外文翻譯--三相電壓型pwm整流器建模和仿真研究-閱讀頁
2024-09-10 17:13本頁面
【正文】 litudes of two signals are the same and opposite to the sign of another signal. And no sign change occurs during each interval. The value of N in every sector is interval 1,for example,B0 is positive,B1 and B2 are negative. Six intervals of B0 B1 and B2The sector in which is depends on the expression (6) Compared with ,it is obvious that the corresponding relations between value N and sector are seen in Table1. Table 1 Determination of sector of based on NThreephase voltage can be treated as a voltage vector Vs. There are many different methods of modulation to synthesize according to the different binations eight vectors. Among these methods,the twophase modulation can make switching loss minimize,in which one switch should be always set ON or OFF in one working desired reference vector is sampled in every subcycle Ts and realized by time averaging the three nearest space vectors in the space vector plane. For example the reference vector shown in magnitude Vs and angleθin sectorⅠis realized by applying the active vector 1the active vector 2 and the zero vectors. The durationsT1,T2 and TZ of the three space vectors respectively is calculated as:The vector synthetic method of other sector is similar. The expressions which is developed on the universal variable X,Y,Z are shown as following: For any reference vector the duration time of two space vectors are assigned as Table2.3 Simulation ResultsBased on the former analysis the MATLAB/SIMULINK simulation model for the VSR of the test load was implemented using IGBT modules and following values:uRMS≈220V,L ≈3mH,R≈,C ≈4700Mf,RL≈16Ω,vdc=700V.The following two figures summarize the results of the shows the transient response of the output voltage. The second figure shows transient response of input current. In this simulation at start time the dc bus voltage rests at the diode rectifier level with a resistive load of RL=,the control action is applied keeping the load resistance and the output voltage increases to the desired dc shows the voltage and current on line side. We can see the current of sinusoidal wave is the same phase with the voltage. Simulation result for DCLink voltage dynamics4 conclusion In this paper a no linear transformation is used to derive for threephase new control strategy using inner current loop with state feedback decoupling and outer voltage square loop based on the space vector modulation is introduced in this using nonlinear input transformation the conventional nonlinear models can be improved to linear models. This improvement makes the design of the controller bee straightforward. A novel SVPWM algorithm has been described and results shown it has advantages of better controlling precision fewer switching motions simpler calculation easier realization with microputer higher utilization of DC voltage. Simulation result for voltage and current waveform of phase A
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