Design And Research Of High-speed Wire Rod Finishing Mill Induction Motor

In the national economy, the use of wire spreads all over the departments. Along withthe development of technique, the rolling speed of the high-speed wire rod is also higher.The first generation was43m/s, and today’s100m/s. The electric drive system of highpower steel rolling machine should have very high dynamic response and high overloadcapacity. This area has been monopolized by DC motor drive system for a long time.Although the DC motor has good control performance, it has reversing problem whichlimits itself in improving its single capacity, overload ability, maintenance, atc. Along withthe rapid development of the power electronic technology, micro-electronics technologyand modern control theory, the AC frequency conversion speed control system can getgood dynamic performance. It has become the mainstream of the electric drive system andwill substitute for the traditional DC variable speed drive system step by step.At present in the steel rolling production line, asynchronous variable frequency drivesystem has been used for driving a lot of equipment such as flying shears, pinch machine,spinning machine. But synchronized variable frequency drive system is still the first choicefor finishing mill. Along with the wire disc being heavier and rolling speed increasing, thesynchronous drive system with complicated structure has been more and moreunconformable. The development of asynchronous variable frequency drive system used in high-speed wire rod finishing mill is consequentially.This paper is about the design of VVVF asynchronous motor and the rating power is6800kW. According to the process requirements of high speed wire rod finishing millproduction, this paper analyzes the work characteristics and overload ability of VVVFasynchronous motors. To ensure the reliability of the motor, this paper analyzes the rigidityof the frame and the force of the coil end. It also calculates the stress of the silicon steelplate, the end ring and the protecting ring, and the critical speed of the rotor. Consideringthe structure, this paper introduces the control strategy of the motor’s axial float. In view ofthe special installation position, this paper introduces its side-mounted cooling system.Finally, based on the experimental data, this paper gives a summary. It proves the validityof this design.