Haozhe Liu

Analysis, Comparison, and Discussion of Control Strategies for Dual Stator-Winding Induction Generator DC Generating System

This paper presents four types of control strategies for a dual stator-winding induction generator DC generating system as well as their analysis, comparison, and discussion. These four types of control strategies include control-winding flux orientation control, control-winding voltage orientation control, control-winding direct power control, and instantaneous slip frequency control (ISFC). The ISFC strategy is described in detail for first employed in dc generating application, and the other strategies are briefly introduced and their performances are also summarized for comparison. The characteristics of control strategies are compared from four aspects: 1) system performance; 2) key components; 3) control principles; and 4) applications. From the comparison results, it can be inferred that all these four types of control strategies have some advantages, especially the ISFC. They can find suitable applications.

Control and Performance of Five-Phase Dual Stator-Winding Induction Generator DC Generating System

In this paper, the five-phase dual stator-winding induction generator dc generating system with the static excitation controller is presented, and two kinds of control strategies for this system are proposed. In this generator, the cage-type rotor is employed, and two sets of five-phase windings are placed in the stator, namely, the power winding and control winding. Using the instantaneous power theory, the control-winding-flux-oriented control (CWFOC) strategy without harmonic injection is obtained. To improve power density, the CWFOC with harmonic injection is proposed as well. For these two strategies, the detailed implementation is studied. The results (simulation and experiment) support the correctness and effectiveness of the proposed control strategies, and the corresponding results show that, using the CWFOC strategy with harmonic injection, the output power of this system can be improved by about 11%.

Control strategy for five-phase dual stator-winding induction generator DC generating system

This paper presents a dc generating system based on the five-phase dual stator-winding induction generator (DWIG) with the static excitation controller (SEC), and also investigates its control strategy. In this five-phase DWIG, the cage-type rotor is employed and it has two sets of five-phase stator windings (power winding and control winding). Based on the instantaneous power theory, a control winding field oriented control (CWFOC) strategy considering third-harmonic injection is proposed. The simulation results support the proposed control strategy, the five-phase DWIG dc generating system can have a good performance.

Harmonic voltage control for five-phase induction generator system with direct torque control

This paper investigates the harmonic voltage control strategy of direct torque control for five-phase induction generator (IG) system. In high/medium power applications, the generating function requires the performance of fast dynamic response, good static performance and high utilization of the dc bus voltage. For IG generating system, the direct torque control strategy has the advantages of easy implementation and great performances with load. Harmonic current injection is studied to improve the torque density of multi-phase machine. However, the direct torque control is not fit for that current control loop is not existed. To solve this problem, harmonic voltage control is proposed to study the performance of five-phase IG system. The simulation results and experimental results are given to verify the control strategy.

Control strategy of AC&DC hybrid generating system based on dual stator-winding induction generator for micro-grid application

For hybrid AC& DC micro-grid, this paper proposes a new generating system based on dual stator-winding induction generator (DWIG). This generating system can realize bidirectional energy flow, reduce the number of converters and simplify the structure of micro-grid. To meet the requirement of supplying AC and DC power simultaneously, this paper proposes the control winding voltage oriented (CWVO) control strategy on the basis of instantaneous reactive power theory. Through the analysis of simulation results, the feasibility and accuracy of this generating system and its control strategy is validated. This paper lays the foundation for future research for hybrid AC& DC micro-grid.

Modeling of five-phase dual stator-winding induction generator with third harmonic injection

In this paper, the model of the third-harmonic-injected five-phase dual stator-winding induction generator (FPDWIG) is presented. There are two sets of five-phase concentrated stator windings in this generator. One is called as the control winding, the other is termed as the power winding. For improving the power density, the third harmonics are injected in this generator. With the consideration of the differences of the fundamental and third harmonic spaces, the model of the third-harmonic-injected FPDWIG is built in the rotating d1-q1-d3-q3 arbitrary reference frame. The dynamic equivalent circuits of FPDWIG in the rotating d1-q1-d3-q3 arbitrary reference frame are given. Based on this method, FPDWIG simulating model is built in the MATLAB/SIMULINK and the simulation results is given for verification.

Dual-frequency SVPWM strategy for five-phase voltage source inverter

This paper proposes a novel dual-frequency space vector pulse width modulation strategy for the five-phase voltage source inverter, which contains fundamental frequency and third harmonic frequency. The proposed strategy has the advantages of half-wave symmetry, outputting dual frequency voltages and currents, reducing the switching times, and balancing the switching times of top device and bottom device. Based on the fast fours transformer (FFT) analysis, the third harmonic components are trade with the command value. It indicates that the two components (fundamental and third) are regulated greatly by this proposed strategy. The principle and performance of this strategy are verified by the MATLAB simulation finally.

Asymmetrical model of DWIG for aircraft variable frequency AC generating system

This paper presents the mathematical model of dual-stator-winding induction generator (DWIG) for aircraft variable frequency ac generating system under asymmetric operation. Firstly, the asymmetric mathematical model of DWIG under the A-B-C three-phase static coordinate system is built. Then, for the asymmetric operation, the zero-axis component is considered, and the asymmetric mathematical model of the DWIG in the d-q-0 three-phase orthogonal rotating coordinate system is obtained. Based on this, the simulation of the DWIG and whole system is built in the MATLAB/ SIMULINK Simulation and experiments are carried out under single-phase full load, two-phase full load and three-phase asymmetric load. The results of simulation and experiment prove the correctness of the mathematical model.