Question

The following block diagram represents a cascade control system for a temperature furnace. H_{v}=1, G_{p}=\frac{1}{(s+2)}, H_{p}=\frac{1}{(s+1)}, T 1=1, T 2=1, H_{c}=1 What is the main advantage in using cascade control?

Describe the dynamic behaviourof the inner and outer loops. Y2and the time constant of the inner loop. What canYsp2Calculate the transfer functionyou say about the stability of this inner loop? Redraw the block diagram by replacing the inner loop by its transfer function and findY1the transfer function of the outer loopYsp1" Using a proportional controller in the primary loop (Gc = Ke) find the characteristic equation of the cascade system. Find the values of Ke for which the cascade system is stable.

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