-Constant power loads (CPLs) may yield instability due to the well-known negative impedance characteristic. This study analyzes the factors which cause instability of a DC microgrid with multiple DC-DC converters. Two stabilization methods are presented for two operation modes: constant voltage source mode and droop mode. And sufficient conditions for the stability of the DC microgrid are obtai...

This paper presents a novel control method to improve the efficiency of low-voltage DC-DC converters at light loads. Pulse Width Modulation (PWM) converters have poor efficiencies at light loads, while pulse frequency modulation (PFM) control is more efficient for the same cases. Switching losses constitute a major portion of the total power loss at light loads. To decrease the switching losses...

DC grids are prone to small-signal instabilities due to the presence of tightly controlled loads trying to keep the power consumption constant over range of terminal voltage variations. Th, so-called, constant power load (CPL) represents a classical example of this destabilizing behavior acting as an incremental negative resistance. Real-life DC loads represented by controlled power converters ...

The aim of this paper is to design a nonlinear model predictive control for DC-DC buck converters to track constant reference signals with zero steady-state error. The online trained neural network (NN) model is employed as the predictor and the steady-state error, which is called the offset, is studied in the presence of the changes in system parameters and the external disturbances. The stabi...

Solar energy is among the abundant forms of energy, it very important to make best use it. But intermittent nature solar makes PV generation unreliable at times. The a battery as an storage device can help mitigate this problem some extent. A Bidirectional DC-DC converter must be used connect DC link in order maintain steady voltage. then connected load. In paper, P&O MPPT technique get max...

Constant power loads have negative impedance characteristics, which reduce the damping of DC/DC converter systems and effects on stability DC microgrid. In this paper, a finite-time parameter observer-based sliding mode controller is proposed for boost with constant loads. Firstly, non-singular terminal sliding-mode designed based flatness differential control theory. Secondly, observer to esti...

the application of ion current signals is one of the most recent approaches in engine management systems. by applying a small constant dc voltage across the electrodes of the spark plug and measuring the current through the electrode gap, the state of gas may be measured and investigated. in this paper a computer code is developed in order to analyze the state of gas during the combustion perio...

The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC) is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submod...