Frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators under distorted grid conditions

Yingjie WANG; Haiyuan LIU; Xuelong HAN; Kangan WANG

Article Details

Frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators under distorted grid conditions

Authors:

Yingjie WANG | Haiyuan LIU | Xuelong HAN | Kangan WANG

Publisher:

TUBITAK

Journal:

Turkish Journal of Electrical Engineering and Computer Science 2015 Vol.23 Issue 6, pp.1930-1945

Document Type:

Article

Publication Date:

12/2015

Document Language:

Turkish

Document ID (Org No.):

2000742427

Frequency:

Bimonthly

eISSN:

1303-6203

pISSN:

1300-0632

Abstract:

 

With some of the intermittent new energy and large nonlinear loads, grid voltage unbalance, harmonics, and frequency deviation are increasing year by year. The voltage source converter (VSC) is seriously affected by the various unexpected factors, and the presence of grid impedance makes the situation worse. In order to make the VSC track the nonideal grid quickly and accurately, this paper proposes a frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators (MSOGI-GVFS). Key expressions of the MSOGI-GVFS and its frequency response characteristics are described in this paper. A second-order generalized integrator configured as a quadrature signal generator generates a specific-frequency virtual flux. A harmonics decoupling network achieves fundamental and harmonic components of the virtual flux. The positive- and negative-sequence components are separated by multiple positive- and negative-sequence calculators. A frequency-locked loop is used to track the grid angular frequency. Finally, after compensating the voltage and the flux on the grid impedance and the filtering inductor, it accurately achieves the estimation of the grid virtual flux in the highly polluted grid environment. This method may reduce the voltage sensors, eliminate the influence of grid impedance, and track the grid frequency quickly, which contributes to the stability of the VSC. The good performance of MSOGI-GVFS is verified by simulation and experimental results.

 

With some of the intermittent new energy and large nonlinear loads, grid voltage unbalance, harmonics, and frequency deviation are increasing year by year. The voltage source converter (VSC) is seriously affected by the various unexpected factors, and the presence of grid impedance makes the situation worse. In order to make the VSC track the nonideal grid quickly and accurately, this paper proposes a frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators (MSOGI-GVFS). Key expressions of the MSOGI-GVFS and its frequency response characteristics are described in this paper. A second-order generalized integrator configured as a quadrature signal generator generates a specific-frequency virtual flux. A harmonics decoupling network achieves fundamental and harmonic components of the virtual flux. The positive- and negative-sequence components are separated by multiple positive- and negative-sequence calculators. A frequency-locked loop is used to track the grid angular frequency. Finally, after compensating the voltage and the flux on the grid impedance and the filtering inductor, it accurately achieves the estimation of the grid virtual flux in the highly polluted grid environment. This method may reduce the voltage sensors, eliminate the influence of grid impedance, and track the grid frequency quickly, which contributes to the stability of the VSC. The good performance of MSOGI-GVFS is verified by simulation and experimental results.

Article Details

Frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators under distorted grid conditions

Authors: Yingjie WANG | Haiyuan LIU | Xuelong HAN | Kangan WANG

Publisher: TUBITAK

Journal: Turkish Journal of Electrical Engineering and Computer Science 2015 Vol.23 Issue 6, pp.1930-1945

Document Type: Article

Publication Date: 12/2015

Document Language: Turkish

Document ID (Org No.): 2000742427

Frequency: Bimonthly

eISSN: 1303-6203

pISSN: 1300-0632

Issues

Authors:

Yingjie WANG | Haiyuan LIU | Xuelong HAN | Kangan WANG

Publisher:

TUBITAK

Journal:

Turkish Journal of Electrical Engineering and Computer Science 2015 Vol.23 Issue 6, pp.1930-1945

Document Type:

Article

Publication Date:

12/2015

Document Language:

Turkish

Document ID (Org No.):

2000742427

Frequency:

Bimonthly

eISSN:

1303-6203

pISSN:

1300-0632