Aiming at the synergy between a system’s carbon emission reduction demand and the economy of peak shaving operation in the process of optimizing the flexible resource peaking unit portfolio of a multi-energy power system containing large-scale electric vehicles, this paper proposes a low-carbon optimal scheduling model for peak shaving resources in multi-energy power systems considering large-scale access for electric vehicles. Firstly, the charging and discharging characteristics of electric vehicles were studied, and a comprehensive cost model for electric vehicles, heat storage, and hydrogen storage was established. At the same time, the carbon emission characteristics of multi-energy power systems and their emission cost models under specific carbon trading mechanisms were established. Secondly, the change characteristics of the system’s carbon emissions were studied, and a carbon emission cost model of multi-energy power was established considering the carbon emission reduction demand of the system. Then, taking the carbon emission of the system and the peak regulating operation costs of traditional units, energy storage, and new energy unit as optimization objectives, the multi-energy power system peak regulation multi-objective optimization scheduling model was established, and NSGA-II was used to solve the scheduling model. Finally, based on a regional power grid data in Northeast China, the improved IEEE 30 node multi-energy power system peak shaving simulation model was built, and the simulation analysis verified the feasibility of the optimal scheduling model proposed in this paper.
The Axial Magnetic Field (AMF) applied to the arc vacuum column in the vacuum tube can make the vacuum arc keeping in diffusion state, provided that the short circuit current to be interrupt is within a critical value. In the results, the breaking ability of Vacuum Interrupters can be highly improved with the help of the AMF. The experimental study has proved that the AMF should be sufficient strong and have optimum distribution, in order to improve the breaking capacity of vacuum circuit breaker. This paper presents a novel axial magnetic contact with the concave axial magnetic field distribution and its 3-d simulation.
Nowadays, there are a lot of EDA simulation tools. Each of them has its own functions and features. WEBENCH is a web based, and easy to use, design and simulation tool. The design and simulation method of switching power using WEBENCH tool is given in this paper. A complete boost topology design example of switching power is introduced. Electrical simulations of output voltage are given. Compensation for current mode switching power is also discussed and calculated by WEBENCH tool. Thermal simulations of print circuit board are analyzed.
The state evaluation of power equipment is an important basis for maintenance scheduling. This paper starts from the performance state data of power transformer and aims to study the matrix model and mathematical analysis method that is applicable to the state evaluation parameter system of power equipment in 220 kV substations. Different from the traditional threshold deduction method, this paper is more inclined to propose a closed loop model by finding the correlation among the internal key parameters of the system by reducing the dimension of the state matrix and increasing the dimension of iterations. This paper presents the basic state evaluation parameter system from various aspects which are based on the multi-source information of 220 kV substations. The dimensionality reduction of the matrix is carried out for the criterion matrix of the nature.
The chaos characteristic of vacuum circuit breaker (VCB) under different interruption conditions in synthetic circuit experiment is researched. Using four parameter and two parameter method, comparing the influence of the metal vapor arc model, the variations of voltage and current for different VCBs are obtained. And the chaos in synthetic circuit experiment for the demonstrated VCBs based on the Lyapunov exponent (LE) method has been analyzed.
Based on the theories of fractal and gas discharge, microscopic morphology of vacuum arc, the process of arc formation and development of discharge channel in the vacuum circuit breaker are simulated. The effects of temperature and electromagnetic field on the arc are also considered. The opening stroke is 10 mm in our work. Voltage is 75 kV, and current is 1 kA. The effects of temperature on the arc radius, the role of self-generated magnetic fields and thermal conduction are simulated here. The results show that electron density and the coefficient of heat conduction are increased gradually. Average temperature increases at first and decreases latter, then collision coefficient enhances. The radius of arc also increases in the stage of arc formation and development. The arc radius contract and stable arc forms after breakdown.
Low-pressure bypass system is an important part of large-scale intermediate-reheat unit.The internal leakage of low-pressure bypass is a common problem in steam turbine.Main characteristics of internal leakage and its impact to the security and economy of the unit have been analyzed in the paper.Countermeasures against the internal leakage in the low-pressure bypass have been put forward in the paper based on the experience of handling the internal leakage of many LP bypass systems for 600MW units.
Aiming at the problem of source-load incoordination of combined heat and power (CHP) system caused by the high electro-thermal coupling strength, a optimal operation strategy of combined heat and power system based on electric thermal storage boiler and thermal inertia is proposed. Firstly, the internal heat transfer model of the solid electric thermal storage boiler was studied, and the three-dimensional numerical simulation of the temperature field of the thermal storage body was performed. Then, the thermal inertia model of the heating network and the building is established. On this basis, a coordinated optimization model of CHP system based on thermal storage boiler and thermal inertia is established with the goal of minimizing the operating cost of the system. The results show that the optimization strategy proposed in this paper can effectively reduce the electro-thermal coupling strength and improve the flexibility and economy of the CHP system.
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