CN102621396A - Method and device for measuring alternate and direct axis induction of permanent magnet synchronous motor - Google Patents

Abstract

The invention relates to a method and device for measuring alternate and direct axis induction of a permanent magnet synchronous motor, which are characterized in that any one phase winding of the permanent magnet synchronous motor is disconnected respectively, and the remaining two phase windings are electrified with a power frequency alternate current of a certain amplitude; and within a certain period, corresponding line voltage and line current are sampled at fixed time, and the line inductance as well as the alternate axis inductance and the direct axis inductance of the three-phase winding can be calculated according to the formula. The device for measuring alternate and direct axis induction of the permanent magnet synchronous motor is formed through the method for measuring alternate and direct axis induction of the permanent magnet synchronous motor, and comprises an isolation step-down transformer, an isolation sampling circuit, a controllable change-over switch, a single microcontroller, a liquid crystal display screen and a direct current stabilized power source. The method and device provided by the invention realize the purpose of automatically, quickly, and accurately measuring the alternate and direct axis inductance of the permanent magnet synchronous motor without any instrument, rotor positioning and manual intervention.

Description

Permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus

Technical field

The present invention relates to a kind of permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus, particularly relate to a kind of automatic measurement and be used for the permagnetic synchronous motor friendship axle inductance of vector controlled and the device of d-axis inductance, belong to machine field.

Background technology

The position-sensor-free permagnetic synchronous motor of vector controlled obtains application more and more widely in fields such as industry and household electrical appliances, and the core of its system's operation characteristic quality is the accuracy that depends on the ac-dc axis inductance parameters of motor.The method of testing that is used to measure magneto ac-dc axis inductance at present mainly contains voltage integration, direct damped method etc., but these methods all need rotate to rotor d-axis or hand over shaft position, in actual measurement; Because the influence in magnetic field that DC current produces; Rotor is difficult to arrive assigned address, and needs multiple instrument manual works such as voltage table, reometer, power meter and oscillograph to obtain test data, and proving installation is too complicated; Test duration is long, and measuring accuracy is difficult to guarantee.

Summary of the invention

To the deficiency of existing measuring method, the present invention provides a kind of any instrument and meter that need not, and need not the rotor location, and simple in structure, test is quick, the method and apparatus of automatic accurate measurement permagnetic synchronous motor ac-dc axis inductance.

Principle of work involved in the present invention is described below.

The sketch of the permagnetic synchronous motor of three phase winding Y-connections under phasor coordinate system is as shown in Figure 1, and according to the theory of permagnetic synchronous motor, the line inductance of three phase windings is distinguished as follows:

$L_{\mathrm{AB}}={3L}_A-{3L}_B\sin (2\mathrm{\θ}-\frac{\mathrm{\π}}{6})---\left(1\right)$

L _BC＝3L _A-3L _Bcos2θ(2)

$L_{\mathrm{CA}}={3L}_A+{3L}_B\sin (2\mathrm{\θ}+\frac{\mathrm{\π}}{6})---\left(3\right)$

L in the formula _ABe the constant portion in the stator winding phase inductance, L _BBe the amplitude of the part of the pulsation in the stator winding phase inductance, θ is the angle of permanent magnet and A phase winding axle.

Comprehensively (1), (2), (3) can be derived:

$L_A=\frac{L_{\mathrm{AB}}+L_{\mathrm{BC}}+L_{\mathrm{CA}}}{9}---\left(4\right)$

$L_B=\frac{\sqrt{{(L_{\mathrm{AB}}+L_{\mathrm{CA}}-L_{\mathrm{BC}})}^2+3{(L_{\mathrm{CA}}-L_{\mathrm{AB}})}^2}}{9}---\left(5\right)$

The ac-dc axis inductance that can obtain permagnetic synchronous motor according to (4), (5) is:

$L_d=\frac{L_{\mathrm{AB}}+L_{\mathrm{BC}}+L_{\mathrm{CA}}-\sqrt{{(L_{\mathrm{AB}}+L_{\mathrm{CA}}-L_{\mathrm{BC}})}^2+3{(L_{\mathrm{CA}}-L_{\mathrm{AB}})}^2}}{6}---\left(6\right)$

$L_q=\frac{L_{\mathrm{AB}}+L_{\mathrm{BC}}+L_{\mathrm{CA}}+\sqrt{{(L_{\mathrm{AB}}+L_{\mathrm{CA}}-L_{\mathrm{BC}})}^2+3{(L_{\mathrm{CA}}-L_{\mathrm{AB}})}^2}}{6}---\left(7\right)$

Can know that by (6), (7) formula analysis the ac-dc axis inductance of permagnetic synchronous motor does not comprise θ, promptly it doesn't matter with the position of p-m rotor.Therefore,,, just can obtain the ac-dc axis inductance of permagnetic synchronous motor, need not rotor is implemented to locate through certain calculating as long as energy measurement goes out the line inductance of permanent magnet machine rotor three phase windings at an arbitrary position the time.

If break off the C phase of motor, the industrial-frequency alternating current u that communicates certain amplitude for A, B two, the generation electric current is i, according to the voltage equation of motor, the line inductance of two phases of switching on is:

$L_{\mathrm{AB}}=\frac{u-\mathrm{i\; R}}{\frac{\mathrm{di}}{\mathrm{dt}}}---\left(8\right)$

Because the voltage that the motor windings resistance R produces can be ignored with respect to the voltage of winding electric kinetic potential, (8) formula can become so:

$L_{\mathrm{AB}}=\frac{\mathrm{udt}}{\mathrm{di}}---\left(9\right)$

If with electric current and voltage in the very little set time sampling (9), then (9) formula can be converted into:

$L_{\mathrm{AB}}=\frac{\mathrm{u\Δt}}{\mathrm{\Δi}}---\left(10\right)$

In like manner break off respectively A mutually with B mutually, to remaining two communicate same amplitude industrial-frequency alternating current u, also can calculate L according to (10) formula _BC, L _CA

According to above-mentioned inventive concept, the present invention adopts following technical proposals:

Permagnetic synchronous motor ac-dc axis inductance measurement method of the present invention; It is characterized in that: through breaking off any phase winding of permagnetic synchronous motor respectively; Give the industrial-frequency alternating current of the logical certain amplitude of residue two phase windings; In the regular hour,, calculate the line inductance of three phase windings and hand over axle inductance and d-axis inductance according to said formula with fixed sampling time sample corresponding line voltage and line current.

Use the permagnetic synchronous motor ac-dc axis inductance measurement device that permagnetic synchronous motor ac-dc axis inductance measurement method of the present invention constitutes; Comprise insulate step-down transformer, isolate sample circuit, controlled switch, single chip microcontroller, LCDs, D.C. regulated power supply; It is characterized in that: power frequency 220V alternating current is connected with controlled switch with the isolation sample circuit through insulate step-down transformer; The output signal of isolating sample circuit is connected to the analog to digital conversion pin of single chip microcontroller; Controlled switch is connected with terminal A, B, C; The control signal of single chip microcontroller is connected with controlled switch control end, and the output signal of single chip microcontroller is connected with LCDs, and 12V and 5V power supply that D.C. regulated power supply produces are delivered to controlled switch and single chip microcontroller respectively.

Described insulate step-down transformer adopts the unskilled labor frequency power transformer; Comprise primary and secondary; The mutual electrical isolation of primary and secondary; Elementaryly be electrically connected with the 220V industrial frequency AC, secondary L, N end respectively with two AC ends tandem of two AC ends of isolating sample circuit voltage sensor U1 and D.C. regulated power supply rectifier bridge heap D.

Described isolation sample circuit comprises voltage sensor U1 and current sensor U2; The V output terminal of U1 is connected with the analog to digital conversion pin P0.1 of single chip microcontroller U3; The I output terminal of U2 is connected with the analog to digital conversion pin P0.2 of single chip microcontroller; The input negative terminal IN-of U2 is connected with the secondary N end of insulate step-down transformer, the G end ground connection of U1, U2.

Described controlled switch comprises four relay K A, KB1, KB2, KC and four control triode Q1, Q2, Q3, Q4, and each relay is made up of two switch contacts and a control coil, and the secondary L of the left contact of relay K A, the left contact of KB1 and insulate step-down transformer holds tandem; The right side of KA is touched with terminal A and is connected; Supply permagnetic synchronous motor A phase winding end to connect, the input anode IN+ tandem of the left contact of relay K B2, KC, current sensor U2 is connected with terminal B after the right contact tandem of KB1, KB2; Supply permagnetic synchronous motor B phase winding end to connect; The right contact of KC is connected with lead-out terminal C, supplies permagnetic synchronous motor C phase winding end to connect, and the left end of KA control coil is connected with the collector of triode Q1; The left end of KB1 control coil is connected with the collector of triode Q2; The left end of KB2 control coil is connected with the collector of triode Q3, and the left end of KC control coil is connected with the collector of triode Q4, the right-hand member of KA, KB1, KB2, KC control coil and 12V tandem; The emitting stage of Q1, Q2, Q3, Q4 and ground tandem, Q1, Q2, Q3, Q4 ground level are connected with P2.0, P2.1, P2.2, the P2.3 of single chip microcontroller respectively.

Described single chip microcontroller adopts R8C/2L; Described display screen adopts 1206, and the P1.0 of single chip microcontroller, P1.1, P1.2, P1.3, P1.4, P1.5, P1.6, P1.7, P2.4, P2.5, P2.6 are connected with DB0, DB1, DB2, DB3, DB4, DB5, DB6, DB7, RS, R/W, the E of display screen respectively.

Described D.C. regulated power supply comprises rectifier bridge heap D, 12V regulator block U3,5V regulator block U4 and electrochemical capacitor C; The anodal V+ of rectifier bridge heap D, the positive pole of electrochemical capacitor C, the input end Vin tandem of 12V regulator block U3; The output terminal of 12V regulator block U3 is connected with the input end Vin of 5V regulator block U4; The output 5V voltage of 5V regulator block U4, the GND end tandem ground connection of the GND end of the negative pole V-of rectifier bridge heap D, the negative pole of electrochemical capacitor C, 12V regulator block U3,5V regulator block U4.

Permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus of the present invention; Utilize the break-make of single chip microcontroller pilot relay to pass to the industrial-frequency alternating current of certain amplitude only for respectively any two phase windings of permagnetic synchronous motor; In the regular hour, with fixed sampling time sampling its corresponding line voltage and line current, through demonstrating the ac-dc axis inductance of permagnetic synchronous motor after the simple calculations; Compare with background technology and to have realized need not any instrument; Need not the rotor location, need not manual intervention, automatically, fast, accurately demonstrate the purpose of the ac-dc axis inductance of permagnetic synchronous motor.

Description of drawings

Fig. 1 is the structure diagram of permagnetic synchronous motor under phasor coordinate system; A axle, B axle, C axle are respectively the winding axle of motor AA ' phase winding, BB ' phase winding, CC ' phase winding among the figure; N, S are for being installed in the rotor permanent magnetic steel, and d, q are the d-axis under the phasor coordinate system and hand over axle.

Fig. 2 is a block diagram of the present invention, among the figure: 1, insulate step-down transformer, 2, isolate sample circuit, 3, controlled switch, 4, single chip microcontroller, 5, LCDs, 6 D.C. regulated power supplies.

Fig. 3 is the system construction drawing of one embodiment of the present of invention.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment the present invention is described further.

Permagnetic synchronous motor ac-dc axis inductance measurement method of the present invention; Through breaking off any phase winding of permagnetic synchronous motor respectively; Give the industrial-frequency alternating current of the logical certain amplitude of residue two phase windings; In the regular hour,, calculate the line inductance of three phase windings and hand over axle inductance and d-axis inductance according to said formula with fixed sampling time sample corresponding line voltage and line current.

Referring to Fig. 2; Use the permagnetic synchronous motor ac-dc axis inductance measurement device that permagnetic synchronous motor ac-dc axis inductance measurement method of the present invention constitutes, comprise insulate step-down transformer 1, isolate sample circuit 2, controlled switch 3, single chip microcontroller 4, LCDs 5, D.C. regulated power supply 6; Power frequency 220V alternating current is connected with controlled switch 3 with isolation sample circuit 2 through insulate step-down transformer 1; The output signal of isolating sample circuit 2 is connected to the analog to digital conversion pin of single chip microcontroller 4; Controlled switch 3 is connected with terminal A, B, C respectively; The control signal of single chip microcontroller 4 is connected with controlled switch 3; The output signal of single chip microcontroller 4 is connected with LCDs 5, and 12V and 5V power supply that D.C. regulated power supply 6 produces are delivered to controlled switch and single chip microcontroller respectively.Insulate step-down transformer 1 adopts the unskilled labor frequency power transformer; Comprise primary and secondary; The mutual electrical isolation of primary and secondary; Elementaryly be electrically connected with the 220V industrial frequency AC, secondary L, N end respectively with two AC ends tandem of two AC ends of isolating sample circuit 2 voltage sensor U1 and D.C. regulated power supply 6 rectifier bridges heap D; Isolate sample circuit 2 and comprise voltage sensor U1 and current sensor U2; The V output terminal of U1 is connected with the analog to digital conversion pin P0.1 of the U3 of single chip microcontroller 4; The I output terminal of U2 is connected with the analog to digital conversion pin P0.2 of single chip microcontroller 4; The N end of 1 level of input negative terminal IN-and insulate step-down transformer of U2 is connected, the G end ground connection of U1, U2; Controlled switch 3 comprises four relay K A, KB1, KB2, KC and four control triode Q1, Q2, Q3, Q4, and each relay is made up of two switch contacts and a control coil, and the secondary L of the left contact of relay K A, the left contact of KB1 and insulate step-down transformer holds tandem; The right side of KA is touched with terminal A and is connected; Supply permagnetic synchronous motor A phase winding end to connect, the input anode IN+ tandem of the left contact of relay K B2, KC, current sensor U2 is connected with terminal B after the right contact tandem of KB1, KB2; Supply permagnetic synchronous motor B phase winding end to connect; The right contact of KC is connected with terminal C, supplies permagnetic synchronous motor C phase winding end to connect, and the left end of KA control coil is connected with the collector of triode Q1; The left end of KB1 control coil is connected with the collector of triode Q2; The left end of KB2 control coil is connected with the collector of triode Q3, and the left end of KC control coil is connected with the collector of triode Q4, the right-hand member of KA, KB1, KB2, KC control coil and 12V tandem; The emitting stage of Q1, Q2, Q3, Q4 and ground tandem, Q1, Q2, Q3, Q4 ground level are connected with P2.0, P2.1, P2.2, the P2.3 of single chip microcontroller 4 respectively; Single chip microcontroller 4 adopts R8C/2L; Display screen 5 adopts 1206, and the P1.0 of single chip microcontroller 4, P1.1, P1.2, P1.3, P1.4, P1.5, P1.6, P1.7, P2.4, P2.5, P2.6 are connected with DB0, DB1, DB2, DB3, DB4, DB5, DB6, DB7, RS, R/W, the E of display screen 5 respectively; D.C. regulated power supply 6 comprises rectifier bridge heap D, 12V regulator block U3,5V regulator block U4 and electrochemical capacitor C; The anodal V+ of rectifier bridge heap D, the positive pole of electrochemical capacitor C, the input end Vin tandem of 12V regulator block U3; The output terminal of 12V regulator block U3 is connected with the input end Vin of 5V regulator block U4; The output 5V voltage of 5V regulator block U4, the GND end tandem ground connection of the GND end of the negative pole V-of rectifier bridge heap D, the negative pole of electrochemical capacitor C, 12V regulator block U3,5V regulator block U4.

Referring to Fig. 3, the course of work of the present invention is:

1, connect three phase winding A of permagnetic synchronous motor, B, C end with A, B, the C terminal of permagnetic synchronous motor ac-dc axis inductance measurement device of the present invention respectively, connect the 220V power frequency AC, device starts;

2, after the startup; Chip microprocessor R8C/2L at first puts P2.0=1, P2.1=0, P2.2=1, P2.3=0, and K switch A and KB2 are connected, and the industrial-frequency alternating current after the step-down is added between the A phase and B phase winding of permagnetic synchronous motor; This moment, chip microprocessor R8C/2L was with the fixing V signal of time-sampling voltage sensor and the I signal of current sensor of adopting of 0.1ms; Sampling is 10 times in 1ms, according to formula (10), and average computation outlet inductance L AB;

3, behind the 1ms; Chip microprocessor R8C/2L puts P2.0=0, P2.1=1, P2.2=0, P2.3=1, and K switch B1 and KC are connected, and the industrial-frequency alternating current after the step-down is added between the B phase and C phase winding of permagnetic synchronous motor; This moment, chip microprocessor R8C/2L was with the fixing V signal of time-sampling voltage sensor and the I signal of current sensor of adopting of 0.1ms; Sampling is 10 times in 1ms, according to formula (10), and average computation outlet inductance L _BC

4, behind the 1ms; Chip microprocessor R8C/2L puts P2.0=1, P2.1=0, P2.2=0, P2.3=1, and K switch A and KC are connected, and the industrial-frequency alternating current after the step-down is added between the AB phase and C phase winding of permagnetic synchronous motor; This moment, chip microprocessor R8C/2L was with the fixing V signal of time-sampling voltage sensor and the I signal of current sensor of adopting of 0.1ms; Sampling is 10 times in 1ms, according to formula (10), and average computation outlet inductance L _CA

5, behind the 1ms, chip microprocessor R8C/2L puts P2.0=0, P2.1=0, P2.2=0, P2.3=0, calculates d-axis inductance L d respectively and hands over an axle inductance L q according to formula (6) and (7), and result of calculation is delivered to display screen show.

Claims (6)

1. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus; It is characterized in that: comprise insulate step-down transformer (1), isolate sample circuit (2), controlled switch (3), single chip microcontroller (4), LCDs (5), D.C. regulated power supply (6); Power frequency 220V alternating current is connected with controlled switch (3) with isolation sample circuit (2) through insulate step-down transformer (1); The output signal of isolating sample circuit (2) is connected to the analog to digital conversion pin of single chip microcontroller (4); Controlled switch (3) is connected with terminal A, B, C respectively; The control signal of single chip microcontroller (4) is connected with controlled switch (3) control end; The output signal of single chip microcontroller (4) is connected with LCDs (5), and 12V and 5V power supply that D.C. regulated power supply (6) produces are delivered to controlled switch (3) and single chip microcontroller (4) respectively.

2. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus according to claim 1; It is characterized in that: described insulate step-down transformer (1) adopts the unskilled labor frequency power transformer; Comprise primary and secondary; The mutual electrical isolation of primary and secondary elementaryly is electrically connected with the 220V industrial frequency AC, and secondary L, N end are held tandem with two AC of two AC ends of isolating sample circuit (2) voltage sensor U1 and D.C. regulated power supply (6) rectifier bridge heap D respectively.

3. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus according to claim 1; It is characterized in that: described isolation sample circuit (2) comprises voltage sensor U1 and current sensor U2; The V output terminal of U1 is connected with the analog to digital conversion pin P0.1 of single chip microcontroller (4); The I output terminal of U2 is connected with the analog to digital conversion pin P0.2 of single chip microcontroller (4), and the input negative terminal IN-of U2 is connected with the secondary N end of insulate step-down transformer (1), the G end ground connection of U1, U2.

4. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus according to claim 1; It is characterized in that: described controlled switch (3) comprises four relay K A, KB1, KB2, KC and four control triode Q1, Q2, Q3, Q4; Each relay is made up of two switch contacts and a control coil, the L end tandem that the left contact of relay K A, the left contact of KB1 and insulate step-down transformer (1) are secondary, and the right contact of KA is connected with terminal A; The input anode IN+ tandem of the left contact of relay K B2, KC, current sensor U2; Be connected with terminal B after the right contact tandem of KB1, KB2, the right contact of KC is connected with terminal C, and the left end of KA control coil is connected with the collector of triode Q1; The left end of KB1 control coil is connected with the collector of triode Q2; The left end of KB2 control coil is connected with the collector of triode Q3, and the left end of KC control coil is connected with the collector of triode Q4, the right-hand member of KA, KB1, KB2, KC control coil and 12V tandem; The emitting stage of Q1, Q2, Q3, Q4 and ground tandem, Q1, Q2, Q3, Q4 ground level are connected with P2.0, P2.1, P2.2, the P2.3 of single chip microcontroller (4) respectively.

5. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus according to claim 1; It is characterized in that: described single chip microcontroller (4) adopts R8C/2L; Described display screen (5) adopts 1206, and the P1.0 of single chip microcontroller (4), P1.1, P1.2, P1.3, P1.4, P1.5, P1.6, P1.7, P2.4, P2.5, P2.6 are connected with DB0, DB1, DB2, DB3, DB4, DB5, DB6, DB7, RS, R/W, the E of display screen (5) respectively.

6. permagnetic synchronous motor ac-dc axis inductance measurement method and apparatus according to claim 1; It is characterized in that: described D.C. regulated power supply (6) comprises rectifier bridge heap D, 12V regulator block U3,5V regulator block U4 and electrochemical capacitor C; The anodal V+ of rectifier bridge heap D, the positive pole of electrochemical capacitor C, the input end Vin tandem of 12V regulator block U3; The output terminal of 12V regulator block U3 is connected with the input end Vin of 5V regulator block U4; 5V regulator block U4 output 5V voltage, the GND end tandem ground connection of the GND end of the negative pole V-of rectifier bridge heap D, the negative pole of electrochemical capacitor C, 12V regulator block U3,5V regulator block U4.

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