AME 11 End of Unit – SVE Study

AME 11 End of Unit Quiz

1 / 12

Define the term Proportional Action.

B) Proportional action integrates the error over time to adjust the control output, aiming to eliminate steady-state error.

C) Proportional action predicts future errors by adjusting the control output based on the rate of change of the error.

D) Proportional action uses a fixed output level regardless of the error magnitude to maintain system stability.

A) Proportional action adjusts the control output based on the magnitude of the error, where the output is directly proportional to the difference between the setpoint and the actual value.

2 / 12

What is the relationship between proportional band and gain in a control system?

B) Proportional band is inversely proportional to gain.

A) Proportional band is directly proportional to gain.

D) Proportional band and gain are the same thing.

C) Proportional band and gain are independent of each other.

3 / 12

Describe the reasons for integrating the error signal and the effect it has on the governor fuel rack.

C) Integrating the error signal helps in reducing the proportional gain needed for control, which simplifies the control system and makes the governor fuel rack less responsive to changes in engine speed.

D) Integrating the error signal helps in stabilizing the system by making the governor fuel rack adjustments slower, which prevents any rapid changes and ensures the engine speed remains constant.

B) Integrating the error signal helps in amplifying transient responses by applying a large correction immediately, causing abrupt changes to the governor fuel rack and quickly adjusting the engine speed.

A) Integrating the error signal helps in eliminating steady-state error by providing continuous correction over time, leading to a gradual adjustment of the governor fuel rack to maintain the desired engine speed.

4 / 12

With reference to engine governors, explain hunting.

A) Hunting is the term used to describe a governor's inability to maintain a constant engine speed due to excessive fluctuation in engine speed around a set point. Reason: Hunting occurs when the governor repeatedly overshoots and undershoots the target speed, causing erratic engine performance.

B) Hunting refers to the governor’s ability to detect and compensate for sudden changes in load quickly. Reason: Quick load compensation is not referred to as hunting but rather as a desirable feature in governors.

C) Hunting describes the process of adjusting the governor's sensitivity to improve engine speed stability. Reason: Adjusting sensitivity is related to tuning, not hunting, which involves excessive fluctuation in engine speed.

D) Hunting is the term used for a governor’s ability to remain unaffected by variations in fuel quality. Reason: Fuel quality variations impact engine performance but are not described as hunting.

5 / 12

State with reasons, the type of actuator fitted to the process valves for a lubrication oil cooling system in which the valve diverts the oil through a cooler.

A) Electric Actuator: Reason: An electric actuator offers precise control of the valve position and can be easily integrated with control systems to modulate the oil flow through the cooler as required.

C) Hydraulic Actuator: Reason: Hydraulic actuators are generally used for high-force applications and may be less suitable for the precise control required in diverting oil through a cooler.

D) Manual Actuator: Reason: Manual actuators require manual intervention to adjust the valve position, which is not ideal for automatic and precise control of oil flow through a cooler.

B) Pneumatic Actuator: Reason: Pneumatic actuators provide reliable and fast operation and are well-suited for applications requiring frequent adjustments to the valve position, such as diverting oil flow through a cooler.

6 / 12

Describe using control block diagram terms how a governor maintains the speed of a diesel engine driving a generator.

B) The governor compares the actual engine speed to the desired speed setpoint and uses a proportional-integral-derivative (PID) control block to adjust the fuel input and maintain the engine speed.

C) The governor uses a manual control block to adjust the engine speed directly without feedback, ensuring the engine speed remains constant regardless of load changes.

A) The governor adjusts the fuel input based on the difference between the desired speed setpoint and the actual engine speed (feedback), using a proportional-only control block.

D) The governor uses a feedback loop where the actual engine speed is compared to a fixed reference value, adjusting the fuel input based on a simple on-off control block.

7 / 12

Explain the purpose of Derivative Action.

A) Derivative Action aims to eliminate steady-state errors by continuously adjusting the control output based on the accumulated error over time.

D) Derivative Action compensates for errors in the system by applying a proportional correction based on the current error value alone.

B) Derivative Action helps to anticipate future errors by reacting to the rate of change of the error, thereby improving the system’s stability and response time.

C) Derivative Action adjusts the control output to maintain a constant error, ensuring that the system remains at a fixed setpoint without any fluctuations.

8 / 12

Describe the effect of excessive Derivative Action.

C) Excessive Derivative Action can result in a system that quickly reaches the setpoint without overshooting or oscillating.

A) Excessive Derivative Action can lead to a sluggish response time and an increase in steady-state errors.

B) Excessive Derivative Action can cause the system to become overly sensitive to noise, leading to oscillations and instability.

D) Excessive Derivative Action can decrease the system’s overall response time and improve its accuracy in maintaining the setpoint.

9 / 12

With reference to hydraulic governors fitted to alternators designed to run in parallel, explain why these governors have adjustable integral action.

C) To increase the governor’s sensitivity to small changes in load, which improves the alternator’s synchronization with other units.

D) To prevent the governor from responding to minor fluctuations in the load, reducing wear and tear on the governor mechanism.

B) To ensure that the governor can handle variations in load and maintain stable operation by adjusting the steady-state accuracy.

A) To allow the governor to respond more quickly to sudden load changes and reduce the frequency of the alternator.

10 / 12

Describe integral action in a control system.

C) Integral action maintains a constant control output regardless of changes in the error signal.

D) Integral action adjusts the control output to match the process variable to the setpoint instantly.

A) Integral action adjusts the control output based on the rate of change of the error signal.

B) Integral action increases the control output to eliminate steady-state error over time by integrating the error signal.

11 / 12

With reference to engine governors, explain sensitivity.

D) Sensitivity indicates the level of noise produced by the governor during operation. Reason: Noise levels are not related to the sensitivity of a governor but rather to its design and operation characteristics.

C) Sensitivity describes how easily the governor can detect changes in ambient temperature and adjust engine speed accordingly. Reason: While temperature changes can affect engine performance, sensitivity in a governor is primarily related to its response to load changes and fuel adjustments.

B) Sensitivity refers to the governor’s response to small changes in the fuel supply, affecting the engine speed control. Reason: A sensitive governor will react quickly to minor adjustments in fuel input, thereby maintaining precise engine speed control.

A) Sensitivity refers to the governor's ability to maintain engine speed despite fluctuations in load conditions. Reason: A sensitive governor adjusts engine fuel input or throttle position to counteract variations in load and keep the engine speed constant.

12 / 12

State the reasons for fitting a pneumatic process valve with a volume booster.

A) A volume booster is fitted to increase the flow rate of air to the actuator, enabling faster valve movement and reducing the time required to achieve the desired valve position.

B) A volume booster is fitted to reduce the air pressure supplied to the actuator, which helps in minimizing the force required to operate the valve.

C) A volume booster is fitted to decrease the overall air consumption of the valve, thereby improving energy efficiency in the pneumatic system.

D) A volume booster is fitted to provide redundant control signals to the actuator, ensuring higher reliability in case of signal loss.

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