energy-saving inverter controlled induction motor powered a number of technical studies

Title: energy-saving inverter controlled induction motor powered a number of technical studies
Author: Wang Ai-Yuan
Degree-granting units: East China University of Technology
Keywords: induction motor;; efficiency optimization;; energy-saving operation;; Frequency;; core loss
Abstract:
Frequency control of induction motor with the fan and pump loads of speed control and production process, the need for servo control developed, the existing widely used construction induction motor with frequency control algorithm is simple, the dynamic characteristics of a good advantages, but take into account the motor running and efficient light-load operation. With the global environmental protection and energy shortages become more prominent, people began to pay more attention to energy issues. Induction motor as the main electrical equipment, its energy research has Neodymium Magnet important practical significance. In this context, this paper carried out the induction motor drive energy-efficient power control and related technology research, to solve the motor problem of low efficiency at light loads.
By analyzing the mathematical model of induction motor speed control and four basic techniques that voltage - frequency coordination and control, slip frequency control, vector control and direct torque control, that these methods cause the motor to control the light-load efficiency of running down the reasons for iron loss is ignored, and the rated constant flux control. Based on this proposed induction motor considering iron loss of vector control system, by controlling the air-gap torque current component and the excitation component to achieve torque and flux vector control solution even, and thus indirectly control the stator currents, studies have shown that system dynamic performance has been significantly improved.
For speed control and energy control at the required time-varying parameters, non-linear characteristics, the paper two types of induction motor parameter identification method for both identification and off-line identification has been studied, proposed to consider the iron loss from line rotor resistance identification and correction of online self-identification method.
This speed controller for three studies: First, the conventional PI speed controller has been improved by the operating conditions selected adjustable parameters to improve the static and dynamic performance; Second is the sliding mode control, neural network controller according to their operating characteristics to improve the design, sliding mode controller with nonlinear sliding http://www.everbeenmagnet.com/ surface smooth continuous function to replace the sign function to eliminate high-frequency jitter, the weights of neural network controller with adaptive capacity; third is to propose a kinds of induction motors based on disturbance observer and control of slip frequency interference control, the disturbance observer tracking differentiator using a variety of load disturbances observed, and then slip frequency control according to the principle of compensation for disturbance torque can be effectively solve the induction motor slip frequency control in poor dynamic response, control of low precision.
Induction motor drive power saving operation control is the focus of this study, through the motor system loss analysis and efficiency analysis to determine the efficiency of the motor system optimization in the direction of energy to run the motor body, and mainly for small and medium sized motors energy-saving operation control, efficiency optimization by adjusting the stator supply voltage, frequency, voltage or frequency than the excitation flux to achieve, and thus draw the following energy-saving induction motor control in several ways:
(1) According to the induction motor steady-state model proposed a scalar control of energy to run programs, which according to the frequency of the motor speed control of the power saving operation, by adjusting the supply voltage to meet a certain speed the load torque requirements;
(2) According to the different motor operating conditions, raised the pressure frequency energy than the fuzzy control regulation, improved motor efficiency and to maintain a certain degree of dynamic response;
(3) proposed a model based on loss of vector control programs, vector control and energy control are taken into account iron losses, and the rated speed and rated speed less than energy-saving control vector were discussed, taking into account the system's quality control program dynamic performance, wide speed range and energy-saving operation.
Degree Year: 2010