Variable speed drive control for heat pump system

• Main Author: Fang, Zhenghua
• Other Authors: Wang Youyi
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/71672
• Institution: Nanyang Technological University

Superheat control play a primary role in refrigeration and air conditioning systems. Good superheat regulation able to optimizing system efficiency and prevent the component from damaging. However, it is a challenging problem to control superheat due to the lack of understanding towards components parameters. This report reveals independent control method for heat pump system by using Proportional-Integral-Derivatives(PID) controller to control superheat. In heat pump system, there are two variables to be controlled. Decoupling model was used to eliminate the interfering loops between these two variables so that the PID controller can be designed individually. The two controlled variables are Superheat and heater tank temperature which are respectively control by Electric Expansion Valve(EEV) and compressor frequency to save energy and enhance system performance. For a respectively controlled variable to meet the set point, empirical data is collected from the experiments and analyze to obtain First Order Plus Time Delay(FOPTD) transfer function. PID Controller for the variable then can be design based on FOPTD.