Design and Realization of a Digital PV Simulator with a Push-Pull Forward Circuit

Abstract

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with k i and R L as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of R L and the operating point of the PV simulator to match the controller parameters with R L . The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

Design of a Low-Cost PV Emulator Applied for PVECS

“…Several control strategies, which affect the PV accuracy, transient response, and steady state response and connect the PV model to the power stage, were used to determine and locate the PV emulator operating point as the real PV module I = f(V) curve. In References [11][12][13], authors used the direct referencing method as a common and simple control method that exploit the PI regulator and power converter dynamic characteristics to find the operating point. However, the wrong sizing of external factors and parameters as well as their dependence cause significant oscillations at the emulator output.…”

Simple and Low-Cost Photovoltaic Module Emulator

“…In [24] is proposed a solution that adopts modular hardware, configurable software, systematic modeling, and design methods, requiring a PC running Matlab/Simulink to determine the controller parameters.…”

Proton Exchange Membrane Fuel Cell Emulator Using PI Controlled Buck Converter

“…For designing PV model most literatures use either single diode PV model or look up [2]. Other than buck converters, buck-boost, boost, and push-pull converters are also used for PV emulator implementation [3]- [5]. However, the control strategy becomes complex in case of other converters.…”

“…However, the control strategy becomes complex in case of other converters. Recent works in control strategy development includes using fuzzy-PI controller to determine the operating point [5] and microcontroller based implementation [6]. Wind turbine emulator (WTE) consists of two mechanically connected drives: one works as a motor and another as a generator.…”