Small-Signal Modelling and Stability Analysis of Current-Controlled Virtual Synchronous Generators

Sun, Dawei; Liu, H; Song, Peng; Zhu, Shouzhen; Wei, Zhe

doi:10.1088/1755-1315/192/1/012013

Cited by 5 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main factors affecting the damping of grid-connected IGs with inertial response were identified in [21], whose results clarified that the effect of virtual inertia is negligible, while the primary frequency regulation droop coefficient is the key factor to decide the oscillation modal characteristics. However, [22] got the opposite result. In [22], the stability analysis proved that a small growth of virtual inertia may contribute serious negative damping in high-frequency oscillation modes, but the variation of frequency-droop coefficient has little influence on system stability.…”

Section: Introductionmentioning

confidence: 94%

“…However, [22] got the opposite result. In [22], the stability analysis proved that a small growth of virtual inertia may contribute serious negative damping in high-frequency oscillation modes, but the variation of frequency-droop coefficient has little influence on system stability. Previous studies have provided inconsistent or even contradictory results.…”

Section: Introductionmentioning

confidence: 94%

“…It is believed in some work [17]- [19] that virtual inertia of IGs offered improved damping for frequency or small-signal stability of electrical network. However, some other studies [20], [22] reported that the inertial response of IGs would contribute to negative damping for system stability on some occasions. Based on the above observations, it is worth noting that no prior research on this subject has given mechanism explanation for the contradictory conclusions.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comparison of Different Virtual Inertia Control Methods for Inverter-based Generators

Sun

Liu

Shunan

et al. 2020

Journal of Modern Power Systems and Clean Energy

View full text Add to dashboard Cite

With the rapid development of inverter-based generators (IGs), power grid is faced with critical frequency stability challenges because the existing IGs have no inertia. To equip IGs with inertial response, researchers have proposed several virtual inertia control methods, which can be classified into two categories: virtual synchronous generator (VSG) control and droop control based on rate of change of frequency (ROCOFdroop control). In this paper, the comparison between both virtual inertia control methods is conducted from three perspectives: mathematical model, output characteristic and small-signal stability. State-space models are firstly built to analyze the control mechanism of VSG control and ROCOF-droop control methods. Simulation and eigenvalue analysis are conducted to study the transient responses and oscillation characteristics of both methods, which is helpful to understand the advantages and limitations of existing virtual inertia control methods. Finally, the obtained theoretical results are validated through realtime laboratory (RT-LAB) hardware-in-loop simulation platform.

show abstract

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of Different Virtual Inertia Control Methods for Inverter-based Generators

Sun

Liu

Shunan

et al. 2020

Journal of Modern Power Systems and Clean Energy

View full text Add to dashboard Cite

show abstract

“…, , = rj ii ri S K S   (10) where, , Ji K is the rotational inertia of electricity storage unit; i K is the distribution coefficient of each energy storage rotational inertia; f is the electricity frequency of the grid;  is the threshold value of the grid frequency deviation; , Di K is the damping of electricity storage unit; i  is the damping coefficient of each distributed electricity storage system;…”

Section: Coordinated Control Strategy Of the Grid-forming Energy Storagementioning

confidence: 99%

“…In [8][9], a current-controlled virtual synchronous generator (VSG) is proposed. In [10], a small-signal model of the currentcontrolled VSG is established, and the influence of parameters of current-controlled VSG on stability is studied. this paper shows that current-controlled virtual synchronous control would the responsibility to contribute to high-frequency or subsynchronous oscillation.…”

Section: Introductionmentioning

confidence: 99%

Coordinated Control Strategy of Emulated Inertia and Damping for Grid-Forming Energy Storage Considering Capacity Characteristics

Li¹,

Tang²,

Zhu³

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The grid-forming control method of the emulated synchronous generator can enhance the response capability of the electricity frequency and enhance the anti-interference capability of the new energy system. But the system frequency regulation ignores the fact that the active power of multiple energy storage is not proportional allocation, which can decrease the stability of the system. To solve this problem, a grid-forming control method of emulated rotational inertia and damping characteristics for multiple energy storage considering capacity characteristics is proposed. First, the control construction of the grid-forming inverter is presented, and the mathematical model of the grid-forming control of the emulated synchronous generator is established. Secondly, the frequency change and frequency deviation are introduced into the grid-forming control, and the grid-forming control method of emulated inertia and damping coefficient is designed. Each energy storage obtains the emulated rotational inertia and damping value through the real-time state of charge, which adjusts the frequency response of the power grid and active power of the distributed electricity storage system. And this method can realize proportional allocation according to the capacity of electricity storage system. Finally, the simulation analysis results of Matlab/Simulink simulation model is carried out to verify the effectiveness and feasibility of the proposed grid-forming control method.

show abstract

An adaptive multi‐mode switching control strategy to improve the stability of virtual synchronous generator with wide power grid strengths variation

Liu

Qin

Zhou

et al. 2022

IET Generation Trans & Dist

View full text Add to dashboard Cite

With the increasing proportion of renewable power generations in the power system, the power grid impedance may fluctuate greatly, and it is difficult for the virtual synchronous generator (VSG) with a single control structure to meet the stability requirements. Thus, the control principles of the two types of VSGs are compared to conclude that there are similarities in the control structure of the two VSGs. And the small signal models of the two types of VSGs are established to analyze the stability boundaries, coming to the conclusion that the stability region is complementary. Based on the conclusions, the paper puts forward the idea of switching operation modes: switch to the U‐VSG mode when the grid strength weakens and switch to the PQ‐VSG mode when greater, so that the inverter can keep stable in a wider range of grid strength. Therefore, the characterization method of the switching boundary with hysteresis properties is proposed. Then the improved recursive least squares (RLS) algorithm is introduced to identify the power grid impedance online without additional injected disturbance, based on which the adaptive multi‐mode smooth switching control strategy is proposed. Finally, the effectiveness of the analysis and the control strategy are verified by simulations.

show abstract

Small-Signal Modelling and Stability Analysis of Current-Controlled Virtual Synchronous Generators

Cited by 5 publications

References 7 publications

Comparison of Different Virtual Inertia Control Methods for Inverter-based Generators

Comparison of Different Virtual Inertia Control Methods for Inverter-based Generators

Coordinated Control Strategy of Emulated Inertia and Damping for Grid-Forming Energy Storage Considering Capacity Characteristics

An adaptive multi‐mode switching control strategy to improve the stability of virtual synchronous generator with wide power grid strengths variation

Contact Info

Product

Resources

About