The Research Of Intelligent Protection For Distribution Network Based On Multi-Voltage Grade Zone Information

With the rapid development of economy in our country,the demand for electricity is growing in all walks of life,people will become more and more high to the requirement of power grid security and stability.Is complex in guangdong power grid has formed the operation of ac/dc hybrid power grid,in order to ensure the safe and stable operation of main and provids the power grid voltage level(110 kv and below)of relay protection strict constraints was proposed,and the shortage of line corridors resources,the influence of such factors as the structure of the grid layout,operation arrangement severely restrict,coupled with the continuously distributed power access,has brought the traditional relay protection and safety automatic device test.Current distribution network system is generally used distance protection or over-current protection as main protection circuit,with the growing sophistication of grid structure and operation mode by only single terminals have already can’t satisfy the demand of the power grid operation,the protection of the differential protection based on region information demand becomes increasingly urgent.The area of lines in the area of the differential protection as the main protection,can complete all quick,greatly improve the fault clearance time,the stable running of the system,also solved the protection setting value step by step with the contradiction of selectivity and quick action.For regional power grid,it is necessary to develop a new set of self-healing protection control system to realize regional power grid,failure occurs when the power grid,through real-time information receiving area,comprehensive logical judgment,determine the fault location,fault isolation scheme,quickly closed the stand-by power switch,the area was restored to power grid can rapidly and accurately.Thispaper will study line protection,main transformer protection,bus protection,prepared from the cast,stability control function integration within the unified network intelligent protection and control system,through internal high-speed data bus to exchange information between different modules,coordination between different functions can be action,when a fault occurs,can quickly locate and remove the fault,through the main and standby power supply recovery and electrical contact,and removal of part load according to the load overload situation,to ensure the reliability of power supply,solve the traditional power system protection,Ann control and emergency control system are independent of each other,with difficult problems between different function,greatly improve the safety of the local power grid operation stability and reliability of power supply.In this paper,the system is based on the regional power grid of Guangdong Power Grid,and the RTDS test platform is built.The simulation results show that the control scheme is correct and the level of intelligent protection is greatly improved.