西安理工大学自动化与信息工程学院自动控制理论Chapter6 The Compensation of the Linear Control Systems.pptVIP

Chap 6 The Compensation of the linear control systems Chap 6 The Compensation of the linear control systems Definition of the compensation: Compensator: The compensator is an additional component or circuit that is inserted into a control system to compensate for a deficient performance. 6.2.3 Comparing active compensation controllers and passive compensation controllers 6.3.2 Phase-lag compensation using the root locus (P577) 6.3.2 Phase-lag compensation using the root locus (P577) 6.4.2 Phase-Lag Compensation using Bode diagram 6.4.4 Compensation according to the desired frequency response 6.2 Operation analysis of the basic compensators 6.3 Cascade compensation by Root loci method 6.3.1 Phase-lead compensation (P569) Example 6.3.1: The root loci of the system shown in Fig.6.3.1 Fig.6.3.1 solution Analysis: unstable. phase-lead compensation 6.3 Cascade compensation by Root loci method Fig.6.3.2 6.3 Cascade compensation by Root loci method Fig.6.3.3 There are two approaches to determine zc and pc . (1) Maximum α method (2) Method based on the open-loop gain 6.3 Cascade compensation by Root loci method For this example we choose the Maximum α method: Fig.6.3.3 In terms of the sine’s law: Root locus of the compensted system 6.3 Cascade compensation by Root loci method The root locus of the compensated system is shown in Fig.6.3.4 Fig.6.3.4 Steps of the cascade phase-lead Compensation: (1) Determine the dominant roots based on the performance specifications of the system: (2) plot the root locus of the system and analyze what compensation device should be applied. 6.3 Cascade compensation by Root loci method (3) Determine the angle φc to be compensated: (4) calculate θ andγ: (6) plot the root locus of the compensated system and make validity check. (5) calculate zc and pc In terms of the sine’s law : Example 6.3.2: Solution: The root locus of the system is shown in Fig.6.3.5. -10 Fig.6.3.5 6.3.2 Phase