CN1420620A - Device and method for testing rotor position of permasyn motor - Google Patents

Abstract

A detecting device of rotor position for synchronous motor of permanent magnet type includes the driving part of the motor and control part whose output end is connected with the input end of motor's driving part. The detecting method for it comprises as the follows: to detect the three phase voltage and the corresponding three phase current stage loaded on the synchronous motor, to calculate out the voltage of two phase and to separate the voltage source of each calculated voltage based on the overlapping principle, to set up the current equation for the stator of the motor, to set up the difference of synchronous current of permanent magnet type, to set up the current equation for the rotor of the motor to derive out the position information of the rotor, the output specified signal to let the motor to carry on driving based on the rotor current equation.

Description

The detecting apparatus for rotor position of permanent-magnet synchronous electric motor and method

One, technical field

The present invention relates to permanent-magnet synchronous electric motor (Permanent Magnet Synchronouselectric Motor), particularly relate to the detecting apparatus for rotor position and the detection method of permanent-magnet synchronous electric motor.

Two, background technology

Traditional permanent-magnet synchronous electric motor detecting apparatus for rotor position as shown in Figure 1, it comprises following components: the output three-phase voltage (Va that drives permanent-magnet synchronous electric motor (20) usefulness, Vb, Vc) rotor-position signal that motor driven portion (10), the test section (30) that detects the rotor-position of above-mentioned permanent-magnet synchronous electric motor (20), the above-mentioned test section of foundation (30) detect, the output control signal is to drive the microprocessor (40) of permanent-magnet synchronous electric motor work.

Adopt the operation principle of detecting apparatus for rotor position of above-mentioned traditional permanent-magnet synchronous electric motor as described below:

As shown in Figure 1, motor driven portion (10) is according to the control signal of microprocessor (40), and (Va, Vb Vc), drive permanent-magnet synchronous electric motor (20) work to the output three-phase voltage.

Permanent magnet is equipped with in the inside of permanent-magnet synchronous electric motor, makes mutually excitatory (omitting among the figure) and rotor-position excitatory synchronously.

As a result, above-mentioned mutually excitatoryly carry out excitatoryly exactly, will the rotor-position of bodies and corresponding permanent magnet type synchronous motor be detected in order to make.

At this moment, test section (30) is according to the driving of above-mentioned permanent-magnet synchronous electric motor (20), and the rotor-position of bodies and corresponding permanent magnet type synchronous motor (PMSM) is detected.

Then, above-mentioned microcomputer (40) is received the rotor-position signal that above-mentioned test section (30) detects, and according to the rotor-position signal of importing, controls above-mentioned motor driven portion (10), and above-mentioned permanent-magnet synchronous electric motor (20) is activated.

But, adopt the detecting apparatus for rotor position of above-mentioned traditional permanent-magnet synchronous electric motor to exist following problem.

1, for detecting the rotor-position of permanent-magnet synchronous electric motor, need install a checkout gear (for example: hole sensor, encoder, decomposer etc.) in addition, therefore the corresponding producing cost that increases motor has reduced product yield.

2, according to environment for use, if the checkout gear of sensitive action is housed on permanent-magnet synchronous electric motor, the range of application that will dwindle the motor product perhaps reduces product quality.

3, because permanent-magnet synchronous electric motor is installed checkout gear, thereby, unnecessary placement space will be left in the product, and in other products that use motor, identical motor can not be used.

Three, summary of the invention

In view of the existing the problems referred to above of located by prior art, the objective of the invention is to, a kind of detecting apparatus for rotor position and method of permanent-magnet synchronous electric motor is provided.This checkout gear and method do not need to install in addition an adjunct circuit, just can detect the rotor-position of permanent-magnet synchronous electric motor.

The technical scheme that detecting apparatus for rotor position adopted of permanent-magnet synchronous electric motor of the present invention is:

A kind of detecting apparatus for rotor position of permanent-magnet synchronous electric motor, the invention is characterized in that it comprises motor-driven part and control section, the output of this control section is connected with the input of motor-driven part, this motor driven part is according to the desired signal of input, output is for driving the three phase mains (Va that permanent-magnet synchronous electric motor is used, Vb, Vc); The three-phase voltage that described control section is partly exported described motor driven (Va, Vb is Vc) with corresponding with it three-phase current (ia, ib ic) detects, and the respective three-phase voltage (va to detect, Vb, Vc) and electric current (ia, ib, ic) be benchmark, carry out the calculation process process, detect the rotor position information of permanent-magnet synchronous electric motor, and according to the rotor position information that detects, to described motor portion output control signal, to drive above-mentioned permanent-magnet synchronous electric motor.

The method of the detecting apparatus for rotor position of permanent-magnet synchronous electric motor of the present invention is:

A kind of method of detecting apparatus for rotor position of permanent-magnet synchronous electric motor, it is characterized in that it comprises the following steps: being added in three-phase voltage on the above-mentioned permanent-magnet synchronous electric motor (Va, Vb, Vc) and with it corresponding three-phase current (ia, ib ic) detects; Three-phase voltage to above-mentioned detection carries out calculation process, obtains two-phase voltage (V _α, V _β), and based on principle of stacking, the voltage source of every phase voltage of obtaining is separated, set up the stator current (I of above-mentioned permanent-magnet synchronous electric motor _α ^s, I _β ^s) equation; Three-phase current to above-mentioned detection carries out calculation process, obtains two-phase current (i _α, i _β), and poor according to two-phase current of obtaining and stator current equation set up the rotor current (I of permanent-magnet synchronous electric motor _α ^r, I _β ^r) equation; Based on above-mentioned rotor current equation, calculate the back electromotive force (e of above-mentioned permanent-magnet synchronous electric motor _α, e _β), obtain the positional information (θ e) of above-mentioned rotor, and, export desired signal according to the rotor position information of obtaining, drive this permanent-magnet synchronous electric motor.

The detecting apparatus for rotor position of permanent-magnet synchronous electric motor of the present invention and method have following effect.

1, do not need to install in addition the rotor arrangement that a circuit detects permanent-magnet synchronous electric motor, therefore, saved the producing cost of product, improved the output of product simultaneously.

2, the environment for use with permanent-magnet synchronous electric motor has nothing to do, and can detect the rotor-position of motor accurately, drive motor, thereby the quality of raising product.

3, adopt easy method for detecting position, the rotor-position that is contained in the permanent-magnet synchronous electric motor on the various products is detected, therefore, can enlarge the scope of application of product.

Four, description of drawings

Fig. 1 is the frame assumption diagram of the detecting apparatus for rotor position of traditional permanent-magnet synchronous electric motor.

Fig. 2 is the frame assumption diagram of the detecting apparatus for rotor position of permanent-magnet synchronous electric motor of the present invention.

Fig. 3 is the flow chart of the rotor position detecting method of permanent-magnet synchronous electric motor of the present invention.

Fig. 4 is the equivalent circuit diagram of permanent-magnet synchronous electric motor of the present invention.

Fig. 5 a and Fig. 5 b are the equivalent circuit diagram of the permanent-magnet synchronous electric motor shown in Fig. 4.

Fig. 6 a and the schematic diagram of Fig. 6 b in the equivalent electric circuit shown in Fig. 5 a voltage source being separated.

Fig. 7 a and the schematic diagram of Fig. 7 b in the equivalent electric circuit shown in Fig. 5 b voltage source being separated.

Label among Fig. 1

1: motor driven portion, 2: motor, 3: test section, 4: microcomputer

Label among Fig. 2

5: control part, 6: motor driven portion, 7: motor

Label among Fig. 3

1: beginning

2: detect the three-phase voltage be added on the permanent-magnet synchronous electric motor (PMSM) (Va, Vb, Vc) and correspondingly three-phase current (Ia, Ib, Ic) (S100)

3: the three-phase voltage that detects is carried out coordinate transform, calculate the two-phase voltage (V α, V β) of alpha-beta axle.(S110)

4:,, set up the stator current equation of PMSM to the two-phase voltage calculation process of obtaining based on the principle of stack.(S120)

5: the three-phase current that detects is carried out coordinate transform, calculate the two-phase current (i α, i β) of alpha-beta axle.(S130)

6: poor according to two-phase current of obtaining and stator current equation, set up the rotor current equation of PMSM.(S140)

7:, calculate back electromotive force (e α, e β) based on the rotor current equation of setting up.(S150)

8: the back electromotive force of obtaining is carried out calculation process, obtain the rotor position information of PMSM.(S160)

9; According to the rotor-position information that draws, the output desired signal drives PMSM.(S170)

10; Finish.

Five, embodiment

The detecting apparatus for rotor position that adopts permanent-magnet synchronous electric motor of the present invention as shown in Figure 2, the detecting apparatus for rotor position of this permanent-magnet synchronous electric motor comprises motor driven part (100) and control section (300).Motor driven part (100) is along with the input of prearranged signals, output drive above-mentioned permanent-magnet synchronous electric motor (200) usefulness three-phase voltage (Va, Vb, vc); Three-phase voltage (the Va that control section (300) is then exported above-mentioned motor driven part (100), Vb, vc) and corresponding three-phase current (ia, ib, ic) detect, and corresponding three-phase voltage (Va to detect, Vb, Vc) and electric current (ia, ib, ic) be the basis, carry out calculation process, obtain the rotor position information of above-mentioned permanent-magnet synchronous electric motor (200), according to the rotor position information of obtaining, to motor driven part (100), output drives the control signal of above-mentioned permanent-magnet synchronous electric motor (200) usefulness.Consult Fig. 3, the detecting apparatus for rotor position method flow of the permanent-magnet synchronous electric motor of the present invention that adopts said structure be described below:

At first, control section (300) to be added in three-phase voltage on the permanent-magnet synchronous electric motor (200) (Va, Vb, Vc) and corresponding with it three-phase current (ia, ib ic) detect (S100).Here, if based on permanent-magnet synchronous electric motor shown in Figure 4 (200) equivalent electric circuit, (Va, Vb Vc), so, can following routine mathematical expression 1 define to calculate the three-phase voltage of above-mentioned detection.

[mathematical expression 1] $\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\\ \mathrm{Vc}\end{array}\right]=\left[\begin{array}{ccc}\mathrm{Ra}& 0& 0\\ 0& \mathrm{Rb}& 0\\ 0& 0& \mathrm{Rc}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]+\frac{d}{\mathrm{dt}}\left(\left[\begin{array}{ccc}\mathrm{Laa}& \mathrm{Mab}& \mathrm{Mac}\\ \mathrm{Mba}& \mathrm{Lbb}& \mathrm{Mbc}\\ \mathrm{Mca}& \mathrm{Mcb}& \mathrm{Lcc}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]\right)+\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right]$

Va herein, Vb, Vc is for being added in three-phase (a, b, c) voltage on the above-mentioned permanent-magnet synchronous electric motor (200).Ia, ib, ic are and the corresponding electric current of above-mentioned three-phase voltage.

And Ra, Rb, Rc represent the resistance of above-mentioned each coil of three-phase as shown in Figure 4.Ea, eb, ec then represent each three-phase (a, b, c) induced electromotive force on the coil.Laa, Lbb, Lcc have represented the magnetic flux density on each three-phase coil.

And Mab, Mac, Mba, Mbc, Mca, Mcb have represented the mutual inductance value between the coil of each three-phase coil.

Above-mentioned each magnetic strength value (Laa, Lbb, Lcc〉can represent with leakage inductance (1) and each mutual inductance (M) sum of permanent-magnet synchronous electric motor.

For example: magnetic strength Laa is 1+ (Mba+Mac).(Mab+Mac) is (M/2+M/2) accordingly, and therefore, Laa can represent with (1+M).

In a word, each goes up added voltage mutually above-mentioned permanent-magnet synchronous electric motor (200), promptly three-phase voltage (Va, Vb Vc) as defined in the mathematical expression 1, can pass through electric current, speed electromotive force, the correlation of resistance magnetic induction and mutual inductance is calculated.

Here, the stator field line of induction of three-phase axle magnetic field permanent magnet formula synchronous motor shown in Figure 4 can replace with the same line of magnetic induction of mutual 120 ° of electric angles and Ra.

And when the round rotor characteristic of expression permanent-magnet synchronous electric motor, (Laa, Lbb Lcc) depend on the combination of leakage flux chain number to the magnetic strength of each stator phase line of magnetic induction.Magnetic flux chain number has stator phase equally.Above-mentioned mutual inductance value (Mab, Mac, Mba, Mbc, Mca is Mcb) independent with rotor-position.

Then, (Va, Vb Vc) are calculated by the content of following mathematical expression 2 definition the three-phase voltage of mathematical expression 1 definition.

[mathematical expression 2] $\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\\ \mathrm{Vc}\end{array}\right]=\left[\begin{array}{ccc}\mathrm{Ra}+\mathrm{pL}& 0& 0\\ 0& \mathrm{Ra}+\mathrm{pL}& 0\\ 0& 0& \mathrm{Ra}+\mathrm{pL}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]+\left[\begin{array}{c}{e}_a\\ e_b\\ e_c\end{array}\right]$

In the formula: P represents the differential operator of d/dt used in the mathematical expression 1.L then represents 1+3/2M.

Then, the three-phase voltage equation to mathematical expression 2 definition carries out changes in coordinates, the two-phase voltage (V on the calculating α β axle _α, V _β) (S110).

Here above-mentioned three-phase voltage is carried out the two-phase voltage (V that changes in coordinates is obtained _α, V _β), following row mathematical expression 3 defines.

[mathematical expression 3] $\left[\begin{array}{c}{V}_{\mathrm{\α}}\\ V_{\mathrm{\β}}\end{array}\right]=\left[\begin{array}{cc}-\mathrm{Ra}+\mathrm{pL}& 0\\ 0& -\mathrm{Ra}+\mathrm{pL}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right]+\frac{1}{L}\left[\begin{array}{c}{e}_{\mathrm{\α}}\\ e_{\mathrm{\β}}\end{array}\right]$

At this moment, e _α, e _βBe back electromotive force, and above-mentioned three-phase voltage (Va, Vb, Vc).Two-phase voltage (V _α, V _β) and above-mentioned three-phase current (ia, ib, ic).Two-phase current (i _α, i _β), have following mathematical expression 4 defined relations.

[mathematical expression 4] $V_{\mathrm{\α}}=\sqrt{\frac{2}{3}}(\mathrm{Va}-\frac{\mathrm{Vb}}{2}-\frac{\mathrm{Vc}}{2})$ $V_{\mathrm{\β}}=\frac{\mathrm{Vb}-\mathrm{Vc}}{\sqrt{2}}$ $i_{\mathrm{\α}}=\sqrt{\frac{2}{3}}(i_a-\frac{i_b}{2}-\frac{i_c}{2})$ $i_{\mathrm{\β}}=\frac{i_b-i_c}{\sqrt{2}}$

Mathematical expression 3 defined two-phase voltage (V _α, V _β) based on the stack principle, each phase voltage source is separated, set up the stator current equation (I of above-mentioned permanent-magnet synchronous electric motor (200) _α ^s, I _β ^s) (S120).

At this moment, based on the stack principle, to the above-mentioned two-phase voltage (V that asks _α, V _β) carry out the process of calculation process, if be illustrated with reference to Fig. 5 a and Fig. 5 b and Fig. 6 a and Fig. 6 b and Fig. 7 a and Fig. 7 b, so, the above-mentioned two-phase voltage (V that obtains _α, V _β) the same with Fig. 5 b as Fig. 5 a, be expressed as an equivalent electric circuit.

Then, with the V shown in Fig. 5 a _αAnd e _αEquivalent electric circuit for voltage source utilizes principle of stacking, to above-mentioned two voltage source (V _α, e _α) separate, then shown in Fig. 6 a and Fig. 6 b.

At this moment, with above-mentioned V _αBe the equivalent electric circuit of voltage source, the stator current (I of the α axle permanent-magnet synchronous electric motor shown in Fig. 6 a _α ^s) composition, and with above-mentioned e _αFor the equivalent electric circuit of voltage source shown in Fig. 6 b, and with above-mentioned be the equivalent electric circuit of voltage source shown in Fig. 6 b, the rotor current (I of expression α axle permanent-magnet synchronous electric motor _α ^s) composition.

Here, if, set up each voltage source (V based on the equivalent electric circuit shown in Fig. 6 a Fig. 6 b _α, e _α) equation, so, define as shown in the formula mathematical expression 5.

(mathematical expression 5) $V_{\mathrm{\α}}=\mathrm{Ra}\×i_{\mathrm{\α}}^s+L\frac{d}{\mathrm{dt}}{i}_{\mathrm{\α}}^s$ $e_{\mathrm{\α}}=\mathrm{Ra}\×i_{\mathrm{\α}}^r+L\frac{d}{\mathrm{dt}}{i}_{\mathrm{\α}}^r$

Then, with I _α ^sBe standard, to the e of mathematical expression and definition _αPut in order, then, with I _α ^rBe standard, to I _α ^rPut in order, then set up as following mathematical expression 6.

(mathematical expression 6) $\frac{d}{\mathrm{dt}}{i}_{\mathrm{\α}}^s=-\frac{\mathrm{Ra}}{L}{i}_{\mathrm{\α}}^s+\frac{1}{L}\mathrm{V\α}$ $\frac{d}{\mathrm{dt}}{i}_{\mathrm{\α}}^r=-\frac{\mathrm{Ra}}{L}{i}_{\mathrm{\α}}^r+\frac{1}{L}{e}_{\mathrm{\α}}$

Simultaneously, if use principle of stacking, use (the V shown in Fig. 5 b _α, e _α) be in the equivalent electric circuit of voltage source, and to above-mentioned two voltage source (V _α, e _α) separate, then shown in Fig. 7 a and 7b.

At this moment, shown in Fig. 7 a, with above-mentioned V _βMake the equivalent electric circuit of voltage source, the stator current ((I of permanent-magnet synchronous electric motor on the β axle occurs _β ^s) composition, with above-mentioned e _βRotor current (the I of permanent-magnet synchronous electric motor on the β axle shown in Fig. 7 b appears in the equivalent electric circuit of making voltage source _β ^s) composition.

Here, if based on the equivalent electric circuit shown in Fig. 7 a and Fig. 7 b, foundation meets each voltage source (V _βAnd e _β) equation, then following row mathematical expression 7 defines.

(mathematical expression 7) $V_{\mathrm{\β}}=\mathrm{Ra}\×i_{\mathrm{\β}}^s+L\frac{d}{\mathrm{dt}}{i}_{\mathrm{\β}}^s$ $e_{\mathrm{\β}}=\mathrm{Ra}{\×i}_{\mathrm{\β}}^r+L\frac{d}{\mathrm{dt}}{i}_{\mathrm{\β}}^r$

With I _β ^sBe benchmark, to the V of mathematical expression 7 definition _βPut in order, then, with I _β ^rFor benchmark to e _βPut in order, then following row mathematical expression 8 defines.

(mathematical expression 8) $\frac{d}{\mathrm{dt}}{i}_{\mathrm{\β}}^s=-\frac{\mathrm{Ra}}{L}{i}_{\mathrm{\β}}^s+\frac{1}{L}{V}_{\mathrm{\β}}$ $\frac{d}{\mathrm{dt}}{i}_{\mathrm{\β}}^r=-\frac{\mathrm{Ra}}{L}{i}_{\mathrm{\β}}^r+\frac{1}{L}{e}_{\mathrm{\β}}$

At this moment, if by mathematical expression 6 and 8, to the stator current (I of the permanent-magnet synchronous electric motor on the alpha-beta axle _α ^s, I _β ^s) and rotor current (I _α ^r, I _β ^r) put then following row mathematical expression 9 and 10 definition in order.

(mathematical expression 9) $\left[\begin{array}{cc}\frac{d}{\mathrm{dt}}& i_{\mathrm{\α}}^s\\ \frac{d}{\mathrm{dt}}& i_{\mathrm{\β}}^s\end{array}\right]=\left[\begin{array}{cc}-\frac{\mathrm{Ra}}{L}& 0\\ 0& -\frac{\mathrm{Ra}}{L}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}^s\\ i_{\mathrm{\β}}^s\end{array}\right]+\frac{1}{L}\left[\begin{array}{c}{V}_{\mathrm{\α}}\\ V_{\mathrm{\β}}\end{array}\right]$

Here, the stator current (I of permanent-magnet synchronous electric motor _α ^s, I _β ^s) as mathematical expression 9 definition, with two-phase voltage (V _α, V _β) represent.

[mathematical expression 10] $\left[\begin{array}{cc}\frac{d}{\mathrm{dt}}& i_{\mathrm{\α}}^r\\ \frac{d}{\mathrm{dt}}& i_{\mathrm{\β}}^r\end{array}\right]=\left[\begin{array}{cc}-\frac{\mathrm{Ra}}{L}& 0\\ 0& -\frac{\mathrm{Ra}}{L}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}^r\\ i_{\mathrm{\β}}^r\end{array}\right]+\frac{1}{L}\left[\begin{array}{c}{e}_{\mathrm{\α}}\\ e_{\mathrm{\β}}\end{array}\right]$

And, the rotor current (I of permanent-magnet synchronous electric motor _α ^r, I _β ^r) also as mathematical expression 10 is defined, can back electromotive force (e _α, e _β) represent.

Then, if to the stator current (I of the permanent-magnet synchronous electric motor of mathematical expression 9 definition _α ^s, I _β ^s) differential value carries out computing arrangement, the definition of then following row mathematical expression 11 like that, set up stator current equation (I _α ^s, I _β ^s).

[mathematical expression 11] $i_{\mathrm{\α}}^s=\frac{V_{\mathrm{\α}}}{R}(1-e^{-\frac{R}{L}t})+i\left(O\right)e^{-\frac{R}{L}t}$ $i_{\mathrm{\β}}^s=\frac{V_{\mathrm{\β}}}{R}(1-e^{-\frac{R}{L}t})+i\left(O\right)e^{-\frac{R}{L}t}$

Above-mentioned control section (300) is gone up added three-phase voltage to above-mentioned permanent-magnet synchronous electric motor (200), and (Va, Vb Vc) detect, and can know the respective three-phase magnitude of voltage.Simultaneously, according to the definition of mathematical expression 4, also can know above-mentioned two-phase voltage (V _α, V _β) value.

As a result, the variable resistance (R) of permanent-magnet synchronous electric motor and inductance value also are values as can be known, so, according to the definition of mathematical expression 11, just can calculate the stator current (I of permanent-magnet synchronous electric motor _α ^s, I _β ^s).

Then, (ia, ib ic) by the definition of mathematical expression 4, calculate two-phase current (I to above-mentioned detected three-phase current _α, I _β) two-phase current (I of S (140) and aforementioned calculation _α, I _β) and stator current (I _α ^s, I _β ^s) the rotor current equation (I of the corresponding permanent-magnet synchronous electric motor of difference _α ^r, I _β ^r), can set up (S140).

Be that (ia, ib ic) are given value to above-mentioned three-phase current.According to the definition of mathematical expression 4, above-mentioned two-phase rotor current equation (I _α, I _β) through calculation process, following row mathematical expression 12 is defined like that.

[mathematical expression 12] $i_{\mathrm{\α}}^r=\frac{e_{\mathrm{\α}}}{R}(1-e^{-\frac{R}{L}t})+i\left(O\right)e^{-\frac{R}{L}t}$ $i_{\mathrm{\β}}^r=\frac{e_{\mathrm{\β}}}{R}(1-e^{-\frac{R}{L}t})+i\left(O\right)e^{-\frac{R}{L}t}$

Simultaneously, the above-mentioned electric current (I of definition in the mathematical expression 12 _α ^r, I _β ^r) can as mathematical expression 13, define.

[mathematical expression 13] $i_{\mathrm{\β}}^r\left(n\right)=\frac{e_{\mathrm{\β}}\left(n\right)}{R}(1-e^{-\frac{R}{L}\left(\mathrm{\ΔT}\right)})+i_{\mathrm{\β}}^r(n-1)e^{-\frac{R}{L}\left(\mathrm{\ΔT}\right)}$

Then, (formula) of mathematical expression 13 definition is referred to as Kt, to above-mentioned back electromotive force (e _α(n), e _β(n)) arrangement mathematical expression 13, the definition of then following row mathematical expression 14 like that, calculate above-mentioned reaction gesture.

[mathematical expression 14] $e_{\mathrm{\α}}\left(n\right)=\frac{R}{1-K_T}[i_{\mathrm{\α}}^r\left(n\right)-K_T{i}_{\mathrm{\α}}^r(n-1)]$ $e_{\mathrm{\β}}\left(n\right)=\frac{R}{1-K_T}[i_{\mathrm{\β}}^r\left(n\right)-K_T{i}_{\mathrm{\β}}^r(n-1)]$

As the definition of mathematical expression 14,, calculate the rotor position information (θ e) of permanent-magnet synchronous electric motor to the back electromotive force obtained calculation process in addition.(S160)

At this moment, above-mentioned back electromotive force (e _α, e _β) with the positional information (θ e) of above-mentioned rotor, have the relation of definition shown in the following mathematical expression 15.

[mathematical expression 15] $e_{\mathrm{\α}}=-\sqrt{\frac{3}{2}}{\mathrm{\ω}}_e{\mathrm{\λ}}_m\sin \left({\mathrm{\θ}}_e\right)$ $e_{\mathrm{\β}}=\sqrt{\frac{3}{2}}{\mathrm{\ω}}_e{\mathrm{\λ}}_m\cos \left({\mathrm{\θ}}_e\right)$

If to above-mentioned back electromotive force (e _α, e _β) calculation process separately, so, following row mathematical expression 16 is defined like that, can calculate rotor position information (θ e).

[mathematical expression 16] ${\mathrm{\θ}}_e={\tan }^{-1}\left(\frac{e_{\mathrm{\α}}}{e_{\mathrm{\β}}}\right)$

At this moment, above-mentioned back electromotive force (e _α, e _β) value is owing to calculate with mathematical expression 14, so can also obtain mathematical expression 16 defined rotor position informations (θ e).

Then, above-mentioned control section (300) to motor driven part (100) output control signal, drives above-mentioned permanent-magnet synchronous electric motor (200) according to the rotor-position information (θ e) of calculating.(S170)

And above-mentioned motor driven part (100) is according to the control signal of above-mentioned control sections (300), export the three-phase voltage that above-mentioned permanent-magnet synchronous electric motor (200) drives usefulness (Va, Vb, Vc).

Claims (2)

1, a kind of detecting apparatus for rotor position of permanent-magnet synchronous electric motor, the invention is characterized in that it comprises motor-driven part and control section, the output of this control section is connected with the input of motor-driven part, this motor driven part is according to the desired signal of input, output is for driving the three phase mains (Va that permanent-magnet synchronous electric motor is used, Vb, Vc); The three-phase voltage that described control section is partly exported described motor driven (Va, Vb is Vc) with corresponding with it three-phase current (ia, ib ic) detects, and the respective three-phase voltage (va to detect, Vb, Vc) and electric current (ia, ib, ic) be benchmark, carry out the calculation process process, detect the rotor position information of permanent-magnet synchronous electric motor, and according to the rotor position information that detects, to described motor portion output control signal, to drive above-mentioned permanent-magnet synchronous electric motor.

2, a kind of method of detecting apparatus for rotor position of permanent-magnet synchronous electric motor is characterized in that it comprises the following steps:

(Vc) and with it (ia, ib ic) detect corresponding three-phase current for Va, Vb to being added in three-phase voltage on the above-mentioned permanent-magnet synchronous electric motor;

Three-phase voltage to above-mentioned detection carries out calculation process, obtains two-phase voltage (V _α, V _β), and based on principle of stacking, the voltage source of every phase voltage of obtaining is separated, set up the stator current (I of above-mentioned permanent-magnet synchronous electric motor _α ^s, I _β ^s) equation;

Three-phase current to above-mentioned detection carries out calculation process, obtains two-phase current (i _α, i _β), and poor according to two-phase current of obtaining and stator current equation set up the rotor current (I of permanent-magnet synchronous electric motor _α ^r, I _β ^r) equation;

Based on above-mentioned rotor current equation, calculate the back electromotive force (e of above-mentioned permanent-magnet synchronous electric motor _α, e _β), obtain the positional information (θ e) of above-mentioned rotor, and, export desired signal according to the rotor position information of obtaining, drive this permanent-magnet synchronous electric motor.

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