Symmetrical PLL for SISO Impedance Modeling and Enhanced Stability in Weak Grids

Dongsheng Yang, Xiongfei Wang, Fangcheng Liu, Kai Xin, Yunfeng Liu, Frede Blaabjerg

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

This paper proposes a symmetrical phase-locked loop (PLL) that can eliminate the frequency-coupling terms caused by the asymmetric dynamics of conventional PLLs. In the approach, a concept of complex phase angle vector with both real and imaginary phase components is introduced, which enables to control the direct- and quadrature- axis components with symmetrical dynamics. The small-signal impedance model that characterizes the dynamic effect of the symmetrical PLL on the current control loop is also derived, which, differing from the conventional multiple-input-multiple-output (MIMO) impedance matrix, is in a single-input-single-output (SISO) form based on complex transfer functions. This SISO representation allows for a design-oriented analysis. Moreover, the undesired sub-synchronous oscillation caused by the conventional asymmetrical PLL can be avoided, and the classical SISO impedance shaping can be utilized to cancel the negative resistor behavior caused by PLL thus can greatly enhance the grid synchronization stability under weak grid conditions. The effectiveness of the theoretical analysis is validated by experimental tests.
OriginalsprogEngelsk
TidsskriftIEEE Transactions on Power Electronics
Antal sider12
ISSN0885-8993
DOI
StatusE-pub ahead of print - jun. 2019

Fingerprint

Phase locked loops
Electric current control
Resistors
Transfer functions
Synchronization

Emneord

  • Phase locked loops
  • Impedance
  • Stability analysis
  • MIMO communication
  • Power system stability
  • Transfer functions
  • Oscillators
  • Frequency coupling
  • PLL
  • impedance modeling
  • MIMO
  • SISO impedance shaping

Citer dette

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title = "Symmetrical PLL for SISO Impedance Modeling and Enhanced Stability in Weak Grids",
abstract = "This paper proposes a symmetrical phase-locked loop (PLL) that can eliminate the frequency-coupling terms caused by the asymmetric dynamics of conventional PLLs. In the approach, a concept of complex phase angle vector with both real and imaginary phase components is introduced, which enables to control the direct- and quadrature- axis components with symmetrical dynamics. The small-signal impedance model that characterizes the dynamic effect of the symmetrical PLL on the current control loop is also derived, which, differing from the conventional multiple-input-multiple-output (MIMO) impedance matrix, is in a single-input-single-output (SISO) form based on complex transfer functions. This SISO representation allows for a design-oriented analysis. Moreover, the undesired sub-synchronous oscillation caused by the conventional asymmetrical PLL can be avoided, and the classical SISO impedance shaping can be utilized to cancel the negative resistor behavior caused by PLL thus can greatly enhance the grid synchronization stability under weak grid conditions. The effectiveness of the theoretical analysis is validated by experimental tests.",
keywords = "Phase locked loops, Impedance, Stability analysis, MIMO communication, Power system stability, Transfer functions, Oscillators, Frequency coupling, PLL, impedance modeling, MIMO, SISO impedance shaping, Frequency coupling, PLL, Impedance modeling, MIMO, SISO impedance shaping",
author = "Dongsheng Yang and Xiongfei Wang and Fangcheng Liu and Kai Xin and Yunfeng Liu and Frede Blaabjerg",
year = "2019",
month = "6",
doi = "10.1109/TPEL.2019.2917945",
language = "English",
journal = "I E E E Transactions on Power Electronics",
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Symmetrical PLL for SISO Impedance Modeling and Enhanced Stability in Weak Grids. / Yang, Dongsheng; Wang, Xiongfei; Liu, Fangcheng; Xin, Kai; Liu, Yunfeng; Blaabjerg, Frede.

I: IEEE Transactions on Power Electronics, 06.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Symmetrical PLL for SISO Impedance Modeling and Enhanced Stability in Weak Grids

AU - Yang, Dongsheng

AU - Wang, Xiongfei

AU - Liu, Fangcheng

AU - Xin, Kai

AU - Liu, Yunfeng

AU - Blaabjerg, Frede

PY - 2019/6

Y1 - 2019/6

N2 - This paper proposes a symmetrical phase-locked loop (PLL) that can eliminate the frequency-coupling terms caused by the asymmetric dynamics of conventional PLLs. In the approach, a concept of complex phase angle vector with both real and imaginary phase components is introduced, which enables to control the direct- and quadrature- axis components with symmetrical dynamics. The small-signal impedance model that characterizes the dynamic effect of the symmetrical PLL on the current control loop is also derived, which, differing from the conventional multiple-input-multiple-output (MIMO) impedance matrix, is in a single-input-single-output (SISO) form based on complex transfer functions. This SISO representation allows for a design-oriented analysis. Moreover, the undesired sub-synchronous oscillation caused by the conventional asymmetrical PLL can be avoided, and the classical SISO impedance shaping can be utilized to cancel the negative resistor behavior caused by PLL thus can greatly enhance the grid synchronization stability under weak grid conditions. The effectiveness of the theoretical analysis is validated by experimental tests.

AB - This paper proposes a symmetrical phase-locked loop (PLL) that can eliminate the frequency-coupling terms caused by the asymmetric dynamics of conventional PLLs. In the approach, a concept of complex phase angle vector with both real and imaginary phase components is introduced, which enables to control the direct- and quadrature- axis components with symmetrical dynamics. The small-signal impedance model that characterizes the dynamic effect of the symmetrical PLL on the current control loop is also derived, which, differing from the conventional multiple-input-multiple-output (MIMO) impedance matrix, is in a single-input-single-output (SISO) form based on complex transfer functions. This SISO representation allows for a design-oriented analysis. Moreover, the undesired sub-synchronous oscillation caused by the conventional asymmetrical PLL can be avoided, and the classical SISO impedance shaping can be utilized to cancel the negative resistor behavior caused by PLL thus can greatly enhance the grid synchronization stability under weak grid conditions. The effectiveness of the theoretical analysis is validated by experimental tests.

KW - Phase locked loops

KW - Impedance

KW - Stability analysis

KW - MIMO communication

KW - Power system stability

KW - Transfer functions

KW - Oscillators

KW - Frequency coupling

KW - PLL

KW - impedance modeling

KW - MIMO

KW - SISO impedance shaping

KW - Frequency coupling

KW - PLL

KW - Impedance modeling

KW - MIMO

KW - SISO impedance shaping

U2 - 10.1109/TPEL.2019.2917945

DO - 10.1109/TPEL.2019.2917945

M3 - Journal article

JO - I E E E Transactions on Power Electronics

JF - I E E E Transactions on Power Electronics

SN - 0885-8993

ER -