Large-scale integration of renewable energy sources in power system leads to the replacement conventional plants (CPPs) and consequently challenges reliability security are introduced. This study is focused on improving grid frequency response after a contingency event with high penetration wind power. An storage (ESS) might be viable solution for providing inertial primary regulation. A methodology has been presented here sizing ESS terms required energy. It describes contribution grid,...

In the Low-Voltage (LV) AC microgrids (MGs), with a relatively high R/X ratio, virtual impedance is usually adopted to improve performance of droop control applied Distributed Generators (DGs).At same time, LV DC microgrid using as emerging without adequate power flow studies.In this paper, analyses for both and are formulated implemented.The mathematical models types considering concept used be in conformity practical distributed generators.As result, calculation accuracy improved analyses,...

In this paper, an economic dispatch problem for total operation cost minimization in dc microgrids is formulated. An operating associated with each generator the microgrid, including utility grid, combining cost-efficiency of system demand response requirements utility. The power flow model included optimization problem, thus transmission losses can be considered generation dispatch. By considering primary (local) control grid-forming converters a optimal parameters directly applied to...

The development of distributed generation system and electric vehicles is bound to strain the distribution network. A typical radial feeder suffers from voltage fluctuation overload in presence a large amount variable renewable generation. This paper presents concept enhancing power handling capacity networks using dc grid interconnections. Control both active reactive exchange between ac interconnecting converter has been proposed for regulation at terminal. Besides, interconnection also...

The virtual synchronous generator (VSG) control has been extensively applied for realizing grid-friendly interconnections of power converters. Nevertheless, due to the direct shaft dynamics emulation, low-frequency oscillations may be introduced in case limited damping effects. To solve this issue, law modifications have proposed based on feedback theory. Although can suppressed an acceptable level, original inertial response VSG will significantly degraded. This letter proposes a new method...

Large offshore wind power plants may have multi-MW turbine generators (WTG) equipped with full-scale converters (FSC) and voltage source converter (VSC) based high direct-current (HVDC) transmission for grid connection. The electronic in the WTG-FSC VSC-HVDC allow fast current control grid. This paper presents a method of controlling negative sequence injection into from as well WTG-FSCs. would minimize oscillations hence reduce dc overshoots system WTG-FSCs; especially when is unbalanced...

This paper deals with the operation of a cascaded H-bridge (CHB) converter-based STATCOM under unbalanced grid conditions. Degrees freedom and operational limitations CHB during condition are analyzed according to converter power flow equations. Based on this analysis, an improved low-voltage ride-through (LVRT) strategy for is proposed. In strategy, operator can control both positive- negative-sequence reactive currents independently within range STATCOM. addition, keep submodules'...

This article proposes a machine learning (ML)-based emulation of model predictive control (MPC) for modular multilevel converters (MMCs). In particular, the artificial neural network model, trained offline by data collected from traditional fast MPC method, is used to MMCs with high accuracy. With this training, majority computational burden transferred online offline. Therefore, proposed ML can replace role MPC. The experimental results show that ML-based has same performance as...

In recent years, the integration of high-power static synchronous compensator (STATCOM) and energy storage in same device has gained interest. Such a system is referred to as ES-STATCOM. Modular multilevel converter (MMC) topologies constitute promising family for ES-STATCOM realization, providing modular scalable solution with high efficiency that handles high-voltage ratings grid applications. There gap technical literature discussing design comparison MMC-based ES-STATCOMs while utilizing...

In this letter, a novel control scheme is proposed by combining the fractional-order and virtual synchronous generator, whereby more degrees of freedom are involved in controller design. A well-damped power without oscillations achieved. At same time, significant improvement inertial effect attained. Both theoretical experimental results have validated feasibility.

To eliminate low-frequency oscillations, this paper proposes an active-damping method for multiple grid-tied virtual synchronous generators (VSGs) in a power plant. Firstly, using the Lyapunov's indirect method, damping ratio of VSGs parallel is analyzed. The average reveals that multi-VSG plant can be poorly damped wide range inertia and settings. Then, self- mutual-damping controllers are developed to suppress mutually induced respectively. For practical implementation, adaptive tuning...

Large and distant offshore wind power plants can be efficiently connected to the onshore grid network using VSC-HVDC (Voltage Source Converter based HVDC) transmission. Chopper controlled resistors used limit DC line over-voltage when there is a fault on AC transfer obstructed. Considering development of full scale converter turbine generators (WTG), use unit rated chopper for each AC-DC-AC system individual turbines has been proposed in place one HVDC side. Both cases have simulated their...

The increased grid-penetration levels of energy produced by renewable sources, which have almost no inertia, might a negative impact on the reliable and stable operation power system. Various solutions for mitigating aforementioned problem were proposed in literature. aim this paper is to evaluate technical viability utilizing storage systems based Lithium-ion batteries providing inertial response grids with high penetration wind power. In order perform evaluation, 12-bus system grid model...

The paper gives an overview of HVAC and HVDC connection wind farm to the grid, with emphasis on voltage source converter (VSC)-based for large farms requiring long distance cable connection. Flexible control capabilities a VSC-based system enables smooth integration into power grid network while meeting code requirements (GCR). Operation is described.

This paper explores the application of modular multi-level converters (MMC) as a means for harnessing power from off-shore wind plants. The MMC consists large number simple voltage sourced converter (VSC) submodules that can be easily assembled into high-voltage and high power. shows has fast response low harmonic content in comparison with two-level VSC option. discusses modeling approach used, including solution to challenge imposed by very switching devices MMC. (5 pages)

Due to the high integration of renewable energy, power systems may become more susceptible unbalanced grid voltages, frequency disturbances, harmonic resonances and others. Therefore, several works have pointed out that ancillary services provided by energy storage can minimize these issues. The combination static synchronous compensators (ES-STATCOM) has been proposed reduce cost. Modular multilevel converters (MMC) are featured as a good solution for ES-STATCOM realization, due their...

The AC-DC hybrid microgrid is an effective form of utilizing different energy resources and the analysis this system requires a proper power flow algorithm. This paper proposes suitable algorithm for LV based on droop control virtual impedance. Droop impedance concepts AC network, DC network interlinking converter are reviewed so as to model it in analysis. validation verified by comparing with steady state results from detailed time domain simulation. effectiveness proposed makes potential...

High penetration of distributed energy resources (DERs) creates various protection challenges, such as blinding, false tripping, unsynchronized reclosing, etc. Additionally, adaptation active network management approaches namely demand response and reconfiguration also threats existing practice. In this study, a combination local adaptive communication assisted central is proposed, whereby the relay settings are dynamically updated based on online identification topologies status DERs....

A novel capacitor voltage balancing scheme for modular multilevel cascade converter-double-star chopper-cells (MMCC-DSCC)-based STATCOM is proposed in this paper. Compared with the conventional software methods, has three main advantages. First, only six sensors are needed, and other have been removed. Then, control framework can be simple without sort select process, or some loops. Additional delay process caused by sampling signals transmission also mitigated. Finally, faster speed...

The capacitor voltage ripples of the modular multilevel converter (MMC) are increased under unbalanced grid fault conditions. Since high deteriorate their lifetimes and may even cause tripping MMC system, it is important to restrict them. To this end, well known that injecting double fundamental frequency circulating currents can reduce ripples. However, finding a proper current reference achieve desired analytically complicated. This letter proposes an alternative method quickly calculate...

In this paper, an improved power flow analysis algorithm for distributed generation (DG) units controlled with P/Q droop functions and virtual impedances in a low voltage (LV) microgrid is proposed. The proposed provides contrast to conventional calculation techniques: (i) consideration of impedance parameters (ii) higher accuracy reactive calculation. paper validated by comparing the results detailed time domain simulation results. Case studies have been carried out analyzing effects...