Which controller type is best suited when control loop responses must eliminate both offset and oscillation_________________?
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Answer: D. Proportional integral-derivative (PID) controller
Explanation
PID controllers combine proportional, integral, and derivative modes to eliminate steady state offset and damp oscillations. Integral action accumulates past errors to drive steady state offset completely down to zero. Derivative action anticipates future error trends to suppress overshoot and stabilize closed loop oscillations. Proportional controllers alone always leave a persistent steady state offset following a step load change. Derivative control responds to the rate of change of error, improving damping and transient stability. Combining all three control modes creates a versatile algorithm capable of meeting rigorous industrial specifications.
Chemical plant automation relies heavily on PID controllers to maintain precise temperature and pressure setpoints. Eliminating offset while preventing aggressive oscillations ensures high product purity and equipment longevity. Modern distributed control systems utilize advanced PID tuning algorithms to optimize complex industrial loops. Proportional controllers cannot eliminate steady state offset without manual reset adjustments by operators. Proportional derivative controllers improve transient stability but still suffer from uncorrected steady state offset. Proportional integral controllers eliminate offset but lack derivative action to damp severe process oscillations.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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