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

背景。自激感应发电机（SEIG）在自主（离网）发电系统中得到了广泛的应用，其原动机基于可再生能源（风力和水力涡轮机）或内燃机。与同步发电机相比，SEIGs的主要优点是相对便宜，并且具有天然的短路保护特性。SEIGs的主要缺点是电压的调节性较差，除了依赖于原动机的速度和励磁电容外，产生的电压幅值和频率也会随着负载的变化而变化。在许多情况下，这个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。虽然文献中对SEIG电压幅值控制的解决方案已经广泛提出，但电压幅值和频率同时动态控制的问题目前还没有得到解析解决。在稳定状态下，有一些直观可行的解决方案是基于附加可控转储负荷[1]或有用的可控负荷[2]，[3]，如供水泵[2]，[3]，降低了发电系统的效率，不适合动态控制。研究的目的。基于控制理论，提出了一种系统的SEIG电压幅值和频率解耦控制设计方法，实现了电压幅值和频率的独立调节。目的建立具有电压幅值和频率两个输出的面向控制的SEIG模型。设计电压幅值与频率的解耦控制。开发控制系统的框图，包括用于幅度调节的STATCOM和用于频率调节的电压优化器。搭建实验试验台，确定方框图的参数。在Matlab/Simulink中对控制系统进行仿真。使用dSpace或OPAL-RT快速制作控制系统原型。对解耦控制进行了实验研究。探讨气涡旋电机驱动单相感应发电机的情况。关键的方法。对同步参考系[4]中SEIG的非线性模型进行了频率和电压幅值通道的线性化。解耦互连频率和幅度控制通道。研究的新颖性。首次找到了电压幅值和频率同时动态解耦控制的解决方案。将测试电压优化技术对频率控制的适用性。实用价值。所提出的系统应使自主感应发电机在电压控制质量上与永磁同步发电机相当。频率控制的电压优化导致虚拟负载无功耗。

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.