自控变频式同步电动机锁相并网技术研究
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摘要
作为钢铁、冶金、采矿、水利等行业生产中的关键设备,高压大功率同步电动机由于其转矩和功率因数可调,对电网波动不敏感,效率高的优点,广泛用于拖动大型鼓风机、水泵、压缩机等负载。随着电力电子变换技术和微控制器技术的发展,现普遍认为自控变频起动是高压大功率同步电机的最佳起动方式。本文针对自控变频式同步电动机无冲击并网这一技术难点,进行了较为深入的分析和研究,提出了基于全数字锁相环的调频锁相方法和基于励磁电流闭环控制的调压策略。
首先,对自控变频式同步电机无冲击并网原理进行了理论分析,结合无冲击并网应遵循的三个基本条件,详细描述了并网过程中的控制方法。在并网前,采用断续换流法起动,在电机转速升至额定转速的8%后,切换至负载换流法直到将同步电动机拉至同步转速附近。当转速达到95%额定转速时即可认为进入并网过程。
其次,为实现励磁电流的闭环控制,设计了一套并网硬件平台,包括电网侧和电机侧电压幅值、过零点检测调理电路,励磁电流检测及调节电路以及与主控制器通讯电路。根据维持直流母线电流连续及抑制直流母线电流波动两方面的要求选取了直流平波电抗器的电感值。起动时根据负载需求,给定并保持恒定的励磁电流,进入并网过程后闭环控制励磁电流,使电机反电势跟踪电网电压,具有很高的稳态精度。
最后,提出了采用检测电网线电压和电机反电势过零点鉴相、锁相环与带死区的速度环协同调节的双模控制方式。从根本上解决了锁相捕捉频率带宽窄,容易失锁的问题,具有暂态过程平稳,稳态无静差的特点。
在实验样机环境下,以额定参数为3kW/380V/1500r/min同步电机为控制对象进行实验,并网控制阶段末期,同步电机定子端电压与电网电压的频率差小于0.25Hz,电压差小于电机额定电压5%,相位差几乎为零,完全满足工程中无冲击并网条件。
As the key equipment in iron and steel enterprises, metallurgy, mining or hydro-electric industries, high-voltage and high-power synchronous motor was generally used to drive large blowers, pumps, compressors, for its advantage of adjustable torque and power factor, being insensitive to grid fluctuation and very high efficiency. It is commonly considered that the self-controlled soft-start method is the best mode to start this kind of motors. To solve the difficulty of electrical grid connection technology without impact, in this paper, analysis and research are presented. It gives digital Phase-Locked-Loop to adjust motor frequency and phase, and closed-loop excitation plot to regulate Back-EMF.
In the beginning of this paper, it derived from some basic mathematical relationships and working principles of this technology. Combined with three conditions, holistic approach of entire process of grid-connection was introduced. When the start process begins, under 8% of rated speed of the motor, break commutate mode is adapted. At medium and high speed, zero-crossing detection of Back-EMF is used until it approximately rises to the synchronous speed, almost the 95% of rated speed. After that, grid-connection segment activates.
Secondly, to implement the closed-loop control of excitation current, a series of circuits is designed to acquire grid voltage, Back-EMF and their zero-crossing points, also to adjust excitation current and communicate with main controller. Smoothing reactor was determined based on DC bus’s continuity and fluctuation condition. When starting, excitation current will be able to adjust manually and control automatic. The excitation controller has satisfactory steady state precision.
At last, software PLL algorithm applies the zero-crossing-point phase-detector to compute the phase difference of grid and motor. It coordinates with speed-loop and electricity-loop and has solved PLL’s narrow bandwidth problem. The PLL algorithm has smooth steady state and has no static error.
A 3kW/380V/1500r/min synchronous motor is used as control plant in the experiment platform. At the end of grid-connection process, the difference of grid voltage and Back-EMF meets the following conditions: frequency difference less than 0.25Hz; voltage difference less than 5% EMF; phase difference approaches to zero. It is a very satisfactory result to realize grid-connection without impact.
首先,对自控变频式同步电机无冲击并网原理进行了理论分析,结合无冲击并网应遵循的三个基本条件,详细描述了并网过程中的控制方法。在并网前,采用断续换流法起动,在电机转速升至额定转速的8%后,切换至负载换流法直到将同步电动机拉至同步转速附近。当转速达到95%额定转速时即可认为进入并网过程。
其次,为实现励磁电流的闭环控制,设计了一套并网硬件平台,包括电网侧和电机侧电压幅值、过零点检测调理电路,励磁电流检测及调节电路以及与主控制器通讯电路。根据维持直流母线电流连续及抑制直流母线电流波动两方面的要求选取了直流平波电抗器的电感值。起动时根据负载需求,给定并保持恒定的励磁电流,进入并网过程后闭环控制励磁电流,使电机反电势跟踪电网电压,具有很高的稳态精度。
最后,提出了采用检测电网线电压和电机反电势过零点鉴相、锁相环与带死区的速度环协同调节的双模控制方式。从根本上解决了锁相捕捉频率带宽窄,容易失锁的问题,具有暂态过程平稳,稳态无静差的特点。
在实验样机环境下,以额定参数为3kW/380V/1500r/min同步电机为控制对象进行实验,并网控制阶段末期,同步电机定子端电压与电网电压的频率差小于0.25Hz,电压差小于电机额定电压5%,相位差几乎为零,完全满足工程中无冲击并网条件。
As the key equipment in iron and steel enterprises, metallurgy, mining or hydro-electric industries, high-voltage and high-power synchronous motor was generally used to drive large blowers, pumps, compressors, for its advantage of adjustable torque and power factor, being insensitive to grid fluctuation and very high efficiency. It is commonly considered that the self-controlled soft-start method is the best mode to start this kind of motors. To solve the difficulty of electrical grid connection technology without impact, in this paper, analysis and research are presented. It gives digital Phase-Locked-Loop to adjust motor frequency and phase, and closed-loop excitation plot to regulate Back-EMF.
In the beginning of this paper, it derived from some basic mathematical relationships and working principles of this technology. Combined with three conditions, holistic approach of entire process of grid-connection was introduced. When the start process begins, under 8% of rated speed of the motor, break commutate mode is adapted. At medium and high speed, zero-crossing detection of Back-EMF is used until it approximately rises to the synchronous speed, almost the 95% of rated speed. After that, grid-connection segment activates.
Secondly, to implement the closed-loop control of excitation current, a series of circuits is designed to acquire grid voltage, Back-EMF and their zero-crossing points, also to adjust excitation current and communicate with main controller. Smoothing reactor was determined based on DC bus’s continuity and fluctuation condition. When starting, excitation current will be able to adjust manually and control automatic. The excitation controller has satisfactory steady state precision.
At last, software PLL algorithm applies the zero-crossing-point phase-detector to compute the phase difference of grid and motor. It coordinates with speed-loop and electricity-loop and has solved PLL’s narrow bandwidth problem. The PLL algorithm has smooth steady state and has no static error.
A 3kW/380V/1500r/min synchronous motor is used as control plant in the experiment platform. At the end of grid-connection process, the difference of grid voltage and Back-EMF meets the following conditions: frequency difference less than 0.25Hz; voltage difference less than 5% EMF; phase difference approaches to zero. It is a very satisfactory result to realize grid-connection without impact.
引文
1张兆龙.电机节能新突破:自适应随动控制技术简介.资源节约与环保. 2002, (2):26~27
2余元旗.相控节电技术及其应用.大众用电. 2004, (3):16~17
3 Cheng-Ting Hsu, Hui-Jen Chuang, Chao-Shun Chen. Power Quality Assessment of Large Motor Starting and Loading for the Integrated Steel-Making Cogeneration Facility. IEEE Transaction on Industry Applications. 2007, 43(2):395~402
4刘铁成.国产高压变频器在炼铁厂除尘风机上的改造分析.电工技术杂志. 2004, (9):21~25
5汤蕴璆,史乃.电机学.机械工业出版社, 1999:183~185
6王奇峰,陈济良,林佐伟,张超.高压电动机起动方式的设计与探讨.能源工程, 2009, (3):22~25
7王燕永,周永华. 4.8万千瓦同步电动机的可控硅变频起动装置及其在调试中的主要故障分析.宝钢技术, 1985, (2):40~50
8任致程,任国雄.电动机软起动器使用手册.中国电力出版社, 2006:1~2
9马永明.大容量同步电机液态软起动技术.电工技术, 2009, (5):76~77
10 J.Nevelsteen, H.Aragon. Starting of large motors-methods and economics. IEEE Trans. Ind. Application, 1989, 25(6):1012~1018
11阎世强,宋艳敏,彭自力.液态变阻软起动装置在大型同步电机中的应用.电气技术, 2009, (3):82~84
12陈建国,孙玉鸿,曲安义.高压交流电动机液态软起动技术开发及其应用.电气传动, 2000, (5):56~58
13万山明,吴芳,黄声华.基于高频电压信号注入的永磁同步电机转子初始位置估计.中国电机工程学报, 2008, 28(33):82~86
14 Mohamed B.Implementation and experimental investigation of sensorless speed control with initial rotor position estimation for interior permanent magnet synchronous motor drive. IEEE Transactions on Power Electronics, 2005, 20(6):1413-1422
15杜海江,石新春.无换向器电机全程式转子电气位置检测方法的分析与实现.电工技术学报, 2005, 20(5):80~86
16 Rajib Dutta, Chandan Chakraborty, Sabyasachi Sengupta. Performance of anInverter-Fed Self-Controlled Synchronous Motor with Series Characteristics. Symposium of IEEE Industry Applications Society Annual Meeting. Macao, 1994:424~431
17赵毅,李彦生,赵万华.电机锁相控制系统的分析与设计.微电机. 1997, 30(1):20~23
18欧阳晖.同步发电机励磁系统电压模式下并网策略研究.变频器世界. 2007, (11):42~44
19刘晓东,姜建国.同步发电机与大型交流设备并网运行特性的研究.煤矿设计. 1995, (12):22~25
20王耀明,赵荣祥.永磁同步电动机的起动并网控制研究.微特电机. 1994, (4):14~16
21 Qian Weizhe, Panda S K, Xu Jianxin. Torque ripple minimization in PM synchronous motors using iterative learning control. IEEE Transactions on Power Electronics. 2004, 19(2):272~279
22 L.N.Arruda, S.M.Silva, B.J.C.Filho. PLL structures for utility connected systems. Proceeding of 36th Annual Meeting of IEEE Industrial Application Conference. Chicago, 2001:672~678
23张厥盛,郑继禹,万心平.锁相技术.西安电子科技大学出版社, 1994:3~4
24王福昌,鲁昆生.锁相技术.华中科技大学出版社, 1997:10~11
25窦新华,韦康.模拟锁相环NE564在FM解调电路中的应用.电子技术. 2010, (2):77~78
26 Lee J, Kim B. A Low-noise fast-lock phase-locked loop with adaptive bandwidth control. IEEE Journal of Solid- state Circuits. 2000, 35(8): 1137~1145
27 Jacquot, Raymond G. Modern Digital Control Systems. Marcel Dekker, Inc., 1981:26~28
28 Floyd M. Gardner. Phaselock Techniques. Wiley & Sons, Inc., 2005:8~16
29李志杰,张遇民.同步电动机调速系统.机械工业出版社, 2001:137~141
30喻德忠.无换向器电动机的控制技术.华北电力大学硕士论文. 2001:43~47
31 I. Cadirci, M. Ermis, E. Nalcacl. A Solid State Direct on Line Starter for Medium Voltage Induction Motors with Minimized Current and Torque Pulsations. IEEE Transaction on Energy Conversion. 1999, 14(3):402~412
32 Chihiro Hasegawa, Shoji Nishikata. A Sensorless Rotor Position Detecting Method for Self-Controlled Synchronous Motors. 11th International Conference on Electrical Machines and Systems, Wuhan, 2008:123~128
33 J.J.Nel, D.J.Mulder, G.L.Bredenkamp. A Series Thyristor Switch Driving a Multi-Stage Ferrite Pulse Compressor for Copper-Vapour-Laser Application.IEEE Conference Record of the 19th Power Modulator Symposium, 1990(1):357~360
34赵荣祥,许大中.无位置检测器无换向器电机.电气传动自动化. 1994, 16(3):17~20
35 Hoang Le-huy, Alain Jakubowicz, Robert Perret. A Self-Controlled Synchronous Motor Drive using Terminal Voltage System. IEEE Transaction on Industry Applications. 1982, vol.IA-18(1):46~53
36 Bin Wu.大功率变频器及交流传动.机械工业出版社, 2008:56~64
37徐科军,张瀚,陈智渊. TMS320X281xDSP原理与应用.北京航空航天大学出版社, 2006:3~12
38王忠勇,陈恩庆. DSP原理与应用技术.电子工业出版社, 2009:2~4
39 S.Fukuda, S.Sasaka. Constant Margin-angle Control of Commutatorless Motor Using Microcomputer. IEEE Trans on Industry Applications. 1987, 23(5) :8 55~862
40 Sabyasachi SenGupta et al. Preformance of an SCR-Inverter-Based Commutatorless Series Motor with Load Commutation and Unaided Startup Capability. IEEE Trans on Industry Applications. 2000, 36(4):1151~1157
41 Quan Jiang, Chao Bi, Ruoyu Huang. A New Phase-Delay-Free Method to Detect Back EMF Zero-Crossing Points for Sensorless Control of Spindle Motors. IEEE Transactions on Magnetics. 2005, 41(7):2287~2294
42许大中.晶闸管无换向器电机.科学出版社, 1984:354~377
43杜海江.高压无换向器电机及其控制技术.华北电力大学博士论文. 2005:23~28
44 T. Maeno, M. Kobata. AC Commutatorless and Brushless Motor. IEEE Trans. on Power Systerm Application. 1972, 9(1):1476~1484
45陈伯时.电力拖动自动控制系统—运动控制系统.第3版.机械工业出版社, 2006:56~58
46张国范,顾树生,王明顺.计算机控制系统.冶金工业出版社, 2004:95~96
47 Guanchyun Hsieh, J.C. Hung. Phase-Locked Loop Techniques. A Survey. IEEE Trans Industrial Electronics. 1996, (43):609~615
48方忠.带死区的PID控制算法及其组态仿真.科技信息. 2009, (25):70~72
49 Prodeep B. Deshpande, Raymond H. Ash. Elements of Computer Process with Advanced Control Application. USA Instrument Society Symposium. 1992, (1):228~238
50汤蕴璆,史乃.电机学.机械工业出版社, 1999:216~217
51王耀明.自控式同步电动机高性能控制.清华大学学报(自然科学版). 2003,35(4):55~61
52 Taylor Moore. Custom Power Optimizing Distribution Services. EPRI Journal. 1996, (10):7~15
53 Hoang Le-Huy. Modeling and Simulation of Electrical Drives using MATLAB/Simulink and Power System Blockset. IEEE Proceeding from Industrial Electronics Society. Ste-Foy , 2001:672~678
2余元旗.相控节电技术及其应用.大众用电. 2004, (3):16~17
3 Cheng-Ting Hsu, Hui-Jen Chuang, Chao-Shun Chen. Power Quality Assessment of Large Motor Starting and Loading for the Integrated Steel-Making Cogeneration Facility. IEEE Transaction on Industry Applications. 2007, 43(2):395~402
4刘铁成.国产高压变频器在炼铁厂除尘风机上的改造分析.电工技术杂志. 2004, (9):21~25
5汤蕴璆,史乃.电机学.机械工业出版社, 1999:183~185
6王奇峰,陈济良,林佐伟,张超.高压电动机起动方式的设计与探讨.能源工程, 2009, (3):22~25
7王燕永,周永华. 4.8万千瓦同步电动机的可控硅变频起动装置及其在调试中的主要故障分析.宝钢技术, 1985, (2):40~50
8任致程,任国雄.电动机软起动器使用手册.中国电力出版社, 2006:1~2
9马永明.大容量同步电机液态软起动技术.电工技术, 2009, (5):76~77
10 J.Nevelsteen, H.Aragon. Starting of large motors-methods and economics. IEEE Trans. Ind. Application, 1989, 25(6):1012~1018
11阎世强,宋艳敏,彭自力.液态变阻软起动装置在大型同步电机中的应用.电气技术, 2009, (3):82~84
12陈建国,孙玉鸿,曲安义.高压交流电动机液态软起动技术开发及其应用.电气传动, 2000, (5):56~58
13万山明,吴芳,黄声华.基于高频电压信号注入的永磁同步电机转子初始位置估计.中国电机工程学报, 2008, 28(33):82~86
14 Mohamed B.Implementation and experimental investigation of sensorless speed control with initial rotor position estimation for interior permanent magnet synchronous motor drive. IEEE Transactions on Power Electronics, 2005, 20(6):1413-1422
15杜海江,石新春.无换向器电机全程式转子电气位置检测方法的分析与实现.电工技术学报, 2005, 20(5):80~86
16 Rajib Dutta, Chandan Chakraborty, Sabyasachi Sengupta. Performance of anInverter-Fed Self-Controlled Synchronous Motor with Series Characteristics. Symposium of IEEE Industry Applications Society Annual Meeting. Macao, 1994:424~431
17赵毅,李彦生,赵万华.电机锁相控制系统的分析与设计.微电机. 1997, 30(1):20~23
18欧阳晖.同步发电机励磁系统电压模式下并网策略研究.变频器世界. 2007, (11):42~44
19刘晓东,姜建国.同步发电机与大型交流设备并网运行特性的研究.煤矿设计. 1995, (12):22~25
20王耀明,赵荣祥.永磁同步电动机的起动并网控制研究.微特电机. 1994, (4):14~16
21 Qian Weizhe, Panda S K, Xu Jianxin. Torque ripple minimization in PM synchronous motors using iterative learning control. IEEE Transactions on Power Electronics. 2004, 19(2):272~279
22 L.N.Arruda, S.M.Silva, B.J.C.Filho. PLL structures for utility connected systems. Proceeding of 36th Annual Meeting of IEEE Industrial Application Conference. Chicago, 2001:672~678
23张厥盛,郑继禹,万心平.锁相技术.西安电子科技大学出版社, 1994:3~4
24王福昌,鲁昆生.锁相技术.华中科技大学出版社, 1997:10~11
25窦新华,韦康.模拟锁相环NE564在FM解调电路中的应用.电子技术. 2010, (2):77~78
26 Lee J, Kim B. A Low-noise fast-lock phase-locked loop with adaptive bandwidth control. IEEE Journal of Solid- state Circuits. 2000, 35(8): 1137~1145
27 Jacquot, Raymond G. Modern Digital Control Systems. Marcel Dekker, Inc., 1981:26~28
28 Floyd M. Gardner. Phaselock Techniques. Wiley & Sons, Inc., 2005:8~16
29李志杰,张遇民.同步电动机调速系统.机械工业出版社, 2001:137~141
30喻德忠.无换向器电动机的控制技术.华北电力大学硕士论文. 2001:43~47
31 I. Cadirci, M. Ermis, E. Nalcacl. A Solid State Direct on Line Starter for Medium Voltage Induction Motors with Minimized Current and Torque Pulsations. IEEE Transaction on Energy Conversion. 1999, 14(3):402~412
32 Chihiro Hasegawa, Shoji Nishikata. A Sensorless Rotor Position Detecting Method for Self-Controlled Synchronous Motors. 11th International Conference on Electrical Machines and Systems, Wuhan, 2008:123~128
33 J.J.Nel, D.J.Mulder, G.L.Bredenkamp. A Series Thyristor Switch Driving a Multi-Stage Ferrite Pulse Compressor for Copper-Vapour-Laser Application.IEEE Conference Record of the 19th Power Modulator Symposium, 1990(1):357~360
34赵荣祥,许大中.无位置检测器无换向器电机.电气传动自动化. 1994, 16(3):17~20
35 Hoang Le-huy, Alain Jakubowicz, Robert Perret. A Self-Controlled Synchronous Motor Drive using Terminal Voltage System. IEEE Transaction on Industry Applications. 1982, vol.IA-18(1):46~53
36 Bin Wu.大功率变频器及交流传动.机械工业出版社, 2008:56~64
37徐科军,张瀚,陈智渊. TMS320X281xDSP原理与应用.北京航空航天大学出版社, 2006:3~12
38王忠勇,陈恩庆. DSP原理与应用技术.电子工业出版社, 2009:2~4
39 S.Fukuda, S.Sasaka. Constant Margin-angle Control of Commutatorless Motor Using Microcomputer. IEEE Trans on Industry Applications. 1987, 23(5) :8 55~862
40 Sabyasachi SenGupta et al. Preformance of an SCR-Inverter-Based Commutatorless Series Motor with Load Commutation and Unaided Startup Capability. IEEE Trans on Industry Applications. 2000, 36(4):1151~1157
41 Quan Jiang, Chao Bi, Ruoyu Huang. A New Phase-Delay-Free Method to Detect Back EMF Zero-Crossing Points for Sensorless Control of Spindle Motors. IEEE Transactions on Magnetics. 2005, 41(7):2287~2294
42许大中.晶闸管无换向器电机.科学出版社, 1984:354~377
43杜海江.高压无换向器电机及其控制技术.华北电力大学博士论文. 2005:23~28
44 T. Maeno, M. Kobata. AC Commutatorless and Brushless Motor. IEEE Trans. on Power Systerm Application. 1972, 9(1):1476~1484
45陈伯时.电力拖动自动控制系统—运动控制系统.第3版.机械工业出版社, 2006:56~58
46张国范,顾树生,王明顺.计算机控制系统.冶金工业出版社, 2004:95~96
47 Guanchyun Hsieh, J.C. Hung. Phase-Locked Loop Techniques. A Survey. IEEE Trans Industrial Electronics. 1996, (43):609~615
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