Despite the Smart Transformer's (ST) significant advantages in addressing system-level challenges, control-level issues, especially stability issues arising from increasing penetration of inverter-based renewables, remain crucial. Existing methods, like filter-based active damping and virtual impedance, have been explored literature to improve low voltage (LV) ST-fed grids. However, most these approaches are tailored specific concerns, lacking generality needed for comprehensive designs. To...

A novel three-phase dual-output T-type three-level converter (DO-T-TLC) topology is proposed in this article. The has the dc-link and two sets of ac voltage output terminals. DO-T-TLC introduced. Then, operating principle multiplexing switches available switching states are analyzed, including current path, phase level, blocking different states. disposition pulsewidth modulation scheme with dc offsets discussed detail, key problems under both common frequency operation modes, such as level...

Operation efficiency evaluation of distribution network could help to comprehend the power grid's real state, then improve decision-making level, and guide investment orientation in end. In context existing problems operation network, this paper puts forward a equipment model based on annual load duration curve, considering security economic requirements equipment. Based model, proposes an integral frame for including efficiency, hierarchy system balance degree, coordination degree. Due lack...

Recently, the penetration of photovoltaic (PV) power in system has being promoted rapidly. However, PV shows drastic fluctuation which presents great challenge to grid. Thus, how mitigate station needs be solved. Battery energy storage (BESS) is flexible charge/discharge and track power, also BESS integrated with fast response capability, so it well suited for smoothing fluctuations. At same time, should noted that relatively high price per unit size. So prolong its lifetime decrease average...

In recent years, the penetration of power electronic devices in system becomes higher. Grid-following converter, as a main category renewable energy interface grid, may trigger stability problems under some circumstances. However, with increasing complexity control strategy and grid structure, analysis difficult task due to heavy computational burden vague physical meaning high-order small-signal model. Numerical order reduction methods cannot offer clear interpretation, existing symbolic...

This paper summarized the operational characteristic of grid enterprises asset, and put forward key factor which reflected asset quality. Then it adjusted evaluation criteria different index, determine relative weights based on AHP, constructed an index system analysis quality, satisfied requirement domestic overseas comparative analysis. As a result, this offers support improving quality controlling risk for power enterprises.

In recent years, new energy supply (energy self-sufficiency) technology which can replace the traditional battery has become a hot topic in global research field of microelectronic devices. A low-frequency trapezoidal bow-shaped piezoelectric harvester (TBPEH) was proposed. The geometric model and finite element (FEM) were built. static analysis, modal analysis harmonic response TBPEH discussed by using Finite Element Analysis(FEA). Then rectangular harvester(RBPEH) compared with TBPEH....

It is important to assess the condition of cellulose insulation in transformer. However, taking paper samples from a transformer both impractical and destructive. In this paper, new method for assessment ageing oil impregnated pressboard based on frequency domain spectroscopy (FDS) was proposed. The FDS measurements were taken pressboards with five levels at moisture content 1.22%, 2.06%, 3.02% 3.87%. dielectric loss all calculated by tanδ (f) interpolation database which contains data 1%-4%...

The use of renewable energy has become a necessity to generate electricity, and is taking the place conventional coal-fired power, as it clear economic environmental benefits. purpose this paper quantify comprehensive benefits hydropower in reducing wind power fluctuation hybrid coal-fired/hydro/wind system. To achieve this, wind–hydropower generation system must be established, its complementary characteristic also illustrated based on resultant speed. Then, Institute Electrical Electronics...

The power quality and control capability of wind farms have an important impact on the safety economy system, which affects performance participating in system frequency modulation, peak shaving, reactive regulation voltage control. According to requirements farms, this paper analyses characteristics a typical farm connected Inner Mongolia grid, puts forward measures promote level capability, improve delivered ensure that meets regulation, increase consumption capacity stabilization grid.

In the new energy grid connected power generation system, accurately extracting synchronization signals such as frequency, phase and amplitude of voltage is basis for effective control. A design method phase-locked loop (PLL) in static coordinate system proposed demand synchronous signal detection under unbalanced harmonic conditions. This uses resonator to extract filter high frequency harmonics voltage, combines adaptive trap (ANF) positive negative sequence elimination (PNSC) complete...

In recent years, piezoelectric energy harvester which can replace the traditional battery supply has become a hot topic in global research field of microelectronic devices. Characteristics trapezoidal-loop (TLPEH) were analyzed through finite-element analysis. The output voltage density is 4.251V/cm2 when 0.1N force applied to free end ten-arm harvester. Comparisons resonant frequencies and voltages made. first order frequency could reach 15Hz by increasing number arms. Meanwhile, improved...

In order to improve the energy harvesting efficiency of piezoelectric cantilever beam (PCB) in environment. This paper presents a new type which is single-sided trapezoidal loop shaped PCB. By theory analysis, equivalent circuit model was established, resonant angular frequency inversely proportional length beam. Based on finite element analysis method, performance PCB and that rectangular are compared with same areas. The results show coupling voltage former larger, output power improved,...

The ambient energy harvesting based on piezoelectric has become an important subject in recent research publications. A new rectangular-loop harvester(RLPEH) is proposed. characteristic analyzed by the finite element analysis (FEA) which includes static analysis, modal and harmonic response analysis. results show that RLPEH could reduce resonant frequency improve output voltage. three order 18.6Hz, 40.8Hz 85.4Hz. voltage 42V under 3m/s2 of acceleration effective bandwidth 18.7Hz with above 10V.

Since breaking transmission lines has thousands of combinations for large power grid, it's difficult to find the best combination decrease short circuit level in a time. Sensitivity relationship between line outage and impedance change is aquatinted firstly this paper, then preliminary schemes selected according sensitivity. Index values factors including constraint condition, supply reliability other that mainly affect system stability are given using fuzzy comprehensive evaluation....

Wind power forecast (WPF) system has been an indispensable component for a wind farm connected to grid, and combination approach proved effectiveness improve the robustness accuracy of forecasting results. Most existing approaches fix weights selected sub-models ignore performance variation under different meteorological conditions. This paper proposes dynamical weighted considering similarity short-term WPF. Firstly, three consisting gate recurrent unit, light gradient boosting machine...

As an important part of smart grid development strategy, on-line monitoring system transmission lines has the characteristics informationization, networking and automation. With continuous expansion power scale, there are more inspection maintenance work under complex terrain conditions. Through highly sharing multi-source heterogeneous information data mining, intelligent management line operation maintenance, safety early warning their surrounding environment health status evaluation...

The randomness and fluctuation of photovoltaic (PV) power brings new challenges to system operation. Accurate PV generation prediction is critical dispatch. can provide reference for dispatching, which conducive the safe stable operation grid. Since a continuous process, variation at each moment related meteorological characteristics or information historical moment. This paper applies long short-term memory network (LSTM) forecast results different input features are compared analyzed. show...

The interaction between the distributed energy resources (DERs) inverter and smart transformer (ST) could trigger harmonic oscillation problem of ST-fed Grid. To solve problem, this paper proposes a second-order digital filter-based stabilized control strategy to enhance stability grid. Then, analyzing from perspective zeros poles ST output impedance, design criterion is proposed based on relationship filter characteristic roots system. Finally, effectiveness verified by experiment.

To decrease short-circuit current, adjusting the power network operation by breaking transmission lines is most economic and convenient measure. For large grid, has thousands of combinations, so it's very difficult to find best combination in a short time. Firstly, this paper formulated sensitivity relationship between line outage impedance change. Then preliminary combinations schemes were selected according sensitivity. Index values factors given using fuzzy control evaluation. Finally,...

In order to solve the problem of large switching loss, voltage peak and poor stability in DC-DC transform high frequency isolation inverter, a new inverter circuit topology, which is combined with parallel resonant traditional converter, proposed. The can realize zero opening power device, soft turn off body diode rectifier diode, so as eliminate switch device reduce loss inverter. working process principle various devices are introduced detail, equivalent model circuit, influence resonance...