Wu Zhengrong

Analysis of overvoltage caused by intermittent earth fault and its suppression method

Intermittent earth faults occur frequently in urban distribution networks, causing overvoltage in the whole system. This paper first presents the distribution characteristics of transient overvoltage caused by intermittent earth faults. Overvoltage level at the end of a sound line turns to be higher than that of the faulted line. In resonant grounding system with Petersen coil based on thyristor controlled reactor (TCR), overvoltage appears to be more severe due to response delay of compensation. Therefore, the influence on overvoltage level of Petersen coil compensation is analyzed, based on which, an overvoltage suppression method is proposed.

Distribution network expansion planning considering comprehensive equipment utilization

An equipment comprehensive utilization index considering power system security and operating mode was provided, and a distribution system expansion planning method based on this index was proposed. The expansion planning method takes “effective use of existing and additional equipment resources” as the guiding ideology, and makes full use of the historical operation data to realize the distribution system expansion planning. The planning model and the solving process using improved particle swarm algorithm are provided in the paper. An actual case study is used to verify the effectiveness of the method.

Discussion on the technical architecture of smart grid in Hainan

Smart grid demonstration projects are being carried out all over the world, but none of them involves integrated demonstration of large island-based power grid. This paper analyzes the demand for smart grid in Hainan, proposes a 4-layer technical architecture including generation, transmission, distribution, and consumption. On this basis, the core business of the overall technical architecture is discussed, which include intermittent energy consumption and smart disaster early warning. Then the structure and functions of the support system are introduced. Finally, the key technologies and development trends are discussed.

Integrated Technical Planning for Regional Smart Grid

The regional smart grid demonstration project in Hainan is a comprehensive integration demonstration project involving the whole Hainan power grid. Based on smart grid construction need analysis, this paper proposes a comprehensive integrated technology framework which includes generation, transmission, transformation, distribution and charging technology of electric vehicle. Then, the content of the demonstration project is introduced later, which includes smart dispatch, smart disaster early warning systems, operation and control of smart distribution, operation and energy management of micro grid, electric vehicles. In the end, the significance of the demonstration is discussed.