基于ORC低温余热发电逆变系统的研究

发布时间：2018-04-10 23:30

本文选题：有机朗肯循环 + 谐波特性　；参考：《山东大学》2017年硕士论文

【摘要】：低温余热发电技术能够对太阳能、地热能、工业余热等多种形式热能进行回收,从而将低品位热能转换为电能再利用。余热能源如果得到有效的回收利用,将会节省大量矿物资源,并且使环境污染也得到减少。随着全世界能源危机的加剧,科研学者对低温余热发电技术的应用也逐渐重视起来。基于有机朗肯循环(ORC)的低温余热发电技术是低温余热发电的主要形式,本文对该技术的发电、逆变问题进行了研究。主要的研究内容如下文所述:首先,详细阐述了低温余热发电系统的结构部件和工作原理,并对该系统所用永磁电机和逆变器进行分析和建模。研究了低温余热发电用永磁电机的函数模型,并得到在在该模型下的电压、转矩、磁链的方程式;研究了三相逆变系统的解耦过程,以及滤波之前的谐波特性,推导出逆变系统的小信号模型,得到了在双极性SPWM调制下逆变系统传递函数。为后述ORC用发电机电磁设计和逆变器环路设计奠定基础。其次,对有机朗肯循环低温余热发电用发电机进行了电磁设计研究,并进行了样机试制及实验研究。永磁同步发电机与其他类型发电机相比具有高效率高功率因数高功率密度的特点,因此本系统选用其作为膨胀机驱动电机进行发电,在整体上提高系统的效率,提升系统功率密度,减少能耗的浪费。然后,根据整个发电系统对于发电机的性能要求和尺寸限制,基于Ansoft电磁仿真对电机进行了电磁设计研究,最后进行了样机试制,并进行了实验研究。再次,对低温发电逆变器的滤波器参数和反馈环路进行设计研究。本文分析了双极性SPWM调制的输出电压谐波特性,并对滤波器参数进行了设计研究,以降低输出电压波形畸变率(THD);当发电机的输出不稳定或负载侧突加突减负载时,会对整体系统造成冲击,严重时造成系统崩溃。因此,本文先对整个逆变系统进行建模,先在连续时域内进行电压电流双闭环设计,然后离散化得到数字系统中的调节器参数,通过该设计使系统具有较快的动态性能和较高的输出精度。对整个逆变系统仿真分析,分别验证系统在负载突变和电源电压扰动情况下的动态响应和稳态性能,由仿真可知系统的电压调整率和负载调整率较好,内环电流能快速抑制电源和负载的波动,从而保持了输出电压的稳定。最后通过系统传递函数的建立分析了系统外部各个变量扰动对系统输出的影响。最后,搭建了整体实验平台,并进行了实验研究。搭建了低温余热发电逆变系统的样机平台并编写软件程序。其中硬件主要包括功率器件的选取、驱动电路的选取、LC滤波器参数的选择和直流侧电容的选择。软件包括主程序,PWM周期中断子程序以及故障处理子程序。分别负责完成DSP系统的初始化设置,信号采样与处理和控制算法的实现,以及对硬件和软件故障信号的判断和处理。测试了逆变器和整个ORC发电系统的运行效率,实验表明文中所设计电机和逆变系统具有良好的运行性能,能够满足ORC低温发电的要求。
[Abstract]:Low temperature waste heat power generation technology to solar energy, geothermal energy, recycling of industrial waste heat and other forms of energy, and the low grade heat energy is converted to electrical energy by heat energy. If effectively recycling, will save a lot of mineral resources and the environmental pollution is also reduced. As the world energy crisis intensifies, the application of research scholars on the low temperature waste heat power generation technology also gradually pay attention. Based on organic Rankine cycle (ORC) of the low temperature waste heat power generation technology is the main form of low temperature waste heat power generation, the power generation technology, inverter is studied. The main research contents as described below: first, elaborated the structure components of low temperature waste heat power generation system and working principle, and the system for permanent magnet motor and inverter are analyzed and studied. The modeling of permanent magnet motor function with low temperature waste heat power generation The number of models, and get the voltage in the model of the torque and flux linkage equation; decoupling of three-phase inverter system, as well as the filter before the harmonic characteristic of small signal model of the inverter system is derived, the bipolar SPWM modulation inverter system transfer function for the ORC generator. The electromagnetic design and inverter design foundation. Secondly, the organic Rankine cycle waste heat power generation were studied by the design of the electromagnetic generator, and the trial and experiments. Compared with other types of permanent magnet synchronous generator power machine has the characteristics of high efficiency and high power factor, high power density, so the system selected as drive motor power generation expansion machine, improve the efficiency of the system as a whole, improve the system power density, reduce energy waste. Then, according to the whole power system for generator The performance requirements and the size limit of Ansoft electromagnetic simulation of electromagnetic design of the motor based on the prototype, and the experimental study was carried out. Thirdly, filter parameters on low temperature power inverter and feedback loop was designed. This paper analyzes the output voltage harmonic characteristics of bipolar SPWM modulation, and the filter parameters the design and research, in order to reduce the output voltage waveform distortion rate (THD); when the generator output is not stable or sudden sudden load side load, the impact on the whole system, the system collapse caused by severe. Therefore, this article first to model the whole inverter system, the first design of double closed loop of voltage and current in the continuous in the time domain, and then get the discrete digital system regulator parameters, output accuracy through the design so that the system has high dynamic performance and faster. The whole inverter system The simulation and analysis, respectively, verification system in the load and power supply voltage disturbances under the dynamic and steady performance, the simulation system consists of a voltage adjustment rate and load adjustment rate is better, the inner current can rapidly suppress power supply and load fluctuations, so as to maintain a stable output voltage. Finally establish the transfer function through the analysis of the system the system of the external disturbance influence of variables on the output of the system. Finally, the overall hardware experimental platform and experimental study. To build a prototype platform of low temperature waste heat power generation inverter system and compile software program. The hardware mainly includes power devices selection, drive circuit selection, selection of DC capacitor and LC filter parameters the choice of software including the main program, PWM cycle interrupt subroutine and fault handling subroutine. Were responsible for DSP system initialization, signal The number of sampling and processing and control algorithm, and the hardware and software of fault signal judgment and processing. The efficiency of the inverter and the whole ORC power system test, experiments show that the motor and inverter system design in this paper has good performance, low power ORC can meet the requirements.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM617

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