降压型开关液压源工作稳定性及其节能研究
摘要
多执行器特性是液压系统的一大特点。在大功率的工作系统中，提高液压系统的效率对于节能和节约成本是很重要的。目前的多执行器系统主要有：节流调速系统，负载敏感系统，二次调节系统，但均存在各种缺陷。
本世纪初提出的开关液压源系统可以实现在升压及降压过程中增加流量的需要，因而可以很好的适应负载的要求，是一种全新原理的节能型液压系统。作为一种压力转换装置，开关液压源可以很好地适应负载。
本文首先针对降压型开关液压源工作的稳定性问题，提出在降压型开关液压源中引入回油背压，避免系统中出现气蚀现象，提高系统工作的稳定性；其次分析带回油背压的降压型开关液压源的能耗组成，通过仿真与试验，研究负载、开关频率以及系统效率三者之间的关系；最终提出降压增流型开关液压源回油背压控制策略及其工程实现方案，达到最佳节能效果。
第一章综述在液压传动与控制系统中，具有负载适应能力的各种控制回路：压力适应回路、流量适应回路和功率适应回路，以及这些系统的优缺点；介绍新近提出的开关液压源概念及存在的问题。
第二章针对降压型开关液压源存在的气蚀现象，在降压型开关液压源结构中引入背压阀，提高系统工作的稳定性，分析带回油背压的降压增流刑开关液压源的工作原理，并对带回油背压的降压型开关液压源结构中各个元件进行建模，分析系统的动态特性。
第三章主要分析带回油背压的降压型开关液压源的能耗组成，研究背压，负载以及开关频率对系统效率的影响效果，通过仿真及试验，重点分析开关频率对带回油背压的降压型开关液压源效率的影响。
第四章根据能耗分析，针对带回油背压的降压型开关液压源的能耗特性，确定系统能耗的目标函数，通过优化背压以及开关频率这三个参数以使目标函数最小。
第五章总结全文
A practical advantage of hydraulic systems is their multiple-actuator characteristic. At present, there are three kinds of multiple-actuators hydraulic systems: throttle control system, load sensing system and secondary regulation system. But there is disadvantage in each system.
The switchmode hydraulic power supply, which was put forward recently, can realize the adaptation to the load of every actuator, by adjusting the supplied pressure. Through the control of PWM signal, the switchmode hydraulic power supply can output proper pressure, which is adaptive to the load. As a new theory, there are still some problems of switchmode hydraulic power supply. Switchmode hydraulic power supply can adapt to the load, but in the course of pressure buck and pressure boost, the efficiency still needs to be improved. And there is cavitation in the pressure buck switchmode hydraulic power supply.
At first, this article solves the problem of the stability in the pressure buck switchmode hydraulic power supply, through introducing the return pressure into the pressure buck switchmode hydraulic power supply. Secondly, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed, and it researches the relation between the frequency of the switch and the efficiency of the system, through the simulation and the; experiment. Finally, we put forward the control policy of the switch frequency and the return pressure, in order to get the optimal efficiency of the system.
In chapter 1, the article summarizes all kinds of hydraulic systems, which can adapt the load, and the shortcoming of these systems. Next, the conception
of switchmode hydraulic power supply and the limitation of this system are introduced.
In chapter 2, aiming at the cavitation in the pressure buck switchmode hydraulic power supply, the relief valve is introduced in order to improve the stability of this system. In this chapter, the principle of the pressure buck switchmode hydraulic power supply with return pressure is also illuminated, and each component's mathematical modeling is built in order to analyze the dynamic characteristic.
In chapter 3, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed. And we lay emphasis on analyzing the influence of switch frequency to the efficiency.
In chapter 4, on the basis of the constitute of energy loss, the objective of energy loss is established. We minimize the objective, through optimizing the return pressure and switch frequency.
In chapter 5, conclusion.
本世纪初提出的开关液压源系统可以实现在升压及降压过程中增加流量的需要，因而可以很好的适应负载的要求，是一种全新原理的节能型液压系统。作为一种压力转换装置，开关液压源可以很好地适应负载。
本文首先针对降压型开关液压源工作的稳定性问题，提出在降压型开关液压源中引入回油背压，避免系统中出现气蚀现象，提高系统工作的稳定性；其次分析带回油背压的降压型开关液压源的能耗组成，通过仿真与试验，研究负载、开关频率以及系统效率三者之间的关系；最终提出降压增流型开关液压源回油背压控制策略及其工程实现方案，达到最佳节能效果。
第一章综述在液压传动与控制系统中，具有负载适应能力的各种控制回路：压力适应回路、流量适应回路和功率适应回路，以及这些系统的优缺点；介绍新近提出的开关液压源概念及存在的问题。
第二章针对降压型开关液压源存在的气蚀现象，在降压型开关液压源结构中引入背压阀，提高系统工作的稳定性，分析带回油背压的降压增流刑开关液压源的工作原理，并对带回油背压的降压型开关液压源结构中各个元件进行建模，分析系统的动态特性。
第三章主要分析带回油背压的降压型开关液压源的能耗组成，研究背压，负载以及开关频率对系统效率的影响效果，通过仿真及试验，重点分析开关频率对带回油背压的降压型开关液压源效率的影响。
第四章根据能耗分析，针对带回油背压的降压型开关液压源的能耗特性，确定系统能耗的目标函数，通过优化背压以及开关频率这三个参数以使目标函数最小。
第五章总结全文
A practical advantage of hydraulic systems is their multiple-actuator characteristic. At present, there are three kinds of multiple-actuators hydraulic systems: throttle control system, load sensing system and secondary regulation system. But there is disadvantage in each system.
The switchmode hydraulic power supply, which was put forward recently, can realize the adaptation to the load of every actuator, by adjusting the supplied pressure. Through the control of PWM signal, the switchmode hydraulic power supply can output proper pressure, which is adaptive to the load. As a new theory, there are still some problems of switchmode hydraulic power supply. Switchmode hydraulic power supply can adapt to the load, but in the course of pressure buck and pressure boost, the efficiency still needs to be improved. And there is cavitation in the pressure buck switchmode hydraulic power supply.
At first, this article solves the problem of the stability in the pressure buck switchmode hydraulic power supply, through introducing the return pressure into the pressure buck switchmode hydraulic power supply. Secondly, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed, and it researches the relation between the frequency of the switch and the efficiency of the system, through the simulation and the; experiment. Finally, we put forward the control policy of the switch frequency and the return pressure, in order to get the optimal efficiency of the system.
In chapter 1, the article summarizes all kinds of hydraulic systems, which can adapt the load, and the shortcoming of these systems. Next, the conception
of switchmode hydraulic power supply and the limitation of this system are introduced.
In chapter 2, aiming at the cavitation in the pressure buck switchmode hydraulic power supply, the relief valve is introduced in order to improve the stability of this system. In this chapter, the principle of the pressure buck switchmode hydraulic power supply with return pressure is also illuminated, and each component's mathematical modeling is built in order to analyze the dynamic characteristic.
In chapter 3, constitute of the energy loss, in the pressure buck switchmode hydraulic power supply with the return pressure, is analyzed. And we lay emphasis on analyzing the influence of switch frequency to the efficiency.
In chapter 4, on the basis of the constitute of energy loss, the objective of energy loss is established. We minimize the objective, through optimizing the return pressure and switch frequency.
In chapter 5, conclusion.
引文
[1]．路甬祥主编．液压气动技术手册．北京：机械工业出版社，2001
[2]．吴根茂，邱敏秀，王庆丰等主编．实用电液比例技术．杭州：浙江大学出版社，1993
[3]．张占松，蔡宣三等主编．开关电源的原理与设计．北京：电子工业出版社，1998
[4]．王懋瑶主编．液压传动与控制教程．天津：天津大学出版社，1987
[5]．严金坤，张培生主编．液压传动．北京：国防工业出版社，1979
[6]．雷天觉．新编液压工程手册．北京：北京理工大学出版社，1998
[7]．缪维平．浅谈液压系统的节能设计．液压与气动，1999，5
[8]．金春花．液压系统效率的分析与对策．液压与气动，1999，5
[9]．赵健．降低液压系统能耗的有效途径．液压与气动，2000，5
[10]．刘宇辉．二次调节静液传动技术的发展及应用．佳木斯大学学报，2001，1
[11]．顾临怡．多执行器负载敏感系统的分流控制发展综述．机床与液压，2000，3
[12]．黄昕．液压系统的节能措施．贵州工业大学学报，2001，4
[13]．李流远．油液含气量对液压系统的影响．液压与气动，2001，1
[14]．谢卓伟．二次调节静液驱动系统的微机数字闭环控制．工程机械，1990．11
[15]．田联房，于慈远．次级调节液压加载试验台的模糊控制器设计．机床与液压，1998，1
[16]．万汉驰．一种多功能阀在轴向柱塞变量泵与定量马达闭式系统中的
应用．建筑机械，1996，11
[17]．贾文沛．二次规矩调节系统的实验研究．太原重型机械学院学报，1996，3
[18]．顾临怡，胡志刚．用SIMULINK实现脉宽／脉频调制中的占空比控制．机床与液压，2003，10
[19]．汪宝明．液压系统的气穴现象及其检测处埋．液压与气动，1999，5
[20]．李启麟，刘红霞．液压传动中能量损失与压力损失．液压与气动，2002，5
[21]．朱建公，文代明．节流调速回路的压力匹配控制．机床与液压，2001，4
[22]．宋春美，许同乐，宋吉江．节流阀在液压系统中的作用与分析．机床与液压，2001，4
[23]．李竟成，曹秉刚，史维祥．电液比例负载敏感控制径向柱塞泵控系统研究．机床与液压，2001，5
[24]．才晓丁．设计限压式变量泵配蓄能器液压系统应注意的几个问题．组合机床与自动化加工技术，1996，1
[25]．徐学新，林真真，张伟．新型液压源回路的设计与研究．液压与气动，2001，3
[26]．高钦和，黄先祥．基于Simulink的重物举升液压控制系统建模与仿真．机床与液压，2001，1
[27]．赵钰．用负载敏感系统精确控制速度．太重技术导报．1996，1
[28]．方治，张春青，王立军，陈赐其．工程机械车辆行驶泵一马达闭式系统分析．建筑机械，2001，6
[29]．冀宏，傅新，杨华勇．内流道形状对溢流阀气穴噪声影响的研究．机械工程学报，2002，38(8)
[30]．王东屏．流动液体中气穴判定的新观点．大连铁道学院学报，2000，21 (2)
[31]．黄建波．液压系统中的气穴问题．华东冶金学院学报，1991，8(1)
[32]．谢卓伟．恒压网络二次转速转矩调节．机床与液压，1997，6
[33]．赵军，王福才，左秀珍．负载传感系统及其应用．液压与气动，2001，5
[34]．A.S.Qureshi著，茅承钧、路长江摘译，节约能量和比例控制的负荷传感系统，国外工程机械，No．6，1983．
[35]. W.T.Stephens、H.N. Underwood, New Concepts in Hydraulic Controls for Mobile Equipment, SAE论文, No. 650669, 1965.
[36]. A.Myers,Controlling Variable Displacement Hydraulic Pumps for Energy Conservation, SAE论文，No. 750807, 1975.
[37]. W. Backe、H.J.Feigel, Neue Moglichkeiten beimelektrohydrau-lischen Load-Sensing, O+P, Nr. 2, 1990
[38]. Manabu Tamura、etc., Development of electric control system for large-sized mining shovel, Proc. of the Second JHPS International Symposium on Fluid Power, Tokyo, 1993.
[39]. Ken. Ichiryu, Recent Trend and Future forcast of Hydraulic System and Control of Hydraulic Excavator, 1995.
[40]. Hitachi Construction Machinery Co.;Ltd., Training text of HITACHI O.H.S.
[40]. Hisanori U, Atsushi OKAJIMA, Hiroyoshi TANAKA, et al. Noise measurement and numerical simulation of oil flow in pressure control valves. JSME Intemational Jourmal, Series B, 1994, 37(2): 336—341
[41]. Ken Ichiryu. Recent Trend and Forecast of Hydraulic Performance of Mobile Load Sensing System with Two Different Types of Pressure Compensated Valves. SAE, 1990(NO. 901552)
[42]. J.Matthews, A.T.Clements. Synchron Control System, Hydraulic & Air Engineering, 1988(2)
[2]．吴根茂，邱敏秀，王庆丰等主编．实用电液比例技术．杭州：浙江大学出版社，1993
[3]．张占松，蔡宣三等主编．开关电源的原理与设计．北京：电子工业出版社，1998
[4]．王懋瑶主编．液压传动与控制教程．天津：天津大学出版社，1987
[5]．严金坤，张培生主编．液压传动．北京：国防工业出版社，1979
[6]．雷天觉．新编液压工程手册．北京：北京理工大学出版社，1998
[7]．缪维平．浅谈液压系统的节能设计．液压与气动，1999，5
[8]．金春花．液压系统效率的分析与对策．液压与气动，1999，5
[9]．赵健．降低液压系统能耗的有效途径．液压与气动，2000，5
[10]．刘宇辉．二次调节静液传动技术的发展及应用．佳木斯大学学报，2001，1
[11]．顾临怡．多执行器负载敏感系统的分流控制发展综述．机床与液压，2000，3
[12]．黄昕．液压系统的节能措施．贵州工业大学学报，2001，4
[13]．李流远．油液含气量对液压系统的影响．液压与气动，2001，1
[14]．谢卓伟．二次调节静液驱动系统的微机数字闭环控制．工程机械，1990．11
[15]．田联房，于慈远．次级调节液压加载试验台的模糊控制器设计．机床与液压，1998，1
[16]．万汉驰．一种多功能阀在轴向柱塞变量泵与定量马达闭式系统中的
应用．建筑机械，1996，11
[17]．贾文沛．二次规矩调节系统的实验研究．太原重型机械学院学报，1996，3
[18]．顾临怡，胡志刚．用SIMULINK实现脉宽／脉频调制中的占空比控制．机床与液压，2003，10
[19]．汪宝明．液压系统的气穴现象及其检测处埋．液压与气动，1999，5
[20]．李启麟，刘红霞．液压传动中能量损失与压力损失．液压与气动，2002，5
[21]．朱建公，文代明．节流调速回路的压力匹配控制．机床与液压，2001，4
[22]．宋春美，许同乐，宋吉江．节流阀在液压系统中的作用与分析．机床与液压，2001，4
[23]．李竟成，曹秉刚，史维祥．电液比例负载敏感控制径向柱塞泵控系统研究．机床与液压，2001，5
[24]．才晓丁．设计限压式变量泵配蓄能器液压系统应注意的几个问题．组合机床与自动化加工技术，1996，1
[25]．徐学新，林真真，张伟．新型液压源回路的设计与研究．液压与气动，2001，3
[26]．高钦和，黄先祥．基于Simulink的重物举升液压控制系统建模与仿真．机床与液压，2001，1
[27]．赵钰．用负载敏感系统精确控制速度．太重技术导报．1996，1
[28]．方治，张春青，王立军，陈赐其．工程机械车辆行驶泵一马达闭式系统分析．建筑机械，2001，6
[29]．冀宏，傅新，杨华勇．内流道形状对溢流阀气穴噪声影响的研究．机械工程学报，2002，38(8)
[30]．王东屏．流动液体中气穴判定的新观点．大连铁道学院学报，2000，21 (2)
[31]．黄建波．液压系统中的气穴问题．华东冶金学院学报，1991，8(1)
[32]．谢卓伟．恒压网络二次转速转矩调节．机床与液压，1997，6
[33]．赵军，王福才，左秀珍．负载传感系统及其应用．液压与气动，2001，5
[34]．A.S.Qureshi著，茅承钧、路长江摘译，节约能量和比例控制的负荷传感系统，国外工程机械，No．6，1983．
[35]. W.T.Stephens、H.N. Underwood, New Concepts in Hydraulic Controls for Mobile Equipment, SAE论文, No. 650669, 1965.
[36]. A.Myers,Controlling Variable Displacement Hydraulic Pumps for Energy Conservation, SAE论文，No. 750807, 1975.
[37]. W. Backe、H.J.Feigel, Neue Moglichkeiten beimelektrohydrau-lischen Load-Sensing, O+P, Nr. 2, 1990
[38]. Manabu Tamura、etc., Development of electric control system for large-sized mining shovel, Proc. of the Second JHPS International Symposium on Fluid Power, Tokyo, 1993.
[39]. Ken. Ichiryu, Recent Trend and Future forcast of Hydraulic System and Control of Hydraulic Excavator, 1995.
[40]. Hitachi Construction Machinery Co.;Ltd., Training text of HITACHI O.H.S.
[40]. Hisanori U, Atsushi OKAJIMA, Hiroyoshi TANAKA, et al. Noise measurement and numerical simulation of oil flow in pressure control valves. JSME Intemational Jourmal, Series B, 1994, 37(2): 336—341
[41]. Ken Ichiryu. Recent Trend and Forecast of Hydraulic Performance of Mobile Load Sensing System with Two Different Types of Pressure Compensated Valves. SAE, 1990(NO. 901552)
[42]. J.Matthews, A.T.Clements. Synchron Control System, Hydraulic & Air Engineering, 1988(2)