【正文】 ruction requirement and the effect on construction.) Task and scale of project The location is ideal for PV power plant because of the rich solar resource, convenient transport and grid connection condition. Samoa’s 5MW ongrid PV demonstration project will adhere to the principle of world sustainable development of energy, in line with the national energy strategy which calls for reducing consumption of fossil resources and harmful emissions such as coalfired pollution. So this project will play an important role in promoting the local tourism and local economic development. Therefore, the development of this project is vital necessary. Project design This project uses distributed generation and centralized grid connection strategy. The whole system will be divided into five 1MW units and connects to local grid at 22kV voltage point through five monocrystalline PV panels, the actual output . For each 1MW subsystem, there are four 250kW gridtie inverters. Each 250kW inverter consists of one DC power distribution unit, in which there is 10 DC biner box with lightning protection, 6 inputs for each biner box and total 56 inputs for 1MW unit. For each input, there is one PV string with 16 panels in series. So 1 250kW inverter has 896 PV panels input, and 3584 PV panels input for 4 inverters. At the output of each inverter, there is an AC power distribution cabi with lighting protection, and connecting to a 1250kVA Technical design Main power system design Silicon PV module is CEEG SST28072P, monocrystalline, the standard power of 280W, the peak voltage of . Gridtie inverter is SG250KTL, maximum power tracking voltage range DC450V ~ 880V, output power 250kW, the output voltage 270V, Europe efficiency %, total 20 gridtie inverters for PV power system. Feasibility Research Report China Electric Equipment Group Five point, 5 input and 1 output, then to local 22kV class grid. Central control system design The department of electric power in Samoa will take charge of the project and take fewpeople attended method. Telecontrol workstation will be used in the control room for information transmission to and monitoring from dispatching department. The automation system achieves 22kV line, the main transformers, the centralized monitoring and dispatching department telecontrol monitoring of AC switch cabi. 20 gridtie inverters will be applied in the project. The monitoring and protection of each inverter is achieved by its inner detecting system and protection device. 1 set of environmental monitoring system is equipped to monitor the environment conditions. Power measurement of the PV power station will be at the interface point to the grid. Communication The munication of Samoa’s 5MW ongrid PV power project includes system munication, administration munication and inner station dispatch munication. Construction The total capacity of the project is with 17920 280W solar modules, 1120 supports of fixed installation style, five 1250KVA transformers and interface to grid through 22KV class power line. Civil engineering of the PV power station includes base of PV modules, five AC and DC power distribution rooms, prehensive building, prehensive pumping station, sandproof wall, inside road, etc. According to Code for Seismic Design of Buildings (GB 500112021） , the Comprehensive Building, ACDC power distribution room, and prehensive pumping rooms belong to C categories, seismic intensity of 7 degrees, the basic design of the ground acceleration value of . According to site conditions, solar module follows the basis of 50m / s design. Single array takes concrete reinforcement and grade of C25. The base is higher than site average, the depth , and the concrete pouring of one point is . The PV power station in the windy area, the bination of engineering and biological means will be adopted for wind proof at this stage. That is, building height wall around the PV power station and planting poplar outside of the wall. What’s more, PV modules, supports and bases are sandproof designed. Fire protection A. PV power station is not equipped with firefighting anization, but a parttime firefighter should be employed. At initial stage, fire will be handled by personnel from the internal station, and meanwhile with notification of the local fire brigade to fight against fires。 Feasibility Research Report China Electric Equipment Group B. The fire engineering design of the project adopts the integrated fire technical measures include the fire prevention, monitoring, alarm, control, fire fighting, smoke exhaustion, and escape. The aim is to reduce the possibility of fire. Once happens, it can be extinguished in a short time and the loss can be reduced to a minimum, while ensuring the safety of fire evacuation。 B. Close to the main power grid reducing new transmission lines investment。s1 Temperature range – 40 176。 Monitor and control room: 80m 20m 10 = 1600 m2。 Cathode and Anode with dedicated Highvoltage lightning protection devices。 The voltage value of fuse is not less than DC1000V。4480≈56, and 224 strings in parallel for 1MW PV system. So 1MW unit needs 3584 PV modules and the power is . For 5MW system, it needs 53584=17920 280Wtype PV panels, 16 in series for one string, 1120 strings in parallel for whole system, and the power can reach . Layout of PV array Distance design In order to avoid shading between arrays, distance in front and behind contiguous PV modules should be not less than D: D = 〔 arc sin ()〕 Where Φ is the local geographical latitude (positive in the northern hemisphere, southern hemisphere