JPS58195488A - Phase angle arithmetic circuit - Google Patents

Abstract

PURPOSE:To readily obtain an electric angle data of a rotor for an induction motor by providing a numeric value setter, a counter and a memory, and reading out the phase angle data of a rotor from the memory. CONSTITUTION:A phase angle arithmetic circuit has a numeric value setter 7, an up-down counter 10 and a memory 12. The setter 7 sets the repetition number of 2-phase signal which is outputted from a detector 2 that detects the rotating speed of a rotor for an induction motor 1. The counter 10 adds repeatedly the 2-phase signal between the zero and the numeric value which is set by the setter 7 when a rotor normally rotates, and subtracts repeatedly the 2-phase signal between the numeric value set by the setter 7 and the zero. The phase angle data corresponding to the counted output value of the counter 10 is read out by the memory 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase angle calculation circuit suitable for use in calculating a rotational phase angle of a rotating body such as a rotor of an induction motor.

When attempting to control the rotational speed of an induction motor to the same level as a DC motor, a so-called vector control method is usually used in which the current vector of the seventh winding is divided into a magnetic flux generating valve and a torque generating portion and each is controlled independently.

In this case, since the current vector of the above/sub-winding is calculated based on the phase angle of the magnetic flux vector, the phase angle of the magnetic flux vector must be found first, and furthermore, the phase angle of this magnetic flux vector is calculated based on the phase angle of the magnetic flux vector. Since it is the sum of the phase angle of the rotor of the electric motor and the subphase angle, the phase angle of the rotor must be calculated correctly.

In view of the above circumstances, it is an object of the present invention to provide a phase angle calculation circuit for a rotating body suitable for use in calculating the phase angle of a rotor of an induction motor.

Hereinafter, one embodiment of the present invention will be explained in detail with reference to the drawings. Fig. 7 shows a phase angle calculation circuit according to the present invention as a circuit for calculating the rotor phase angle (actually, electrical angle) of an induction motor. FIG. 2 is a circuit diagram showing the configuration of an embodiment when applied to. In this figure, numeral 1 is an induction motor, and numeral 2 is an induction motor 1.
This is a rotation speed detector that detects the rotation speed of the motor shaft (i.e., rotor) of the motor. This rotational speed detector 2 receives a co-phase pulse signal ρ1, which has a repetition frequency corresponding to the rotational speed of the rotor of the induction motor l. gD2, and these pulse signals φ1. The phase relationship of φ2 is that when the rotor is rotating normally, the phase of the pulse signal φ2 is delayed by ρ degrees from the phase of the pulse signal Φ1, as shown in Fig. 2. If they are reversed, the phase of the pulse signal Φl will be delayed by 0 degrees from the phase of the pulse signal Φ2, as shown in FIG.

1. Referring again to FIG. 7, reference numeral 3 indicates a phase angle calculation circuit according to the present invention. In this phase angle calculation circuit 3,
A D-type FF (hereinafter abbreviated as D-type FF) 4 determines the direction of rotation of the rotor. The data terminal I)C of this D-type FF is supplied with the pulse signal φ1 via the terminal 5a, and the trigger terminal TK is supplied with the terminal 5b.
A pulse signal φ2 is supplied via the. This D-type FF 4 is in a set state when the rotor rotates in the normal direction, and is in a reset state when the rotor rotates in the reverse direction. Nantes Gate 5
is DI! ! The NAND gate 5 calculates the NAND of the signal at the set output terminal Q of the FF and the pulse signal gs1, and when the rotor is rotating normally, the inverted signal (10') of the pulse signal pulse signal) is output.

In addition, the Nant's gate 6 takes the NAND of the signal between the reset output terminals of the D-type FF and the pulse signal Φl. ('O' pulse signal) is output. The numerical value setter 7' receives a pulse signal f61 outputted from the rotational speed product 〒2 during one rotation of the rotor.
Or, with a setting device for setting the number of pulses of the pulse signal φ2, i1''I, (for example, each one of the contacts is connected) 1 is grounded, and each other contact is connected to a pull-up resistor 8-1 to 8'!f
-m consists of m switches 9-1 to 9-m connected to *. The number setter 7 outputs the number of pulses set by the operator VC as m-bit data SD (code signal). Reference numeral 10 is an m-bit up/down counter, which adds and counts the pulse signal of 'θ' supplied from the Nantes gate 5 to the clock input terminal UP, and which is supplied from the Nantes gate 6 to the clock input terminal DNK. 0' pulse signal is subtracted and counted, and if the load terminal LK'l' signal is supplied, the data SD supplied to the data input terminal Di is preset, and the clear input terminal CLK'l' signal is supplied. VC@ is configured to output a '1' signal from the borrow output terminal B when the count value changes from "0" to "-1".

The borrow output terminal B of this up/down counter 10
is connected to the load terminal. Reference numeral 11 is a comparator, and this comparator 11 is connected to one data input terminal AK.
The supplied data SD is compared with the count output data CD of the up/down counter 10 supplied to the other data input terminal B, and when both data are correct, the output terminal A=
A '1' signal is output from B. This output terminal A=Bti
It is connected to the clear input terminal CL of the up/down counter 10. In addition, in the above part, D type FF4
, the Nant gate 5.6, the up/down counter 10, and the comparator 11 correspond to the counting circuit in the present invention. Reference numeral 12 denotes a waveform memory in which phase angle data of the four trochanters written in ^IJ are stored as electrical angle data corresponding to the number of poles of the induction motor 1. The output data C of the upda run counter 10 is supplied to each address vcIIi of this waveform memory 12 and the address input terminal AD.
While D changes from "0" to rsD'J, that is, while the rotor makes one revolution, the electrical angle data PD output from the data terminal changes from "0" to " Data is stored in which a linear change up to 2π'' is repeated once. The example shown in this figure shows the case where the induction motor has one pole.

According to the above configuration, if the induction motor 1 rotates forward, the up/down counter 10Fi pulse (1) can be cleared to zero every time it reaches 1. Therefore, in this case, the up/down counter 0 will linearly go from "0" to rSDJ. As a result, the waveform memory 2 repeatedly outputs electrical angle data PD that increases linearly from "0" to "2π" according to the number of poles. When the 7I fermentation motor 1 reverses, the up/down counter 0 subtracts and counts the pulse signal Φ1.

In this case, the up/down counter 0 is preset to the value rsDJ every time a borrow is output.

Therefore, in this case, the up/down counter -0 is rs
Do not repeatedly output data CL that decreases linearly from DJ to "0", and as a result, the waveform memory 2 becomes "2".
It is rc to repeatedly output the electrical angle data PD which decreases linearly from 'π' to ',:□O' according to the extreme mountain pass.

In this embodiment, if the rotation speed detector 2 has a different number of output pulses per rotation of the rotor, it is sufficient to set the same number of output pulses with the numerical setting device 7, and the V54 electric motor 1 with a different number of poles, the electrical angle data stored in the waveform memory 2 may be changed to match the same number of poles.

As is clear from the above description, the phase angle calculation circuit according to the present invention is provided with a numerical value setter, a counting circuit, and a memory, and the phase angle data of the rotating body is read from this memory. Even if the number of repetitions of the signal output from the detector during one revolution of the rotating body is different, correct phase angle data can be obtained by simply changing the value set on the numerical setting device. When obtaining the electrical angle data of the rotor of the motor, even if the number of poles of the induction motor is different, the correct electrical angle data can be obtained simply by changing the contents of the memory.

4. ,. Ayu7E・1□・: ・[: FIG. 1 is a circuit diagram showing a configuration when an embodiment of the present invention is applied to a circuit for calculating the rotor electrical angle of an induction motor.
Figures 2 and 3 are waveform diagrams showing the one-phase signal of the rotation speed detector in the same embodiment when the induction motor is rotating forward and reverse, and Figure μ is the waveform diagram in the same embodiment. FIG. 3 is a diagram showing electrical angle data stored in a memory.

1... Induction motor, 2... Rotation speed detector, 3... Phase angle calculation circuit, 4...
D-type flip-flop, 5.6...Nant gate, 10...up/down counter, 11...
...Comparator, 12... Memory (waveform memory).

Claims (1)

[Claims] a numerical setting device for setting the number of repetitions of a co-phase signal output from a rotational speed detector of the rotating body during seven rotations of the rotating body; and a value setting device that sets the number of repetitions to zero when the rotating body is rotating in the normal direction. The co-phase signal is repeatedly added and counted between the numerical value set in the value setting device, and when the rotating body is reversed, the co-phase signal is added between the number 1-1 and zero set in the numerical value setting device. A counting circuit that repeatedly subtracts and counts the signal, and phase angle data are stored in advance in correspondence to the count value output by the counting circuit, and when the output count value is supplied from the counting circuit, the same output count value is obtained. 1. A phase angle calculation circuit comprising: a memory from which corresponding phase angle data is read.