Study And Application Of Load Sharing For Withdrawal Straightener Of Bloom Continuous Casting Machine

The straightening machine is one of the most important equipment in the dasting machine of steelmaking. The straightening machine is one of the most important equipment in the continuous casting machine of steelmaking,The normal operation can guarantee continuous casting machine to run continuously. Billet straightening machine, due to tensile resistance largely, there are usually multiple motor to drive. In the continuous production process, changes in process conditions and equipment conditions cause different load of each motor, some motors load increase or some load reduce. As the roller load deviation reaches a certain degree and last a long time, the inverter will stop running frequently and mechanical equipment damage. Therefore, to ensure the motor load of the straightening machine in the proper range and to reduce equipment failure become an important work of equip maintenances.Through long-term observation, we found the continuous casting machine exist large differences between each of flows, and it is difficult to establish a unified model control. Based on the process and equipment requirements and in-depth study of the straightening machine load, we find a method of controlling motor torque which combines fuzzy control and PID control to solve the serious uneven load. The main research works are as follows:First of all, we compared the average distribution with percentage distribution method in the control load of continuous casting machine commonly used, and studied the use for reference experience and shortcomings, and determine the motor load given standard: when the motor load is too large, in rated load device as a given; when the load of motor is negative in regenerative braking load, to close to zero as the given.Second, for each motor itself, we look at as a single input single output system to use PID control.Third, for the strong coupling problem of each adjacent motor, according to the long-term artificial adjustment experience, we use fuzzy control method to adjust, in order to solve the drawbacks of single motor to adjust the same cause other motor adjustment.Finally, we test the program through SIEMENS simulator and set the function for use and exit plan, and use function in fields.Through field test and use, the motor load is controlled in withstand range of the device, and meet the technical requirements. Avoid due to equipment failure caused by different maintenance personnel on different adjustment strategies, reduce working strength maintenance.