International Journal of Circuit Theory and Applications最新文献

With the advancement of integrated circuit technology, the performance requirements for voltage reference circuits have become more demanding. Temperature coefficient (TC) and power supply rejection (PSR) are crucial parameters for evaluating their performance. To enhance the performance of TC and PSR over a wide temperature range, a piecewise temperature compensation voltage reference circuit has been designed and demonstrated. This voltage reference circuit is intended for motor driver chips and can operate under extreme temperature conditions. The compensation circuit utilizes a bipolar junction transistor to compensate for the reference voltage at low temperatures, while a MOSFET operating in the subthreshold region is employed to compensate for the reference voltage at high temperatures. Based on a 0.18 μm BCD (bipolar-CMOS-DMOS) technology, this design achieves an ultra-low TC of 6.6 ppm/°C from −40°C to 170°C, with a high PSR of −97 dB at 100 Hz. The effectiveness of the proposed circuit design has been validated.

This brief presents a modeling approach for a nonlinear series resistor–inductor–diode (RLD) circuit powered by either a direct or alternating voltage source—a configuration commonly encountered in power electronics and energy conversion systems. Due to the diode's nonlinear current–voltage characteristic and the inductor's dynamic response, the circuit is governed by a nonlinear differential equation. Because this equation lacks a closed-form analytical solution, a novel approximate solution is proposed by applying a g-function. This method enables accurate and robust computation across various operating conditions without relying on piecewise approximations or purely numerical solvers. The results are verified through MATLAB/SIMSCAPE simulations, demonstrating excellent agreement. Additionally, the MATLAB code is provided to support reproducibility and further research.

Stochastic computing (SC) is an emerging computing paradigm that offers excellent hardware efficiency and error tolerance. However, adopting SC in practical applications is not straightforward but faces serious challenges. In particular, a considerable overhead is imposed by the conversion between binary number and stochastic counterpart, which is usually performed by a stochastic number generator (SNG) and a binary counter. In this paper, we address this overhead issue by introducing a novel quantized SC architecture that shrinks the SNG hardware complexity significantly and a new approximate binary counter. To do this, we quantize binary numbers for SNGs to lower precision counterparts through several bit truncation schemes, which leads to an SNG overhead reduction. Also, we exploit a small-sized linear feedback shift register (LFSR) in the binary counter design to reduce its hardware resource consumption. When implemented in a 65-nm CMOS technology, the proposed quantized SNG and approximate binary counter reduce area and power by up to 68.3% and 80.6%, respectively, compared to the conventional full-precision SNG with an accurate counter. In addition, the proposed SC architecture with the LFSR-based counter does not deteriorate the stochastic computation accuracy beyond a certain degree of quantization. Besides, we demonstrate that the proposed SC schemes negligibly impact on processing quality with remarkably improved hardware efficiency by adopting it in a digital image processing application.

This paper proposes a standalone variable speed wind energy conversion system (VSWECS) with battery backup designed to fulfill the power requirements of small-scale educational or office buildings, traffic lighting, and so on. The system incorporates a drift avoidance-based perturb and observe (P&O) maximum power point tracking (MPPT) algorithm to harness maximum power from the VSWECS unit. A battery supports the load by absorbing or supplying power in case of excess and deficit wind power generation, respectively. The bidirectional DC-DC converter controls battery charging and discharging, utilizing a dual-loop proportional–integral (PI)-based controller. The proposed schemes are experimentally verified using a real-time digital controller. The results confirm that the scheme effectively meets load requirements, even with variations in wind speed and load, making the power generation unit self-sustainable and robust.

With the acceleration of urbanization, the energy consumption of residential communities is increasing. Therefore, researching feasible control strategies to address the frequent power fluctuations in these communities is of great significance. Energy router (ER), which offers advantages such as fast transmission efficiency, high energy utilization, and stable operation, is a key technology in future residential community systems. This paper first proposes a small-capacity energy router system suitable for residential communities. The system adopts a dual-energy storage solution consisting of a supercapacitor and a storage battery. In terms of control, the improved model predictive control (IMPC) method is adopted to combine PI control with model predictive control, and the fast stability characteristics of MPC and the low ripple characteristics of PI are used to achieve bus voltage stability. Then, the operating states of the energy router are divided into two modes and seven working states, aimed at stabilizing the bus voltage of the energy router and controlling the state of charge (SOC) of the storage battery. The analysis of the two operational modes of the energy router was finally conducted on the RT-LAB platform. The experimental results show that the proposed modular control method stabilizes the bus voltage effectively and ensures the longevity of the energy storage system, demonstrating robust overall stability.

SiC MOSFETs are widely used in AC/DC converters of electric vehicle. The Miller effect is an important cause of switching losses in SiC MOSFETs. This article focuses on all-silicon carbide three-phase voltage source rectifier (VSR) AC/DC converter. A series of studies have been conducted on the mechanism of SiC MOSFET losses and the causes of losses in the SiC three-phase VSR. Based on a detailed analysis of the switching process of SiC MOSFETs, a high-frequency switching model affected by Miller effect and device parasitic parameters is established. According to the model, the influence of various parameter changes on the Miller platform and switching losses under different driving modes is further discussed. A dual-pulse test platform is built to verify the correctness of the model and the rationality of the analysis. On this basis, a steady-state loss model of a three-phase VSR under space vector pulse width modulation (SVPWM) is established. Finally, a prototype of a three-phase VSR is designed and a test platform is built to experimentally verify the model. The output efficiency of the converter during closed-loop steady-state operation under multiple parameter changes is tested, and the experimental results are analyzed to provide suggestions for high-frequency SiC MOSFET drive design.