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Aiming at the low-frequency oscillation (LFO) phenomenon in high-speed railways, this paper proposes a feedback linearized virtual inertia control (VIC) strategy of the traction converter based on a sliding mode observer (SMO) to improve the robustness of the system and suppress the occurrence of LFO. First, to optimize the total harmonic distortion of the traction grid-side current, the inner loop controller is designed as the feedback linearization control. Then, the voltage outer loop is designed as a combination of the VIC designed in this paper and SMO, which enhances the system inertia and reduces the impact of external interference on the system, while reducing the controller's demand for electrical power on the DC-side. Furthermore, a small-signal model is established to analyze the stability of the single-phase vehicle-grid system under the proposed control. The influence of the control parameters on stability is discussed in detail. Finally, the comparison of software simulation and hardware-in-the-loop experimental results between traditional PI control, feedback linearization control, feedback+SMO, feedback+VIC and the proposed control method shows that the proposed control has better dynamic and static characteristics, and can effectively inhibit the occurrence of LFO. [ABSTRACT FROM AUTHOR]

This paper presents a multi-stage series model predictive control (MS-MPC) for PMSM drives in order to further improve the control performance of MPC. Firstly, the basic principle of conventional MPC is introduced. Then, the multi-stage series MPC is proposed in this paper, in which the cost functions of different prediction instant are adopted to form series control structure. In this method, the current prediction trajectory of one voltage vector is extrapolated to multiple control periods, and the control performances of every voltage vector during multiple control periods are evaluated by multi-stage series cost functions. Additionally, the implementation process of the proposed method is described. Finally, the comparison experiments between the conventional MPC and the proposed method show that the proposed method can effectively reduce the switching frequency under the same control frequency. In addition, the improvement of current control performance can be achieved by the proposed method under the condition of the same switching frequency. [ABSTRACT FROM AUTHOR]

This paper presents a direct voltage control method for interior permanent magnet synchronous motors (IPMSMs) with a single speed regulator. The method achieves maximum torque per ampere (MTPA) operation by controlling the magnitude and the angle of the voltage vector. For that, the mathematical model for the MTPA trajectory of the IPMSM is derived in the voltage plane. As such, no current sensor is needed, which makes the proposed strategy tolerant to current sensors failure unlike cascaded control loop based methodologies. Although no current sensor is used, the control strategy tracks MTPA trajectory by taking into account both voltage and current limits of the machine. The complete MTPA derivation in the voltage plane is presented in this paper; but, only the final solution is needed for real-time implementation. Henceforth, the simplicity of the control scheme combined with its current sensor dependence free characteristics make it a good candidate for real-time implementation in vehicular applications. The concept is developed and evaluated experimentally on a 10-HP IPMSM. [ABSTRACT FROM AUTHOR]

This paper presents an adaptive radial basis function (RBF) network based speed control approach for interior permanent magnet synchronous machine (IPMSM) based vehicles. The presented control strategy achieves speed tracking without current measurement or control by acting directly on the machine's voltages. As a result, the current control loop is avoided, greatly simplifying the overall control strategy when compared to most existing speed control schemes. Moreover, no parameter knowledge is required unlike other control strategies. Furthermore, the closed-loop control system's stability is guaranteed by a Lyapunov theorem. Simulation and experimental results for different scenarios along with comparison against the well-established field oriented vector control technique demonstrate the controller's satisfactory behavior in both transient and steady state. The proposed method yields 99% and 97% tracking accuracy in the presence of parametric uncertainties and friction nonlinearities, respectively. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of controlling a hybrid energy storage system (HESS) for electric vehicles. The storage system consists of a fuel cell (FC), serving as the main power source, and a supercapacitor (SC), serving as an auxiliary power source. It also contains a power block for energy conversion consisting of a boost converter connected with the main source and a boost–buck converter connected with the auxiliary source. The converters share the same dc bus, which is connected to the traction motor through an inverter. These power converters must be controlled to meet the following requirements: 1) tight dc bus voltage regulation, 2) perfect tracking of the SC current to its reference, and 3) asymptotic stability of the closed-loop system. A nonlinear controller is developed, on the basis of the system nonlinear model, making use of Lyapunov stability design techniques. The latter accounts for the power converters' large-signal dynamics and for the FC nonlinear characteristics. It is demonstrated using both a formal analysis and simulations that the developed controller meets all desired objectives. [ABSTRACT FROM PUBLISHER]