Transformerless High-Gain Three-Port Converter With Low Voltage Stress and Reduced Switches for Standalone PV Systems

Abstract

This paper proposes a high gain transformer-less three-port converter (TPC) for standalone photovoltaic (PV) systems. The TPC is designed and developed based on a dualinductor high gain two-port converter by utilizing one of the buffer capacitors to derive the third part for PV input. A hybrid pulse frequency modulation (PFM) scheme unified with a pulse width modulation (PWM) control strategy is adopted, which realizes the maximum power point tracking (MPPT) control, load voltage regulation, and bidirectional energy flow at the battery port. The proposed TPC offers the unique advantages of high voltage gain, continuous battery port current, reduced power semiconductors, lower voltage stresses, the common ground shared by all ports, low-cost gate driver, and small size of the rear-end inductor. The working principle, steady-state characteristics, small signal models and control method, including design conditions, are comprehensively analyzed. The correctness of the theoretical analysis is verified by developing a 300W experimental prototype, which shows the maximum efficiency is 97.7%.

Semiconductor-Based 650nm Class I Laser Eye Protector

“…The HX70A series is a three-port low voltage detector [7] realized by applying CMOS technology, which can detect fixed voltages ranging from 2.2V to 7V. The detector comprises four parts: a high-precision and low-power standard voltage source, a comparator, a hysteresis circuit, and an output driver.…”

Review on Non-Isolated Multiport Converters for Residential DC Microgrids

“…However, conduction losses cannot be easily limited, as the increase of switching frequency and the resulting high voltage levels and overshoots necessitate the selection of devices with a higher voltage rating, and consequently, higher conduction resistance. [22,23,24,25,26,27,28,29,30,31,32,33,34,35]. over half the UP-NI-MPCs studied utilize soft-switching techniques for increased efficiency.…”

“…Therefore, by interfacing another input source, they can be employed to extract novel multiport topologies. The TPC of [30] (Figure 8) utilizes two inductors without a multiplier cell and, therefore, its gain is limited to double the gain of the conventional boost converter. Nevertheless, it shows high efficiency, low component count and continuous battery current.…”

“…First, it is possible to connect the RES and ESS ports in series [27], which can result in reduced gain if one source fails. Second, multiple RES may be connected in series [29,30], which requires considering the impact of RES module mismatch, shading, and hotspot bypassing (in the case of PVs) [44], regarding power generation and converter gain.…”

Analysis, design, and reliability evaluation of a modified multi‐port quasi‐resonant converter with high gain

“…The discontinuous input current and narrow voltage gain are the limitations related to the above multi‐port converter. A multi‐port converter's high step‐up ability with continuous input current, and bidirectional energy storage system for input port are the most important features described in article [17]. In reference [18], a three‐input converter hybridizing the PV panel, fuel cell, and a wind turbine with system power management is implemented.…”