JPH03245783A - Overload predicting device for motor - Google Patents

Abstract

PURPOSE:To prevent unnecessary line stoppage by regarding the feedback value of load from a motor drive in a time series manner by a systematic controller, predicting and notifying a time until overload is detected and predicting overload in a motor controller. CONSTITUTION:A control target value generator 17 previously expecting load currents flowing through a motor 5 and setting a target value, a motor controlled variable generator 18 measuring load currents 4 actually flowing through the motor 5 and generating a corresponding controlled variable, an overload detector 6 detecting the status of overload from the comparison of an output from the motor controlled variable generator 18 and an output from the control target value generator 17, and an overload detecting predicting equipment 15 controlling an overload countermeasure from an output signal from an overload detector 6 and a previously assumed time series-like overload status are provided. Accordingly, an overload detecting predicting function is added to a systematic controller 1, and a time until overload is detected is notified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an overload prediction device for a motor used in a paper machine line or the like.

(Prior Art) Conventionally, a systematic controller outputs a speed target value or a torque target value, and a motor drive device that receives the output outputs a current value or frequency to the motor to protect the motor without prior notice. The electric motor was stopped. Overload detection is performed only by the motor drive device, and the resulting overload detection signal is output to the controller.

(Issue 8 to be solved by the invention) If the electric motor drive device detects an overload and stops the electric motor, paper breaks will occur on the paper machine line, forcing the entire line to stop. . Therefore, from a system perspective, line stoppage due to overload has not been taken into consideration.

[Configuration of the Invention (Means for Solving the Problem) The present invention includes a control target value generator that predicts the load current flowing through the motor in advance and sets a target value, and a control target value generator that measures the load current that actually flows through the motor and responds accordingly. a motor control amount generator that generates a control amount to be controlled; an overload detector that detects an overload situation by comparing the output of the motor control amount generator with the output of the control target value generator; and the overload detector. This is an overload prediction device for an electric motor, which includes an overload detection predictor that controls overload countermeasures based on an output signal from the motor and a time-series overload situation assumed in advance.

(Function) In a paper machine line motor control device consisting of a motor drive device and a systematic controller, the systematic controller captures the load feedback value from the motor drive device in time series, and calculates the time until overload detection. Predicts and announces overloads in paper machine line motor control devices.

(Example) Next, an example of the present invention will be described. FIG. 1 shows a control target value generator 17 that predicts the load current flowing through the motor 5 in advance and sets a target value, and a motor control value generator 17 that measures the load current 4 that actually flows through the motor 5 and generates a corresponding control amount. Generator 1
8, an overload detector 8 that detects an overload situation by comparing the output of the motor control amount generator 18 and the output of the control target value generator 17, and the output signal from the overload detector 6, This figure shows an overload prediction device for an electric motor, which includes an overload detection predictor 15 that controls overload countermeasures based on assumed time-series overload situations.

That is, as shown in FIG. 4, an overload detection and prediction function is added to the systematic controller, and the time until overload detection is notified, which is used as a trigger for taking systematic measures.

As a technical means, the time until overload detection is calculated and notified by imitating the method used by the electric motor drive device to detect overload, and by looking at the method in chronological order. Therefore, although line stoppage due to overload has not been taken into consideration in the system, line stoppage due to overload can be known in advance.

In FIG. 4, the overload detection predictor 15 inputs the output (actual control value) of the motor control amount generator, and
The overload detection time is predicted and notified by comparing the time control amount and integrating the difference.

This makes it possible to take avoidance measures before detecting an overload, making it possible to systematically prevent the line from stopping.

Incidentally, FIG. 2 shows overload detection when T>To-.

[Effects of the Invention] According to the present invention, overload detection can be known in advance, and unnecessary line stoppages can be prevented.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an overload prediction device showing an embodiment of the present invention. 2 and 3 are explanatory diagrams of overload detection, and FIG. 4 is a configuration diagram showing details of FIG. 1. 6... Overload detector 15... Overload detection predictor 17... Control target value generator 18... Motor control amount generator

Claims (1)

[Claims] A control target value generator that predicts the load current flowing through the motor in advance and sets a target value, a motor control amount generator that measures the load current that actually flows through the motor and generates a corresponding control amount, and controls the motor. an overload detector that detects an overload situation from a comparison between the output of the quantity generator and the output of the control target value generator, and an output signal from the overload detector and a time-series overload assumed in advance. An overload prediction device for an electric motor, comprising an overload detection predictor that controls overload countermeasures based on the situation.