EA003109B1 - Device for multimode control of a three-phase stepping motor - Google Patents

Abstract

A device for multimode control a three-phase stepper motor, comprising a first and a second power sources of the power part with opposite polarities, a power source of the logic part, a four-stage binary reversible impulse counter with input leads of clocking, reversing and setting to the initial state, a first group of three multiplexers connected by their terminals to the control inputs of the first group power amplifiers, commuting phase windings of the stepper motor via the power source of the positive polarity, a second group of three multiplexers connected by their terminals to the control inputs of the second group power amplifiers, commuting phase windings of the stepper motor via the power source of the negative polarity, a first and a second gating leads connected respectively to the first and the second groups of multiplexers, the control inputs of which are connected respectively to the inputs to the third and the fourth stages of the binary counter, the phase windings of the stepper motor are connected to the middle point of the respective power amplifiers of the first and the second groups, forming in couples half-bridges, an AND-NOT element, the output of which is connected to the first, second and third information inputs of respectively first, second and third multiplexers of the first group, the second, third and first information inputs of which are connected to the common zero lead of the device power sources, an OR-NOR logic element of which is connected to the third, first and second information inputs of respectively first, second and third multiplexers of the second group, the first, second and third information inputs of which are connected to the common zero lead of the device power sources, characterized in that the device further comprises 2AND-2AND-OR first and second logic elements and four leads of the device operation mode, wherein first inputs of the 2AND first elements of the 2AND-2AND-OR first and second elements are connected to the power lead of the device logic elements, and the second inputs respectively to the first and second leads of the mode assignment, the first inputs of the 2AND second elements of the 2AND-2AND-OR first and second elements are connected respectively to the outputs of the counter first and second stages, and second inputs respectively to the third and fourth leads of the mode assignment, the output of the 2AND-2AND-OR first element is connected to the first inputs of AND-NOT and OR-NOT elements, and the output of the 2AND-2AND-OR second element is connected to the second inputs of the AND-NOT, OR-NOT elements and simultaneously to the third, first and second information inputs of respectively first, second and third multiplexers of the first group.

Description

The invention relates to the field of automation and electrical engineering and can be used to control three-phase stepper motors with active, passive and hybrid rotors in the electric drives of the actuators of robots, computer-controlled machines and peripherals of computers.

A device for controlling a stepper motor is known, which comprises three multiplexers, three power amplifiers, a control signal source, a reversible binary pulse counter, a 2OR gate, and a bus for setting the motor phase switching mode when controlling a three-phase stepper motor [1].

The disadvantage of this device is the limited functionality, which consists in providing only unipolar switching modes of the phases of the stepper motor.

The closest in technical essence to the proposed one is a device for controlling a stepper motor, containing the first and second power sources of the power part with opposite polarities, the power supply of the logical part, a four-digit reversible binary pulse counter with input buses for reversing, clocking and resetting, the first group of three multiplexers connected by their outputs to the control inputs of the power amplifiers of the first group, commuting the phase windings of a step motor through a power supply of positive polarity, a second group of three multiplexers connected by their outputs to the control inputs of power amplifiers of the second group, commuting the phase windings of the stepper motor through a power supply of negative polarity, the first and second gate buses connected respectively to the gate inputs of the first and second groups of multiplexers, the control inputs of which are connected respectively with the outputs of the third and fourth digits of the binary counter. In it, the phase windings of the stepper motor are connected to the midpoints of the connection of the corresponding pairs of power amplifiers of the first and second groups, which form half-bridges in pairs. In addition, this device contains an AND-NOT logic element, the output of which is connected to the first, second, and third information inputs of the first, second, and third multiplexers of the first group, the second, third, and first information inputs of which are connected to the zero bus of the device’s power sources, the logical an OR-NOT element, the output of which is connected to the third, first and second information inputs, respectively, of the first, second and third multiplexers of the second group, the first, second and third information inputs which are connected to the common zero bus power sources of the device [2].

The disadvantages of this device are low reliability, low tech when manufacturing in the form of a monolithic microcircuit of medium or large integration, narrow operational capabilities when working from a computer or from any logical control unit. These disadvantages are due to the use of two three-position mechanical switches in it for setting and changing the switching modes of the phases of the stepper motor.

The aim of the invention is to increase reliability, increase manufacturability and expand the operational capabilities of the device.

This goal is achieved by the fact that in the device for multi-mode control of a three-phase stepper motor, the first and second logical elements 2I-2I-OR and four buses for setting the operating mode of the device are additionally introduced. Moreover, the first inputs of the first elements 2I of the first and second elements 2I-2I-OR are connected to the power supply bus of the source of logical elements of the device, and the second inputs are respectively the first and second buses of the mode setting, the first inputs of the second elements 2I of the first and second elements 2I-2I OR are connected respectively with the outputs of the first and second bits of the counter, and the second inputs are respectively with the third and fourth buses of the mode setting. The output of the first element 2I-2I-OR is connected to the first inputs of the elements AND-NOT and OR-NOT, the output of the second element 2I-2I-OR is connected to the second inputs of the elements AND-NOT and OR-NOT and simultaneously with the third, first and second information the inputs, respectively, of the first, second and third multiplexers of the first group.

In FIG. 1 shows a structural diagram of the proposed device for multi-mode control of a three-phase stepper motor; in FIG. 2-5 are diagrams of the connection of the phases of the engine to power amplifiers, respectively, in the form of a star with zero and without a zero common point, as well as in the form of a triangle, the corresponding nomograms of the electrical positions of the vectors of the resulting engine moments, the control table and the phase switching modes.

The device contains (Fig. 1) the first + V1 and second-V2 power sources of the power part with opposite polarities, the power supply Uss of the logical part of the device, the first and second groups of power amplifiers 1.11.3 and 2.2-2.3, the first and second groups of multiplexers 3.1- 3.3 and 4.1-4.3, with the corresponding gating buses Ep1 and Ep2, a four-bit binary counter counter 5 with the conversion module Кп = 12, the logical element INE6, the logical element OR-NOT7, the first and second logic elements 2I-2I-OR8,9 and Bus control mode switching phases U1U4.

The device operates as follows.

Before creating each of the possible switching modes for the phases of a three-phase stepper motor, the binary counter 5 at the input I is set to the initial zero logical state.

Depending on the required direction of rotation of the engine, a zero or one logical potential level is applied to the EHN bus of the counter 5. Depending on the required phase switching mode, the corresponding logical levels of potentials are applied to the busbars for setting the U1-U4 mode and to the gating buses Ep1 and Ep2 (see Table 1-4).

Unipolar phase switching modes (Fig. 1, 2) are created by applying 1 potential level to the gating bus of one of the multiplexer groups and 0 potential level to the gating bus of another group of multiplexers. At the same time, at the outputs of those multiplexers, to the gating inputs of which 1 potentials are applied, zero potentials arise, which support the corresponding three power amplifiers in permanently locked (disconnected) states. This leads to the operation of the remaining three power amplifiers from only one of the power sources of the power unit and, as a result, to the flow of phase currents through the motor control windings in only one direction. Modes and sequence of phase switching during unipolar control is created, as can be seen from table. 1, depending on the corresponding logical potential levels applied to the control buses U1-U4 and Ep1, Ep2.

Unipolar phase switching modes are possible only when the phases are turned on to power amplifiers according to the star scheme with zero common point (Fig. 2).

According to the same switching scheme (but with other control potentials on the U1U4 tires), bipolar modes of switching the motor phases are also possible (Fig. 3 and Table 2). They are created by applying zero potentials to both gate buses Ep1 and Ep2 of the multiplexers.

Due to this, all multiplexers, as well as all power amplifiers of both groups and both power sources of the power unit take part in the formation of bipolar phase switching modes (Fig. 3, Table 2).

Bipolar modes of switching the phases of the motor are provided by the proposed device also when connecting the phases according to the star scheme without a zero common point (Fig. 4 and Table 3) and according to the triangle scheme (Fig. 5, Table 4).

The features of the last two groups of bipolar modes are that the switched phases of the motor are under the combined voltage of both power sources of the power unit + U1 and -U2. This leads to a corresponding increase in phase currents and, therefore, modules of the resulting moments (see nomograms in Figs. 4 and 5). In order to avoid an increase in the nominally permissible phase currents under these conditions, the voltage values of the power sources of the power unit + V1 and V2 must be reduced accordingly or one of them must be disconnected, and the corresponding power bus must be connected to the common zero bus of the device. Due to the fact that multiplexers 3 and 4 are controlled from the 3rd and 4th digits of counter 5, and their specific information inputs are connected via logic elements 69 to constant (zero or single) potential levels or to the outputs of the 1st and 2 bits of the same counter 5, then the change of their output potentials and the corresponding switching of power amplifiers and phase windings of the motor in 12-cycle switching modes occur when each clock pulse arrives at the input T of counter 5, in 6-cycle modes - through one pulse , and in 3 ktny modes - through three impulses. In each of these operating modes of the device, after 12 clock cycles, counter 5 is automatically reset to zero due to its internal logical structure.

Reverse phase switching orders of the stepper motor are provided similarly. Reversal is carried out by changing the direction of conversion by the counter 5 (with the help of a change in potential on its bus Е1Я).

Thus, the proposed device for multi-mode control of a three-phase stepper motor compares favorably with known similar devices in that it provides a total of 27 different phase switching modes (6 unipolar and 7 bipolar - when the phases are turned on according to the star scheme with a common zero point, 7 bipolar - according to the star scheme without a common zero point and 7 bipolar - according to the triangle scheme).

In addition, it has high reliability, high manufacturability and wide operational capabilities.

Claims (1)

CLAIM A device for multi-mode control of a three-phase stepper motor, containing the first and second power supplies of the power part with opposite polarities, the power supply of the logical part, a four-digit reversible binary pulse counter with input clock, reverse and initialization buses, the first group of three multiplexers connected by their outputs with control inputs of the power amplifiers of the first group, commuting the phase windings of the stepper motor through a power source of positive polarity, the second group of three multiplexers connected by their outputs to the control inputs of the power amplifiers of the second group, commuting the phase windings of the stepper motor through a negative polarity power supply, the first and second gating buses connected respectively to the gate inputs of the first and second groups of multiplexers, control inputs which are connected respectively to the outputs of the third and fourth bits of the binary counter, the phase windings of the stepper motor are connected to the midpoints of the connection of the respective power amplifiers of the first and second groups, forming pairwise half-bridges, an NAND element, the output of which is connected to the first, second and third information inputs, respectively, of the first, Table 1 of the second and third multiplexers of the first group, the second, third and first information inputs of which are connected to the common zero bus of the device’s power sources, the OR-NOT logic element, the output of which is connected to the third, first and second information inputs of the first, second and third multiplexers, respectively the second group, the first, second and third information inputs of which are connected to the common zero bus of the device power sources, characterized in that it additionally contains the first and second logic 2I2I-OR elements and four buses for setting the device operation mode, with the first inputs of the first 2I elements of the first and second 2I-2IIIL elements connected to the power supply bus of the device logic elements, and the second inputs respectively to the first and second mode setting buses, the first inputs of the second elements 2I of the first and second elements 2I-2I-OR are connected respectively to the outputs of the first and second bits of the counter, and the second inputs are respectively the third and fourth buses of the mode, the output of the first element 2I2I-OR is connected to the first the moves of the AND-NOT and OR-NOT elements, and the output of the second 2I-2I-OR element is connected to the second inputs of the AND-NOT, OR-NOT elements and simultaneously with the third, first and second information inputs of the first, second and third multiplexers of the first group, respectively .