Explore the vast range of titles available.

In this paper, partial energy processing is applied to the current sharing technique for multiphase LLC resonant converters. The proposed circuit consists of an LLC resonant converter and a flyback converter, where the flyback converter is only used for partial energy processing. The input voltage of the LLC resonant converter is fine-tuned by the flyback converter to solve the problem of a voltage gain difference between the two phases of the LLC resonant converter caused by the error of the resonant tank components, which prevents the output current from being nonequalized. Since the compensation power is much smaller than the output power, and only one phase will be during circuit operation, the impact on the overall efficiency is minimal. Due to the low dependence between the LLC resonant converter and the flyback converter, they are operated at different switching frequencies. In addition, due to the low dependence between each phase, the circuit can be expanded using odd and even phases.

Both electric vehicles and Tokamak power supply use multiple parallel converters to realize high current operation in four quadrants. A finite‐time current sharing control algorithm based on disturbance compensation is proposed to improve the converter system's dynamic and steady‐state performance so that the system can achieve the required load current and branch‐current sharing in a finite time. In the proposed algorithm, this paper adopts a finite‐time observer for unknown disturbances in the converter system and load circuit due to disturbances, such as unknown inductance and resistance in the converter system. The results show that the load current control overshoot is minimal, and the dynamic performance of each branch current is higher than the traditional control algorithm. A finite‐time current sharing control algorithm based on disturbance compensation is proposed so that the converter system can achieve the required load current and branch current sharing in a finite time.

Microgrid technology is poised to transform the electricity industry. In the context of commercial/domestic buildings and data centers, where most loads are native direct current, DC microgrids are in fact a natural choice. Voltage stability and current/power‐sharing between sources within a DC microgrid have been studied extensively in recent years. DC voltage droop control is known to have its drawbacks in that current or power‐sharing is relatively poor. To eliminate this drawback, some have proposed to add a communication‐based consensus control in addition to the primary voltage droop control loop. The current sharing performance is improved, however, the voltage deviation inherent in droop control requires a further, slower control to achieve voltage quality control. To overcome this complication, and reduction in response time, a low latency communication‐based control technique that achieves proportional current sharing without significant voltage deviations is proposed in this work. The stability of the proposed control technique is compared to state‐of‐the‐art using eigenvalue and transient analyses. The negative impact of communication delays on proposed control is discussed in detail.

Planar transformers have been widely used in isolated power supplies. However, with a large current density, the parallel windings usually cannot share the current evenly. This uneven current-sharing may cause additional winding losses, and damage the performance of the power converter. In this paper, a novel central-tapped planar transformer structure is proposed. Regardless of whether it is in the first half cycle or the second half cycle, the proposed twelve-layer transformer can be simplified as four three-layer transformers connected in parallel. Moreover, there is a “shielding layer” between adjacent three-layer transformers. In addition, the proposed transformer structure is optimized with a symmetrical layer arrangement, and the skin effect and proximity effect can be further reduced. Simulation and experimental tests indicate that the optimized planar transformer can stably provide 476.1 W of output power at a frequency of 1.25 MHz. The peak efficiency of the optimized transformer is up to 99.2%, and there is no obvious hot spot on the PCB board. It is noteworthy that the temperature difference in the secondary windings is less than 5 °C, which means the current-sharing in the secondary windings works well.

Multi-chip parallel power modules are highly favored in applications requiring high capacity and high switching frequency. However, the dynamic current imbalance between parallel chips caused by asymmetric layouts limits the available capacity. This paper presents a method to optimize dynamic current distribution by adjusting the lengths and connection points of bond wires. For the first time, a response surface model and nonlinear constraint optimization algorithm are introduced, along with parameter analysis based on finite element methods, to establish the response surface models for the parasitic inductance of bond wires and DBC (direct bonded copper). By leveraging the optimization goals for parasitic inductance and the analytical expressions of all response surfaces, the dynamic current sharing issue was transformed into a nonlinear constrained optimization problem. The solution to this optimization problem identified the optimal connection points for the bond wires, enhancing dynamic current sharing performance. Simulations and experiments were conducted, revealing that the optimized automotive-grade module exhibited a significant reduction in current differences between parallel branches, from 41.7% to 5.03% compared with the original design. This indicated that the proposed optimization scheme for adjusting bond wire connection points could significantly mitigate current disparities, thereby markedly improving current distribution uniformity.

In DC microgrids, if the oscillatory current is not shared among DGs, it may cause unallowable voltage distortion and overcurrent. In this paper, a distributed cooperative control scheme is introduced for DC microgrids in order to effectively share both the DC and the oscillatory components of current among DC sources. The hierarchical control method comprises four primary controllers namely voltage controller, conventional droop, oscillatory current droop and virtual conductance units, and three secondary controller units based on cooperative control principles. The primary controllers on each DG unit only use DGs' local information, while secondary controllers also require information of other DG units. In the secondary control part, firstly, via using the cooperative control, the DC current‐sharing becomes accurate. Then, a novel droopbased oscillatory current‐sharing controller unit is proposed in which by using the consensus method the error of oscillatory current‐sharing is significantly reduced. A voltage observer, based on cooperative control is employed to compensate the inevitable voltage drop in DC microgrid, caused by droop controller. The voltage oscillation caused by oscillatory current‐sharing unit is decreased through implementation of a virtual conductance signal applied to the inner current controller. The presented method is validated by a simulation with several cases.

A new magnetic integrated parallel current sharing control method for parallel silicon carbide (SiC) power devices is presented in this article. The problem of the application of parallel connected SiC power devices is analyzed. The coupled inductance method is adopted to solve the problem. Based on the active-back converter, we establish the theoretical model of the coupled inductance, and figure out its working mechanism. The integrated magnetic device is designed based on the working mechanism, and the effectiveness is determined through simulation. A 12 V/10 A output magnetic integrated active-flyback converter prototype is fabricated and tested to verify the strategy. Measurement results show that, with the proposed magnetic integrated method, the mismatch voltage is suppressed to 0.1 V under all load conditions, and the efficiency increases by at most 6.52% under full load conditions.

When the power supply of superconducting magnet for Comprehensive Research Facility for Fusion Technology (CRAFT) is operating under short circuit condition and overload, the commutation overlap angle changes dynamically, which greatly increases the complexity in the system modeling and the difficulty in control. To solve these problems, by replacing the circular arc with small bowstring, the dynamic mathematical model under short-circuit operation can be simplified. In order to precisely adjust the impact speed and amplitude of impulse current under short circuit operation, an open-loop control strategy is proposed based on dynamic mathematical model, which can get the excellent performances, inherent stability, fast response and no overshoot. The instantaneous current sharing control strategy using virtual impedance is designed to solve the problem of serious overload and dynamic current sharing under short circuit operation, which thereby ensures the overall overload capacity of superconducting magnet power supply. At last, simulations and experiments are conducted, and results validate the feasibility of the proposed methods.

This paper proposes a novel decoupling control scheme for input-parallel modular dual active bridge (DAB) DC–DC converters, where the input current sharing (ICS) control loops and output voltage regulation (OVR) control loop are completely decoupled. First, the input-parallel output-parallel and input-parallel output series systems of modular DAB converters are modeled based on the small-signal modelling of a DAB module. In general, coupling effects between the ICS and OVR control loops exist when the input currents and output voltage are employed as control variables. To eliminate this undesirable effect, the input current errors of DAB converters are introduced as new control variables. In this way, independent single-input single-output systems are obtained. Consequently, a uniform power distribution among all of the DAB modules is achieved in the transient state as well as the steady state, even in the case of parameter mismatch. The feasibility of the proposed control scheme has been verified by simulation and experimental results.

A digital current sharing control method leveraging a CAN bus is developed to inhibit the fluctuating current distributions of parallel converters in high-output oxidation power systems. When compared to conventional current sharing strategies, the proposed design significantly reduces circuit complexity without resorting to an analog current sharing bus, and is extremely robust in maintaining system functionality against one or multiple module failures. The digital control design also features anti-interference among high-power switching converters. In addition to detailing the operation principles and mathematical deductions of the state-space average model, the design of a current sharing controller and a current sharing scheme based on a CAN bus are presented to analyze the steady-state operation of parallel converters and dynamic-state operation. Based on these observations, a proof-of-concept prototype was developed that offers a maximum output power of nearly 400 kW with a current sharing error (CSE) below 2.1%. In addition, this system features outstanding anti-interference capability in intense electromagnetic fields.