WO2002021678A1

WO2002021678A1 - A device for programmed control of three-phase and four-phase step motors

Info

Publication number: WO2002021678A1
Application number: PCT/AM2001/000005
Authority: WO
Inventors: Vahan Harutyunyan; Ashot Muradyan
Original assignee: Vahan Harutyunyan; Ashot Muradyan
Priority date: 2000-09-06
Filing date: 2001-03-01
Publication date: 2002-03-14
Also published as: AU2001240309A1

Abstract

The invention relates to automatics, electrotechnics and can be used for multi-mode control of three-phase and four-phase step-motors with permanent magnet, variable reluctance and hybrid rotors, acting in electrical drives of the executive mechanisms of robots, machine tools and computer peripherals. The aim of the invention is the expansion of the functional possibilities of the device through ensuring of all possible unipolar and bipolar phase commutation regimes of three-phase and four-phase step-motors. The device contains four multiplexers, binary three-digit counter, elements 2OR, 3AND, inverter, buses for setting commutation regimes, two groups of power amplifiers, two power sources, four elements NOT and four elements 2AND. The presented device has wide functional potential and favorably differs from the analogous devices as it ensures 32 various phase commutation regimes in total, i.e.12 regimes for three-phase step and 20 regimes for four-phase step motor.

Description

A Device for Programmed Control of Three-Phase and Four-Phase Step Motors

This invention refers to the spheres of automatics and eletrotechnics and can be used for multi-mode control of both three-phase and four-phase step motors with permanent magnet, variable reluctance and hybrid rotors in elecrical drives of the executive mechanisms of robots, machine tool control systems and computer peripherals.

A device for multi-mode control of m-phase step electrical motor is known [1], which contains the corresponding number of multiplexers and power amplifiers, control signal source, reversible binary impulse counter, logical element 20R and buses of regime setting of phase commutation of the motor in case of the separate control of three- or four-phase step motors.

The device is imperfect because its functional possibilities are limited to provision of only unipolar phase commutation regimes for the step motor.

The closest in terms of technical essence to the presented device is the device [2] for programmed control of three-phase and four-phase step motors, containing the first, second, third and fourth multiplexers with two control and four information inputs, binary reversible three-charge impulse counter with clock, initial setting, reverse, permit and parallel information recording inputs, the logical elements 2OR, 3AND and inverter, the first, second, third, fourth and fourth buses of phase commutation regime, and the second, third, fourth and first information inputs of respective first, second, third and fourth multiplexers are connected to the second input of parallel information recording of the counter and to the common zero bus of the power supplies, the fourth, first, second and third information inputs of the respective first, second, third and fourth multiplexers are connected to the first bus of the phase commutation regime setting, the first, second and fourth information inputs of the respective first, second and fourth multiplexers are connected to the second bus of phase commutation setting, the third information input of the third multiplexer is connected to the third bus of phase commutation regime setting, the third, fourth, first and second information inputs of the respective first, second, third and fourth multiplexers are connected to the output of element 2OR, the first input of which is connected to the fourth bus of phase commutation regime setting, and the second input is connected to the output of the first counter stage, the first and second control inputs of all multiplexers are connected to the respective outputs of the second and third counter stages and, at the same time, to the first and second inputs of the 3AND element, the third input of which is connected to the fifth setting bus of phase commutation regime, and the output is connected to the input of the information parallel recording permit of the counter, the inverter input is connected to the reversing output of the counter, and the output is connected to its first and third inputs of parallel information recording.

This device is imperfect as well because the functional possibilities are limited to provision of only unipolar phase commutation regimes of three- phase and four-phase step motors.

The purpose of the presented invention is the expansion of the functional possibilities of the device through provision of all possible unipolar and bipolar commutation regimes of three-phase and four-phase step motors.

The set goal is achieved through introducing into the device for the programmed control of three-phase and four-phase step motors additional first and second groups of four power amplifiers connected to each other respectively and constituting for each control canal half-bridges of step motors phase commutation, the first source of positive polarity for supply of the first group power amplifier, the second supply of negative polarity for supply of the second group power amplifiers, a group of four logical elements 2AND and the sixth bus of phase commutation regime setting, and each canal of motor control the multiplexer output is connected to the control input of the first group power amplifier of the given canal and to the input of NOT element simultaneously, the first input of 2AND element of each canal is connected to the output of NOT element of the given canal, the second input is connected to the additional sixth bus of phase commutation regime setting, and the output is connected to the control input of the second group power amplifier of the given canal.

On Figure 1 you can see the functional scheme of the proposed device for programmed control of three-phase and four-phase step motors, Figures 2-4 present the schemes of connection of three-phase step motor to the power amplifiers in the form of "star" with and without zero common point respectively, as well as in the form of "triangle", corresponding tables of control and phase commutation regimes (Tables 1-4); on Figures 5-7 one can see the schemes of connection of the four- phase step motor to the power amplifiers in the forms of "star" with and without common zero point respectively, as well as in the form of a "quadrangle", corresponding tables of control and phase commutation regimes (Tables 5-8).

The device contains (Figure 1) four multiplexers 1.1-1.4, binary reversible three-digit impulse counter 2 with clock, reset, reverse, permit and parallel information recording inputs, the logical elements 20R3, 3AND4 and inverter 5, buses of phase commutation regimes U1-U6, the first 6.1-6.4 and the second 7.1-7.4 power amplifier groups, the first source of positive polarity +V1 for the supply of the first group power amplifiers, the second source of negative polarity -V2 for supply of the second group power amplifiers, the logical elements NOT 8.1-8.4 and the logical elements 2AND 9.1-9.4.

The device operates as follows.

For control of step motor its first, second and third phase windings are connected to the joint outputs of the first, second and fourth power amplifiers of the first and second group respectively, i.e. to the midpoints of the first, second and fourth half-bridges (the third half-bridge is not utilized).

For control of four-phase step motor its first, second, third and fourth phase windings are connected to the joint outputs of the first, second, third and fourth power amplifiers of the first and second groups respectively, i.e. to the midpoints of the first, second, third and fourth half-bridges (in this case all four half-bridges are utilized).

The device is prepared for control regimes of three-phase step motor by applying of the single logical potential to U5 bus. The single potential is applied to the third input of the 3AND4 element, which allows to carry out its automatic transition to the reset zero position after setting of the second and third stages of counter 2 into a single position. Owing to this it becomes possible to provide for the K_p=6 scaling ratio for both direct and reverse working orders of the counter 2. The preparation of the device for control regimes of the four-phase step motor is carried out by applying the zero logical potential to U5 bus. The element 3AND4 is locked at its inputs, and a permanent zero logical potential appears on its output. In the result of it permanent zero potential is maintained on the V input of the counter 2 parallel information recording, which allows to function as a common binary three-digit counter with K_p=8 scaling ratio.

Before creation of each of phase commutation regimes of three-phase and four-phase step motors, the binary counter 2 on the R input is set into zero reset/initial position. Depending on needed rotation direction of the motor to the DIR bus of the counter 2 zero or single logical stage of the potential is applied. The setting of a certain regime of three- and four-phase phase commutation is carried out by applying the required combination of zero and single logical stages of the potential to the buses U1-U6 (tables 1-8).

Under any of possible phase commutation regimes of three-phase or four- phase step motors the tact-by-tact receipt of the impulses to the C bus leads to a certain switching of the discharge outputs of the counter 2 and respective address inputs of the multiplexers 1.1-1.4. Owing to it alternating potential transfer takes place, that are present at their information inputs, to the control inputs of the corresponding power amplifiers 1.1-1.4, 2.1-2.4 and respective switchings. This creates certain cyclograms of the step motors phase commutation.

The regimes of unipolar commutation of three-phase (Figure 2 and Table 1) and four-phase (Figure 5 and Table 5) step motors are created by applying "0" potential level to U6 bus of phase commutation regime setting. The elements 2AND 9.1-9.4 are locked at their inputs, whereas their output zero potentials lock (switch off) the power amplifiers of the second group 7.1-7.4 respectively. It results in operation of four power amplifiers of the first group 6.1-6.4 through only one (+V1 ) of the power supplies of the power unit and consequently to the flowing of phase currents through the motor windings in one direction.

Unipolar phase commutation regimes are possible only upon switching on of the phases of both three-phase and four-phase step motors to the power amplifiers in the form of "star" with zero common point (Figures 2 and 5, and Tables 1 and 5).

By the same phase switching scheme (but under other control potentials on U1-U6 buses) bipolar motor phase commutation regimes are possible as well (Figure 2 and Table 2, Figure 5 and Table 6). They are created by applying the "1st" logical potential to U6 bus. Owing to it both groups of power amplifiers and both power supplies of the power unit (+V1 and -V2) take part in the process of formation of bipolar phase commutation regimes.

Bipolar phase commutation regimes of three-phase and four-phase step motors are ensured with the help of the presented device through connection of the phases to the power amplifiers through "star" scheme without common zero point as well (Figure 3 and Table 3, Figure 6 and Table 7) and through "Triangle" (Figure 4 and Table 4) and "quadrangle" (Figure 7 and Table 8) schemes.

The peculiarities of the last two groups of bipolar phase commutation regimes lie in the fact that the motor commutated phases are under the total voltage of both power supplies of the power unit +V1 and -V2. This results in respective increase of phase currents and consequently of the absolute values of the vectors of the net moments. In order to avoid the nominal permissible phase currents under these regimes, the voltage values of power supplies of power unit +V1 and -V2 must be respectively decreased, or on eof them has to be switched off, and its corresponding power line has to connected to the common zero bus of the device.

In connection with the fact that control inputs of multiplexers 1.1-1.4 are controlled from the outputs of the second and third discharges of counter 2, and their certain information inputs through element 2OR3 are connected to output of the first discharge of counter 2, switching of their outputs and respectively power amplifiers and motor windings under 6 and 8 tact phase commutation regimes takes place during each tact of impulse receipt in the C input of counter 2, under 3 and 4 tact regimes it takes place every other tact. This allows to keep the average speed of the motor drive at transition from any regime to any other regime of phase commutation. Reversible orders of phase switchings of step motors are ensured in the same way directly as described above. The reversing is carried out by changing recount direction of the counter 2 (with the help of changing of the logical potential to its opposite on DIR bus).

Thus, the presented device for programmed control of three-phase and four-phase step motors has wide functional potential and profitably differs from analogues, as it ensures 32 in total various phase commutation regimes, i.e. 12 regimes for three-phase step motor (3 unipolar and 3 bipolar under phase switching of "star" scheme with common zero point, 3 bipolar regimes under "star" scheme without common zero point and 3 bipolar regimes under "triangle" scheme) and 20 regimes for four-phase step motor (5 unipolar and 5 bipolar under phase switching of "star" scheme with common zero point, 5 bipolar regimes under "star" scheme without common zero point, 5 bipolar regimes under "quadrangle" scheme).

Information Sources

1. B.LLI. ApyTiOHHH, A.3. MypaAHH, CO. IviKpT^aH H M.X. AKOIMH. NCTpoHCTBO AΛH MHOΓOPΘJKHMHOIΌ yπpaBΛeHHa m-φa3Hκπγr iπaroBBiM 3ΛeκτpoABHraτeΛθM. A.C. CCCP 1083321, H02P 8/00 B.H.12, 1984r.

2. B.LLL Apyτκ)H5iH H A.3. MypaA#H. YCTPOHCTBO ,-yυι πporpaMMHoro ynpaBΛΘHH5i πiaroB i ABHraTeΛβM. A.C. CCCP 1352463, G05B 19/40, B.H.42, 1987r.

Claims

A device for programmed control of three-phase and four-phase step motors, which contains the first, second, third and fourth multiplexers with two control and four information inputs, a binary three-digit impulse counter with tacting, reset, reversible, admit and parallel information recording inputs, logical elements 20R, 3AND and an inverter, the first, second, third, fourth and fifth buses of phase commutation setting regimes, the second, third, fourth and first information inputs of the respective first, second, third and fourth multiplexers are connected to the second information parallel recording input of the counter and to the common zero bus of power supplies, the fourth, first, second and third information inputs of the respective first, second, third and fourth multiplexers are connected to the first bus of phase commutation regime setting, the first, second and fourth information inputs of respective first, second and fourth multiplexers are connected to the second bus of phase commutation regime setting, the third information input of the third multiplexer is connected to the third bus of phase commutation regime, the third, fourth, first and second information inputs of the respective first, second, third and fourth multiplexers are connected to the output of element 20R, the first input of which is connected to the fourth bus of phase commutation regime setting, and the second input is connected to the output of the counter first discharge, the first and second control inputs of all multiplexers are connected to the outputs of the second and third counter discharges respectively and, simultaneously, to the first and second inputs of element 3AND, the third input of which is connected to the fifth bus of phase commutation regime setting, and the output is connected to the parallel information recording input of the counter, the inverter input is connected to the reversible output of the counter, and the output is connected to its first and third inputs of information parallel recording, wherein because of additional first and second groups of four amplifiers, connected to each other respectively and forming a half-bridge of step motor phase commutation for each canal, the first source of positive polarity for supply of the first group power amplifiers, the second source of negative polarity for supply of the second group power amplifiers, a group consisting of four logical elements NOT, a group consisting of four logical elements 2AND and the sixth bus of phase commutation regime setting, each canal of motor control the multipexer output being connected to the control input of the first group power amplifiers of the given canal and simultaneously to the NOT element input, the first input of element 2AND of each canal is connected to the output of element NOT of the given control canal, the second input is connected to the additionally introduced sixth bus of phase commutation regime setting, and the output is connected to the control input of the second group power amplifiers of the given canal.