The Reaserch Of Stability Of Diesel Generator Sets And Reactive Power Compensation

As important backup power,emergency power and mobile power,diesel generator set is widely used in important institutions such as communications,hospitals,financial institutions,and where municipal supply network is difficult to cover.In the diesel generator set,the stability of the engine speed determines the stability of the generator sets output power directly,in addition,in the micro-grid which is composed of off-grid diesel power system and its loads,there will be a lot of inductive loads,they will consume the reactive power,which will reduce the generator’s power quality.In this paper,in order to increase the output power quality of the diesel generator set,traditional diesel generator set is improved and enhanced,so it makes them have good speed regulation and reactive power compensation.Firstly,the study of the situation and control strategies about the diesel generator speed control system and the reactive power compensation system are completed,and the structure of the entire system is made,including speed control system,reactive power compensation system and the entire crew’s monitoring system.Based on the analysis of the Diesel Engine Speed principle,we establish the mathematical model of WD615 diesel engine and G2-type fuel injector.Next,the basic principle of TSC reactive power compensation device is studied,and we design the reactive power compensation’s scheme.Thyristor zero trigger method is used as TSC switching time,the connection mode of compensation capacitors is star-model structure,and grouped by 8: 4: 2: 1 ranging content,the calculation method of compensation capacity of the capacitor is determined.The complex control of power factor and reactive power is used as the control strategy,it lays a theoretical foundation for the design of hardware and software.Secondly,This paper determines the overall structure of the diesel generator set.Because the mathematical model of the controlled is nonlinear and time varying,on the basis of analyzing the principle of conventional PID algorithm and fuzzy control,this paper proposes fuzzy PID control method.Using MATLAB simulation,it compares the control effect of the conventional PID control algorithm with the Fuzzy PID control algorithm which is used in this paper.The result shows that,the Fuzzy PID control algorithm is feasible and has better control effect on the engine speed control.Then,this paper designs the hardware of the speed control system and reactive power compensation system of the diesel generator set,using STM32F107VCT6 chip as its control core.it also designs the drive circuit of injector and the signal acquisition and processing circuits of diesel engine ’s speed,temperature and pressure,and designs the main circuit,the control circuit and the switching control circuit of reactive power compensation device,and the control circuit includes the acquisition circuits of voltage and current,the circuit of signal pre-processing,the circuit of zero-crossing detection,the circuit of power factor measurement,and the function circuits of peripheral function of STM32.Finally,this page designs the software procedure of diesel generator set.It includes the diesel engine rotating speed control program,basic function module of STM32,the generator-side data collection and calculation,power factor measurement,capacitor switching and other programming designs.In addition,this page designs the monitoring system of the upper computer in MCGS configuration software,it makes the system have a good man-machine interface,and it can be used for system configuration,performance monitoring and data management and so on.