Effect Of Equivalent Series Resistance Research Articles

Performance Analysis of a Positive Output Voltage Dual Input DC–DC Converter for Hybrid Energy Application

Renewable energy sources and storage devices are combined as a hybrid energy system to provide reliable electricity to the load. Naturally, such sources have distinct voltage–current characteristics. In this paper, a dual input positive output voltage DC–DC converter is used as power electronic interface for integration of the above nature of sources. Different modes of operation of the above converter such as buck, boost and buck–boost are discussed with necessary circuit and equations. A detailed current and voltage stress analysis of various switching devices available in the converter is also discussed. This analysis helps to select the switching devices in an optimized and cost-effective manner. The effect of equivalent series resistance of such storage elements on the output voltage is investigated in detail. The MATLAB simulation of the power converter is carried out, and a prototype of the converter is also fabricated. A power control strategy is proposed for the power converter with the objective of voltage regulation during the load side and source side disturbances. Different experimental analyses of the fabricated converter in the laboratory environment have been conducted, and the test results are presented in this paper.

Estimation of Curve Tracing Time in Supercapacitor based PV Characterization

Smooth and noise-free characterisation of photovoltaic (PV) generators have been revisited with renewed interest in view of large size PV arrays making inroads into the urban sector of major developing countries. Such practice has recently been observed to be confronted by the use of a suitable data acquisition system and also the lack of a supporting theoretical analysis to justify the accuracy of curve tracing. However, the use of a selected bank of supercapacitors can mitigate the said problems to a large extent. Assuming a piecewise linear analysis of the V–I characteristics of a PV generator, an accurate analysis of curve plotting time has been possible. The analysis has been extended to consider the effect of equivalent series resistance of the supercapacitor leading to increased accuracy (90–95%) of curve plotting times.

Structure for multi‐input multi‐output dc–dc boost converter

In this study, a new structure for multi-input multi-output (MIMO) dc-dc boost converter is proposed. The number of inputs and outputs of the converter are arbitrary and independent from each other. The proposed topology has the advantages of both dc-dc boost and switched-capacitor converters. This converter is proper to use in applications like photovoltaic or fuel cell systems. The main advantages of the proposed structure are possibility of using energy supplies with different voltage-current characteristics, continuous input current, high voltage gain without high duty cycle, and possibility of performing at high switching frequencies. First, the different operating modes of the proposed converter are explained. Then, the effect of equivalent series resistance (ESR) of the inductor and voltage drop of diodes and switches on the voltage gain is investigated. Finally, the correctness operation of the proposed converter is reconfirmed by the simulation and experimental results.

SM-based IMC-PID Control of Single-switch Quadratic Boost Converter for Wide DC Conversion Ratios

This article presents a sliding-mode (SM) based internal model control-proportional-integral-derivative (IMC-PID) controller that combines the concepts of IMC-PID and SM control for a quadratic boost converter. The effect of equivalent series resistance of capacitors and inductors is considered in this model. The control scheme is based on sensing the inductor current and its subsequent use as feedback. An internal SM control loop forces the converter inductor current to follow the reference established by IMC-PID control. The effectiveness of the proposed control scheme is verified by comparing it with the existing control technique. This article presents detailed simulation analysis and experimental validation on a prototype quadratic boost converter. The simulation and experimental results clearly demonstrate the superior dynamic performance when subjected to line variation, load variation, and reference voltage tracking.

Pulse-Train-Controlled CCM Buck Converter With Small ESR Output-Capacitor

The pulse-train (PT) control technique for switching dc-dc converters is simple to design and benefits from excellent control performance. Up to now, almost all of the works on PT control are focused on switching dc-dc converters operating in discontinuous conduction mode, with few works reported on PT control of switching dc-dc converters operating in continuous conduction mode (CCM). In this paper, a PT-controlled CCM buck converter is studied and a unique low-frequency oscillation phenomenon is revealed, which results in large undesired inductor-current and output-voltage variations. The effect of equivalent series resistance (ESR) output-capacitor on the low-frequency oscillation is examined. The results indicate that such oscillation occurs when the ESR output-capacitor is relatively small and disappears when it is relatively large. However, a larger ESR will result in a large output-voltage ripple. In order to avoid the low-frequency oscillation and, at the same time, to ensure a small output-voltage ripple, the ICRIF circuit is applied. In this way, a small ESR output-capacitor can be used to decrease the output-voltage ripple. Simulation and experimental results are provided to verify the theoretical analysis.

Analysis of Pulse Bursting Phenomenon in Constant-On-Time-Controlled Buck Converter

In this paper, the effect of equivalent series resistance (ESR) of an output capacitor on the performance of a constant-on-time (COT)-controlled buck converter is studied, and a pulse bursting phenomenon is revealed. It indicates that the ESR of the output capacitor is one of the key factors causing pulse bursting phenomenon in COT-controlled buck converters, and the critical ESR is derived via time-domain analysis and stability analysis in the s-domain. It is pointed out that, when the ESR of the output capacitor is smaller than the critical ESR, pulse bursting phenomenon occurs; otherwise, it disappears. Simulation and experimental results are provided to verify the theoretical analysis results.