郭云云
(重慶師范大學(xué)數(shù)學(xué)學(xué)院,重慶 401331)
基于比較系統(tǒng)的永磁同步電機(jī)的脈沖穩(wěn)定性*
郭云云
(重慶師范大學(xué)數(shù)學(xué)學(xué)院,重慶 401331)
永磁同步電動(dòng)機(jī)具有體積小,損耗低,效率高等優(yōu)點(diǎn),在節(jié)約能源和環(huán)境保護(hù)日益受到重視的今天,對(duì)其研究就顯得非常必要;然而與普通的非線(xiàn)性系統(tǒng)相比,永磁同步電機(jī)對(duì)外部負(fù)載擾動(dòng)和參數(shù)變化非常敏感,因此主要通過(guò)脈沖控制方法來(lái)探究永磁同步電機(jī)的穩(wěn)定性問(wèn)題,得出了其漸進(jìn)穩(wěn)定的充分條件,并通過(guò)具體實(shí)例來(lái)驗(yàn)證結(jié)果的有效性.
永磁同步電機(jī);脈沖控制;漸進(jìn)穩(wěn)定
永磁同步電機(jī)的脈沖控制模型:
模型(1)中,id,iq分別為d-q軸電流;Ld,Lq分別為d-q軸定子電感;R1表示定子繞阻;ω表示轉(zhuǎn)子角頻率;TL表示外部轉(zhuǎn)矩;ψr表示永久磁通;np表示極對(duì)數(shù);β表示粘性阻尼系數(shù);J表示轉(zhuǎn)動(dòng)慣量.
通過(guò)仿射變換和時(shí)間尺度變換,將模型(1)變換成無(wú)量綱的狀態(tài)方程.即,其中:
則無(wú)量綱的狀態(tài)方程為
考慮氣隙均勻的永磁同步直線(xiàn)電動(dòng)機(jī)混沌模型,即Ld=Lq=L,考慮其中參數(shù)的不確定性,并設(shè) x=,則氣隙均勻的參數(shù)不確定永磁同步電動(dòng)機(jī)混沌數(shù)學(xué)模型可寫(xiě)為
其矩陣表示如下:
定義1 令V:R+×Rn→R+,稱(chēng)V屬于V0,如果:
(1)V在區(qū)間(τi-1,τi]×Rn上連續(xù),且對(duì)任一存在;
(2)V關(guān)于X滿(mǎn)足局部Lipschitz條件.
定義2 考慮如下的脈沖控制系統(tǒng)
令V∈V0,并且滿(mǎn)足,其中g(shù):R+×R→R,在區(qū)間(τk-1,τk]×R上連續(xù),且對(duì)任一)存在;ψk是R+→R+上的不減函數(shù),則系統(tǒng):
稱(chēng)為系統(tǒng)(5)的比較系統(tǒng).
定理1[1]對(duì)系統(tǒng)(5),如果
(1)f(t,0)=0,u(t,0)=0,g(t,0)=0,對(duì)所有k滿(mǎn)足U(k,0)=0;
(2)V:R+×Sρ→R+,ρ>0,V∈V0,d+V(t,x)≤g(t,V(t,x)),t≠τk;
(3)存在一個(gè)ρ0>0,則對(duì)所有k,x∈ρ0蘊(yùn)含著x+U(k,x)∈Sρ,且V(t,x+U(k,x))≤ψk(V(t,x)),t=τk,x∈Sρ0;
(4)在R+×Sρ上滿(mǎn)足上的連續(xù)且嚴(yán)格遞增函數(shù),K(0)=0),則比較系統(tǒng)(6)平凡解的穩(wěn)定性蘊(yùn)含系統(tǒng)(5)的平凡解的相應(yīng)的穩(wěn)定性.
考慮帶有脈沖控制的永磁同步電機(jī)模型:
定理2 令P是n×n對(duì)稱(chēng)正定矩陣,λ1>0,λ2>0分別為P的最小與最大特征值;令Q=PA+ATP;q,d分別為矩陣P-1Q,P-1(I+BT)P(I+B)的最大特征值,0≤δk=τk-τk-1<∞(k=1,2,…)為脈沖間距,則系統(tǒng)(3)是漸進(jìn)穩(wěn)定的,如果存在一個(gè)常數(shù)γ>1滿(mǎn)足:qδk≤-ln(γd).
證明 令V(t,x)=xTPx,則當(dāng)t≠τ時(shí)
當(dāng)t=τi時(shí),V((τi,x+Bx))=xT(I+BT)P(I+B)x≤dV(τi,x),則定理1的條件3就滿(mǎn)足了,且ψk(ω)=dω.
令ω(t)為系統(tǒng)(6)在滿(mǎn)足初始條件ω(τ+0)=ω0的任一解,則可以得出:
當(dāng)t∈(τk,τk+1]時(shí),ω(t)=dkω(τ0)exp(q(t-τ0)),又qδk≤-ln(γd),即dexp(qδk)≤1 γ,則:
而γ>1,故當(dāng)t→∞時(shí),k→∞,ω(t)→0,定理得證.
考慮如下的參數(shù)不確定的永磁同步電機(jī)
圖1 未加控制狀態(tài)
圖2 加入脈沖控制狀態(tài)
δk=δ=0.1,γ=1.3,則qδk≤-ln(γd)滿(mǎn)足,加入脈沖控制后,其狀態(tài)見(jiàn)圖2,從圖2可知,系統(tǒng)在定理所示的條件下是穩(wěn)定的.
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Impulsive Stability of Permanent Magnetic Synchronous Motor Based on Comparative System
GUO Yun-yun
(School of Mathematics,Chongqing Normal University,Chongqing 401331,China)
It's necessary to researth permanent magnetic synchronous motor with the advantages such as small volume,low wastage,high efficiency and so on,because energy conservation and environment protection are currently more and more emphasized.Compared with common nonlinear system,however,the permanent magnetic synchronous motor is very sensitive to external load perturbation and parameter change,thus,the stability of permanent magnetic synchronous motor is studied mainly by impulsive control method,the sufficient condition for its asymptotic stability is obtained,and the validity of the results is verified by real examples.
permanent magnetic synchronous motor;impulsive control;asymptotic stability
O192.1
A
1672-058X(2015)02-0001-04
10.16055/j.issn.1672-058X.2015.0002.001
責(zé)任編輯:田 靜
2014-07-18;
2014-09-18.
國(guó)家自然科學(xué)基金(61302180);重慶市教委基金資助(KJ130606).
郭云云(1989-),女,山西臨汾人,碩士研究生,從事微分方程與動(dòng)力系統(tǒng)方向研究.