Load torque estimating method and system, electromechanical control system and method and motor

Abstract

The invention discloses a load torque estimating method and system, an electromechanical control system and method and a motor. The load torque estimating method comprises that a practical mechanicalrotating speed of a rotation machine is received; and a pre-estimated load torque is calculated by a load torque estimator, the load torque estimator includes a closed-loop negative feedback system containing an error, a transfer function P / L of a controlled object, and a transfer function 1 / Js of a feedback link, J represents an inertia moment, s represents a differential function, and accordingto the transfer function P / L of the controlled object, P(s) / L(s)=-J(1.414*omega<n>s+omega<n><2>) / s, and omega<n> represents the bandwidth of the load torque estimator. The load torque estimator with the closed-loop feedback system including the error, the transfer function of the controlled object and the transfer function of the negative feedback link is used, the practical rotating speed of therotation machine is input, the pre-estimated load torque is obtained, so that the change rate of load torque does not influence estimation of the load torque any more, the load torque is estimated without offset, the problem that a present load torque estimation method has offset in load torque estimation is solved, and the load torque estimating accuracy is improved.

Description

technical field [0001] The invention relates to the field of electromechanical control, in particular to a load torque estimation method, system, electromechanical control system, method and motor. Background technique [0002] A typical electromechanical drive system such as figure 1 , where ω and J are the mechanical speed and moment of inertia of the rotating machinery respectively, and T e is the torque to drive the rotating machine, T d is the load torque that hinders the rotation of the rotating machine. Generally, T e is the measurable electromagnetic torque of the motor, but T d It varies with the load and has uncertainty. For electromechanical transmission systems that usually adopt closed-loop speed control, T d It is an external disturbance that affects the rotational speed of rotating machinery. In industrial fields such as metallurgy and steel rolling, due to the extremely high requirements on the dynamic speed drop and speed response of the motor, it is ...

AI Technical Summary

Problems solved by technology

[0005] The existing scheme assumes that the actual load torque T d The rate of change dT D / dt=0 (that is, remains unchanged), and in the actual electromechanical system, the load torque T d is always changing, dT D / dt≠0, so the observed by this observer and actual torque T d There are bound to be deviations, which lead to inaccurate estimation results, and the structure of the observer is relatively complicated, which needs to be determined after repeated debugging and testing. The design process is complicated and the technical requirements are high.

Images