基于随机载荷功率谱的电动拖拉机复合能量系统研究
|
摘要
拖拉机重载作业模式下负载峰值功率和高频功率存在较大随机性,单一电源方案无法有效匹配电动拖拉机负载特性。通过分析拖拉机工况负载势变量功率谱密度和电源放电特性,基于电动拖拉机通过主、辅电源对低、高频功率分流的观点,设计了采用DC-DC转换器并联超级电容器的18.5 k W电动拖拉机复合电源方案,计算了系统参数。以平衡峰值功率和高频载荷控制超级电容器功率流方向为目标,设计了基于逻辑门的双DC-DC模式控制策略。根据负载时频分析需求,构建了基于Haar小波的双通道滤波器组,设计了功率分配控制器。以标准正态分布白噪声为基波,构造拖拉机犁耕、旋耕载荷波动间的互谱函数,建立了负载模拟模块。采用CRUISE/Simulink API动态联合仿真得出:基于功率分配控制的能量管理策略能够将动力电池电功率抑制在载荷波动基频附近,犁耕作业和旋耕作业下其电功率的截止频率分别为2、7 Hz,幅值符合正偏态分布;超级电容器平衡高频载荷,其电功率符合标准正态分布。
When electric tractor working on heavy load model,such as plowing and rotary tillage,the peak power with high frequency of the working condition has more randomness. Energy systems of the electric tractor,which consists of single type of electric power source,e. g. batteries,may not effectively match the required power of dynamic load characteristic. Aimed at these problems,the electric tractor energy system and the management strategy were researched by the way based on the power spectral density of tractor load. By the analyses of electric drive train power flow,power spectral density of potential flow variables of tractor load and frequency characteristic in discharge process of common electric source,the feasibility of the way to separate the power flows with low frequency and high frequency via synergic electric power supply system was discussed. By mathematically building the constraint modelling of the endurance performance,power property,maximum using weight of tractor,steady and dynamic characteristic of load,the design method of energy systems with synergic electric power supply system in electric tractor was proposed. After that,the 18. 5 k W electric tractor energy system which was assembled by the parallel connection between batteries and super capacitors via DC-DC converter was designed. For the elimination of peak power with high frequency of battery and the direction control of the super capacitor power flow,the double DC-DC converter control strategy based on logic control was generated. For the requirement of time-frequency analysis,the power distribution controller ofthe management strategy was designed by using two-channel filter bank with Haar wavelet. By constructing the mutual spectral density function between Gaussian white noise and working load of the tractor on plowing and rotary tillage,the load-time wave used in the simulation was established. The simulation ran on the platform that the simulation model of tractor plowing and rotary tillage unit built on AVL CRUISE dynamically combined with the management strategy simulation model on Matlab/Simulink.And it can be found that the management strategy based on power spectral density can limit the frequency of the power flow transiting electric power the batteries of synergic electric power supply system on the fundamental frequency of working load. Under the plowing condition,the frequency of battery electric power was cut off at 2 Hz. And under the rotary tillage condition,the frequency of battery electric power was cut off at 7 Hz. The amplitudes of electric power flow conformed to positive skew distribution. The remainder of required power was provided by super capacitance. And the amplitudes of remaining electric power flow accorded with standard normal distribution. The research proposed can offer theory reference and technology support to other researchers whose working field would be related to electric tractor and energy management.
When electric tractor working on heavy load model,such as plowing and rotary tillage,the peak power with high frequency of the working condition has more randomness. Energy systems of the electric tractor,which consists of single type of electric power source,e. g. batteries,may not effectively match the required power of dynamic load characteristic. Aimed at these problems,the electric tractor energy system and the management strategy were researched by the way based on the power spectral density of tractor load. By the analyses of electric drive train power flow,power spectral density of potential flow variables of tractor load and frequency characteristic in discharge process of common electric source,the feasibility of the way to separate the power flows with low frequency and high frequency via synergic electric power supply system was discussed. By mathematically building the constraint modelling of the endurance performance,power property,maximum using weight of tractor,steady and dynamic characteristic of load,the design method of energy systems with synergic electric power supply system in electric tractor was proposed. After that,the 18. 5 k W electric tractor energy system which was assembled by the parallel connection between batteries and super capacitors via DC-DC converter was designed. For the elimination of peak power with high frequency of battery and the direction control of the super capacitor power flow,the double DC-DC converter control strategy based on logic control was generated. For the requirement of time-frequency analysis,the power distribution controller ofthe management strategy was designed by using two-channel filter bank with Haar wavelet. By constructing the mutual spectral density function between Gaussian white noise and working load of the tractor on plowing and rotary tillage,the load-time wave used in the simulation was established. The simulation ran on the platform that the simulation model of tractor plowing and rotary tillage unit built on AVL CRUISE dynamically combined with the management strategy simulation model on Matlab/Simulink.And it can be found that the management strategy based on power spectral density can limit the frequency of the power flow transiting electric power the batteries of synergic electric power supply system on the fundamental frequency of working load. Under the plowing condition,the frequency of battery electric power was cut off at 2 Hz. And under the rotary tillage condition,the frequency of battery electric power was cut off at 7 Hz. The amplitudes of electric power flow conformed to positive skew distribution. The remainder of required power was provided by super capacitance. And the amplitudes of remaining electric power flow accorded with standard normal distribution. The research proposed can offer theory reference and technology support to other researchers whose working field would be related to electric tractor and energy management.
引文
1谢斌,张超,陈硕,等.双轮驱动电动拖拉机传动性能研究[J/OL].农业机械学报,2015,46(6):8-13.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20150602&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2015.06.002.XIE Bin,ZHANG Chao,CHEN Shuo,et al.Transmission performance of two-wheel drive electric tractor[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2015,46(6):8-13.(in Chinese)
2 DAVIES D B,FINNEY J B,RICHARDSON S J.Relative effects of tractor weight and wheel-slip in causing soil compaction[J].Journal of Soil Science,1973,24(3):399-409.
3 WONG J Y.Terramechanics and off-road vehicle engineering:terrain behaviour,off-road vehicle performance and design[M].2nd ed.Oxford:Elsevier Ltd,2010:129-149.
4陈秉聪,秦维谦,张兰义,等.农具机组负载模拟器[J].吉林工业大学学报,1991(4):34-40.CHEN Bingcong,QIN Weiqian,ZHANG Lanyi,et al.Load simulator of tractor-implement combination[J].Journal of Jilin University of Technology,1991(4):34-40.(in Chinese)
5葛智元,周立新,赵巍,等.超级电容器与蓄电池并联混合电源放电特性[J].电源技术,2014,38(5):886-913.GE Zhiyuan,ZHOU Lixin,ZHAO Wei,et al.Discharging performance of hybrid power of supercapacitor in parallel with lead acid battery[J].Chinese Journal of Power Sources,2014,38(5):886-913.(in Chinese)
6 SIKHA G,NPOPOV B.Performance optimization of a battery-capacitor hybrid system[J].Journal of Power Sources,2004,134(1):130-138.
7 ZHANG X,MI C,MASRUR A,et al.Wavelet-transform-based power management of hybrid vehicles with multiple on-board energy sources including fuel cell,battery and ultracapacitor[J].Journal of Power Sources,2008,185(2):1533-1543.
8石庆升,张承慧,崔纳新.新型双能量源纯电动汽车能量管理问题的优化控制[J].电工技术学报,2008,23(8):137-142.SHI Qingsheng,ZHANG Chenghui,CUI Naxin.Optimal control of energy management in novel electric vehicle with dual-source energy storage system[J].Transactions of China Electrotechnical Society,2008,23(8):137-142.(in Chinese)
9胡瑾瑜,宋珂,章桐.基于神经网络的增程式电动汽车能量管理策略研究[J].佳木斯大学学报:自然科学版,2011,29(6):829-832.HU Jinyu,SONG Ke,ZHANG Tong.Study on the energy management policy of extended-range electric vehicle based on neutral network[J].Journal of Jiamusi University:Natural Science Edition,2011,29(6):829-832.(in Chinese)
10 FLORENTSEV S,IZOSIMOV D,MAKAROV L,et al.Complete traction electric equipment sets of electro-mechanical drive trains for tractors[C]∥Proceedings of 2010 IEEE Region 8 International Conference on Computational Technologies in Electrical and Electronics Engineering,2010:611-616.
11 CARLINI M,ABENAVOLI R I,KORMANSKI H,et al.A hybrid electric propulsion system for a forest vehicle[C]∥Proceedings of the 32nd Intersociety Energy Conversion Engineering Conference 1997,1997:2019-2023.
12冯锡曙,郑松林,李国英,等.拖拉机载荷二维概率分布模型及其工程应用[J].拖拉机,1992(3):10-24.FENG Xishu,ZHENG Songlin,LI Guoying,et al.The two-dimension model and application of load probability distribution of tractor[J].Tractor,1992(3):10-24.(in Chinese)
13方在华,周志立,杨铁皂,等.拖拉机随机载荷的功率谱函数[J].洛阳工学院学报,1999,20(4):1-4.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.The power spectral function of the random loads in tractor[J].Journal of Luoyang Institute of Technology,1999,20(4):1-4.(in Chinese)
14赵波,牛毅,周志立,等.拖拉机旋耕机组载荷随机特性的实验[J].洛阳工学院学报,1995,16(1):69-74.ZHAO Bo,NIU Yi,ZHOU Zhili,et al.Experiment on the statistical characteristic of loads for rotocultivator and tractor unit[J].Journal of Luoyang Institute of Technology,1995,16(1):69-74.(in Chinese)
15方在华,周志立,杨铁皂,等.犁耕和旋耕作业发动机载荷的统计特性[J].农业工程学报,2000,16(4):85-87.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.Statistical properties of working load of engine in plowing and rototilling[J].Transactions of CSAE,2000,16(4):85-87.(in Chinese)
16方在华,周志立,杨铁皂,等.正态随机载荷的计算机仿真[J].洛阳工学院学报,2000,21(1):1-3.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.Computer simulation for normal random load[J].Journal of Luoyang Institute of Technology,2000,21(1):1-3.(in Chinese)
17韩智强,姜久春,孙丙香,等.锂离子动力电池电路模型的频率特性分析[J].电源技术,2015,39(2):268-272.HAN Zhiqiang,QIN Jiuchun,SUN Bingxiang,et al.Frequency characteristics analysis of lithium-ion power battery circuit model[J].Chinese Journal of Power Sources,2015,39(2):268-272.(in Chinese)
18 JOSSEN A.Fundamentals of battery dynamics[J].Journal of Power Sources,2006,154(2):530-538.
19 BOGGESS A,NARCOWICH F J.A first course in wavelets with Fourier analysis[M].2nd ed.New York:John Wiley&Sons,2010:121-207.
20章步云,周书民.非平稳信号的快速傅里叶变换与小波分析的比较[J].通信技术,2002(7):1-2.ZHANG Buyun,ZHOU Shumin.The difference of between analyzing by fast Fourier translation and analyzing by wavelet[J].Communications Technology,2002(7):1-2.(in Chinese)
21 ZHANG X,MI C.Vehicle power management:modelling,control and optimization[M].London:Spring,2011:124-126.
22刘孟楠,徐立友,周志立,等.增程式电动拖拉机及其旋耕机组仿真平台开发[J].中国机械工程,2016,27(3):413-419.LIU Mengnan,XU Liyou,ZHOU Zhili,et al.Establishment of extended range electric tractor and its rotary cultivator’s simulative platforms[J].China Mechanical Engineering,2016,27(3):413-419.(in Chinese)
2 DAVIES D B,FINNEY J B,RICHARDSON S J.Relative effects of tractor weight and wheel-slip in causing soil compaction[J].Journal of Soil Science,1973,24(3):399-409.
3 WONG J Y.Terramechanics and off-road vehicle engineering:terrain behaviour,off-road vehicle performance and design[M].2nd ed.Oxford:Elsevier Ltd,2010:129-149.
4陈秉聪,秦维谦,张兰义,等.农具机组负载模拟器[J].吉林工业大学学报,1991(4):34-40.CHEN Bingcong,QIN Weiqian,ZHANG Lanyi,et al.Load simulator of tractor-implement combination[J].Journal of Jilin University of Technology,1991(4):34-40.(in Chinese)
5葛智元,周立新,赵巍,等.超级电容器与蓄电池并联混合电源放电特性[J].电源技术,2014,38(5):886-913.GE Zhiyuan,ZHOU Lixin,ZHAO Wei,et al.Discharging performance of hybrid power of supercapacitor in parallel with lead acid battery[J].Chinese Journal of Power Sources,2014,38(5):886-913.(in Chinese)
6 SIKHA G,NPOPOV B.Performance optimization of a battery-capacitor hybrid system[J].Journal of Power Sources,2004,134(1):130-138.
7 ZHANG X,MI C,MASRUR A,et al.Wavelet-transform-based power management of hybrid vehicles with multiple on-board energy sources including fuel cell,battery and ultracapacitor[J].Journal of Power Sources,2008,185(2):1533-1543.
8石庆升,张承慧,崔纳新.新型双能量源纯电动汽车能量管理问题的优化控制[J].电工技术学报,2008,23(8):137-142.SHI Qingsheng,ZHANG Chenghui,CUI Naxin.Optimal control of energy management in novel electric vehicle with dual-source energy storage system[J].Transactions of China Electrotechnical Society,2008,23(8):137-142.(in Chinese)
9胡瑾瑜,宋珂,章桐.基于神经网络的增程式电动汽车能量管理策略研究[J].佳木斯大学学报:自然科学版,2011,29(6):829-832.HU Jinyu,SONG Ke,ZHANG Tong.Study on the energy management policy of extended-range electric vehicle based on neutral network[J].Journal of Jiamusi University:Natural Science Edition,2011,29(6):829-832.(in Chinese)
10 FLORENTSEV S,IZOSIMOV D,MAKAROV L,et al.Complete traction electric equipment sets of electro-mechanical drive trains for tractors[C]∥Proceedings of 2010 IEEE Region 8 International Conference on Computational Technologies in Electrical and Electronics Engineering,2010:611-616.
11 CARLINI M,ABENAVOLI R I,KORMANSKI H,et al.A hybrid electric propulsion system for a forest vehicle[C]∥Proceedings of the 32nd Intersociety Energy Conversion Engineering Conference 1997,1997:2019-2023.
12冯锡曙,郑松林,李国英,等.拖拉机载荷二维概率分布模型及其工程应用[J].拖拉机,1992(3):10-24.FENG Xishu,ZHENG Songlin,LI Guoying,et al.The two-dimension model and application of load probability distribution of tractor[J].Tractor,1992(3):10-24.(in Chinese)
13方在华,周志立,杨铁皂,等.拖拉机随机载荷的功率谱函数[J].洛阳工学院学报,1999,20(4):1-4.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.The power spectral function of the random loads in tractor[J].Journal of Luoyang Institute of Technology,1999,20(4):1-4.(in Chinese)
14赵波,牛毅,周志立,等.拖拉机旋耕机组载荷随机特性的实验[J].洛阳工学院学报,1995,16(1):69-74.ZHAO Bo,NIU Yi,ZHOU Zhili,et al.Experiment on the statistical characteristic of loads for rotocultivator and tractor unit[J].Journal of Luoyang Institute of Technology,1995,16(1):69-74.(in Chinese)
15方在华,周志立,杨铁皂,等.犁耕和旋耕作业发动机载荷的统计特性[J].农业工程学报,2000,16(4):85-87.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.Statistical properties of working load of engine in plowing and rototilling[J].Transactions of CSAE,2000,16(4):85-87.(in Chinese)
16方在华,周志立,杨铁皂,等.正态随机载荷的计算机仿真[J].洛阳工学院学报,2000,21(1):1-3.FANG Zaihua,ZHOU Zhili,YANG Tiezao,et al.Computer simulation for normal random load[J].Journal of Luoyang Institute of Technology,2000,21(1):1-3.(in Chinese)
17韩智强,姜久春,孙丙香,等.锂离子动力电池电路模型的频率特性分析[J].电源技术,2015,39(2):268-272.HAN Zhiqiang,QIN Jiuchun,SUN Bingxiang,et al.Frequency characteristics analysis of lithium-ion power battery circuit model[J].Chinese Journal of Power Sources,2015,39(2):268-272.(in Chinese)
18 JOSSEN A.Fundamentals of battery dynamics[J].Journal of Power Sources,2006,154(2):530-538.
19 BOGGESS A,NARCOWICH F J.A first course in wavelets with Fourier analysis[M].2nd ed.New York:John Wiley&Sons,2010:121-207.
20章步云,周书民.非平稳信号的快速傅里叶变换与小波分析的比较[J].通信技术,2002(7):1-2.ZHANG Buyun,ZHOU Shumin.The difference of between analyzing by fast Fourier translation and analyzing by wavelet[J].Communications Technology,2002(7):1-2.(in Chinese)
21 ZHANG X,MI C.Vehicle power management:modelling,control and optimization[M].London:Spring,2011:124-126.
22刘孟楠,徐立友,周志立,等.增程式电动拖拉机及其旋耕机组仿真平台开发[J].中国机械工程,2016,27(3):413-419.LIU Mengnan,XU Liyou,ZHOU Zhili,et al.Establishment of extended range electric tractor and its rotary cultivator’s simulative platforms[J].China Mechanical Engineering,2016,27(3):413-419.(in Chinese)