An Improved Second-Order Generalized Integrator Based Quadrature Signal Generator

Xin, Zhen; Wang, Xiongfei; Qin, Zian; Lu, Ming–Feng; Loh, Poh Chiang; Blaabjerg, Frede

doi:10.1109/tpel.2016.2576644

Cited by 209 publications

(102 citation statements)

References 11 publications

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“…As in the simulations, the current feedback signal is measured at the converter side. Therefore, the estimated capacitor current must be included in the calculation of the current reference, according to (10). As it is proven in the plots, the proposed system tracks the reference with fast dynamic response and has zero steady state error.…”

Section: Active and Reactive Power Controlmentioning

confidence: 92%

A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter

Roslan

Suul

Luna

et al. 2016

2016 IEEE Energy Conversion Congress and Exposition (ECCE)

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Abstract-Grid synchronization based on Virtual Flux (VF) estimation allows for control of grid-connected power converter without depending on AC-voltage measurements. This is useful in voltage-sensor-less applications for reducing cost and complexity of the control hardware, and can be utilized in case of limited reliability or availability of voltage measurements at the intended point of synchronization to the grid. However, for Voltage Source Converters (VSC) with LCL filters, the influence of the capacitor current must be taken into account to ensure accurate VF estimation at the Point of Common Coupling (PCC) with the grid. This paper presents a comparative evaluation of three VF-based methods for grid synchronization of VSCs with LCL filters, with three different ways of obtaining the capacitor current. The VF estimation in the first method is based only on the measured converter currents. The second method includes capacitor voltage measurements used for estimating the capacitor currents, while the capacitor currents are measured in the third approach. Comparative results from time-domain simulations are presented, demonstrating good performance of the estimation and accurate control of the active and reactive power at the PCC with all three methods, as long as sufficiently accurate filter parameters and current measurements are available. However, the approach based on capacitor current measurements is sensitive to noise due to the high ripple current compared to the fundamental frequency current in the capacitors. The operation of a converter with VF-based grid synchronization including estimation of the capacitor current is demonstrated by experimental results, verifying the voltage sensor-less operation with LCL-filter.

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Section: Active and Reactive Power Controlmentioning

confidence: 92%

A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter

Roslan

Suul

Luna

et al. 2016

2016 IEEE Energy Conversion Congress and Exposition (ECCE)

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show abstract

“…However, it increases the complexity resulting in heavy computation. To eliminate the DC offset and harmonics of SOGI-PLL under grid faults, several methods have been proposed in the literature [77]- [81]. A new second-order SOGI-QSG (SO-SOGI-QSG) presented [81] inherits the simplicity of the SOGI-QSG and also has better disturbance attenuation.…”

Section: A Voltage Detection Methodsmentioning

confidence: 99%

Power System Support Functions Provided by Smart Inverters—A Review

Zhao¹,

Chang²,

Shao³

et al. 2018

CPSS TPEA

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Renewable energy is seen as a viable alternative to traditional energy sources, and distributed generation (DG) based on renewable energy sources has experienced rapid growth worldwide. High penetration of renewable energy based DG systems makes the grid more vulnerable, and stricter standards have been issued for grid interconnection of DG systems. DG systems are expected to be controllable with high flexibility and reliability. Provision of grid support functions and ancillary services, such as reactive power control, fault ride-through and harmonic compensation, is the key to attaining higher utilization of DG. Such functionalities are implemented in new generation smart inverters, which can contribute to the reduced cost of energy and need for additional system resources. The state-of-the-art power system support functions are summarized in this paper for the purpose of enhancing operation in low-voltage networks. Experimental results are given to better understand the implementation of the functions.Index Terms-Fault ride-through, harmonic compensation, power system support functions, reactive power control, smart inverters.

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“…It is complicated to analyze and design PLL due to the high-order components in Equation (21). According to the reduction equivalent approach of higher-order PLL system in reference [28], this paper adopts the Pade approximation reduction approach in reference [29] …”

Section: Parameter Design Guidelinesmentioning

confidence: 99%

An Efficient Hybrid Filter-Based Phase-Locked Loop under Adverse Grid Conditions

Hui

Wang

2018

Energies

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Synchronous-reference-frame phase-locked loop (SRF-PLL) is widely used in grid synchronization applications. However, under unbalanced, distorted and DC offset mixed grid conditions, its performance tends to worsen. In order to improve the filtering capability of SRF-PLL, a modified three-order generalized integrator (MTOGI) with DC offset rejection capability based on conventional three order generalized integrator (TOGI) and an enhanced delayed signal cancellation (EDSC) are proposed, then dual modified TOGI (DMTOGI) filtering stage is designed and incorporated into the SRF-PLL control loop with EDSC to form a new hybrid filter-based PLL. The proposed PLL can reject the fundamental frequency negative sequence (FFNS) component, DC offset component, and the rest of harmonic components in SRF-PLL input three-phase voltages at the same time with a simple complexity. The proposed PLL in this paper has a faster transient response due to the EDSC reducing the number of DSC operators. A small-signal model of the proposed PLL is derived. The stability is analyzed and parameter design guidelines are given. Experimental results are included to validate the effectiveness and robustness of the proposed PLL.

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An Improved Second-Order Generalized Integrator Based Quadrature Signal Generator

Cited by 209 publications

References 11 publications

A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter

A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter

Power System Support Functions Provided by Smart Inverters—A Review

An Efficient Hybrid Filter-Based Phase-Locked Loop under Adverse Grid Conditions

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