Study On The Structure Of Urban Low Voltage DC Power Distribution Network

The development of social economy, city of industry and agriculture, electricity consumption rise, new electrical equipment and new energy network, making the structure of grid current increasingly large and complex power system, load control has become more sophisticated. The disadvantages of the traditional AC power distribution network is becoming more and more obvious:the local load intensive electricity led to the substantial increase in the traditional AC power distribution network transmission the channel capacity margin decrease, the transmission pressure, the traditional AC transmission channel can not meet the load demand, restricted by geographical conditions, the transmission line expansion does not solve the problem of all channel pressure; new type DC electrical equipment due to extensive use of AC/DC converter and other equipment, two times the cost of the power grid increased greatly, also makes the operation power grid is more complex; scenery and other new energy grid to grid structure and expansion, the new energy wave The dynamic and intermittent nature of the traditional AC power grid stability has brought a huge impact.In this paper, we first introduce the DC power distribution network, a series of key technical problems, discusses the DC distribution system grounding, the protection technology of the DC distribution system were in-depth analysis, summed up the current DC distribution system protection configuration is facing a series of bottleneck problem, from system network loss and voltage drop are two aspects of the influence brought by the distributed energy grid of DC power distribution system.Secondly on DC distribution voltage grade evaluation method research, from three angles of economy, reliability and adaptability of evaluation index of detailed analysis, given the evaluation steps and methods, expounds the principles of voltage grade comprehensive evaluation system.Finally, from two aspects of transmission capacity and economy, the results show that the transmission capability and economic performance of DC power distribution network are better than that of AC power distribution system.