Active power decoupling methods are developed to deal with the inherent ripple power at twice the grid frequency in single-phase systems generally by adding active switches and energy storage units. They have obtained a wide range of applications, such as photovoltaic (PV) systems, light-emitting diodes (LEDs) drivers, fuel cell (FC) power systems, and electric vehicle (EV) battery chargers, etc. This paper provides a comprehensive review of active power decoupling circuit topologies. They are categorized into two groups in terms of the structure characteristics: independent and dependent decoupling circuit topologies. The former operates independently with the original converter, and the latter, however, shares the power semiconductor devices with the original converter partially and even completely. The development laws for the active power decoupling topologies are revealed from the view of “duality principle,” “switches sharing,” and “differential connection.” In addition, the exceptions and special cases are also briefly introduced. This paper is targeted to help researchers, engineers, and designers to construct some new decoupling circuit topologies and properly select existing ones according to the specific application.

Review of Active Power Decoupling Topologies in Single-Phase Systems

Parameter extraction of solar photovoltaic models using an improved whale optimization algorithm

Comprehensive overview of meta-heuristic algorithm applications on PV cell parameter identification

This paper proposes a new converter for photovoltaic (PV) water pumping or treatment systems without the use of chemical storage elements, such as batteries. The converter is designed to drive a three-phase induction motor directly from PV energy. The use of a three-phase induction motor presents a better solution to the commercial dc motor water pumping system. The development is oriented to achieve a more efficient, reliable, maintenance-free, and cheaper solution than the standard ones that use dc motors or low-voltage synchronous motors. The developed system is based on a current-fed multiresonant converter also known as resonant two-inductor boost converter (TIBC) and a full-bridge three-phase voltage source inverter (VSI). The classic topology of the TIBC has features like high voltage gain and low input current ripple. In this paper, it is further improved with the use of a nonisolated recovery snubber along with a hysteresis controller and the use of a constant duty cycle control to improve its efficiency. Experimental results show a peak efficiency of 91% at a rated power of 210 W for the dc/dc converter plus the three-phase VSI and a peak efficiency of 93.64% just for the dc/dc converter. The system is expected to have a high lifetime due to the inexistence of electrolytic capacitors, and the total cost of the converter is below 0.43 U$/Wp. As a result, the system is a promising solution to be used in isolated locations and to deliver water to poor communities.

Implementation of a High-Efficiency, High-Lifetime, and Low-Cost Converter for an Autonomous Photovoltaic Water Pumping System

Power electronic converter (PEC)-interfaced renewable energy generators (REGs) are increasingly being integrated to the power grid. With the high renewable power penetration levels, one of the key power system parameters, namely reactive power, is affected, provoking steady-state voltage and dynamic/transient stability issues. Therefore, it is imperative to maintain and manage adequate reactive power reserve to ensure a stable and reliable power grid. This paper presents a comprehensive literature review on the reactive power management in renewable rich power grids. Reactive power requirements stipulated in different grid codes for REGs are summarized to assess their adequacy for future network requirements. The PEC-interfaced REGs are discussed with a special emphasis on their reactive power compensation capability and control schemes. Along with REGs, conventional reactive power support devices (e.g., capacitor banks) and PEC-interfaced reactive power support devices (e.g., static synchronous compensators) play an indispensable role in the reactive power management of renewable rich power grids, and thus their reactive power control capabilities and limitations are thoroughly reviewed in this paper. Then, various reactive power control strategies are reviewed with a special emphasis on their advantages/disadvantages. Reactive power coordination between support devices and their optimal capacity are vital for an efficient and stable management of the power grid. Accordingly, the prominent reactive power coordination and optimization algorithms are critically examined and discussed in this paper. Finally, the key issues pertinent to the reactive power management in renewable rich power grids are enlisted with some important technical recommendations for the power industry, policymakers, and academic researchers.

Reactive Power Management in Renewable Rich Power Grids: A Review of Grid-Codes, Renewable Generators, Support Devices, Control Strategies and Optimization Algorithms

This paper presents an approach that allows to apply space-vector modulation strategy to eliminate common-mode voltage in multilevel inverters. The strategy is based on the reduction of the space vector diagram and on the choice of switching states in which the common-mode voltage is zero. Results were obtained with a real-time simulator and an experimental platform of a cascaded inverter up to 11-level shows its effectiveness. The influence of dead-time over the algorithm performance is investigated too.

A fast space-vector algorithm for common-mode voltage elimination in multilevel converters

This work proposes a technique to reduce the low frequency DC-link energy oscillation due to the pulsating single-phase energy flow in a single-phase to single-phase Voltage Source Converter (VSC) and Current Source Converter (CSC) which operate connected to the grid That pulsating energy is the major responsible for increasing the size of the passive components and power losses in the converter The pulsation reduction is achieved by incorporating two auxiliar active switches and one passive energy storage element to the rectifier and inverter side Additionally, this paper presents the comparison of these convertes regarding efficiency and power density Details control strategy is presented Simulation and experimental results are provided to validate the theoretical approach

Compensation of DC-link oscillation in single-phase to single-phase VSC/CSC and power density comparison

This paper proposes a shunt active power filter (SAPF) composed of four H-bridge converters. Each of them is connected by means of isolation transformers. Compared to conventional topologies, the proposed converter permits reducing: dc-link voltage rating, grid current harmonic distortion and/or switching frequency (switching losses). A suitable control strategy to adjust the filter currents as well as dc-link voltage are presented. Two PWM strategies are designed to command the converter according to the reference voltage provided by the controllers. Simulation and experimental results are presented in order to validate theoretical approaches.

Four H-bridge based shunt active power filter for three-phase four wire system

This paper investigates the performance of adjustable-speed drive systems for capacitor-start or capacitor-run single-phase motors. It is demonstrated that operating single-phase motors in two-phase mode contributes to increase the motor torque, reduces the torque pulsation and provides smooth start-up currents, this paper reveal how the gain in performance occur depending on the kind of motor. Also a high performance control strategy based on indirect rotor field orientation is presented. Simulation and experimental results are provided to demonstrate the performance, correctness and feasibility of the proposed approaches.

Motor Drive System For Single-phase Induction Motors - An Evaluation

In this work it is presented a two-phase open-end winding induction motor (IM) driven by an improved current source inverter (CSI). The proposed inverter has independent full quadrant operation, lower DC-link current value, high magnetics power density, 25% more efficient and high AC output voltage waveform quality compared to conventional CSI solutions. A back-to-back AC-DC-AC current source converter is used to drive the two-phase open-end winding IM, where in the AC-DC portion it is used a conventional three-phase three-leg rectifier, and the proposed two-phase inverter is used in the DC-AC portion. The two-phase IM model is also presented. Two motor drive methods for the improved CSI are used: Volts/Hertz and modified q-axis indirect flux oriented control. Simulation and experimental results are provided in order to validate the theoretical approach.

Mauricio B. R. Correa

Papers

A fast space-vector algorithm for common-mode voltage elimination in multilevel converters

Compensation of DC-link oscillation in single-phase to single-phase VSC/CSC and power density comparison

Four H-bridge based shunt active power filter for three-phase four wire system

Motor Drive System For Single-phase Induction Motors - An Evaluation

Two-phase open-end winding induction motor drive using improved current source inverter