557 Results Found

The feasibility of power transfer enhancement, through simultaneous AC–DC power transmission in a two-terminal transmission network, has been proposed earlier by the authors, and the concept is well established. To meet the increase in demand f...

This article presents a recursive solution to the power-transmission loss in DC-powered networks. In such a network, the load cannot be modeled as a fixed equivalent resistance value, since the switching regulator may draw more or less current based...

Owing to the diverse connection configurations of dual active bridge converters, a multiplicity of low-voltage DC port structures are anticipated to emerge in the independent DC bus structure multiport power electronic transformer (IDBS-MPET). An ina...

At present, the continuous growth of renewable energy integration and power grid load demand has placed higher requirements on the transmission capacity and power flow control capability of power systems. Owing to its flexible and controllable power...

For the controllability of the transmission power of DC transmission channels, the optimal power distribution (OPD) of AC-DC parallel transmission channels is an effective measure for improving the economic operation of an AC-DC interconnected power...

AC/DC parallel transmission is a critical approach for large-scale centralized transmission. Existing assessments of power transfer capability in AC/DC corridors rarely incorporate comprehensive security and stability constraints, potentially leading...

Subsequent commutation failures (CFs) in HVDC systems will cause large-scale power flow transfer in AC/DC transmission systems and lead to overload risk in HVAC systems. In order to cope with these effects, a power coordination control strategy for t...

To maintain voltage stabilization under transmission time delays, this paper proposes a seamless power management scheme for a distributed DC microgrid (DCMG) with minimum digital communication links (DCLs). First, a DCL topology with minimum communi...

With the increasing integration of HVDC tie-lines, the regional power systems in both the energy-exporting area and the energy-importing area have been gradually evolving into “strong DC, weak AC” systems. In this paper, a multi-period tr...

This paper aims to unveil the symmetry–asymmetry transition mechanisms in transient fault waveforms of offshore wind power AC/DC transmission systems, addressing the critical limitation of traditional simulation methods of the fact that they ca...

This paper reviews state-of-the-art architectures for galvanically isolated DC-DC converters with data transmission for low-power applications. Such applications do not have stringent requirements, in terms of power efficiency, but ask for very compa...

With the increasing proportion of renewable energy in power grids, the inertia level and frequency regulation capability of modern power systems have declined. In response, this paper proposes a coordinated frequency regulation strategy integrating p...

Nowadays, intermittent energy resources, such as wind turbines, and direct current (DC) transmission have been extensively integrated into power systems. This paper proposes an identifying method for weak lines of novel power systems with intermitten...

The impact of subsynchronous oscillation (SSO) on grid security is becoming increasingly prominent with the rapid development of a large new energy base. However, the SSO modes and characteristics in complex power systems where series-complementary A...

Wind power is currently the most mature representative of sustainable energy generation technology, which has been developed and utilized on a large scale worldwide. The random and fluctuating nature of wind power output poses a threat to the secure...

Gas-insulated power transmission lines (GILs) can replace cables and overhead transmission lines, playing an important role in DC transmission systems. However, the influence of surface charge accumulation on insulation reliability cannot be ignored...

With the rapid development of high-voltage direct current (HVDC) transmission systems, the coupling between AC and DC grids is becoming increasingly close. Voltage disturbances in the grid can easily cause commutation failures in the DC system, threa...

As the quantity of direct current (DC) load and wireless power transmission (WPT) devices are continuously increasing in building, in order to efficiently utilize renewable energy (which outputs DC power) such as photovoltaic (PV), especially for bui...

With the large-scale deployment of renewable energy, transmission systems for new energy sources are increasingly exposed to transient overvoltage issues induced by DC blockages and commutation failures. To address the challenges of an imprecise resp...

Several countries around the world are undergoing a radical transformation of their electricity networks, with the widespread integration of distributed generation based on renewable energy sources at the center of the change. Under these scenarios,...

In high voltage direct current (HVDC) power transmission of offshore wind power systems, DC/DC converters are applied to transfer power from wind generators to HVDC terminals, and they play a crucial role in providing a high voltage gain, high effici...

In order to improve the stability of direct current (DC) microgrid with constant power loads, a novel virtual inductive approach is proposed in this paper. It is known that the negative impedance characteristic of constant power loads will lead to DC...

Dead-time effect has become an apparent issue in high-switching-frequency high-power dual active bridge (DAB) DC-DC converter. This paper gives a detailed analysis of phase-shift errors effect caused by dead time, including output voltage offset, sof...

High-voltage flexible power systems, with their intrinsic characteristics, play an increasingly important role in electronic power systems. Synchronization between the inverter and the grid needs to be achieved by a phase-locked loop (PLL), the perfo...

This paper proposes a novel extended-single-phase shift (ESPS) control strategy of isolated bidirectional full-bridge DC-DC converters (IBDCs) which are a promising alternative as a power electronic interface in microgrids with an additional function...

For achieving the European renewable electricity targets, a significant contribution is foreseen to come from offshore wind energy. Considering the large scale of the future planned offshore wind farms and the increasing distances to shore, grid inte...

A desire to produce power in microgrids has grown as the demand for electricity has expanded and the cost of installing modern transmission lines over long distances has become infeasible. As such, microgrids pose DC/AC harmonic distortion losses to...

To address the critical issue of low reliability caused by fault impacts in large-scale wind farms transmitting power over long distances via flexible DC transmission systems, this study proposes a collaborative solution. First, a new protection sche...

The ever increasing development and availability of power electronic systems is the underpinning technology that enables large scale integration of wind generation plants with the electricity grid. As the size and power capacity of the wind turbine c...

AC-DC hybrid distribution grids realize power transmission through tie lines. Accurately characterizing the power exchange capacity between regional grids while ensuring safe grid operation is the basis for the coordinated scheduling of resources in...

For radio frequency energy transmission, the conversion efficiency of the receiver is decisive not only for reducing sending power, but also for enabling energy transmission over long and variable distances. In this contribution, we present a passive...

The series-connected DRU-MMC hybrid converter, with its compact size and cost-effectiveness, presents an attractive solution for long-distance offshore wind power transmission. However, its application is limited by the DRU’s unidirectional pow...

This research aims to maximize the resilience of an electrical power system after an N−1 contingency, and this objective is achieved by switching the transmission lines connection using a heuristic that integrates optimal dc power flows (DCOPF)...

High Voltage Direct Current (HVDC) transmission represents the most efficient way for transporting produced electrical energy from remotely located offshore wind farms to the shore. Such systems are implemented today using very expensive and large po...

A DC power flow controller (DCPFC) can help to facilitate power flow routing in the multi-terminal high-voltage direct current (HVDC) transmission system. Realizing its multi-port output can effectively improve the device regulate range and capabilit...

Overhead transmission line conductors are usually helically stranded. The current-carrying section is made of aluminum and/or aluminum alloys. Several factors affect their electrical resistance, such as the conductivity of the conductor material, the...

In this study, we propose the use of a short-distance and fixed-type wireless power transmission transformer via a half-bridge LLC resonant converter. A ceramic insulating layer was used instead of an air gap, meaning that the heat generated from the...

This paper focuses on the Input-Independent Output-Series (IIOS) DC converters within fully DC aggregation systems, which enable independent submodule control and high voltage gain. DC aggregation systems experience output voltage imbalance among sub...

Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT) and...

DC microgrids have become a prevalent topic in research in part due to the expected superior efficiency of DC/DC converters compared to their AC/DC counterparts. Although numerous side-by-side analyses have quantified the efficiency benefits of DC po...

The ever-growing scale of offshore wind power integration has led coastal provincial power grids to face the common issue of insufficient AC grid structure capacity. An effective solution involves constructing an offshore–onshore mono–bip...

This paper introduces a DC–DC buck converter on the secondary side of the capacitive power transfer system to reduce the voltage and electric field across the interface, and to reduce the circuit Q, and thus the system sensitivity. The system i...

In this paper, we propose a new type of smoothing reactor using different types of reactors with different magnetic flux saturation to construct a DC-DC converter with low current ripple under the light load of the bidirectional DC-DC converter. Redu...

A promising solution for inductive power transfer and wireless charging is presented on the basis of a single-phase three-level T-type Neutral Point Clamped GaN-based inverter with two coupled transmitting coils. The article focuses on the feasibilit...

This paper presents an inductive power transfer system on the basis of a double single-phase three-level T-type inverter and two split transmitting coils for constant current and constant voltage wireless charging of low-voltage light electric vehicl...

A reliable and cost-effective mechanical direct current circuit breaker (DCCB) is a promising solution for DC interruption. However, the typical mechanical DCCB has difficulty in interrupting a rated current, because the high oscillating current supe...

In this article, the concept of a 22-kW microwave-powered unmanned aerial vehicle is presented. Its system architecture is analyzed and modeled for wirelessly transferring microwave power to the flying UAVs. The microwave system transmitting power at...

This work presents the optimization of antenna captured low power radio frequency (RF) to direct current (DC) power converters using Schottky diodes for powering remote wireless sensors. Linearized models using scattering parameters show that an ante...

This paper proposes a compact rectifier design method for utilizing harmonics. Based on total reflection generated by pure reactance loads at the second harmonic (2nd) and open circuit at the third harmonic (3rd), a compact DC-pass filter is designed...

When wind power is transmitted via high-voltage direct current (HVDC), the problem of high-voltage ride-through (HVRT), caused by direct-current (DC) blocking must be seriously taken into account. All the wind turbines in a wind farm are usually equi...