1、A NON-LINEAR CONTROL ALGORITHM FOR IMPROVING PERFORMANCE OF WIND GENERATOR USING DOUBLY-FED INDUCTION GENERATOR INSTITUTE OF ELECTRICAL POWER ENGINEERING Chair Electric Drives and Basics of Electrical Power Engineering M.Sc.Phung,Ngoc LanAthens,Feb/Mar.2006A non-linear control algorithm for improvin
2、g performance of wind generator using doubly-fed induction generator Page 2IntroductionConventional control of doubly fed induction machine(DFIM)in wind generatorBased on the continuous or discreet model of DFIMDecoupling in active-and reactive power(P&Q)controlA voltage dip what happened?A new cont
3、rol scheme!Decoupling of P&Q is guarantedBetter performance in dynamical operation modeNon-linear control of DFIM with Exact-LinearizationCurrent model of DFIM is able to be exactly linearized!A new current controller is with only P-Type controllersThe complete control structure is simple.Decoupling
4、 is guaranteed-Direct-Decoupling“A non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 3Contents 1.DFIM Model and its characters.2.Conventional control of DFIM in wind generator3.Exact-Linearization“Concept and implementation with DFIM4.
5、Control structure with Direct-Decoupling“5.Conclusion and prospectsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 4Contents 1.DFIM Model and its characters.2.Conventional control of DFIM in wind generator3.Exact-Linearization“Conc
6、ept and implementation with DFIM4.Control structure with Direct-Decoupling“5.Conclusion and prospectsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 5Control system of DFIM in wind generator PM Powermodule;S Switch;L InductorMicroc
7、ontrollerMicrocontroller33PMPM3SDFIMnPMPMTransformerL LUdcUsUnIrIsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 6Demonstration of voltage-,flux-and current vector in d-q coordinatorusssj0,sdsqs u,0sdssquuuiuissssssrrrrrrdRjdtdRjd
8、tA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 71 111111()()1 111111()()11111rdrdr rqsdsqrdsdrssrmrqr rdrqsqsdrqsqrssrmsdrdsdssqsdssmsqrqssdsqssdiiiuudtTTTLLdiiiuudtTTTLLdiudtTTLdidtTT1sqmuLElectrical model of DFIM in d-q coordin
9、ator21msrLL L sssLTRrrrLTRA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 8u,Tssdsquu12BBBrrrElectrical model of DFIM in state-spacexAxB uB ussrrddtxi,TTrsrdrqsdsqii11122122AAAAAu,Trrdrquu12BBBsss-Rotor angular speed:Input variable
10、 of the model-Model of DFIM in state-space shows a bilinear systemA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 9Contents 1.DFIM Model and its characters.2.Conventional control of DFIM in wind generator3.Exact-Linearization“Conce
11、pt and implemetation with DFIM4.Control structure with Direct-Decoupling“5.Conclusion and prospectsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 10:ssmmagnetizing currentL Control variables of the active-and reactive power232(i)3
12、2ssdsdsMssdsdsp uiRmuip222cosisdsdssdsqiiii0ssdsdrdmLiiLssqsqrqsmLiiconstL The active power P and reactive power Q will be separately controlled through ird and irq A non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 11A control struct
13、ure of DFIM in wind generatorA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 12Contents 1.DFIM Model and its characters.2.Conventional control of DFIM in wind generator3.Exact-Linearization“Concept and implementation with DFIM4.Con
14、trol structure with Direct-Decoupling“5.Conclusion and prospectsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 13Why do we apply Exact-Linearization“?The nonlinear characters of DFIM Exact linearization guarantees not only the lin
15、earity between inputs and outputs but also the decoupling between each pair of input and output variable in the new model-noninteracting Performance of system in dynamical operation mode should be improved With the success of exact-linearization,different methods to design controllers for the new li
16、near model could be applied.A non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 14Exact-Linearization“the concept(1)Given a nonlinear MIMO-System with m inputs and m outputsxf(x)H(x)uyg(x)ddt1u;muu1x;nxx1ymyy 1xf xxnff 1xg xxmgg12H(x)h
17、(x)h(x)h(x)m then it is able to transfer the system in another state-space,where the linearity between the inputs and outputs is guaranted.Matrix L is invertible 1111111111(x)(x)L x(x)(x)mmmmrrhfhfrrhfmhfmL L gL L gL LgL Lg when the following conditions are satisfied:Sum of elements of vector of rel
18、ative degree12rmrrrn:n:jrNumber of state variablesRelative degree j-th A non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 15Exact-Linearization“the concept(2)With a coordinator transformation 11111111111xxxxzm xxxxxmmrrfmmnrmfmrmgmLgz
19、gzmLgm And with a state feedback controller1ua(x)L(x)w The new linear system will bezAzBwyCzddt A coordinator transformation Requirements of knowing the feedback of state variables The linearity between inputs and outputs is effective in the whole new state-spaceNotice A non-linear control algorithm
20、 for improving performance of wind generator using doubly-fed induction generator Page 161111111()()1111111()()rdrdr rqsdsqrdsdrssrmrqr rdrqsqsdrqsqrssrmrrdiiiuudtTTTLLdiiiuudtTTTLLddt Exact-Linearization“Implementation with DFIMConsidering three equations of DFIM11rsaTT1b1rcL1mdL1seTwith11222121331
21、2310010001rdrdr rqsdsqrdsdrqr rdrqsdsqrqsqrrxaxxdiaiiebcuduxaxuuxudtdixiaibecududtyddtyy 123100010001xxx,thenA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 17Exact-Linearization“Implementation with DFIM(1)The model in state-space
22、will be in form ofxf(x)H(x)uyg(x)with1111112222223333312213(x)x;y;g(x)(x);f(x)(x)0h(x)10H(x)h(x)01;h(x)001rdrqrxiyxgxaxxiyxgxaxxyxgxxx 123usdsqrdsdsdsqrqsqruebcuduubecuduuBy having Sum of elements of vector of relative degree:123r1 1 13rrr :jrRelative degree j-th Matrix L is invertible 22-1111010L x
23、01Lx01001001xxxxExact-linearization of the considering system can be implemented with the state feedback controller:1212110ua(x)L(x)w01w0010axxaxxA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 18Exact-Linearization“Implementation
24、with DFIM(2)In the new state-space,system will be:In detail:123000100wz000 z010 w,yw000001wyzdtordtdtzAzBwyCzddt The linearity between inputs and outputs.Decoupling between each channel defined as direct-decoupling The transfer function of the new system consists of only Integration elements The coo
25、rdinator transformation have only algebraic operationsNoticeA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 19Contents 1.DFIM Model and its characters.2.Conventional control of DFIM in wind generator3.Exact-Linearization“Concept an
26、d implementation with DFIM4.Control structure with Direct-Decoupling“5.Conclusion and prospectsA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 20v vStructure of the new linear modelA non-linear control algorithm for improving perfo
27、rmance of wind generator using doubly-fed induction generator Page 21Control system of DFIM in wind generator with direct-decouplingA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 22Circuit diagram with PlecsTmASMVdc2VCVvabvbcuaubu
28、cConvertVugrid_uvw 4VuVvVwvoltage dip3Rec Pulse4Inv Pulse5is_uvw5AAAus_uvw 6VvabvbcuaubucConvert1VSynch6mL7R Charge2AAAIt_uvw 3Start1AAir_klm1Amparameter7A non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 23Performance of linearized m
29、odel and current controllerwww123dtdtdt轾犏犏犏=犏犏犏犏臌y y0.20.30.40.50.60.70.80.91-5000500100015002000250030003500Time sIrd Irq w1 w2irdirqw1w2Performance of w1,y1(ird)and w2,y2(irq)irdirqw1w2123wywwdtdtdtPerformance of current controller1.11.151.21.251.31.351.4-60-50-40-30-20-10010203040Time sRotor curr
30、ent Airdirqirq*ird*ird*&irdirq*&irqA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 24Simulation:Grid voltage and electrical torque3.23.43.63.844.24.4-3000-2500-2000-1500-1000-50005001000Time sStator voltage V-Electrical Torque NmGr
31、id voltageGrid voltage50%50%75%75%100%100%Torque Linear ControlTorque Linear ControlTorque Nonlinear ControlTorque Nonlinear ControlA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 25Simulation:Active and reactive power 3.23.43.63.8
32、44.24.4-10123456x 105Time sActive W and reactive power VARP Linear ControlP Linear ControlP Nonlinear ControlP Nonlinear ControlQ Linear ControlQ Linear ControlQ Nonlinear ControlQ Nonlinear ControlA non-linear control algorithm for improving performance of wind generator using doubly-fed induction
33、generator Page 26Simulation:Rotor current3.23.43.63.844.24.4-400-2000200400600800Time sRotor current Aird Linear Controlird Linear Controlird Nonlinear Controlird Nonlinear Controlirq Linear Controlirq Linear Controlirq Nonlinear Controlirq Nonlinear ControlA non-linear control algorithm for improvi
34、ng performance of wind generator using doubly-fed induction generator Page 27Conclusion and perspectives Control system of DFIM with exact-linearization:practical and easy to implement.The simulation with Matlab/Simulink/Plesc shows good results,the complete control system is being verified on exper
35、iment rig Performance of system is improved with the static direct-decouplingdirect-decoupling current controller Advanced methods can be used in design process of controllersA non-linear control algorithm for improving performance of wind generator using doubly-fed induction generator Page 28Thank you for your attention!
