Research On Sower Supply Technology And Automatic Grid Connected System Of Ship Shore Power

In recent years,with the recovery of the world economy and the rapid development of economy in our country,shipping trade showed vigorous development trend.Our country’s port cargo throughput is leading position in the world.During the ship in the port fuel generator must keep in power supply to guarantee the normal work of the ship power equipment.But the ship fuel utilization rate is low,the loss is serious,at the same time excess electricity produced cannot be stored,causing huge waste.And it causes great pollution to the port city’s environment.Ship port shore power technology makes the ship.get power during the ship in the port.So the ship can shut down their own generators,which can effectively solve the port Marine environment pollution and noise pollution.Ship shore power technology is still in the pilot stage in China.The ship shore power system is limited in our country on the electric power system of ship,shore power supply capacity of small power switch wiring cumbersome,slow speed,this paper has done the following research:First,under the guidance of the principle of miniaturization design,a centralized high voltage power supply system is designed.The designed power supply system has the characteristics of small space requirement,high integration,low cost and good stability.It solves the problem of insufficient capacity,low efficiency and large space demand of traditional shore power supply.Second,aiming at the problem that the traditional ship shore power supply can only provide 50Hz AC power,the capacity is not enough,this paper puts forward the power supply system and carrier phase shift modulation strategy of Cascaded Multilevel Inverter Based on H bridge.It solves the problems of low output voltage,small capacity and low harmonic performance.The use of Matlab2013a/Simulink software,SPWM modulation strategy on the phase shift of H bridge cascaded inverter and carrier of the simulation software.Through the harmonic analysis of the output voltage,we prove the rationality and feasibility of the carrier phase shift strategy and the H bridge cascaded inverter is applied to ship shore power system.Sum up the carrier phase shift strategy and cascade combined with the use of inverter principle and matters needing attention.Third,aiming at the problem that the power consumption of the ship shore is longer and the power is needed to be cut off,a new method based on discrete Fourier transform is proposed.By means of the parameter measurement method of discrete Fourier transform,the necessary parameters such as the phase angle and frequency of the power supply are measured,and the t_q1 is captured.Fourth,according to the particularity and the function requirements of the ship shore power system,ship shore power grid automatic system software design and hardware design.The hardware part includes AC converter circuit,phase discrimination circuit,frequency measurement circuit,phase measuring circuit etc.Finally,based on the H bridge cascaded high voltage inverter to design the software of the ship shore power supply system,realize the ship shore power system high voltage and power supply and 50Hz/60Hz dual frequency power supply which can satisfy all requirements of power supply by the Hong Kong ship.