Improved relay auto tuning of P/PI controllers for unstable parallel cascade control systems
نویسنده
چکیده
This paper focuses on simultaneous relay auto tuning of open loop unstable parallel cascade systems. For stable parallel cascade systems,Vivek and Chidambaram[1] had discussed effect of higher order harmonics of symmetrical relay output, which accounts for error in ultimate controller gain estimation. In the present work, this method is extended to parallel cascade controllers for open loop unstable systems. Using improved ultimate controller gains, the conventional relay autotuning method is compared with proposed method for the conventional cascade control configuration (P/PI). The controllers are designed using Zeigler Nichols tuning rules based on the improved ultimate gain.
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