Study On Parallel Operation Control And Stability Of Warship Double Electrical Power System

With the application of electric propulsion devices and high energy weapons in warships,the demand for electricity in warships is increasing.At present,China's plans for power system in small warships usually use double power stations as alternatives.Since the span cable between the two power stations is relatively long,the voltage droop caused by the cable may affect the stability of parallel operation of double power stations,and the power quality of the remote load.In view of the long-span cable's impact on the operational stability of the double power station in warships,so far no scholars have conducted a special study.Based on the military project of 708 research institute,this paper studies a certain type of warship with double power stations using parallel operation control principle of generators.According to the network operating structure under typical operating conditions,the study on the effects of the long-span cable on the operational stability of the system is carried out,exploring possible problems and studying the corresponding control strategy to improve the system stability.The main work is as follows:1.Based on the composition of the warship's diesel generator set,analyzing the mathematical model of each module,setting up the simulation model in the PSCAD simulation software,and then verifying the correctness of the model according to relevant indicators;Based on the single-machine simulation model,setting up the parallel operation simulation model according to the speed regulation and voltage regulation characteristics of the generator set,and then studying the stability of the process of parallel operation.2.Based on the single line chart and load tables of the warship's power system,setting up the simulation model of the power system with double power stations.Analyzing the influence of long-span cable on the parallel operation stability of the warship's double power stations under typical operating conditions,typical operating conditions switching,and short-circuit faults in the long-span cable,to provide the basis for the design of the power station control device.3.Applying the droop control strategy to the parallel control of the warship's double power stations,and then improving the traditional droop control by combining the characteristics of the warship's double power stations.On the basis of the improved droop control,the voltage level of the system can be adjusted automatically by adapting the reactive power-voltage sag coefficient.Compared with the current methods of reactive power distribution,the advantage of this control strategy is verified by simulation analysis.The simulation results are as follows: The simulation model established in this paper can run stably and the indicators meet the industry standard.The long-span cable can lead to uneven distribution of reactive power in generators of different power stations.When the input position of the generator and the load are different,the long-span cable will also has different effects on the reactive power of generators in different power stations.When the running generators are in the same power station,the short-circuit fault of the long-span cable will cause the non-fault area losing energy,extending the power outage scope.The improved droop control strategy proposed in this paper can improve the accuracy of reactive power distribution and ensure that the system voltage level is not affected by load changes.