【作者】 黄勇；

【导师】 周林；

【作者基本信息】 重庆大学 ， 电气工程， 2011， 硕士

【摘要】 经济的快速发展带来能源的大量消耗,造成能源危机日益加重,新能源的开发已经成为全球迫在眉睫的重大课题。太阳能是最有潜力的一种新能源,光伏发电是最主要的使用方式之一。但是,由于光伏发电的随机性,必须外加一定容量的储能装置,才能保证独立光伏系统的稳定。超级电容器作为一种新型的储能元件,在储能上具有卓越的潜力。本文针对超级电容器蓄电池混合储能在独立光伏发电系统中应用的关键问题进行研究。论文首先详细介绍了目前独立光伏发电系统的结构,针对目前独立光伏系统中蓄电池功率输出能力不足,以及为满足短时大功率而配置大于经常性负荷容量造成的浪费,提出了一种超级电容器蓄电池混合储能的独立光伏发电系统结构,提高了储能系统的功率输出能力,降低了蓄电池容量配置,延长电池寿命。系统采用两个双向变换器分别对超级电容器和蓄电池进行控制,使超级电容器和蓄电池在功率和电压等级上都可以分开选择,不必与负载或者直流母线满足严格的匹配关系;三个变换器均连接在直流母线上,且直流母线电压保持稳定,有利于变换器设计;另外超级电容器和蓄电池的充放电控制分开进行,控制更加灵活方便。文中建立了超级电容器蓄电池混合储能系统的等效模型,对模型进行了验证,并对混合储能系统性能的提高进行了理论分析。对系统控制环节进行设计,单向变换器在MPPT、恒压模式下和停止工作模式下切换;双向变换器在Boost、Buck和停止工作模式下切换。针对蓄电池充放电的特点,采用一种新颖的电压电流双向双环控制策略,使蓄电池在两个方向均实现稳压或限流功能,在保证响应速度的同时,消除电压静差。针对系统中含光伏电池、超级电容器和蓄电池三种能量源的特点,提出相应的能量管理策略。核心是根据光伏电池和混合储能元件的工作状态,保证三个变换器工作在系统设定的工作模式下,使得系统中的三种电源协调工作,保证系统稳定运行。论文对该方法进行了仿真验证,结果表明混合储能系统能够提高功率输出能力,减小蓄电池容量配置,延长系统使用寿命。更多还原

【Abstract】 Rapid economic development has brought high energy consumption and the energy crisis is increasing. Therefore, the new energy development has become the world’s imminent major issue. Solar energy is the most promising new energy and photovoltaic power generation is one of the most main way to use it. However, due to the randomness of photovoltaic power generation, the energy storage device must be additional to ensure the stability of stand-alone photovoltaic system. The ultracapacitor is a new energy storage component and has excellent energy storage potential. This paper researches the key issues of ultracapacitor- battery hybrid energy storage system used in stand-alone photovoltaic system.It firstly introduces the present circuit structures of stand-alone photovoltaic system. Because of the battery power output capacity is insufficient, so it is necessary to provide greater capacity to meet the short-term high-power load but it lead to waste. This paper proposes a kind of ultracapacitor- battery hybrid energy storage system structure. It improves power output capacity of energy storage system, reduces the battery capacity allocation, extends battery life. This structure uses bi-direction converter for ultracapacitor and battery respectively. It makes ultracapacitor and battery can separate choice in power and voltage level, not to meet strict matching relation with load and dc bus voltage. It is advantage for converter design. The charging and discharging of ultracapacitor and battery can control separately and more flexibly.This paper established the ultracapacitor- battery hybrid energy storage system equivalent model and analyses how to improve system performance in theory. It designs the system control part. The direction converter has three modes-MPPT, constant voltage and stop working, the bi-direction converter works in Boost, Buck and stop mode, they switch three modes between. For charging and discharging characteristics of battery, this paper proposes a novel bi-direction voltage and current loop control strategy in order to realize battery voltage and current limiting in both direction, this can guarantee the response speed and eliminate voltage difference.For the characteristics of photovoltaic cells, ultracapacitor and battery, it presents the corresponding energy management strategy. The core is to ensure three converters work in set mode and three power sources coordinating and stable work according to the photovoltaic cells and hybrid energy storage components working condition. The control strategy is verified through simulation method, the results show that the hybrid energy storage system can increase the power output capacity, reduce battery capacity allocation, prolong the system working life.更多还原