JP4096663B2 - Estimation value correction method and control system of induction motor magnetic flux estimator - Google Patents

Description

【０００４】
R_s：ステータ抵抗、R_r：ロータ抵抗、L_m：ロータ、ステータ相互コンダクタンス、L_s：ステータ自己インダクタンス、L_r：ロータ自己インダクタンス
ω_r：速度、ω_rest：速度推定値
g₁,g₂,g₃,g₄：オブザーバフィードバックゲイン
i_sa：ステータα相電流、i_sB：ステータβ相電流、V_a：ステータα相電圧、V_B：ステータβ相電圧
i_saest：ステータα相電流推定値、i_sBest：ステータβ相電流推定値
φ_raest：ロータα相界磁磁束推定値、φ_rBest：ロータβ相界磁磁束推定値
【０００５】
【数２】

【０００６】
上式に従って動作する誘導電動機制御回路用のオブザーバを用い、制御ステップkの推定値等により、制御ステップ(k+1)の推定値を算出する。すなわち、制御ステップkの制御ループで推定されたk・T_s秒時のα相電流推定値i_saest(k)とα相電流i_sa(k)との推定誤差
i_sa(k)- i_saest(k)
β相電流推定値i_sBest(k)とβ相電流i_sB(k)との推定誤差
i_sB(k)- i_sBest(k)
を用いて、(k+1)・T_s秒時の推定値i_saest(k+1)、i_sBest(k+1)、φ_raest(k+1)、φ_rBest(k+1)を算出する。
【０００７】
【発明が解決しようとする課題】
ところが従来の技術の誘導電動機磁束推定器においては、電圧センサを削除して、コストの削除を行うことが強く望まれる。これを実現しようとする１つの方法として、α相電圧指令値V_a ^*(k)、β相電圧指令値V_B ^*(k)をV_a(k)、V_B(k)の代わりに使用することが考えられる。
この場合、電圧指令値と実際値に誤差があることがあり、ロータ鎖交磁束φ_raest、φ_rBest及び、ω_restに誤差が生じるという問題があった。
そこで本発明は、α相電流推定値i_saest(k)とβ相電流推定値i_sBest(k)、位相推定量θ_1est(k)よりd軸電流推定値i_dest(k)を計算し、α相電流i_sa(k)とβ相電流i_sB(k)、位相推定量θ_1est(k)よりd軸電流i_d(k)を計算し、i_d(k)とi_dest(k)の差に補正ゲインを乗じた補正量をω_rest(k)、θ_1est(k)に加えることにより、精度良く速度推定及び、位相推定を行うことが出きる、誘導電動機磁束推定器を提供することを目的とする。
【０００８】
【課題を解決するための手段】
この課題を解決するため、本発明は従来の速度推定値ω_restに状態推定量i_saest(k)、i_sBest(k)と位相推定量θ_1est(k)より、下記の式
【０００９】
【数３】

【００１０】
e(k)：誘起電圧、θ₁：位相
のように実際の位相と位相推定量との誤差に相当することを利用して、以下に示す位相推定器を構成する。
【００１１】
【数４】

【００１２】
θ'_1est(k)とθ₁(k)が一致する時、上式のω'_rest(k)は実際の速度ω_r(k)に一致する。
【００１３】
【発明の実施の形態】
次に、本発明の実施例について図面を参照して説明する。
図1は、本発明の誘導電動機磁束推定器の推定磁束位相補正方法の一実施例が適用された誘導電動機の制御システムを示すブロック図である。
図1の制御システムブロック図について説明する。
速度指令ω_r ^*と速度推定値ω'_restが速度コントローラ1に入力され、速度コントローラ1は、q相電流指令i_q ^*を出力する。q相電流コントローラ2はi_q ^*とq相電流推定値i_qestとを入力し、q相電圧指令v_q ^*を出力する。一方d軸電流指令i_d ^*とd軸電流推定値i_destがd相電流コントローラ3に入力され、d相電流コントローラ3は、d相電圧指令v_d ^*を出力する。電圧指令v_q ^*とv_d ^*は、ベクトル制御演算回路4に入力され、位相補正器8より出力された位相θ'_1est、によりα相電圧指令v_a ^*、β相電圧指令v_B ^*に換算され出力される。
一方、磁束推定器7は、U相電流i_suとV相電流_isvを相変換器6を介して得られるα相電流i_sa、β相電流i_sBと電圧指令v_a ^*とv_B ^*を入力し、α相、β相電流推定値i_saest、i_sBest、ロータ鎖交磁束推定値φ_raest、φ_rBest、及び速度推定値ω_rest、位相推定値θ_1estを出力し、これら磁束推定器の出力を位相補正器8に入力し、補正後の速度推定値ω_rest、位相推定値θ_1est、d相電流推定値i_dest、q相電流推定値i_qestを出力する。
【００１４】
【発明の効果】
本発明によれば、位相推定値と電流推定値よりα-β相電流をd-q変換したd相電流推定値i_dest(k)と、位相推定値と電流検出値よりd-q変換したd相電流i_d(k)を計算し、d相電流とd相電流推定値の差に補正ゲインを乗じた補正量を速度推定値、位相推定値に加えたので、磁束推定器の推定値の精度が向上するという効果がある。
【図面の簡単な説明】
【図１】本発明の実施例の誘導電動機の入力電圧制御システムを表わすブロック線図である。
【符号の説明】
１ 速度コントローラ
２ q相電流コントローラ
３ d相電流コントローラ
４ ベクトル制御回路
５ インバータ回路
６ 相変換器
７ 磁束推定器
８ 位相補正器
９ 誘導電動機[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sensorless speed control method for a permanent magnet type synchronous motor.
[0002]
[Prior art]
The conventional induction motor flux estimator is a stator for at least two phases of the current supplied to the induction motor at the time of k · T _s seconds (k is an integer indicating the order of the control steps, T _s is the cycle of the control steps). By detecting the side current (for example, U-phase current i _su (k), V-phase current i _sv (k)) and the stator side voltage (for example, U-phase voltage V _su (k), V-phase voltage V _sv (k)) From the three-phase to two-phase conversion, the current and voltage are transformed into the α-β axis coordinate system normally used in vector control, and the α-phase current _isa (k) at k · T _s seconds, A β-phase current i _sB (k), an α-phase voltage V _a (k), and V _B (k) are calculated.
Formula (1) and speed estimation formula (2) of the magnetic flux estimator derived from the equation of state of the induction motor shown in D, Vol.III.No.11, p.954-960 (1991), phase The estimation formula (3) is as follows.
[0003]
[Expression 1]

[0004]
R _s: stator resistance, R _r: rotor resistance, L _m: rotor, stator transconductance, L _s: stator self-inductance, L _r: rotor self inductance omega _r: rate, omega _rest: speed estimation value
g ₁ , g ₂ , g ₃ , g ₄ : Observer feedback gain
i _sa : stator α-phase current, i _sB : stator β-phase current, V _a : stator α-phase voltage, V _B : stator β-phase voltage
i _saest : Estimated value of stator α-phase current, i _sBest : Estimated value of stator β-phase current φ _raest : Estimated value of rotor α-phase field magnetic flux, φ _rBest : Estimated value of rotor β-phase field magnetic flux
[Expression 2]

[0006]
Using the observer for the induction motor control circuit that operates according to the above equation, the estimated value of the control step (k + 1) is calculated from the estimated value of the control step k. That is, the estimation error between the estimated α phase current i _saest (k) and the α phase current i _sa (k) at k · T _s seconds estimated in the control loop of control step k
i _sa (k)-i _saest (k)
estimation error between the β-phase current estimated value _i sBest (k) and β phase current i _sB (k)
i _sB (k)-i _sBest (k)
_Is used to calculate the estimated values i _saest (k + 1), i _sBest (k + 1), φ _raest (k + 1), and φ _rBest (k + 1) at (k + 1) · T _s seconds. To do.
[0007]
[Problems to be solved by the invention]
However, in the induction motor magnetic flux estimator of the prior art, it is strongly desired to delete the cost by deleting the voltage sensor. One way to achieve this is to use α-phase voltage command value V _a ^* (k) and β-phase voltage command value V _B ^* (k) instead of V _a (k) and V _B (k) It is possible to do.
In this case, there is a case where there is an error between the voltage command value and the actual value, and there is a problem that an error occurs in the rotor linkage magnetic fluxes φ _raest , φ _rBest and ω _rest .
Therefore, the present invention calculates the d-axis current estimated value i _dest (k) from the α-phase current estimated value i _saest (k), the β-phase current estimated value i _sBest (k), and the phase estimated amount θ _1est (k), The d-axis current i _d (k) is calculated from the α-phase current i _sa (k), the β-phase current i _sB (k), and the phase estimation amount θ _1est (k), and i _d (k) and i _dest (k) Provide an induction motor flux estimator that can accurately perform speed estimation and phase estimation by adding a correction amount obtained by multiplying the difference between the two by a correction gain to ω _rest (k) and θ _1est (k) For the purpose.
[0008]
[Means for Solving the Problems]
In order to solve this problem, according to the present invention, the following equation is obtained from the state estimation amounts i _saest (k) and i _sBest (k) and the phase estimation amount θ _1est (k) in the conventional speed estimation value ω _rest.
[Equation 3]

[0010]
Using the fact that e (k) is an induced voltage and θ ₁ is equivalent to an error between an actual phase and a phase estimation amount, such as a phase, the following phase estimator is configured.
[0011]
[Expression 4]

[0012]
When θ ′ _1est (k) and θ ₁ (k) match, ω ′ _rest (k) in the above equation matches the actual speed ω _r (k).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an induction motor control system to which an embodiment of an estimated magnetic flux phase correction method for an induction motor magnetic flux estimator according to the present invention is applied.
The control system block diagram of FIG. 1 will be described.
The speed command ω _r ^* and the estimated speed value ω ′ _rest are input to the speed controller 1, and the speed controller 1 outputs a q-phase current command i _q ^* . The q-phase current controller 2 inputs i _q ^* and the q-phase current estimated value i _qest and outputs a q-phase voltage command v _q ^* . On the other hand, the d-axis current command i _d ^* and the estimated d-axis current value i _dest are input to the d-phase current controller 3, and the d-phase current controller 3 outputs the d-phase voltage command v _d ^* . The voltage commands v _q ^* and v _d ^* are input to the vector control arithmetic circuit 4 and output to the α-phase voltage command v _a ^* and β-phase voltage command v _B ^* by the phase θ ′ _1est output from the phase corrector 8. Converted and output.
On the other hand, the magnetic flux estimator 7, U-phase current i _su and V-phase current _isv phase converter 6 a α phase current obtained through the i _sa, beta phase current i _sB voltage command v _a ^* and v the _B ^* Input and output α-phase, β-phase current estimated value i _saest , i _sBest , rotor linkage flux estimated value φ _raest , φ _rBest , speed estimated value ω _rest , phase estimated value θ _1est, and output of these flux estimators The output is input to the phase corrector 8 and the corrected speed estimated value ω _rest , phase estimated value θ _1est , d-phase current estimated value i _dest , and q-phase current estimated value i _qest are output.
[0014]
【The invention's effect】
According to the present invention, the d-phase current estimated value i _dest (k) obtained by dq conversion of the α-β phase current from the phase estimated value and the current estimated value, and the d-phase current i converted by dq conversion from the phase estimated value and the current detected value. _d (k) is calculated and a correction amount obtained by multiplying the difference between the d-phase current and d-phase current estimated value by the correction gain is added to the speed estimated value and phase estimated value, so the accuracy of the estimated value of the magnetic flux estimator is improved. There is an effect of doing.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an input voltage control system for an induction motor according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Speed controller 2 q phase current controller 3 d phase current controller 4 vector control circuit 5 inverter circuit 6 phase converter 7 magnetic flux estimator 8 phase corrector 9 induction motor

Claims (2)

_Isa (k), β-phase current detected from stator-side currents i _su (k), i _sv (k) for at least two phases of the current supplied to the induction motor and converted to the α-β axis coordinate system i _sB (k) and the voltage command values V _a ^* (k) and V _B ^* (k) converted to the α-β axis coordinate system are input to the magnetic flux estimator, and the current estimated value i _saest (k + 1 ), I _sBest (k + 1), secondary side flux linkage estimate φ _raest (k + 1), φ _rBest (k + 1), velocity estimate ω _rest (k), phase estimate θ _1est (k ) In the magnetic flux estimator
Calculates d-phase current estimation value i _dest (k) obtained by dq conversion of α-β phase current from phase estimation value and current estimation value, and d-phase current i _d (k) obtained by dq conversion from phase estimation value and current detection value. The accuracy of the estimated value of the magnetic flux estimator is improved by adding a correction amount obtained by multiplying the difference between the d-phase current and the d-phase current estimated value by a correction gain to the speed estimated value and the phase estimated value. An estimated value correction method of an electric motor magnetic flux estimator. Speed command ω _r ^* And estimated speed ω ' _rest Enter the speed controller ( 1 )When, q Phase current command i _q ^* When q Phase current estimate i _qest And enter q Phase current controller ( 2 )When, d Axis current command i _d ^* When d Estimated shaft current i _dest Enter d Phase current controller ( Three )When, q Phase voltage command v _q ^* When d Phase voltage command v _d ^* Vector control arithmetic circuit ( Four ) And inverter circuit ( Five ) And phase corrector ( 8 )When,
  At least of the current supplied to the induction motor 2 Phase stator current i _su (k) , i _sv (k) Detect α - converted to β-axis coordinate system i _sa (k) , Β phase current i _sB (k) And α - Voltage command value converted to β-axis coordinate system V _a ^* (k) , V _B ^* ( k ) Magnetic flux estimator ( 7 ) And enter the current estimate i _saest (k + 1) , i _sBest (k + 1) , Secondary side flux linkage estimated value φ _raest (k + 1) , Φ _rBest (k + 1) , Speed estimate ω _rest (k) , Phase estimate θ _1est ( k ) Magnetic flux estimator ( 7 In an induction motor control system comprising
  From phase estimate and current estimate α - β-phase current d-q Converted d Phase current estimate i _dest (k) From the phase estimation value and current detection value d-q Converted d Phase current i _d (k) Calculate d Phase current and d A control system for an induction motor, wherein the accuracy of an estimated value of a magnetic flux estimator is improved by adding a correction amount obtained by multiplying a difference between phase current estimated values by a correction gain to a speed estimated value and a phase estimated value.

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