Method for adjusting a differential resolver and a differential resolver

Abstract

To provide a differential resolver adjustment method and a differential resolver with which it is possible to suppress a decrease in the accuracy of position detection due to variation in the signal outputted from an excitation coil.SOLUTION: Provided is an adjustment method for a differential resolver, with reluctance between a resolver rotor and a resolver stator changing with the position of the resolver rotor, that detects a current change due to a reluctance change when AC power is supplied to the excitation coil of each phase, on the basis of a difference signal between a first output signal in N phase that is shifted by 360 [deg] / N (N=integer 2 or greater) each in accordance with the position of the resolver rotor relative to the resolver stator and a second output signal in opposite phase that is 180 degrees out of phase with the first output signal for each phase. This adjustment method includes: a first step for adjusting the AC component of a signal with the first output signal in N phase added so that it becomes approximately zero; and a second step for adjusting, after the first step, the AC component of a signal with the first and second output signals added so that it becomes approximately zero.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an adjustment method for a differential resolver and a differential resolver. [Background technology]

[0002] A differential resolver is known that is suitable for preventing erroneous detection by a rotation sensor when a moment load is applied (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-216073 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a differential resolver that detects position based on a difference signal between differential signals of multiple phases, if there is variation in the signal output from the excitation winding, the position detection accuracy may decrease.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a differential resolver and an adjustment method for a differential resolver that can suppress a decrease in position detection accuracy due to variations in the signal output from the excitation winding. [Means for solving the problem]

[0006] In order to achieve the above object, an adjustment method for a differential resolver according to one embodiment of the present disclosure is a method for adjusting a differential resolver in which a reluctance between a resolver rotor and a resolver stator changes depending on a position of the resolver rotor, and a current change due to a reluctance change when AC power is supplied to an excitation winding of each phase is detected based on a difference signal between first output signals of N phases shifted by 360 [deg] / N (N is an integer of 2 or more) depending on the position of the resolver rotor relative to the resolver stator, and a second output signal of an opposite phase that is inverted in phase with respect to the first output signal for each phase, the method including a first step of adjusting a signal obtained by adding up the first output signals of N phases so that an AC component of the signal is approximately zero, and a second step of adjusting, after the first step, so that an AC component of the signal obtained by adding up the first output signal and the second output signal is approximately zero.

[0007] According to the above configuration, it is possible to suppress a decrease in the position detection accuracy caused by variations in the signal output from the excitation winding.

[0008] As a desirable aspect of the adjustment method for a differential resolver, in the first step, it is preferable that an input terminal of the second output signal of a differential amplifier circuit that outputs a difference signal between the first output signal and the second output signal is grounded, and the first output signal of N phases is added.

[0009] This makes it possible to absorb variations due to the differential amplifier circuit.

[0010] In order to achieve the above object, a differential resolver according to one embodiment of the present disclosure is a differential resolver in which a reluctance between a resolver rotor and a resolver stator changes depending on a position of the resolver rotor, and a current change due to a reluctance change when AC power is supplied to an excitation winding of each phase is detected based on a difference signal between a first output signal of N phases shifted by 360 [deg] / N (N is an integer of 2 or more) depending on the position of the resolver rotor relative to the resolver stator, and a second output signal of an opposite phase that is inverted in phase with respect to the first output signal for each phase, wherein a plurality of excitation windings are connected in series to a single-phase AC power source and are grounded via resistors, the first output signal is output from a connection point between the plurality of excitation windings and the resistor, a plurality of excitation windings are connected in series to the single-phase AC power source and are grounded via resistors, the second output signal is output from a connection point between the plurality of excitation windings and the resistor, and at least 2N-1 resistors of the 2N resistors are variable resistors.

[0011] According to the above configuration, it is possible to suppress a decrease in the position detection accuracy caused by variations in the signal output from the excitation winding, and also to make the adjustment work more efficient.

[0012] As a desirable embodiment of the differential resolver, all of the 2N resistors may be variable resistors.

[0013] In a preferred embodiment of the differential resolver, the differential resolver further comprises a differential amplifier circuit that outputs a difference signal between the first output signal and the second output signal.

[0014] As a preferred embodiment of the differential resolver, the differential resolver may further include a switch circuit that grounds an input terminal for the second output signal of the differential amplifier circuit. Effect of the Invention

[0015] According to the present disclosure, it is possible to provide a differential resolver and an adjustment method for a differential resolver that can suppress a decrease in position detection accuracy caused by variations in the signal output from the excitation winding. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a vertical cross-sectional view of a motor to which a differential resolver according to a first embodiment is applied. [Diagram 2] FIG. 2 is a cross-sectional view of the differential resolver according to the first embodiment. [Diagram 3] FIG. 3 is a circuit diagram showing a circuit configuration of the differential resolver according to the first embodiment. [Figure 4A] FIG. 4A is a diagram showing an example of the waveform of the first A-phase output signal. [Figure 4B] FIG. 4B is a diagram showing an example of the waveform of the 1B-phase output signal. [Figure 4C] FIG. 4C is a diagram showing an example of the waveform of the first C-phase output signal. [Figure 5A] FIG. 5A is a diagram illustrating a first procedure of the adjustment method for the differential resolver according to the first embodiment. [Figure 5B] FIG. 5B is a diagram illustrating a first procedure of the adjustment method for the differential resolver according to the first embodiment. [Figure 6A] FIG. 6A is a diagram illustrating a second procedure of the adjustment method for the differential resolver according to the first embodiment. [Figure 6B] FIG. 6B is a diagram illustrating a second procedure of the adjustment method for the differential resolver according to the first embodiment. [Figure 7] FIG. 7 is a circuit diagram showing a circuit configuration of a differential resolver according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a mode for carrying out the invention (hereinafter, referred to as an embodiment) will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiment. Furthermore, the components in the following embodiment include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiment can be appropriately combined.

[0018] (Embodiment 1) Fig. 1 is a vertical cross-sectional view of a motor to which a differential resolver according to embodiment 1 is applied. As shown in Fig. 1, motor 100 is configured to include stator 22, which is a stationary part, rotor 12, which is a rotor, cross roller bearing 14 interposed between rotor 12 and stator 22 to rotatably support rotor 12, motor section 16 that imparts rotational torque to rotor 12, and resolver 30 that detects the rotational angular position of rotor 12. Here, resolver 30, cross roller bearing 14, and motor section 16 are arranged on the same radial plane in that order from the radially inner side.

[0019] The stator 22 is formed with an annular inner wall body 22a protruding axially upward (upward in FIG. 1), and an annular outer wall body 22b protruding axially upward is formed radially outward from the inner wall body 22a. Meanwhile, the rotor 12 is formed with an annular inner wall body 12a protruding axially downward (downward in FIG. 1), and an annular outer wall body 12b protruding axially downward is formed radially outward from the inner wall body 12a. The stator 22 and the rotor 12 are arranged straddling each other such that the inner wall body 22a of the stator 22 is located between the inner wall body 12a and the outer wall body 12b of the rotor 12, and the outer wall body 12b of the rotor 12 is located between the inner wall body 22a and the outer wall body 22b of the stator 22.

[0020] The cross roller bearing 14 is configured to have an inner ring 14a, an outer ring 14b, and a number of cross rollers (rollers) 14c that are rotatably disposed between the inner ring 14a and the outer ring 14b. The cross rollers 14c are substantially circular with a diameter slightly larger than their length, and the even-numbered rotation axes on the orbit and the odd-numbered rotation axes on the orbit are inclined at 90° to each other.

[0021] The inner ring 14a is fixed by having its lower surface bonded to the upper surface of the inner wall body 22a of the stator 22. The outer ring 14b is fixed by having its upper surface bonded to the lower surface of the outer wall body 12b of the rotor 12.

[0022] The stator 22 is fixed to a fixed plate 24 by bolts 24a, and the rotor 12 is fitted onto the outer circumferential surface of the output shaft.

[0023] The motor section 16 is configured to include a permanent magnet 16a and a coil 16b arranged to face the permanent magnet 16a at a predetermined distance. The permanent magnet 16a is directly fixed to the outer circumferential surface of the outer ring 14b by being bonded thereto without using any other member. Meanwhile, the coil 16b is attached to the outer wall body 22b of the stator 22 by a bolt 16c.

[0024] The resolver 30 detects the position of the motor 100. The resolver 30 is an outer rotor type differential resolver including a resolver rotor 18 made of a hollow annular laminated core, and a resolver stator 20 arranged opposite the resolver rotor 18 at a predetermined interval and made of an annular laminated core with multiple stator poles formed at equal intervals in the circumferential direction.

[0025] The resolver rotors 18 of the two resolvers 30 are arranged at a small interval via a rotor spacer 42 and attached to the outer circumferential surface of the inner wall body 12a of the rotor 12 by bolts 18a. On the other hand, the resolver stators 20 of the two resolvers 30 are directly fixed to the inner ring 14a by being bonded to the inner circumferential surface of the inner ring 14a without any intervening member.

[0026] When current is applied to the coil 16b, the rotor 12 and the resolver rotor 18 rotate together, and a resolver stator 20 detects reactance changes, and a controller (not shown) controls the rotation speed and positioning.

[0027] Fig. 2 is a cross-sectional view of the differential resolver according to embodiment 1. Fig. 3 is a circuit diagram showing a circuit configuration of the differential resolver according to embodiment 1.

[0028] 2, on the inner peripheral surface of the resolver stator 20, first magnetic poles A11-A16, B11-B16, C11-C16 of N phases, for example, 18 poles of three phases, are formed at predetermined intervals in that order, and 18 poles of three phases, second magnetic poles A21-A26, B21-B26, C21-C26 are formed at intermediate positions between the first magnetic poles A11-A16, B11-B16, C11-C16, and these magnetic poles are arranged in the order of A11-21-B11-A21-C11-B21-A12-C22-. Each of the magnetic poles A11-C26 has three teeth TS1-TS3 formed on the end face on the inner peripheral surface side, and one excitation winding LA11-LC26 is wound in the center. Therefore, the magnetic poles at 180 degrees are in phase with each other.

[0029] The resolver rotor 18 has 150 slot teeth TR formed at equal intervals on its outer circumferential surface. Here, the pitch of the slot teeth TR of the resolver rotor 18 is such that, for example, if three adjacent teeth TR of the resolver rotor 18 coincide with the teeth TS1 to TS3 of the magnetic pole A11 of the resolver stator 20, the teeth TS1 to TS3 of the adjacent magnetic pole C21 are mechanically shifted in phase with the slot teeth TR of the resolver rotor 18 by 1 / 36 pitch.

[0030] 3, the excitation windings Li11-Li16 of the first magnetic poles i11-i16 (i=A, B, C) are connected in series, the excitation windings LA11-LC11 are connected to a single-phase AC power supply 63, and the excitation windings LA16-LC16 are grounded via resistors RA1-RC1, while the excitation windings Li21-Li26 of the remaining second magnetic poles i21-i26 are connected in series, the excitation windings LA21-LC21 are similarly connected to the single-phase AC power supply 63, and the excitation windings LA26-LC26 are grounded via resistors RA2-RC2. In this embodiment, the resistors RA1-RC1 and RA2-RC2 are variable resistors for signal adjustment, which will be described later.

[0031] Output terminals TA1, TB1, TC1 are provided from the connection points between the excitation windings LA16-LC16 and LA26-LC26 and the resistors RA1-RC1 and RA2-RC2, and output terminals TA2, TB2, TC2 are provided from which a first A-phase output signal A1, a first B-phase output signal B1, and a first C-phase output signal C1 are output in response to a current change due to a reluctance change between each magnetic pole and the slot teeth TR of the resolver rotor 18, and output terminals TA2, TB2, TC2 are provided from which a second A-phase output signal A2, a second B-phase output signal B2, and a second C-phase output signal C2 are output, and these are connected to three differential amplifier circuits 65A, 65B, 65C, each of which is composed of an operational amplifier.

[0032] Each of the differential amplifier circuits 65A, 65B, and 65C has an operational amplifier OP whose non-inverting input is connected to an output terminal TA1 via a resistor RI1 and grounded via a resistor RE, whose inverting input is connected to output terminals TA2, TB2, and TB2 via a resistor RI2, and a feedback resistor RF is inserted between the inverting input and the output. An output terminal TA is provided for outputting a difference signal between the first A-phase output signal A1 and the second A-phase output signal A2 input to the differential amplifier circuit 65A, an output terminal TB is provided for outputting a difference signal between the first B-phase output signal B1 and the second B-phase output signal B2 input to the differential amplifier circuit 65B, and an output terminal TC is provided for outputting a difference signal between the first C-phase output signal C1 and the second C-phase output signal C2 input to the differential amplifier circuit 65C.

[0033] A three-phase AC voltage corresponding to the excitation current output from these differential amplifier circuits 65A, 65B, 65C is supplied to a phase conversion circuit 66 which converts the three phases into two phases, and the two-phase signal output from the phase conversion circuit 66 is supplied to a signal processing circuit 67.

[0034] Fig. 4A is a diagram showing an example of the waveform of a 1A-phase output signal, Fig. 4B is a diagram showing an example of the waveform of a 1B-phase output signal, and Fig. 4C is a diagram showing an example of the waveform of a 1C-phase output signal.

[0035] As shown in FIG. 4A, FIG. 4B, and FIG. 4C, the 1i-th (i=A, B, C)-phase output signal i1 has a waveform in which the AC waveform of the single-phase AC power supply 63 shown by the solid line is superimposed on an approximately sine wave signal (AC signal) corresponding to a current change due to a reluctance change between each magnetic pole and the slot tooth TR of the resolver rotor 18. Here, the approximately sine wave signal specifically has a waveform shape that closely resembles an ideal sine waveform, for example, when the motor 100 is rotating at a constant speed. The approximately sine wave signal appears as an envelope of the AC waveform of the single-phase AC power supply 63 shown by the solid line. Moreover, the 1B-phase output signal B1 is a signal delayed by 120 [deg] of the approximately sine wave signal with respect to the 1A-phase output signal A1. Moreover, the 1C-phase output signal C1 is a signal delayed by 240 [deg] of the approximately sine wave signal with respect to the 1A-phase output signal A1. That is, the 1i-phase output signal i1 (i=A, B, C) is shifted by 360 [deg] / 3 (=120 [deg]) depending on the position of the resolver rotor 18 relative to the resolver stator 20.

[0036] On the other hand, the 2i-phase (i=A, B, C) output signal i2 is an inverted phase signal of the approximately sine wave signal of the 1i-phase output signal superimposed with the AC waveform of the single-phase AC power supply 63. As a result, the 2B-phase output signal B2 is an approximately sine wave signal delayed by 120 [deg] from the 2A-phase output signal A2. Also, the 2C-phase output signal C2 is an approximately sine wave signal delayed by 240 [deg] from the 2A-phase output signal A2.

[0037] When variations occur in the approximately sine wave signals of the 1st-phase A output signal A1, the 1st-phase B output signal B1, the 1st-phase C output signal C1, the 2nd-phase A output signal A2, the 2nd-phase B output signal B2, and the 2nd-phase C output signal C2, the position detection accuracy may be reduced. Examples of factors that cause variations in the approximately sine wave signals of the 1st-phase A output signal A1, the 1st-phase B output signal B1, the 1st-phase C output signal C1, the 2nd-phase A output signal A2, the 2nd-phase B output signal B2, and the 2nd-phase C output signal C2 include variations in the excitation windings and variations in the resistances of the differential amplifier circuits 65A, 65B, and 65C.

[0038] In this embodiment, by adjusting the variable resistors RA1-RC1 and RA2-RC2 for signal adjustment, the variation of the approximately sinusoidal signals of the 1st A-phase output signal A1, the 1st B-phase output signal B1, the 1st C-phase output signal C1, the 2nd A-phase output signal A2, the 2nd B-phase output signal B2, and the 2nd C-phase output signal C2 is suppressed, and the position detection accuracy is improved. Hereinafter, a method for adjusting the differential resolver according to the first embodiment will be described.

[0039] 5A and 5B are diagrams illustrating a first procedure of the adjustment method for the differential resolver according to the first embodiment.

[0040] In this embodiment, first, the 1A-phase output signal A1, the 1B-phase output signal B1, and the 1C-phase output signal C1 are adjusted. The 1A-phase output signal A1, the 1B-phase output signal B1, and the 1C-phase output signal C1 can be expressed by the following formulas (1), (2), and (3), respectively. In the following formulas (1), (2), and (3), A indicates the DC component of the 1A-phase output signal A1, B indicates the DC component of the 1B-phase output signal B1, and C indicates the DC component of the 1C-phase output signal C1.

[0041] A1 = (A + sinθ) × sinωt (1)

[0042] B1={B+sin(θ-120)}×sinωt (2)

[0043] C1={C+sin(θ-240)}×sinωt (3)

[0044] The DC component A of the first A-phase output signal A1 can be adjusted by a resistor RA1. The DC component B of the first B-phase output signal B1 can be adjusted by a resistor RB1. The DC component C of the first C-phase output signal C1 can be adjusted by a resistor RC1.

[0045] When the DC component A of the 1st A-phase output signal A1, the DC component B of the 1st B-phase output signal B1, and the DC component C of the 1st C-phase output signal C1 satisfy the following formula (4), the following formula (5) is established, and as shown in FIG. 5A, the approximately sine wave signal component of the signal obtained by adding the 1st A-phase output signal A1, the 1st B-phase output signal B1, and the 1st C-phase output signal C1 becomes zero.

[0046] A=B=C (4)

[0047] A1+B1+C1=0 (5)

[0048] If the DC component A of the 1st phase A output signal A1, the DC component B of the 1st phase B output signal B1, and the DC component C of the 1st phase C output signal C1 do not satisfy the above formula (4), the following formula (6) is obtained, and as shown in Figure 5B, an approximately sinusoidal signal appears in the signal obtained by adding the 1st phase A output signal A1, the 1st phase B output signal B1, and the 1st phase C output signal C1.

[0049] A1+B1+C1≠0 (6)

[0050] In the first step of the adjustment method for the differential resolver according to the first embodiment, the output terminals TA2, TB2, and TC2 are grounded. As a result, the first A-phase output signal A1, the first B-phase output signal B1, and the first C-phase output signal C1 are output to the output terminals TA, TB, and TC, respectively. Then, the resistors RA1, RB1, and RC1 are adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first A-phase output signal A1, the first B-phase output signal B1, and the first C-phase output signal C1 output from the output terminals TA, TB, and TC is within a predetermined range Δv1. More preferably, the resistors RA1, RB1, and RC1 are adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first A-phase output signal A1, the first B-phase output signal B1, and the first C-phase output signal C1 is approximately zero.

[0051] In addition, in FIG. 3, an example is shown in which each switch circuit SWA, SWB, SWC that grounds the output terminals TA2, TB2, TC2 is provided in the resolver 30, but this is not limiting, and the output terminals TA2, TB2, TC2 may be grounded outside the resolver 30, such as an adjustment jig connected to the output terminals TA2, TB2, TC2.

[0052] 6A and 6B are diagrams illustrating a second procedure of the adjustment method for the differential resolver according to the first embodiment.

[0053] In this embodiment, following the first procedure, the second A-phase output signal A2, the second B-phase output signal B2, and the second C-phase output signal C2 are adjusted.

[0054] The approximately sine wave signals appearing in the envelopes of the second-phase A output signal A2, the second-phase B output signal B2, and the second-phase C output signal C2 are inverted phase signals with respect to the approximately sine wave signals appearing in the envelopes of the first-phase A output signal A1, the first-phase B output signal B1, and the first-phase C output signal C1, respectively.

[0055] The DC component A' of the second A-phase output signal A2 can be adjusted by a resistor RA2. The DC component B' of the second B-phase output signal B2 can be adjusted by a resistor RB2. The DC component C' of the second C-phase output signal C2 can be adjusted by a resistor RC2.

[0056] When the DC component A of the first A-phase output signal A1 and the DC component A' of the second A-phase output signal A2 satisfy the following equation (7), the following equation (8) is established, and as shown in FIG. 6A, the approximately sinusoidal signal component of the signal obtained by adding the first A-phase output signal A1 and the second A-phase output signal A2 becomes zero.

[0057] A=A' (7)

[0058] A1+A2=0 (8)

[0059] When the DC component A of the first A-phase output signal A1 and the DC component A' of the second A-phase output signal A2 do not satisfy the above equation (7), the following equation (9) is obtained, and as shown in Figure 6B, an approximately sinusoidal signal appears in the signal obtained by adding the first A-phase output signal A1 and the second A-phase output signal A2.

[0060] A1+A2≠0 (9)

[0061] In a second procedure of the method for adjusting the differential resolver according to the first embodiment, the resistor RA2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first A-phase output signal A1 output from the output terminal TA1 and the second A-phase output signal A2 output from the output terminal TA2 is within a predetermined range Δv2. More preferably, the resistor RA2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first A-phase output signal A1 and the second A-phase output signal A2 is approximately zero.

[0062] In a second step of the method for adjusting the differential resolver according to the first embodiment, the resistor RB2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first B-phase output signal B1 output from the output terminal TB1 and the second B-phase output signal B2 output from the output terminal TB2 is within a predetermined range Δv2. More preferably, the resistor RB2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding the first B-phase output signal B1 and the second B-phase output signal B2 is approximately zero.

[0063] In a second step of the method for adjusting the differential resolver according to the first embodiment, the resistor RC2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding together the first C-phase output signal C1 output from the output terminal TC1 and the second C-phase output signal C2 output from the output terminal TC2 is within a predetermined range Δv2. More preferably, the resistor RC2 is adjusted so that the approximately sine wave signal (AC signal) appearing in the envelope of the signal obtained by adding together the first C-phase output signal C1 and the second C-phase output signal C2 is approximately zero.

[0064] The first and second procedures of the adjustment method for the differential resolver according to the first embodiment described above can suppress a decrease in position detection accuracy caused by variations in the signals output from the excitation windings.

[0065] (Embodiment 2) 7 is a circuit diagram showing a circuit configuration of a differential resolver according to embodiment 2. In this embodiment, of the resistors RA1 to RC1 and the resistors RA2 to RC2, the resistor RB1 is a fixed resistor.

[0066] In the first step of the method for adjusting the differential resolver according to this embodiment, the output terminals TA2, TB2, and TC2 are grounded, and the resistors RA1 and RC1 are adjusted so that the approximately sinusoidal signal appearing in the envelope of the signal obtained by adding together the first A-phase output signal A1, the first B-phase output signal B1, and the first C-phase output signal C1 output from the output terminals TA, TB, and TC falls within a predetermined range Δv1. This makes it possible to make the adjustment work more efficient.

[0067] In the above-described embodiment, an example has been described in which the 1i-phase output signal i1 (i=A, B, C) is shifted by 360[deg] / 3 (=120[deg]) depending on the position of the resolver rotor 18 relative to the resolver stator 20, and the 2i-phase output signal i2 (i=A, B, C) is a reverse-phase signal whose phase is inverted with respect to the 1i-phase output signal i1. However, the present invention is not limited to this, and it is also possible to apply the present invention to a mode in which a current change due to a reluctance change when AC power is supplied to the excitation winding of each phase is detected based on a difference signal between N-phase first output signals shifted by 360[deg] / N (N is an integer of 2 or more) and a reverse-phase second output signal whose phase is inverted with respect to the first output signal for each phase.

[0068] The figures used above are conceptual diagrams for qualitatively explaining the present disclosure, and are not limited to these. The above-described embodiment is an example of a preferred embodiment of the present disclosure, but is not limited thereto, and various modifications can be made without departing from the scope of the present disclosure. [Explanation of symbols]

[0069] 30 Resolver 63 Single-phase AC power supply 65A, 65B, 65C Differential amplifier circuit 66 Phase conversion circuit 67 Signal Processing Circuit A1 1st phase A output signal A2 2nd A phase output signal B1 1B phase output signal B2 2nd B phase output signal C1 1st C phase output signal C2 2nd C phase output signal LA11~LA16,LA21~LA26,LB11~LB16,LB21~LB26,LC11~LC16,LC21~LC26 Excitation winding RA1, RB1, RC1, RA2, RB2, RC2 Resistors SWA, SWB, SWC Switch circuit TA, TB, TC output terminals TA1, TB1, TC1 output terminals TA2, TB2, TC2 output terminals 100 Motor

Claims

1. A method for adjusting a differential resolver, the method comprising: detecting a current change caused by a reluctance change between a resolver rotor and a resolver stator depending on a position of the resolver rotor, based on a difference signal between first output signals of N phases shifted by 360 [deg] / N (N is an integer of 2 or more) depending on a position of the resolver rotor with respect to the resolver stator, and a second output signal of a reverse phase inverted from the first output signal for each phase, when AC power is supplied to an excitation winding of each phase, the method comprising: a first step of adjusting an AC component of a signal obtained by adding up the first output signals of N phases so that the AC component becomes approximately zero; a second step of adjusting, for each phase after the first step, N signals obtained by adding the first output signal and the second output signal so that each of the AC components becomes approximately zero; having How to adjust a differential resolver.

2. In the first step, an input terminal of the second output signal of a differential amplifier circuit that outputs a difference signal between the first output signal and the second output signal is grounded, and the first output signals of N phases are added.

2. The method for adjusting a differential resolver according to claim 1.

3. The differential resolver comprises: a plurality of excitation windings are connected in series to a single-phase AC power supply and are grounded via a first resistor, and the first output signal is output from a connection point between the plurality of excitation windings and the first resistor; a plurality of excitation windings are connected in series to the single-phase AC power supply and are grounded via a second resistor, and the second output signal is output from a connection point between the plurality of excitation windings and the second resistor; In the first step, the first resistor is adjusted so that an AC component of a signal obtained by adding up the first output signals of N phases becomes approximately zero; In the second step, the second resistor is adjusted so that AC components of N signals obtained by adding the first output signal and the second output signal for each phase are each approximately zero.

3. A method for adjusting a differential resolver according to claim 1 or 2.

4. The differential resolver includes N first resistors and N second resistors which are variable resistors. The method for adjusting a differential resolver according to claim 3 .

5. The differential resolver includes N-1 first resistors and N second resistors which are variable resistors. The method for adjusting a differential resolver according to claim 3 .

6. The differential resolver is adjusted by the adjustment method of the differential resolver according to any one of claims 1 to 5. Differential resolver.

7. a differential resolver in which a reluctance between a resolver rotor and a resolver stator changes depending on a position of the resolver rotor, and a current change caused by a reluctance change when AC power is supplied to an excitation winding of each phase is detected based on a difference signal between first output signals of N phases shifted by 360 [deg] / N (N is an integer of 2 or more) depending on a position of the resolver rotor with respect to the resolver stator, and a second output signal of an opposite phase that is inverted in phase with respect to the first output signal for each phase, a plurality of excitation windings are connected in series to a single-phase AC power supply and are grounded via a resistor, and the first output signal is output from a connection point between the plurality of excitation windings and the resistor; a plurality of excitation windings are connected in series to the single-phase AC power supply and are grounded via a resistor, and the second output signal is output from a connection point between the plurality of excitation windings and the resistor; Among the 2N resistors, at least 2N-1 resistors are variable resistors; a differential amplifier circuit that outputs a difference signal between the first output signal and the second output signal; a switch circuit that grounds an input terminal of the second output signal of the differential amplifier circuit; Equipped with Differential resolver.

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