当前位置:主页 > 科技论文 > 电气论文 >

LLC谐振变换器的控制与仿真

发布时间:2018-08-30 18:11
【摘要】:从目前来看,由于环境污染新能源的使用越来越广泛。光伏发电就是目前使用新能源的一种主要方式,而谐振功率变换器在光伏发电中起了重要作用,尤其是LLC谐振变换器。例如LLC谐振变换器可以应用于双阶段短时间光伏系统,将输入的不稳定的直流电压转换为稳定的直流电压。对于一般的功率变换器,为了提高能量传递效率增大开关操作频率,但增大开关操作频率时开关损耗也会增加,而在低频率下磁组件电容器成本又会很高,此外对于光伏电池板的寄生电容由于缺乏隔离可能导致泄漏电流,但LLC谐振变换器用于这类系统可以很好的克服这些问题。本文对LLC谐振变换器的建模,控制算法和仿真三个方面进行研究。对于一个典型的LLC变换器具有一个相对精确的非线性动力学模型是必要的,从而确定小信号模型还有传递函数。在建模过程中,首先由电路定律写基本微分方程;LLC谐振电路的电压电流是准正弦电流和电压波形,电磁感应电流和谐振池电容器的电压由正余弦基本部分组成,将这些交流量近似为其基波成分;通过谐波平衡分离正弦和余弦分量的系数得到的近似大信号模型;一个大信号模型谐波平衡可以用来获得稳定状态的工作点,通过设置平衡方程的导数项为零;谐波平衡方程的线性化将系统方程一阶近似,最后求出传递函数。设计合理的控制器使系统在输入电压、共振池参数、输出负载等扰动下调节共振池的增益,保证系统的输出电压始终追随参考电压。在LLC谐振变换器的控制研究部分,设计一个单环或双环反馈控制回路,根据参考电压以调节输出电压。本文所设计的LLC谐振变换器控制器的输出都是用于控制开关操作频率,因此这是一种通过改变开关操作频率来控制共振池增益的方法。在谐振变换器的控制方面分别设计了带有补偿器的双环控制器、模糊逻辑控制器和滑模控制器,并且针对每一个控制器搭建了仿真模型,比较不同控制器的控制效果。
[Abstract]:From the current point of view, due to environmental pollution, the use of new energy is becoming more and more widespread. Photovoltaic power generation is one of the main ways to use new energy at present, and resonant power converters play an important role in photovoltaic power generation, especially LLC resonant converters. For example, LLC resonant converters can be used in two-stage short-time photovoltaic systems to convert the input unstable DC voltage into a stable DC voltage. For general power converters, in order to improve the efficiency of energy transfer, the switching frequency is increased, but the switching loss will also increase when the switching frequency is increased, and the cost of magnetic component capacitors will be very high at low frequency. In addition, the parasitic capacitance of photovoltaic panels may lead to leakage current due to the lack of isolation, but the LLC resonant converter used in this kind of system can overcome these problems. The modeling, control algorithm and simulation of LLC resonant converter are studied in this paper. It is necessary for a typical LLC converter to have a relatively accurate nonlinear dynamic model to determine the small signal model as well as the transfer function. In the process of modeling, the voltage and current of the LLC resonant circuit are quasi sinusoidal current and voltage waveform, and the electromagnetic induction current and the voltage of the resonant cell capacitor are composed of sine cosine. These AC quantities are approximated to their fundamental wave components; an approximate large signal model is obtained by separating the coefficients of sine and cosine components from harmonic balance; and a large signal model harmonic balance can be used to obtain working points in a stable state. By setting the derivative term of the equilibrium equation to zero and linearizing the harmonic equilibrium equation, the first order approximation of the system equation is obtained and the transfer function is obtained. A reasonable controller is designed to adjust the gain of the resonant cell under the disturbance of input voltage, resonant cell parameters and output load, so as to ensure that the output voltage of the system always follows the reference voltage. In the control research of LLC resonant converter, a single loop or double loop feedback control loop is designed to adjust the output voltage according to the reference voltage. The output of the LLC resonant converter controller designed in this paper is used to control the switching frequency, so it is a method to control the gain of the resonant cell by changing the switching frequency. In the aspect of resonant converter control, double loop controller with compensator, fuzzy logic controller and sliding mode controller are designed, and simulation models are built for each controller to compare the control effect of different controllers.
【学位授予单位】:哈尔滨工业大学
【学位级别】:硕士
【学位授予年份】:2017
【分类号】:TM46

【参考文献】

相关期刊论文 前6条

1 阚志忠;张海松;齐飞;;基于预测控制的LLC变换器谐振频率自动跟踪技术[J];燕山大学学报;2016年05期

2 郑锴;李建兵;周东方;李凯;张松振;;LLC谐振功率变换器的大信号建模研究[J];系统仿真学报;2015年05期

3 赵升;贺明智;陈章勇;许建平;;双频率控制LLC谐振变换器分析与设计[J];电力电子技术;2014年04期

4 廖鸿飞;王志强;刘少纯;;浅谈几种谐振变换器的控制方法[J];通信电源技术;2007年01期

5 孙向东,钟彦儒,任碧莹,周炳;恒频移相LCC谐振变换器的设计[J];西安理工大学学报;2003年04期

6 田博,刘娟,杨咏新;基于移相控制的串并联负载谐振变换器研究[J];山东电力技术;2003年06期

相关硕士学位论文 前4条

1 刘秦维;LLC谐振式变换器的滑模控制策略研究[D];浙江大学;2014年

2 管松敏;LLC谐振变换器PWM控制策略和同步整流技术的研究[D];南京航空航天大学;2012年

3 李菊;全桥LLC谐振变换器的混合式控制策略[D];南京航空航天大学;2011年

4 张万凌;一类非线性系统的变结构控制[D];哈尔滨工业大学;2006年



本文编号:2213883

资料下载
论文发表

本文链接:https://www.wllwen.com/kejilunwen/dianlidianqilunwen/2213883.html


Copyright(c)文论论文网All Rights Reserved | 网站地图 |

版权申明:资料由用户35fbf***提供,本站仅收录摘要或目录,作者需要删除请E-mail邮箱bigeng88@qq.com