JP3255167B2 - Switch reluctance motor control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and a device for controlling a switched reluctance motor using an inverter device.

[0002]

2. Description of the Related Art Conventionally, a switched reluctance motor (hereinafter referred to as an SR motor), which has a low current and a large torque characteristic in principle compared to an AC motor and thus can be downsized because of its simple structure and can be greatly reduced in cost. ).

Generally, the generated torque τ of the SR motor is given by τ = (1/2) · (iu · iu · dLu / dθ + iv · iv · dLv / dθ + iw · iw · dLw / dθ) (1) expressed. Here, iu, iv, and iw are the phase winding currents of the SR motor, Lu, Lv, and Lw are the phase winding self-inductances of the SR motor, and θ is the position angle of the rotor of the SR motor.

FIG. 1 shows an S-pole having a stator having six poles and a rotor having four poles.
FIG. 7 is a diagram illustrating a relationship between a change in the self-inductance of each winding in the R motor with respect to a position angle of a rotor and an energization waveform. As can be seen from FIG. 1, the change in the self-inductance of each winding with respect to the rotation angle can be approximated to a triangular wave, and each has a phase difference of 30 ° in mechanical angle.

As can be seen from equation (1), the positive / negative value of the torque is determined by the rate of change of the inductance, and does not depend on the polarity of the current. Requires an inverter circuit and an inverter control device capable of supplying a rectangular wave current in a positive section.

The same energization control is generally performed also for SR motors having other combinations of the number of poles (for example, SR motors having a stator having 12 poles and a rotor having 8 poles).

FIG. 2 is an electric circuit diagram showing an inverter circuit for driving the SR motor.

This inverter circuit includes transistors Tu +, Tv +, Tw +, Tu-, Tv for controlling the energization.
-, Tw- are the upper side (+ side) and the lower side (-side) of the DC link.
And the + side transistors Tu +, Tv
+, Tw + emitter terminals and the negative side transistor Tu−,
A winding serving as a load is connected between the collector terminals of Tv− and Tw−, and return diodes Du +, Dv +, Dw +, Du−, and Dv that operate when the transistor is off.
− And Dw− are connected to the + side and − side of the DC link, respectively. The anodes of the freewheeling diodes Du +, Dv + and Dw + on the + side are connected to the collector terminals of the negative side transistors Tu−, Tv− and Tw−, respectively. Freewheel diodes Du-, Dv-,
The cathode of Dw- is a + side transistor Tu +, Tv +,
Each of them is connected to a Tw + emitter terminal.

In the switching mode of the inverter circuit, a mode 1 in which a DC voltage VDC is applied to both ends of the winding via a + -side transistor T + and a --side transistor T- {see FIG. Side transistor T
Mode 2 in which 0 voltage is applied to both ends of the winding by the-and-side freewheeling diodes D-, or 0 voltage is applied to both ends of the winding by the + side transistor T + and the + side freewheeling diode D + ((B) in FIG. 3 ( C), a mode 3 in which a DC voltage -VDC is applied to both ends of the winding via a + side return diode D + and a − side return diode D- {(D) in FIG.
There are three modes of reference｝. Since each phase of the SR motor is independent, only one phase is shown in FIG. In the following, only one phase is shown unless otherwise specified.

In order to control the winding current of the SR motor, a detection current is input to a "-" input of the hysteresis comparator, and a command current is input to a "+" input. A control device (see FIG. 4) for switching between the switching mode 3 and the detection current is input to the “-” input of the hysteresis comparator.
A command current is input to each + ”input to generate a pulse width modulation (chopping) signal, and an AND signal of the chopping signal and a commutation signal (a signal for selecting an energized phase) is used for a + side transistor. Control signal,
There is a control device shown in FIG. 6 in which a commutation signal is used as a control signal for a negative transistor.

A further description will be given.

The control device shown in FIG. 4 generates a chopping signal by inputting a detection current to a "-" input and a command current to a "+" input of a hysteresis comparator, and outputs the generated chopping signal to a + side transistor. Switching mode 1 and switching mode 3 can be switched by controlling the on / off state of both transistors Tr + and Tr− by supplying them to the gates of Tr + and − side transistor Tr−. Specifically, when the deviation between the detected current and the command current is negative, the switching mode 1
Is selected, and both transistors Tr are connected to both ends of the winding of the SR motor.
DC voltage VDC is applied via + and Tr- to increase the winding current. Conversely, when the deviation between the detected current and the command current is positive, the switching mode 3 is selected, and a DC voltage -VDC is applied to both ends of the winding of the SR motor via both return diodes D + and D-. Attenuate current.

By repeating these two operations, a waveform having a ripple having a hysteresis width with respect to the command current can be obtained as shown in FIG.

When the control device shown in FIG. 6 is adopted,
It works as follows. However, in the following description,
It is stated that the transistor is turned on when the gate signal of the transistor is "1".

If the detected current is less than the command current, a logical product signal of the "1" signal output from the hysteresis comparator and the commutation signal is supplied to the gate of the + -side transistor Tr +, and to the gate of the --side transistor Tr-. Is supplied with a commutation signal, a DC voltage VDC is applied to both ends of the corresponding winding through both transistors Tr + and Tr− selected by the commutation signal “1”, and the winding current increases. .

When the detected current rises and exceeds the command current by more than the hysteresis width, the output of the hysteresis comparator is inverted to "0" and supplied to the gate of the + side transistor Tr + via the AND gate. Since the chopping signal becomes “0”, the positive side transistor T
Only r + turns off. Of course, the negative side transistor T
r- remains on. As a result, zero voltage is applied to both ends of the winding by the negative transistor Tr− and the negative return diode D−. In this case, the winding current attenuates more slowly than in the case where the DC voltage -VDC is applied to both ends of the winding.

When the detected current attenuates and falls below the command current by more than the hysteresis width, the output of the hysteresis comparator becomes "1" and the positive side transistor Tr
DC voltage V via the + and-side transistors Tr-
DC is applied across the winding and the winding current increases.

In the case where the current-carrying phase shifts to another phase due to commutation, the commutation signal turns off both the + side transistor Tr + and the − side transistor Tr-, and the DC voltage −V
DC is applied across the winding and the winding current is rapidly attenuated. When the winding current becomes "0", both return diodes D + and D- are cut off, and both ends of the winding are opened.

[0019]

When the control device shown in FIG. 4 is employed, the winding current is attenuated by applying a DC voltage -VDC to both ends of the winding.
The number of switching increases, not only increases the switching loss in transistors and freewheeling diodes,
There is a disadvantage that the harmonic loss generated in the SR motor is increased.

On the other hand, when the control device shown in FIG. 6 is employed, the winding current can be gradually attenuated during non-commutation as compared with the control device shown in FIG. The time required for the output to be inverted to "1" becomes longer (see FIG. 7), and the number of switching times of the transistor can be reduced. That is, by changing the switching mode selection method (hereinafter, referred to as chopping method) at the time of inverter control, the number of switching times and the harmonic loss in the inverter circuit and the SR motor due to the switching can be reduced. In this regard, T.S. J. E. FIG. MILLLER, "
Switched Reluctance Motor
s and the Air Control ”, p53-
65, MAGNA PHYSICS PUBLISHI
NG OXFORD SCIENCE PUBLICA
TIONS, 1993.

However, since there is no description about the selection of an optimum chopping method for minimizing a loss according to the operating state of the SR motor, it cannot be said that the loss cannot be minimized according to the operating state of the SR motor. There are inconveniences.

[0022]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an SR motor control method and apparatus capable of minimizing a loss according to the operation state of the SR motor. And

[0023]

According to a first aspect of the present invention, in controlling an SR motor using an inverter device, the SR motor control method responds to a rotation speed of the switch reluctance motor by controlling an energization width. This is a method of inserting an inverter switching state in which the voltage across the winding of the switched reluctance motor is substantially “0” at a predetermined rate.

According to the SR motor control method of the present invention, when the switch reluctance motor is controlled using the inverter device, a signal for identifying whether the switch reluctance motor is in the motor operating state or the generator operating state is generated. This is a method of switching the chopping method of the inverter device in response to a signal.

According to a third aspect of the present invention, there is provided an SR motor control method for generating a signal for discriminating whether a switch reluctance motor is in a motor operating state or a generator operating state based on the phase of a conduction waveform with respect to a rotor position angle. is there.

According to the SR motor control method of the present invention, when the switch reluctance motor is controlled by using the inverter device, in response to the fact that the switch reluctance motor is performing a generator operation, in the vicinity of the command current, In order to increase the winding current of the switched reluctance motor, this method employs an inverter switching state in which the voltage across the winding is substantially "0".

According to a fifth aspect of the present invention, the inverter switching state is set so that the DC section voltage of the inverter device is applied immediately after commutation until the winding current of the switched reluctance motor approaches the command current. It is a method of holding.

According to a sixth aspect of the present invention, there is provided an SR motor control device for controlling a switch reluctance motor by using an inverter device. And inverter control means for inserting an inverter switching state in which the voltage across the winding of the switched reluctance motor is substantially "0".

According to a seventh aspect of the present invention, there is provided an SR motor control device for controlling a switch reluctance motor using an inverter device, wherein a signal for identifying whether the switch reluctance motor is in a motor operation state or a generator operation state is generated. Identification signal generating means, and inverter control means for switching the chopping method of the inverter device in response to this signal.

According to an eighth aspect of the present invention, as the identification signal generating means, the switch reluctance motor determines whether the motor is in the motor operating state or the generator operating state based on the phase of the conduction waveform with respect to the position angle of the rotor. A signal that generates a signal to be generated is adopted.

According to a ninth aspect of the present invention, there is provided an SR motor control device for controlling a switch reluctance motor using an inverter device, wherein a command current is controlled in response to the switch reluctance motor performing a generator operation. In the vicinity, there is provided an inverter control means employing an inverter switching state in which the voltage across the winding is substantially "0" in order to increase the winding current of the switched reluctance motor.

According to a tenth aspect of the present invention, the inverter switching state is set so that the DC section voltage of the inverter device is applied immediately after commutation until the winding current of the switched reluctance motor approaches the command current. It further includes inverter control means for holding.

[0033]

According to the SR motor control method of the present invention, when controlling the switch reluctance motor using the inverter device, the switch reluctance motor is controlled at a predetermined ratio with respect to the energization width in response to the rotation speed of the switch reluctance motor. Since an inverter switching state in which the voltage between both ends of the winding of the switch reluctance motor is substantially “0” is inserted, the number of switching operations required during the energization period can be reduced, and the loss can be greatly reduced. Can be.

According to the SR motor control method of the second aspect,
In controlling the switch reluctance motor using the inverter device, a signal for identifying whether the switch reluctance motor is in the motor operation state or the generator operation state is generated, and the chopping method of the inverter device is switched in response to this signal. Therefore, the loss can be greatly reduced by reducing the number of times of switching in response to the operation of the electric motor, and the electric brake can be applied by the operation of the generator.

According to the SR motor control method of claim 3,
A signal for identifying whether the switch reluctance motor is in the motor operating state or the generator operating state is generated based on the phase of the conduction waveform with respect to the position angle of the rotor. Whether the motor is in the motor operating state or the generator operating state can be easily and reliably identified.

According to the SR motor control method of claim 4,
In controlling the switch reluctance motor using the inverter device, in order to increase the switch reluctance motor winding current in the vicinity of the command current in response to the switch reluctance motor performing a generator operation. Since the inverter switching state in which the voltage at both ends of the line is substantially “0” is adopted, the number of times of switching during the operation of the generator can be reduced and the loss can be greatly reduced.

According to the SR motor control method of claim 5,
Immediately after commutation, the inverter switching state is maintained so that the DC section voltage of the inverter device is applied until the winding current of the switched reluctance motor reaches the vicinity of the command current. ,
Immediately after commutation, the winding current can be rapidly started.

According to the SR motor control device of claim 6,
In controlling the switch reluctance motor using the inverter device, by the inverter control means,
In response to the rotational speed of the switch reluctance motor,
An inverter switching state in which the voltage across the windings of the switched reluctance motor is substantially “0” can be inserted at a predetermined ratio with respect to the conduction width.

Therefore, it is possible to reduce the number of times of switching required during the energization period, and to greatly reduce the loss.

According to the SR motor control device of claim 7,
In controlling the switch reluctance motor using the inverter device, a signal for identifying whether the switch reluctance motor is in the motor operation state or the generator operation state is generated by the identification signal generation means, and the signal is identified by the inverter control means. The chopping method of the inverter device can be switched in response.

Therefore, in response to the operation of the motor, the number of switching operations can be reduced to greatly reduce the loss, and the electric brake can be applied by the operation of the generator.

According to the SR motor control device of claim 8,
Since the identification signal generating means employs a signal generating a signal for identifying whether the switch reluctance motor is in the motor operating state or the generator operating state based on the phase of the conduction waveform with respect to the rotor position angle, In addition to the function of claim 7, it is possible to easily and reliably identify whether the switch reluctance motor is in the motor operating state or the generator operating state.

According to the SR motor control device of claim 9,
In controlling the switch reluctance motor using the inverter device, by the inverter control means,
Inverter switching state in which the voltage across the winding is substantially "0" in order to increase the winding current of the switch reluctance motor in the vicinity of the command current in response to the switch reluctance motor performing the generator operation. Can be adopted.

Therefore, the number of switching operations during the operation of the generator can be reduced, and the loss can be greatly reduced.

In the SR motor control device according to the tenth aspect, the inverter switching is performed such that the DC section voltage of the inverter device is applied immediately after commutation until the winding current of the switched reluctance motor approaches the command current. Since the inverter control means for maintaining the state is further included, in addition to the effect of the ninth aspect, the winding current can be rapidly raised immediately after commutation.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the SR motor control method and apparatus of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 11 is a schematic diagram showing an embodiment of the SR motor control device of the present invention.

In this SR motor control device, the winding 1 of the SR motor is connected between the emitter terminal of the + side transistor T + and the collector terminal of the − side transistor T−, and the + side and the − side transistor T of the DC link are connected. A + side return diode D + is connected between the negative side of the DC link and the + side
The −side freewheeling diode D− is connected between the emitter terminal of the side transistor T +.

The winding current flowing through the winding 1 is detected by the current detector 2, and the detected current and the command current output from the command current (torque command) generating unit 3 are supplied to the hysteresis comparator 4. Generate a pulse width modulated (chopping) signal.

It is to be noted that the hysteresis comparator 4
The detection current is input to the “−” input, and the command current is input to the “+” input.The commutation signal output from the commutation signal generator 5, the return signal output from the return signal generator 6, And the chopping signal is supplied to the AND gate 7, the AND signal output from the AND gate 7 is supplied to the gate of the positive transistor T +, and the commutation signal is supplied to the gate of the negative transistor T-.

The return signal generator 6 outputs a return signal whose high-level ("1" signal) period changes according to the rotation speed.

Therefore, by controlling the + side transistor T + by the logical product signal of the commutation signal, the return signal and the chopping signal, and controlling the − side transistor T− by the commutation signal, the number of times of switching is reduced, and The loss can be minimized according to the operating state of the motor.

Further description will be given.

The voltage equation for the one-phase winding of the SR motor is expressed as follows, where the winding applied voltage is vL. vL = R ・ i + d ｛L (θ) ・ i｝ / dt = R ・ i + L (θ) ・ di / dt + ω ・ K ・ i (2) where L (θ) is for each rotor position angle θ , R is the winding resistance, i is the winding current, ω is the rotation speed of the SR motor, and t is the time. Also, K = L (θ) /
dθ. The sign of K is inverted by the position angle of the rotor (see FIG. 1).

When the response of the winding current when the speed control system of the SR motor is configured by the SR motor drive system using the SR motor control device of FIG. 6 is considered for each rotation speed by the equation (2), As the rotation speed ω increases,
The third term of the equation (2) (hereinafter referred to as the back electromotive voltage) becomes larger than that of the low speed, and the inverter DC voltage VD
The change in current when C is applied becomes gentle. And
The rotation speed ω at which the detected current reaches the command current by continuously applying the inverter DC voltage VDC over the energization period
When the rotation speed ω is further increased, the rotation speed ω in FIG.
As shown in (1), no switching is performed during the energization period (this is a state in which the inverter output voltage applied to both ends of the winding is saturated to the maximum value).

On the other hand, in the low speed region where the back electromotive voltage is small and the detected current reaches the command current in a shorter time than the conduction period when the inverter DC voltage VDC is applied to both ends of the winding, the output of the hysteresis comparator 4 is responded. As shown in FIG. 8A, switching is performed over the energization period, and as a result, the average voltage applied to both ends of the winding is controlled to be smaller than the inverter DC voltage VDC.

That is, the magnitude of the voltage (required) to be output from the inverter in order to make the winding current follow the command current changes in response to the rotation speed. Become. Focusing on this point, by performing the waveform control as shown in FIG. 9 in the low-speed rotation range, the number of switching times can be reduced.

According to this method, the switching mode 2 (terminal voltage = 0) is inserted at a predetermined ratio with respect to the energizing width during the energizing period, and the switching period is shortened. Is to be reduced.

When the effect of reducing the loss (improving the efficiency) was actually measured at 1/6 of the rated speed, the switching mode 2 was inserted at 60% of the current-carrying width.
The harmonic loss of the R motor could be reduced by 17%, and the SR motor efficiency could be improved by about 4% (see FIG. 10).

In the low-speed operation, the SR motor control device shown in FIG. 11 always fixes the switching state of the inverter to the switching mode 2 regardless of the state of the chopping signal while the return signal is "0". 12 can reduce the number of switching times.
See middle (b). Conversely, the inverter output voltage is increased (for example, the inverter DC voltage VD
In the case of performing a high-speed operation that needs to apply C), the period in which the recirculation signal is “1” and the period in which the commutation signal is “1” are made to coincide with each other, thereby achieving the same operation as the SR motor control device in FIG. 12 (see (a) of FIG. 12).

As a result, an optimum chopping method according to the rotation speed can be realized.

FIG. 15 is a block diagram showing a main part of another embodiment of the SR motor control device of the present invention.

This SR motor control device outputs a chopping signal by inputting an actual current (detected current) and a command current, and outputs a logical sum signal by inputting a chopping signal and a motor / generator mode signal. An OR gate 12, a first AND gate 13 which receives a chopping signal and a commutation signal as inputs, and outputs a positive transistor gate signal, and an OR gate 1
A second AND gate 14 which receives the OR signal and commutation signal from node 2 and outputs a negative-side transistor gate signal
And

Therefore, when the motor / generator mode signal is "1", regardless of the chopping signal,-
During the period when the commutation signal is “1”,
1 "is supplied, and the same chopping method as that of the SR motor control device in FIG. 6 can be realized (see section A in FIG. 16).

On the contrary, the motor / generator mode signal is "0".
In the case of (1), the AND signal of the chopping signal and the commutation signal is supplied to the gates of the + side transistor and the − side transistor, so that the same chopping method as that of the SR motor control device of FIG. 4 can be realized (FIG. 16). Middle section B).

FIG. 17 is a block diagram showing an example of the configuration of a device for generating a motor / generator mode signal.

In this device, a u-phase winding inductance change rate storage unit 15u, a v-phase winding inductance change rate storage unit 15v, and a w-phase winding inductance change rate storage unit 15 that store the winding inductance change rate of each phase with the rotor position angle θ as an input. The winding inductance change rate storage unit 15w and the stored winding inductance change rate of each phase are input to perform polarity detection (“1” is output when the polarity of the change rate is positive, and is detected when the polarity is negative. Polarity detectors 16u, 16v, and 16w, and AND gates 17u, 17v, and 17w that receive a commutation signal of each phase and a corresponding polarity detection signal to output a logical product signal.
And an OR gate 18 which receives all the AND signals and outputs a motor / generator mode signal.

Therefore, for example, if the u-phase commutation signal is “
In the period of 1 ", a signal responding to the polarity of the inductance change rate of the u-phase winding (" 1 "in motor operation," 1 "in generator operation)
0 ") is obtained as the motor / generator mode signal.

Further description will be given.

When the motor operation is performed, the energization control is performed during the period when K is positive (see FIG. 13). Therefore, as can be seen from the equivalent circuit of the motor operation in FIG. 14A, if the applied voltage vL is set to 0 in order to attenuate the winding current, ω · K · i which is the third term of the equation (2) As a result, the winding current is attenuated.

Conversely, when performing the generator operation, the energization control is performed while K is negative (see FIG. 13). Therefore, as can be seen from the equivalent circuit of the motor operation in (b) of FIG. 14, when the winding applied voltage vL is set to 0, the winding current increases due to ω · K · i which is the third term of the equation (2). I do.

For this reason, for example, when the SR motor is operated in the four-quadrant by the SR motor control device shown in FIG. Although it is set to 0, the winding current increases. Therefore, not only cannot the winding current be controlled to a predetermined value, but also the inconvenience that the allowable current of the inverter switching element is exceeded and the element is destroyed occurs.

To solve this inconvenience, it is necessary to use S in FIG.
As the R motor control device, a configuration for selecting the switching mode 3 at the time of current decay and a configuration for setting the applied voltage vL = −VDC to surely attenuate the winding current may be employed, as described above. In addition, there is a disadvantage that the loss in the inverter and the SR motor is increased.

Therefore, the chopping method obtained by the SR motor control device shown in FIG. 6 may be selected for the motor operation, and the same chopping method as that of the SR motor control device shown in FIG. 4 may be selected for the generator operation. In this case, the number of switching operations can be reduced in the motor operation to reduce the harmonic loss of the inverter and the SR motor, and a drive system that requires a high-speed speed control response (for example, a drive system for feeding a machining table of a machine tool). The electric brake can be applied by the essential generator operation.

FIG. 18 is a block diagram showing a main part of still another embodiment of the SR motor control device of the present invention.

In this SR motor control device, a hysteresis comparator 21 which outputs a chopping signal by inputting the actual current (detected current) and the command current (the detected power is input to the “−” input, and the command current is input to the “+” input, respectively) And an OR gate 22 that receives the chopping signal and the motor / generator mode signal and outputs a logical sum signal, and a first AND gate 23 that receives the chopping signal and the commutation signal as inputs and outputs a + side transistor gate signal. A second AND gate 24 which receives the logical sum signal and the commutation signal from the OR gate 22 and outputs a logical product signal (chopping signal), and a commutation signal is supplied to a clock terminal, and the second AND gate 24 AND signal is supplied to the clear terminal, and the Q output signal is There becomes "1", D flip-flop 25 to the Q signal at the fall of the logical product signal becomes "0"
And a third AND gate 2 that receives the logical product signal from the second AND gate 24 and the Q output signal from the D flip-flop 25 and outputs a negative transistor gate signal
6.

The operation of the SR motor control device is as follows.

When the motor / generator mode signal is "0", the chopping signal is ANDed with the commutation signal and supplied to one input of the third AND gate 26. An output signal is supplied to the other input terminal.

The Q output signal from the D flip-flop 25 is set to "1" at the rise of the commutation signal (see arrow 1 in FIG. 19). Immediately after the commutation, "1" is output from the hysteresis comparator 21 in order to make the winding current (detection current) follow the command current, so that both "1" are applied to the gates of the positive and negative transistors.
Is supplied (see section A in FIG. 19). That is, switching mode 1 is selected, and the inverter DC voltage VDC can be applied to both ends of the winding.

Eventually, when the winding current exceeds the command current by the hysteresis width, the chopping signal (the output of the hysteresis comparator 21) is inverted to “0”. As a result, "0" is supplied to both the gates of the + side transistor and the-side transistor, switching mode 3 is selected, and a DC voltage -VDC is applied to both ends of the winding. Further, the input of the clear terminal CL of the D flip-flop 25 is connected to the second AND gate 2 receiving the chopping signal.
As a result of the output of No. 4, the output becomes "0", the Q output signal is set to "0" (see arrow 2 in FIG. 19), and is held until the next rise of the commutation signal.

Therefore, an AND signal with the Q output signal of the D flip-flop 25 is supplied to the gate of the negative transistor, and the gate is always kept off.

Then, the selected switching mode 3
As a result, the winding current is attenuated and the chopping signal becomes "1".
When "1" is supplied to the gate of the positive transistor, the gate of the negative transistor remains "0" due to the Q output signal of the D flip-flop 25, so that the switching state of the switching mode 2 is established. ,
The winding current gradually rises due to the back electromotive voltage.

Thereafter, by repeating the switching mode 2 and the switching mode 3, the SR motor can be controlled so as to keep the winding current near the command current.

This SR motor control device is the same as the SR motor control device shown in FIG.
Although the circuit is slightly more complicated than the motor control device, it is possible to reduce the number of times of switching during the operation of the generator and reduce the harmonic loss accompanying the switching, so that the application where the operation of the generator lasts for a long time (for example, It becomes the most suitable control device for the driving source of an electric vehicle).

The description will be made further.

During the operation of the generator, as described above, since the polarity of the back electromotive voltage is inverted with respect to the case of the operation of the motor, the direction of the winding current change in the switching mode 2 starts to increase. Therefore, the switching mode 2 is used to increase the winding current, and the DC voltage -VDC is applied to both ends of the winding by the switching mode 3 to attenuate the winding current.

In switching mode 1, the voltage applied to the winding RL (winding resistance R and inductance L) to increase the winding current is equal to the sum of the inverter DC voltage and the back electromotive voltage (VDC + ω · In contrast, in the switching mode 2, the voltage applied to the RL of the winding becomes smaller as only the back electromotive voltage (ω · K · i), so that the winding current changes slowly. Therefore, the number of times of switching can be reduced, and the accompanying harmonic loss in the inverter and the SR motor can be reduced.

However, in the SR motor, since the back electromotive force is also proportional to the winding current i, the following sequence processing is performed.

(1) Immediately after commutation, the switching mode 1 is selected until the vicinity of the command current value, and the winding current is rapidly raised.

(2) In the vicinity of the command current value, when the current is attenuated, the DC voltage -VDC is applied in the switching mode 3, and when the current is increased, the switching mode 2 is selected, and the winding is induced by the winding induced voltage ω · K · i. Increase line current.

By employing the SR motor control device shown in FIG. 18, the above sequence processing can be achieved.

As can be seen from the above description, by switching the chopping method of the inverter according to the operation state of the SR motor, the number of times of switching can be reduced. In addition, electromagnetic noise can be reduced (reduced by several dBA or more).

According to the present invention, the number of times of switching can be reduced.
If it is set equal to the number of switchings of the R motor control device, for example, the hysteresis width (that is, current ripple) of the hysteresis comparator that compares the detected current with the command current can be reduced, and the torque ripple caused by the current ripple can be reduced. Can be reduced.

In the above embodiment, the case where the current is controlled in the inverter is described as an example. However, it is needless to say that the present invention can be applied to the case where the voltage is controlled in the inverter.

[0095]

According to the first aspect of the present invention, it is possible to reduce the number of times of switching required during the energization period, and to achieve a special effect that the loss can be greatly reduced.

According to the second aspect of the present invention, the loss can be greatly reduced by reducing the number of switching operations in response to the operation of the motor, and the electric brake can be applied by the operation of the generator. It has the unique effect of being able to.

The invention of claim 3 has a special effect that, in addition to the effect of claim 2, it is possible to easily and reliably identify whether the switch reluctance motor is in the motor operating state or the generator operating state. .

The invention of claim 4 has a specific effect that the number of switching operations during the operation of the generator can be reduced to greatly reduce the loss.

The invention of claim 5 has a unique effect that the winding current can be rapidly raised immediately after commutation in addition to the effect of claim 4.

The invention of claim 6 has a specific effect that the number of times of switching required during the energization period can be reduced, and the loss can be greatly reduced.

According to the seventh aspect of the present invention, the loss can be greatly reduced by reducing the number of times of switching in response to the operation of the motor, and the electric brake can be applied by the operation of the generator. It has the unique effect of being able to.

The invention of claim 8 has a special effect that the switch reluctance motor can easily and reliably discriminate between the motor operating state and the generator operating state in addition to the effect of claim 7. .

The ninth aspect of the invention has a specific effect that the number of switching operations during the operation of the generator can be reduced to greatly reduce the loss.

The tenth aspect of the present invention has a unique effect that the winding current can be rapidly raised immediately after commutation in addition to the effect of the ninth aspect.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a driving method of an SR motor.

FIG. 2 is an electric circuit diagram showing a main circuit of an inverter that drives an SR motor.

FIG. 3 is a diagram illustrating a switching state of the inverter of FIG. 2;

FIG. 4 is an electric circuit diagram showing a configuration of an example of a conventional SR motor control device.

FIG. 5 is an explanatory diagram illustrating an operation of the SR motor control device of FIG. 4;

FIG. 6 is an electric circuit diagram showing a configuration of another example of the conventional SR motor control device.

FIG. 7 is an explanatory diagram illustrating an operation of the SR motor control device of FIG. 6;

FIG. 8 is a diagram illustrating changes in winding current and applied voltage during low-speed rotation and high-speed rotation.

FIG. 9 is an explanatory diagram illustrating reduction of the number of times of switching by utilizing the switching mode 2.

FIG. 10 is a diagram showing an improvement in motor efficiency and a loss reduction effect by utilizing the switching mode 2.

FIG. 11 is an electric circuit diagram showing one embodiment of the SR motor control device of the present invention.

FIG. 12 shows high-speed rotation and low-speed rotation of FIG.
FIG. 3 is a diagram showing signal waveforms of various parts of the first SR motor control device.

FIG. 13 is a diagram showing energization phases of the SR motor when the motor operates and when the generator operates.

FIG. 14 is an electric circuit diagram showing an equivalent circuit for one phase when the motor of the SR motor operates and when the generator operates.

FIG. 15 is an electric circuit diagram showing a main part of another embodiment of the SR motor control device of the present invention.

16 is a diagram showing signal waveforms at various parts of the SR motor control device of FIG.

FIG. 17 is a block diagram illustrating an example of a configuration of a device that generates a motor / generator mode signal.

FIG. 18 is an electric circuit diagram showing a main part of still another embodiment of the SR motor control device of the present invention.

19 is a diagram showing signal waveforms of various parts of the SR motor control device of FIG.

[Explanation of symbols]

5 Commutation signal generator 6 Reflux signal generator 7 AND gate 12 OR gate 14 Second AND gate 15u u-phase winding inductance change rate storage unit 15v V-phase winding inductance change rate storage unit 15w w-phase winding inductance change rate storage Unit 16u, 16v, 16w Magnetic detector 17u, 17v, 17w AND gate 18 OR
Gate 22 OR gate 23 First AND gate 24 Second AND gate 25 D flip-flop 26 Third AND gate

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 5/05 H02P 7/63

Claims (10)

(57) [Claims] 1. A method for controlling a switch reluctance motor using an inverter device, the method comprising:
A method of controlling a switched reluctance motor, comprising inserting an inverter switching state in which a voltage across a winding of a switched reluctance motor is substantially "0" at a predetermined ratio to a conduction width. 2. A method for controlling a switched reluctance motor using an inverter device, comprising: generating a signal for identifying whether the switched reluctance motor is in a motor operating state or a generator operating state; A method for controlling a switched reluctance motor, wherein a chopping method of an inverter device is switched. 3. The switched reluctance motor according to claim 2, wherein a signal for identifying whether the switched reluctance motor is in the motor operating state or the generator operating state is generated based on the phase of the conduction waveform with respect to the position angle of the rotor. Control method. 4. A method of controlling a switched reluctance motor using an inverter device, the method comprising controlling a switched reluctance motor winding in the vicinity of a command current in response to the switched reluctance motor performing a generator operation. A method for controlling a switched reluctance motor, comprising employing an inverter switching state in which a voltage across a winding is substantially "0" to increase a line current. 5. The inverter switching state according to claim 4, wherein immediately after the commutation, the inverter switching state is maintained such that the DC section voltage of the inverter device is applied until the winding current of the switched reluctance motor reaches the vicinity of the command current. Switch reluctance motor control method. 6. An apparatus for controlling a switch reluctance motor using an inverter device, the apparatus being responsive to a rotation speed of the switch reluctance motor.
Inverter control means (5) for inserting an inverter switching state in which the voltage across the winding of the switched reluctance motor is substantially "0" at a predetermined ratio to the conduction width.
(6) A switch reluctance motor control device including (7). 7. An apparatus for controlling a switched reluctance motor using an inverter device, wherein the identification signal generating means (15u) generates a signal for identifying whether the switched reluctance motor is in a motor operating state or a generator operating state. (15v) (15w) (16u) (16
v) (16w) (17u) (17v) (17w) (1
8) and inverter control means (12) (1) for switching the chopping method of the inverter device in response to this signal.
4) A switch reluctance motor control device comprising: 8. The identification signal generating means (15u) (15
v) (15w) (16u) (16v) (16w) (17
u) (17v), (17w), and (18) generate a signal for identifying whether the switch reluctance motor is in the motor operating state or the generator operating state based on the phase of the conduction waveform with respect to the position angle of the rotor. 8. The switch reluctance motor control device according to claim 7, wherein: 9. An apparatus for controlling a switch reluctance motor using an inverter device, the switch reluctance motor being wound near a command current in response to the switch reluctance motor performing a generator operation. Inverter control means (22) (24) (2) adopting an inverter switching state in which the voltage between both ends of the winding is substantially "0" in order to increase the line current.
5) A switch reluctance motor control device including (26). 10. Inverter control means (22) for maintaining an inverter switching state so that a DC section voltage of the inverter device is applied immediately after commutation until the winding current of the switched reluctance motor approaches the command current. The switch reluctance motor control device according to claim 9, further comprising (23), (24), (25), and (26).