CN1756064A - Load torque control device and compensation process for synchronous reluctance motor - Google Patents

Abstract

The invention relates to a load torque control device of synchronous reluctance motor, which is used in the motor of compressor and not relative to the compressing pattern and the load mode, and via one algorism compensates the load torque, and the relative compensation method. The invention comprises: a load torque compensation part which utilizes the state variables of motor to calculate the load torque, and according to the calculated value to calculate the compensation current to be compensated to the load variable of said motor; a PI control part which outputs the reference torque current according to error between the reference speed and the actual rotary speed, the compensation current variable according to the load and applied by the load torque compensation part, and compensates the load torque. The invention can effectively reduce the vibration and noise of compressor which uses the motor and under the low-speed load character. And the invention can via a certain calculation method to calculate the compensation current which is not relative to the assembly accurateness of compressor, to carry out the accurate compensation control, while it can utilizes the same algorism to improve the control ability more under changed compression method.

Description

The load torque control device of synchronous magnetic resistance motor and compensation method

Technical field

The present invention relates to synchronous magnetic resistance motor, but particularly relate in compressor, use irrelevant and by load torque control device and compensation method (Load TorqueController and compensation method of Synchronous ReluctaneeMotor) with the synchronous magnetic resistance motor of a kind of algorithm compensating load torque with compress mode and load model.

Background technology

So-called synchronous magnetic resistance motor is rotor and the synchronous motor of stator drive source.In other words, behind the logical upward power supply, make the motor of the resistance minimum that produces on the rotor on the stator.

Particularly, in order to drive above-mentioned synchronous magnetic resistance motor, it is necessary grasping motor speed information or Magnetic Field.But, adopting as hole sensor or such velocity transducer or the magnetic field sensor of pulse converter, it is provided with, and the position is bad to be determined.And they are not durable under noisy environment to environment sensitive, and from seeing that economically price is also high.So being extensive use of does not recently have transducer can determine the control system of the synchronous magnetic resistance motor of rotor-position yet.

Fig. 1 shows the structure chart of general synchronous magnetic resistance motor.

General synchronous magnetic resistance motor is to be made of rotor (rotor) and stator (stator).The reference axis of determining the rotor orientation has d axle (d-axis) and q axle (q-axis).Stator has at interval the three-phase axle of 120 degree phase differences, and (w-axis), the magnetic field angle of rotor is by being benchmark with the u axle, and the angle of phase difference is represented between the d axle for u, v.

For the compressor of the synchronous magnetic resistance motor that uses above-mentioned formation, above-mentioned motor rotates once the variation that its compressor load has different mode.

Therefore, when carrying out speed control according to the load model motor rotating, the anglec of rotation of motor is with the load variations of compressor, but the output torque of motor still maintains on the average level of load, so cause the change of motor rotary speed, produce big vibration or noise thus.

Particularly, in the low cruise scope of motor, the amplitude of fluctuation of its rotary speed is bigger.So when low cruise, vibration or noise problem are the most obvious.

Fig. 2 shows the simple calcspar of the load torque control device structure of prior art.

Load torque control device according to the synchronous magnetic resistance motor of prior art comprises: consult dish (10); Receive the reference speed (ω) and the reckoning speed (ω of rotor ^*) relative error, and output replenishes the torque current of its error effect

PI (ProportionalIntegrator) control low (20).

The effect of consulting dish (10) is when the assemble compressible machine, to have guaranteed the relative position between rotor and the space part, and adjusted the phase relation between load change and the q axle offset current pattern.Can reflect according to the above-mentioned dish (10) of consulting, use the motor load pattern of specific compression mode.

Therefore, the load torque control device of the synchronous magnetic resistance motor of the prior art of above-mentioned formation be by, read load compensation q shaft current (i from the above-mentioned dish (10) of consulting to the mechanical location of rotor _{Q_Load} ^*), detect the speed of motor or electric current amplitude of fluctuation and with reference torque electric current from PI control part (10) output

It is worthwhile to carry out, and the load torque of small electromotor.

But, can reflect the motor load pattern of using the specific compression mode owing to consult dish (10), so, the load torque control device of above-mentioned synchronous magnetic resistance motor have under the abnormal load pattern, occur can't carry out the relevant inquiring problem of load compensation by consulting dish (10).

Fig. 3 shows the load model figure according to the rotor mechanical angle of general synchronous magnetic resistance motor.

As shown in Figure 3, for the compressor that uses synchronous magnetic resistance motor, can ANOMALOUS VARIATIONS according to its compress mode load model.So, when load model changes, need suitably revise the above-mentioned dish (10) of consulting according to its variation.

Also have, the above-mentioned dish (10) of consulting is provided with when the assemble compressible machine, compensation in the above described manner to load change depend on the assembling process of compressor to a great extent and consult the accuracy of dish (10).Therefore, if consult the data of dish (10) when error is arranged, the normally problem of the load torque of small electromotor can appear.

Summary of the invention

For overcoming and addressing the above problem, the purpose of this invention is to provide, utilize same algorithm, apply the load torque control device and the compensation method of the synchronous magnetic resistance motor of suitable load torque compensation electric current for the change of the load model under the multiple compress mode that is applied to compressor.

The load torque control device of synchronous magnetic resistance motor involved in the present invention comprises: utilize the variable of state value of motor to calculate load torque, calculate the load torque compensation portion of needs compensation to the offset current of the load change of motor by the torque value of calculating; Output is according to the reference torque electric current of error between the reference speed of motor and the actual rotary speed, the PI control part according to the offset current compensating load torque of load change by applying from load torque compensation portion.

The load torque compensation method of the synchronous magnetic resistance motor of the present invention's design comprises in addition: utilize the variable of state of electric rotating machine to calculate the 1st stage of exporting torque and torque constant; The 2nd stage of utilizing minimum repeatedly involution error approach (Recursive Least Square Error Method) to calculate the load torque of motor; The above-mentioned torque constant that differs from and calculate of above-mentioned load torque that utilization is calculated and output torque is calculated the load torque compensation electric current, and the torque current that observes by compensation comes the 3rd stage of compensating load torque.

The load torque control device of the synchronous magnetic resistance motor of the invention described above and compensation method significantly reduce vibration and the noise under the low speed load characteristic of the compressor that uses above-mentioned motor.And, calculated offset current by certain account form, irrelevant with the correct degree of assembling of compressor, can compensate control accurately.Under the situation of the compress mode of compressor change, also can utilize same algorithm, with further raising control ability.

Description of drawings

Fig. 1 is general synchronous magnetic resistance motor structure chart;

Fig. 2 is the simple calcspar of structure of the load torque control device of prior art;

Fig. 3 is the load model figure according to the rotor mechanical angle of general synchronous magnetic resistance motor;

Fig. 4 is the structure calcspar of load torque control device of the present invention;

Fig. 5 is the precedence diagram of the load torque compensation method of synchronous magnetic resistance motor of the present invention.

The symbol description of major part among the figure:

40: load torque compensation portion, 50: portion is calculated in the output torque,

60: offset current is calculated portion, the 70:PI control part,

81: the 1 worthwhile portions, 82: the 2 worthwhile portions.

Embodiment

Below, the embodiment that present invention will be described in detail with reference to the accompanying.

Fig. 4 is the calcspar according to load torque control device structure of the present invention.

As shown in the figure, the load torque control device of synchronous magnetic resistance motor of the present invention comprises: utilize the variable of state value of motor to calculate load torque, calculate the load torque compensation portion (40) of needs compensation to the offset current of the load change of motor by the torque value of calculating; Output is according to the reference torque electric current of error between the reference speed of motor and the actual rotary speed, the PI control part (40) according to the offset current compensating load torque of load change by applying from load torque compensation portion; The 2nd worthwhile (82) according to the offset current compensating load torque of load change that utilization applies from load torque compensation portion (40);

Also have, load torque control device also comprises, reference speed of more above-mentioned rotor (ω) and reckoning speed (ω ^*), its error amount is applied to the 1st worthwhile (81) of PI control part (20).

Above-mentioned load torque compensation portion (4O) comprises, utilizes the variable of state value of motor to calculate the output torque (T of motor _e) and torque constant (K _T) the output torque calculate portion (50); By calculating the output torque (T that portion (50) calculates from the output torque _e) and the rotary speed (ω) of motor extrapolate the load torque of above-mentioned motor

, utilize the load torque of extrapolating

With the torque constant (K that calculates _T) offset current of calculating the load torque compensation electric current calculates portion (60)

The output torque is calculated portion (50) magnetic field and current value according to the rotor angle axle is input to the output torque (T that draws motor in the specific computing formula _e) and torque constant (K _T).Here, calculate output torque (T _e) and torque constant (K _T) computing formula, as follows:

Computing formula 1

$T_e\left(n\right)=\frac{3P}{22}({\mathrm{\λ}}_d\left(n\right)i_q\left(n\right)-{\mathrm{\λ}}_q\left(n\right)i_d\left(n\right))$

$K_T\left(n\right)=\frac{T_e\left(n\right)}{i_q\left(n\right)}$

Also have, offset current is calculated portion (60) and is utilized from the output torque to calculate the output torque (T that portion (50) calculates _e) and torque constant (K _r) calculate load torque .At this moment, the method for calculating above-mentioned load torque utilizes repeatedly minimum involution error approach (RecursiveLeast Square Error Method) to calculate.Concrete computing formula is as follows:

Computing formula 2

$\widehat{\mathrm{\ω}}\left(n\right)=\left[\begin{array}{ccc}\hat{a}(n-1)& \hat{b}(n-1)& \hat{c}(n-1)\end{array}\right]\left[\begin{array}{c}w(n-1)\\ T_e(n-1)\\ 1\end{array}\right]={\widehat{\mathrm{\Θ}}}^T(n-1)\mathrm{\Φ}\left(n\right)$

$e(\widehat{\mathrm{\Θ}}(n-1),n)=\mathrm{\ω}\left(n\right)-\widehat{\mathrm{\ω}}\left(n\right)$

$\widehat{\mathrm{\Θ}}\left(n\right)=\widehat{\mathrm{\Θ}}(n-1)+\frac{P(n-1)\mathrm{\Φ}\left(n\right)e(\widehat{\mathrm{\Θ}}(n-1),n)}{\mathrm{\ρ}+{\mathrm{\Φ}}^T\left(n\right)P(n-1)\left(n\right)},{\widehat{\mathrm{\Θ}}}_0$

$P\left(n\right)=\frac{1}{\mathrm{\&rho;}}\{P(n-1)-\frac{P(n-1)\mathrm{\&Phi;}\left(n\right){\mathrm{\&Phi;}}^T\left(n\right)P(n-1)}{\mathrm{\&rho;}+{\mathrm{\&Phi;}}^T\left(n\right)P(n-1)\mathrm{\&Phi;}\left(n\right)}\},{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="A20041007219500092.png,A20041007219500101.png"\; state="\{\{state\}\}">P</figure-callout>}}_0=P_0^T>0$

(0＜ρ＜1 ρ: coefficient forgettingfactor)

${\hat{T}}_L\left(n\right)=-\frac{\hat{c}\left(n\right)}{\hat{b}\left(n\right)}$

So, if calculating the output torque (T that portion (50) calculates from above-mentioned output torque _e) and the observation speed (ω) of above-mentioned motor be input in the aforementioned calculation formula and go, appear at the load torque of electric rotating machine at last

Also have, it is the load torque of utilizing the motor of calculating by said process that above-mentioned offset current is calculated portion (60) With calculate the torque constant (K that portion (50) calculates from above-mentioned output torque _T), can calculate load torque compensation electric current (i _{Q_Load} ^*).

At this moment, calculate above-mentioned load torque compensation electric current (i _{Q_Load} ^*) computing formula, as follows:

[computing formula 3]

${i^{*}}_{q-\mathrm{Load}}\left(n\right)=G_{\mathrm{comp}}\frac{\widehat{T_L}\left(n\right)T_e\left(n\right)}{K_T\left(n\right)}$

Here, load compensation coefficient (G _Comp) expression, regulate above-mentioned load torque

Degree of compensation.

As the startup principle of the present invention of above-mentioned formation, as follows:

Fig. 5 is the precedence diagram of the load torque compensation method of synchronous magnetic resistance motor of the present invention.

At first, the rotor rotating coordinate system d that observes at motor, the magnetic field on the q axle utilizes the magnetic field observe and the current value of mensuration to calculate output torque and torque constant then.(S1，S2)

Output torque and torque constant are the observation magnetic field on rotor rotating coordinate system d, the q axle and mensuration current value to be input in the computing formula 1 calculate.

Then, calculate output torque after, utilize minimum repeatedly involution error approach to calculate the load torque of motor.The aforementioned calculation method is to utilize computing formula 2.(S3)

After calculating the load torque of motor, the offset current portion of calculating utilizes load torque of calculating and the torque constant of being calculated by the output torque portion of calculating, and calculates the load torque compensation electric current on the q axle.(S4)

Then, it is worthwhile that the instruction current value on the offset current of being calculated by the offset current portion of calculating and the q axle of being calculated by PI control part (70) is carried out together, utilizes the poor compensating load torque between the current value on the q axle of final worthwhile current value that goes out and mensuration.(S5)

The load torque control device and the compensation method of synchronous magnetic resistance motor of the invention described above that utilized description of drawings.But the present invention not only is confined to the content put down in writing on embodiment and the accompanying drawing, but as long as of the present invention irrelevant with compress mode and load model, by in the technological thought protection range with the torque of a kind of algorithm compensating load, but flexible Application.

Claims (6)

1, a kind of synchronous magnetic resistance motor load torque control device is characterized in that comprising: utilize the variable of state value of motor to calculate load torque, calculate the load torque compensation portion of needs compensation to the offset current of the load change of motor by the torque value of calculating; Output is according to the reference torque electric current of error between the reference speed of motor and the actual rotary speed, the PI control part according to the offset current compensating load torque of load change by applying from load torque compensation portion.

2, synchronous magnetic resistance motor load torque control device according to claim 1 is characterized in that, load torque compensation portion comprises: utilize the variable of state value of motor to calculate the output torque of motor and portion is calculated in the output torque of torque constant; Extrapolate the load torque of motor by the rotary speed of the output torque of calculating from the output torque portion of calculating and motor, the offset current that utilizes load torque of extrapolating and the torque constant of calculating to calculate the load torque compensation electric current is calculated portion.

3, synchronous magnetic resistance motor load torque control device according to claim 2, it is characterized in that, the offset current portion of calculating is a computing formula of utilizing repeatedly minimum involution error approach (Recursive LeastSquare Error Method), the speed of output torque and motor is embodied calculate load torque in the following computing formula:

$\widehat{\mathrm{\&omega;}}\left(n\right)=\left[\begin{array}{ccc}\hat{a}(n-1)& \hat{b}(n-1)& \hat{c}(n-1)\end{array}\right]\left[\begin{array}{c}w(n-1)\\ T_e(n-1)\\ 1\end{array}\right]={\widehat{\mathrm{\&Theta;}}}^T(n-1)\mathrm{\&Phi;}\left(n\right)$

$e(\widehat{\mathrm{\&Theta;}}(n-1),n)=\mathrm{\&omega;}\left(n\right)-\widehat{\mathrm{\&omega;}}\left(n\right)$

$\widehat{\mathrm{\&Theta;}}\left(n\right)=\widehat{\mathrm{\&Theta;}}(n-1)+\frac{P(n-1)\mathrm{\&Phi;}\left(n\right)e(\widehat{\mathrm{\&Phi;}}(n-1),n)}{\mathrm{\&rho;}+{\mathrm{\&Phi;}}^T\left(n\right)P(n-1)\mathrm{\&Phi;}\left(n\right)},{\widehat{\mathrm{\&Theta;}}}_0$

$P\left(n\right)=\frac{1}{\mathrm{\&rho;}}\{P(n-1)-\frac{P(n-1)\mathrm{\&Phi;}\left(n\right){\mathrm{\&Phi;}}^T\left(n\right)P(n-1)}{\mathrm{\&rho;}+{\mathrm{\&Phi;}}^T\left(n\right)P(n-1)\mathrm{\&Phi;}\left(n\right)}\},P_0=P_0^T>0$

(0＜ρ＜1 ρ: coefficient forgettingfactor)

${\hat{T}}_L\left(n\right)=-\frac{\hat{c}\left(n\right)}{\hat{b}\left(n\right)}$

4, synchronous magnetic resistance motor load torque control device according to claim 2 is characterized in that, the output torque portion of calculating is input to the variable of state value of motor to calculate output torque and torque constant in the following computing formula:

$\mathrm{Te}\left(n\right)=\frac{3P}{22}({\mathrm{\&lambda;}}_d\left(n\right)i_q\left(n\right)-{\mathrm{\&lambda;}}_q\left(n\right)i_d\left(n\right))$

$K_T\left(n\right)=\frac{T_e\left(n\right)}{i_q\left(n\right)}$

5, synchronous magnetic resistance motor load torque control device according to claim 3 is characterized in that, the offset current portion of calculating is input to the load torque calculated and output torque and torque constant to calculate the load torque compensation electric current in the following computing formula:

${I^{*}}_q-\mathrm{Load}\left(n\right)=G_{\mathrm{comp}}\frac{{\hat{T}}_L\left(n\right)T_e\left(n\right)}{K_T\left(n\right)}$

6, a kind of load torque compensation method of utilizing the load torque control device of the described synchronous magnetic resistance motor of claim 1 is characterized in that comprising: utilize the variable of state of electric rotating machine to calculate the 1st stage of exporting torque and torque constant; The 2nd stage of utilizing minimum repeatedly involution error approach (Recursive Least Square Error Method) to calculate the load torque of motor; The torque constant that differs from and calculate of load torque that utilization is calculated and output torque is calculated the load torque compensation electric current, and the torque current that compensation observes comes the 3rd stage of compensating load torque.

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