CN104022711B - A kind of surface-mount type permagnetic synchronous motor initial position detection method - Google Patents

Abstract

The invention discloses a kind of surface-mount type permagnetic synchronous motor initial position detection method, the method is on the basis of utilizing pulsating high frequency current injection to realize first initial position estimation, one Injection Signal cycle is evenly divided into four intervals, right in interval I and IIIdThe response of axle high frequency voltage is integrated, or right in interval II and IVdThe response of axle high frequency voltage is integrated, according to the symbol decision of this integrated valuedAxle positive direction, the method judges without the extra positive negative pulse stuffing signal that injectsdAxle positive direction, shortens the estimation time, simplifies estimation procedure.

Description

A method for detecting the initial position of a surface-mounted permanent magnet synchronous motor

technical field

The invention relates to the field of motor control, in particular to a method for detecting the initial position of a surface-mounted permanent magnet synchronous motor.

Background technique

At present, for the initial position detection method of the surface-mounted permanent magnet synchronous motor rotor, the common di/dt type and signal injection type are the main methods.

Yuzawa T, Tanaka K, Moriyama R, et al.An efficient estimation method of sensorless initial rotor position for surface PM synchronous motor[C]//Electric Machines and Drives Conference,2001.IEMDC2001.IEEEInternational.IEEE,2001:44-49. The di/dt is used to detect the rotor position, and the initial position of the rotor is quickly estimated by the half-search method, but the rotor of the motor needs to be fixed during the identification process, and the identification result is affected by the cogging effect. Liu Ying, Zhou Bo, Li Shuai, et al. Rotor initial position detection of surface-mounted permanent magnet synchronous motor with rotor magnet[J]. Proceedings of the Chinese Society for Electrical Engineering, 2011, 31(18): 48-54. Based on the SPMSM stator core Linear saturation characteristics, first inject a high-frequency sinusoidal voltage signal into the d-axis of the estimated rotor synchronous rotation coordinate system, obtain the initial estimated value of the rotor position through closed-loop adjustment, and then inject positive and negative voltage pulses in the direction of the estimated d-axis, using positive and negative currents The positive direction of the d-axis is judged by the difference of the equivalent time constant of the direct axis under the action. This type of method needs to inject signals twice in the whole process of initial position estimation. The process of judging the positive direction of the magnetic pole needs to inject positive and negative voltage pulses and then compare the time it takes for the current response to decay to 0. This process will inevitably take a certain amount of time. Liu Ying, Zhou Bo, Zhao Chengliang, et al. Low-speed position sensorless control of SPMSM based on pulse-vibration high-frequency current injection[J]. Chinese Journal of Electrotechnical Society, 2012, 7(27):139-145. The first use of pulse-vibration high-frequency current injection The SPMSM rotor position estimation method is realized, but there is no mention of how to judge the positive direction of the d-axis.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for detecting the initial position of a surface-mounted permanent magnet synchronous motor in view of the defects of the background technology. The whole process only needs to inject a signal once, which greatly simplifies the initial position detection process.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

A method for detecting the initial position of a surface-mounted permanent magnet synchronous motor, comprising the following steps:

Step A), obtaining the initial estimated value of the rotor position;

Step B), judging the positive direction of the d-axis, and obtaining the compensation value after judging the positive direction of the d-axis;

In step C), the initial estimated value of the rotor position is added to the compensation value after judging the positive direction of the d-axis to obtain the final estimated value of the initial position.

As a further optimization scheme of the initial position detection method of a surface-mounted permanent magnet synchronous motor in the present invention, the steps for obtaining the initial estimated value of the rotor position are as follows:

Step A.1), the q-axis current of the estimated rotor synchronous rotation coordinate system is given as 0, and the d-axis current is given as a pulse vibration high-frequency sinusoidal signal I _mh sin(ω _h t), where I _mh is at The amplitude of the high-frequency current injected on the d-axis, ω _h is the angular frequency of the high-frequency current injected on the d-axis, and t represents the current moment;

Step A.2), using a proportional resonant controller to control the estimated d-axis current and q-axis current to make them consistent with the given;

Step A.3), comparing the output voltage of the proportional resonant controller and Perform Park inverse transformation to obtain the voltages u _α and u _β in the two-phase static α-β coordinate system, and then use the space vector pulse width modulation strategy to obtain the six-way switching signals of the three-phase inverter to drive the surface-mounted permanent magnet synchronous motor ;

Step A.4), detect any two-phase current in the three-phase winding A/B/C of the motor, first perform Clarke transformation to obtain the current i _α and i _β in the two-phase static α-β coordinate system, and then obtain Estimating the d-axis current in the rotor synchronously rotating coordinate system and q-axis current Feed it back to the proportional resonant controller;

Step A.5), will estimate the q-axis voltage response of the rotor synchronously rotating coordinate system The AC component with a frequency of ω _h is selected through a band-pass filter, which is the first harmonic component of the q-axis voltage response Then multiplied with the cosine signal cos(ω _h t) for modulation to obtain a DC component and an AC component with a frequency of 2ω _h . Finally, the AC component is filtered out by a low-pass filter, and the DC component is extracted to obtain an estimated position deviation signal f _c ( Δθ);

Step A.6), build a position deviation closed loop, use the estimated position deviation signal f _c (Δθ) as the input of the proportional resonance controller, and estimate the rotor angular velocity is the output of the proportional resonant controller, for the estimated rotor angular velocity Integrate to get the estimated rotor position;

Step A.7), repeat steps 1.1) to 1.6), until the estimated rotor position converges to a constant value, which is the initial estimated value of the initial rotor position.

As a further optimization scheme of the initial position detection method of a surface-mounted permanent magnet synchronous motor of the present invention, the detailed steps of judging the positive direction of the d-axis and obtaining the compensation value after the judgment of the positive direction of the d-axis are as follows:

Step B.1), divide an injected signal cycle (0,2π) into four intervals evenly: I: (0,π/2), II: (π/2,π), III: (π,3π/ 2) and IV: (3π/2,2π);

Step B.2), the d-axis high-frequency voltage response in intervals I and III Integrate, denoted as Among them, ω _h is the angular frequency of high-frequency current injection on the d-axis, and t represents the current moment;

Step B.3), judge the positive direction of the d-axis according to the sign of k _{I, III} , if k _{I, III} is less than 0, then the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after judging the positive direction of the d-axis is 0; if k _{I, III} is greater than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is π.

As a further optimization scheme of the initial position detection method of a surface-mounted permanent magnet synchronous motor of the present invention, the step of judging the positive direction of the d-axis and obtaining the compensation value after judging the positive direction of the d-axis can also be:

Step B.a), divide an injection signal period (0,2π) into four intervals evenly: I: (0,π/2), II: (π/2,π), III: (π,3π/2) and IV: (3π/2,2π);

Step Bb), integrate the d-axis high-frequency voltage response in intervals II and IV, denoted as Among them, ω _h is the angular frequency of high-frequency current injection on the d-axis, and t represents the current moment;

Step Bc), judge the positive direction of the d-axis according to the sign of k _{II, IV} , if k _{II, IV} is greater than 0, then the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is 0; If k _{II, IV} is less than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after judging the positive direction of the d-axis is π.

In the present invention, on the basis of using the pulse vibration high-frequency current injection method to realize the initial initial position estimation, an injection signal cycle is evenly divided into four intervals, and the d-axis high-frequency voltage response is integrated in intervals I and III, or in Integrate the d-axis high-frequency voltage response in intervals II and IV, and judge the positive direction of the d-axis according to the sign of the integral value. This method does not need to inject additional positive and negative pulse signals to judge the positive direction of the d-axis. The whole process only needs to inject a signal once. The reduced estimation time significantly simplifies the initial position detection process.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects:

(1) In the process of judging the positive direction of the d-axis, the injected current is always a sinusoidal high-frequency signal, and there is no need to inject positive and negative pulses, which simplifies the estimation process;

(2) Divide an injection signal cycle evenly into four intervals, integrate the d-axis high-frequency voltage response in intervals I and III, or integrate the d-axis high-frequency voltage response in intervals II and IV, according to this The sign of the integral value judges the positive direction of the d-axis, and the process can be completed within one cycle of the injected current signal, shortening the estimation time;

(3) It avoids the small inertia motor vibration problem that may be caused during the positive and negative pulse injection process, and can be used in occasions where the motor inertia is small and the rotor position vibration in the initial position estimation process has strict requirements.

Description of drawings

Figure 1 is a schematic block diagram of the initial position estimation process of the surface-mounted permanent magnet synchronous motor rotor;

Fig. 2 is a schematic diagram of the relative relationship between the two-phase stationary coordinate system, the actual two-phase synchronous rotating coordinate system and the estimated two-phase synchronous rotating coordinate system;

Fig. 3 is the functional block diagram of the signal extraction and modulation process of initial initial position estimation;

Fig. 4 is the functional block diagram of the signal extraction and modulation process of d-axis positive direction judgment;

Figure 5(a) corresponds to the simulation waveform of the initial rotor position estimation process when the actual rotor position is 1 rad;

Figure 5(b) corresponds to the waveforms of the judgment information k _{I, III} in the positive direction of the d-axis when the actual rotor position is 1rad;

Figure 5(c) corresponds to the waveforms of the judgment information k _{II and IV} in the positive direction of the d-axis when the actual rotor position is 1rad;

Figure 5(d) corresponds to the simulation waveform of the initial rotor position estimation process when the actual rotor position is 4rad;

Figure 5(e) corresponds to the waveforms of the judgment information k _{I, III} in the positive direction of the d-axis when the actual rotor position is 4rad;

Figure 5(f) corresponds to the waveforms of the judgment information k _{II, IV} in the positive direction of the d-axis when the actual rotor position is 4rad.

detailed description

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

As shown in Figure 1, the present invention provides a method for detecting the initial position of a surface-mounted permanent magnet synchronous motor, which specifically includes the following steps:

Step 1), establish the coordinate system relationship diagram, as shown in Figure 2, dq is the actual synchronous rotating coordinate system, In order to estimate the rotor synchronous rotating coordinate system, α-β is the actual two-phase stationary coordinate system, and define the estimated position error Among them, θ is the actual rotor initial position, is the final initial position estimate, The initial value of is 0;

Step 2), as shown in Figure 3, the q-axis current of the estimated rotor synchronous rotation coordinate system is given as 0, and the d-axis current is given as a pulse vibration high-frequency sinusoidal signal I _mh sin(ω _h t), where, I _mh is the amplitude of the high-frequency current injected on the d-axis, ω _h is the angular frequency of the high-frequency current injected on the d-axis, and t represents the current moment;

Step 3), using a proportional resonant controller (PR) to control the estimated d-axis current and q-axis current to make them consistent with the given;

Step 4), the output voltage of the PR regulator and Perform Park inverse transformation to obtain the voltages u _α and u _β in the two-phase static α-β coordinate system, and then use the space vector pulse width modulation strategy to obtain the six-way switching signals of the three-phase inverter to drive the surface-mounted permanent magnet synchronous motor SPMSM;

Step 5), detect any two-phase current in the three-phase winding A/B/C of the motor, first perform Clarke transformation to obtain the currents i _α and i _β in the two-phase static α-β coordinate system, and then obtain the estimated rotor through Park transformation d-axis current in synchronous rotating coordinate system and q-axis current Feed it back to the PR regulator;

Step 6), the q-axis voltage response of the rotor synchronously rotating coordinate system will be estimated The AC component with the frequency ω _h selected by the band-pass filter is the first harmonic component of the q-axis voltage response Then multiplied with the cosine signal cos(ω _h t) for modulation to obtain a DC component and an AC component with a frequency of 2ω _h . Finally, the AC component is filtered out by a low-pass filter, and the DC component is extracted to obtain an estimated position deviation signal f _c ( Δθ);

Step 7), build a position deviation closed loop, use the estimated position deviation signal f _c (Δθ) as the input of the PI regulator, and estimate the rotor angular velocity is the output of the PI regulator, the estimated rotor angular velocity Integrate to obtain the estimated rotor position, repeat steps 2-7 until the estimated rotor position converges to a constant value, which is the initial estimated value of the initial rotor position

Step 8), divide an injection signal cycle (0,2π) into four intervals evenly, namely: I: (0,π/2), II: (π/2,π), III: (π,3π /2) and IV: (3π/2,2π). As shown in Figure 4(a), the d-axis high-frequency voltage response in intervals I and III Integrate, denoted as The positive direction of the d-axis is judged according to the sign of k _{I, III} . If k _{I, III} is less than 0, the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after the judgment of the positive direction of the d-axis is 0, that is If k _{I, III} is greater than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is π, that is Alternatively, as shown in Fig. 4(b), the d-axis high-frequency voltage response is integrated over intervals II and IV, denoted as Judging the positive direction of the d-axis according to the sign of k _{II, IV} , if k _{II, IV} is greater than 0, the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after judging the positive direction of the d-axis is 0, that is If k _{II, IV} is less than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is π, that is

The theoretical analysis of judging the positive direction of the d-axis is as follows:

When the motor is at rest, the back EMF and cross-coupling items are both 0, and its d-axis voltage equation can be expressed as In the formula, R _s is the stator resistance, L _d (i _d ) means that the d-axis inductance is related to the actual d-axis current id, L _d (i _d > 0) means the corresponding _d -axis inductance when i _d > 0, L _d (id <0) represents the corresponding _{d-axis inductance when i d <} 0. In fact, when i _d >0, the d-axis inductance decreases due to the saturation of the d-axis magnetic field; when i _d <0, the d-axis inductance increases due to the desaturation of the d-axis magnetic field, and when i _d =0, the d-axis inductance is L _d0 , so that L _d (i _d >0)<L _d0 <L _d (i _d <0) can be obtained.

After the initial initial position estimation is completed, the rotor position estimation error Δθ is 0 or π, and the estimated d-axis current is consistent with the given value under the action of the PR regulator, namely The voltage equation to estimate the d-axis can be expressed as further calculated to get ${\hat{u}}_d=R_{\mathrm{the\; s}}{I}_{\mathrm{m\; h}}\sin \left({\mathrm{\&omega;}}_{h}t\right)+{\mathrm{\&omega;}}_h{L}_d\left(i_d\right)I_{\mathrm{m\; h}}\cos \left({\mathrm{\&omega;}}_{h}t\right).$

When the rotor position estimation error Δθ is 0, the estimated d-axis direction is consistent with the actual d-axis direction, and the estimated d-axis current is also consistent with the actual d-axis current. In the interval I: ω _h t ∈ (0, π/2), satisfy cos(ω _h t )>0. Therefore, ω _h L _d (i _d >0)I _mh cos(ω _h t)<ω _h L _d0 I _mh cos(ω _h t). In interval III: ω _h t ∈ (π,3π/2), satisfy L _d (i _d <0)>L _d0 , cos(ω _h t)<0. Therefore, ω _h L _d (i _d <0)I _mh cos(ω _h t)<ω _h L _d0 I _mh cos(ω _h t). and thus get:

${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; <</span>{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}$ ${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; <</span>{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}$

further calculated to get $k_{I.\mathrm{III}={\&Integral;}_0^{\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right)+{\&Integral;}_{\mathrm{\&pi;}}^{3\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right)<0.}$

Conversely, when the rotor position estimation error Δθ is π, the estimated d-axis direction is opposite to the actual d-axis direction, and the estimated d-axis current is also opposite in sign to the actual d-axis current. In the interval I: ω _h t ∈ (0, π/2), satisfy L _d (i _d <0)>L _d0 , cos(ω _h t)>0. Therefore, ω _h L _d (i _d <0)I _mh cos(ω _h t)>ω _h L _d0 I _mh cos(ω _h t). In interval III: ω _h t ∈ (π,3π/2), satisfy L _d (i _d >0)<L _d0 , cos(ω _h t)<0. Therefore, ω _h L _d (i _d >0)I _mh cos(ω _h t)>ω _h L _d0 I _mh cos(ω _h t). and thus get:

${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}$

${<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m\; h</span>}}$

further calculated to get $k_{I.\mathrm{III}={\&Integral;}_0^{\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right)+{\&Integral;}_{\mathrm{\&pi;}}^{3\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right)>0.}$

It can be seen that the estimated d-axis voltage response The sign of the integral value k _I.III on the interval I:ω _h t∈(0,π/2) and III:ω _h t∈(π,3π/2) can be used to judge the positive direction of the d-axis, if k _{I If .III} is less than 0, the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole; if k _I.III is greater than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole.

In the same way, it can be seen that the estimated voltage response of the d-axis Integral Values on Intervals II:ω _h t∈(π/2,π) and IV:ω _h t∈(3π/2,2π) The sign of can also be used to judge the positive direction of the d-axis. If k _II.IV is greater than 0, the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole; if k _II.IV is less than 0, the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole. reverse.

As shown in Fig. 5(a), Fig. 5(b) and Fig. 5(c), the corresponding actual rotor initial position is 1rad, and the positive direction judgment information of d-axis k _{I, III} is less than 0, k _{II, IV} is greater than 0, all Indicates that the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and there is no need to estimate the position for the first time Perform angle compensation, θ _c = 0; as shown in Figure 5(d), Figure 5(e) and Figure 5(f), the corresponding actual rotor initial position is 4rad, and the judgment information k _{I, III in} the positive direction of the d-axis is greater than 0 , k _{II, IV} less than 0, both indicate that the positive direction of the d-axis is opposite to the magnetic pole N, and the initial estimated position is required Compensate for π radians, θ _c = π, and the final initial position estimate is

Claims (3)

1. A surface mount type permanent magnet synchronous motor initial position detection method, is characterized in that, comprises the following steps: Step A), obtaining the initial estimated value of the rotor position; Step B), judging the positive direction of the d-axis, and obtaining the compensation value after judging the positive direction of the d-axis; Step B.1), divide an injection signal period (0,2π) into four intervals evenly: I: (0,π/2), II: (π/2,π), III: (π,3π/ 2) and IV: (3π/2,2π); Step B.2), the d-axis high-frequency voltage response in intervals I and III Integrate, denoted as $k_{I,III}={\&Integral;}_0^{\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right)+{\&Integral;}_{\mathrm{\&pi;}}^{3\mathrm{\&pi;}/2}{\hat{u}}_{d}d\left({\mathrm{\&omega;}}_{h}t\right),$ Among them, ω _h is the angular frequency of high-frequency current injection on the d-axis, and t represents the current moment; Step B.3), judge the positive direction of the d-axis according to the sign of k _{I, III} , if k _{I, III} is less than 0, then the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after judging the positive direction of the d-axis is 0; if k _{I, III} is greater than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is π; In step C), the initial estimated value of the rotor position is added to the compensation value after judging the positive direction of the d-axis to obtain the final estimated value of the initial position. 2. The surface-mounted permanent magnet synchronous motor initial position detection method according to claim 1, wherein the step of obtaining the initial estimated value of the rotor position is as follows: Step A.1), the q-axis current of the estimated rotor synchronous rotation coordinate system is given as 0, and the d-axis current is given as a pulse vibration high-frequency sinusoidal signal I _mh sin(ω _h t), where I _mh is at The amplitude of the high-frequency current injected on the d-axis, ω _h is the angular frequency of the high-frequency current injected on the d-axis, and t represents the current moment; Step A.2), using the proportional resonant controller PR to control the estimated d-axis current and q-axis current to make them consistent with the given; Step A.3), comparing the output voltage of the proportional resonant controller and Perform Park inverse transformation to obtain the voltages u _α and u _β in the two-phase static α-β coordinate system, and then use the space vector pulse width modulation strategy to obtain the six-way switching signals of the three-phase inverter to drive the surface-mounted permanent magnet synchronous motor ; Step A.4), detect any two-phase current in the three-phase winding A/B/C of the motor, first perform Clarke transformation to obtain the current i _α and i _β in the two-phase static α-β coordinate system, and then obtain Estimating the d-axis current in the rotor synchronously rotating coordinate system and q-axis current Feed it back to the proportional resonant controller; Step A.5), will estimate the q-axis voltage response of the rotor synchronously rotating coordinate system The AC component with a frequency of ω _h is selected through a band-pass filter, which is the first harmonic component of the q-axis voltage response Then multiplied with the cosine signal cos(ω _h t) for modulation to obtain a DC component and an AC component with a frequency of 2ω _h . Finally, the AC component is filtered out by a low-pass filter, and the DC component is extracted to obtain an estimated position deviation signal f _c ( Δθ); Step A.6), build a position deviation closed loop, use the estimated position deviation signal f _c (Δθ) as the input of the proportional resonance controller, and estimate the rotor angular velocity is the output of the proportional resonant controller, for the estimated rotor angular velocity Integrate to get the estimated rotor position; Step A.7), repeat steps 1.1) to 1.6), until the estimated rotor position converges to a constant value, which is the initial estimated value of the initial rotor position. 3. surface mount type permanent magnet synchronous motor initial position detection method according to claim 1, is characterized in that, in described step B), the step of judging d-axis positive direction and obtaining the compensation value after d-axis positive direction judgment is also can be: Step B.a), divide an injection signal cycle (0,2π) into four intervals evenly: I: (0,π/2), II: (π/2,π), III: (π,3π/2) and IV: (3π/2,2π); Step Bb), integrate the d-axis high-frequency voltage response in intervals II and IV, denoted as Among them, ω _h is the angular frequency of high-frequency current injection on the d-axis, and t represents the current moment; Step Bc), judge the positive direction of the d-axis according to the sign of k _{II, IV} , if k _{II, IV} is greater than 0, then the positive direction of the d-axis is in the same direction as the N pole of the magnetic pole, and the compensation value after the positive direction of the d-axis is judged is 0; If k _{II, IV} is less than 0, the positive direction of the d-axis is opposite to the N pole of the magnetic pole, and the compensation value after judging the positive direction of the d-axis is π.