JP3393366B2 - Device and method for detecting rotor position of sensorless motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for detecting the position of a rotor of a sensorless motor that operates without a rotational position sensor, and more particularly to a stator that changes depending on the positional relationship between the rotor and the stator. The present invention relates to detecting the position of a rotor from changes in the inductance of a winding.

[0002]

2. Description of the Related Art FIG. 14 shows a conventional general sensorless motor and its drive circuit. Reference numeral 1 is a stator, 3 is a winding wire, and 5 is a rotor which rotates about a rotating shaft 4. The stator 1 includes six stator salient poles 2 and three windings 3
(Only a pair of U phases U1 and U2 are shown for simplification). The rotor 5 is made of laminated steel plates, extends radially outward from the rotation shaft 4 of the rotor 5, and is arranged at a uniform interval in the circumferential direction around the periphery of the rotor 5.
Each rotor salient pole 6 is configured. Like the rotor 5,
The stator 1 is also made of laminated steel plates.

The windings 3 of the stator salient poles 2 facing each other in the diametrical direction are connected in series so as to generate a magnetic field in the same direction to form a phase winding. The number of windings is three (U, V,
W). For simplicity, V and W of the coil set are not shown, but the stator salient poles that are combined with these phase windings are labeled with “V” and “W”.

Reference numeral 7 is a drive circuit for driving the sensorless motor, and only a basic electric circuit used for exciting the U-phase windings U1 and U2 of the sensorless motor is shown. 8a and 8b turn on and off the current flowing through the U-phase winding 3.
A pair of FF transistors, 9a and 9b, are diodes for flowing the counter electromotive force generated when the transistors 8a and 8b are turned off in a regenerating direction, and 10 is a power supply for supplying a current for driving the sensorless motor. Bus voltage, 11 is a position detection sensor for detecting the rotational position of the rotor 5, 12 is ON-OFF of the transistor pair 8a, 8b
Is a control circuit for controlling.

Next, the operation will be described with reference to FIGS. In the case of a sensorless motor, when the stator salient poles 2 are excited, the rotor salient poles 6 are magnetically attracted and rotate in a direction in which the magnetic resistance of the rotor salient poles 6 is minimized. Does not depend on magnetic poles. Therefore, the current supplied from the drive circuit 7 is only one-way current. Then, the phase windings U, V, W are sequentially excited, and the rotor salient poles 6 are opposed to each other in synchronization with the excited salient poles 2 of the stator to rotate the rotor 5.

First, when the transistor pair 8a, 8b is turned on to the U-phase winding 3, a current flows in the order of power source 10 → transistor 8a → winding U1 and U2 → transistor 8b. When the transistor pair 8a, 8b is turned off, a back electromotive force is generated in the windings U1 and U2. The energy of this counter electromotive force is regenerated through the diode 9a → the winding U1 and U2 → the diode 9b. This exciting operation is sequentially performed on each winding U, V, W to perform a rotating operation as a motor. The ON / OFF switching timing of the transistor pair 8a, 8b is controlled by the control circuit 12 based on the information from the position detection sensor 11 which detects the rotational position of the rotor 5.
Done by

FIGS. 15A to 15D show the positional relationship between the stator salient poles 2 and the rotor salient poles 6. Describing based on the U phase, when a voltage is applied to the U phase when the stator salient pole 2 and the rotor salient pole 6 are separated as shown in FIG. 15A, the stator salient pole 2 is excited and magnetized. The rotor salient pole 6 closest to the stator salient pole 2 is magnetically attracted by the attraction force. Due to the magnetic attraction, the rotor salient poles 6 approach the stator salient poles 2 as shown in FIG. Further, the rotor salient poles 6 approach the stator salient poles 2, and the stator salient poles 2 and the rotor salient poles 6 face each other as shown in FIG. At this time, the attraction force acting on the rotor salient poles 6 is only in the diametrical direction, and torque for rotating the rotor 5 is not generated. Further, when the rotor 5 rotates as shown in FIG. 15D, a force in the rotational direction acts on the rotor salient poles 6 again, and a rotational torque is generated in the rotor 5.
The rotational torque generated at this time has a direction opposite to that of FIGS. If the rotor 5 is rotating clockwise, the braking force is to stop the rotation.

In order to rotate the rotor 5 in one direction,
It is necessary to always generate torque in the same direction. Therefore, as shown in FIG. 15C, the excitation of the stator salient pole 3 must be stopped before the stator salient pole 3 and the rotor salient pole 6 face each other. As described above, in order to rotate the sensorless motor in a certain direction, it is necessary to switch the timing of energizing the stator winding 3 in synchronization with the position of the stator salient pole 2 with respect to the rotor salient pole 6. For this reason, conventionally, in order to detect the position of the rotor 4, the position detection sensor 11 such as a resolver detects the position of the rotor 5, and the rotor position signal is fed back to the control circuit 12. The salient pole winding 3 was energized in synchronization with the position of the rotor 5.

[0009]

However, by providing the position detection sensor 11 as in the conventional sensorless motor driving device, the number of connections coming out from the sensorless motor increases, so that a special sensor such as a compressor is used. When moving in space, the number of terminals for connecting the inside and the outside increases, which limits the shape and cost. Therefore, it is desirable to eliminate the position detection sensor 11.

In the case of a sensorless motor, unlike the DC motor, since the rotor 5 has no magnet, it is not possible to utilize the change in the magnetic flux interlinking with the stator winding 3. Therefore,
The position of the rotor salient pole 6 can be detected by utilizing the characteristic of the sensorless motor that the inductance of the winding 3 of the stator salient pole 2 changes depending on the position of the rotor salient pole 6 with respect to the stator salient pole 2. .

FIG. 16 shows a general change in the inductance of the stator salient pole winding with respect to the rotation angle of the rotor salient pole. The rotation angle θ1 in FIG. 16 has the smallest inductance, and the positional relationship between the stator salient poles and the rotor salient poles is shown in FIG.
It looks like. When rotating clockwise from there as shown in FIG. 15B, the inductance of the stator salient pole winding increases as shown by θ2 in FIG. At the position of FIG. 15C, the maximum value is obtained as θ3 in FIG. Further, when it is rotated as shown in FIG. 16D, the inductance is reduced as shown by θ4 in FIG. In this way, the magnitude of the winding inductance of the stator salient pole changes periodically as shown in FIG. 16 depending on the position of the rotor salient pole with respect to the stator salient pole.

Therefore, the position of the rotor salient poles relative to the stator salient poles when exciting the stator windings is determined in advance, the inductance of the stator windings at that time is determined, and when the value reaches the fixed value If the timing for exciting the salient salient poles is set, it is possible to excite the stator salient poles in synchronization with the rotor salient poles without providing the position detection sensor 11 of FIG.

Thus, if the value of the inductance is known, the position of the rotor salient pole with respect to the stator salient pole can be estimated. As can be seen from FIG. 16, the rotor salient pole angle θ3 is symmetrical. Therefore, the position of the rotor salient pole cannot be uniquely detected from the value of the inductance. However, due to the drive timing of the sensorless motor, when any stator salient pole is excited, the winding inductance of the stator salient pole that was excited immediately before that is decreasing. When the value is detected, the position of the rotor salient pole with respect to the stator salient pole is uniquely determined.

However, the positional relationship with the stator salient pole can be known only from the positional relationship with the rotor salient pole closest to the stator salient pole, and the positional relationship with a fixed salient pole of the rotor is unknown. . However, the timing of exciting the stator salient poles is determined by the position of the rotor salient poles in the vicinity of the stator salient poles, rather than switching by the positional relationship with the rotor's fixed salient poles. Is not necessary.

As described above, the position of the rotor salient pole is detected by making use of the characteristics of the sensorless motor and detecting the inductance of the stator salient pole winding, as disclosed in, for example, Japanese Patent Publication No. 8-501920. In the described rotor position sensing device for a switching reaction motor without a shaft position sensor, a continuously varying signal is applied to the unexcited stator salient pole winding of a sensorless motor, resulting in an output. The position of the rotor is detected by detecting the amplitude and phase of the current that flows. However, it requires a continuously varying signal and a circuit to amplify it, and a switching circuit to connect these signals to the stator salient pole windings that are not excited. There was a problem that became complicated.

The present invention has been made in order to solve the above-mentioned problems, and a stator circuit for a rotor salient pole of a sensorless motor can be formed by a simple circuit without using a dedicated rotational position detecting sensor. An object of the present invention is to obtain a rotor position detecting device for a sensorless motor that detects a position of a pole and a method thereof.

[0017]

A rotor position detecting device for a sensorless motor according to the present invention supplies a power source via a step function signal generating circuit for generating a step function signal and a resistor for determining a time constant during transient response. A stator winding connected, a switch for applying a voltage applied from the power source to the stator winding and the resistor as a step function voltage based on the step function signal, and the fixed by the step function voltage An inductance detection circuit that detects the voltage or current during the transient response that occurs in the child winding and the resistance, and is determined in advance in accordance with the detection voltage or current detected by this inductance detection circuit and the position of the rotor salient pole. was voltages or on the basis of a current, a rotational position detecting circuit for detecting the position of the rotor salient poles, wherein said step Originating step function signal of No. generating circuit
Stator to drive the sensorless motor
The number of times the voltage is applied to the windings, or more
To do.

[0018]

Further, a step function signal generating circuit for generating a step function signal, a stator winding connected to a power source via a resistor that defines a time constant during transient response, and a voltage applied from the power source are A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. Which is detected by the inductance detection circuit and the stator winding of the other phase of the phase currently being excited by the inductance detection circuit and the position of the rotor salient pole. And a rotational position detection circuit that detects the position of the rotor salient pole that starts excitation of the stator winding based on the applied voltage or current.

Further, a step function signal generating circuit for generating a step function signal, a stator winding connected to a power source via a resistor that defines a time constant during transient response, and a voltage applied from the power source are A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. Corresponding to the detected voltage or detected current and the rotor salient pole position detected in the stator winding of the phase being excited before the phase being excited by the inductance detecting circuit and the inductance detecting circuit. And a rotational position detection circuit that detects the position of the rotor salient pole based on a predetermined voltage or current.

Further, in a rotor position detecting device of a sensorless motor driven by a drive circuit including a switch for turning on and off a current for exciting the stator winding, and a control circuit for controlling the switch, A step function signal generating circuit for generating a step function signal, a stator winding connected to a power source through a resistor that defines a time constant during transient response, a step function signal from the step function signal generating circuit, and the control An excitation signal for the stator winding from a circuit is input, and when the excitation signal is OFF, the step function signal is output to turn the switch ON and OFF.
By doing so, an AND circuit that applies the voltage applied from the power source as a step function voltage to the stator winding and the resistor, and a transient response generated in the stator winding and the resistor by the step function voltage Inductance detection circuit for detecting voltage or current at the time, based on the detection voltage or current detected by this inductance detection circuit and the voltage or current predetermined corresponding to the position of the rotor salient pole, And a rotational position detection circuit for detecting the position of the rotor salient poles.

The power source is a detection power source different from the sensorless motor power source.

Further, a commutator is provided between the detection power source and the stator winding.

Further , the number of times the step function signal is generated is
To drive the Nsare Sumo over data, a voltage in the stator winding
The step function voltage generated based on the step function signal is applied to the stator winding through a resistor that determines the time constant at the time of transient response , which is equal to or greater than the number of times of application. Then, based on the voltage or current during the transient response generated in the stator winding and the resistor by the step function voltage and the voltage or current predetermined corresponding to the position of the rotor salient pole, the rotation The position of a salient salient pole is detected, and the rotor position of a sensorless motor is detected.

[0025]

Further, a step function voltage generated based on the step function signal is applied to the stator winding through a resistor that determines a time constant during transient response, and the phase currently excited by the step function voltage is applied. Of the stator winding of the other phase and the resistance at the time of transient response generated in the resistance, and the stator winding based on the voltage or current predetermined corresponding to the position of the rotor salient pole. The position of the rotor salient pole at which the excitation of the wire is started is detected.

Further, a step function voltage generated based on the step function signal is applied to the stator winding through a resistor that defines a time constant during transient response, and the phase currently excited by the step function voltage is applied. Based on the voltage or current at the time of transient response generated in the stator winding and the resistance of the phase that was excited before and the voltage or current predetermined corresponding to the position of the rotor salient pole, The position of the rotor salient pole is detected.

Further, in the rotor position detecting method of the sensorless motor, in which the current is turned on and off by the switch operated by the excitation signal to excite and drive the stator winding,
When the excitation signal is OFF, out of the step function signal
The step function voltage generated by turning on and off the switch by applying a force is applied to the stator winding through a resistor that determines a time constant during transient response, and the step function voltage causes the stator winding and The position of the rotor salient pole is detected based on the voltage or current at the time of transient response generated in the resistance and the voltage or current predetermined corresponding to the position of the rotor salient pole.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, the first embodiment will be described with reference to the drawings. FIG. 1 is a configuration diagram of a sensorless motor drive device including a rotor position detection device according to the first embodiment, and illustrates one phase for ease of explanation. 2 is an operation waveform diagram of the rotor position detecting device 25, and FIG. 3 is a diagram showing a change in the inductance of the stator winding with respect to the rotation angle of the rotor salient poles. In FIG. 1, 8a is a transistor connected between one end of the stator winding 3 and the bus voltage 10, 8b is a transistor connected between one end of the stator winding 3 and GND, and 9a is one end of the stator winding 3. And a diode 9b connected between the other end of the stator winding 3 and the bus voltage 10, and 9b. Reference numeral 18 is a control circuit for turning on and off the transistor pair 8a and 8b by the stator winding excitation signal.

Reference numeral 25 is a rotor position detecting device for detecting the position of the rotor of the sensorless SR motor.
Of the resistor 13 connected in parallel with the transistor 8a between one end of the line 8 and the bus voltage 10, the step function signal generation circuit 17 for generating a step function signal, and the other end of the stator winding 3 connected in parallel with the transistor 8b. And resistance 13
A switching element that is connected in series with the stator winding 3 and is turned on / off based on the step function signal output from the step function signal generation circuit 17, and applies the bus voltage 10 to the stator winding as a step function voltage. Output from the inductance detection circuit 16 and the inductance detection circuit 16 which are connected from the connection point of the transistor 14, the resistor 13 and the stator winding 3 and which are detected as a voltage corresponding to the inductance of the stator winding 3 by the step function voltage. The rotational position detection circuit 15 outputs a signal indicating the position of the rotor salient pole 6 based on the generated voltage and the voltage corresponding to the preset position of the rotor salient pole 6.

Next, the operation of the entire sensorless SR motor drive device will be described with reference to FIG. Based on the stator winding excitation signal from the control circuit 18 for the stator winding 3 of any one of U, V and W phases, the transistor pair 8a, 8
When b is turned on, a current flows in the order of bus voltage 10 → transistor 8a → fixed winding 3 → transistor 8b. When the transistor pair 8a, 8b is turned off, a counter electromotive force is generated in the fixed winding 3. The energy of this counter electromotive force is regenerated through the diode 9a, the fixed winding 3, and the diode 9b. In this way, the exciting operation is sequentially performed on the windings U, V, W, and the sensorless SR motor is rotated. The timing of switching the transistor pair 8a and 8b between ON and OFF is controlled by the control circuit 18 in synchronization with the position of the stator salient pole 2 relative to the rotor salient pole 6 based on information from the rotor position detecting device 25.

The rotor position detecting device 25 includes the stator salient pole 2
The sensorless SR in which the inductance of the winding 3 of the stator salient pole 2 changes depending on the position of the rotor salient pole 6 with respect to
The characteristics of the motor are used.The position of the rotor salient pole with respect to the stator salient pole when exciting the stator winding is determined in advance, and the inductance of the stator winding at that time is calculated to determine the rotor salient pole. Detect the rotation angle of the pole. Then, the control circuit 18 changes the stator salient pole 2 according to the position of the rotor salient pole 6.
Is generated, and the stator salient pole 2 is excited in synchronization with the rotor salient pole 6.

Next, the operation of the rotor position detecting device 25 will be described with reference to FIGS. 2A is a step function signal waveform diagram of the step function signal generation circuit 17, and FIG. 2B is an input voltage waveform diagram of the inductance detection circuit 16. FIG. 3 shows the change in the inductance of the stator salient poles 2 with respect to the rotation angle of the rotor salient poles 6. In the figure, the rotation angles of the rotor salient poles 6, θ1, θ2, θ3, and θ4 are the stator salient poles. The figures a, b, c, and d showing the positional relationship between the pole 2 and the rotor salient pole 6 correspond.

As shown in FIG. 2A, the control circuit 18
When the output voltage of the step function signal generation circuit 17 is turned on based on the timing signal from
Is turned on, and a current flows from the bus voltage 10 to the transistor 14 through the resistor 13 and the stator winding 3. The voltage V input to the inductance detection circuit 16 by the current flowing at this time is V = Vb × exp (−R × t / L) (1) Here, Vb is the voltage value of the bus voltage 10 for driving the sensorless SR motor, R is the resistance value of the resistor 13 connected between the bus voltage 10 and the stator winding 3, and t
Is the elapsed time after the transistor 14 is turned on, and L is the inductance of the stator winding 3.

The voltage waveform of the voltage V input to the inductance detection circuit 16 at this time is as shown in FIG. Then, in FIG. 3, the stator salient pole 2 and the rotor salient pole 6 are
2 is close to the rotation angle θ1 and the inductance of the stator winding 3 is small, the value of the input voltage V sharply decreases as shown by the solid line in FIG. When the rotor salient poles 6 are close to the rotation angle θ3 facing each other and the inductance is large, it gradually decreases as shown by the alternate long and short dash line.

If the voltage Vb of the bus voltage 10, the resistance value R of the resistor 13 and the elapsed time t from when the transistor 14 is turned on are known from the equation (1), the inductance L of the stator winding 3 is calculated from V. Can be estimated.

As can be seen from FIG. 2, the voltage V when the inductance is large (dashed-dotted line) and the voltage V when the inductance is small (solid line) have a small difference between the respective voltages V when the elapsed time t is small. Since it is difficult, it is necessary to determine the elapsed time t so that the difference between the voltages V when the inductance is large (dashed-dotted line) and when the inductance is small (solid line) is large to facilitate detection. Normally, if the maximum value of the inductance of the stator winding 3 is about 10 mH and the resistance is about 1 kΩ, the elapsed time t is preferably about 4 μS. The elapsed time t is taken as the detection time, and the value of the voltage V at this time is taken as the transient voltage Vsens. If the positional relationship between the stator salient pole 2 and the rotor salient pole 6 with respect to the bus voltage 10 and the Vsens relationship at that time are obtained in advance, the stator salient pole 2 and the rotor salient pole 6 can be calculated from the value of Vsens. Since the positional relationship of can be estimated, the excitation can be easily started at a predetermined position.

For example, in FIG. 3, Vsens corresponding to the rotation angle θ1 at which the stator salient pole 2 and the rotor salient pole 6 are separated from each other.
Is Vs1 shown in FIG. 2, and the stator salient pole 2 and the rotor salient pole 6 are
When Vsens of the rotation angle θ3 facing each other is Vs2, when Vs1 is input to the inductance detection circuit 16, when the stator salient pole 2 and the rotor salient pole 6 are separated from each other at the rotation angle θ1 position. Therefore, when Vs2 is input to the inductance detection circuit 16, the rotation angle at which the stator salient pole 2 and the rotor salient pole 6 face each other is at the position of θ3. In order to simplify the detection circuit, it is desirable that the bus bar voltage be a constant voltage during the detection time.

The inductance detection circuit 16 outputs the voltage Vsens after the detection time from the input voltage V. The output voltage Vsens has a value corresponding to the position of the rotor salient pole 6 with respect to the stator salient pole 2. In the rotational position detection 15, the voltage Vsens output from the inductance detection circuit 16 and the preset stator salient pole 2 are set.
Is compared with the voltage corresponding to the positional relationship between the rotor salient pole 6 and the stator salient pole 2 and the rotor salient pole 6 which are set in advance.
The position corresponding to the position is detected and a position detection signal is sent to the control circuit 18.

Then, the control circuit 18 calculates the timing for exciting the stator salient poles from the sent position detection signal and outputs a signal for turning on or off the transistor pair 8a, 8b to the transistor pair 8a, 8b. Similarly, V phase and W phase are similarly performed.

As described above, the stator salient pole 2 is excited in synchronization with the position of the rotor salient pole 6 detected without providing the position detection sensor 11 for detecting the rotation angle of the rotary shaft 4 as in the conventional case. can do. Further, since it is not necessary to provide the position detection sensor 11, when the sensorless SR motor is put in a special space such as a compressor, the electric power for driving the position sensor other than the electric power for driving the sensorless SR motor is supplied. Moreover, it is not necessary to add terminals for taking out signals from the position sensor, and the compressor can be designed without being restricted by these terminals.

When the transistor 14 is turned on by the step function signal generating circuit 17, the magnitude of the step function current applied to the stator winding 2 is preferably such that the torque for rotating the rotor 5 is not affected. . Further, the step function signal generation circuit 17 turns on the transistor 14
It is also possible to output directly from the control circuit 18 because it is only turned off or N.

Embodiment 2. In order to obtain the excitation timing, the excitation start position and the excitation stop position are detected.
Position detection is required to be equal to or more than the number of times of excitation performed for one rotation of the R motor. The rotation speed of the stator salient poles is changing every moment due to load fluctuations. In order to improve the accuracy of the timing of exciting the stator winding, it is necessary to detect more rotor salient pole positions in consideration of this change. The present embodiment increases the number of steps of the step function signal as one of the methods for improving the rotor position accuracy.

The configuration diagram of the drive device of the sensorless motor provided with the rotor position detecting device of the present embodiment is shown in the first embodiment.
Since it is the same as that shown in FIG. 1, the operation will be described. As shown in FIG. 2 of the first embodiment, the position of the rotor is the inductance detection circuit 1 which has a predetermined detection time t after the voltage of the step function signal generation circuit 17 is turned on.
It detects from the input voltage of 6. After that, even if the output of the step function signal generation circuit 17 changes, it does not affect the rotor position detection. Therefore, after the inductance detecting circuit 16 detects the step function signal in order to increase the number of times, the transistor 14 can be turned off and on immediately by the signal of the step function generating circuit 17.
However, due to the inductance, when the current that is flowing is interrupted, a counter electromotive force is generated in the stator winding 3, and a regenerative current for consuming that energy flows.
If the step function voltage is applied again while the regenerative current is flowing, the accuracy of the position detection signal deteriorates as a result of the interference between the regenerative current and the current due to the step function voltage. Therefore, it is desirable to apply the step function voltage after the end of the regeneration period.

FIG. 4 shows an operation waveform diagram of the position detecting device 25. FIG. 4 (a) is a step function signal waveform diagram of the step function signal generating circuit 17, and FIG. 4 (b) is an inductance detecting circuit 1 diagram. 6 is an input voltage waveform diagram of No. 6; FIG. Figure 4
As shown in (a) and (b), when the signal of the step function signal generation circuit 17 is turned off after the detection time t and the input voltage of the inductance detection circuit 16 returns to the original voltage after the end of the regeneration time. Repeatedly turning on. The inductance detection circuit 16 outputs the voltage Vsens after the detection time t every time the voltage V is input, and detects the rotational position 15
The position of the rotor salient pole 6 is detected by. Therefore, the position of the rotor salient pole 6 is measured in detail. The regenerative time is
Since it is determined by the bus bar voltage 10, the resistance 13, the inductance of the stator winding 13, and the detection time, the value obtained in advance can be used.

By the above method, the accuracy of the timing of exciting the stator winding can be improved.

By outputting the signal of the step function signal generation circuit 17 in a pulse form, the detection time for voltage detection in the inductance detection circuit 16 and the ON time of the pulse signal of the step function signal generation circuit 17 are set. It may be used, and the circuit or the like for measuring the detection time in the inductance detection circuit 16 can be deleted. Further, the inductance detection circuit 16 generated by the pulse signal ON
It is detected that the magnitude of the input voltage to the switch has reached a voltage that corresponds to the preset positional relationship between the stator salient pole 2 and the rotor salient pole 6, and the excitation start or stop position is detected at that timing. You can also do it.

Embodiment 3. The configuration diagram of the drive device of the sensorless motor including the rotor position detection device of the present embodiment is the same as that of the first embodiment shown in FIG.
Since it is the same as, the operation will be described. Figure 5 (a)
[Fig. 4] is an operation waveform diagram showing a general relationship between a change in inductance of each phase and an excitation voltage applied to each phase. The timing of the applied voltage applied to each phase with respect to the inductance of each phase is actually as shown in the operation waveform diagram of FIG.
The voltage is applied in a slightly advanced form, and the rotor salient pole 6 rotation angle θ1 is set to the previous rotation angle θ0. However, in order to simplify the description, the lead angle is ignored in the description.

The inductance of each phase in FIG. 5A periodically changes depending on the rotation angle of the rotor salient pole 6. This cycle is 90 degrees when the stator salient pole 2 has 6 poles and the rotor salient pole 6 has 4 poles as in the sensorless SR motor of FIG. The deviation of the cycle of each phase is 30 degrees for each of the U, V, and W phases. In order to rotate the sensorless SR motor smoothly, the stator salient poles 2 must be excited at a position where torque is generated to rotate the rotor 5 in a fixed direction at all times. For example, when the U-phase winding is excited at θ1, the excitation of the U-phase winding must be stopped at θ3. Similarly, when the V-phase winding is excited at θ3, the excitation of the V-phase winding must be stopped at θ5. Thus, when the excitation of the U-phase winding is stopped, the excitation of the V-phase winding is started, and so on.

In the case of repeating in this manner, if the excitation start position of the phase to be excited next is known, it is easy to estimate the excitation stop position of the currently excited phase. That is,
When detecting the position of the rotor salient pole 6 with respect to the stator salient pole 2 in each phase, it is not necessary to detect both the excitation start position and the excitation stop position, and only the excitation start position needs to be detected. . That is, as shown in FIG.
The rotor position θ1 required for starting the U-phase excitation is detected, and the U-phase is excited. Next, the position θ3 of the rotor required to start the excitation of the V phase is detected, and the V phase is excited. Based on this, the U-phase excitation is stopped. By repeating this, the sensorless motor rotates.

That is, when the U-phase is excited, the rotational position detection circuit 15 is used to start the excitation with the V-phase and W-phase stator windings by the method as in the first and second embodiments. It suffices to perform only the position detection, and it is not necessary to detect the position where the U-phase excitation is stopped.

As described above, it is necessary to detect the excitation stop position when driving the stator winding by detecting only the excitation start position for detecting the rotor position for obtaining the excitation timing of the stator winding. The rotation position detection circuit can be simplified and the control circuit can be simplified.

Even in the overlap control in which the U-phase and V-phase are turned on at the same time, the U-phase excitation stop position can be easily obtained with reference to the V-phase excitation start position.

Fourth Embodiment The configuration diagram of the drive device of the sensorless motor including the rotor position detection device of the present embodiment is the same as that of the first embodiment shown in FIG.
Since it is the same as, the operation will be described. Each phase inductance as shown in Figure 5 of the third embodiment (a), the rotation
It periodically changes depending on the rotation angle of the salient salient pole 6 . The magnitude of this inductance is determined by the positions of the stator salient pole 2 and the rotor salient pole 6. If the magnitude of this inductance is known, the position of the rotor salient pole 6 can be estimated.

Now, when it is attempted to excite the stator winding 3 at θ0 in FIG. 6, if the detection voltage of the inductance detection circuit 16 with respect to the inductance at θ0 is obtained in advance, θ0 will be compared with that voltage. The position can be estimated. However, in the range of θY to θ1, the inductance is minimum and there is almost no change. If the position of the stator salient pole is estimated from the value of the inductance detected here, from θY to θ
It is very difficult to specify an arbitrary position within the range of 1.

Therefore, if detection is made at a position such as θX where there is a change in inductance with respect to the position of the rotor salient pole,
The position of the rotor salient pole 6 with respect to the inductance can be uniquely detected. That is, if the change in the inductance is detected in a range that decreases and the deviation from the excitation start position θ0 of the stator winding 3 is corrected from the rotation speed of the sensorless SR motor to start the excitation, the excitation start position is determined. Excitation can be started.

As described above, the change of the inductance changes periodically as shown in FIG. Therefore, it is difficult to estimate from the inductance detection voltage obtained by the step function voltage whether the value is within the rising range (θ2) or the decreasing range (θ4) shown in FIG. .

Therefore, in the present embodiment, the position of the rotor salient pole 6 is detected by making it possible to estimate whether the inductance detection voltage is in the rising range or the decreasing range.
FIG. 7 is an operation waveform diagram showing the operation of the fourth embodiment. 7A is a waveform diagram of the inductance of the stator winding with respect to the rotation angle of the rotor salient pole 6, FIG. 7B is a waveform diagram of the step function signal of the step function signal generation circuit 17, and FIG.
(C) is a waveform diagram of the inductance detection voltage, and the solid line shows the voltage drop from the bus voltage.

As shown in FIG. 7B, the step function signal is repeated a sufficient number of times to find a change in the inductance, and as shown in FIG. 7C, the inductance detection voltage obtained at a certain step function voltage. From the value and the inductance detection voltage value obtained by the next step function voltage, it can be estimated whether the inductance is in the decrease range or the increase range. That is, if the value obtained in the next step is larger than the value obtained by a certain step function, it is the rising range, and if it is smaller, it is the decreasing range.

As can be seen from FIG. 5 (a), when the inductance is in the decreasing range, for example, when the U-phase winding is excited (in the range of θ1 to θ3), the W that was excited before that is applied.
The phase inductance is decreasing. In FIG. 5A, when the W-phase excitation start position (θ5, actually, as described above, the excitation is started by advancing somewhat due to the inductance of the stator winding), the inductance is θ1 to θ1.
It may be detected within the range of 3. During this period, the U phase is excited. In other words, the timing of detection is such that if the inductance of the phase that is excited before the phase that is currently excited is detected, the inductance will decrease at that time, so it is necessary to compare the inductance detection voltages two or more times. Disappears. That is, by the rotational position detection circuit 15,
Based on the detected voltage detected in the stator winding 3 of the phase that was excited before the phase that is currently excited and the voltage that is predetermined corresponding to the position of the rotor salient pole 6, Pole 6
Is detected.

Actually, as described above, since the timing of exciting the stator winding is advanced due to the relationship of the inductance of the stator winding, the inductance of the previous phase before the currently excited phase is also increased. Can be detected.

By the above method, it is possible to detect with a simple circuit that only detects that a predetermined voltage has been reached.

Embodiment 5. FIG. 8 is a configuration diagram of a sensorless sensorless SR motor drive device including a rotor position detection device according to the fifth embodiment. In FIG. 1 of the first embodiment, resistor 13 is provided between bus voltage 10 and one end of stator winding 3. The power consumed here is (bus voltage-voltage drop of stator winding) 2 / resistance ... (2). The value of the resistor 13 has a time constant suitable for detecting the value of the inductance of the stator winding 3, and thus is usually about 1 kΩ. The voltage drop of the stator winding 3 at the time of detection takes a value of about 10% of the bus voltage 10. If the bus voltage is 200 V and the resistance is 1 kΩ, the power consumption is 30.
It will be about W. Further, since the busbar voltage 10 fluctuates in order to change the output of the sensorless SR motor, the parameter of the busbar voltage 10 is included in the voltage detection in the formula (1) of the first embodiment, and the detection method is It gets complicated.

Therefore, in order to solve this problem, the present embodiment is provided with a fixed power source 19 different from the bus voltage 10 as shown in FIG. By doing so, assuming that the voltage of the detection power supply 19 is a voltage for driving the transistor pair 8, for example, 15 V, the power consumption is about 0.2 W according to the equation (2).

As described above, since the power source for detection is different from the power source for sensorless motor, the power consumption of the resistor for detection can be reduced and the resistor itself can be inexpensive. . Further, by making the voltage of the detection power source 19 constant, the above equation (1) becomes a function of only the inductance, so that the detection method can be simplified.

Sixth Embodiment FIG. 9 is a configuration diagram of a sensorless motor drive device including a rotor position detection device according to the sixth embodiment. In FIG. 8 of the fifth embodiment, by using the detection power supply 19, the power consumption of the resistor can be reduced and the detection can be simplified. However, when the voltage of the detection power supply 19 is smaller than the bus voltage 10, A current may flow from the bus bar voltage 10 to the detection power supply 19. In order to eliminate the influence, it is necessary to take a strengthening measure such as increasing the capacity of the detection power supply 19.
Therefore, in the present embodiment, as shown in FIG.
In order to eliminate the influence of 0, a rectifier 20 for preventing a reverse current from flowing in the detection power supply 19 is provided. By doing so, a small capacity power supply for driving the transistor pair 8 can be used.

Embodiment 7. In FIG. 1 of the first embodiment and FIG. 8 of the fifth embodiment, when the sensorless SR motor is driven, the control circuit 18
The transistor pair 8 becomes O by the stator winding excitation signal from
N, a current flows through the stator winding 3. Further, in order to detect the rotational position, the transistor 14 is turned on and off by a signal from the step function signal generation circuit 14, and a current for position detection is passed through the stator winding 3. As described above, the transistors 8a, 8b, and 14 are provided to function as a switch for passing a current through the stator winding 3.

When the sensorless SR motor is driven, the transistor pair 8 is turned on by the stator winding excitation signal of the control circuit 18.
Therefore, the transistor 14 is turned on or off by the step function signal generation circuit 17. As described in the third embodiment, since it is not necessary to detect the excitation stop position, it does not matter whether the transistor 14 is ON or OFF while the transistor pair 8 is ON. At this time, the current flowing through the stator winding 3 flows out through the transistor 8b. When the transistor 14 is ON, current also flows through the transistor 14, but it only functions as a switch.
It does not affect the current flowing through.

When the sensorless SR motor is not driven, the transistor pair 8 is driven by the stator winding excitation signal of the control circuit 18.
Is OFF, and the transistor 14 is ON-OFF by the step function signal generation circuit 17. A current flows through the stator winding 3 when the transistor 14 is ON. The transistors 8b and 14 are
Since they are connected in parallel and only function as a switch that turns on and off, they can be integrated into either transistor. For example, the transistor 14 is eliminated and the transistor 8b is replaced by the transistor 1
It can be said that it also serves as the operation of 4.

In this embodiment, the transistor 8b also functions as the transistor 14. FIG. 10 is a configuration diagram of a sensorless motor drive device including a rotor position detection device according to the seventh embodiment, and FIG. 11 is an operation wave diagram showing the operation. In FIG. 10, the same or corresponding parts as those in FIG. 1 shown in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 21 is an AND circuit for ANDing the signal from the step function signal generation circuit 17 and the stator winding excitation signal from the control circuit 18.

With this configuration, when the sensorless SR motor is driven, the stator winding excitation signal from the control circuit 18 is turned on (Low-Volt), so that the transistor 8a is turned on. Since the stator winding excitation signal of the control circuit 18 input to the AND circuit 21 is turned on, the output is turned on regardless of the signal from the step function signal generation circuit 17, so that the transistor 8b is also turned on. Sensorless SR
Since the stator winding excitation signal from the control circuit 18 is OFF (High-Volt) when the motor is not driven, the transistor 8a is OFF. Since the stator winding excitation signal of the control circuit 18 input to the AND circuit 21 is OFF, the input signal from the step function signal generation circuit 17 is A as it is.
The output of the ND circuit 21 is output, and the signal of the step function signal generation circuit 17 is input to the transistor 8b to turn it on and off
To do. FIG. 11 shows the situation. Figure 11
(B) is an output signal of the step function signal generation circuit 17.

As described above, instead of separately providing the transistor 8b and the transistor 14 connected in parallel, either one can perform the same operation.

Eighth Embodiment FIG. 12 is a configuration diagram of a sensorless motor drive device including a rotor position detection device according to the eighth embodiment, and FIG. 13 is an operation wave diagram showing the operation. In FIG. 8 of the fifth embodiment, the detection power source 19 is connected in the order of the resistor 13, the stator winding 3 and the transistor 14, but in the present embodiment, the transistor 14 functions as a switch. Therefore, the connection order of the resistor 13 is changed to another power supply 19 → transistor 14 → stator winding 3 → resistor 13.

With such a structure, the position of the rotor salient pole 6 is detected as in the fourth embodiment. An operation waveform diagram at this time is shown in FIG. 13, FIG. 13A is a waveform diagram of the stator winding inductance with respect to the rotation angle of the rotor salient pole 6, and FIG. 13B is a step function signal generation circuit 17. FIG. 13C is a waveform diagram of the step function signal of FIG. However, in this case, FIG.
The signal input to the inductance detection circuit 16 as shown in (c) is opposite to that in FIG. 7 (c) of the fourth embodiment.

As described above, the detection method can be simplified by keeping the voltage of the power supply constant.

In the first to eighth embodiments,
The inductance detection circuit 16 detects the voltage at the transient response generated in the stator winding 3 and the resistor 13 by the step function voltage, and the rotation position detection circuit 15 detects the detection voltage detected by the inductance detection circuit 16 and the rotor protrusion. An example in which the position of the rotor salient pole is detected based on the voltage determined in advance corresponding to the position of the pole has been shown, but the inductance detection circuit 16 detects the current during transient response and detects the rotational position. The circuit 15 may detect the position of the rotor salient pole based on the detection current detected by the inductance detection circuit 16 and the current predetermined corresponding to the position of the rotor salient pole.

[0077]

Since the present invention is constructed as described above, it has the following effects.

A rotor position detecting device for a sensorless motor according to the present invention comprises a step function signal generating circuit for generating a step function signal, and a stator winding connected to a power source via a resistor that determines a time constant during transient response. A wire, a switch for applying a voltage applied from the power source to the stator winding and the resistor as a step function voltage based on the step function signal, and the stator winding and the resistor by the step function voltage. Inductance detection circuit that detects the voltage or current at the time of transient response that occurs, and the detection voltage or current detected by this inductance detection circuit and the voltage or current that is determined in advance corresponding to the rotor salient pole position. based on, and a rotation position detecting circuit for detecting the position of the rotor salient poles, wherein said step
The number of times the step function signal of the signal generation circuit is generated
Applying voltage to the stator winding to drive a less motor
Since it is the same as or more than the number of times , the simple circuit can be used without using the rotational position detection sensor.
The position of the stator salient pole with respect to the rotor salient pole of the sensorless motor can be detected by increasing the accuracy of the timing of exciting the stator winding .

[0079]

Further, a step function signal generating circuit for generating a step function signal, a stator winding connected to a power source via a resistor that defines a time constant during transient response, and a voltage applied from the power source are A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. Which is detected by the inductance detection circuit and the stator winding of the other phase of the phase currently being excited by the inductance detection circuit and the position of the rotor salient pole. And a rotational position detection circuit that detects the position of the rotor salient pole that starts the excitation of the stator winding based on the applied voltage or current. The detection circuit for the need to detect the excitation stop position at the time of driving of the stator winding is eliminated can be simplified.

Further, a step function signal generating circuit for generating a step function signal, a stator winding connected to a power source through a resistor that defines a time constant during transient response, and a voltage applied from the power source are A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. Corresponding to the detected voltage or detected current and the rotor salient pole position detected in the stator winding of the phase being excited before the phase being excited by the inductance detecting circuit and the inductance detecting circuit. And a rotational position detection circuit that detects the position of the rotor salient poles based on a predetermined voltage or current. By measuring the inductance of the stator winding which has been driven before the stator windings are moving, the detection circuit can be simplified as in the circuit only detects that has reached a predetermined voltage.

Further, in a rotor position detecting device for a sensorless motor driven by a drive circuit having a switch for turning on and off a current for exciting the stator winding, and a control circuit for controlling the switch, A step function signal generating circuit for generating a step function signal, a stator winding connected to a power source through a resistor that defines a time constant during transient response, a step function signal from the step function signal generating circuit, and the control An excitation signal for the stator winding from a circuit is input, and when the excitation signal is OFF, the step function signal is output to turn the switch ON and OFF.
By doing so, an AND circuit that applies the voltage applied from the power source as a step function voltage to the stator winding and the resistor, and a transient response generated in the stator winding and the resistor by the step function voltage Inductance detection circuit for detecting voltage or current at the time, based on the detection voltage or current detected by this inductance detection circuit and the voltage or current predetermined corresponding to the position of the rotor salient pole, Since a rotation position detection circuit that detects the position of the rotor salient pole is provided, it is possible to reduce expensive power transistor parts by combining the transistor for sensorless motor drive and the transistor for applying the step function voltage. it can.

Further, since the power source is the detection power source different from the sensorless motor power source, the power consumption of the detection resistor can be reduced, and the resistor itself can be inexpensive. Also, by keeping the voltage constant,
The detection method can be simplified.

Further, since the commutator is provided between the detection power supply and the stator winding, by suppressing the current from the stator winding, the power capacity of the detection power supply and the protection circuit can be made inexpensive. You can

The number of times the step function signal is generated is
Voltage to the stator windings to drive the
The step function voltage generated based on the step function signal is applied to the stator winding through a resistor that determines the time constant at the time of transient response , which is equal to or greater than the number of times of application. Then, based on the voltage or current during the transient response generated in the stator winding and the resistor by the step function voltage and the voltage or current predetermined corresponding to the position of the rotor salient pole, the rotation By detecting the position of the salient salient poles, the accuracy of the timing of exciting the stator winding can be improved by a simple circuit without using a rotational position detection sensor.
Gaité, it is possible to detect the position of the stator salient poles for the rotor poles of the sensor-less motor.

[0086]

Further, the step function voltage generated based on the step function signal is applied to the stator winding through the resistor that determines the time constant during the transient response, and the phase currently excited by the step function voltage is applied. Of the stator winding of the other phase and the resistance at the time of transient response generated in the resistance, and the stator winding based on the voltage or current predetermined corresponding to the position of the rotor salient pole. Since the position of the rotor salient pole that starts the excitation of the wire is detected, it is not necessary to detect the excitation stop position when the stator winding is driven, so that the detection circuit can be simplified.

Further, the step function voltage generated based on the step function signal is applied to the stator winding through a resistor that determines the time constant at the time of transient response, and the phase currently excited by the step function voltage is applied. Based on the voltage or current at the time of transient response generated in the stator winding and the resistance of the phase that was excited before and the voltage or current predetermined corresponding to the position of the rotor salient pole, Since the position of the rotor salient pole is detected, it can be simplified as a circuit that only detects that the detection circuit has reached a predetermined voltage.

[0089] Also, ON a current by switching the excitation signal, the rotor position detection method of a sensor-less motor is driven by exciting the stator windings to OFF, when the excitation signal is OFF, step function signal And output
A step function voltage generated by turning the switch ON and OFF is applied to the stator winding through a resistor that defines a time constant during transient response, and the step function voltage causes the step winding to apply to the stator winding and the resistor. Since the position of the rotor salient pole is detected based on the voltage or current at the time of the generated transient response and the voltage or current predetermined corresponding to the position of the rotor salient pole, a transistor for driving a sensorless motor is provided. By using only one transistor for applying the step function voltage, it is possible to reduce expensive power transistor parts.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a drive circuit of a sensorless motor including a rotor position detection device for a sensorless motor that is Embodiment 1 of the present invention.

FIG. 2 is a diagram showing operation waveforms of the rotor position detecting device for the sensorless motor according to the first embodiment of the present invention.

FIG. 3 is a diagram showing changes in the inductance of the stator winding with respect to the rotation angle of the rotor salient poles of the rotor position detecting device for a sensorless motor according to the first embodiment of the present invention.

FIG. 4 is a diagram showing operation waveforms of a rotor position detecting device for a sensorless motor that is Embodiment 2 of the present invention.

FIG. 5 is a diagram showing operation waveforms of a drive circuit of a sensorless motor including a rotor position detecting device for a sensorless motor according to a third embodiment of the present invention.

FIG. 6 is a diagram showing operation waveforms of a drive circuit for a sensorless motor including a rotor position detecting device for a sensorless motor according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing operation waveforms of a drive circuit of a sensorless motor including a rotor position detecting device for a sensorless motor according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing operation waveforms of a drive circuit of a sensorless motor including a rotor position detecting device for a sensorless motor according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing operation waveforms of a drive circuit for a sensorless motor including a rotor position detecting device for a sensorless motor according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing operation waveforms of a drive circuit for a sensorless motor including a rotor position detecting device for a sensorless motor according to a seventh embodiment of the present invention.

FIG. 11 is a diagram showing operation waveforms of a drive circuit of a sensorless motor including a rotor position detecting device for a sensorless motor according to a seventh embodiment of the present invention.

FIG. 12 is a diagram showing operation waveforms of a drive circuit for a sensorless motor including a rotor position detecting device for a sensorless motor according to an eighth embodiment of the present invention.

FIG. 13 is a diagram showing operation waveforms of a drive circuit for a sensorless motor including a rotor position detecting device for a sensorless motor according to an eighth embodiment of the present invention.

FIG. 14 is a configuration diagram of a conventional general sensorless motor and its drive circuit.

FIG. 15 is a diagram showing a positional relationship between a stator and a rotor of a general sensorless motor.

FIG. 16 is a diagram showing a change in inductance of a stator winding of a general sensorless motor.

[Explanation of symbols]

1 stator, 2 stator salient poles, 3 stator windings, 4 rotary shafts, 5 rotors, 6 rotor salient poles, 7 drive circuit, 8
a, 8b, 14 transistor, 9a, 9b, 20 diode, 10 bus voltage, 11 position detection sensor, 1
2 control circuit, 13 resistance, 15 rotation position detection circuit,
16 inductance detection circuit, 17 step function signal generation circuit, 18 control circuit, 19 detection power supply, 21
AND circuit, 25 rotor position detection device.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 10-14277 (JP, A) JP 6-189580 (JP, A) JP 7-177788 (JP, A) Special table 8- 501920 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02P 7/05 H02K 19/10

Claims (10)

(57) [Claims] 1. A step function signal generating circuit for generating a step function signal, a stator winding connected to a power source through a resistor that defines a time constant during transient response, a voltage applied from the power source, A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. The position of the rotor salient pole is determined based on the inductance detection circuit and the detection voltage or current detected by the inductance detection circuit and the voltage or current predetermined corresponding to the position of the rotor salient pole. A rotation position detecting circuit for detecting, and a generation time of the step function signal of the step signal generating circuit.
The number, in order to drive the sensorless Sumo over motor, the stator winding
The same as the number of times the voltage is applied to the
A rotor position detection device for a sensorless motor characterized by
Place 2. A step function signal generating circuit for generating a step function signal, a stator winding connected to a power source via a resistor that defines a time constant during transient response, a voltage applied from the power source, A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. And a detection voltage or current detected on the stator winding of the other phase of the phase currently being excited by the inductance detection circuit and the position of the rotor salient pole. A rotational position detection circuit that detects the position of the rotor salient pole that starts excitation of the stator winding based on the applied voltage or current. Rotor position detecting apparatus of a sensor-less motor according to claim. 3. A step function signal generation circuit for generating a step function signal, a stator winding connected to a power source via a resistor that defines a time constant during transient response, a voltage applied from the power source, A switch applied to the stator winding and the resistor as a step function voltage based on a step function signal, and a voltage or current at a transient response generated in the stator winding and the resistor by the step function voltage is detected. Corresponding to the detected voltage or detected current and the rotor salient pole position detected in the stator winding of the phase being excited before the phase being excited by the inductance detecting circuit. And a rotational position detection circuit for detecting the position of the rotor salient poles based on a predetermined voltage or current. Sumota rotor position detecting apparatus. 4. An electric current is applied to excite the stator winding.
In a rotor position detecting device for a sensorless motor driven by a drive circuit including a switch for turning N and OFF, and a control circuit for controlling the switch, a step function signal generating circuit for generating a step function signal and a transient response time A stator winding connected to a power source via a resistor that defines a time constant of, a step function signal from the step function signal generation circuit, and an excitation signal of the stator winding from the control circuit are input.
Then , when the excitation signal is OFF, the step function signal is output to turn the switch ON and OFF, and the voltage applied from the power source is used as the step function voltage to set the stator winding and the resistor. Applied to A
An ND circuit, an inductance detection circuit that detects a voltage or a current during a transient response generated in the stator winding and the resistor by the step function voltage, a detection voltage or a detection current detected by the inductance detection circuit, and a rotation A rotor position of a sensorless motor, comprising: a rotation position detection circuit that detects the position of the rotor salient pole based on a voltage or current predetermined corresponding to the position of the salient salient pole. Detection device. 5. The rotor position detecting device for a sensorless motor according to claim 1, wherein the power supply is a detection power supply different from the sensorless motor power supply. 6. The rotor position detecting device for a sensorless motor according to claim 5, further comprising a commutator provided between the detection power source and the stator winding. 7. A sensor for determining the number of times a step function signal is generated.
Applying voltage to the stator winding to drive a less motor
The same as the number of times that, or, more and more, by applying a pre-Symbol step function voltage generated on the basis of a step function signal in the stator winding via a resistor for determining the time constant of the transient response, the step function voltage The position of the rotor salient pole is determined based on the voltage or current at the time of transient response generated in the stator winding and the resistor and the voltage or current predetermined corresponding to the position of the rotor salient pole. A method for detecting a rotor position of a sensorless motor, which is characterized by detecting. 8. A step function voltage generated based on a step function signal is applied to a stator winding through a resistor that determines a time constant during transient response, and the phase currently excited by the step function voltage is applied. Of the stator winding of the other phase and the resistance at the time of transient response generated in the resistance, and the stator winding based on the voltage or current predetermined corresponding to the position of the rotor salient pole. A rotor position detecting method for a sensorless motor, characterized in that the position of the rotor salient pole at which the excitation of the wire is started is detected. 9. A step function voltage generated based on a step function signal is applied to a stator winding through a resistor that defines a time constant during transient response, and the phase currently excited by the step function voltage is applied. Based on the voltage or current at the time of transient response generated in the stator winding and the resistance of the phase that was excited before and the voltage or current predetermined corresponding to the position of the rotor salient pole, A rotor position detecting method for a sensorless motor, comprising detecting the position of the salient rotor poles. 10. ON a current by switching the excitation signal, the rotor position detection method of a sensor-less motor is driven by exciting the stator windings to OFF, when the excitation signal is OFF, step function signal Out
The step function voltage generated by turning on and off the switch by applying a force is applied to the stator winding through a resistor that determines a time constant during transient response, and the step function voltage causes the stator winding and The position of the rotor salient poles is detected based on a voltage or current at a transient response generated in the resistance and a voltage or current predetermined corresponding to the position of the rotor salient poles. Method for detecting rotor position of sensorless motor.