Simultaneous Decoupling Voltage Amplitude and Frequency Control of Self-Excited Induction Generators 1=Engineering 2=Electrical Motors and Drive

背景资料。自励感应发电机在以可再生能源(风力和水轮机)或内燃机为基础的原动机的自主(离网)发电系统中得到了广泛的应用。与同步发电机相比，SEIGs的主要优势是价格相对低廉，并具有天然的短路保护特性。SEIGs的主要缺点是电压调节性差，除了依赖于原动机的速度和励磁电容外，还会随着负载的变化而改变产生的电压幅值和频率。在许多情况下，这一缺点导致许多工程师更喜欢使用永磁同步发电机，而不是SEIG。虽然SEIG电压幅值控制的解决方案在文献中得到了广泛的提出，但电压幅值和频率的同时动态控制问题到目前为止还没有得到解析解决。基于附加的可控倾倒负荷[1]或有用的可控负荷[2]、[3]，在稳态时有一些直观可行的解决方案，这些负荷降低了发电系统的效率，不适合动态控制。以控制理论为基础，建立了SEIG电压幅值和频率解耦控制的系统设计方法，实现了电压幅值和频率的独立调节。目标建立了具有电压幅值和频率两个输出的SEIG面向控制的模型。设计了电压幅值和频率的解耦控制。建立了包括STATCOM调幅和调频电压优化器的控制系统框图。搭建了实验试验台，确定了框图参数。在MatLab/Simulink中对控制系统进行了仿真。利用DSPACE或Opal快速建立了控制系统的原型对解耦控制进行了实验研究，探讨了涡旋电机驱动单相感应发电机的关键方法。对于频率和电压幅度通道，在同步参考系[4]中对SEIG的非线性模型进行线性化。分离互连的频率和幅度控制通道。研究的新奇。首次找到了电压幅值和频率同时动态解耦控制的解。测试电压优化技术在频率控制中的适用性。实用价值。该系统将使自主式感应发电机在电压控制品质上与永磁同步发电机相媲美。频率控制的电压优化在虚拟负载中不会产生功率损耗。

Background. Self-excited induction generators (SEIG) have found wide application in autonomous (off-grid) electricity generating systems with prime movers based on renewables (wind- and hydro-turbines) or combustion engines. The main advantage of SEIGs compared to synchronous generators is that they are relatively inexpensive and possess natural short-circuit protection properties. The main drawback of SEIGs is their poor voltage regulation due to the change of both generated voltage amplitude and frequency with the change of load in addition to their dependence on the prime mover's velocity and excitation capacitance. In many cases this drawback results in a lot of engineers prefer to use permanent magnet synchronous generators instead of the SEIG. Whereas the solutions for the voltage amplitude control of the SEIG are widely presented in the literature, the problem of the simultaneous dynamic control of the voltage amplitude and frequency has not been analytically solved till now. There are some intuitive solutions feasible in steady states based on additional controllable dump loads [1] or useful controllable loads like water supply pumps [2], [3] which reduces the efficiency of the generating system and not suitable for dynamic control.Goal of the research. To develop a systematic approach based on control theory for the design of decoupled control of the voltage amplitude and frequency of the SEIG leading to independent regulation of the voltage amplitude and frequency.ObjectivesTo develop a control oriented model of SEIG with two outputs: voltage amplitude and frequency.To design decoupling control of the voltage amplitude and frequency.To develop a block diagram of the control system including STATCOM for amplitude regulation and voltage optimiser for the frequency regulation.To set up an experimental test bench and determine parameters of the block diagram.To simulate the control system in Matlab/Simulink.To prototype rapidly the control system using dSpace or OPAL-RT.To do the experimental research of the decoupled control.To explore the case of single phase induction generator driven by air scroll motor.Key methodologies. Linearisation of the nonlinear model of SEIG in the synchronous reference frame [4] performed for the frequency and voltage amplitude channels. Decoupling interconnected frequency and amplitude control channels.Novelty of the research. For the first time, the solution of simultaneous dynamic decoupling control of the voltage amplitude and frequency will be found. Applicability of the voltage optimisation technique for the frequency control will be tested.Practical value. The proposed system should make autonomous induction generators comparable with permanent magnet synchronous generators in sense of the voltage control quality. The voltage optimisation for the frequency control leads to no power dissipation in dummy loads.