Research On Power Quality Management Strategy After Large-scale Application Of Power Substitute Load

With the development of economy and society,China’s energy demand continues to grow,and environmental pollution is increasing day by day.It has become an urgent need to promote the development of clean energy.The implementation of electric energy substitution technology is of great significance in optimizing the energy consumption structure and implementing the national energy strategy.At present,the electric energy substitution market has begun to enter a stage of rapid development.The large-scale application of electric energy substitution technology has led to aggravation of power quality pollution in the regional distribution network,which affects and hinders the smooth promotion of electric energy substitution projects.The thesis focuses on the power quality problems after the large-scale application of electric kilns,decentralized electric heating,and large-capacity shore power replacement loads.The thesis takes the optimized configuration of the treatment device as the research goal,establishes a comprehensive resource optimization model for power quality management,and completes the distribution network management plan under different load scales.The specific work of the thesis is as follows:(1)Aiming at the power quality problems of low voltage,high harmonic distortion rate and high reactive power loss caused by the large-scale access of electric kiln loads to the distribution network,a two-stage power grid comprehensive resource optimization configuration considering reactive power optimization and harmonic control is proposed.In the first stage,a reactive power optimization model is established with the goal of minimizing active power loss,voltage deviation and equipment cost.In the second stage,an optimal configuration model of harmonic control is established with the cost of the active filter as the goal.The improved particle swarm algorithm and genetic algorithm are used to solve the multi-objective optimization,and the model is simulated and verified with calculation examples.(2)Aiming at the power quality problems of low voltage,high harmonic distortion rate and aggravated three-phase imbalance after the large-scale integration of decentralized electric heating,a two-tier power grid integrated resource optimization model for power quality management and load optimization dispatch is established.The upper-level planning takes the investment cost of the treatment device,the operation and maintenance cost,and the minimization of the loss of the distribution network as the planning goal.The decision variables are the capacity configuration of the treatment device and the number and location of the commutation switch configuration.The lower layer is load optimization scheduling,with the minimum number of action switches and the minimum three-phase unbalance as the planning goals,and the decision variable is the state of the commutation switch.Establish a joint simulation platform based on Matlab and Open DSS,and use an improved particle swarm algorithm to solve the problem.Finally,a calculation example is used to verify the planned governance plan.(3)Aiming at the problem of high harmonic distortion rate after large-scale connection of large-capacity shore power installations,an optimization model for power quality management of distribution network is established.Taking the best harmonic suppression effect and the smallest investment cost of the power quality control device as the objective function,multi-objective optimization of the capacity configuration and parameter selection of the harmonic control device of the port distribution network is carried out.Combine the multi-objective particle swarm algorithm with the actual application environment and analyze the calculation examples.Through the research of the above content,the thesis is of great significance to promote electric energy substitution projects and improve our electrification level.