Research On Typical Transformer Area Based Pre-Judgement Methods Of Consumer Low Voltage

With the advancement of the country's new urbanization process,China's urban and rural economies have entered a fast-growing orbit.The demand for electricity in rural areas has increased substantially.China has gradually increased its efforts in the construction of power grids,and the power grid has achieved considerable development.At the same time,the construction of the transmission grid was over-emphasized in the development process of power grids,while the relevant configuration of the distribution network was neglected,which makes the low-voltage problem of the distribution network increasingly prominent.For effectively solving the low voltage problem of distribution networks,this paper studies the method of low voltage pre-judgment for users of distribution networks.The main work is given as follows:The user's low voltage influence factor was firstly analyzed.The impact of three aspects,i.e.,the low voltage power grid,10 kV lines and substations,on the user's low voltage was analyzed.And the determination logic of low voltage causes was proposed.Furthermore,the low voltage problem of the regional power grid in Weihai was analyzed and investigated.And finally,a system of low voltage influencing factors for the regional power grid in Weihai was established.For effectively solving the low voltage problem of distribution networks,a user's low voltage pre-judgment method based on typical transformer area was proposed.The essence of this method is utilizing less data to determine the low voltage range more accurately.Based on the proposed pre-judgment method,the relationship between the unbalanced branch current and the low voltage range was further analyzed,and a user's low-voltage fast pre-judgment method is offered,which realized a fast pre-judgment for low voltage by making a calculation query table of line voltage loss.For fixing the proposed user's low voltage pre-judgment method in the form of software,a voltage analysis auxiliary system and a voltage analysis and calculation tool,suitable for PC terminal and mobile terminal respectively,were developed.These two tools can greatly reduce the manual calculation burden of the method and improve the accuracy and practicality of the method.In combination with the graphical interface,the voltage of the transformer station is calculated.The main functions of the auxiliary analysis system,including graphic management,device mode diagram,user management,distributed new energy access,topology analysis,and power flow calculation,are introduced and explained.The operating environment of the voltage analysis and calculation tool is also analyzed quickly.The description of the work interface was provided.Finally,by studying the example of low voltage control in Shalongwang District of the regional power grid in Weihai,and the feasibility of using distributed photovoltaic power generation to solve the low voltage problem in Shalongwang District,the correctness and validity of the pre-judgment method and the practicality of the voltage computation assistant analysis system for distribution transformer areas were demonstrated.The user's low voltage pre-judgment method based on the typical transformer area studied in this paper provides theoretical guidance for the effective solutions of the user's low-voltage problem,and has a good engineering application prospect in the user's low-voltage governance of distribution networks.