JP3170838B2 - Drive device for variable reluctance motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable reluctance motor driving apparatus.

[0002]

2. Description of the Related Art Variable reluctance motors (hereinafter referred to as SR motors) have the advantage that a large torque can be obtained because the stator and rotor are made of iron and the magnetic flux density can be increased. However, it is difficult to rapidly increase or decrease the exciting current. In particular, since the output characteristic (rotational speed-torque characteristic) at the time of high-speed rotation is not excellent, it is often used as a motor for medium- and low-speed rotation without being adopted for high-speed rotation.

In the SR motor having such features, each phase winding is energized by a driving device from a DC power supply circuit in a predetermined circulation order and is driven to rotate. When the energization is interrupted, the phase winding has a magnetic energy [J] of 1/2 × H × i2 (i: phase winding current at the moment of stop of energization, H: inductance of the phase winding). Has been accumulated. In order to quickly recover this magnetic energy and prevent the generation of negative torque with respect to the rotation of the SR motor, the drive device is provided with a regenerative / electric storage circuit that regenerates the magnetic energy as electric charge and stores it in a capacitor.

For example, as shown in column (A) of FIG. 8, the main components are energization control circuits 110a, 110b, and 110c for controlling energization from the DC power supply 102 to the phase windings La, Lb, and Lc. Drive device 100 for three-phase SR motor
It has been known. In this type of driving device 100,
The rotor is continuously rotated by energizing the phase windings La to Lc in a predetermined circulation order to excite the corresponding magnetic poles (not shown) of the stator. For example, in the order of A phase → B phase → C phase → A phase, two transistors (11
2a / 114a), (112b / 114b), (112
The drive device 100 rotates the SR motor by sequentially turning on and off c.114c) at the same time. Each of the transistors (112a and 114a) to (112c
When 114c) is turned off, the magnetic energy accumulated in the excited phase windings La to Lc is used as electric charges as commutation diodes (116a and 118a) and (116b and 1).
18b), DC power supply 1 via (116c / 118c)
02, the regenerative charge is supplied to the phase windings La to Lc to be energized next, thereby suppressing the generation of negative torque and reducing power loss. In this case, a capacitor having a large capacity is adopted so that an overvoltage does not occur when power is cut off.

As shown in FIG. 8B, a drive device 200 for a three-phase SR motor employing a step-down chopper circuit 210 is also known. By preventing the overvoltage from being applied to the capacitor 204 and the regenerative capacitor 212, a capacitor having a relatively small capacity can be adopted.

In this driving device 200, when the energizing transistors 214a, 214b, 214c are turned off,
The magnetic energy stored in the phase windings La to Lb is stored as charge in the regenerative capacitor 212 via the commutating diodes 216a, 216b, 216c. As a result, the voltage of the regenerative capacitor 212 increases. When the voltage exceeds a predetermined limit voltage, the switching transistor 220 is turned on by a command from the chopper control circuit 218.
Then, current flows from the regenerative capacitor 212 to the power supply side capacitor 204 via the DC reactor 222. When current flows and the voltage of the regenerative capacitor 212 falls below the limit voltage, the switching transistor 220 turns off.
By this step-down chopper operation, the regenerative capacitor 212
Is kept constant and the regenerative capacitor 212
Magnetic energy that cannot be absorbed by the DC reactor 222
To prevent overvoltage of the power supply side capacitor 204.

[0007]

However, in the former driving device 100, two transistors (112a and 114a) to (114a and 114c) and commutation diodes (116a and 118a) to (116c and
118c), the number of elements increases, and the device becomes large and complicated. Also, the number of wires is large because the number of lead wires from the phase windings La to Lc of the SR motor to the drive device 100 is a multiple of the phase. And the number of connection terminals increases.

In the latter driving device 200, the number of switching elements and commutation diodes is halved compared to the former, but a step-down chopper circuit 210 is required.
There is a problem that the circuit configuration becomes complicated. Further, as described above, the SR motor has a characteristic that the output characteristic during high-speed rotation is inferior due to the large inductance of the phase winding.

Of course, it is conceivable to improve the characteristics by increasing the DC power supply voltage, but it is necessary to use a device with a high withstand voltage, and the production cost is high, so that it cannot be easily adopted. Alternatively, when the DC power supply is a battery, such as an electric vehicle, and it is difficult to increase the voltage due to restrictions on the mounting dimensions and weight, the number of windings of the phase windings is reduced to reduce the inductance to reduce the characteristics. It can be improved. However, a larger current is required to generate the same amount of torque, and power
It is not used to improve high-speed rotation characteristics because problems such as poor torque conversion efficiency and limitations on the current capacity of the switching element and increase in the amount of current are limited. It is difficult.

It is an object of the present invention to provide a drive device for a variable reluctance motor having a simple and simple structure and excellent in high-speed rotation characteristics.

[0011]

In order to achieve the above object,
The invention according to claim 1 is a driving apparatus for a variable reluctance motor that rotates a variable reluctance motor by energizing each phase winding of the variable reluctance motor in sequence from a DC power supply circuit. phase winding mutually by star connection to and with connecting the voltage midpoint of the neutral point and the DC power supply circuit of the star connection, the s husband the star-connected phase windings of the DC power supply circuit By switching between the positive and negative electrodes and connecting them,
Of the DC power supply circuit,
Is provided with an energizing means that performs at the voltage between the negative electrode and the voltage midpoint.
It is characterized by.

The invention according to claim 2 is the invention according to claim 1.
In the variable reluctance motor driving device of
The power supply means is connected to the DC power supply connected to each of the phase windings when energized.
The polarity switching of the Minamotokai path, to characterized in that it is carried out in phase sequence
You. The invention according to claim 3 provides the variable resistor according to claim 1.
In the drive device for a lactance motor, the DC power supply circuit
Voltage of positive side voltage and negative side voltage with respect to voltage midpoint of road
Detecting means for detecting imbalance;
Is the DC power supply circuit connected to each phase winding when energized
Switching of the polarity of the voltage detected by the detection means.
Each of the above voltages will be balanced according to the imbalance.
It is characterized by performing.

[0013]

Operation and Effect of the Invention The present invention constructed as described above
The driving device according to claim 1 is a three-phase variable reluctance device.
And each phase winding is a star connection.
And the neutral point is connected to the voltage midpoint of the DC power supply circuit.
It is.

Therefore, the phase winding and the positive electrode of the DC power supply circuit
Is connected to the positive winding of the DC power supply circuit
Voltage is applied to connect the phase winding to the negative electrode of the DC power supply circuit.
If it continues, the voltage between the negative pole of the DC power supply
Pressure will be applied. And variable reluctance
In the motor, each phase winding is, for example, A phase → B phase → C phase →
By energizing in the order of A phase → B phase ...
Rotation in a predetermined direction.
Energizing means for performing energization control described above are provided on each of the phase windings.
Switch the positive or negative DC power supply circuit
Thus, current is passed through each phase winding.

In other words, according to the present invention, each phase winding is passed in phase sequence.
The variable reluctance motor
Applied to each phase winding to energize
The voltage to be applied, the voltage between the positive electrode and the voltage midpoint of the DC power supply circuit or
The voltage is switched to the voltage between the negative electrode and the voltage midpoint.

Therefore, the driving device of the present invention (claim 1)
According to the drawing from the variable reluctance motor to the drive
It is possible to reduce the number of lead wires to four (the number of phase windings is 3 + 1)
Can reduce the number of lead wires compared to conventional equipment
Can be. The energizing means includes a positive electrode of the DC power supply circuit and
It is sufficient that the negative electrode and each phase winding can be intermittently connected.
In general, a three-phase brushless motor or the like is used as an energizing means.
Uses the well-known inverter circuit used to drive
If it is used, energize each phase winding and mark when energized.
The switching of the applied voltage can be easily performed.
When the power to the phase windings is cut off, the magnetic
Energy is transferred to the DC power supply circuit side (specifically, the positive
Side or the side opposite to the power supply circuit on the negative side)
Can be

Therefore, according to the present invention, the driving device can be reduced in size.
Configuration and simplification of the configuration.
It is possible to improve the reliability of the device. Incidentally, the present invention
Then, when energizing each phase winding of the variable reluctance motor,
The voltage applied to each phase winding is the positive voltage of the DC power supply
Switching to midpoint voltage or negative-voltage midpoint voltage
From the current direction (current
Direction), but the variable reluctance motor
Excites only the stator without using a permanent magnet for the rotor.
The rotor is rotated by attracting the rotor
Since the power supply timing is the same,
The rotational torque is always the same even if the direction of current flow is reversed.
Work in the same direction, and cut off the applied voltage to each phase winding.
Adversely affects variable reluctance motor drive
Has no effect.

By the way, the energizing means energizes each phase winding.
Sometimes the voltage applied to each phase winding is
Switch to voltage between voltage midpoint or voltage between negative electrode and voltage midpoint
Is the polarity switching of the applied voltage
Is for switching the phase winding to be energized.
It is good to carry out in order according to.

That is, the energizing means is provided as described in claim 2
If configured, the flow to each phase winding of the variable reluctance motor
When the power supply state is such that
To the positive direction, and the
In a state flowing in the negative direction toward the voltage midpoint of the road to the anode
It can be switched alternately, and the variable reluctance
In each phase of the data, for example, A phase (positive direction) → B phase (negative direction)
Direction) → C phase (positive direction) → A phase (negative direction) → B phase (square)
Direction) → C phase (negative direction) → A phase (positive direction)
Will be excited.

The direction of current flow to each phase winding
Are switched alternately, the voltage in the DC power supply circuit
Power consumption and regeneration alternate between the positive and negative sides of the midpoint
The DC power supply circuit
Voltage on the positive electrode side of the voltage midpoint (the voltage between the positive electrode and the voltage midpoint)
Voltage) and the voltage on the negative electrode side of the voltage midpoint (between the negative electrode and the voltage midpoint)
Voltage), and the current flowing through each phase winding changes.
Movement can be prevented.

That is, in the present invention, the variable reluctance
Voltage applied to each phase winding when power is applied to each phase winding
Of the positive electrode-voltage midpoint voltage and the negative electrode-voltage midpoint voltage
Switching to either, but the switching frequency is positive and negative
If they differ from each other, the balance of these voltages will be lost,
The current flowing through each phase winding varies with the switching of the applied voltage
Each phase winding as described in claim 2
If the direction of power supply to the
Make sure that the voltage balance between the positive and negative
To prevent the current from flowing to each phase winding when driving the variable reluctance motor.
Constant current (and thus the torque generated in each phase)
You can do it.

The energizing means is configured as described in claim 2.
By doing so, the above effects can be obtained,
In the DC power supply circuit, the capacity on the positive side and the negative
When the capacitance on the pole side is the same,
Are different from each other, the capacitance error
Voltage difference occurs between the midpoint voltage and the negative electrode-voltage midpoint voltage
Sometimes.

In order to prevent such a problem,
As described in claim 3, the positive and negative sides of the DC power supply circuit
A detection means for detecting a voltage imbalance on the pole side is provided,
The energizing means is connected to the voltage balance detected by the detecting means.
Each phase when energized so that each voltage is balanced
Switch the polarity of the power supply circuit connected to the winding
Good.

That is, in this case, the DC power supply circuit
The capacity on the positive side and the capacity on the negative side match with respect to the midpoint of the voltage
Even if not, the voltage between the positive electrode
Match the voltage between the voltage midpoints, and
This prevents variations in the current flow caused by the lance,
The torque generated in each phase of the motor can be made constant.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is an electric circuit diagram illustrating a drive unit of a variable reluctance motor to which the present invention is applied, FIG. 2 is an explanatory diagram schematically illustrating a circuit operation of the drive unit, FIG. 3 is a block diagram of a variable reluctance motor control system, FIG. 4 is an explanatory diagram showing the structure of the variable reluctance motor.

As shown in FIG. 1, a drive unit 10 of a variable reluctance motor (hereinafter referred to as an SR motor) having a three-phase configuration (A phase, B phase and C phase) includes a power supply circuit 13 and a power supply circuit 13. Each phase winding La, Lb, Lc of SR motor SRM
And a power supply circuit 15 for interrupting power supply to the motor, and constitutes a part of an SR motor SRM control system.

The power supply circuit 13 includes two rectifier diodes D
R1, DR2 and two capacitors C1, C2 of the same capacity
And rectifies the single-phase AC to a doubled voltage of 2V. The connection midpoint between the capacitors C1 and C2 connected in series is a voltage midpoint M, and is a single-phase AC
Of the phase winding La connected to one end of the
Lc is connected to a neutral point N (described later) by a lead line ln.

The energizing circuit 15 has a six-arm bridge configuration and is the same circuit as a so-called inverter. That is, SR
Six transistors (PNP transistors TR1a, TR1) that interrupt current supply to each phase winding La-Lc of motor SRM.
1b, TR1c and NPN transistors TR2a, TR2b, T
R2c) and six commutation diodes D1a, D1b, D1 provided for regenerating electric charges from the phase windings La to Lc, respectively.
c, D2a, D2b, and D2c. In the energizing circuit 15, commutation diodes D1a to D1c provided on the PNP transistors TR1a to TR1c side and commutation diodes D2a to D2a provided on the NPN transistors TR2a to TR2c side are provided.
D2c is connected in series, and the former commutation diodes D1a to
D1c has a cathode connected to the power supply bus DCBus (+) on the positive electrode side, and the latter commutation diodes D2a to D2c have anodes connected to the power supply bus DCBus (-) on the negative electrode side.

The connection point between the transistors TR1a and TR2a is connected to one end of the phase winding La by the transistors TR1b and TR2a.
2b is connected to one end of the phase winding Lb by the transistor T
The connection point between R1c and TR2c is connected to one end of the phase winding Lc by lead lines la, lb, and lc, respectively.

Note that an inverter manufactured as a general-purpose module may be diverted as the energizing circuit 15. The energizing circuit 15 configured as described above is provided with the energizing means of the present invention.
When one of the transistors TR1a to TR2c is turned on in a predetermined circulation order, one of the phase windings La to Lc is energized. For example, TR1a → TR
2b → TR1c → TR2a → TR1b → TR2c → TR1a.
Excitation is performed in the order of A phase → B phase → C phase → A phase. When the energization period has passed and the transistors TR1a to TR2c have turned off,
The magnetic energy stored in the phase windings La to Lc is regenerated as charges in the capacitor C1 or C2 via the commutating diodes D1a to D1c or D2a to D2c. The energization and regeneration paths are performed when the PNP transistors TR1a to TR1c are switched and when the NPN transistors TR2a to TR2c are switched.
This is different from when R2c is switched.

That is, as shown in FIG.
When one of R1a to TR1c (represented by the reference symbol TR1 in the figure) is turned on, a current flows through a path from the transistor TR1 to the relevant phase winding (represented by the reference symbol L) → neutral point N, When the transistor TR1 is turned off, the phase winding L → the neutral point N → the capacitor C2 → the commutation diode D2
→ The current i in the loop of the phase winding L (indicated by the dashed line in the figure)
1 flows to charge the capacitor C2. On the other hand, when one of the transistors TR2a to TR2c (represented by the reference symbol TR2 in the figure) is turned on, a current flows through the path of the neutral point N → the relevant phase winding L → the transistor TR2, and the transistor TR2
2 turns off, the phase winding L → commutation diode D1
→ Capacitor C1 → Neutral point N → Current i2 flows in a loop of the phase winding L (indicated by a two-dot chain line in the figure) to charge the capacitor C1. That is, the transistors TR1a to TR1a
During energization / interruption by 1c, one of the capacitors C1 and C2 functions as a power supply and the other functions as a regenerative charge storage.

As described above, the NPN transistor T
At the time of switching of R2, the PNP transistor TR1
The current flows in the opposite direction to the case of. However, the SR motor SRM does not use a permanent magnet for the rotor, and also attracts the rotor by an electromagnetic force generated by exciting only the stator to rotate the rotor. Therefore, if the energization timing is the same, the rotational torque is always in the same direction even if the energization direction is different.

As shown in FIG. 3, a variable reluctance motor control system (hereinafter, simply referred to as a control system) includes a drive unit 10,
It is composed of a main controller 20 and a power supply controller 30. The main control unit 20 detects a detection signal S from a magnetic pole sensor (not shown).
Based on the detection signal idet (phase winding current value) from the MP and the current sensor CS, the speed command signal SP from the outside, etc.
The power supply cycle and power supply period (power supply timing) of the R motor SRM are determined. The energization control unit 30 selects a phase to be energized based on the energization timing signals SA, SB, SC from the main control unit 20, determines the energization polarity of the phase windings La to Lc, and performs the forward rotation sequence or the reverse rotation. Each transistor TR1a is turned on so that the phase windings La to Lc are energized in a sequence.
Switching pulses PA, PB, P on the base of ~ TR2c
C, Pa, Pb, and Pc are output to output each transistor TR1a.
To control the switching of TR2c.

The energization control section 30 executes well-known chopper control during energization to control the phase winding currents ia, ib, and ic to desired levels and adjust the magnitude of the output torque. More specifically, the duty ratio of chopping is controlled according to the deviation between the target current value and the detected phase winding current value.

The configuration of each part of the control system is well-known, so that the details are omitted. As shown in FIG. 4, the SR motor SRM operated by the control system is a well-known three-phase motor having a stator ST having a six-pole configuration and a roller RO having a four-pole configuration. The stator magnetic poles Pa1 and Pa2 form a counter electrode to form an A phase, the stator magnetic poles Pb1 and Pb2 form a counter electrode to form a B phase, and the stator magnetic poles Pc1 and Pc2 form a counter electrode.
Form a phase. In such a magnetic pole structure, in a section in which the rotor salient pole approaches the stator magnetic poles (Pa1, Pa2) to (Pc1, Pc2), the inductance of the phase windings La to Lc increases, and the rotor salient pole becomes the stator magnetic pole (Pa1).・ Pa2) ～
The inductance becomes maximum when directly facing (Pc1 · Pc2). On the other hand, in the section in which the rotor salient poles are separated from the stator magnetic poles Pa1 to Pc2, the inductance of the phase windings La to Lc decreases, and the rotor salient poles become the mechanical angle (60
), The inductance of the phase windings La to Lc is minimized at the center position (30 degrees, that is, the center of two adjacent magnetic poles).

One end of each of the phase windings La to Lc of each of the phases A, B and C is star-connected to each other, and the other end is connected to the terminal block T.
Are connected to the drive unit 10 via the lead lines la, lb, lc, ln. Furthermore, the neutral point N of the star connection
Is connected to the voltage midpoint M of the power supply circuit 13. Therefore, the wire harness between the SR motor SRM and the drive unit 10 has four lead lines la, lb, l from the terminal block T.
c, ln only.

Next, the SR motor SRM by the drive unit 10
Will be described. As shown in FIG. 5, the energization timing of the driving unit 10 is determined by switching pulses from the energization control unit 30 to the bases of the transistors TR1a to TR2c, the switching pulses PA to P having timings shifted from each other by π in electrical angle.
C, Pa to Pc are determined by inputting.
For example, the transistors TR1a to TR2c are TR1a → TR
Switching in the cyclic order of 2b → TR1c → TR2a → TR1b → TR2c → TR1a, A phase {phase winding current ia (positive direction)} → B phase {phase winding current ib (negative direction) → C phase} Phase winding current ic (positive direction)｝ → A phase {phase winding current ia (negative direction)｝ → B ｛phase winding current ib (positive direction)｝ → C {phase winding current ic (negative direction)} → A-phase winding current ia (positive direction)｝ Bidirectional energization of each phase is performed in the circulating order, and A-phase →
Excitation is performed in the circulation order of B phase → C phase → A phase. Furthermore, if the current is supplied in a region where the inductance of the phase windings La to Lc increases, a positive torque is generated.
At the time of driving of M, current is supplied in an area where the inductance is increased.
Since a negative torque is generated, energization is performed in a reduced inductance region during braking).

As described above, the bidirectional energization of each phase is performed, and each phase is excited to rotate the SR motor SRM. Therefore, the SR motor SRM is operated with a smooth rotation with little variation in output torque. . Then, at the time of energization and de-energization by the drive unit 10, the two capacitors C1 and C2 of the power supply circuit 13 work alternately for power supply or for regenerative charge accumulation. That is, one capacitor C1 or C2 regenerates the magnetic energy stored in the phase windings La to Lc, and the other capacitor C2 or C1
Since power is supplied to the phase windings La to Lc, magnetic energy is quickly regenerated and a voltage higher than the power supply voltage 2V is applied to the phase windings La to Lc. Therefore, the phase winding currents ia to
The rise and fall of ic become steep.

In the present embodiment, energization is started in a region where the inductance is reduced. This is because the inductance is small and can be neglected. Because it becomes.

As described above, in the present embodiment, the phase windings La to Lb are star-connected to each other, and the neutral point N of the star connection and the voltage midpoint M of the power supply circuit 13 are connected.
The wiring harness between the SR motor SRM and the driving unit 10 is
Only four lead lines la to lc and ln can be provided. Therefore, the size of the driving unit 10 can be reduced and the configuration thereof can be simplified, and the reliability can be increased.

Further, since the energizing circuit 15 has a six-arm bridge configuration, an inverter manufactured as a general-purpose module can be adopted, and the device can be manufactured very easily. Further, when energizing and de-energizing by the drive unit 10,
Since the two capacitors C1 and C2 of the power supply circuit 13 function alternately for power supply or for regenerative charge storage, the rising and falling of the phase winding currents ia to ic can be made steep. Therefore, output characteristics (rotational speed-torque characteristics) during high-speed rotation can be improved.

As described above, in the present embodiment, the two capacitors C1 and C2 are configured to alternately repeat charging and discharging. When the capacitances of the two capacitors are not exactly equal to each other, the capacitance error causes a difference between the terminal voltages of the two. There is a difference in size, and it may be enlarged. Therefore, stable operation of the SR motor SRM may be realized by detecting the voltage imbalance and changing the energization sequence based on the detection result.

Here, detection for detecting voltage imbalance
An example of the means (voltage imbalance detection determination circuit) will be described. As shown in the column (A) of FIG. 6, the voltage imbalance detection determination circuit 50 includes a detection circuit 52 for detecting a voltage imbalance between the capacitors C1 and C2, and a detection circuit 5
Comparator 5 for comparing and comparing the output of 2 with a predetermined threshold
4a and 54b.

The detection circuit 52 includes voltage dividing resistors R1 and R2 for detecting terminal voltages VC1 and VC2 of the capacitors C1 and C2.
3 and R2, R4 (where R1 = R2 >> R3 = R4)
And a well-known adder AD. In the adder AD, assuming that the resistance R5 = R6, the output of the adder AD is a sum VC1 + VC2 (hereinafter referred to as a sum voltage) of voltages between terminals of the capacitors C1 and C2. However, since the non-inverting terminal (+) is connected to the voltage midpoint M and the neutral point N, and the voltage VC2 between the terminals of the capacitor C2 is detected as a negative potential, the output VAD of the adder AD includes: [| VC2 |-|
VC1 |], and this output VAD is connected to capacitors C1 and C2.
Is proportional to the magnitude of the voltage imbalance.

The comparators 54a and 54b are provided with an adder A
The output VAD of D and a positive threshold R or the output VAD and a negative threshold S are compared and determined, and the determination signals SJ and SK are output.
These comparison results reflect the magnitude of the potential difference between the capacitors C1 and C2. That is, when the output VAD is between the positive threshold value R and the negative threshold value S (R>VAD> S), the sum voltage VC1 + VC2 is also set to the positive reference value Q, as shown in FIG. And a negative reference value P. That is, the terminal voltage VC1 of the capacitor C1 and the terminal voltage V
The voltage imbalance with C2 is small and the comparator 54a
And 54b are both positive (SJ> 0, S
K> 0).

When the output VAD is larger than the positive threshold value R (in the region shown by the oblique line rising to the right in FIG.
VAD >> 0), the sum voltage VC1 + VC2 is
It is smaller than the negative reference value P. That is, the terminal voltage VC2 of the capacitor C2 is considerably higher than the terminal voltage VC1 of the capacitor C1 (VC2 >> VC1), and the comparators 54a and 5b
4b are negative and positive (SJ <0, SK>
0).

On the other hand, when the output VAD is smaller than the negative threshold value S (in the region shown by the diagonally oblique line rising to the left in the figure and when VAD << 0), the total voltage VC1 + V
C2 is larger than the positive reference value Q. That is, the capacitor C
1 is much higher than the terminal voltage VC2 of the capacitor C2 (VC1 >> VC2). The judgment signals of the comparators 54a and 54b are positive and negative (SJ> 0, SK).
<0).

The above determination signals SK and SJ are input to a logic circuit 70 provided in the energization control unit 30. The logic circuit 70 includes a well-known JK flip-flop FF and an AND circuit. The logic circuit 70 is included in the conduction control unit 30 and includes conduction timing signals SA to SC from the main control unit 20 and determination signals from the comparators 54a and 54b. Based on SJ and SK, a selection signal CH1 or CH2 (both Hig) for selecting energization by PNP transistors TR1a to TR1c or energization by NPN transistors TR2a to TR2c.
Active). That is, in the energization control unit 30,
When energizing each phase in a predetermined circulation order based on the selection signal CH1 or CH2, the PNP transistors TR1a to TR1a
1c (when CH1 is active) or N
PN transistors TR2a to TR2c (CH
2 is active).

Although the figure shows the case of the A phase, the same applies to the B phase and the C phase. First, when the terminal voltage VC1 of the capacitor C1 and the terminal voltage VC2 of the capacitor C2 are approximately balanced, the logic circuit 70 outputs the selection signals CH1 and CH2 alternately. That is, JK
Since both the J and K inputs of the flip-flop FF are positive, the output (Q and Q) of the JK flip-flop FF is inverted at the rising timing every time a pulse of the energization timing signal SA is input. The product circuit AND outputs the selection signals CH1 and CH2 alternately. As a result, the transistors TR1a and TR2a switch in the usual circulating order.

When the terminal voltage VC2 of the capacitor C2 becomes considerably higher than the terminal voltage VC1 of the capacitor C1, the logic circuit 70 outputs only the selection signal CH2. That is, JK
The output of the flip-flop FF is [Q = Low, inverted Q = H
ig], the AND circuit AND outputs the selection signal C
Only H2 is output. As a result, the PNP transistor T
Instead of turning on R1a, NPN transistor TR2a becomes O
N, the capacitor C2 is discharged and the terminal voltage V
C2 drops, and the voltage imbalance is eliminated.

When the terminal voltage VC1 of the capacitor C1 becomes significantly higher than the terminal voltage VC2 of the capacitor C2, the logic circuit 70 outputs only the selection signal CH1. That is, JK
The output of the flip-flop FF is [Q = Hig, inverted Q = L
ow], the AND circuit AND outputs the selection signal C
Only H1 is output. As a result, the NPN transistor T
Instead of turning on R2a, the PNP transistor turns on TR1a and discharges from the capacitor C1, lowering the terminal voltage VC1 and eliminating the voltage imbalance.

Further, in this embodiment, the voltage doubler rectifier circuit is used for the power supply circuit 13, but the power supply circuit may be constituted by a battery. For example, as shown in column (A) of FIG. 7, the power supply circuit 72 includes a series circuit of batteries B1 and B2 and a series circuit of capacitors C1 and C2.
The middle point of connection between B1 and B2 is connected to the middle point of connection between capacitors C1 and C2 to form a middle voltage point M. Also, as shown in FIG. 7B, the power supply circuit 82 includes one battery BT and two capacitors C1 and C2, and the positive electrode of the battery is connected to the connection point between the capacitors C1 and C2. The connection point becomes the voltage middle point M after the capacitor C1 is charged after the start of the SR motor SRM.

Also when these batteries B1, B2, and BT are used, the two capacitors C1 and C2 alternately repeat charging and discharging as in the above embodiment. Therefore, the rise and fall of the phase winding currents ia to ic can be made steep to improve output characteristics (rotational speed-torque characteristics) during high-speed rotation.

Therefore, an SR motor can be used as a drive motor of an electric vehicle using a battery as a drive power source. Conventionally, the output voltage cannot be increased by increasing the number of batteries due to restrictions on the mounting dimensions and weight of the batteries, so it is difficult to employ an SR motor that has poor output characteristics at high speed rotation. However, such a problem has been overcome in this embodiment.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram illustrating a drive unit of a variable reluctance motor according to an embodiment.

FIG. 2 is an explanatory diagram of an operation of a driving unit.

FIG. 3 is a block diagram of a variable reluctance motor control system.

FIG. 4 is an explanatory diagram of a structure of a variable reluctance motor.

FIG. 5 is an explanatory diagram showing an inductance of a phase winding, a current change characteristic, and the like.

FIG. 6 is an electric circuit diagram of a voltage imbalance detection determination circuit and an explanatory diagram of a voltage imbalance determination operation.

FIG. 7 is an electric circuit diagram illustrating a driving unit using a power supply circuit having another configuration.

FIG. 8 is an electric circuit diagram showing a conventional variable reluctance motor driving device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Drive part 13 ... Power supply circuit 15 ... Electrification circuit TR1a, TR1b, TR1c ... PNP transistor TR2a, TR2b, TR2c ... NPN transistor C1, C2 ... Capacitor M ... Voltage middle point N ... Neutral point La, Lb, Lc ... Phase Winding SRM: Variable reluctance motor

Claims (3)

(57) [Claims] 1. A variable reluctance motor driving device for rotating a variable reluctance motor by energizing each phase winding of a variable reluctance motor in sequence from a DC power supply circuit, wherein the respective phase windings are connected to each other. Star was connected, and while connecting the voltage midpoint of the neutral point and the DC power supply circuit of the star connection, connection by switching the positive electrode or the negative electrode of the DC power supply circuit to each of the star-connected phase windings By doing the above
The energization of each phase winding is performed between the positive electrode and the voltage of the DC power supply circuit.
An energizing means that operates at the point-to-point voltage or the negative electrode-voltage midpoint voltage
Variable reluctance motor driving apparatus characterized by comprising. 2. The variable reluctance motor according to claim 1, wherein:
In the drive device of The energizing means is connected to each of the phase windings when energized.
The switching of the polarity of the DC power supply circuit is performed in phase order.
A variable reluctance motor drive device. 3. The variable reluctance motor according to claim 1,
In the drive device of The positive voltage and the negative voltage with respect to the voltage midpoint of the DC power supply circuit
Equipped with detection means for detecting voltage imbalance of pole side voltage
e, The energizing means is connected to each of the phase windings when energized.
The switching of the polarity of the DC power supply circuit is detected by the detecting means.
Each of the above voltages varies according to the output voltage imbalance.
Variable reluctance characterized by performing
Motor drive.