In recent years, modular multilevel converters (MMCs) are very popular in medium/high-voltage motor drive systems and high-voltage direct-current (HVDC) applications. The conventional model predictive control (MPC) strategies for the MMC not practical due to their substantial calculation requirements, especially under high number of voltage levels. To solve this problem, a fast MPC strategy combined with submodule (SM)-voltage sorting balancing method is proposed based on discrete...

Modular multilevel converters (MMCs) have been widely used in recent years due to their superior advantages medium/high-voltage applications. The finite control set model predictive (FCS-MPC) has shown high dynamic responses for the of MMC. However, with existing FCS-MPC algorithms, steady-state performances are degraded irregular pulse patterns, especially under unbalanced grid conditions. In this paper, based on discrete state-space MMC, a modulated MPC (M2PC) algorithm is proposed...

To solve the issue of exponentially increasing computational burden finite control set model predictive (FCS-MPC) for multilevel converters, a fast MPC scheme cascaded H-bridge STATCOM is presented. The proposed approach consists three steps. First, with partially stratified optimization approach, multiobjective programming divided into two suboptimization problems, i.e., current-control and voltage-balancing MPC. Second, dynamic algorithm Third, mixed algorithm, which combines greedy (0-1...

Adapting to climate change and controlling carbon emissions have emerged as significant challenges faced by the international community. The high-quality pedestrian space system of TOD blocks, an important means for reduction sink increase in cities, showcases effect green intensification low-carbon sustainable urban development. In this study, combining research on block creation microclimate, focusing technical process three stages pre-treatment, core calculation, post-treatment,...

As an important indicator of the level urban economic development and quality residents’ lives, housing prices are affected by various factors, such as spatial distribution market, characteristics neighborhoods, location conditions. This paper summarizes in Qingdao using GIS, analyzing characteristics, combines these with Geographically Weighted Regression (GWR) model to explore influence community attributes, location, transportation, peripheral facilities on residential prices. The results...

This work experimentally implements a physical reservoir computing system using back-end-of-line SiC thin film based memristor to achieve pattern recognition with high accuracy.

As indispensable elements of public space in the city, metro stations and parks have dual characteristics “node” “place”. Based on “node–place” theoretical framework, spatial evaluation detailed classification Qingdao station is carried out by integrating ArcGIS technology diversified data sources. On this basis, an innovative coupling model constructed, which takes into account carrying capacity, park accessibility, land use degree, other factors, while evaluating economic environmental...

Long-range ordered supercrystals (SCs) built up by colloidal nanocrystals (NCs) represent a class of novel metamaterials with unique collective properties. While great attention has been paid to the ligand-controlled assembly NCs, contribution inorganic core is considered limited because weak core-core interactions. Here, we report spontaneous Ag2S quantum dots (QDs) into three-dimensional SCs in solution, driven pronounced dipole-dipole Dielectric spectroscopy shows large permanent dipole...

With the development of modern cities, people’s living environment requirements are constantly improving. Urban villages in Qingdao area, as a key area for urban renewal, affected by sea breeze and have warm humid climate summer, which, together with their problems irrational layout poor ventilation outdoor public space, seriously reduce quality space. In order to improve comfort village residents, this study uses CFD numerical simulation SPSS25 software analysis investigate coupled...

Urban sprawl and excessive reliance on motorization have led to many urban problems. The balance of supply demand in the real estate market, as well price fluctuations, also face challenges. rail transit not only alleviates traffic congestion air pollution, but significantly reduces residents’ commuting time, broadens accessibility, reshapes decision-making basis for residents when choosing residential locations. This study takes 1st, 2nd, 3rd, 4th, 8th, 11th, 13th metro lines that been...

In this paper, a high-performance 22 MW/27 MVA test bench using pumpback topology is introduced for testing electrical machines. It proposes cost-effective concept that works reliably even with weak grid. A paralleling of two three-level integrated gate-commutated thyristor (IGCT) converters presented. I generates five-level pulse pattern low harmonic distortion at 600-Hz carrier frequency and 80-Hz load frequency. The selected magnetic device minimizes the circulating current, which ensures...

Unity grid power factor is essential for the indirect matrix converter (IMC) applications due to grid-friendly requirement. The existing closed-loop control methods usually consist of complex structures, resulting in high requirements both hardware and software aspects. In this paper, a low-cost phase-angle compensation method proposed reduce costs. Based on modeling IMC, influences from system parameters angle are analyzed. Then, virtual adaptive resistance model denoted calculated with...

A virtual vector based modulated model predictive control (VV-M2PC) strategy is proposed for the indirect matrix converters (IMCs) in this article. Compared with conventional M2PC, VV-M2PC constructs and utilizes new vectors to reduce current errors. Besides, implementation feasibility discussed detail. The comparative simulation experimental results on an IMC prototype verify that steady-state performance can be improved under without affecting dynamic-state increasing computational burden.

In this paper, an over view of damping method for three-phase voltage-source PWM rectifier with LCL filter is given. The traditional connected to supply network L filter. Increasing the value can attenuate ripple current around switch frequency which fulfills standards but it will decrease response speed and stability system. An more effective reduce harmonic distortion at lower than However bring problem. One solution use a resistor in series or parallel capacitor called "passive damping"....

Unity grid power factor (GPF) is essential for the indirect matrix converter (IMC) applications to satisfy grid-friendly requirement. The existing unity GPF control strategies usually consist of high-complexity structures, resulting in difficult parameter adjustments and high-speed processor requirements. In this paper, a low-complexity input current (LCICC) strategy proposed IMC operating at GPF. Unlike conventional designed $d$ -$q$ synchronous coordinate frame, LCICC set up $\alpha $...

The static synchronous compensator(STATCOM) using power electronics as a shunt device of the Flexible AC Transmission Systems (FACTS) is attracting an increasing interest in system research and electric utilities. This paper proposes novel multi-level structure topology with zigzag transformer for three-level inverter used STATCOM. Moreover, selective harmonic elimination pulsewidth modulation (SHEPWM) applied to reduce switching frequency while restraining harmonics at same time. Simulation...

The precharge of the capacitors in sub-modules is essential to normal operation modular multilevel converter. Based on analysis topology and theory MMC. This paper analyzed process uncontrolled charging method, then explained reason why capacitor voltage can’t be charged desired value. To solve this problem, a selection method proposed relative discussed. By not only number which needed at same time can reduced, but also three phase time. Depend could rose feasibility strategy verified by...

The traditional intelligent algorithms for the selected harmonic elimination pulse-width modulation (SHEPWM) of multilevel converters provide low convergent rate and accuracy solutions when solving quarter-wave symmetry nonlinear equations. To obviate this problem obtain a better modulating performance, an improved imperialist competition algorithm is proposed. proposed enhances global search ability by using moving imperialists. Also, novel type particles, named independent countries, are...

This paper presents air-gap flux-oriented vector control based on pseudo 12-pulse noncirculating current cycloconverter-fed dual stator winding synchronous motor (DSSM) drive for high power and low speed application. The salient pole with damper model is discussed. feedforward decoupling method proportional-integral (PI) separate controller of regulation has been used. DSSM mine hoist implemented using a multiprocessor digital controller. Experimental results are presented.

MicroRNAs (miRNAs) have been regarded as biomarkers for early-stage diagnosis of cancer. Due to their short length, low abundance, and very similar sequences, an attractive approach that is ultrasensitive label-free extremely demanded. Here we report the design a novel semiconducting silicon nanowire field-effect transistor (SiNW-FET) biosensor array real-time detection miR-21. Optical lithography anisotropic self-stop etching were employed guarantee cost batch production SiNWs. The working...