This paper researches observer-based H ∞ synchronization of coronary artery system with input, output time-delays, and external disturbance. By designing chaotic observers for both the master system and slave system, the estimation of the states for master-slave systems has been accomplished. Based on the free-matrix-based integral inequality and Wirtinger-based inequality, the Lyapunov Krasovskii functional (LKF) is constructed to obtain a less conservative synchronization strategy for the chaotic coronary artery system with the existence of state estimation errors and synchronization error. The effectiveness of this control strategy has been demonstrated by some simulations.INDEX TERMS Observer design, H ∞ synchronization, chaotic coronary artery system, free-matrix-based integral inequality, Wirtinger-based inequality, reciprocal convex combination.

Large-scale battery cells are connected in series, which inevitably leads to a phenomenon that the cell voltage is unbalanced. With a conventional equalizer, it is challenging to maintain excellent characteristics in terms of its size, design cost, and equalization efficiency. In order to improve the defects in the above equalization circuit, a novel voltage equalization circuit is designed, which can work in two modes. A bidirectional direct current–direct current (DC–DC) equalization structure is adopted, which can quickly equalize two high or low-power batteries without using an external energy buffer. In order to verify the effectiveness of the proposed circuit, a 12-cell battery 2800-MAh battery string was applied for experimental verification. Computer monitoring (LabVIEW) was adopted in the whole system to intelligently adjust the energy imbalance of the battery pack. The experimental results showed excellent overall performance in terms of equalization was achieved through the newly proposed method. That is, the circuit equalization speed, design cost, and volume have a good balance performance.

Lithium batteries have become the main power source for new energy vehicles due to their high energy density and low self-discharge rate. In actual use of series battery packs, due to battery internal resistance, self-discharge rate and other factors, inconsistencies between the individual cells inevitably exist. Such inconsistencies will reduce the energy utilisation rate and service life of the battery pack, and even endanger its battery system safety. To improve the inconsistency of series battery packs, this study innovatively proposes an equalisation method based on a flyback converter. The residual power of a single cell is used as an index of inconsistency. A simple and reliable flyback converter is used to achieve balanced energy in the entire group, which make the energy is transferred between any batteries. Compared with the traditional equalisation topology, the equalisation topology proposed in this study reduces the number of components and reduces the volume of the equalisation system. Moreover, the primary side of the energy transfer only needs a set of control signals, which reduces the control difficulty. A series of equalisation experiments were performed using 12 series of battery cells. The results show the effectiveness of the proposed new equalisation method.

This paper is based on the Takagi-Sugeno (T-S) fuzzy models to construct a coronary artery system (CAS) T-S fuzzy controller and considers the uncertainties of system state parameters in CAS. We propose the fuzzy model of CAS with uncertainties. By using T-S fuzzy model of CAS and the use of parallel distributed compensation (PDC) concept, the same fuzzy set is assigned to T-S fuzzy controller. Based on this, a PDC controller whose fuzzy rules correspond to the fuzzy model is designed. By constructing a suitable Lyapunov-Krasovskii function (LKF), the stability conditions of the linear matrix inequality (LMI) are exported. Simulation results show that the method proposed in this paper is correct and effective and has certain practical significance.

The high performance of power battery pack is used in the field of electric vehicles widely. With the continuous improvement of the cruising range, the energy imbalance of the power battery has become a limiting factor. This paper analyses and introduces the power battery equalization circuit. According to different circuit topologies, they are divided into two categories: Energy dissipative and non-energy dissipative. We Focused on the analysis of the working principle, advantages and disadvantages of the non-capacity dissipative equalization structure. Finally, this work summarizes the application and development direction of the power battery equalization control in recent years.