This paper proposes a dual-frequency discontinuous space vector pulse width modulation (DFDSVPWM) for a five-phase voltage source inverter with harmonic injection. In this modulation, for dual-frequency voltage output and reduction of switching losses, two different zero-vector-inserted modes are flexibly employed by alternatively using two types of zero vectors. Based on the comparison with conti...

A control-winding direct power control (CWDPC) strategy for a dc generating system based on the five-phase dual-stator winding induction generator is proposed and investigated in this article. For this generator, the flux-oriented control is usually employed in the previous work mainly for the sake of good static performance. However, the present control strategy has the limitation of the further enhancement of the dynamic properties. This article explores a CWDPC strategy to upgrade the dynamic performance of this generating system. The fundamental active power of the five-phase control winding (CW) relates to its dc bus voltage while the dc bus voltage on the five-phase power-winding (PW) side is related to the control of five-phase CW fundamental reactive power. By replacing inner current loops to power control loops, the CW instantaneous fundamental active and reactive powers are calculated through the power observer and regulated directly through two power-control loops. In the transient process, the CW fundamental active power changes slightly while the reactive power can be quickly controlled for fast recovery of the dc bus voltage on the five-phase PW side. As the system has an additional control degree of freedom, the third harmonic is also considered in the proposed strategy, and the corresponding implementation is given as well. The simulation and experimental results demonstrate that using the proposed CWDPC strategy, the system has shorter transient time and lower voltage change in the dynamic response than the flux-oriented control strategy, which means the dynamic performance is further improved.

Dual stator-winding induction generator (DWIG) is attractive in stand-alone power systems, and the aim of this paper is to develop the dc generating system of five-phase DWIG with an open phase. First, the relationship between flux and torque is constructed based on the reduced-order transformation, modified flux, and current. Second, the relation between modified voltage and current on the dq plane is constructed. The current of fundamental plane is used for the control loop of the power-winding voltage and control-winding voltage, respectively. Third, the current of the modified secondary subspace plane is used to control the five-phase DWIG operation at minimum control-winding loss. Finally, the simulation and experimental results are given to verify that the amplitude of phase current and output voltage can be regulated effectively by the proposed control strategy.

This paper presents a third-harmonic optimization method for a five-phase dual stator-winding induction generator (FPDWIG). In this generator, a cage-type rotor is used, and there are two sets of five-phase stator windings. Based on the principle of nonsinusoidal power supply, the third harmonic is injected and optimized. By minimizing the cost function of the oscillation of flat level of air-gap flux density, the optimal ratio of the third harmonic is determined to make the waveform of the air-gap flux density flat-topped for better core utilization. The corresponding implementation based on the control-winding flux-oriented control with the consideration of different load conditions is given, as well. The simulation and experimental results verify the correctness and validity of the proposed optimization method, and by using this method, the desired air-gap flux density can be obtained, and the output power of the FPDWIG can be increased.

Dual stator-winding induction generator (DWIG) is one kind of emerging multiport electrical machine. It has become a promising direction in the last two decades, especially for stand-alone power systems and renewable energy power systems. This paper mainly focuses on the DWIG with similar-poles stator windings and cage-type rotor. An overview of DWIG and its system is given. Recent advances of this generator in system topologies, mathematical model, optimal design, control strategies, and performance analysis are presented. The developments and potential applications of the DWIG-based system are also discussed.

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.

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%.

High volume from urban freeway off-ramps coupled with extensive traffic weaving and limited capacity at downstream intersections create major bottlenecks in urban road networks. This article presents an integrated design model to eliminate traffic weaving and to maximize the section's overall capacity by using the presignal and sorting area concept. The selection of movements controlled by the presignal, the layout of the section, and the signal timing are optimized in a uniform framework by a mixed-integer nonlinear program model. The mathematical model was linearized and solved using the standard branch-and-bound technique. Extensive numerical analysis and a case study validate the effectiveness of the proposed integrated model in improving capacity with the comparison of conventional design under various geometric configuration and traffic demand pattern scenarios. The proposed model has promising application at locations where the queuing space is long enough and the number of exit lanes is enough to receive the traffic stream from the sorting area.

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.

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.

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.

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.

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.

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.