Application of doubly-fed variable speed system in motor-generator station is a new field in marine. This paper introduced the theory of doubly-fed variable speed and the design of doubly-fed system, adopted stator flux orientation vector control in induction motor by rotor current control with inverter. A kind of simple and fast starting device was designed, thus the power demand of inverter was reduced greatly. Experiment results showed that doubly-fed induction machine was good for speed adjusting and transient speed change rate was smaller than 1%.
In order to measure industry independent innovation ability more scientifically, a combination evaluation model was established based on adaptive genetic algorithm. The basic steps and application principal of how to establish the model was explained in detail, and concrete operation process of the model was introduced briefly by an example. The empirical study shows that using this model to evaluate can get an accurate and object result, which is valuable for government and enterprises.
In order to solve the coupling of rotor current of d axis and q axis, a new kind of control scheme for double-fed induction machine (DFIM) speed regulation system is proposed based on the theory of auto disturbance rejection controller (ADRC). The ADRC is composed of three parts: tracking-differentiator (TD), extended state observer (ESO) and nonlinear state feedback controller (NSFC). In the ADRC scheme, the coupling of rotor current is regarded as the inner disturbance of DFIM, inputting this disturbance to the input port of the speed regulation system by the feedforward compensation, the speed regulation system can change to the simple integral series connection system or simple linear system. This controller can realize decoupling of rotor current of d axis and q axis, obtaining a good speed tracking performance with small overshoot and fast setting time. Simulation results indicate the rationality and validity of the ADRC.
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