Search

A 12-V motor drive system using an onboard battery is promising in vehicle applications, e.g., to rotate an air pump to adjust its air delivery to the burner, thereby providing autonomous exhaust temperature control for the conventional diesel engine vehicle. The 12-V/1-kW motor drive system proposed in this paper consists of a series-resonant LLC MOSFET full-bridge converter, which provides high-efficiency power transfer by implementing zero voltage switching and boosts the dc bus to $\sim$300 V, and an insulated-gate bipolar transistor inverter, which provides the high-side phase currents to a 1-kW/6000-r/min brushless dc motor (BLDC). This design secures the high efficiency, low cost, and low volume. Meanwhile, with the variable output voltage of this dc/dc converter, this paper realizes a commutation torque-ripple reduction method, which will minimize the mechanical vibration. Experimental results on this prototype system demonstrate that: 1) the LLC dc/dc part efficiency is 97.6% with 92% of the inverter efficiency; and 2) the motor commutation torque ripple is reduced close to zero. [ABSTRACT FROM PUBLISHER]

This paper proposes an interleaved equalization architecture for series-connected lithium-ion battery strings, which can deliver energy from a battery module to the cells in the next adjacent battery module, resulting in an enhancement of the equalization current and efficiency. Particularly, the global equalization is achieved without the need of additional stage circuits to balance among modules, leading to a small size and low cost. A two-module equalizer based on resonant LC converter and buck converter with soft switching is implemented to verify the validity of the proposed interleaved architecture. Furthermore, a self-learning fuzzy logic control (SLFLC) algorithm is employed to online regulate the equalization period based on the voltage difference among cells and the cell voltage, not only greatly abbreviating the balancing time but also effectively preventing overequalization. The SLFLC has the outstanding advantages of high balancing precision, easy implementation, and strong robustness. Experimental results demonstrate that the proposed equalizer has good balancing performances with soft switching and high efficiency, and achieves zero-voltage gap among cells. Moreover, the proposed SLFLC algorithm abridges the total equalization time by about 27%, and reduces the equalization cycles by about 59% compared with the traditional control algorithm. [ABSTRACT FROM AUTHOR]

In this paper, a control strategy is presented for a high-performance capacitively loaded loop (LLC) multiresonant dc–dc converter in a two-stage smart charger for neighborhood electric vehicle (NEV) applications. It addresses several aspects and limitations of LLC resonant dc–dc converters in battery charging applications, such as very wide output voltage range while keeping the efficiency maximized, implementation of the current mode control at the secondary side, and optimization of burst mode operation for current regulation at very low output voltage. The proposed control scheme minimizes both low- and high-frequency current ripples on the battery while maintaining stability of the dc–dc converter, thus maximizing battery life without penalizing the volume of the charger. Experimental results are presented for a prototype unit converting 390 V from the input dc link to an output voltage range of 3–72 V dc at 650 W. The prototype achieves a peak efficiency value of 96%. [ABSTRACT FROM PUBLISHER]

This paper presents a high-gain boost converter (three-level converter and transformerless converter) for fuel cell (FC) vehicle applications. An original nonlinear control law based on the flatness principle for distributed dc generation is studied. Utilizing the flatness property, we propose simple solutions to the system performance and stabilization problems. The design controller parameters are straightforward and autonomous at the operating point. To validate the proposed method, a prototype FC power converter (1.2-kW three-level boost converter) is developed in the laboratory. The proposed control law is implemented with a digital estimate in a dSPACE 1104 controller card. The experimental results from the laboratory using a 1200-W and 46-A polymer electrolyte membrane FC (PEMFC) verify that this is a good control scheme. [ABSTRACT FROM PUBLISHER]