Gorobets Nickolay

Department: Department: Electrotechnical

Chair: Electrical Drive and Automatization of Production Facilities

Subject of master's thesis: Research of moderns servo-motors en base of motor synchronous motor with permanent magnet

Research manager: Tolochko Olga

Technical consultant: Rozkarayka Pavel

Introduction

      Until recently, in the driving technique is mainly used DC motors. At present, however shifting the emphasis in the drive system of the DC motor to the engine alternators. The tendency to move to AC synchronous motor is particularly apparent in servo technique, which is always performed with the use of DC motors. Using the design features of the engines, advances in electronics, the development of regulatory systems has allowed to raise the quality of regulation in servo system to a new level. What is certainly a pressing issue for many industries where a high requirements for electric power.

Servo Definition, classification, history of development, the application

      Servo - this drive system, which in a broad range of speed control provides dynamic, high-precision motion and sells them a good repeatability.

In the modern production of servo makes high demands on the following parameters:

• Positioning accuracy;
• Range management;
• Uneven speed;
• The ability to transfer;
• High dynamics.

      Actuators are the most high-tech electric field. At the moment actuators are used in high equipment following industries: food processing, building materials, packaging, material handling - transport mechanisms.

      Originally servosistem dominated drive to DC. This was due to the simplicity of implementation of laws on the management of tension anchors. As a control device applied electrical amplifiers, transistor and thyristor controllers. Managing speed and the time it was analog, with all its attendant problems of noise immunity in a broad range of speed regulation. To measure the actual speed of the feedback channel used tahogeneratory DC.

      Improving the dynamic characteristics of servo was towards the creation of the DC motor with a small moment of inertia. In the framework of obtaining a small moment of inertia of the rotor was the decision of the receipt of a cylindrical nonmagnetic armature. To do this in the early 70-ies have been widely used permanent magnets from rare earth materials, providing a high value of induction in the air gap and high torque.

      Research brushless motors, which can be used in actuators, have been launched since the mid 70-ies.

      In contrast to the usual layout of the DC motor developers came forward to the new solution: to anchor the stator, the field excitation on the rotor. So there brushless DC motors, or motors with electronic commutation.

      These electric vehicles are a fundamentally CD synchronous motors with permanent magnets, in which the position of the rotor is controlled by a simple pulse sensor status.

      In addition to the electronic contactless switching, and low wear, this type has the following advantages:

• reduced moment of inertia due to the absence of windings on the rotor;
• ease of cooling, because heat from the stator is preferable than the rotor;
• increased efficiency, since there are no losses associated with the winding excitation.

      Parallel to this, and also developed in response to the application of AC induction motor as a brushless servo.

      On the other hand, the development of brushless motors were carried out theoretical studies on the so-called sinusnoy switching servo.

      It is with the engine switched sinusnoy is a board with permanent magnets, with all the benefits listed above. However, the rotor position sensor in this case serves rezolver, sinusoidal output signal which is controlled by the stator current of the machine.

      The above are three types of brushless drives are used currently.