Explain why high gain controller would result in instability

-Explain why high gain controller would result in instability for the feedback system where the open loop transfer function has relative degree of 3 or more. (hint: use root locus method for discussion)

Solution

if the open loop gain has realtive degree 3 or more ie the order of the system also increases and if the order of the system increases poles also increases which are nothing but the internal capacitences and which may lead to positive feedback ... as at some frequency the capacitor may get shoted where input equals to output which leads to instability