CN104283479B - Permanent magnet synchronous motor load torque monitoring system based on three-dimensional motor parameter tables - Google Patents

Abstract

The invention provides a permanent magnet synchronous motor load torque monitoring system based on three-dimensional motor parameter tables, and relates to the field of motor control. The influences of temperature on motor parameters are omitted in the current motor torque monitoring process, so that a large difference still exists between torque acquired through calculation and the actual value. According to the technical scheme, the system comprises an a-phase current sensor, a b-phase current sensor, a position sensor, a coordinate conversion unit, a temperature sensor, a rotor temperature calculation unit, a three-dimensional motor parameter storage unit and a load torque calculation unit. By the adoption of the technical scheme, the motor temperature sensor is arranged, the accuracy of load torque calculation is improved, the requirement for the calculation capacity of a chip is lowered, cost is reduced, and the response speed is high.

Description

Permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table

Technical field

The present invention relates to the present invention relates to Motor Control Field, especially for a kind of monitoring system of motor.

Background technology

Permagnetic synchronous motor is widely used, it is that motor can be at full speed to the major requirement of motor in electric automobile In the range of and full-load range in provide accurate direct torque.In addition, by contrast car load give command torque with The actual torque of motor system, can indirectly reflect the running status of motor system, infer whether faulty.Comprehensive From the point of view of, the measurement of torque, for electric automobile, is not only to ensure that the requirement of control performance, and even more one important safety is special Levy.

Actual torque can accurately be obtained by torque measurement instrument, but be constrained to the cost control of electric automobile, weight Amount and locus etc. require, and this method is not applied to electric automobile field.Existing torque measurement is mainly passed through , come to realize, its theory diagram is as shown in Figure 1 for load torque observer.The accurate acquisition of the parameter of electric machine is load torque observer The essential condition of accurate surveying.Existing parameter of electric machine acquisition methods are mainly realized by on-line parameter identification, but this Plant acquisition methods on-line parameter identification algorithm is had high demands, increased the complexity of control system.Also partial parameters are had to distinguish online Know the saturated characteristic that algorithm considers permanent magnet, improve the precision of torque observation, but these methods have ignored temperature to electricity Still there is bigger difference so that calculating and obtaining torque with reality in the impact of machine parameter.

Content of the invention

The technical problem to be solved in the present invention and the technical assignment proposing are prior art to be improved and is improved, There is provided the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table, to improve the mesh of torque calculation accuracy 's.For this reason, the present invention takes technical scheme below.

Permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table is it is characterised in that include:

A phase current sensor: for a phase current i_aSampled；

B phase current sensor: for b phase current i_bSampled；

Position sensor: for detecting rotor position；

Coordinate transformation unit: be connected with a phase current sensor and b phase current sensor, for according to a phase current i_a, b phase Electric current i_b, rotor position be calculated motor d shaft current i_dWith q shaft current i_q；

Temperature sensor: for measuring stator temperature t_s；

Temperature of rotor calculates unit: is connected with temperature sensor, for according to stator temperature t_sIt is calculated rotor Temperature t_r；

Three-dimensional parameter of electric machine memory element: for storage corresponding to d shaft current i_d, q shaft current i_qWith motor rotor temperature t_r Motor d axle inductance l_d, q axle inductance l_qWith permanent magnet flux linkage ψ_f；

Load torque computing unit: calculate unit with coordinate transformation unit and temperature of rotor and be connected, for according to d shaft current i_d, q shaft current i_qInquire about three-dimensional parameter of electric machine memory element with motor rotor temperature tr and obtain motor d axle inductance l_d, q axle inductance l_qWith permanent magnet flux linkage ψ_f, and according to motor d axle inductance l_d, q axle inductance l_q, permanent magnet flux linkage ψ_f, d shaft current i_d, q shaft current i_qComputational load torque t_e.

The technical program sets motor temperature sensor, improves the accuracy of computational load torque, and on the other hand, its load turns During square calculates, the used parameter of electric machine is by the running status following motor in real time of tabling look-up, and therefore observes the load obtaining and turns Square has higher precision and faster response speed, and the parameter of electric machine is previously set, and the computing capability reducing chip requires, and reduces Cost.

As improving further and supplementing to technique scheme, present invention additionally comprises following additional technical feature.

Described temperature sensor at least provided with the first temperature sensor, second temperature sensor, described the first temperature Sensor, second temperature sensor are embedded in motor stator side；Temperature of rotor calculates unit according to the first temperature sensor measurement Temperature t_s1, second temperature sensor measurement temperature t_s2And two temperature measuring points calculate with respect to the thermal resistance data of rotor Obtain motor rotor temperature t_r.If multiple temperature sensors are conducive to improving the accuracy of the monitoring of temperature.

In three-dimensional parameter of electric machine memory element, three-dimensional parameter of electric machine manufacture method comprises the following steps:

1) to d shaft current i_d, q shaft current i_qWith temperature of rotor t_rIt is combined, carry out multiple motor finite element simulation and divide Analysis；

2) data of finite element analyses is carried out Data Analysis Services, generate d axle inductance l respectively_dEmulation tables of data, q axle Inductance l_qEmulation tables of data and permanent magnet flux linkage ψ_fEmulation tables of data；

3) arrange emulation tables of data, list data is carried out with continuous treatment, connect continuousization processing mode and include interpolation method Calculate；

4) initial three-dimensional parameter of electric machine table, respectively d axle inductance l are obtained_dThree-dimensional parameter of electric machine table, q axle inductance l_qThree-dimensional Parameter of electric machine table and permanent magnet flux linkage ψ_fThree-dimensional parameter of electric machine table；

5) record actual measurement torque under different running statuses for the motor and observation torque；

6) if observation torque exceedes allowed band with the error of actual measurement torque, need three-dimensional parameter of electric machine table is carried out Error correction, and repeat step 5) operation；

7) when meeting the requirement in allowed band for the error of observation torque and actual measurement torque, the final three-dimensional electricity of output Machine parameter list.

Coordinate transformation unit includes two kinds in the mode carrying out Coordinate Conversion: permanent amplitude transformation and invariable power conversion, permanent width Value transformation calculations are shown in formula (1), and invariable power transformation calculations are shown in formula (2):

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]---\left(1\right)$

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]---\left(2\right)$

Motor rotor temperature t_rComputing formula is:

$t_r=\frac{t_{s2}-t_{s1}}{r_{\mathrm{th}1}}\·r_{\mathrm{th}2}+t_{s2};$

In formula: r_th1And r_th2It is respectively the thermal resistance data that two temperature measuring points are with respect to rotor.

Load torque computing unit computational load torque t_eFormula be: t_e=1.5n_p(l_di_di_q-l_qi_di_q+ψ_fi_q)；Formula Middle n_pFor permagnetic synchronous motor magnetic to number of poles.

Beneficial effect:.

Brief description

Fig. 1 is existing torque precise control closed loop system structured flowchart.

Fig. 2 is present configuration block diagram.

Fig. 3 is the flow chart of the three-dimensional parameter of electric machine table manufacture method of the embodiment of the present invention.

In figure: 1-b phase current sensor, 2- position sensor, 3- coordinate transformation unit, 4- first temperature sensor, 5- Second temperature sensor, 6- temperature of rotor calculates unit, 7- three-dimensional parameter of electric machine table, 8-a phase current sensor, 9- load torque Computing unit.

Specific embodiment

Below in conjunction with Figure of description, technical scheme is described in further detail.

As shown in Fig. 2 the present invention includes a phase current sensor 8, b phase current sensor 1, position sensor 2, coordinate change Change unit 3, load torque computing unit 9, the first temperature sensor 4, second temperature sensor 5, temperature of rotor calculating unit 6 and The three-dimensional parameter of electric machine memory element of the three-dimensional parameter of electric machine table 7 of storage, a phase current sensor 8 and b phase current sensor 1 detect Go out biphase phase current i_aAnd i_b, position sensor 2 detects rotor position, the first temperature sensor 4 and second temperature sensing Device 5 detects motor stator temperature t_s1And t_s2.

i_a、i_bIt is input in coordinate transformation unit 3 with θ and be calculated motor d shaft current i_dWith_qShaft current i_q.Coordinate transform There are two kinds of forms: permanent amplitude transformation and invariable power conversion, permanent amplitude transformation formula is:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]$

Invariable power transformation for mula is:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]$

Temperature sensor 4 and temperature sensor 5 are embedded in two temperature measuring points of motor stator side, its temperature respectively Testing result is expressed as t_s1And t_s2.This two temperature surveys can be obtained by Theoretical Calculation, simulation analysis or experiment measurement Point is expressed as r with respect to the thermal resistance data of rotor_th1And r_th2.By t_s1And t_s2It is input to temperature of rotor and calculate unit 6 Temperature of rotor t can be calculated_rIt may be assumed that

$t_r=\frac{t_{s2}-t_{s1}}{r_{\mathrm{th}1}}\·r_{\mathrm{th}2}+t_{s2}$

i_d、i_qAnd t_rThree signal inputs, to three-dimensional parameter of electric machine table 7, are inquired about respectively and are obtained d axle inductance l_d、_qAxle inductance l_q With permanent magnet flux linkage ψ_f.Again by l_d、l_q、ψ_f、i_dAnd i_qIt is input in load torque computing unit 9 and be calculated load torque t_e, torque calculation formula is:

t_e=1.5n_p(l_di_di_q-l_qi_di_q+ψ_fi_q).

In Fig. 3, in load torque observer using to the manufacture method of three-dimensional parameter of electric machine table 7 comprise the following steps:

1) to d shaft current i_d, q shaft current i_qWith temperature of rotor t_rCarry out reasonable combination, the motor carrying out abundant number of times is limited First simulation analysis.

2) data of finite element analyses is derived, and carry out data processing in a computer, generate d axle inductance l respectively_dImitative True data table, q axle inductance l_qEmulation tables of data and permanent magnet flux linkage ψ_fEmulation tables of data.

3) arrange emulation tables of data, can be more excellent by simple linear interpolation or other between adjacent cells lattice in form Method realizes the continuous treatment of list data.

4) initial three-dimensional parameter of electric machine table, respectively d axle inductance l are obtained_dThree-dimensional parameter of electric machine table, q axle inductance l_qThree-dimensional Parameter of electric machine table and permanent magnet flux linkage ψ_fThree-dimensional parameter of electric machine table.

5) record actual measurement torque under different running statuses for the motor and observation torque.

6) if observation torque exceedes allowed band with the error of actual measurement torque, need three-dimensional parameter of electric machine table is carried out Error correction, and repeat step 5) operation.

7) when meeting the requirement in allowed band for the error of observation torque and actual measurement torque, the final three-dimensional electricity of output Machine parameter list.

Figure 2 above, the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table shown in 3 are these Bright specific embodiment, has embodied substantive distinguishing features of the present invention and progress, can be according to actual use needs, in the present invention Enlightenment under, it is carried out with the equivalent modifications of the aspects such as shape, structure, all in the row of the protection domain of this programme.

Claims (5)

1. the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table is it is characterised in that include

A phase current sensor: for a phase current i_aSampled；

B phase current sensor: for b phase current i_bSampled；

Position sensor: for detecting rotor position；

Coordinate transformation unit: be connected with a phase current sensor and b phase current sensor, for according to a phase current i_a, b phase current i_b, rotor position be calculated motor d shaft current i_dWith q shaft current i_q；

Temperature sensor: for measuring stator temperature t_s；

Temperature of rotor calculates unit: is connected with temperature sensor, for according to stator temperature t_sIt is calculated motor rotor temperature t_r；

Three-dimensional parameter of electric machine memory element: for storage corresponding to d shaft current i_d, q shaft current i_qWith motor rotor temperature t_rElectricity Machine d axle inductance l_d, q axle inductance l_qWith permanent magnet flux linkage ψ_f；

Load torque computing unit: calculate unit with coordinate transformation unit and temperature of rotor and be connected, for according to d shaft current i_d、q Shaft current i_qWith motor rotor temperature t_rThe three-dimensional parameter of electric machine memory element of inquiry obtains motor d axle inductance l_d, q axle inductance l_qWith Permanent magnet flux linkage ψ_f, and according to motor d axle inductance l_d, q axle inductance l_q, permanent magnet flux linkage ψ_f, d shaft current i_d, q shaft current i_qMeter Calculate load torque t_e；

In three-dimensional parameter of electric machine memory element, three-dimensional parameter of electric machine manufacture method comprises the following steps:

1) to d shaft current i_d, q shaft current i_qWith temperature of rotor t_rIt is combined, carry out multiple motor Finite Element Simulation Analysis；

2) data of finite element analyses is carried out Data Analysis Services, generate d axle inductance l respectively_dEmulation tables of data, q axle inductance l_q Emulation tables of data and permanent magnet flux linkage ψ_fEmulation tables of data；

3) arrange emulation tables of data, list data is carried out with continuous treatment, connect continuousization processing mode and include interpolation calculation；

4) initial three-dimensional parameter of electric machine table, respectively d axle inductance l are obtained_dThree-dimensional parameter of electric machine table, q axle inductance l_qThree-dimensional motor Parameter list and permanent magnet flux linkage ψ_fThree-dimensional parameter of electric machine table；

5) record actual measurement torque under different running statuses for the motor and observation torque；

6) if observation torque exceedes allowed band with the error of actual measurement torque, need to carry out error to three-dimensional parameter of electric machine table Revise, and repeat step 5) operation；

7) when meeting requirement in allowed band for the error observing torque and actual measurement torque, the final three-dimensional motor ginseng of output Number table.

2. the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table according to claim 1, its Be characterised by: described temperature sensor at least provided with the first temperature sensor, second temperature sensor, described the first temperature Sensor, second temperature sensor are embedded in motor stator side；Temperature of rotor calculates unit according to the first temperature sensor measurement Temperature t_s1, second temperature sensor measurement temperature t_s2And two temperature measuring points calculate with respect to the thermal resistance data of rotor Obtain motor rotor temperature t_r.

3. the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table according to claim 1, its It is characterised by: coordinate transformation unit includes two kinds in the mode carrying out Coordinate Conversion: permanent amplitude transformation and invariable power conversion, permanent width Value transformation calculations are shown in formula (1), and invariable power transformation calculations are shown in formula (2):

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{cc}cos\mathrm{\θ}& sin\mathrm{\θ}\\ -sin\mathrm{\θ}& cos\mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]---\left(1\right)$

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{3}{2}& 0\\ \frac{\sqrt{3}}{2}& \sqrt{3}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\end{array}\right]---\left(2\right)$

4. the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table according to claim 2, its It is characterised by: motor rotor temperature t_rComputing formula is:

$t_r=\frac{t_{s2}-t_{s1}}{r_{th1}}\·r_{th2}+t_{s2};$

In formula: r_th1And r_th2It is respectively the thermal resistance data that two temperature measuring points are with respect to rotor.

5. the permagnetic synchronous motor load torque monitoring system based on three-dimensional parameter of electric machine table according to claim 1, its It is characterised by: load torque computing unit computational load torque t_eFormula be: t_e=1.5n_p(l_di_di_q-l_qi_di_q+ψ_fi_q)；Formula Middle n_pFor permagnetic synchronous motor magnetic to number of poles.