Research on control algorithm of high voltage circuit breaker three phase permanent magnet brushless DC motor

Transcription

1 4th Internatonal Conference on Mechancal Materals and Manufacturng Engneerng (MMME 06) Research on control algorthm of hgh voltage crcut breaker three phase permanent magnet brushless DC motor Fucheng Lang Electrc Power Research Insttute of State Grd Laonng Electrc Power Co., Ltd., Shenyang, Laonng, 0006, Chna Hgh Voltage and Large Current Laboratory of State Grd Corporaton, Shenyang, Laonng, 0006, Chna Hongku Zhang CCTEG Shenyang Research Insttute, Fushun, Laonng,, Chna ABSTRACT: Amng at the hgh voltage crcut breaker three-phase permanent magnet brushless DC motor, ths paper studes the moton characterstcs of the motor operatng mechansm under dfferent control strateges. Consderng the swtchng operaton process of hgh voltage crcut breaker, we establshed the permanent magnet brushless DC motor operatng mechansm moton smulaton model of the control system. It was controlled by the dgtal double closed loop and the nner s current loop, where a PI controller s adopted. The outer rng s speed rng, whch was controlled by two dfferent control strateges, the tradtonal PID controller and sngle neuron PID controller. Through the smulaton analyss of servo control system, the trackng control performance of the motor operatng mechansm s obtaned. The results show that the sngle neuron PID controller can acheve better trackng control of the contact speed, makng t movng by the deal moton characterstc curve. It s an deal and effectve control method. KEYWORD: hgh voltage crcut breaker; brushless DC motor; tradtonal PID controller; sngle neuron PID controller complex transmsson mechansm. It has lttle movement parts and small movement dsperson. The development of power electroncs technology and modern control theory has realzed the precse control of motor speed, whch provdes the possblty for the relable control of the hgh voltage crcut breaker brushless DC motor operatng mechansm. INTRODUCTION In power system, the breaker nterruptng capacty has great dfference due to the hgh voltage crcut breaker has dfferent actual crcut parameters under dfferent workng state of the power system (such as no-load, load and short crcut fault). Dfferent voltage level crcut breakers have dfferent openng and closng characterstcs n the same workng condton. Tradtonal hgh voltage crcut breaker operatng mechansm adopts sprng, hydraulc or pneumatc technology, whch has many connectng rods and complcated structure, the cumulatve movement tolerance s large and the response s slow. It s dffcult to acheve relable control of the contact movement. The crcut breaker stroke s very short and openng and closng tme s only a few tens of ms. The speedness and controllablty of operatng mechansm are drectly related to whether the contact can be acted by the predetermned speed curve and the nterruptng capacty and relablty of breaker. The permanent magnet brushless DC motor operatng mechansm connected the motor spndle wth the operatng rod, whch can drectly drve crcut breaker man shaft movng and remove the 06. The authors - Publshed by Atlants Press PERMANENT MAGNET BRUSHLESS DC MOTOR. Overall structure Ths paper ams at 40.5 kv vacuum crcut breaker developed a permanent magnet brushless DC motor operatng mechansm, as shown n Fgure. The motor operatng mechansm and nsulatng pull rod n arc extngush chamber are connected by a set of a four bar lnkage mechansm, whch composed by a rotatng shaft, a crank arm, a sprng contact, nsulatng pull rod and a trangular turn arm. The operatng mechansm of the motor s drven by the four connectng rod mechansm to drve the nsulatng pull rod to realze the openng and closng operaton of the crcut breaker. 89

2 Fg structure drawng of permanent magnet brushless DC motor operatng mechansm. Mathematcal model The overall structure of the permanent magnet brushless DC motor of hgh voltage crcut breaker s shown n Fgure, whch s manly composed of a permanent magnet brushless DC motor, a lmt devce and a photoelectrc encoder. The drvng moton of hgh voltage crcut breaker s generated by the motor body and t can acheve the hold functon by usng the lmt devce n openng and closng poston. Meanwhle, photoelectrc encoder s adopted to detect the rotor poston and provde poston feedback for servo system to realze the precse control of motor moton process. Fg structure drawng of permanent magnet brushless DC motor In order to hghlght the man problems n the analyss of the dynamc mathematcal model of the brushless DC motor, we do the followng assumptons: the stator wndng s 60 phase wth full ptch concentrated wndng, Y-type connecton; neglect of magnetc saturaton, regardless of hysteress and eddy current losses; rotor wthout dampng wndng, permanent magnet not forms the dampng effect; 4 wthout consderng the armature reacton, the ar gap magnetc feld dstrbuton s a trapezodal wave, wde flat top s0 electrcal degrees. () Torque equaton θp s coordnates poston at a certan pont on ar gap crcumference, θ s rotor angular dsplacement wth respect to the orgnal poston. The magnetc nducton ntensty of rotor n the ar gap crcumference θp s: Br( p, ) Bm f( p ) () In the above equaton, Bm s magnetc flux densty ampltude; f (θ) s the dstrbuton functon of rotor flux densty, whch form s determned by the structure of the motor and ts value s merely nfluenced by stator and rotor relatve poston (θpθ). At the same tme, t s obvous that f s a perodc functon due to the symmetry structure of the motor. Accordng to the structure of the motor, the magnetc nducton ntensty generated by rotor on crcumference ar gap of each phase wndng can be obtaned. Thus, the electromagnetc force of conductors s as follows: Ta nrbala labm T nrb l l B f 60 () b b b b m Tc nrbclc lcbm f 0 In the above equaton, Ta, Tb, Tc s electromagnetc torque of each phase wndng, a, b, c s current n the conductor, l s the effectve length of conductor. () Electrc potental balance equaton The counter electromotve force of each phase wndng s shown as followngs: ea Balv lrbm f eb Bblv lrbm 60 ec Bclv lrbm 0 () In the above equaton, r s the effectve radus of motor rotor; w s angular velocty of rotor. The electrc potental balance equaton s shown as followngs. ua L M M a r 0 0a ea u b M L M P b 0 r 0 b eb u M M L 0 0 r c c c e c (4) In the above equaton, L s the self nductance of each phase wndng (H); M s the mutual nductance between the two phases; P s dfferental operator P =d/dt. () Motor knematc equaton Motor knematc equatons satsfy the followng equaton: d Tem Tl J dt d dt (5) In the above equaton, Tem s electromagnetc torque; T s load torque; J s rotatonal nerta of rotor; θ s revolvng angels of motor CONTROL STRATEGY AND METHOD RESEARCH The openng and closng operaton movement of hgh voltage crcut breaker s a process of short tme, large nerta, nonlnear and varable load. Amng at motor operatng mechansm control strategy analyss and based on the tradtonal PID 80

3 control theory, the ntellgent control theory s ntroduced n ths paper.. Speed characterstcs of the motor under the control of tradtonal PID In dgtal double closed loop of the hgh voltage crcut breaker movng contact movement control, the speed adjustment uses the ncremental PID control algorthm to obtan the best dynamc effect. The output speed s the reference value of the current, and the calculaton formula s as follows: Iref ( k) Iref ( k) ( KPI KIITI KDI / TV ) e( k) (6) ( K K / T ) e( k) K e( k)/ T PI DI V DI V In the above equaton, Iref(k) s speed adjustment output and the current adjustment reference value; KPI s velocty rato coeffcent; KII s velocty ntegral coeffcent; KDI s dfferental coeffcent of velocty; TV s samplng perod of speed; e(k) s rate devaton for the K tmes. The regulaton of current s a new process of PWM producton. The average value of current can be adjusted by adjustng the wdth of the PWM waveform, and the wdth of the PWM waveform s acheved by adjustng DSP event manager and the comparson value of the COMP event manager. Its algorthm formula s as follows: COMP( k) COMP( k ) KPV[ e( k) e( k )] SK T e( k) IV I (7) In the above equaton, COMP(k) s current adjustment output; e(k) s current devaton; KPV s current rato coeffcent; KIV current ntegral coeffcent; S s ntegral separaton swtch, f e(k) <ξ, S=. If e(k) ξ, S=0; T s current regulaton perod Amng at the openng and closng process of hgh voltage crcut breaker, the modelng of the brushless DC motor actuator control system was establshed. The system smulaton model s shown n Fgure. Fg Smulaton module of control system usng routne PID controller The smulaton results are shown n fgure 4. From the results, we can see that system at later perod has a bg devaton. The tradtonal PID controller n orgnal system s replaced by sngle neuron adaptve PID controller and fuzzy adaptve PID controller and other ntellgent controllers n outer loop speed regulatng devce of the system. The hope s that through the further mprovement of the control algorthm to mprove the effectveness of the trackng. (a) Closng process (b) Operatng process Fg4 Smulaton curve of speed trackng control usng routne PID controller. Temperature Rse Sngle neuron adaptve controller acheves the adaptve functon by adjustng the regulator weghts of proporton, ntegral, dfferental. The adjustment of the weght coeffcent s based on supervsed Hebb learnng rule. Neurons have nput varables x (k) (=,, ), the nput of the converter reflects the devaton state of desred output and the controlled gven. If settng gven s yr (k), output s y (k), devaton s e (k), and x, X, X s the requred state after the converter nto neuron learnng control, where x = e (k), x (k) = Δ e (k), X (k) = e(k) -e (k-) + e (k-), Z (k) = e (k). They are performance ndexes. Neurons produce control sgnal by an assocatve search, namely the output sgnal u(k) of adaptve neuron s: uk uk K w k x k (8) 8

4 Among t: w(k) s the correspondng weghts coeffcent of x(k), K s proportonalty coeffcent of neurons, K>0. yk uk s usually unknown n PID control algorthm, yk uk s used nstead. The resultng mprecse effects can be compensated by adjustng the learnng rate η. After the normalzaton of the above algorthm, the learnng algorthm s as follows: shown n Fgure 6. From the smulaton results, we can see that system speed trackng s mproved to some extent, but trackng error s large at hgh speed. For applcatons of crcut breaker movng contact movement control, sngle neuron PID has some dsadvantages n terms of stablty and accuracy. It should be combned wth other control algorthms, such as ntroducng feed forward controller based on orgnal sngle neuron PID controller to mprove the dsadvantages of poor rapdty and bg overshoot or other control algorthms. u w w w w ' k u k K w k x k ' w k k,,, w k k w k Kz k x k k w k Kz k x k k w k Kz k x k x, x 0, x 0 I P D y k u k y k u k y k u k (9) Based on the permanent magnet brushless DC motor and the establshed sngle neuron controller model, and amng at the openng and closng process of hgh voltage crcut breaker, the modelng of contact moton control system was establshed here. System structure s shown n Fgure 5. (a) Closng process (b) Operatng process Fg6 Smulaton curve of speed trackng control usng sngleneuron PID controller Fg5 The structure chart of of speed trackng system usng sngle-neuron PID controller 4 SIMULATION ANALYSIS OF HIGH VOLTAGE CIRCUIT BREAKER THREE PHASE MOTOR MECHANISM IN COAL MINE 4. Smulaton of motor mechansm The sngle neuron PID controller s embedded n the contact moton control system to nstead of the tradtonal PID controller n the speed loop. The control system s smulated and the results are 4. Error analyss From above fgures, we can see that tradtonal PID has large error n the process of openng and closng operaton, especally n the closng stage, whch has maxmum error. Sngle neuron PID tracks better n early perod of openng and closng operaton and low fluctuatons of error curve n the process of openng and closng operaton, especally the closng operaton velocty trackng curve and the gven curves almost concde. Therefore, the sngle neuron PID controller has hgh stablty and good trackng performance, and t s an deal choce for the servo system smulaton analyss of the hgh voltage 8

5 crcut breaker brushless DC motor operatng mechansm control system. 5 CONCLUSION By analyzng the smulaton results of hgh voltage crcut breaker motor operaton mechansm control system, t proves that the fuzzy adaptve PID controller n the realzaton of hgh voltage crcut breaker brushless DC motor operatng mechansm velocty trackng smulaton has good response characterstc and hgh trackng accuracy, whch s the deal choce for speed trackng control system. The research results of ths paper provde references for the motor operaton mechansm movement control and velocty trackng ACKNOWLEDGEMENTS Ths work s supported by CCTEG Shenyang Research Insttute scence& technology nnovaton fund (0MS04), (04QN05). REFERENCES LI Yusheng, HAO Fengnan. Sealed pole and pourng technque of vacuum crcut breaker[j]. Electrc Engneerng, 008 ():6-6. LI Janj. Applcaton of sold sealed pole technology nvacuum crcut breaker[j]. Popular Utlzaton of Electrcty, 005 (4):-. ZHANG Hong-te, JIANG Guan-yu, FENG Xang-we. Improvement of a Knd of Sold-Insulaton-Embedded Pole Outlet Lne Structure[J]. Electrotechncs Electrc,, 04 ():5-5. ZHOU Le,PAN Huang.Bref Analyss on Several Prncpal Sold Insulaton Embedded Vacuum Crcut Breakers[J]. East Chna Electrc Power,00(8): YANG We-y, XU Zhong.Techncal Research and Development of Mne Flameproof Hgh voltage Vacuum Dstrbuton Unt [J]. Collery Mechancal & Electrcal Technology, 008 (): ZHOU Ybo,WAN Swe,ZENG Xanwen,LI Shunyao, ZHONG Shje. Cause Analyss of a 0 kv GIS Leakage and Dsc Insulator Breakage[J]. Guangdong Electrc Power, 0 (5): 8-. YAO Qang, WANG Yong,LIU Yong.The Applcaton of Impurty Analyss of SF6 for Fault Dagnoss of GIS[J].Hgh Voltage Appratus,00,46(5):5-8. ZOU J-yan,DUAN Xong-yng,LUO Yan.Onlne Montorng System of Intellgent Vacuum Crcut Breakers[J]. 00 ():-4. 8