Review of PV Generator as an Input Source for Power Electronic Converters

This paper presents a novel soft-switching boost DC-DC converter, which uses an edge-resonant switch capacitor based on the pulse width modulation PWM technique. These converters have high gain voltage due to coupled inductors, which work as a transformer, while the boost converter works as a resonant inductor. Upon turning on, the studied soft switching circuit works at zero-current soft switching (ZCS), and upon turning off, it works at zero-voltage soft switching (ZVS) while using active semiconductor switches. High efficiency and low losses are obtained while using soft switching and auxiliary edge resonance to get a high step-up voltage ratio. A prototype model is implemented in the Power Electronics Laboratory, Assiut University, Egypt. Seventy-two-panel PV modules of 250 W each were used to simulate and execute the setup to examine the proposed boost converter.Energies 2020, 13, 749 2 of 17 achieved by adding an auxiliary circuit, as shown in Figure 1a, instead of a classical hard-switched converter [6]. Moreover, the auxiliary circuit has no additional complexity or cost.To reduce the weight and size, a higher switching frequency operation, i.e., in the range of more than 50 kHz, is utilized [7]. In traditional switching converters, the exemplary switching frequency is between 5 kHz and 20 kHz. The switching frequency generally cannot be increased because this results in increasing switching losses and stresses on semiconductor devices. A high frequency is utilized to reduce the volume and weight of passive devices. The dynamic performance is better in the case of higher frequencies. High-frequency switching speeds up the converter response time and reduces the output filter volume, cost, and size. A high switching frequency is desirable for the minimum output inductor size and maximum control loop bandwidth. Overall system size will be reduced due to the operation of switches at a high frequency, which will make the new converters more feasible.To overcome these problems, soft-switching schemes such as zero-voltage soft switching (ZVS) type or zero-current soft switching (ZCS) commutation should be utilized to reduce switching losses and the semiconductor device stresses. For power converters in a distributed PV system, a soft-switching technique is proposed [8][9][10][11][12]. The presented converter (see Figure 1b) has advantages of improved efficiency at a higher switching frequency, low leakage current, wide load range, reduced weight and size, and a maximum total efficiency of 97.1% at a switching frequency of 100 kHz.The problems of excessive electromagnetic interference EMI and low efficiency can be solved by using zero-voltage-transition (ZVT) converters by limiting the turning-off di/dt in the output-side rectifier. Various types of ZVT converters have been presented before [9,13], but these converters suffer from several drawbacks, such as the following.

Section: Circuit Of Controlmentioning

confidence: 99%

Section: Circuit Of Controlmentioning

confidence: 99%

Section: Circuit Of Controlmentioning

confidence: 99%

See 1 more Smart Citation

Novel Soft-Switching Integrated Boost DC-DC Converter for PV Power System

Sayed

Gronfula²,

Ziedan

2020

“…However, PV current harmonics also depend on the PV series-equivalent resistance R PV , that is a function of the operating point on the PV field characteristic. Considering a PV plant of a few kW (single-phase), R PV ranges between a few Ω near the open-circuit point, passing to around a few tens of Ω near the MPP and up to hundreds or even thousands of Ω toward the short-circuit point [26]. These considerations can be readily exploited to design the dc-link capacitor C H in order to obtain PV voltage and current harmonics amplitude in the order of a few percent compared to the rated MPP values.…”

Section: Pv Current Harmonicsmentioning

confidence: 99%

A Single-Phase Multilevel PV Generation System with an Improved Ripple Correlation Control MPPT Algorithm

Hammami

Grandi

2017

Abstract:The implementation of maximum power point tracking (MPPT) schemes by the ripple correlation control (RCC) algorithm is presented in this paper. A reference is made to single-phase single-stage multilevel photovoltaic (PV) generation systems, when the inverter input variables (PV voltage and PV current) have multiple low-frequency (ripple) harmonics. The harmonic analysis is carried out with reference to a multilevel configuration consisting of an H-bridge inverter and level doubling network (LDN) cell, leading to the multilevel inverter having double the output voltage levels as compared to the basic H-bridge inverter topology (i.e., five levels vs. three levels). The LDN cell is basically a half-bridge fed by a floating capacitor, with self-balancing voltage capability. The multilevel configuration introduces additional PV voltage and current low-frequency harmonics, perturbing the basic implementation of the RCC scheme (based on the second harmonic component), leading to malfunctioning. The proposed RCC algorithm employs the PV current and voltage harmonics at a specific frequency for the estimation of the voltage derivative of power dP/dV (or dI/dV), driving the PV operating point toward the maximum power point (MPP) in a faster and more precise manner. The steady-state and transient performances of the proposed RCC-MPPT schemes have been preliminarily tested and compared using MATLAB/Simulink. Results have been verified by experimental tests considering the whole multilevel PV generation system, including real PV modules, multilevel insulated-gate bipolar transistor (IGBT) inverters, and utility grids.

“…It is worth mentioning that there are effects of the behavior of the small-signal resistance of the PV generator on the connected power electronics converters as discussed in [38]. It was also noticed earlier that certain commercial emulators may contain resonances, which may lead to unstable operation of the interfacing converter as discussed in [39].…”

Section: Experimental Setup For Testing Pv Inverter and Mppt Algorithmsmentioning

confidence: 99%

An Emulated PV Source Based on an Unilluminated Solar Panel and DC Power Supply

Zhou

Macaulay

2017

This paper provides a review on various PV simulator technologies as well as presents a novel equivalent photovoltaic (PV) source that was constructed by using un-illuminated solar panels and a DC power supply that operates in current source mode. The constructed PV source was used for testing photovoltaic converters and various maximum power point tracking (MPPT) algorithms required for capturing the maximum possible output power. The mathematical model and electrical characteristics of the constructed PV source were defined and analyzed in detail in the paper. The constructed PV source has the advantages of high bandwidth over the switching circuit based PV simulators. The constructed PV source has been used for testing various power electronics converters and various control techniques effectively in laboratory environments for researchers and university students.