毕业设计（论文）-单相交直交SPWM变频电源的设计精选.doc

摘 要 由于传统能源的枯竭，各国对环境保护的重视以及现存电力系统的种种弊端，分布式发电将在未来的供电系统中发挥越来越重要的作用。近年来以燃料电池发电技术，微型燃气轮机发电技术，光伏电池发电技术和风力发电技术为代表的新型分布式发电技术发展迅速。但是分布式发电技术发出的电都不是与电网供电系统相同的交流电，无法与大电网联网或者直接供给普通负载使用，都需要变频装置将其变换成负载可以使用的交流电或者与大电网电压、频率相匹配的工频交流电。因此，针对特定的分布式发电技术研究与其相配套的变频电源就很有必要。 本文针对内燃机拖动永磁发电机的中小功率分布式发电系统，设计一套变频电源，将发电机发出的中频交流电变换为相电压220V ,频率50Hz的工频交流电。在论述和分析了变频电源及其控制技术发展的概况和趋势的基础上，结合本课题任务的实际情况，设计了一套中小功率的逆变电源。系统中PWM控制信号采用专用集成芯片SA4828生成，减轻了控制器的工作量也提高了系统的可靠性。控制器选用集成了 A/D转换器的单片机，使得系统的硬科复杂性降低，提高了可靠性。 Abstract Since the exhaustion of the traditional energy, the high opinion of the environment anda variety of defeats of the current power system, distributed generation would bring into play more and more significant action. Recent years, some new distributed generation technology,such as fuel cell, micro gas turbine, solar cell and wind power generation, developed rapidly.But electricity generated by them can not merge into the electrified。 netting or supply the loads directly. It should be converted to the electricity with the phase to ground voltage is 220V,and the frequency is 50Hz to merge into the electrified wire netting or supply the neighboring lngdc. This paper introduces a medium and small variable frequency power supply for a distributed generation, which including a permanent magnetism dynamo pulled by a diesel engine, to converts the medium frequency electricity generated by the dynamo into the electricity which the ground voltage is 220V, the frequency is 50Hz. Based on surveying the development of variable frequency power supply and analyzing its development tendency, and considering the practical features of the assignment, the conversion system is designed as follows: it selects the 3-phase Pulse Width Modulation Engine SA4828 as the PWM control signals generator; it chooses the single-chip-computer PIC16F877 as the microcontroller, which integrated the A/D modulation, which cuts down the complexity of the hardware system and strengthens the dependability of the system