JP4780493B2 - Rotor position detection device and rotor position detection method - Google Patents

Description

  The present invention relates to a rotor position detecting device and a rotor position detecting method for obtaining an initial position of a rotor of a permanent magnet synchronous motor.

  Permanent magnet synchronous motors (hereinafter referred to as PMSM: Permanent Magnet Synchronous Motor) are widely used in the industry because of their excellent maintainability and high efficiency.

When driving the PMSM, it is necessary to obtain the absolute position of the rotor and perform accurate current control. In order to obtain the absolute position of the rotor, it is necessary to use a rotor position detector such as an encoder or resolver. It is common. In recent years, there are various problems such as manufacturing costs and the complexity of the configuration of the rotor position detector. Therefore, a method for obtaining the rotor position without using the rotor position detector has been proposed (for example, Patent Document 1).
JP-A-9-191698

  However, most of the conventional methods detect the rotor position during driving of PMSM, and no simple method has been proposed in the technology for detecting the initial position of the rotor when starting PMSM.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotor position detecting device and a rotor position detecting method that can easily detect an initial rotor position at the start of PMSM using a DC power source.

The present invention employs the following means in order to solve the above problems. The invention according to claim 1, a rotor position detector for detecting the initial position of the rotor of the permanent magnet synchronous motor driven by a DC power source and the inverter circuit, the direct current between the two terminals of the permanent magnet synchronous motor When the DC voltage of the power supply is applied and excited in the forward direction or the reverse direction, the first voltage induced in one of the two sets of two terminals including the other non-excited one terminal and the first voltage induced in the other a first comparing means for comparing a second voltage, wherein said permanent magnet synchronous motor is applied to the DC voltage between two terminals is excited in the positive direction and the reverse direction, the other de-energized when excited in the positive direction A second comparing means for comparing a third voltage induced between the two terminals including the first terminal and a fourth voltage induced between the two terminals when excited in the opposite direction; and the first voltage and the The magnitude relationship with the second voltage and the third voltage and the fourth voltage Storage means for storing induced electromotive force data indicating the initial position of the rotor corresponding to the magnitude relationship, comparison results by the first comparison means and the second comparison means, and the induced electromotive force stored in the storage means It is characterized by comprising initial position detecting means for collating power data and detecting the initial position of the rotor based on the collation result.

  According to a second aspect of the present invention, in the rotor position detecting device according to the first aspect, when the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction, the non-excited other one terminal is included. The first voltage induced to one of the two terminals of the set and the second voltage induced to the other are selected and output to the first comparison means, and the two terminals of the permanent magnet synchronous motor are forwardly connected. And when excited in the opposite direction and excited in the forward direction, it is induced between the two terminals when excited in the opposite direction to the third voltage induced between the two terminals including the other non-excited one terminal. The apparatus further comprises selection means for selecting the fourth voltage and outputting it to the second comparison means.

  According to a third aspect of the present invention, in the rotor position detecting device according to the first or second aspect, the first comparing means is a first two terminals among three sets of two terminals of the permanent magnet synchronous motor. Compare the fifth voltage induced to one of the two sets of two terminals including the other one terminal that is not excited and the sixth voltage induced to the other when the gap is excited in the forward or reverse direction. When the second two terminals are excited in the forward direction or the reverse direction, the seventh voltage induced in one of the two sets of two terminals including the other one terminal that is not excited and the second voltage induced in the other The ninth voltage induced to one of the two sets of two terminals including the other one terminal that is not excited when the third two terminals are excited in the forward or reverse direction. The second comparison means is connected between the first two terminals, between the second two terminals or When one pair of two terminals between the third two terminals is excited in the forward and reverse directions, when excited in the forward direction, it is induced between the two terminals including the other one terminal that is not excited. The eleventh voltage is compared with the twelfth voltage induced between two terminals including the other non-excited one terminal when excited in the reverse direction.

The invention according to claim 4, a rotor position detecting method for detecting an initial position of the rotor of the permanent magnet synchronous motor driven by a DC power source and the inverter circuit, the direct current between the two terminals of the permanent magnet synchronous motor When the DC voltage of the power supply is applied and excited in the forward direction or the reverse direction, the first voltage induced in one of the two sets of two terminals including the other non-excited one terminal and the first voltage induced in the other a first comparison step of comparing the second voltage, wherein said permanent magnet synchronous motor is applied to the DC voltage between two terminals is excited in the positive direction and the reverse direction, the other de-energized when excited in the positive direction A second comparison step of comparing a third voltage induced between the two terminals including the first terminal and a fourth voltage induced between the two terminals when excited in the opposite direction; and the first voltage and the Magnitude relationship with the second voltage and the third voltage with the first voltage The induced electromotive force data indicating the initial position of the rotor corresponding to the magnitude relationship with the voltage is compared with the comparison results of the first comparison step and the second comparison step, and based on the comparison result, the rotation And an initial position detecting step for detecting an initial position of the child.

  According to a fifth aspect of the present invention, in the rotor position detecting method according to the fourth aspect, when the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction, the other one terminal that is not excited is included. The first voltage induced on one side between the two terminals of the set and the second voltage induced on the other side are selected, and the two terminals of the permanent magnet synchronous motor are excited in the forward direction and the reverse direction. Selection for selecting the fourth voltage induced between the two terminals when excited in the opposite direction to the third voltage induced between the two terminals including the other non-excited one terminal when excited at It has a step.

  According to a sixth aspect of the present invention, in the rotor position detecting method according to the fourth or fifth aspect, the first comparing step includes a first two terminals among two sets of two terminals of the permanent magnet synchronous motor. Compare the fifth voltage induced to one of the two sets of two terminals including the other one terminal that is not excited and the sixth voltage induced to the other when the gap is excited in the forward or reverse direction. When the second two terminals are excited in the forward direction or the reverse direction, the seventh voltage induced in one of the two sets of two terminals including the other one terminal that is not excited and the second voltage induced in the other The ninth voltage induced to one of the two sets of two terminals including the other one terminal that is not excited when the third two terminals are excited in the forward or reverse direction. 10th voltage induced on the other side is compared, and the second comparison step is performed between the first two terminals and the second two terminals. Alternatively, when any one pair of two terminals between the third two terminals is excited in the forward direction and the reverse direction, induction is performed between the two terminals including the other one terminal that is not excited when excited in the forward direction. The eleventh voltage is compared with the twelfth voltage induced between two terminals including the other one terminal not excited when excited in the reverse direction.

According to the first aspect of the present invention, the first comparing means applies the DC voltage of the DC power source between the two terminals of the permanent magnet synchronous motor to excite it in the forward direction or the reverse direction. Comparing the voltage induced between two sets of two terminals including the terminal, the second comparing means applies a DC voltage between the two terminals of the permanent magnet synchronous motor and de-energizes when excited in the positive direction. The initial position detecting means compares the voltage induced between the two terminals including the other one terminal with the voltage induced between the two terminals when excited in the reverse direction, and the initial position detecting means stores the induced voltage stored in the storage means. Since the power data is compared with the comparison results of the first comparison means and the second comparison means, and the initial position of the rotor is detected based on the comparison results, the rotor initial time when the permanent magnet synchronous motor is started The position can be easily detected using a DC power supply .

  According to the second aspect of the present invention, the selection means induces between the two sets of two terminals including the other one terminal not excited when the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction. The selected voltage is selected and output to the first comparison means, and is opposite to the voltage induced between the two terminals including the other one terminal that is not excited when the permanent magnet synchronous motor is excited in the forward direction between the two terminals. Since the voltage induced between the two terminals is selected and output to the second comparison means when excited in the direction, the first and second comparison means compare the two voltages output from the selection means. Thus, a comparison result indicating the magnitude relationship between the voltages can be obtained.

  According to the invention of claim 3, since the first comparison means compares three sets of voltages and the second comparison means compares one set of voltages, it should be compared with the induced electromotive force data stored in the storage means. The comparison result can be obtained more easily and accurately.

According to the invention of claim 4, the same effect as that of claim 1 can be obtained.
According to the invention of claim 5, the same effect as that of claim 2 can be obtained.
According to the invention of claim 6, the same effect as that of claim 3 can be obtained.

  Hereinafter, a rotor position detection device and a rotor position detection method according to embodiments of the present invention will be described in detail with reference to the drawings.

  When excitation is performed between any two terminals of the three input terminals of a three-phase permanent magnet synchronous motor (hereinafter referred to as three-phase PMSM), two sets of two terminals including terminals of non-excited phases (non-excited phases) Transient voltage is generated between the armature windings. It has been confirmed by experiments that the magnitude of the transient voltage generated between the two terminals is closely related to the position of the rotor of the three-phase PMSM.

  The present invention compares the magnitude relationship of transient voltages generated between two sets of two terminals including a non-excited phase when any two of the three input terminals of the three-phase PMSM are excited. The rotor initial position of the three-phase PMSM is detected based on this comparison result.

  FIG. 1 is a block diagram illustrating a functional configuration of a rotor position detection device according to a first embodiment of the present invention and a drive circuit that drives a three-phase PMSM to be inspected. As shown in FIG. 1, the rotor position detection apparatus 1 according to the first embodiment of the present invention includes a signal selection unit 2, a voltage comparison unit 3 (first and second comparison units of the present invention), a storage unit 4, and An initial position detector 5 is provided. The drive circuit for driving the three-phase PMSM 7 to be inspected includes a DC power supply Vd, a smoothing capacitor C, and a motor drive inverter 6. The smoothing capacitor C can be omitted.

  The signal selection unit 2 is connected to the three terminals (U phase, V phase, W phase) of the three-phase PMSM7, and two of the voltages between UV, VW, and WU are selected by switching the switch. A voltage is selected and output to the input terminals IN1 and IN2 of the voltage comparison unit 3.

  The voltage comparison unit 3 applies a DC voltage between any two terminals of the three terminals of the three-phase PMSM 7 to excite in the forward direction or the reverse direction. The transient voltage induced in one of the two and the transient voltage induced in the other are input to the input terminals IN1 and IN2, and the two voltages are compared and the comparison result is output to the initial position detector 5.

  The voltage comparison unit 3 applies a DC voltage between the two terminals of the three-phase PMSM 7 to excite in the forward direction and excites in the opposite direction from the transient voltage induced between the two terminals including the non-excitation phase. Then, the transient voltage induced between the two terminals is input to the input terminals IN1 and IN2, and the two voltages are compared and the comparison result is output to the initial position detector 5.

  The storage unit 4 stores induced electromotive force data to be collated with the comparison result output from the voltage comparison unit 3. The induced electromotive force data is data indicating the initial position of the rotor corresponding to the magnitude relationship between the two voltages compared by the voltage comparison unit 3 (details will be described later).

  The initial position detection unit 5 controls the motor drive inverter 6, the signal selection unit 2, and the voltage comparison unit 3, and the comparison result compared by the voltage comparison unit 3 and the induced electromotive force data stored in the storage unit 4 Collation is performed, and the rotor initial position θ of the three-phase PMSM 7 is detected based on the collation result. The initial position detection unit 5 is composed of, for example, a microcomputer.

  FIG. 2 is a circuit diagram showing a driving circuit of the three-phase PMSM7. As shown in FIG. 2, the driving circuit of the three-phase PMSM 7 includes a DC power source Vd, a smoothing capacitor C, and a motor driving inverter 6. The driving inverter 6 includes switches UP, UN, VP, VN, WP. , WN, and diodes D1 to D6 connected in parallel to each switch. These switches are composed of switching elements such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and are on / off controlled by a control signal output from the initial position detector 5. The U-phase winding of the three-phase PMSM7 is connected between the switch UP and the switch UN, the V-phase winding is connected between the switch VP and the switch VN, and the W-phase winding is connected between the switch WP and the switch WN. Connected between.

  FIG. 3 is a diagram illustrating an example of the three-phase PMSM 7. As shown in FIG. 3, when the center line of the winding axis of the U-phase winding is the reference axis O and the reference axis O coincides with the center axis A of the N pole of the permanent magnet, the rotor initial position θ = 0 °. The rotor initial position θ is positive when the rotor rotates clockwise. In this embodiment, an outer rotor type three-phase PMSM 7 is used, but an inner rotor type three-phase PMSM may be used in the present invention.

FIG. 4 is a block diagram illustrating the signal selection unit 2 and the voltage comparison unit 3 according to the first embodiment of the present invention. As shown in FIG. 4, the signal selection unit 2 is connected to the U phase, the V phase, and the W phase of the three-phase PMSM 7 and includes switches S _UV , S _VW , and S _G. The switches S _UV , S _VW and S _G may be general switching elements.

Switch S _UV is common terminal a first end of the contact piece 21 is connected to the other end of the contact piece 21 is connected selectively switched terminal b, to c. The common terminal a is connected to the input terminal IN1 of the voltage comparison unit 3, and the selection terminals b and c are connected to the U phase and V phase of the three-phase PMSM 7, respectively.

Switch S _VW is common terminal d at one end of the contact piece 22 is connected to the other end of the contact piece 22 is connected selectively switched terminal e, the f. The common terminal d is connected to the input terminal IN2 of the voltage comparison unit 3, and the selection terminals e and f are connected to the V phase and W phase of the three-phase PMSM 7, respectively.

Switch S _G, the common terminal g one end of the contact piece 23 is connected to the other end of the contact piece 23 selects the terminal h, i, are connected switched j. The common terminal g is grounded, and the selection terminals h, i, and j are connected to the U phase, V phase, and W phase of the three-phase PMSM 7, respectively.

  The voltage comparison unit 3 includes input terminals IN1 and IN2, non-inverting amplifiers 31 and 32, inverting amplifiers 33 and 34, switches S1 to S4, peak hold circuits 35 and 36, a comparator 37, and an output terminal OUT. The non-inverting amplifier 31 and the inverting amplifier 33 are connected to the input terminal IN1, and the non-inverting amplifier 32 and the inverting amplifier 34 are connected to the input terminal IN2.

  In the switch S1, one end of the contact piece 38a is connected to the common terminal k, and the other end of the contact piece 38a is switched and connected to the selection terminals l and m. The common terminal k is connected to the selection terminal r of the switch S3 and the selection terminal u of the switch S4, and the selection terminals l and m are connected to the non-inverting amplifier 31 and the inverting amplifier 33, respectively.

  In the switch S2, one end of the contact piece 38b is connected to the common terminal n, and the other end of the contact piece 38b is switched and connected to the selection terminals o and p. The common terminal n is connected to the selection terminal v of the switch S4 and the selection terminal s of the switch S3, and the selection terminals o and p are connected to the non-inverting amplifier 32 and the inverting amplifier 34, respectively.

  In the switch S3, one end of the contact piece 39a is connected to the common terminal q, and the other end of the contact piece 39a is switched and connected to the selection terminals r and s. The common terminal q is connected to the peak hold circuit 35.

  In the switch S4, one end of the contact piece 39b is connected to the common terminal t, and the other end of the contact piece 39b is switched and connected to the selection terminals u and v. The common terminal t is connected to the peak hold circuit 36. The switches S1 to S4 may be general switching elements.

  The peak hold circuit 35 is connected to the comparator 37, holds the maximum value of the transient voltage input via the switch S 3, and outputs the maximum value of the transient voltage held by the control from the initial position detection unit 5 to the comparator 37. .

  The peak hold circuit 36 is connected to the comparator 37, holds the maximum value of the transient voltage input via the switch S 4, and outputs the maximum value of the transient voltage held by the control from the initial position detection unit 5 to the comparator 37. .

  The transient voltage maximum value held in the peak hold circuits 35 and 36 is reset by the control from the initial position detector 5.

  The voltage comparison unit 3 also removes electromagnetic noise between the non-inverting amplifier 31 and the inverting amplifier 33 and the input terminal IN1, and between the non-inverting amplifier 32 and the inverting amplifier 34 and the input terminal IN2. Low pass filters LPF1 and LPF2 are connected (not shown for simplicity). The low-pass filters LPF1 and LPF2 are, for example, those having a cutoff frequency of 4 kHz and can be omitted if the influence of electromagnetic noise can be ignored.

  The comparator 37 compares the maximum values of the two transient voltages output from the peak hold circuits 35 and 36 and outputs the comparison result from the output terminal OUT to the initial position detector 5.

  The initial position detection unit 5 is a control unit that controls each unit of the rotor position detection device 1, and the comparison result of the transient voltage maximum value output from the comparator 37 of the voltage comparison unit 3 is stored in the storage unit 4. The rotor initial position θ of the three-phase PMSM 7 is detected based on the collation result by collating with the induced electromotive force data.

(Principle of the present invention)
Here, the principle of the present invention will be described. In the following description, positive excitation is performed by applying a DC voltage of the DC power source Vd between the two terminals of the three-phase PMSM7 and causing a current to flow in the positive direction of the phase sequence (U → V, V → W, W → U). The flow of current in the reverse phase order (V → U, W → V, U → W) is called negative excitation. Here, as an example, a case where excitation is performed between the VWs of the three-phase PMSM7 will be described.

When the VW of the three-phase PMSM 7 is positively excited, a transient voltage is generated between two sets of two terminals (between UV and WU) including the U-phase terminal that is a non-excitation phase of the three-phase PMSM 7. This transient voltage is an induced electromotive force caused by a change in magnetic flux linked to the armature winding. Figure 5 is a diagram rotor of the three-phase PMSM7 is when a rotor initial position θ = 40 °, showing a waveform of a transient voltage waveform and the V-phase current I _V generated when positive excited between VW . As shown in FIG. 5, at the rotor initial position θ = 40 °, the maximum value of the voltage between UVs in the reflux mode (described later) | V _{UV (+)} | _max and the maximum value of the voltage between _WUs | V _{WU (+)} | _Max is in a relation of UV voltage | V _{UV (+)} | _max > WU voltage | V _{WU (+)} | _max .

Also, FIG. 6 is a rotor of the three-phase PMSM7 is, when a rotor initial position theta = 40 °, showing a waveform of a transient voltage waveform and the V-phase current I _V generated when negatively energized between VW FIG. As shown in FIG. 6, even when the negative excitation, positive exciting time as well as UV voltage _{| V UV (-) | max} > WU voltage _{| V WU (over) |} a relationship of _max. Further, as shown in FIGS. 5 and 6, at the rotor initial position θ = 40 °, the maximum voltage between UVs during VW positive excitation | V _{UV (+)} | _max (0.625 V) and VW negative excitation The maximum voltage between _UVs | V _{UV (−)} | _max (0.666 V ₎ is in a relationship of negative excitation voltage | V _{UV (−)} | _max > positive excitation voltage | V _{UV (+)} | _max. .

  In this way, when two terminals of the three-phase PMSM7 are excited by a DC power supply, a transient voltage is generated between the two sets of two terminals including the non-excitation phase, and the maximum value of the transient voltage generated between the two sets of two terminals. There is a size relationship. Further, there is a magnitude relationship between the maximum value of the transient voltage generated between the two terminals including the non-excitation phase during positive excitation and during negative excitation. These magnitude relationships vary depending on the rotor initial position θ of the three-phase PMSM 7.

  FIG. 7 shows the magnitude relationship of the maximum transient voltage generated between two sets of two terminals including the non-excited phase when positive excitation and negative excitation are performed between VW, WU, and UV, and the initial rotor position θ of the three-phase PMSM7. It is a figure which shows the relationship.

  The induced electromotive force data of the present invention is the magnitude relationship of the transient voltage generated between two sets of two terminals including the non-excited phase when the two terminals of the three-phase PMSM7 are positively excited and negatively excited as shown in FIG. Is a table of data in which the correspondence between the rotor and the rotor initial position θ is recorded.

  In the present invention, the rotor initial position θ of the three-phase PMSM 7 can be detected by comparing the comparison result by the voltage comparison unit 3 with the induced electromotive force data.

For example, as shown in FIG. 7, the comparison result by the voltage comparison unit 3 when positively exciting between VW is the voltage between UVs during positive excitation | V _{UV (+)} | _max > voltage between WUs during positive excitation | V _{WU. When (+)} | _max , it can be detected that the rotor initial position θ = 0 to 90 ° or 180 to 270 °. The rotor initial position information obtained here is a cycle of 180 °, and the polarity of the rotor magnet cannot be determined.

For this reason, in order to determine the polarity of the rotor magnet next, negative excitation is performed between VW, and the voltage between UV | V _{UV (+)} | _max during positive excitation and the voltage between _UV | V _{UV (−)} during negative excitation. | _Max is compared by the voltage comparison unit 3. When the comparison result is, for example, the voltage between UVs during positive excitation | V _{UV (+)} | _max > the voltage between WUs during negative excitation | V _{UV (−)} | _max , the rotor initial position θ = 180 to 270 °. It can be detected.

Then, positively excited between WU, positive excitation at UV voltage _{| V UV (+) | max} and positive excitation at VW voltage _{| V VW (+) |} comparison result between _max is, for example, the positive excitation time When the voltage between UVs | V _{UV (+)} | _max > voltage between VWs during positive excitation | V _{VW (+)} | _max , it is possible to detect that the rotor initial position θ = 210 to 270 °. .

Then, positively excited between UV, positive excitation at WU voltage _{| V WU (+) | max} and positive excitation at VW voltage _{| V VW (+) |} comparison result between _max is, for example, the positive excitation time When the voltage between WUs | V _{WU (+)} | _max > voltage between VWs during positive excitation | V _{VW (+)} | _max , it is possible to detect that the rotor initial position θ is 240 to 270 °. .

  That is, by comparing the comparison result obtained by the voltage comparison unit 3 with the induced electromotive force data shown in FIG. 7 at the time of positive excitation between VW, negative excitation between VW, positive excitation between WU, and positive excitation between UV, The rotor initial position θ can be detected with an accuracy of 30 °.

  Next, a more specific operation of the rotational position detection device according to the first embodiment of the present invention will be described in detail.

(1) Positive excitation between VW First, the initial position detector 5 gives a control signal for turning on the switches WN and VP of the motor drive inverter 6 (see FIG. 2) in order to positively excite VW of the three-phase PMSM7. Output. When the switches WN and VP are turned on, a direct current flows through a route of the direct current power supply Vd → the switch VP → the V phase winding → the W phase winding → the switch WN → the direct current power supply Vd (hereinafter referred to as an excitation mode).

  Next, the initial position detector 5 outputs a control signal for turning off the switch VP in order to end the excitation. When the switch VP is turned OFF, the current flowing in the winding is circulated through the path of the V-phase winding → W-phase winding → switch WN → diode D4 → V-phase winding (hereinafter referred to as reflux mode). When the recirculation is finished after a certain time, the initial position detector 5 outputs a control signal for turning off the switch WN.

Initial position detecting unit 5, in the reflux mode when the VW HazamaTadashi excitation, as shown in FIG. 4 connects the selected terminal c and the common terminal a of the switch S _UV signal selection section 2, a common switch S _VW connecting the selected terminal f to the terminal d, connects the selected terminal h and the common terminal g of the switch S _G.

  The initial position detection unit 5 includes a common terminal k and a selection terminal m of the switch S1, a common terminal n and a selection terminal o of the switch S2, a common terminal q and a selection terminal r of the switch S3, and a switch S4. The common terminal t and the selection terminal v are connected to each other.

When the switches of the signal selection unit 2 and the voltage comparison unit 3 are connected as described above, the transient voltage −V _{UV (+)} between the UVs input to the input terminal IN1 of the voltage comparison unit 3 is obtained by the inverting amplifier 33. The transient voltage kV _{UV (+)} that has been inverted and amplified k times is input to the peak hold circuit 35. The peak hold circuit 35 holds the maximum value k | V _{UV (+)} | _max of the voltage kV _{UV (+)} .

Similarly, the transient voltage V _{WU (+)} between WUs input to the input terminal IN 2 of the voltage comparison unit 3 is amplified k times by the non-inverting amplifier 32, and the transient voltage kV _{WU (+)} is _supplied to the peak hold circuit 36. Entered. The peak hold circuit 36 holds the maximum value k | V _{WU (+)} | _max of the voltage kV _{WU (+)} .

The maximum transient voltage values k | V _{UV (+)} | _max and k | V _{WU (+)} | _max held in the peak hold circuits 35 and 36 are output to the comparator 37 under the control of the initial position detector 5. . The comparator 37 compares k | V _{UV (+)} | _max with k | V _{WU (+)} | _max, and outputs the comparison result to the initial position detector 5 from the output terminal OUT.

(2) Negative excitation between VW Next, the initial position detector 5 controls the switches VN and WP of the motor drive inverter 6 (see FIG. 2) to negatively excite the VW of the three-phase PMSM 7. Is output. When the switches VN and WP are turned on, a DC current flows through a path of the DC power source Vd → the switch WP → the W phase winding → the V phase winding → the switch VN → the DC power source Vd.

  Next, the initial position detector 5 outputs a control signal for turning off the switch WP in order to end the excitation. When the switch WP is turned off, the current flowing in the winding is circulated through the path of W phase winding → V phase winding → switch VN → diode D6 → W phase winding. When the recirculation is completed after a certain time, the initial position detector 5 outputs a control signal for turning off the switch VN.

The initial position detection unit 5 connects the common terminal a and the selection terminal c of the switch _SUV of the signal selection unit 2 and the common terminal d and the selection terminal f of the switch S _VW in the reflux mode of the negative excitation between _VW. connect and connects the selected terminal h and the common terminal g of the switch S _G.

  The initial position detection unit 5 includes a common terminal k and a selection terminal m of the switch S1 of the voltage comparison unit 3, a common terminal n and a selection terminal o of the switch S2, a common terminal q and a selection terminal s of the switch S3, and a switch S4. The common terminal t and the selection terminal u are connected to each other.

When the switches of the signal selection unit 2 and the voltage comparison unit 3 are connected as described above, the transient voltage −V _{UV (−)} between the UVs input to the input terminal IN1 of the voltage comparison unit 3 is obtained by the inverting amplifier 33. Inverted and amplified k times, and the transient voltage kV _{UV (−)} is input to the peak hold circuit 36.

Here, the peak hold circuit 36 holds a transient voltage maximum value k | V _{WU (+)} | _max held during WW positive excitation, and the UV voltage k | When V _{UV (+)} | _max > WU voltage k | V _{WU (+)} | _max , the voltage between UV k during negative excitation k | V _{UV (−)} | _max > voltage between WUs during positive excitation k | V _Since it has been experimentally confirmed that _{WU (+)} | _max is _satisfied , the peak hold circuit 36 overwrites and holds the UV voltage k | V _{UV (−)} | _max during negative excitation.

In addition, when the voltage between UVs k | V _{UV (+)} | _max <the voltage between WUs k | V _{WU (+)} | _max at the time of positive excitation between VW, the voltage between UVs k | V _{UV (−)} during negative excitation. Since | _max <voltage WU during positive excitation k | V _{WU (+)} | _max has been confirmed by experiments, the peak hold circuit 36 is not overwritten. V _{WU (+)} | _max continues to be held.

Similarly, the transient voltage V _{WU (−)} between WUs input to the input terminal IN 2 of the voltage comparison unit 3 is amplified k times by the non-inverting amplifier 32, and the transient voltage kV _{WU (−)} is _supplied to the peak hold circuit 35. Entered.

Here, the peak hold circuit 35 holds the transient voltage maximum value k | V _{UV (+)} | _max between UV held at the time of positive excitation between VW, and the voltage between UV k | at the time of positive excitation between VW. When V _{UV (+)} | _max > WU voltage k | V _{WU (+)} | _max , the UV voltage during positive excitation k | V _{UV (+)} | _max > voltage between WUs during negative excitation k | V _Since it has been confirmed by experiments that _{WU (−)} | _max is _satisfied , the peak hold circuit 35 continues to hold the UV voltage k | V _{UV (+)} | _max during positive excitation without being overwritten.

In addition, UV voltage _k at the time of VW HazamaTadashi excitation _{| V UV (+) | max} <WU between the voltage _{k | V WU (+) |} case was _max, positive excitation during the UV voltage _{k | V UV (+)} | _max <negative excitation at WU voltage k _{| V WU (over) |} for it to be _max has been confirmed by experiments, WU voltage k in the negative excitation to the peak hold circuit 35 _{| V WU (over)} | _Max is overwritten and retained.

In other words, if the voltage between UV kVUV ₍₊₎ | _max > voltage between WU k | _{VWU (+)} | _max at the time of positive excitation between VW, after the negative excitation between VW, k | V _{UV (+)} | _max is held, and the peak hold circuit 36 holds k | V _{UV (−)} | _max .

In addition, when the voltage between UVs k | V _{UV (+)} | _max <the voltage between WUs k | V _{WU (+)} | _max at the time of positive excitation between VW, after the negative excitation between VW, the peak hold circuit 35 k | V _{WU (−)} | _max is held, and the peak hold circuit 36 holds k | V _{WU (+)} | _max .

  The comparator 37 compares the voltage held in the peak hold circuit 35 with the voltage held in the peak hold circuit 36 and outputs the comparison result to the initial position detector 5. The initial position detection unit 5 stores the comparison result in the storage unit 4 and then outputs a control signal for resetting the voltage held in the peak hold circuits 35 and 36.

  Next, the initial position detection unit 5 collates this comparison result with the induced electromotive force data shown in FIG. 7, so that θ = 0 to 90 °, 90 to 180 °, 180 to 270 °, 270 to 360 °. Detect that any of the

Therefore, the initial position detection unit 5 performs positive excitation and negative excitation between VW, the maximum value of UV voltage k | V _{UV (+)} | _max during positive excitation, and the maximum value of UV voltage during negative excitation. k | V _{UV (−)} | _max , maximum value of WU voltage during positive excitation k | V _{WU (+)} | _max , maximum value of WU voltage during negative excitation k | V _{WU (−)} | _max The rotor initial position θ of the three-phase PMSM 7 can be obtained with an accuracy of 90 ° by obtaining which voltage is the maximum voltage.

(3) Positive excitation between WUs Next, the initial position detection unit 5 controls the switches UN and WP of the motor drive inverter 6 (see FIG. 2) to positively excite the WUs of the three-phase PMSM7. Is output. When the switches UN and WP are turned on, a direct current flows through the path of the direct current power supply Vd → the switch WP → the W phase winding → the U phase winding → the switch UN → the direct current power supply Vd.

  Next, the initial position detector 5 outputs a control signal for turning off the switch WP in order to end the excitation. When the switch WP is turned off, the current flowing in the winding is returned through a path of W phase winding → U phase winding → switch UN → diode D6 → W phase winding. When the recirculation is completed after a certain time, the initial position detector 5 outputs a control signal for turning off the switch UN.

  When the WU of the three-phase PMSM7 is positively excited, a transient voltage is generated between two terminals (between UV and VW) including the V-phase terminal which is a non-excitation phase of the three-phase PMSM7.

Initial position detecting unit 5, in the reflux mode when the WU HazamaTadashi excited, and connects the selected terminal b and the common terminal a of the switch S _UV signal selector 2, a selection terminal f and the common terminal d of the switch S _VW connect and connects the selected terminal i and the common terminal g of the switch S _G.

  The initial position detection unit 5 includes a common terminal k and a selection terminal l of the switch S1 of the voltage comparison unit 3, a common terminal n and a selection terminal p of the switch S2, a common terminal q and a selection terminal r of the switch S3, and a switch S4. The common terminal t and the selection terminal v are connected to each other.

When the switches of the signal selection unit 2 and the voltage comparison unit 3 are connected as described above, the transient voltage V _{UV (+)} between UVs input to the input terminal IN1 of the voltage comparison unit 3 is obtained by the non-inverting amplifier 31. The voltage is amplified k times and the transient voltage kV _{UV (+)} is input to the peak hold circuit 35. The peak hold circuit 35 holds the maximum value k | V _{UV (+)} | _max of the voltage kV _{UV (+)} .

Similarly, the transient voltage −V _{VW (+)} between VWs input to the input terminal IN2 of the voltage comparison unit 3 is inverted by the inverting amplifier 34, and the transient voltage kV _{VW (+)} amplified k times becomes a peak. It is input to the hold circuit 36. The peak hold circuit 36 holds the maximum value k | V _{VW (+)} | _max of the voltage kV _{VW (+)} .

The maximum transient voltage values k | V _{UV (+)} | _max and k | V _{VW (+)} | _max held in the peak hold circuits 35 and 36 are output to the comparator 37 under the control of the initial position detector 5. . The comparator 37 compares k | V _{UV (+)} | _max with k | V _{VW (+)} | _max and outputs the comparison result to the initial position detector 5 from the output terminal OUT. The initial position detection unit 5 stores the comparison result in the storage unit 4 and then outputs a control signal for resetting the voltage held in the peak hold circuits 35 and 36.

  Next, the initial position detector 5 collates this comparison result with the induced electromotive force data shown in FIG. The rotor initial position θ of the three-phase PMSM 7 is further narrowed down based on the comparison result and the comparison result when the VW is positively excited and negatively excited. Here, when the rotor initial position θ is in the range of 0 to 30 °, 90 to 120 °, 180 to 210 °, and 270 to 300 °, the rotor initial position θ can be detected with an accuracy of 30 °. Yes, the initial position detection ends. When the rotor initial position θ is out of the above range, the rotor initial position θ can be detected with an accuracy of 60 °, and positive excitation is continued between the UVs.

(4) Positive Inter-UV Excitation Next, the initial position detector 5 sends a control signal for turning on the motor drive inverter 6 (see FIG. 2) switches VN and UP to positively excite the UV of the three-phase PMSM 7. Output. When the switches VN and UP are turned ON, a DC current flows through a path of the DC power source Vd → the switch UP → the U phase winding → the V phase winding → the switch VN → the DC power source Vd.

  Next, the initial position detector 5 outputs a control signal for turning off the switch UP in order to end the excitation. When the switch UP is turned OFF, the current flowing in the winding is circulated through the path of the U-phase winding → the V-phase winding → the switch VN → the diode D2 → the U-phase winding. When the recirculation is completed after a certain time, the initial position detector 5 outputs a control signal for turning off the switch VN.

  When the UV of the three-phase PMSM7 is positively excited, a transient voltage is generated between two terminals (between VW and WU) including the W-phase terminal which is a non-excitation phase of the three-phase PMSM7.

Initial position detecting unit 5, in the reflux mode when the UV HazamaTadashi excited, and connects the selected terminal b and the common terminal a of the switch S _UV signal selector 2, a selection terminal e and the common terminal d of the switch S _VW connect and connects the selected terminal j and the common terminal g of the switch S _G.

  The initial position detection unit 5 includes a common terminal k and a selection terminal m of the switch S1, a common terminal n and a selection terminal o of the switch S2, a common terminal q and a selection terminal r of the switch S3, and a switch S4. The common terminal t and the selection terminal v are connected to each other.

When the switches of the signal selection unit 2 and the voltage comparison unit 3 are connected as described above, the transient voltage −V _{WU (+)} between WUs input to the input terminal IN1 of the voltage comparison unit 3 is obtained by the inverting amplifier 33. The transient voltage kV _{WU (+)} that has been inverted and amplified k times is input to the peak hold circuit 35. The peak hold circuit 35 holds the maximum value k | V _{WU (+)} | _max of the voltage kV _{WU (+)} .

Similarly, the transient voltage V _{VW (+)} between VWs input to the input terminal IN 2 of the voltage comparison unit 3 is amplified k times by the non-inverting amplifier 32, and the transient voltage kV _{VW (+)} is supplied to the peak hold circuit 36. Entered. The peak hold circuit 36 holds the maximum value k | V _{VW (+)} | _max of the voltage kV _{VW (+)} .

The maximum transient voltage values k | V _{WU (+)} | _max and k | V _{VW (+)} | _max held in the peak hold circuits 35 and 36 are output to the comparator 37 under the control of the initial position detector 5. . The comparator 37 compares k | V _{WU (+)} | _max and k | V _{VW (+)} | _max, and outputs the comparison result to the initial position detector 5 from the output terminal OUT. The initial position detection unit 5 stores the comparison result in the storage unit 4 and then outputs a control signal for resetting the voltage held in the peak hold circuits 35 and 36.

  Next, the initial position detector 5 collates this comparison result with the induced electromotive force data shown in FIG. By further narrowing down the rotor initial position θ of the three-phase PMSM7 based on this comparison result, a comparison result when positive excitation and negative excitation are performed between VWs, and a comparison result when positive excitation is performed between WUs, The rotor initial position θ can be detected with an accuracy of 30 °.

Next, an example of the rotor position detection method realized by the rotor position detection apparatus according to the first embodiment of the present invention will be described in detail with reference to the flowchart shown in FIG. As shown in FIG. 8, first, positive excitation is performed between VW (step S1). At this time, the maximum value | V _{UV (+)} | _{max of} the transient voltage generated between _UVs is compared with the maximum value | V _{WU (+)} | _{max of} the transient voltage generated between _WUs (step S2). If the voltage between UVs | V _{UV (+)} | _max > the voltage between WUs | V _{WU (+)} | _max in step S2, the value of the voltage between UVs | V _{UV (+)} | _max is held (step S3). ).

Next, negative excitation is performed between VW (step S4). In this case, the maximum value of the transient voltage generated between UV negative excitation time between _{VW | V UV (-) |} max and retained VW HazamaTadashi excitation when the UV voltage _{| V UV (+) | max} and Compare (step S5). When the voltage between UVs at the time of positive excitation | V _{UV (+)} | _max > the voltage between UVs at the time of negative excitation | V _{UV (−)} | _max in step S5, the WU is positively excited (step S6). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{UV (+)} | _{max of} the transient voltage generated between _UV are compared (step S7). If the inter-VW voltage | V _{VW (+)} | _max > the inter-UV voltage | V _{UV (+)} | _max in step S7, it is detected that the rotor initial position θ = 180 to 210 ° (step S8). .

If the voltage between VWs | V _{VW (+)} | _max <the voltage between UVs | V _{UV (+)} | _max in step S7, the UV is positively excited (step S9). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{WU (+)} | _{max of} the transient voltage generated between _WU are compared (step S10). If the inter-VW voltage | V _{VW (+)} | _max > the inter-WU voltage | V _{WU (+)} | _max in step S10, it is detected that the rotor initial position θ = 210 to 240 ° (step S11). .

If the inter-VW voltage | V _{VW (+)} | _max <the inter-WU voltage | V _{WU (+)} | _max in step S10, it is detected that the rotor initial position θ = 240 to 270 ° (step S12). .

If it is determined in step S5 that the voltage between UVs during positive excitation | V _{UV (+)} | _max <the voltage between UVs during negative excitation | V _{UV (−)} | _max , the WU is positively excited (step S13). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{UV (+)} | _{max of} the transient voltage generated between _UV are compared (step S14). If the inter-VW voltage | V _{VW (+)} | _max > the inter-UV voltage | V _{UV (+)} | _max in step S14, it is detected that the rotor initial position θ = 0 to 30 ° (step S15). .

If the inter-VW voltage | V _{VW (+)} | _max <the inter-UV voltage | V _{UV (+)} | _max in step S14, the UV is positively excited (step S16). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{WU (+)} | _{max of} the transient voltage generated between _WU are compared (step S17). If the inter-VW voltage | V _{VW (+)} | _max > the inter-WU voltage | V _{WU (+)} | _max in step S17, it is detected that the rotor initial position θ = 30 to 60 ° (step S18). .

If the inter-VW voltage | V _{VW (+)} | _max <the inter-WU voltage | V _{WU (+)} | _max in step S17, it is detected that the rotor initial position θ is 60 to 90 ° (step S19). .

When the voltage between UVs | V _{UV (+)} | _max <the voltage between WUs | V _{WU (+)} | _max in step S2, the value of the voltage between WUs | V _{WU (+)} | _max is held (step S20). ).

Next, negative excitation is performed between VW (step S21). At this time, the maximum value of the transient voltage generated between WUs during negative excitation between VWs | V _{WU (−)} | _max and the inter-WU voltage during positive excitations between VWs | V _{WU (+)} | _max Compare (step S22). When the voltage between WUs during positive excitation | V _{WU (+)} | _max > the voltage between WUs during negative excitation | V _{WU (−)} | _max in step S22, the WU is positively excited (step S23). At this time, the maximum value | V _{UV (+)} | _{max of} the transient voltage generated between _UV and the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW are compared (step S24). If the voltage between UVs | V _{UV (+)} | _max > the voltage between VWs | V _{VW (+)} | _max in step S24, it is detected that the rotor initial position θ is 270 to 300 ° (step S25). .

If the voltage between UVs | V _{UV (+)} | _max <the voltage between VWs | V _{VW (+)} | _max in step S24, the UV is positively excited (step S26). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{WU (+)} | _{max of} the transient voltage generated between _WUs are compared (step S27). If the inter-VW voltage | V _{VW (+)} | _max > the inter-WU voltage | V _{WU (+)} | _max in step S27, it is detected that the rotor initial position θ is 330 to 360 ° (step S28). .

If the inter-VW voltage | V _{VW (+)} | _max <the inter-WU voltage | V _{WU (+)} | _max in step S27, it is detected that the rotor initial position θ = 300 to 330 ° (step S29). .

Positive excitation at WU voltage in step _{S22 | V WU (+) |} max < negative excitation at WU voltage _{| V WU (-) |} If a _max is a positive excitation between WU (step S30). At this time, the maximum value | V _{UV (+)} | _{max of} the transient voltage generated between _UV and the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW are compared (step S31). If the UV voltage | V _{UV (+)} | _max > VW voltage | V _{VW (+)} | _max in step S31, it is detected that the rotor initial position θ is 90 to 120 ° (step S32). .

If the UV voltage | V _{UV (+)} | _max <the VW voltage | V _{VW (+)} | _max in step S31, the UV is positively excited (step S33). At this time, the maximum value | V _{VW (+)} | _{max of} the transient voltage generated between _VW and the maximum value | V _{WU (+)} | _{max of} the transient voltage generated between _WU are compared (step S34). If the inter-VW voltage | V _{VW (+)} | _max > the inter-WU voltage | V _{WU (+)} | _max in step S34, it is detected that the rotor initial position θ = 150 to 180 ° (step S35). .

If the inter-VW voltage | V _{VW (+)} | _max <the inter-WU voltage | V _{WU (+)} | _max in step S34, it is detected that the rotor initial position θ is 120 to 150 ° (step S36). .

  FIG. 9 is a diagram showing changes in the voltage waveform of each phase and the rotation speed of the three-phase PMSM7 when the three-phase PMSM7 is started by obtaining the rotor initial position θ (θ = 40 °) of the three-phase PMSM7 according to the present invention. It is. As shown in FIG. 9, the rotor initial position θ is 47 ms from the start of detection to the end of detection, and it can be seen that the three-phase PMSM 7 is rotating normally.

  As described above, it has been experimentally confirmed that the three-phase PMSM can be started from an arbitrary rotor position by applying the present invention.

  As described above, the rotor position detection device and the rotor position detection method according to the first embodiment of the present invention apply a DC voltage between the two terminals of the three-phase PMSM 7 to excite the two terminals. The voltage comparison unit 3 compares the voltage induced between two sets of two terminals including the other non-excited one terminal, and other than non-excited when the two terminals of the three-phase PMSM7 are excited in the positive direction. The initial position detector 5 compares the voltage induced between the two terminals including the first terminal with the voltage induced between the two terminals when excited in the reverse direction. Since the electromotive force data and the comparison result by the voltage comparison unit 3 are collated, and the initial position of the rotor is detected based on the collation result, the initial rotor position θ at the start of the three-phase PMSM is determined as a DC power source. Can be easily detected.

  The procedure described in this embodiment is merely an example, and the present invention is not limited to the procedure shown in this embodiment. For example, the order of excitation between VWs, WUs, and UVs can be changed.

  Further, positive excitation and negative excitation are performed between VW, and positive excitation is performed between WU and UV. However, negative excitation may be performed between WU and UV. Further, the distance between the two terminals for positive excitation and negative excitation is not limited to between VW but may be between WU or UV. Moreover, it is good also as what carries out positive excitation and negative excitation each between VW, between WU, and UV.

In the present embodiment, positive and negative excitation is performed between VW, and the voltage between UVs | V _{UV (+)} | _max during positive excitation and the voltage between UVs during negative excitation | V _{UV (−)} | _max positive excitation time of WU voltage _{| V WU (+) | max,} negative excitation upon WU voltage _{| V WU (over) |} by becomes maximum voltage of the _max is obtained whether any voltage, three Although the rotor initial position θ of the phase PMSM7 is obtained with an accuracy of 90 °, the rotor initial position θ of the three-phase PMSM7 is obtained with an accuracy of 90 ° by obtaining which voltage is the minimum voltage. It may be a thing.

  Further, in this embodiment, the transient voltage in the reflux mode between UV, VW, and WU is compared by the voltage comparison unit 3, but each transient voltage in the excitation mode is compared by the voltage comparison unit 3. It may be a thing.

  The present invention can be used as a rotor position detection device and a rotor position detection method that can easily detect the rotor position of a permanent magnet synchronous motor.

It is a block diagram which shows the structure of the rotor position detection apparatus which concerns on Example 1 of this invention, and the drive circuit of a three-phase permanent magnet synchronous motor. It is a circuit diagram which shows the drive circuit of the three-phase permanent magnet synchronous motor which concerns on Example 1 of this invention. It is a figure which shows the three-phase permanent magnet synchronous motor which concerns on Example 1 of this invention. It is a block diagram which shows the signal selection part and voltage comparison part which concern on Example 1 of this invention. It is the figure which showed the transient voltage waveform which generate | occur | produces between UV and WU at the time of the positive excitation between VW (rotor initial position (theta) = 40 degrees). It is the figure which showed the transient voltage waveform which generate | occur | produces between UV and WU at the time of the negative excitation between VW (rotor initial position (theta) = 40 degrees). It is a figure which shows the induced electromotive force data of this invention. It is a flowchart which shows an example of the operation | movement which concerns on Example 1 of this invention. It is a figure which shows the voltage waveform of each phase when the three-phase permanent magnet synchronous motor is started using the rotor position detection apparatus based on Example 1 of this invention, and the rotational speed of a three-phase permanent magnet synchronous motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor position detection apparatus 2 Signal selection part 3 Voltage comparison part 4 Memory | storage part 5 Initial position detection part 6 Motor drive inverter 7 Three-phase PMSM
31, 32 Non-inverting amplifiers 33, 34 Inverting amplifiers 35, 36 Peak hold circuit 37 Comparator C Smoothing capacitor
D1~D6 diode _{S1~S4, S UV, S VW,} S G, UN, UP, VN, VP, WN, WP switch Vd DC power supply

Claims (6)

A rotor position detecting device for detecting an initial position of a rotor of a permanent magnet synchronous motor driven by a DC power source and an inverter circuit,
When the DC voltage of the DC power source is applied between the two terminals of the permanent magnet synchronous motor and excited in the forward or reverse direction, induction is performed to one of two sets of two terminals including the other one terminal that is not excited. A first comparing means for comparing the first voltage to the second voltage induced to the other;
Is the induced between two terminals including other first terminal of the non-energized when said permanent magnet synchronous motor is applied to the DC voltage between two terminals is excited in the positive direction and reverse direction, it is excited in the positive direction A second comparison means for comparing a third voltage with a fourth voltage induced between the two terminals when excited in the opposite direction to the third voltage;
Storage means for storing induced electromotive force data indicating an initial position of the rotor corresponding to a magnitude relation between the first voltage and the second voltage and a magnitude relation between the third voltage and the fourth voltage;
The comparison result by the first comparison unit and the second comparison unit is collated with the induced electromotive force data stored in the storage unit, and the initial position of the rotor is detected based on the collation result. Initial position detecting means;
A rotor position detecting device comprising:   When the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction, the first voltage induced to one of two sets of two terminals including the other one terminal not excited is induced to the other. The second voltage to be selected is output to the first comparison means, and the two terminals of the permanent magnet synchronous motor are excited in the forward direction and the reverse direction. Selection means for selecting the fourth voltage induced between the two terminals when excited in the opposite direction to the third voltage induced between the two terminals including one terminal and outputting the selected voltage to the second comparison means. The rotor position detecting device according to claim 1, further comprising: The first comparing means includes
One of the two sets of two terminals including the other non-excited one terminal when the first two terminals of the three sets of the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction. The second voltage including the other one terminal that is not excited when the second voltage is excited in the forward direction or the reverse direction by comparing the fifth voltage induced by the second voltage and the sixth voltage induced by the other voltage. When the seventh voltage induced in one of the two terminals of the second and the eighth voltage induced in the other are compared, and the third two terminals are excited in the forward direction or the reverse direction, Comparing the ninth voltage induced in one of two sets of two terminals including one terminal with the tenth voltage induced in the other;
The second comparing means includes
When exciting between the first two terminals, between the second two terminals, or between any one pair of the two terminals in the forward and reverse directions, when exciting in the forward direction Compare the eleventh voltage induced between the two terminals including the other non-excited terminal with the twelfth voltage induced between the two terminals including the other non-excited terminal when excited in the reverse direction. The rotor position detecting device according to claim 1 or 2, wherein A rotor position detection method for detecting an initial position of a rotor of a permanent magnet synchronous motor driven by a DC power source and an inverter circuit,
When the DC voltage of the DC power source is applied between the two terminals of the permanent magnet synchronous motor and excited in the forward or reverse direction, induction is performed to one of two sets of two terminals including the other one terminal that is not excited. A first comparing step for comparing the first voltage to the second voltage induced to the other;
Is the induced between two terminals including other first terminal of the non-energized when said permanent magnet synchronous motor is applied to the DC voltage between two terminals is excited in the positive direction and reverse direction, it is excited in the positive direction A second comparison step for comparing a third voltage with a fourth voltage induced between the two terminals when excited in the opposite direction;
Inductive electromotive force data indicating the initial position of the rotor corresponding to the magnitude relationship between the first voltage and the second voltage and the magnitude relationship between the third voltage and the fourth voltage, the first comparison step, and the An initial position detecting step of comparing the comparison result of the second comparison step and detecting the initial position of the rotor based on the comparison result;
A rotor position detection method comprising:   When the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction, the first voltage induced to one of two sets of two terminals including the other one terminal not excited is induced to the other. The second voltage is selected, the two terminals of the permanent magnet synchronous motor are excited in the forward direction and the reverse direction, and when excited in the forward direction, induction is performed between the two terminals including the other one terminal that is not excited. 5. The rotor position detecting method according to claim 4, further comprising a selection step of selecting the fourth voltage induced between the two terminals when excited in the direction opposite to the third voltage. The first comparison step includes
One of the two sets of two terminals including the other non-excited one terminal when the first two terminals of the three sets of the two terminals of the permanent magnet synchronous motor are excited in the forward direction or the reverse direction. The second voltage including the other one terminal that is not excited when the second voltage is excited in the forward direction or the reverse direction by comparing the fifth voltage induced by the second voltage and the sixth voltage induced by the other voltage. When the seventh voltage induced in one of the two terminals of the second and the eighth voltage induced in the other are compared, and the third two terminals are excited in the forward direction or the reverse direction, Comparing the ninth voltage induced in one of two sets of two terminals including one terminal with the tenth voltage induced in the other;
The second comparison step includes
When exciting between the first two terminals, between the second two terminals, or between any one pair of the two terminals in the forward and reverse directions, when exciting in the forward direction Compare the eleventh voltage induced between the two terminals including the other non-excited terminal with the twelfth voltage induced between the two terminals including the other non-excited terminal when excited in the reverse direction. 6. The rotor position detection method according to claim 4, wherein the rotor position is detected.

Images