GB2182216A

GB2182216A - Electric motor control

Info

Publication number: GB2182216A
Application number: GB08624923A
Authority: GB
Inventors: Karl E Brinkmann; Hans-Peter Schmidt
Original assignee: BRINKMANN ERNST IND VERWALT; K Ernst Brinkmann Industrieverwaltung
Current assignee: BRINKMANN ERNST IND VERWALT; K Ernst Brinkmann Industrieverwaltung
Priority date: 1985-10-23
Filing date: 1986-10-17
Publication date: 1987-05-07
Also published as: FR2591826A1; DE3537695A1; JPS62104486A; IT8612562A0; DE3537695C2; FR2591826B1; IT1215064B; ES2002043A6; GB8624923D0

Abstract

A control arrangement for varying the speed of rotation of an electric motor 12, is provided with various potentiometers 11 for setting various operating parameters of the motor, for instance the acceleration time, the deceleration time and the start-up boost. The potentiometers 11 are connected to a display by way of which the respectively set operating parameter of each individual potentiometer 11 can be displayed. Advantageously only one display 14 is provided for all potentiometers 11 and each individual potentiometer 11 can be separately called up by way of a selector switch 15 and the correspondingly set operating parameter can be displayed in the display 14. <IMAGE>

Description

SPECIFICATION Current converter The present invention relates two a current converter with adjustable operating parameters for varying the speed of rotation of electric motors, wherein there are provided a plurality of potentiometers for adjust ing various operating parameters, for example potentiometers for adjusting the voltage characteristic, the acceleration time, the deceleration time and the start-up boost.

Current converters ofthe general kind set forth are known per se. Such current converters are used to provide for stepless variation in the speed of rotation of electric motors. In order to provide for optimum loading conditions, it is necessaryforall operating parameters to be exactly adjusted to the operating condition which occur at any respective time, that is to say, those conditions which are governed buy a machine driven bathe electric motor.

As, in the case of the previously known current converters of the general kind setforth,the respect- ive set operating parameters can be determined only by means of expensive measuring devices and measuring processes, and the appropriate adjustment operation can also be carried out only by trained personnel.

The present invention is based on the problem of so designing a currentconverterofthe general kind set forth that setting of the most important operating parameters can be carried out and checked in a simple manner, while both the setting operation and also the monitoring operation are such that they can be carried out by less skilled personnel.

According to the present invention there is provided a current converterwith adjustable operating parametersforvarying the speed of rotation of electric motors, wherein there are provided a plurality of potentiometers for adjusting various operating parameters, such as potentiometers for adjusting the voltage characteristic, the acceleration time, the deceleration time and the start-up boost, wherein at least the potentiometersforadjusting said operating parameters are connected to a display means by way of which the respectively adjusted operating parameters of each individual potentiometer can be displayed.

The present invention makes it possibleforthe respectively set operating parameter of a potentiome terto be displayed immediately and without the assistance of expensive measuring equipment, while any change in the adjusted value is also immediately displayed. That makes it readily possibleforthevarious operating parameters to be adjusted even by less qualified personnel.

It is even conceivable that so-to-speak 'remote adjustment' is carried out insofaras highly qualified personnel at the manufacturer of the current conver tergivetelephone instructions to the less qualified personnel at the point of use of the arrangement, and those instructions are suitably carried into effect by the personnel on the spot.

The last mentioned possibility is particularly advantageous when operating conditions have changed in the course oftime and an adjustment, which has once been made, has to be suitably alte red.

For a better understanding ofthe present invention, and to show how the same may be carried into effect, reference will now be made by way of ex ampletotheaccompamying drawings, in which Figure lisa block circuit diagram of a current con verter of the invention for varying the speed of rota tion of an electric motor which is also shown only by way of indication, and Figures2to4areflowchartsforillustratingthe mode of operation of the currentconvertershown in Figure 1 in regard to operating parameter adjust ments.

A current converter of the invention which is ident ified by reference numberal 10 in the drawings is provided with a plurality of potentiometers 11 for adjust ing various operating parameters for operation of an electric motor indicated by reference numeral 12.

As the blockcircuitdiagram clearly shows, all the potentiometers 11 are connected by way of a computer 13 to a display means 14.

Each individual potentiometer 11 can be individually selected by way of a selector switch 15. The operating parameterwhich is predetermined bythe re respectively selected potentiometer is then directly displayed in the display means 14and anychange in an operating parameter by virtue of adjustment of the corresponding potentiometer 11 is also immediately displayed by way of the display means 14.

In the illustrated embodiment, there is only one display means 1 4for all the potentiometers 11, and each individual potentiometer 11 can be called up separately by way of the selector switch 15, as already mentioned above.

In an alternativeto that embodiment, itwill be app reciated that it is also possible for a separate display means 14to be associated with each potentiometer 11, although that is considerably more expensive in terms of structure. It will be appreciated that the con cept ofthe invention is also carried into effect with an expensive construction of that kind.

The flow charts shown in Figures 2 to 4 clearly set forth the mode of operation ofthecurrentconverter 10, in regard to adjustmentsto operating parameters.

As can be seen from Figure 2, the individual potentiometers 11 can be individually called up byway of the selector switch 15. Setting the selector switch 15 to give potentiometer 11 firstly causes the computer 13to call up only the setvalue of the selected potentiometer 1 1.Thatsetvalue is read in in aform which is converted for the computer 13 and processed in suitable computer programs, and stored. In addition, the value which is ascertained in the computer programs is subjected to further processing and displayed in the display means 14 in the form of an absolute value.

In Figure 2 for example position 5 shows the procedure involved in adjusting the acceleration time for the electric motor 12. After the appropriate potentiometer has been selected and the actual set value of that potentiometer has been read in,that set value is processed in a computer program 20. The computed value which is obtained in thatway represents a parameterforfurther computing operations which will be discussed hereinafter. That computed value is stored in a furthercomputer program 21 and also converted in such a way that the accieration time which is effectively provided by the corresponding setting of the potentiometer can be displayed as an absolute value in seconds in the display means 14.

The value stored in the program 21 is required for further computing operations, to which reference has already been made above.

Thatvalue is read in a further computer program 22 which is shown in Figure3fordetermining in what stages of a periodically circulating program procedure it is necessary to provideforthe increase infre quencywhich is necessary to obtain the desired ac- celeration time.

In the same manner as described above, for example positions 3 and 4 and corresponding computer programs 30 and 31 and a further computer program 32 (see Figure 4) provide for setting, displaying and producing the maximum and minimum frequencies F max and F min respectively. The values which are crucial for the start-up boost are set, displayed and produced for example at positions 1 and 2 and with corresponding computer programs 40, 41 and 42 (see Figure 3).

The corresponding values for "deceleration time" are set at position 6 as a further example in respect of setting operating parameters, by way of corresponding computer programs 50 and 51 and a further program 52 (see Figure 3).

Asubstantial advantage of the current converter according to the invention is that all adjustments can be made without it being necessaryforthat purpose to set the electric motor itself in operation.

Claims

1. A current converter with adjustable operating parameters for varying the speed of rotation of electric motors, wherein there are provided a plurality of potentiometers for adjusting various operating parameters, such as potentiometers for adjusting the voltage characteristic, the acceleration time, the deceleration time and the start-up boost, wherein at least the potentiometersforadjusting said operating parameters are connected to a display means by way of which the respectively adjusted operating parameter of each individual potentiometer can be displayed.

2. A current converter according to claim 1, wherein the common display means is provided for all the potentiometers and wherein each potentiometer can be called up separately byway of a selector switch and the adjusted operating parameter can be displayed in the display means.

3. Acurrentconverteraccording to claim 1, wherein a separate display means is provided for each potentiometer.

4. Acurrentconverterwith adjustable operating parametersforvarying the speed of rotation of electric motors, substantially as hereinbefore described with reference to the accompanying drawings.