installation states of respective elements in the distribution network; determining an objective function, the objective function being an objective function of minimizing a total investment cost of the distribution network; obtaining fault-isolation-and-load-transfer time and fault recovery time in a case where the feeder segment of each feeder line that is contained in each feeder corridor fails; determining constraint conditions including reliability constraints; building a distribution network planning model according to the objective function and the constraints; and solving the distribution network planning model built to obtain optimal solutions as planning states and reliability indexes to plan the distribution network.

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: 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 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: 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 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 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.