JPS5856435B2 - AC machine rotation direction and rotation speed detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotational direction and rotational speed detection device for an alternating current machine.

Conventionally, the rotational direction and rotational speed of a reversible variable speed AC machine have been detected using a DC tachometer, an AC tachometer, etc., which are directly connected to the rotating shaft of the AC machine via a coupling device.

However, when using a tachometer in this way, there are disadvantages in that the compling device tends to loosen or bend, resulting in inaccurate readings, and also requires a considerable amount of space to install the tachometer, making it expensive. Ta.

Therefore, the inventor conducted extensive research and devised a method to detect the rotation direction button and rotation speed by calculating the electromotive force of the alternator by configuring an arithmetic circuit without using a tachometer. As a result, the phase of the magnetic flux was Since the electromotive force during forward rotation is 900 lags behind the electromotive force during reverse rotation and 900 ahead of the electromotive force during reverse rotation, by shifting the phase of the magnetic flux by 90° using a vector rotator, the phase-shifted magnetic flux vector has an E rotation with respect to the electromotive force vector. As a result of noting that the phase is sometimes in the same phase, and when the phase is reversed, the phase is opposite, it was found that the detection device should be configured as follows.

In other words, an electromotive force calculator and a magnetic flux calculator. A vector rotator is provided, and an electromotive force is calculated from the terminal voltage and current of the AC machine using an electromotive force calculator, a magnetic flux is calculated from this electromotive force using a magnetic flux calculator, and the phase of this calculated magnetic flux is calculated by a vector rotator. The magnetic flux vector advanced by 90 degrees and then phase-shifted is configured so that it is in phase with the electromotive force vector when rotating in the forward direction, and has the opposite phase when rotating in reverse, and an electromotive force rectifier is further provided to adjust the phase-shifted magnetic flux by the vector rotator. By synchronously rectifying the electromotive force in synchronization with either the positive or negative half-wave of the It has been found that the rotational speed can be easily detected.

Additionally, in addition to the above-mentioned calculation circuit, a magnetic flux rectifier that performs rectification in synchronization with the electromotive force rectifier is installed, and the magnetic flux phase-shifted by the vector rotator is synchronously rectified, making it independent of the rotational direction of the AC machine. The electromotive force rectifier is configured such that a direct current voltage indicating the absolute amount of magnetic flux is taken out, and further a divider is provided to divide the output voltage of the electromotive force rectifier by the output voltage of the magnetic flux rectifier. The synchronized pulls contained in the respective output voltages from the button and the magnetic flux rectifier are canceled and removed, and it is possible to extract a DC output voltage containing no pulls from the output terminal of the divider. Not only can the direction of rotation be detected based on the polarity of this DC output voltage, but also the ripple component can be detected. It was discovered that the rotational speed could be detected more precisely by determining the magnitude of the DC output voltage.

Therefore, a general object of the present invention is to provide a rotational direction and rotational speed detection device for an alternating current machine that can always detect the rotational direction button and rotational speed of an alternating current machine with stable accuracy using a simple configuration. .

In order to achieve this object, the present invention includes an electromotive force calculator that calculates an electromotive force from the terminal voltage and current of an alternating current machine, a magnetic flux calculator that calculates magnetic flux from the electromotive force, and a magnetic flux calculator that calculates a magnetic flux from the electromotive force. A vector rotator that changes the phase angle of the calculated magnetic flux with respect to the electromotive force based on the rotation direction of the alternator, and an electromotive force that synchronously rectifies the electromotive force in synchronization with the polarity of the magnetic flux phase-shifted by this vector rotator. and a rectifier, and is characterized in that it is configured to detect the rotational direction and rotational speed of the alternating current machine based on the polarity and magnitude of the output voltage of the electromotive force rectifier.

According to the above-mentioned detection device, the vector rotator changes the phase angle of the magnetic flux calculated by the magnetic flux calculator with respect to the electromotive force, so that it is in phase with the electromotive force in the case of forward rotation and is in phase with the electromotive force in the case of reverse rotation. It is preferable to configure the output to generate an output having an opposite phase.

The electromotive force rectifier includes a comparator amplifier that generates an output signal during the negative half-wave period of the output of the vector rotor, and a comparator amplifier that opens and closes in response to the intermittence of the output signal supplied from the comparator amplifier. , an electromotive force rectifying switching element that outputs an electromotive force calculated by an electromotive force calculator when the circuit is closed, and the rectified output voltage of each phase of this electromotive force rectifying switching element is combined and inverted. It can be constructed from an inverting amplifier.

As an alternative, the detection device may include a magnetic flux rectifier that rectifies the magnetic flux phase-shifted by the vector rotator in synchronization with an electromotive force rectifier, and the output voltage of the electromotive force rectifier is divided by the output voltage of the magnetic flux rectifier. By attaching a divider to calculate the voltage, the output voltage that does not include ripple is extracted from the output terminal of the divider, and the polarity and magnitude of the output voltage can be used to determine the rotational direction and rotational speed of the alternating current machine more accurately. This makes it possible to detect at a high level.

Additionally, in the above detection device, a magnetic flux rectifier 1d, a magnetic flux rectifying switching element that opens and closes in synchronization with the electromotive force rectifying switching element and outputs a magnetic flux phase-shifted by the vector rotator when the circuit is closed; It is preferable to include an inverting amplifier that combines and inverts the rectified output voltages of each phase of the magnetic flux rectifying switching element.

Next, embodiments of the rotational direction and rotational speed detection device for an alternating current machine according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a three-phase alternating current machine, terminal voltage detectors 12u and 12vw are connected between the u-v phase button and the V-W phase of this alternating current machine 10, and the U-phase conductor and V Connect current detectors 14u and 14v to the phase conductors.

Further, the output terminals of the terminal voltage detectors 12uv and 12vw and the current detectors 14u and 14v are connected to the input terminals of the electromotive force calculator 16, and the three-phase output terminals of the electromotive force calculator 16 are respectively connected to the magnetic flux calculator 18. The three-phase output terminals of the magnetic flux calculator 18 are connected to the input terminals of the vector rotator 20, respectively.

On the other hand, the three-phase output terminals of the electromotive force calculator 16 are connected to resistors R
□, R2, and R3 are connected to one terminal a of the electromotive force rectifying switching element 22, 24, and 26 consisting of three phases, and the other terminal is connected to the input terminal of the operational amplifier 28 by connecting the three phases at once. The input terminal (G) of the operational amplifier 28 is grounded, and the 13th input terminal of the operational amplifier 28 is connected to the output terminal P of the operational amplifier 28 via a resistor R.

In addition, the three-phase output terminals of the vector rotator 20 are connected to the column terminals of the three-phase comparison amplifiers 30, 32, and 34, respectively, and the force terminals of these are grounded, and the comparison amplifiers 30, 32, and 34 are connected to each operation signal input terminal CK of the electromotive force rectifying switching elements 22, 24, and 26.

Next, the operation of the apparatus of the present invention configured as described above will be explained.

Terminal voltage detector 12 between u-v phase button and v-w phase button
UV, 12vW, U phase, V phase current detector 14u 1
When each detection output from 4v is supplied to the electromotive force calculator 16, the electromotive force calculator 16 calculates the interphase electromotive force Euv of the three phases of the AC machine 10.

Evw and Ewu are calculated to generate these outputs.

In this case, the electromotive force during forward rotation and the electromotive force during reverse rotation are the second
As shown in Figure a, they are 180° out of phase.

These electromotive forces Euv, Evw, and Ewu are output to the magnetic flux calculator 18, and the magnetic flux calculator 18 performs the integration shown in the following equation to calculate the magnetic fluxes φuv, φVW9φwu.

As shown in FIG. 2bK, these magnetic fluxes are in phase 90' behind the electromotive force during normal rotation and 90' ahead of the electromotive force during reverse rotation.

The magnetic flux φUVt φvw'φwu is the vector rotator 20
, the vector rotator 20 performs the calculation shown in the following equation, and as shown in FIG. φUVtφvw, φWU are vector rotators 20
The signal is output from the output terminal of the comparator amplifier 30, 32, and 34 to each input terminal.

This phase-shifted magnetic flux φLIVj φvwy φwu is,
As shown in Figure 2 cK, the electromotive force Euv I E VW
With respect to IEwtt, they are in the same phase when rotating in the normal direction, and are in opposite phase when rotating in the reverse direction.

On the other hand, since the comparator amplifiers 30, 32, and 34 have their (a) input terminals grounded, ←) while positive power is supplied to the input terminals, the output terminals of the comparator amplifiers 30, 32, and 34 Although no output signal is sent out, ←) If a negative force is supplied to the input terminal, an output signal is sent from each output terminal to the operation signal input terminal C of the electromotive force rectification switching element 22, 24, 26. When the voltage is supplied, the electromotive force rectifying switching elements 22, 24, and 26 are closed.

Therefore, when the AC machine 10 rotates normally, the vector rotator 20
The negative output voltage from the output terminals of the comparator amplifiers 30, 32 .
34, and the output signal is output from the output terminal to the operation signal input terminal C of the switching elements 22, 24, 26, and when the switching elements 22, 24, 26 are closed, the output signal is output from the output terminal of the electromotive force calculator 16. 2, where the negative output voltage consists of a resistor R1゜RRR-t- and an operational amplifier 28;
3. 4 is supplied to the inverting amplifier, and the positive electromotive force rectified value EuVW shown in the left diagram of FIG. 2d is taken out from the output terminal P of the operational amplifier 28 as an output.

Furthermore, when the AC machine 10 is in reverse rotation, a negative output voltage from the output terminal of the vector rotator 20 is applied to the comparator amplifier 30.32.3.
When the switching elements 22, 24 and 26 are closed by the output signal of the comparison amplifier 30°32.34, a positive output voltage is applied from the output terminal of the electromotive force calculator 16 to the resistors RR1, 2°R3, R4f. ;, - and an operational amplifier 28;
As shown in the right diagram of Figure d, a negative electromotive force rectified value "uvw" is taken out as an output.

In this way, the rectified voltage taken out from the output terminal P of the operational amplifier 28 includes a pull, and the rotation direction of the AC machine 10 is detected by the polarity of this output voltage, and the magnitude of this output voltage is determined by the AC machine 10. The rotation speed can be detected because it is proportional to the rotation speed.

Next, the rotational direction and rotational speed of the alternating current machine according to the present invention is configured such that the rotational direction and rotational speed can be accurately detected and obtained by using the above-mentioned inventive device and removing the ripple from the rectified output voltage. An example of the rotational speed detection device will be described.

FIG. 3 shows another embodiment of the device of the present invention, and for convenience of explanation, the same components that are common to the embodiment shown in FIG.

That is, in this embodiment, the three-phase output terminals of the vector rotator 20 are connected to the three-phase output terminals through the resistors R5, R6, and R7, respectively.
Switching element for magnetic flux rectification consisting of phases 36°38.4
One terminal a of each of g) Connect the input terminal to the output terminal of the operational amplifier 42 via the resistor R.

In addition, each output terminal of the operational amplifier 28 button and the operational amplifier 42 is connected to the input terminals a and b of the divider 44.
The output terminal C of the divider 44 is connected to the output terminal Q of the detection device.

Next, the operation of the apparatus of the present invention configured as described above will be explained.

The electromotive force Euv shown in FIG.
, Evw, and Ewu are calculated, and the magnetic flux calculator 18 generates the magnetic flux φuv ? as shown in FIG. φvw and φWU are calculated, and the phase-shifted magnetic flux φuv tφvw tφwu is extracted from the output terminal of the vector rotator 20 as shown in FIG. 4 cK, and from the output terminal P of the operational amplifier 28 as shown in FIG. 4 d1. , the fact that electromotive force rectification values E with different polarities are taken out during forward rotation and reverse rotation is exactly the same as in the embodiment shown in FIG.

In this embodiment, the magnetic flux rectifying switching element 3
6゜38.40 performs opening and closing operations in synchronization with the electromotive force rectifying switching element 22゜24.26, and the outputs φuv, φvw, tφwu of the vector rotator 20 are resistors R, R,
The absolute value of the magnetic flux 1, which is independent of the rotational direction, is supplied from the output terminal P' to the inverting multiplier consisting of R, R and the operational amplifier 42, as shown in FIG. 4e.
φ′uvwl is retrieved.

That is, the output voltage Euvw of the operational amplifier 28 and the output voltage 1φuvwl of the operational amplifier 42 (1) are voltages that are rectified in synchronization with each other, so as shown in FIG. When the button is pressed, the pulsation value of the button push pull is 0.866 when the wave height value is 1.

This output voltage E and 1φ 1 are calculated by the divider 44
When outputted to the input terminals a i- and b of vW and divided,
Since both ripples are in phase, the ripple is completely removed, and from the output terminal C of the divider 44, the following equation, where K...
. . . Constant 2 n . . . The rotation speed n shown in the rotation speed can be taken out as shown in FIG. 4 f.

This detected value is positive for forward rotation and negative for reverse rotation, allowing the direction of rotation to be detected and containing no ripple.
Since the rotation speed is not f1, the rotation speed can be detected more accurately.

According to the device of the present invention, the rotational direction and rotational speed of the alternating current machine can be detected with stable accuracy using a simple configuration, and the effect of contributing to the improvement of alternating current machine control technology is extremely large.

In the past, if the device of the present invention was applied to a three-phase AC tachometer with a permanent magnet, the electromotive force calculator and the terminal voltage detector and current detector as power sources in the above-mentioned embodiments could be omitted. , it is possible to manufacture a brushless tachometer that is inexpensive and highly accurate.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the rotational direction and rotational speed detection device for an AC machine according to the present invention; FIG. 2 is a waveform diagram showing the operation of the device of the present invention shown in FIG. 1; and FIG. The figure is a block diagram showing a 531i embodiment of the device of the present invention, and FIG. 4 is a waveform diagram showing the operation of the device of the present invention shown in FIG. 10... AC machine, 12. 12...
...terminal v voltage detector, 14. 14... Current detector, 16... Electromotive force calculator, 18... Magnetic flux calculator, 20... Vector rotator, 22, 24
, 26...Switching element for electromotive force rectification, 2
8... operational amplifier, 30, 32, 34...
... Comparison amplifier, 36° 38.40 ... Switching element for magnetic flux rectification, 42 ... Operational amplifier,
44...Divider.

Claims (1)

[Scope of Claims] 1. An electromotive force calculator that calculates an electromotive force from the terminal voltage and current of an alternating current machine, a magnetic flux calculator that calculates magnetic flux from the electromotive force, and an electromotive force calculator that calculates a magnetic flux from the electromotive force. It consists of a vector rotator that changes the phase angle with respect to the electric power based on the rotation direction of the alternator, and an electromotive force rectifier that synchronously rectifies the electromotive force in synchronization with the polarity of the magnetic flux phase-shifted by the vector rotator. A rotational direction and rotational speed detection device for an alternating current machine, characterized in that the rotational direction and rotational speed of the alternating current machine are configured to be detected based on the polarity and magnitude of the output voltage of the electromotive force rectifier. 2. In the rotational direction and rotational speed detection device for an alternating current machine as set forth in claim 1, the vector rotator changes the phase angle of the magnetic flux calculated by the magnetic flux calculation unit with respect to the electromotive force to detect normal rotation. A rotational direction and rotational speed detection device for an alternating current machine configured to generate an output that is in phase with the electromotive force in the case of reverse rotation and in opposite phase with the electromotive force in the case of reverse rotation. 3. In the rotational direction and rotational speed detection device for an alternating current machine according to claim 1, the electromotive force rectifier includes a comparison amplifier that generates an output signal during a negative half-wave period of the output of the vector rotator; An electromotive force rectifying switching element that opens and closes in response to the intermittence of the output signal supplied from the comparator amplifier and outputs the electromotive force calculated by the electromotive force calculator when the circuit is closed; and this electromotive force rectifying switching element. An alternating current machine rotation direction and rotation speed detection device consisting of an inverting amplifier that combines and inverts the rectified output voltages of each phase. 4 An electromotive force calculator that calculates an electromotive force from the terminal voltage and current of an alternator, a magnetic flux calculator that calculates magnetic flux from the electromotive force, and an AC converter that calculates the phase angle of the magnetic flux calculated by this magnetic flux calculator with respect to the electromotive force. a vector rotator that changes the rotation direction of the machine based on the rotation direction of the machine; an electromotive force rectifier that synchronously rectifies the electromotive force in synchronization with the polarity of the magnetic flux phase-shifted by the vector rotator; a magnetic flux rectifier that rectifies the magnetic flux generated by the electromotive force rectifier in synchronization with the electromotive force rectifier;
a divider that divides the output voltage of the electromotive force rectifier by the output voltage of the magnetic flux rectifier, extracts an output voltage that does not include ripple from the output terminal of the divider, and determines the polarity of the output voltage. A rotational direction and rotational speed detection device for an alternating current machine, characterized in that the rotational direction and rotational speed of an alternating current machine are configured to be detected based on the rotational direction and rotational speed of the alternating current machine. 5. In the rotational direction and rotational speed detection device for an alternating current machine as set forth in claim 4, the vector rotating machine changes the phase angle of the magnetic flux calculated by the magnetic flux calculation unit with respect to the electromotive force to detect the rotation direction and rotational speed of the alternating current machine in the case of normal rotation. A rotational direction and rotational speed detection device for an alternating current machine configured to generate an output that is in phase with the electromotive force and in phase with the electromotive force in the case of reverse rotation. 6. In the rotational direction and rotational speed detection device for an alternating current machine according to claim 4, the electromotive force rectifier includes a comparison amplifier that generates an output signal during a negative half-wave period of the output of the vector rotator; An electromotive force rectifying switching element that opens and closes in response to the intermittence of the output signal supplied from the comparator amplifier and outputs the electromotive force calculated by the electromotive force calculator when the circuit is closed; and this electromotive force rectifying switching element. An apparatus for detecting the rotational direction and rotational speed of an alternating current machine, comprising an inverting amplifier that combines and inverts the rectified output voltages of each phase. 7 In the alternating current rotation direction and rotation speed detection device according to any one of claims 4 to 6, the magnetic flux rectifier opens and closes in synchronization with the electromotive force rectifying switching element, and the circuit is closed. An alternating current that is composed of a magnetic flux rectifying switching element that outputs the magnetic flux phase-shifted by the vector rotator, and an inverting amplifier that combines and inverts the rectified output voltage of each phase of the magnetic flux rectifying switching element. Machine rotation direction and rotation speed detection device.