Grid-forming converters, with their voltage-source characteristics, can independently provide voltage support and thus have become a critical supporting technology for new-type power systems. However, they suffer from overcurrent risks and insufficie...
The virtual synchronous generator (VSG) is an effective grid-forming control technique for power converters that are required to provide inertia, frequency support, and voltage support. This work focuses on balanced three-phase operation under symmet...
In recent decades, different control strategies have been designed for the increasing integration of distributed generation systems. These systems, most of them based on renewable energies, use electronic converters to exchange power with the grid. C...
With the integration of renewable energy and power-electronic devices, grid-forming modular multilevel converters (GFM-MMCs) play a critical role in active grid support. An AC grid voltage sag can trigger a large support current, which may cause larg...
The low voltage ride-through (LVRT) capability of the doubly-fed induction generator (DFIG) significantly impacts upon the integration of wind power into the power grid. This paper develops a novel comprehensive control strategy to enhance the LVRT a...
This paper presents a controller for a direct current (DC) grid-connected single-stage solar photovoltaic (PV) converter. The proposed controller provides both static and dynamic voltage support to the grid voltage. Unlike the common practice, it all...
The large-scale integration of wind power significantly alters the voltage dynamic characteristics of power systems. Wind turbines have a weak ability to withstand grid disturbances and have difficulty in providing effective reactive power support du...
The charging station (CS) is generally directly off-grid under a grid fault, which has become a key technical bottleneck that restricts the sustainable development of new energy transportation systems. During a grid fault, the CS under the vehicle-to...
Microgrids are commonly connected through medium-voltage cables in coastal distribution networks and other microgrids. However, a faulted microgrid may increase the collapse risk if the supporting microgrids are disconnected due to voltage sags. Conv...
To address the security and stability requirements of renewable energy clusters under extreme weather conditions, this study investigates the coordinated voltage support mechanisms between grid-following and grid-forming converters. This paper propos...
New grid-connected systems have imposed additional requirements regarding reliability, power quality, high levels of power processing capacity, and fault support, where power converters have a crucial role in fulfilling these requirements. Overcoming...
To ensure system stability, national grid codes often require converter-based generators to provide fault-ride-through (FRT) capabilities and dynamic voltage support, according to which they should stay connected and support the voltage during fault...
As flexible and controllable resources, PV and wind power can provide effective cooperative voltage support in renewable-rich distribution networks. This paper proposes a multi-resource cooperative voltage support strategy based on an improved partic...
This paper presents the development of a decision support system (DSS) for a low-voltage grid with renewable energy sources (photovoltaic panels and wind turbine) which aims at achieving energy balance in a pilot microgrid with less energy consumed f...
To improve voltage support at the point of common coupling of renewable energy collection stations connected to weak grids, this paper proposes a synchronous machine-like outer reference generator for a conventional fixed-PQ voltage-source converter...
With the integration of a high proportion of distributed generators (DGs), the imbalance between source and load power intensifies, causing the distribution grid to become ‘weak’ during certain periods, which can easily lead to voltage ov...
To address rapid frequency decline, transient voltage violations, and excessive configuration costs caused by competition between active and reactive power support in weak grids, this paper proposes an optimal configuration method that incorporates t...
This paper proposes a control technique for a large-scale grid-connected photovoltaic (PV) plant that maintains the connection of an inverter to the grid voltage under different types of faults, while injecting a reactive power to accommodate the req...
With the increasing penetration of distributed generation and the diversification of electrical equipment, distribution networks face issues like three-phase unbalance and harmonic currents, while the voltage stability and inertia of the grid-connect...
Static synchronous compensators (STATCOMs) are widely applied in modern power networks for reactive power compensation and grid voltage regulation. Compared to the conventional compensation devices, the STATCOMs deliver superior performance through t...
A novel nonlinear current-limiting controller for three-phase grid-tied droop-controlled inverters that is capable of offering voltage support during balanced and unbalanced grid voltage drops is proposed in this paper. The proposed controller introd...
This paper presents an optimized control strategy based on a Doubly Fed Induction Generator (DFIG) and Gravity Energy Storage System (GESS) for AC voltage support in unbalanced grid conditions. The presented control aims to achieve precise rotational...
In islanded microgrids with high-proportion renewable energy, the disconnection from the main grid leads to the characteristics of low inertia, weak damping, and high impedance ratio, which exacerbate the safety risks of frequency and voltage. To bal...
High penetration of grid-following (GFL) wind farms can aggravate voltage recovery problems in weak distribution networks. Although static var generators (SVGs) can provide rapid reactive-power support, their planning effectiveness varies significant...
The weak grid strength in regions with large-scale renewable energy integration has emerged as a universal challenge, limiting the further expansion of renewable energy development. Currently, the short-circuit ratio (SCR) is widely used to quantify...
High levels of photovoltaic penetration and synchronous generator decommissioning are weakening grid strength and increasing voltage support requirements, yet most studies still assess support technologies primarily based on technical performance rat...
The joint is the weakest link in three-core medium-voltage power cable systems and the temperature is an essential indicator to its insulation condition. Therefore, a model to estimate the temperature inside the three-core cable joint was built based...
Mechanical faults of high voltage circuit breakers (HVCBs) are one of the most important factors that affect the reliability of power system operation. Because of the limitation of a lack of samples of each fault type; some fault conditions can be re...
High-voltage circuit breakers (HVCBs) are critical switching devices whose mechanical reliability directly affects power system safety and operational continuity. Accurate fault diagnosis remains challenging due to nonlinear vibration characteristics...
When droop control of virtual synchronous generators (VSGs) with rotational inertia is adopted in islanded alternating current (AC) microgrids, the coupling mechanism among reactive power loads, control parameters and system virtual inertia remains u...
This article proposes a novel equivalent control method for voltage source inverters (VSI) with disturbance observers (DOB) to support the symmetric and asymmetric voltage requirements of a micro-grid (MG) while also matching the MG output power requ...
This paper presents a community energy management system (CEMS) for coordinating flexible residential devices, including electric vehicles (EVs), heat pumps, photovoltaic (PV) systems, and batteries. The framework focuses on demand-side flexibility a...
High photovoltaic (PV) penetration can reduce grid-energy imports but may worsen voltage performance in radial distribution feeders. This paper develops a unified mixed-discrete PV–BESS planning framework that jointly optimizes siting, sizing,...
A high share of distributed energy resources (DERs) in power distribution grids has posed many challenges for system operation and control. Microgrid (MG) application with different distributed control approaches for DERs has been drawn a lot of atte...
The increased penetration of renewable energy resources with low inertia poses a risk to the frequency and voltage stability of modern power systems. Therefore, it is important to investigate grid-support functions from inverter-interfaced technologi...
After the large-scale access of distributed power sources to the distribution network, significant high/low voltage problems have emerged. Using a virtual power plant to provide reactive power voltage regulation as an ancillary service effectively ad...
The frequency support capacity of power loads is essential for maintaining active power symmetry and balance between the generation and demand sides of power systems. As the proportion of renewable energy sources and power electronic equipment increa...
With the increasing penetration of renewable energy generation, large-scale voltage dips may cause significant active power deficits and threaten system frequency stability. To address the issue, this article proposes a two-stage control strategy to...
To address active voltage control in photovoltaic (PV)-integrated distribution networks characterized by weak voltage support conditions, this paper proposes a multi-agent deep reinforcement learning (MADRL)-based coordinated control method for PV cl...
The increasing uncertainty of distributed energy resources (DERs) challenges the secure and resilient operation of low-voltage distribution networks (LVDNs). Flexible interconnection via power-electronic devices enables controllable links among LVDAs...
As renewable generation and power-electronic interfaces account for a growing share of power systems, reduced system inertia and weakened voltage support place greater demands on the stable operation of weak and passive networks. This paper proposes...
With the large-scale integration of renewable energy sources, grid-forming (GFM) converters with inherent voltage and frequency support capabilities have attracted significant attention. However, due to the limited overcurrent withstand capability of...
This paper outlines some modifications to conventional active power filters (APFs) to compensate for the non-linearity of the load current. Since the APFs inject the required non-linearity of the load harmonic current to make the current source sinus...
The increasing penetration of Doubly Fed Induction Generator (DFIG)-based wind energy systems raises major concerns regarding voltage stability and Fault Ride-Through (FRT) capability under grid disturbances and wind speed variations. This paper prop...
High-power DC electric vehicle supply equipments (EVSE) have a significant impact on voltage stability in low-voltage networks. To ensure the guaranteed voltage characteristics, utility grid operator permit the installation of DC-EVSE only in proximi...
This paper proposes a coordinated low-voltage ride-through (LVRT) control framework for three-phase converter-interfaced distributed generation (DG) systems that integrates autocorrection droop control (AcDC) and Adaptive Current-Limited Reactive Pri...
Enhancing system strength to ensure voltage security has become a critical challenge for power systems with high penetration of renewable energy (RE). As China accelerates its clean-energy transition, the conventional grid dominated by synchronous ge...
High penetration of Inverter-Based Resources (IBRs) into the power grid could diminish the rotational inertia offered by a traditional power system and thus impact frequency stability. Several techniques are adopted to provide virtual inertial suppor...
Grid-forming (GFM) control is an important technical solution for addressing the declining voltage-support capability and inertia level of modern power systems. By integrating a high-voltage directly connected grid-side converter with supercapacitors...
Renewable power plants connected to low-system-strength grids are increasingly dominated by inverter-based resources (IBRs). Their point of common coupling (PCC) voltage is therefore shaped not only by reactive-power support but also by active-power...
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