This paper proposes a novel hybrid equalizer circuit (HEC) for a battery management system (BMS) to implement the passive HEC (P-HEC), active HEC (A-HEC), or active/passive (AP-HEC) with the same equalizer circuit architecture. The advantages of an HEC are that it is simple, cost-effective, highly energy efficient, and fail safe. The P-HEC can further use a cooling fan or heater instead of a conventional resistor as a power dissipation element to convert the energy of the waste heat generated by the resistor to adjust the battery temperature. Even if the P-HEC uses the resistor to consume energy as in conventional methods, the P-HEC still dramatically improves the component lifetime and reliability of the BMS because the waste heat generated by the equalizer resistor is outside of the BMS board. Three significant advantages of an A-HEC are its (1) low cost, (2) small volume, and (3) higher energy efficiency than the conventional active equalizer circuits (AECs). In the HEC design, the MOSFETs of the switch array do not need high-speed switching to transfer energy as conventional AECs with DC/DC converter architecture because the A-HEC uses an isolated battery charger to charge the string cell. Therefore, the switch array is equal to a cell selector with a simple ON/OFF function. In summary, the HEC provides a small volume, cost-effective, high efficiency, and fail-safe equalizer circuit design to satisfy cell balancing demands for all kinds of electric vehicles (EVs) and energy storage systems (ESSs).

In most battery management system (BMS) circuit designs, the analog front end (AFE) chip is used to get the series cell voltage of the battery pack. However, it can lead to incorrect calculations by the BMS, causing errors in battery information, failures in protection control, and triggering a battery system fire accident if the AFE chip is abnormal. Unfortunately, the BMS will never know the correct of measured results if it is measured by a single AFE chip. This paper proposes a redundant series voltage measurement system (RSVMS) for the series cell voltage of the battery pack. The original AFE is referred to as the main AFE (m-AFE). The RSVMS can be regarded as redundant AFE (r-AFE). In this paper, the r-AFE consists of a series cell selector and an analog-to-digital (ADC) converter with an isolated communication function to transmit measurement results to the microcontroller unit (MCU) of the BMS. Due to the hardware requirements of functional safety, it does not allow using two identically designed hardware as redundant systems. To satisfy the hardware level of functional safety and to minimize the hardware cost and size, the series cell selector of r-AFE shares the same hardware circuit as the Active Hybrid Equalizer Circuit (A-HEC). The cell selector of A-HEC is composed of the back-to-back MOSFET switch array with a simple ON/OFF function. The MCU of BMS will identify the abnormal of voltage measurement results when the difference of m-AFE and r-AFE is over the threshold. In summary, r-AFE can ensure the accuracy of cell voltage measurement for m-AFE to avoid significant errors when estimating battery information and avoid disaster caused by failure or malfunction of protection functions. In addition, the m-AFE and r-AFE are two independent designs to avoid similar errors caused by identical circuit configurations.

This paper proposes a decentralized robust constrained cost fuzzy controller (DRCCFC) design for nonlinear descriptor interconnected systems (DIS) with uncertainties. The considered nonlinear DIS is modeled using Takagi–Sugeno fuzzy model (T-S FM) with fuzzy rules and strong interconnections. To derive sufficient stability conditions, the quadratic Lyapunov function (QLF) and free-weighting function (FWF) are defined. In contrast to the existing control approaches, the proportional–derivative feedback (PDF) control is introduced in this paper. Using the PDF control techniques, the regular and causal problems of the system can be solved easily. Based on the PDF control technique and constrained cost control (CCC) function, a set of fuzzy controllers are designed to effectively control the Takagi–Sugeno descriptor interconnected systems (T-S DIS). Then, the proposed sufficient conditions for the T-S DIS are derived in the form of linear matrix inequalities using the Schur complement technique. Finally, two simulation examples are provided to demonstrate the validity of the proposed control scheme.

Fault-tolerant and redundant power supplies are often used in systems that require high reliability, such as data servers, telecommunications, and power supplies for autonomous driving function. Using diode is a simple method to keep uninterrupted power supply that is, using diode in series with each power path to become “Diode ORing”. However, in high current application, the voltage drop of the diode will result huge power loss. Even if that a low voltage drop of Schottky diode is adopted. This article proposes a simple P MOSFET control circuit that can implement the function of P MOSFET as a diode, that is, to ensure unidirectional conduction of current and maintain a low conduction voltage drop, thereby reducing losses. The circuit has the advantages of low forward voltage drop, without IC control, no need for additional auxiliary power supply, and the ability to block current flow between different power supplies that is the reverse current blocking is achieved. A circuit for implementing ORing of two power supplies to increase system redundancy or power capacity is provided. Simulation results verify the feasibility of the proposed control circuit.

This paper discusses a passive control issue for Nonlinear Time-Varying (NTV) systems subject to stability and attenuation performance. Based on the modeling approaches of Takagi-Sugeno (T-S) fuzzy model and Linear Parameter-Varying (LPV) model, a Parameter-Dependent Polynomial Fuzzy (PDPF) model is constructed to represent NTV systems. According to the Parallel Distributed Compensation (PDC) concept, a parameter-dependent polynomial fuzzy controller is built to achieve robust stability and passivity of the PDPF model. Furthermore, the passive theory is applied to achieve performance, constraining the disturbance effect on the PDPF systems. To develop the stability criteria, by introducing a parameter-dependent polynomial Lyapunov function, one can derive some stability conditions, which belong to the term of Sum-Of-Squares (SOS) form. Based on the Lyapunov function, two stability criteria are proposed to design the corresponding PDPF controller, such that the NTV system is robustly stable and passive. Finally, two examples are applied to demonstrate the effectiveness of the proposed stability criterion.

This paper investigates the Static Output (SO) control issue of the disturbed nonlinear stochastic system, which achieves passivity. Through the application of fuzzy sets and the stochastic differential equation, a Takagi–Sugeno (T-S) fuzzy model with the terms of multiplicative noise and external disturbance can be constructed to describe the considered systems. Furthermore, the Parallel Distributed Compensation (PDC) concept is used to design a fuzzy controller exhibiting an SO feedback scheme structure. To attenuate the effect of external disturbance, the PDC-based SO fuzzy controller is designed to exhibit passivity. During the derivation of some sufficient conditions, a line-integral Lyapunov function is utilized to avoid the conservative term produced using the derivative membership function. Using converting technologies, a stability criterion belonging to Linear Matrix Inequality (LMI) forms is proposed such that the derived conditions are convex hull problems and are solved through an optimization algorithm. Then, the proposed criterion is used to discuss the problem of SO controller design of ship fin stabilizing systems with added disturbance and noise.