What is a Proportional Controller?

Encyclopedia
09/19/2024


What is a Proportional Controller?


Proportional controller is one of the most basic control algorithms in automatic control systems, usually represented by the letter "P". The proportional controller controls the response of the system by adjusting the output signal to be proportional to the error signal.


Basic principle


The basic idea of the proportional controller is to reduce the system error by adjusting the output signal of the controller. Error is the difference between the expected value and the actual measurement.


6816e2bbfd691ecc120fe261ca916af7.jpeg


u(t) is the output signal of the controller.


Kp is Proportional Gain, which determines the magnification of the output signal to the error.


e(t) is the error signal, defined as e(t)=r(t)−y(t), where r(t) is the set value and y(t) is the actual measured value.


Advantage


  • Fast response: The proportional controller can quickly respond to changes in error.



  • Simple: simple structure, easy to understand and implement.



  • Flexibility: The response speed of the system can be flexibly adjusted by adjusting the proportional gain.



Shortcoming


  • Steady state error: Since the proportional controller only considers the current error, the system may have a certain steady state error.



  • Overshoot: If the proportional gain is not selected properly, it may cause the system to overshoot, that is, the output value oscillates near the set value.



  • Stability problems: Excessive proportional gain may cause system instability.



Apply


  • Temperature control system: Maintain the set temperature by adjusting the power of the heater.



  • Flow control system: Control the flow of fluid by adjusting the opening of the valve.



  • Pressure control system: Maintain the pressure in the pipeline by adjusting the output of the pump.


  • Motor control system: By adjusting the speed of the motor to achieve the required output power.


Encyclopedia

The Electricity Encyclopedia is dedicated to accelerating the dissemination and application of electricity knowledge and adding impetus to the development and innovation of the electricity industry.

What is Automatic Voltage Regulator?
What is Automatic Voltage Regulator?
An automatic voltage regulator is employed to regulate voltage, converting fluctuating voltages into a constant one. Voltage fluctuations mainly stem from variations in the load on the supply system. Such voltage variations can damage the equipment within the power system. These fluctuations can be mitigated by installing voltage - control equipment at various locations, such as near transformers, generators, and feeders. Multiple voltage regulators are often placed throughout the power system t
Edwiin
05/22/2025
What is Static Voltage Regulator?
What is Static Voltage Regulator?
Types of Static Voltage RegulatorThe static voltage regulator is superior to electromechanical regulators in respect of the accuracy of control, response, reliability and maintenance. The static voltage regulator is mainly classified into two types. They are;Servo Type Voltage RegulatorMagnetic Amplifier RegulatorThe types of static voltage regulator are described below in details;Servo Type Voltage RegulatorThe main feature of the servo type voltage regulator is the use of the amplidyne. The am
Edwiin
05/21/2025
What is Arc Extinction Circuit Breaker?
What is Arc Extinction Circuit Breaker?
When the current-carrying contacts of a circuit breaker separate, an arc forms and persists briefly after contact separation. This arc is hazardous due to the heat energy it generates, which can produce explosive forces.A circuit breaker must extinguish the arc without damaging equipment or endangering personnel. The arc significantly influences the breaker’s performance. Interrupting aDC arcis inherently more challenging than anAC arc. In an AC arc, the current naturally reaches zero duri
Edwiin
05/20/2025
Air Break Circuit Breaker
Air Break Circuit Breaker
In an air break circuit breaker, the arc is initiated and extinguished in substantially static air as the arc moves. These breakers are used for low voltages, generally up to 15 kV, with rupturing capacities of 500 MVA. As an arc-quenching medium, air circuit breakers offer several advantages over oil, including:Elimination of risks and maintenance associated with oil use.Absence of mechanical stress caused by gas pressure and oil movement.Elimination of costs from regular oil replacement due to
Edwiin
05/20/2025
Inquiry
Download
IEE-Business is dedicated to serving the personnel in the global power industry.
Join IEE-Business, not only can you discover power equipment and power knowledge, but also canhnd like - minded friends!