The Research On The Problems Of The Distribution Automation

With the enlargement of distribution networks, automation reconstruction of it has become a trend. The state of distribution automation (DA) is summarized in this thesis. Based on this, model selection, layout and construction of DA is made under the condition of GuYuan district. The request and application of new technique in DA area is also discussed in this thesis, and corresponding conclusion is made. Main content and conclusion of this thesis are:(1). At present, the DA construction can implement some basic functions such as DA basic control and management. So the target and request of DA are very basic and a lot of advanced application can't be used, running of distribution networks still need the experience of management persons. Present techniques are in transition period and there must be a lot of new techniques in this period. Some good techniques and principles that can solve the request on site will be applied widely after the test of practice. Based on the present technique and request, distributed control system (DCS) whose functions are more scattered will improve the DA ability of urgent and special control. This is beneficial to construction of DA.(2). Based on the analysis of request of structure and running of distribution networks, the distributed model which utilizes single feeder as control object is selected as the best model of feeder automation (FA). Fault identification and isolation of feeder is accomplished by distribution terminal (DT) totally under such model, and distribution substation and main station keep the function of centralizedFA control as backup. This control model need change functions of present distribution terminal.(3). DT is the basic unit of information collection, calculation, transmission, control and protection. It is the object operated by DCS. All control of distribution networks relies on DTs. The concept of DT is extended in this thesis and all-in-one control node of DA (ACN) is presented. Any function such as control, measurement and calculation can be implemented by ACN. Hardware and software of ACN is designed based on this. Hardware of ACN adopts embedded DSP system based on double CPU structure, and software utilizes the real-time operating system. DT-OS software system is designed and improvement of ACN reliability is discussed.(4). Fault handling of FA is discussed based on the ACN. Quick feeder protection is presented utilizing two-dimensional node's control, and backup protection is discussed to ensure control reliability. Principle of longitudinal identification of single grounding fault is also discussed on DA platform.(5). Persons of management are offered a basic control platform by DA. The function of DA should be added continuously. The expert experience can be integrated in the advanced function of DA by combing universal control platform with ACN. This is special advanced application. Analysis and implement of special application is presented by the example of ice melting of GuYuan DA.