Design And Application Of Some Novel Lag-Lead Compensators

In the control system, the phase-lag compensator can appreciable improve the steady state accuracy, but reduce bandwidth of the frequencies. The lead compensator can increase the bandwidth, enlarge stability margin of the system, enhance the transient response and improve vibration situation of the system. So, the lag-lead compensator was often adopted to improve comprehensively the system quality, such as rapidity, steady state accuracy and vibration. The traditional lag-lead compensator consisted of one pair real poles, and one pair real zeros,sometimes don't obtain the ideal calibration results. Therefore this thesis designed the double lag-lead compensator, composite lag-lead compensator and combination lag-lead compensator.In the chapter two of this thesis, we first designed a kind of double lag-lead compensator consisted of two pair of real zeros and two pair of real poles. Then based on the double lag-lead compensator, the composite lag-lead compensator was designed, which consists of two pairs of conjugate zeros and two pairs of conjugate poles. Meanwhile we illustrated the relations between zero and pole from the two kinds of compensator or the traditional lag-lead compensator. Argumentation by the pole-zero plots and Bode plots of the control theory, MATLAB simulation both indicated these two kinds of compensator have respective advantage to improve the system stability, enhance system antijamming ability Etc. compared with the traditional compensator. The composite lag-lead compensator also can provide a higher degree of freedom for the model design.In the chapter three of this thesis, we designed a kind of combination lag-lead compensator composed of a real zero, a real pole, a pair of conjugate zeros and a pairs of conjugate poles. Similarly, the theoretical arguments and the simulation experiment all indicated this combination lag-lead compensator not only obviously improves the model design degree of freedom, but also markedly improves the system rapidity and the steady state accuracy, enhances the system stability compared with the traditional compensator.