发布时间 : 星期四 文章输出并联组合型双Cuk逆变器研究更新完毕开始阅读147da306964bcf84b9d57b4b
摘要 摘要
目前，太阳能发电技术已经得到了广泛的发展和应用。然而，光伏电池输出的电压等级比较低，而且变化范围比较宽，传统的桥式逆变器已经不能满足需求。本文研究的是一种新型逆变器，它既可以升压也可以降压，并且对直流侧的电压有很好的适应性，适合于光伏并网系统。
本文在深入了解Cuk型DC/DC变换器工作原理的基础上，对其进行了仿真，得出该变换器在开关管采用单极性PWM控制时可以输出半个周期的正弦波。由此想到，如果有两个Cuk变换器并联就可以输出整个正弦波。从而得到了我的主电路拓扑。本文对单电源和双电源时该逆变器的工作原理都进行了详细分析。
本文对输出并联组合型双Cuk逆变器采用小信号状态空间平均法进行了小信号建模。然后根据该逆变器的工作原理对其进行了开环仿真。紧接着根据闭环控制原理对双电源和单电源输入进行了闭环研究。最后针对单电源输入时分压电容的均压问题提出了两种均压方法，分别为冗余开关均压法和调制波修正均压法，并分别进行了仿真验证。结果表明，这两种方法均压效果都很好。
关键词:单极性PWM；双Cuk电路；输出并联；闭环控制；均压
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Abstract Abstract
At present, solar power generation system has received extensive
development and application. However, the output voltage level of photovoltaic battery is low, and the range is wide, so the traditional bridge type inverter cannot meet the demand. In this paper a new type of inverter is presented. It can not only boost but buck the input voltage, and has a good adaptability for the DC side power supply voltage variation, so it can be applied to the photovoltaic power system.
Based on the understanding of the Cuk circuit and its simulation, concludes that if adopt the single polarity PWM control the switches, a half cycle of sine wave could be gained. So if there are two Cuk converters in parallel can output the sine wave. So my main circuit topology has been obtained. In this paper, the working principle of the inverter when the single power supply and dual power supply are analyzed in detail.
In this paper, the small signal state space average method is used for small signal modeling. Then according to the working principle of the inverter complete the open loop simulation. And according to the principle of closed loop control complete the study of the closed loop with double power source and single power source. In order to solve the problem of uneven distribution of capacitor voltage, this thesis proposes two control schemes: a redundant switch method of voltage sharing between input-capacitor and the modulation wave corrected method of voltage sharing between input-capacitor. The working principle of the two schemes has been analyzed by theory and simulation, and the results proved the effectiveness of the two methods.
Keywords ：unipolar PWM ;Cuk circuit; output in parallel; closed loop control;
equalizing
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目 录
摘要 ........................................................................................................................ I Abstract ................................................................................................................. II 第1章绪论 ........................................................................................................... 1
1.1 课题背景 ................................................................................................. 1 1.2背景技术 .................................................................................................. 2 1.3非隔离型单级逆变器研究现状 .............................................................. 2
1.3.1加入无源网络的单级逆变器 ........................................................ 2 1.3.2 新型单级逆变器 ........................................................................... 4 1.4本文研究的主要内容 .............................................................................. 5 第2章双电源输入的输出并联组合型双Cuk逆变器 ...................................... 7
2.1逆变器拓扑 .............................................................................................. 7
2.1.1Cuk电路基本原理 ......................................................................... 7 2.1.2Cuk电路的仿真 ............................................................................. 8 2.1.3逆变器的拓扑 ................................................................................ 8 2.2双电源输入的输出并联组合型双Cuk逆变器 ..................................... 9
2.2.1控制方式 ........................................................................................ 9 2.2.2四种工作模式 .............................................................................. 10 2.3参数设计 ................................................................................................ 12 2.4闭环控制 ................................................................................................ 13
2.4.1连续工作状态下Cuk型DC/DC变换器的建模 ....................... 13 2.4.2闭环控制方式 .............................................................................. 16 2.5并网研究 ................................................................................................ 16
2.5.1并网滤波器 .................................................................................. 16 2.5.2并网控制方式 .............................................................................. 18 2.6总结 ........................................................................................................ 19 第3章单电源输入的输出并联组合型双Cuk逆变器 .................................... 19
3.1工作原理 ................................................................................................ 20
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3.2仿真研究 ................................................................................................. 21 3.3两种均压措施 ......................................................................................... 22
3.3.1冗余开关均压法 ........................................................................... 23 3.3.2调制波修正均压法 ....................................................................... 24 3.4总结 ......................................................................................................... 24 第4章硬件电路设计 .......................................................................................... 25
4.1主电路参数设计 ..................................................................................... 25
4.1.1电容设计 ....................................................................................... 25 4.1.2开关管设计 ................................................................................... 26 4.2控制电路设计 ......................................................................................... 26
4.2.1驱动电路设计 ............................................................................... 26 4.2.2信号产生电路设计 ....................................................................... 27 4.2.3输出电压检测电路设计 ............................................................... 29 4.2.4死区电路设计 ............................................................................... 29 4.2.5 PI调节器设计 .............................................................................. 30 4.3总结 ......................................................................................................... 30 第5章仿真分析 .................................................................................................. 31
5.1PSIM仿真软件简介 ............................................................................... 31 5.2开环仿真 ................................................................................................. 32 5.3闭环仿真 ................................................................................................. 34
5.3.1电压瞬时值闭环控制方式 ........................................................... 34 5.3.2电流瞬时值闭环控制方式 ........................................................... 38 5.4并网仿真 ................................................................................................. 39 5.5单电源输入时的均压仿真 ..................................................................... 40
5.5.1冗余开关均压法 ........................................................................... 40 5.5.2调制波修正均压法 ....................................................................... 41 5.5.3两种均压法比较 ........................................................................... 43 5.6总结 ......................................................................................................... 43 结论 ...................................................................................................................... 44
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