Purpose Under the background that engineering, procurement and construction (EPC) contracting model is introduced to adapt highly fragmented characteristics of prefabricated construction, schedule management general contractor faced with challenge dynamic transmission interaction scheduling-related risk. The purpose this paper develop hierarchy risks from perspective contractor, analyze mechanism between risks. also aims further distinguish difference impact degree risks, provide reference...

Medium-voltage dc (MVdc) power distribution grid is a key link to build networks. In this article, novel input-series-output-parallel modular transformer (DCT) with the high-frequency-link (HFL) voltage buck-boost matching strategy proposed for MVdc grids application. The DCT composed of current-fed switched capacitor structure and corresponding dual-active-bridge converters, they need operate collaboratively achieve great property. Comparing traditional capacitor-based (SCDCT), most salient...

Due to low investment cost and high reliability, a new scheme called DR-HVDC (Diode Rectifier based HVDC) transmission was recently proposed for grid integration of large offshore wind farms. However, in this scheme, the application conventional control strategies stability operation face several challenges due uncontrollability DR. In paper, coordinated strategy farms using technology connect with onshore grid, is investigated. A novel on analysis DC current ability full-bridge-based...

A new grid-forming (GFM) high-voltage direct current (HVdc) rectifier, named flexible line-commutated converter (Flex-LCC), is proposed in this article to collect the power generated by large-scale islanded or weak-grid-supported renewable energy systems. The Flex-LCC uses a series-connected hybrid valve based on LCC and full-bridge modular multilevel (FBMMC), adopts control. As result, works as GFM rectifier retains same dc voltage carrying capacity, fault clearing, reversal functions an...

As a promising scheme for offshore wind power transmission, diode rectifier based high voltage dc has raised wide attention recently. But the design of DR-HVDC is mainly on traditional line commutated converter HVDC, which required large amount reactive and generated harmonics. In this paper, an enhanced proposed to reduce harmonic consumption by utilizing 24 pulses bridge transformer with decreased leakage reactance. Meanwhile, filter designed also introduced, can save space compensation....

The DR-HVDC (Diode rectifier-based HVDC) transmission topology was recently proposed for integration on large offshore wind farms due to its low investment cost and high reliability. To further reduce the investment, a DC collection based series-connected diode rectifiers (DR) is proposed, where no platform needed. However, units of (SCU) show coupling issues, such as overvoltage, energy curtailment, fault isolation. First, mechanism analyzed, suitable operation mode SCUs selected ensure...

With the growth of wind power and solar power, source clean transformation has become a feasible way for achieving carbon peak target. As hydropower resource-abundant province, Guizhou already built Wujiang river cascade plants. This paper introduces basic information provincial system geometrical renewable resource distribution characteristics, especially structure. Then, complementary characteristics are analyzed by different copula conjunction functions. structure generation expansion...

This paper investigated the characteristics of a novel type hybrid high voltage direct current (HVdc) converter, which is composed by line commutated converter series with source converter. The system and valve level control strategies are introduced, can provide ac support. A filter design scheme resonant filers for HVdc also proposed, decrease capacity reactive power compensation equipment without deteriorate harmonic characteristics. fluctuation caused transmitted variation will be...

Seafloor observation network provides limited opportunity for repair due to the atrocious weather on sea. As a result, reasonable reliability allocation methods are required assure is sufficiently reliable during expected years. In this thesis, betweenness used evaluating importance of component based binary search algorithm, and residual connectedness calculated according Monte Carlo method avoid combinatorial explosion. This applied meshed seafloor obtain satisfying backbone nodes....

To qualify the risk of extreme weather events for power supply security during long-term system transformation process, this paper proposes a probability evaluation method based on probabilistic production simulation. Firstly, internal relationship intensity and duration is depicted using copula function, influences are described guaranteed output ability coefficient, which can provide scenario basis Then, simulation proposed, includes typical-year events. Meanwhile, an index proposed to...

The ongoing energy revolution has led to the gradual replacement of traditional synchronous generators by renewable enecorresponding authorrgy. This transformation power generation mode reshapes system dynamics and poses many challenges reliable efficient grid operation. With continuous improvement penetration level represented wind in system, turbine will gradually become one main modes synchronization. In case coexistence multiple synchronization modes, mechanism whole be fundamentally...

Abstract In order to improve the performance of wind-induced vibration energy harvester (WIV-EH), bluff body and cantilever beam play a significant role when works. this paper, WIV-EH model is designed explore factors affecting capture efficiency. Optimal design body, five kinds set analyse influence shape on lift coefficient by COMSOL Multiphysics 6.0. According simulation results, D-shaped optimized changing scale ratio windward surface shape. beam, result shows that under same wind speed,...

The positive damping characteristic of a modular multilevel converter (MMC) is important for improving the stability an MMC based system. However, it difficult to optimize impedance characteristics by adjusting controller parameters, due complexity existing model. This paper investigates influence voltage-frequency(VF) on MMC, in which relationship between open loop controlled and VF established. Based proposed model, Non-dominated sorting genetic algorithm III (NSGA-III) used parameters...

With the high penetration of renewable energy in low voltage (LV) distribution networks, this paper proposes a coordinated operation strategy for photovoltaic (PV)-battery-load, which improves security and low-carbon economy, simultaneously. Firstly, mathematical models PV inverter reactive power support, battery capacity degradation three various consumer-side active loads, i.e. air conditioner (AC), water heater(WH) electric vehicle(EV) are built. Subsequently, optimal model aiming at...

This paper proposes an analytical model for the modular multilevel converter (MMC) based on theory of harmonic balance, which removes iteration process traditional models. The proposed considers dynamic interactions between modulation converters and passive elements in MMC. By transferring equations into frequency-domain as complex Fourier series, a steady-state is created with singular coefficients matrix. Then, through elimination all DC components model, coefficient matrix can be derived...