Multiple-Loop Control Design for a Single-Stage PV-Fed Grid-Tied Differential Boost Inverter

Abstract

This paper focuses on the control design of a differential boost inverter when used in single-stage grid-tied PV systems. The inverter performs both Maximum Power Point Tracking (MPPT) at the DC side and Power Factor Correction at the AC side. At first, the state-space time-domain averaged model of the inverter is derived and the small signal frequency domain model is obtained using a quasi-static approximation in which the inverter is treated as a DC–DC converter with a slowly varying output voltage. Then, the controllers are designed using a three-loop strategy in which the inverter inductor currents loop is used for suitable compensation, the DC Photovoltaic (PV) voltage loop is used for MPPT and the output grid current loop is used for Power Factor Correction (PFC) and active power control. The selection of the control parameters is based on a compromise among suitable system performances such as settling time of the input PV voltage, the sampling period of the MPPT, total harmonic distortion of the output grid current, power factor as well as suppression of subharmonic oscillation for all the range of the operating duty cycle. The resulting design ensures that the oscillations of the voltage, current and power at the DC side and the grid current at the AC side are effectively controlled. The validity of the proposed control design is verified by numerical simulations performed on the switched model of the system demonstrating its robustness and fast response under irradiance variations and MPPT perturbations despite the nonlinearity and complexity of the system.

Fast-Scale Instability and Stabilization by Adaptive Slope Compensation of a PV-Fed Differential Boost Inverter

“…The Q and Q outputs of the flip-flop are the driving pulses for the switches Q 1 -Q 4 as shown in Figure 1. A type-III controller was demonstrated to be effective for controlling the grid current in the system [10]. Its transfer function in the Laplace s-domain can be expressed as follows [28]:…”

“…The differential boost inverter has been introduced in [6] and since then many studies have dealt with its control design [6][7][8][9][10]. In most of the studies, inverters with a constant input voltage and an ohmic resistance as a load have been considered and their control design has been accordingly tackled.…”

“…In most of the studies, inverters with a constant input voltage and an ohmic resistance as a load have been considered and their control design has been accordingly tackled. In [7,10,11], a grid-connected boost inverter has been considered and its control design has been addressed.…”

Design and implementation of bi-directional converter with internet of things control based reading

“…In the blackouts case, the design operates as the current-fed full-bridge converter to boost the power from a 48-V battery (44 -56) V input voltage to the 380 V DC bus to support the load backup. The variation during the operation period must guarantee the continuity of power to the load [11]. The system response of about 200 µs, which significantly reduces the DC bus capacitors, is required to maintain the voltage at an acceptable level during the operation period.…”

Analysis of Subharmonic Oscillation and Slope Compensation for a Differential Boost Inverter

“…Since its introduction in [47], many studies have dealt with the control design of the differential boost inverter using different approaches and strategies [44,45,[47][48][49]. The focus in most of the works published about this inverter is on the control design.…”