METHOD FOR DETERMINING AT LEAST ONE PROPERTY OF A ROTATIONAL MOVEMENT OF A THREE-PHASE ROTARY CURRENT MACHINE IN GENERATOR OPERATION AND ELECTROMECHANICAL DRIVE

Abstract

A method for determining at least one property of a rotational movement of a three-phase rotary current machine in generator operation, with an electrical parameter for a phase voltage of the relevant phase of the three-phase alternating voltage of the rotary current machine generated in generator operation being continuously recorded metrologically for each of the three phases. Three electrical parameter pairs are formed from the three electrical parameters, whereby the three electrical parameter pairs respectively include electrical parameters of a first and a second phase, electrical parameters of the second phase and a third phase, and electrical parameters of the third phase and the first phase. A sign of a difference between the electrical parameters of each parameter pair is continuously determined. The property of the rotational movement is determined from change times corresponding to times of immediately successive sign changes of the differences between the three parameter pairs.

Claims

1. A method for determining at least one property of a rotational movement of a three-phase rotary current machine in generator operation, wherein an electrical parameter for a phase voltage of the relevant phase of the three-phase alternating voltage of the rotary current machine generated in generator operation is continuously recorded metrologically for each of the three phases, wherein three electrical parameter pairs are formed from the three electrical parameters, whereby a first electrical parameter pair comprises the electrical parameters of a first and a second phase, a second electrical parameter pair comprises the electrical parameters of the second phase and a third phase, and a third electrical parameter pair comprises the electrical parameters of the third phase and the first phase, wherein a sign of a difference between the electrical parameters of each parameter pair is continuously determined, and wherein the property of the rotational movement is determined from change times (t.sub.4,1, t.sub.4,2, t.sub.4,3, . . . , t.sub.5,1, t.sub.5,2, t.sub.5,3, . . . , t.sub.6,1, t.sub.6,2, t.sub.6,3, . . . ), wherein the change times (t.sub.4,1, t.sub.4,2, t.sub.4,3, . . . , t.sub.5,1, t.sub.5,2, t.sub.5,3, . . . , t.sub.6,1, t.sub.6,2, t.sub.6,3, . . . ) correspond to times of immediately successive sign changes of the differences between the three parameter pairs.

2. The method according to claim 1, wherein the property of the rotational movement is a direction of rotation of the rotary current machine, wherein the direction of rotation is determined from a time sequence of the sign change of the three parameter pairs determined by the change times (t.sub.4,1, t.sub.4,2, t.sub.4,3, . . . , t.sub.5,1, t.sub.5,2, t.sub.5,3, . . . , t.sub.6,1, t.sub.6,2, t.sub.6,3, . . . ).

3. The method according to claim 1, wherein the property of the rotational movement is a rotational speed measure of the rotary current machine, wherein time differences are determined from the change times (t.sub.4,1, t.sub.4,2, t.sub.4,3, . . . , t.sub.5,1, t.sub.5,2, t.sub.5,3, . . . , t.sub.6,1, t.sub.6,2, t.sub.6,3, . . . ) and the rotational speed measure is determined from the time differences and a pole pair count of the rotary current machine.

4. The method according to claim 3, wherein the property of the rotational movement is a rotational speed of the rotary current machine, wherein the rotational speed is determined from the rotational speed measure and a pole pair count of the rotary current machine.

5. The method according to claim 4, wherein the rotational speed ? is determined from a time difference ?t and the pole pair count p of the rotary current machine according to the following calculation rule: $?=\frac{\frac{360?}{6p}}{?t}$

6. The method according to claim 3, wherein the property is an average rotational speed, wherein the average rotational speed is an average value of a plurality of rotational speed measures or rotational speeds determined according to one of claims 3 to 5.

7. The method according to claim 1, wherein differences of the parameter pairs ?U.sub.1,2, ?U.sub.2,2, ?U.sub.2,1 of the electrical parameters for the phase voltages U.sub.1, U.sub.2, U.sub.3 are determined at determination times t according to the following calculation rules:
?U.sub.1,2(t)=U.sub.1(t)?U.sub.2(t)
?U.sub.2,3(t)=U.sub.2(t)?U.sub.3(t)
?U.sub.3,1(t)=U.sub.2(t)?U.sub.1(t)

8. The method according to claim 1, wherein the signs of the differences are determined by an electronic comparator.

9. The method according to claim 1, wherein the differences and/or the signs of the differences are determined continuously at predefined time intervals.

10. The method according to claim 9, wherein the predefined time intervals are predefined such that the at least one property is determined with an accuracy of at least 10%.

11. An electromechanical drive for actuating of a leaf, in particular a door leaf or a window leaf, rotatably and/or displaceably mounted on a structural element, wherein the electromechanical drive has a three-phase rotary current machine, wherein a drive shaft of the rotary current machine is operatively connected to the leaf via a power transmission device when the electromechanical drive is mounted as intended on the leaf and/or the structural element, so that a movement of the drive shaft in motor operation of the rotary current machine causes a movement of the leaf, wherein a movement of the leaf in generator operation of the rotary current machine causes a movement of the drive shaft, characterized in that the electromechanical drive has a determining device, wherein the determining device has measuring elements for each of the three phases for recording an electrical parameter for a phase voltage of the relevant phase of the three-phase rotary current of the rotary current machine generated in generator operation, wherein the measuring elements are connected to an electronic evaluation unit of the determining device in a wired or wireless manner so as to transmit data, wherein the determining device is configured to carry out the method according to claim 1.

12. The electromechanical drive according to claim 11, wherein the evaluation unit is a microcontroller.

13. The electromechanical drive according to claim 12, wherein the microcontroller has integrated comparators and the measuring elements are connected to comparator inputs of the comparators of the microcontroller in an electrically conductive manner.

14. The electromechanical drive according to claim 11, wherein the rotary current machine is an axial or a radial flux machine.

15. The electromechanical drive according to claim 11, wherein the electromechanical drive is a swing door leaf or sliding door or revolving door drive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further advantageous configurations of the method according to the disclosure and the electromechanical drive according to the disclosure are explained in more detail on the basis of exemplary embodiments represented in the drawing.

[0029] They show:

[0030] FIG. 1 three diagrams with schematically represented courses of phase voltages of a rotary current machine in generator operation as well as the determination of change times, and

[0031] FIG. 2 a schematically represented sectional view of an electromechanical drive in which the method according to the disclosure can be used.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 shows, in the first diagram, schematically represented time courses of phase voltages 1, 2, 3 of phases of a three-phase rotary current machine in generator operation. The phase voltages 1, 2, 3 each have a sinusoidal course and are thereby 120? out of phase with each other.

[0033] In the second diagram of FIG. 1, the phase voltages 1 and 2 from FIG. 1 are represented as well as the difference 4 between the two phase voltages 1 and 2. This difference 4 also has a sinusoidal course with a larger amplitude than the phase voltages 1 and 2. If the phase voltages 1 and 2 have the same amplitudes, the amplitude of the difference 4 would be ?3 times larger than the amplitude of phase voltages 1 and 2. For the sake of clarity, only the difference 4 between the phase voltages 1 and 2 is represented in FIG. 2. The course of the differences between the phase voltages 2 and 3 and 3 and 1 corresponds to the course of the difference 4, shifted in phase by 120? or 240?.

[0034] Change times t.sub.5,1, t.sub.5,2, t.sub.5,3, . . . of the difference 4 as well as change times t.sub.4,1, t.sub.4,2, t.sub.4,3, . . . and t.sub.6,1, t.sub.6,2, t.sub.6,3, . . . of the differences not represented are used to determine the properties of a rotational movement of the three-phase rotary current machine in generator operation, with the change times corresponding to times of immediately successive sign changes of the differences 4 between the three parameter pairs. If the change times are determined continuously or with a sufficiently large sampling frequency, the change times correspond to the times of the zero crossings of the differences 4, as is schematically illustrated in the third diagram of FIG. 1 on the basis of the zero crossings of the difference 4 represented in the second diagram. The change times t.sub.4,1 . . . t.sub.5,1 . . . and t.sub.6,1 . . . are represented in FIG. 1 as t_41 . . . , t_51 . . . and t_61.

[0035] FIG. 2 schematically represents a sectional view of an electromechanical drive 5 for actuating a leaf, in particular a door leaf or a window leaf, rotatably and/or displaceably mounted on a structural element. The electromechanical drive 5 has a three-phase rotary current machine 6, which is configured as an axial flux machine. A drive shaft 7 of the rotary current machine 6 is operatively connected to the leaf, not represented, via a power transmission device 8. The power transmission device 8 comprises a gear 9 connected to the rotary current machine 6, and a lever 10. This converts a movement of the drive shaft 7 into a movement of the leaf during motor operation of the rotary current machine 6. A movement of the leaf in generator operation of the rotary current machine 6 causes a movement of the drive shaft 7 via the power transmission device 8. The electromechanical drive 5 also has a determining device 11 with an evaluation unit 12 and measuring elements, which are not represented and which are connected to the evaluation unit 12 so as to transmit data. With the measuring elements, an electrical parameter for a phase voltage of the relevant phase of the three-phase rotary current of the rotary current machine 6 generated in generator operation is determined for each of the three phases of the rotary current machine 6 and processed by the evaluation unit 12. The evaluation unit 12 is thereby configured such that a property of the rotational movement of the rotary current machine 6 in generator operation can be determined with the evaluation unit 12 from the electrical parameters for the phase voltages recorded with the measuring elements.