A Frequency Adaptive PIMR-Type Repetitive Control for a Grid-Tied Inverter

Grid background and dead-time harmonic perturbations pose challenges in maintaining power quality and stability in the grid integration of renewable energy conversion systems. Therefore, a super-twisting algorithm with the ability to reject harmonic perturbations on three-phase grid-tied inverters is proposed. The algorithm design is related to dead-time and grid background harmonics so that robust performance is achieved under these perturbations. To highlight the advantages of the proposed algorithm, it is compared against proportional-integral (PI) control in several dead-time and grid background harmonic sweeps. The maximum inverter current distortion obtained with PI control in simulation is 15.53%. However, by using the proposed algorithm instead, the maximum current distortion is reduced to 1.8%. Dead-time is experimentally swept by using a permanent magnet motor as a harmonic-free grid. Experimental results of grid background harmonics are obtained by injecting reactive energy into a grid with 2.19% voltage distortion. When PI control is used in the experimental setup, the maximum inverter current distortion obtained is 11.4%. However, with the proposed algorithm, the maximum current distortion is reduced to 1.5%, which complies with the standard IEEE 1547-2018. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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“…Finally, by adding Equations (26) to (28), the gain k 2 is obtained. The value of k 2 is given in Appendix A.…”

Section: Gain Kmentioning

confidence: 99%

Inverter harmonic perturbations rejection in renewable energy conversion systems applying a super‐twisting algorithm

Memije

Carranza

Rodriguez

et al. 2021

IET Renewable Power Gen

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“…The fast penetration of RES, such as Photovoltaics (PVs), increases the popularity of DC-AC power converters at gridconnected applications [1][2][3][4][5]. However, the new PV architectures have independent PV modules with low input voltages [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Single-Stage Three-Phase Grid-Tied Isolated SEPIC-Based Differential Inverter With Improved Control and Selective Harmonic Compensation

2020

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The simple circuit based on DC-DC converters is the main attractive feature of the differential inverter topologies. It has a single-stage and provides modularity and scalability. However, the Negative Sequence Harmonic Component (NSHC) generated at the output terminal may hinder its practical applications. This paper presents a single-stage three-phase isolated differential inverter based on three High-Frequency Link (HFL) transformer-based DC-DC SEPIC converters. The utilized SEPIC converters perform voltage step-up/ down capability with galvanic isolation, which is essential for Renewable Energy Sources (RES). It mitigates the Common-Mode Voltage (CMV) and ElectroMagnetic Interference (EMI). Moreover, this paper proposes a two-loop based d-q synchronous frame grid-current control to mitigate its NSHC. A Type-II compensator and simple NSHC detection circuit are proposed to enhance the inverter's stability and compensate phase-delay of the utilized SEPIC converters. NSHC detection is developed using three cascaded Low Path Filters (LPFs). A 1.6kW inverter prototype was set to validate the performance of the proposed inverter and its control. The control is implemented by the MWPE3 C6713A Expert III DSP board. The proposed topology has a maximum efficiency of 89.744 at 700W output power and 86.4% at full power. The proposed control decreases the NSHC from 40.6 % to 1.614%, which shows its accuracy and precision. Furthermore, THD is reduced from 35.61% to 4.087% and satisfy the recent grid codes (<5%). The simulation results using PSIM software, power loss distribution, and a comparison study of the proposed inverter with similar topologies are also presented.

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“…This approach is realized by approximating the fractional delay with the Lagrange interpolating polynomial for the RC harmonic controller. A similar frequency-adaptive scheme based on the RC with an improved proportional-integral multiresonant (PIMR) scheme is proposed in [16] to consider a wide range of frequency fluctuation from 49.5 Hz to 50.5 Hz for 50 Hz frequency system. In this scheme, the varying fractional delay is realized by a finite impulse response (FIR) filter for adjustment of the controller parameters in order to match its resonant frequency with the grid frequency even when the frequency varies.…”

Section: Introductionmentioning

confidence: 99%

“…In this scheme, the varying fractional delay is realized by a finite impulse response (FIR) filter for adjustment of the controller parameters in order to match its resonant frequency with the grid frequency even when the frequency varies. However, these two methods require a heavier computational task and a higher cost, yielding an overall complexity due to the implementation of the Lagrange interpolating polynomial method [15] or the variation of the sampling rate [16]. In [17], a control method based on a linear parameter varying (LPV) approach is studied for a three-phase inverter to cope with the frequency fluctuation phenomenon.…”

Section: Introductionmentioning

confidence: 99%

A Robust Frequency-Adaptive Current Control of a Grid-Connected Inverter Based on LMI-LQR Under Polytopic Uncertainties

Bimarta

Kim

2020

IEEE Access

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This paper presents a frequency-adaptive current control design for a grid-connected inverter (GCI) with an inductive-capacitive-inductive (LCL) filter in the presence of grid disturbance such as the grid frequency variation and grid voltage harmonic distortion as well as polytopic uncertainties in the LCL filter parameters. The grid current control is achieved by augmenting integral and resonant terms into the LCL-filtered inverter system model to constitute integral-resonant full-state feedback control for zero steady-state error and current harmonic attenuation. To realize the full-state feedback control, the information on all the state variables is essential. However, additional sensors for state measurements increase the implementation cost as well as the complexity. To overcome this issue, a full-state discrete-time observer is employed in the stationary reference frame. Furthermore, to maintain the quality of grid currents injected into the grid, a frequency-adaptive current control is introduced. For this aim, the grid frequency is estimated through an adaptive observer rapidly and precisely. Then, the estimated grid frequency is used to adaptively change the frequency information in the augmented resonant controller for the purpose of producing high-quality grid currents even under both distorted grid voltages and grid frequency variation. In addition, to ensure the robustness against LCL filter parameter perturbation, a linear matrix inequalitylinear quadratic regulator (LMI-LQR) approach is proposed for polytopic uncertainties in the LCL filter parameters to design full-state feedback control as well as a full-state observer. To verify the effectiveness of the proposed control scheme, the simulation and experimental results are given. INDEX TERMSAdaptive observer, frequency-adaptive control, grid-connected inverter, linear matrix inequality (LMI), polytopic uncertainties.

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A Frequency Adaptive PIMR-Type Repetitive Control for a Grid-Tied Inverter

Cited by 26 publications

References 23 publications

Inverter harmonic perturbations rejection in renewable energy conversion systems applying a super‐twisting algorithm

Inverter harmonic perturbations rejection in renewable energy conversion systems applying a super‐twisting algorithm

Single-Stage Three-Phase Grid-Tied Isolated SEPIC-Based Differential Inverter With Improved Control and Selective Harmonic Compensation

A Robust Frequency-Adaptive Current Control of a Grid-Connected Inverter Based on LMI-LQR Under Polytopic Uncertainties

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