CN104201961A - Scheme for measuring initial static parameters of three-phase permanent-magnet synchronous motor - Google Patents

Abstract

The invention discloses a scheme for measuring initial static parameters of a three-phase permanent-magnet synchronous motor. The scheme for measuring the initial static parameters of the three-phase permanent-magnet synchronous motor is aimed to measure basic electric parameters of the motor before driving a third-party rare-earth permanent-magnet synchronous motor. The scheme for measuring the initial static parameters of the three-phase permanent-magnet synchronous motor includes that a) after effectively connecting a drive transducer with a measured motor in an electric mode, enabling the measured motor to arrive at a normal working state; b) locating initially, to be specific, locating the rotor angle theta of the motor at -Pi/6 electrical angle, sending rated current of which the voltage vector is 100% of that of the measured motor, and calculating the internal resistance Rs of the motor; c) sending a voltage vector with a certain linear slope at the -Pi/6 electrical angle to enable the current to be continuous and arrive at 200% rated current of the motor, and calculating a direct-axis inductance Ld; d) resetting and outputting the voltage vector, and waiting for the motor current to return to zero; e) locating secondarily, sending the voltage vector, and locating the motor rotor angle theta at +Pi/6 electric angle; f) sending the voltage vector with a certain linear slope at the +Pi/6 electric angle to enable the current to be continuous and arrive at 200% rated current of the motor, and calculating a q-axis inductance Lq; h) resetting and outputting the voltage vector, and waiting for the motor current to return to zero; ending the test.

Description

A kind of scheme of measuring three-phase permanent-magnetic synchronous motors initial static parameter

Technical field:

This invention is a kind of scheme of measurement of initial static parameter of three-phase rare-earth permanent-magnet synchronous motor.

Background technology:

Along with the exploitation of rare earth permanent-magnet synchronization motor and application have expanded the application of permanent magnet synchronous motor at industry-by-industry, the most significant performance characteristics of rare-earth permanent-magnet electric machine is lightness, high performance, energy-efficient.Under the overall situation of environmental protection and energy conservation, the application that is applied in industrial aspect of rare-earth permanent-magnet electric machine has obtained very fast development.

What the driving control device of three-phase rare-earth permanent-magnet synchronous machine mainly adopted in the market is vector control or Direct Torque Control.This type of control method is to be based upon in the Mathematical Modeling of three-phase motor with permanent magnets, therefore need to obtain the internal resistance of motor and the accurate parameter of ac-dc axis inductance, just can accurately control.For the control algolithm without position three-phase permanent magnet synchronous motor, the accurate parameter that needs especially motor is foundation.

Therefore at the three-phase permanent magnet synchronous motor providing for third party, the three-phase permanent magnet synchronous motor of main flow mainly contains face dress formula rotor and inserted type rotor structure at present, and wherein face dress formula stator air gap is even, its inductance parameters Lq=Ld; And for inserted type rotor structure stator non-uniform air-gap, generally its inductance parameters Lq > Ld, causes its corresponding motor data model variant.For the three-phase permanent magnet synchronous motor of different rotor structure, to the requirement of control device, be, can its electric basic parameter of automatic Identification.

Summary of the invention:

This invention main purpose is in the driving of three-phase rare-earth permanent-magnet synchronous machine, to control driver to drag before third party's motor, the measurement to the basic electric parameter of this motor.Carry out this work, only need a motor to drive frequency converter and by measured motor, and relevant cable connection fittings etc.Implementation step comprises:

(a) after being effectively electrically connected to motor driver with by measured motor, giving and drive frequency converter power transmission, make to drive frequency converter can reach normal operating conditions.

(b) initial alignment, given by twice vector voltage, is positioned at angle of rotor of motor θ in electrical degree direction, send the size of voltage vector, the size that makes sample rate current is by 100% rated current of measured motor.Voltage vector direction is for the first time electrical degree, be 5s preset time continuously, voltage vector direction is for the second time electrical degree, be 10s preset time continuously, sampling phase current, the internal resistance Rs of calculating motor.

(c) by existing continuously electrical degree direction sends the voltage vector of certain linear gradient, makes current continuity and reaches motor rated current 200%.Calculate motor d-axis inductance L d.

(d) zero clearing output voltage vector, waits for time delay 5s, waits for that current of electric makes zero.

(f) locate for the second time, send voltage vector, angle of rotor of motor θ is positioned at

(h) by existing continuously electrical degree direction sends the voltage vector of certain linear gradient, makes current continuity and reaches 200% motor rated current.Calculate motor quadrature axis inductance L q.

(i) zero clearing output voltage vector, waits for time delay 5s, waits for that current of electric makes zero.

Accompanying drawing explanation:

Fig. 1 is the control structure schematic diagram of three-phase rare-earth permanent-magnet synchronous machine.

Fig. 2 is the voltage vector schematic diagram that adopts two-phase conduction mode.

Fig. 3 is that three-phase plug-in type rare earth permanent-magnet synchronization motor d-axis inductance L d and quadrature axis inductance L q and motor electrical degree are related to schematic diagram.

Fig. 4 is that the mounted rare earth permanent-magnet synchronization motor d-axis of three-phase meter inductance L d and quadrature axis inductance L q and motor electrical degree are related to schematic diagram.

Fig. 5 carries out permanent magnet synchronous motor parameter detecting process scheme schematic flow sheet.

Embodiment:

The static parameter of permanent magnet synchronous motor mainly comprises motor internal resistance and motor inductance, and as shown in Figure 5, what first measure is the internal resistance of motor to measurement implementation process of the present invention, measures respectively thereafter d-axis inductance L d and the quadrature axis inductance L q of motor.When test third party motor, first motor housing is fixed, prevent when testing, there is rollover or roll in motor, then according to as shown in Figure 1, by frequency converter with treat that measured motor is electrically connected, three phase mains R, S, T are inputed to frequency converter direct current supply.Step S11: for avoiding locating unsuccessfully, location is divided into two steps.The first step: as shown in Figure 1, first VT6 is managed to conducting, VT3 pipe is carried out to PWM modulation, its modulation duty cycle D is according to certain rate of rise output, the voltage vector now sending is Tbc direction shown in Fig. 2, judge whether the size of electric current reaches the load current value of motor simultaneously, as reached, keep output 5s, then make VT3 modulation duty cycle D be output as 0 according to certain descending slope.Second step: as shown in Figure 1, first VT4 is managed to conducting, VT1 pipe is carried out to PWM modulation, its modulation duty cycle D is according to certain rate of rise output, the voltage vector now sending is Tab direction shown in Fig. 2, at this moment motor can navigate to that Tab direction is consistent as shown in Figure 2, and the rotor that is about to motor is positioned at in the direction of electrical degree, judge whether the size of electric current reaches the load current value of motor simultaneously, as reached, keep output 10s, and record the current average Iav1 in maintenance stage.Step S12: after obtaining current average, shown in Fig. 1, when the second location current of 11 steps is stablized, the C of motor mutually not conducting does not have electric current, and in the situation that ignoring motor leakage inductance, now permanent magnet synchronous motor line voltage equation is after current stabilization, second of equation the right is zero, so above formula is reduced to U _ab=Iav1*2Rs, and U _ab=D1*U _dc-2V _ce, finally can draw the computing formula of motor internal resistance Rs:

R _s＝(D1*U _dc-2V _ce)/(2*Iav1)

V wherein _cepressure drop during for compensation IGBT conducting, U _dcfor the d-c bus voltage value of current frequency converter sampling, La, Lb are each phase self-induction of motor, and Mab is its mutual inductance, and D1 is the PWM dutyfactor value under current stable state.

Step S13: complete at step S12 after the maintenance output of 10s, be positioned at current rotor in the direction of electrical degree, continue to increase the size of VT1 pipe PWM duty ratio D, the amount Δ D that the time that the increase strategy of D is now 50us increases is 0.01%, when motor winding changes duty ratio D big or small, can think that it is linear that electric current changes within the time of 50us, when passing through N1*50us after the time, when detection electric current reaches 200% left and right, by sampling, obtain current peak Ipk1 now.By formula known, the duty ratio of establishing under stable state is now D2, and voltage equation equation is expressed as:

$D2*U_{\mathrm{dc}}-{2V}_{\mathrm{ce}}=\mathrm{Ipk}1*(2*\mathrm{Rs})+(\mathrm{La}+\mathrm{Lb}-2\mathrm{Mab})*\frac{\mathrm{Ipk}1}{N1*50}---\left(a\right)$

In the motor mathematical model of three-phase permanent magnet synchronous motor, can derive, as shown in Figure 1, and in the situation that C disconnects mutually, the inductance L between A phase and B phase _abquadrature axis inductance L with motor _qwith d-axis inductance L _drelation as shown in the formula (b).For plug-in permanent magnet synchronous motor, its alternate inductance L _abas shown in Figure 3, its value size is the function of electrical degree θ within the scope of 180 ° of electrical degrees, and for surface-mount type permanent magnet synchronous motor, its alternate inductance L _abas shown in Figure 4, its value size is constant constant, i.e. L within the scope of 180 ° of electrical degrees _ab=2L _d=2L _q.

$L_{\mathrm{ab}}=L_d+L_q+(L_d-L_q)*\cos (2\mathrm{\θ}+\frac{\mathrm{\π}}{3})---\left(b\right)$

Wherein θ is the angle between rotor d axle and stator A phase winding axis.

At this moment, because motor is positioned at band formula enters (b), can obtain L now _ab=2L _d, bring this formula into formula and enter (a), can obtain d-axis inductance L _dcomputing formula be:

$L_d=(D2*U_{\mathrm{dc}}-{2V}_{\mathrm{ce}}-\mathrm{Ipk}1*2*\mathrm{Rs})*\frac{N1*50}{2*\mathrm{Ipk}1}---\left(c\right)$

Step S14: the duty ratio that reduces PWM according to certain descending slope is 0%, then waits for time delay 5s, the electric current of this formula motor all reduces to zero, by (c) formula, calculates motor d-axis inductance parameters L _d.

Step S15: for the second time location, shown in Fig. 1, conducting be A phase and C phase, B is off-state mutually.First VT6 is managed to conducting, VT1 pipe is carried out to PWM modulation, its modulation duty cycle D is according to certain rate of rise output, and the voltage vector now sending is Tac direction shown in Fig. 2, and the rotor that is about to motor is positioned at in the direction of electrical degree, judge whether the size of electric current reaches the load current value of motor simultaneously, as reached, keep output 5s.

Step S16: complete at step S15 after the maintenance output of 5s, be positioned at current rotor in the direction of electrical degree, continue to increase the size of VT1 pipe PWM duty ratio D, the amount Δ D that the time that the increase strategy of D is now 50us increases is 0.01%, when motor winding changes duty ratio D big or small, can think that it is linear that electric current changes within the time of 50us, when passing through N2*50us after the time, when detection electric current reaches 200% left and right, by sampling, obtain current peak Ipk2 now.By formula known, the duty ratio of establishing under stable state is now D3, and voltage equation equation is:

$D3*U_{\mathrm{dc}}-{2V}_{\mathrm{ce}}=\mathrm{Ipk}2*(2*\mathrm{Rs})+(\mathrm{La}+\mathrm{Lc}-2\mathrm{Mac})*\frac{\mathrm{Ipk}2}{N2*50}---\left(d\right)$

In the motor mathematical model of three-phase permanent magnet synchronous motor, can derive, as shown in Figure 1, and in the situation that B disconnects mutually, the inductance L between A phase and C phase _acquadrature axis inductance L with motor _qwith d-axis inductance L _drelation as shown in the formula:

$L_{\mathrm{ac}}=L_d+L_q+(L_d-L_q)*\cos (2\mathrm{\θ}+\frac{\mathrm{\π}}{3})---\left(e\right)$

The angle between θ rotor d axle and stator A phase winding axis wherein.

At this moment, because motor is positioned at band formula enters (e), can obtain now bring this formula into formula and enter (d), can obtain quadrature axis inductance L _qcomputing formula be:

$L_q=1.5*[(D3*U_{\mathrm{dc}}-{2V}_{\mathrm{ce}}-\mathrm{Ipk}2*2*\mathrm{Rs})*\frac{N2*50}{2*\mathrm{Ipk}2}-0.5L_d]---\left(f\right)$

Step S17: the duty ratio that reduces PWM according to certain descending slope is 0%, then waits for time delay 5s, the electric current of this formula motor all reduces to zero, by (f) formula, calculates motor quadrature axis inductance L _q.

The above; be only preferably specific embodiments of the present invention, but protection scope of the present invention is not limited to this, any technical staff who is familiar with permagnetic synchronous motor control is on basis of the present invention; can be changed easily and be replaced, all should be contained within the scope of the invention.

Claims (10)

1. a scheme of measuring three-phase permanent-magnetic synchronous motors initial static parameter, is characterized in that, comprising:

A) with frequency converter, third party's permagnetic synchronous motor is carried out to upper electrical testing, need fixed electrical machinery shell.

B) initial alignment for the first time, is positioned at rotor in electrical degree direction, the size of controlling the duty ratio D of output voltage makes current of electric reach 100% rated current, and calculates the internal resistance Rs value of motor.

C) by adjusting the size of duty ratio D, make current of electric reach 200% rated current, record current dutyfactor value and sample rate current maximum, and calculate motor d-axis inductance L d.

D) zero clearing output voltage vector, waits for time delay 5s, waits for that current of electric makes zero.

E) locate for the second time, send voltage vector, angle of rotor of motor θ is positioned at in electrical degree direction, the size of controlling the duty ratio D of output voltage makes current of electric reach 100% rated current.

F) by adjusting the size of duty ratio D, make current of electric reach 200% rated current, record current dutyfactor value and sample rate current maximum, and calculate motor quadrature axis inductance L q.

G) zero clearing output voltage vector, waits for time delay 5s, waits for that current of electric makes zero.

2. according to claim 1, it is characterized in that: described step b) location adopts 2 locate modes, first send the voltage vector of Tbc direction, then send the voltage vector of Tab direction.

3. it is characterized in that according to claim 1: the amount Δ D that the time that the duty ratio D modulation strategy described step c) adopting is 50us increases is 0.01%.

4. according to claim 1, it is characterized in that: according to claim 1, it is characterized in that: described step c) at angle of rotor of motor θ, be positioned at during electrical degree location Calculation, the tube voltage drop 2Vce in the time of must compensating IGBT conducting.

5. it is characterized in that according to claim 1: described step c) at angle of rotor of motor θ, be positioned at during electrical degree location Calculation, the alternate inductance L ab=2*Ld of measured motor.

6. according to claim 1, it is characterized in that: the duty ratio that described steps d) reduces PWM at the descending slope according to certain is 0%, then waits for time delay 5s, the phase current of judgement sampling motor all reduces to zero.

7. according to claim 1, it is characterized in that: while described step e) locating, send the voltage vector of Tac direction.

8. it is characterized in that according to claim 1: the amount Δ D that the time that the duty ratio D modulation strategy described step f) adopting is 50us increases is 0.01%.

9. according to claim 1, it is characterized in that: according to claim 1, it is characterized in that: described step f) at angle of rotor of motor θ, be positioned at during electrical degree location Calculation, the tube voltage drop 2Vce in the time of must compensating IGBT conducting.

10. it is characterized in that according to claim 1: described step f) at angle of rotor of motor θ, be positioned at during electrical degree location Calculation, the alternate inductance L ac=1.5*Lq+0.5Ld of measured motor.