JPH0467439B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a method for driving a pentagon jumper of a five-phase stepping motor. (Prior art) As a driving method for a 5-phase stepping motor, which consists of a stator wound with five excitation windings (hereinafter referred to as windings) and a rotor equipped with permanent magnet poles, a conventional pentagon chopper drive is used. method is used. As shown in Fig. 1, this driving method connects the ends of five windings 1 and 2, connects the beginnings of windings 2 and 3 indicated by "●", and connects the ends of windings 3 and 4. Connect the ends of windings 4 and 5, connect the ends of winding 5 and the beginning of winding 1, and connect the windings 1, 2, 3, 4. , 5 are connected in series in the order of pentagons. and these windings as 10
Using the transistor switching elements T _r1 to _{T r10} , an excitation current having one cycle of a to j in Fig. 3 is passed through each winding for each excitation step under the excitation sequence shown in Fig. 2. It is used for driving. That is, when rotating the rotor in the CW direction of FIG. 2, firstly, as shown in FIG. 1, the switching element T _r9 whose emitter is connected to the positive terminal of the power supply V,
By turning on T _r7 and T _r3 and turning on the switches T _r2 and T _r6 whose collectors are connected to the negative terminal of the power supply V, the point "○" shown in Figure 3a is set to a potential (point of inflow of excitation current). , a current is caused to flow in the direction of the arrow in the figure through the four windings 2, 3, 4, and 5 with the point "●" at a negative potential (the outflow point of the excitation current). Next, the switching element
T _r9 , T _r3 , T _r8 , T _r6 , and T _r2 are turned on to flow current in the direction of the arrow in FIG. 3b through the four windings 1, 3, 4, and 5. Next, windings 1, 2, 4, and 5 receive current in the direction of the arrow shown in Figure 3 c, and windings 1, 2, 3, and 5 receive current in the direction of the arrow shown in Figure 3 d.
A current is passed in the direction of the arrow, as shown in Figure 3 e → q →...
After passing the current in the order shown in Figure 1, the switches T _r7 , T _r3 , T _r10 , T _r6 , and T _r2 are turned on, and the third switch is turned on.
The current in the direction of the arrow shown in Figure J is passed through the four windings 1, 2,
It is driven by determining the order of excitation to be applied to 3 and 4.
Table 1 summarizes the potential relationships at the current inflow and outflow points A, B, C, D, and E.

[Table] In this pentagon drive system, 4 of the 5 phases are always
Maximum output is always produced because it is four-phase excitation, that is, 4-4φ full-step excitation, in which current flows through the phase windings. Moreover, as shown in Figure 3, the current inflow point (point "○" in the diagram) or current outflow point (point "●" in the diagram) is always located at both ends of a different one of the five phases for each excitation step. will be located. Therefore, for example, as shown in FIG. 3a, in the winding 1 indicated by an "X" where the current inflow points are made at both ends, the switching elements T _r7 and T _r9 are turned on, and the winding 1 is short-circuited or the third When a current outflow point is created as shown in FIG. b, both ends of the winding 2 are short-circuited, and the windings 1, 2, 3, 4, and 5 are short-circuited in this order in one cycle. For this reason, due to the short circuit of the induced voltage generated in the windings at this time, a current flows in a direction to control the rotor, thereby performing well-known dynamic braking. Therefore, there is an excellent advantage of applying excellent damping to the rotor and effectively eliminating resonance phenomena without performing feedback control. In addition to this, in the case of other drive systems, such as the standard drive system, the control transistor switching element is the fourth
As shown in the figure, 20 pieces are required in principle, but
As shown in Fig. 1, an excellent advantage in terms of the circuit configuration can be obtained by requiring only 10 parts, which is 1/2. (Problems with the prior art) On the other hand, as mentioned above, even though the power supply has five input/output points, in each excitation step, both ends of the windings of different phases are always set to the same potential and short-circuited. 4-4φ
It has the disadvantage that it is limited to excitation and cannot perform so-called 4-5φ excitation for half excitation as in the standard method, for example. In addition, when such a driving method is adopted, for example, as shown in a in Fig. 3, there are points where current for two phases flows (A, B in the figure,
E) and points (C and D in the figure) where only one phase's worth of current flows, and points where two or one phase's worth of current flows one after another during the excitation process as shown in Figure 3 a to j. and changes. For this reason, the configuration of the control circuit becomes complicated and at the same time it requires a large power supply capacity, which is economically disadvantageous compared to other drive systems. In addition, if we look at the changes in potential at the current inflow and outflow points along the excitation sequence, we can see that the control transistor switching element detects the sudden change in potential of H-L-H-L during the off-time as shown in Table 1 above. The transistors are used under harsh conditions because they are subjected to frequent repeated exposures without any damage. Therefore, it is necessary to take measures to avoid damage to the transistors, which, together with the complication of the circuit for supplying the current, significantly complicates the circuit configuration. For this reason, although it is clear that this drive method is superior to other drive methods depending on the conditions of use, it is currently hardly put into practical use. The present invention has been made to further alleviate the various drawbacks of the pentagon drive system as described above. (Means and effects of the present invention for solving the problems) The present invention provides that the polarity of the current flowing through each phase connected to the pentagon and the windings that are shorted are the same as in the conventional system at each excitation step, In addition, the connections of the five windings, the current inflow points, and the current outflow points are selected so that the windings through which the current flows are always two sets connected in series for two phases, and the various aspects of the pentagon drive method described above are selected. This is an attempt to make the shortcomings even worse. That is, as is clear from the comparison diagram of the conventional system and the connection of the present invention in the 4-4φ excitation system shown in FIG. → Connected in the order of 4 → 5, and windings 1 and 2 are connected at the end of each winding (points other than the "●" points in the diagram), 2,
3 and 4 are connected in series with each other at the beginning of the winding (point "●" in the figure), 3 and 4 are connected in series with each other at the end of the winding, 4 and 5 are the beginnings of each winding, and 5 and 1 are connected in series between the beginning and the end of the winding. On the other hand, in the present invention, the windings are changed from 2→4→1→3→5 or 1→3→5→
Connect in the order of 2 → 4, and windings 2 and 4 are the beginning and end of winding, 4 and 1 are the beginnings of winding, 1 and 3 are the end of winding and the beginning of winding, 3 and 5 are the end of winding and the beginning of winding, The winding ends of windings 5 and 2 are connected in series and pentagonally connected, and current inflow and outflow points are provided at each connection point of the excitation winding, and these current inflow and outflow points are shown in Table 2 during the excitation step operation. As shown, it is driven in the basic sequence in which a continuous 3-step current flows in (H in Table 2), then a 2-step pause, and then a continuous 3-step current flows out (L in Table 2), and the excitation step is changed to the excitation winding. While wires 1, 2, 3, 4, and 5 were short-circuited in the order, the excitation windings through which the excitation current was passed became two sets connected in series for two phases at each excitation step stage, and the wires were short-circuited. The feature is that the current inflow point "○" and the current outflow point "●" are selected by controlling the switching elements on and off so that the excitation current of the required polarity for rotation flows through the excitation windings other than the excitation winding. That is. That is, as shown in Figure 6a, the current inflow point is set to point C.
By selecting the outflow points at points A and E, current is passed through the series circuit of windings 5 and 3 and the series circuit of windings 2 and 4, and the third A current of the same polarity as the conventional method shown in figure a is passed,
Both ends of the winding 1 are set to the same negative potential and short-circuited (marked with an x in the figure). Next, as shown in Figure 6b, by selecting points C and D for current inflow and point A for outflow, currents of the same polarity as in Figure 3b, which shows the conventional method, flow through each winding. At the same time, the winding 2 is short-circuited (marked with an x in the figure). By selecting the current inflow and outflow points as shown in Fig. 6 c to j below, the current corresponding to the conventional method shown in Fig. 3 a to j is applied to each phase for driving. . (Effects of the Invention) As described above, in the present invention, the number of current inflow and outflow points is three, compared to five in the conventional system, so the control circuit is simplified accordingly. Also definitely 2
Current is commonly passed through a circuit in which two phases are connected in series, and the current for two phases does not flow in or out at a certain point or for one phase at a certain point, as in the conventional case. Therefore, not only is the current balance improved, but the current capacity is halved, and efficiency can be increased and heat generation can be reduced by reducing transistor loss. Moreover, in the present invention, since a short circuit phase is provided for each excitation step as in the prior art, it is possible to effectively damp the rotor and suppress the resonance phenomenon. In addition, in the present invention, since the windings are connected in series, it is likely that this will have a negative effect on the rise of the current and make it impossible to rotate at high speed compared to conventional drive methods. Since the new phase connected in series is excited by the back electromotive force generated when switching the excitation of the phase that is on, this method is equivalent to or superior to the conventional method. That is, in the present invention, for example, when the E point is turned off in the steps from a to b in FIG. Therefore, the start-up will not deteriorate. In addition, the back electromotive force from the coil of winding 2 that is turned off also acts additively on winding 4, and at the same time
The short-circuit current of acts on the rotor to show an optimal braking effect. Further, in the step from b to c in Fig. 6, point C is turned off, and the back electromotive force generated thereby is directly applied to winding 2, and the back electromotive force generated in winding 3, which is turned off at this time, is also applied to winding 2. At the same time as acting additively on wire 5, the short-circuit current in winding 3 acts with optimal effect on the rotor. Therefore, the rise of the current is equal to or higher than that of the conventional one, and the damping effect based on the shorted phase is improved, so that the occurrence of resonance phenomenon can be effectively prevented. Furthermore, in the present invention, the potential changes at each point A, B, C, D, and E in each step of FIG. The situation is as shown in Table 2.
For example, when looking at the potential change at point A,

[Table] Steps a, b, and c in Fig. 6 are at L level, that is, current flows out, steps d and e in Fig. 6 are OFF, that is, current inflow and outflow are stopped, f,
At each point B, C, D, and E, the L and H levels are set so that the current flows at H level at points g and h, and is off at steps i and j in Fig. 5.
There is always an off period in between. Therefore, unlike the conventional method, the transistor switching elements at each point are not forced to operate harshly, and as a result, there is no need for a protection circuit for the transistor switching elements. Simplified. Therefore, obstacles to practical application due to circuit complexity are eliminated. In addition, although we have explained 4-4φ excitation above,
According to the present invention, 4-5φ excitation is possible and half drive can be performed. In other words, when the current flows from the end of the winding to the start of the winding, it is + (plus), and when the current flows from the beginning of the winding to the end of the winding, it is - (minus).
When the windings that generate torque are shown as 1, 3, 5, 2, and 4, the initial current inflow and outflow points are set at point C, as in Fig. 7a, which shows 4-4φ excitation, as in Fig. 6, which shows 4-4φ excitation.
If A and E are selected, a becomes (+2) (+3) (+
4) (+5), and the torque acts additively. Next, as shown in Figure _7a1 , by selecting the current inflow point as point C and the current outflow point as point A, a series circuit of windings 5 and 3 and a series circuit of windings 2, 4 and 1 are formed. If current with the required excitation polarity is passed through all five phases,
a ₁ becomes (+2) (+3) (+4) (+5) (-1), and the torque acts additively. Next, as shown in Fig. 7b, if current flows through the four phases other than short-circuited phase 2 at the current inflow and outflow points as in Fig. 6b, Fig. 7b becomes (+3) (+
4) (+5) (-1), and the torque acts additively. Next, as shown in Figure _7b1 , the current inflow and outflow points are D,
A is selected and windings 2, 5, 3 are connected in series with winding 4,
If a series circuit of 1 is formed and current flows through all 5 phases,
b ₁ becomes (+3) (+4) (+5) (-1) (-2), and the torque acts additively, and from Figure 7 c below, c is (+4) (+5) (-1). (-2), c ₁ is (+4) (+5) (-1) (-2) (-3), d is (+
5) (-1) (-2) (-3), d ₁ is (+5) (-1)
(-2) (-3) (-4), e is (-1) (-2) (-
3) (-4), e ₁ is (-1) (-2) (-3) (-4)
(-5), and by arranging the five-phase winding as shown in FIG. 5b, it is possible to flow currents of each required polarity in the order of 4φ→5φ→4φ→5φ, which always adds torque. Therefore, half drive can be realized by enabling 4-5φ excitation. Also, the potential changes at the current inflow and outflow points at this time are as shown in Table 3, and 4-
Similar to 4φ excitation, there is always an off time between H level and L level, so a protection circuit for the transistor is not required. Therefore, it is possible to realize a practical bipolar pentagon chopper driving method that eliminates the various drawbacks of the conventional method.

【table】 [Brief explanation of the drawing]

Figures 1, 2, 3 a to 4, and 4 are explanatory diagrams of the conventional system, of which Figure 1 is a winding connection diagram, Figure 2 is an excitation sequence diagram, and Figure 3 is an excitation sequence diagram. is an excitation state diagram for each step, and FIG. 4 is a standard type switch circuit diagram. Figures 5a and b are comparison diagrams of winding connections in the conventional and the present invention, Figures 6a to j are excitation state diagrams for each step in 4-4φ excitation, and Figure 7 is diagrams for each step in 4-5φ excitation. FIG. 1, 2, 3, 4, 5...Winding, T _r1 ~ _{T r10} ...
Control transistor switching element, A, B,
C, D, E... Current inflow or outflow points.

Claims (1)

[Claims] 1. While short-circuiting the excitation windings in the order of 1, 2, 3, 4, and 5, an excitation current of the required polarity necessary for rotation is caused to flow through the excitation windings of the other four phases. I made it to 5
In the pentagonal stepper driving method of a phase stepping motor, the beginning of the excitation winding 2 and the end of the excitation winding 4 are connected to each other, the beginnings of the excitation windings 4 and 1 are connected to each other, and the excitation winding is connected to the end of the excitation winding 4. Connect the end of wire 1 and the beginning of excitation winding 3, connect the end of excitation winding 3 and the beginning of excitation winding 5, and connect the ends of excitation windings 5 and 2 to each other. Connect the excitation windings 2, 3,
Connect the Pentagon in the order of 1, 4, 5, and
A current inflow and outflow point is provided at each connection point of the excitation winding, and this current inflow and outflow point is continuous three times during excitation step operation.
It is driven in a basic sequence in which a step current flows in, then pauses for 2 steps, and then 3 consecutive step currents flow out. At each excitation step stage, the excitation windings through which current flows are connected in series into two sets for two phases, and the excitation windings other than the short-circuited excitation windings are supplied with an excitation current of the required polarity for rotation. A method for driving a pentagon chopper of a five-phase stepping motor, characterized in that 4-4 phase excitation is performed by selecting an inflow point and an outflow point of an excitation current in each excitation step so that the excitation current flows respectively.