A novel soft-switching hybrid converter combining the phase-shift full-bridge (FB) and half-bridge (HB) LLC resonant converters' configuration with shared zero-voltage switching (ZVS) lagging leg is proposed to ensure switches in operating at fully ZVS condition. The dual outputs of FB-HB are connected series whole dc-output voltage can be regulated by PWM control within desired range. circuit used secondary side FB reset primary current during freewheeling period, as well transfer more...

A particle swarm optimization (PSO) algorithm-based staircase modulation strategy for modular multilevel converters (MMC) is proposed. To reduce switching losses and device stress, the method has been adopted in high-voltage high-power energy conversion applications. In particular, selection of appropriate iterative initial values angles a significant step to realize modulated MMC. The proposed able find optimum angles, while it advantages global quadratic convergence, which benefit from PSO...

The open-circuit fault detection and localization (FDL) technique can improve the reliability of modular multilevel converter (MMC). However, conventional software-based FDL methods usually have a heavy computation burden or limited speed. This article proposes simplified fast approach for grid-connected MMC. First, errors between measured state variables (the output current circulating current) their estimated values are calculated. By comparing these with threshold values, switch not only...

A novel single-phase flyback inverter for photovoltaic applications is proposed to achieve low-frequency ripple current reduction on the DC busbar and draw sinusoidal into AC grid. Based capacitive idling techniques, circuit topology derived from a single-ended primary-inductance converter two-switch obtain soft-switching operation all of active switches. Compared with buck-boost other topologies module systems, no extra switches are used in realise both enhanced power decoupling only four...

In this paper, a new cascade active-front-end converter based on dual-boost/buck converters is proposed for an intelligent universal transformer (IUT), which allows adjusting the power factor to control both active and reactive powers between medium low voltage levels. Compared traditional H-bridge converter, it has much enhanced system reliability owing no shoot-through problems lower switching loss with help of using MOSFETs. addition, unified scheme active-reactive individual balancing...

The model predictive control (MPC) methods have been widely applied due to the fast dynamic performance and multiple targets. However, they show certain limits when multilevel converters, such as unfixed switching frequency, large computation burden, complex weighting factors selection. This article proposes a novel modulated MPC (M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> PC) method for cascaded H-bridge (CHB) converter-based...

A modulation reconfiguration based fault-tolerant method is proposed for the modular multilevel converter (MMC) system. practical to reconfigure reference sine wave from point of view that output line-to-line voltages should be guaranteed well regulated and not vary. Voltage balancing sub-module capacitors achieved while using carrier rotation algorithm multicarrier pulse width modulation. Experimental results obtained laboratory system verified validity reliability control in MMC application.

With the high penetration of power electronic loads in grid, stability static synchronous compensator (STATCOM) devices is greatly challenged. However, conventional control methods for modular multilevel converter (MMC) based STATCOM only consider with small signal disturbances. This article proposes a novel dual-layer back-stepping (BSC) MMC-based STATCOM. In first layer, BSC aims to regulate sum capacitor energy and reactive output current. second circulating Therefore, proposed method...

To achieve five-level pulse width modulation (PWM) operation, a single-phase voltage-source inverter is proposed. A shunt active power filter based on the proposed implemented to harmonics elimination, reactive compensation and dc-link voltage regulation. Whereas eight switches are used in conventional inverter, only six needed inverter. The achieves PWM operation without clamping diodes flying capacitors. functions as controllable current source supply necessary for compensating losses,...

In this paper, a family of new step-up series-parallel dual resonant switched-capacitor converters (SP-DRSCs) is proposed to extend the conversion ratio for high applications. The feature wide gain range, continuously adjustable, and enhanced light-load voltage regulation. All flying capacitors operate in resonance, eliminating transient current spikes charge sharing losses. Thus, zero-current-switching (ZCS) turn-on all transistors ZCS turn-off diodes are achieved. A comprehensive analysis...

In this article, a step-down switched-capacitor converter (SCC) and step-up SCC with an integrated passive regenerative snubber (PRS) are proposed based on the Cuk dual resonance core (DRC). The members of DRC family overcome barrier for SCCs to achieve continuous output voltage regulation. One remaining challenge is turn-off spikes oscillations during switch transient that cause stress power loss transistor diode. PRS eliminates across diode process. Moreover, zero switching (ZVS) turn-on...

A novel capacitor voltage balancing scheme for modular multilevel cascade converter-double-star chopper-cells (MMCC-DSCC)-based STATCOM is proposed in this paper. Compared with the conventional software methods, has three main advantages. First, only six sensors are needed, and other have been removed. Then, control framework can be simple without sort select process, or some loops. Additional delay process caused by sampling signals transmission also mitigated. Finally, faster speed...

Model predictive control (MPC) method has been recognized as one of the most promising technologies for modular multilevel converter (MMC) due to fast dynamic response and its simple realization. However, conventional finite set (FCS) MPC methods MMC are facing some challenges, such high computation burden, poor steady-state performance, dependence on weighting factors, variable switching frequency. In order solve these problems, a novel sliding-discrete-control-set (SDCS) modulated (MMPC)...

Bidirectional LLC resonant DC-DC transformer (DCT) has the advantages of converter in achieving high efficiency and power density, which features soft switching regardless direction flow. Due to existence large filter capacitor, inrush current is inevitable starting process. A improved start control strategy based on phase shift proposed by analysis gain characteristics DCT. It can charge output capacitor gradually, build up voltage smoothly eliminate effectively. The performance scheme...

The rational power sharing among different interface converters should be determined by the converter capacity. In order to guarantee that each operates at ideal condition, considering radial and mesh configuration, a modified strategy for load accuracy enhancement in droop-controlled DC microgrid is proposed this paper. Two compensating terms which include averaging output control voltage of neighboring are employed. Since only information used, complexity communication network can reduced....

In this paper, a two-stage battery energy storage system (BESS) is implemented to enhance the operation condition of conventional systems in microgrid. Particularly, designed BESS composed two stages, i.e., Stage I: integration dispersed units (ESUs) using parallel DC/DC converters, and II: aggregated ESUs grid-connected operation. Different from consisting management (BMS) power conditioning (PCS), developed architecture enables additional control flexibility balancing state-of-charge (SoC)...

LCL filters are widely used in public interfaces of active power (APF) and grids due to their strong harmonic attenuation capabilities the miniaturization passive components. In order make interface filter have low damping loss high filtering effect, this paper chooses an improved commonly APF for parameter design. Theoretical analysis simulation comparison performance with conventional LCL-type performed. The experimental results prove feasibility superiority design method.

The operation capability of the modular multilevel converter (MMC)-based static synchronous compensator (STATCOM) is limited under submodule (SM) failures. When running in STATCOM mode, floating dc-link voltage MMC adjustable. Therefore, this article proposes a novel fault-tolerant approach to enhance severe SM First, dynamically regulated failures, where capacitor voltages all SMs are slightly increased. modulation ranges faulty and healthy phases can be enlarged, even stress distribution...

As the wind power penetration in system is increasing rapidly, new grid connection codes for turbines are established. Low voltage ride through (LVRT) ability of required order to ensure stability and improve generators. The characteristics fixed speed generators described, a topology based on TSC induction generator LVRT capability its control principle proposed this paper. Comparisons turbine transient performances equipped with without during after unbalanced fault evaluated. Simulation...

With the increasing popularity of photovoitaic power generation, traditional supply mode in future will gradually evolve into balance between production and sales community. Users microgrid also play role producer, seller consumer. In view this mode, paper first introduces application blockchain technology field energy Internet, illustrates necessity introducing limitations current based on research results. Then, made a concise comprehensive introduction to technology, proposed P2P trading...

With the wide application of microgrid system, fluctuation and randomness are characteristics distributed generation output. The traditional energy management system can’t meet requirements to ensure security stability grid. is great significance stable operation power In order obtain higher economic benefits pay less environmental costs, reasonable scheduling various sources able achieve this goal. article, including studied. objective function includes objective. model considered as a...

To explore the clustered voltage balancing mechanism of cascaded H-bridge static synchronous compensator (STATCOM), this paper analyzes causes unbalanced voltage. The negative-sequence current caused by compensation reactive power or detection and control errors zero-sequence drift STATCOM neutral point contribute to On basis, proposes a strategy inject simultaneously. injection may cause asymmetry in grid, has relatively limited ability voltages. proposed can not only generate faster...

Using rotor d-p model as a start point, this paper analyses the mathematical for brushless doubly-fed machine (BDFM) based on double synchronous reference frame. And, characteristics of BDFM, new type power control system is designed by applying flux oriented vector transformation technology. This realizes decoupling active and reactive variable-speed constant-frequency (VSCF) generator using windings to carry out AC excitation. Meanwhile, because structure complex parameters are variable...

A novel double-loop feedback control strategy of DVR based on proportional-resonant is proposed. Compared with the traditional proportional-integral (PI) controller, controller applied to output compensation voltage DVR, can achieve tracking zero static error for reference signals voltage. Based frequency characteristic analysis system in discrete domain introducing delay analyzed. Analyses show that current inner loop using a simple proportional has reliable stability, and acting outer...