摘要太阳能作为一种新能源,能为我们的生活提供清洁无污染的能源。作为新能源的代表——光伏发电系统,其产生的电流为直流电,但民用电力以交流供电为主,且太阳能发电最终将走向并网运行,这就意味着太阳能发电必须通过光伏并网逆变器将直流电转换为交流电用以来驱动家用电器等负载。本文研究光伏并网逆变器中铝电解电容的ESR等效模型和电解电容在线监及计算方法。
本文以光伏并网逆变器作为研究对象,通过Matlab电路仿真,监测逆变器中电解电容的电流I和电压U。同时详细分析了电容的ESR等效模型并且对如何计算电容C值进行了详细的公式推导。整个光伏系统的仿真实验建立在开关管工作在连续模式(CCM)下,通过控制占空比(D)控制升压(Boost)电路用以调控这个光伏系统输出电压,最后将输出的直流电通过全桥逆变电路实现直流电到交流电的转换。67351
此外本文从性能退化角度研究了铝电解电容可靠性问题的各个方面,通过对退化理论的分析来推断电解电容的寿命,有利于解决实际中铝电解电容的状态监测、参数计算、寿命预测等问题。本文在各阶段应用了基于性能退化的可靠性研究方法,建立了相应的数学模型,为相关理论和方法的整合提供了明晰的主线。
毕业论文关键词:光伏逆变器;铝电解电容;可靠性;性能退化;预测。
毕业设计说明书(论文)中文摘要
毕业设计说明书(论文)外文摘要
Title The parameter measurement research of electric capacity
Abstract
The solar energy is renewable, providing clean and pollution-free energy for our lives. As a representative of the new energy--solar power generation systems, which generate direct current (DC) power, while mainly civilian need AC power for supplying. Also solar power will go back to the whole power system eventually, which means that solar power had to use inverter trans DC to AC in order to use for home appliances and other loads.. In this study, studying on photovoltaic grid-connected inverter of aluminum electrolytic capacitor Electrolytic Capacitor ESR equivalent model of on-line monitor and calculation methods.
This article takes the grid-connected solar inverter as the object of study, using the Matlab circuit simulation, monitoring the inverter’s electric current of electrolysis electric capacity and voltage. Simultaneously analyzed the ESR equivalent model of electric capacity and calculation of the electric capacity C value. The simulation experiment of entire PV system establishes in the switching valve work under continual pattern (CCM), controls the Boost electric circuit to use to regulate this PV system output voltage by controlling duty-factor (D), finally put direct current into the full-bridge inverter circuit implementation in order to transfer direct current to the alternating current.
Besides, this paper discussed the performance degradation of the aluminum electrolytic capacitor reliability problems, it helps to solve the actual state of aluminum electrolytic capacitors monitoring, parameter calculation, life prediction and related issues. This topic in each stage of application based on performance degradation of reliability research methods, established the corresponding mathematical model, and provides the related theories and methods of the integration clearly.
Keywords : Photovoltaic (PV) inverters; Aluminum electrolytic capacitor; Reliability; Performance degradation; Predictions
目次
1 引言 1
2 课题背景及研究的目的和意义 2
2.1 课题研究的目的和意义