This paper describes a modified phase-shifted carrier-based pulsewidth-modulation (PSC-PWM) scheme for modular multilevel converters (MMC). In order to reduce the average device switching frequency, reduced switching-frequency (RSF) voltage balancing algorithm is developed. also proposes circulating current suppressing controller (CCSC) minimize inner in an MMC. Based on double line-frequency, negative-sequence rotational frame, three-phase alternative currents are decomposed into two dc...

The modular multilevel converter (MMC) is an emerging and attractive topology for the high-voltage direct-current (HVDC) transmission system. This paper presents a generalized mathematical model MMC in HVDC applications under balanced unbalanced grid conditions. dynamics of positive-, negative-, zero-sequence components are derived from model. Then, dual current control scheme with positive- negative-sequence controllers applied to MMC. power controller eliminate other one...

This paper applies nearest level control (NLC) to the modular multilevel converter (MMC). Since there are a number of submodules (SMs) in high-voltage applications MMC and all SM voltages required be measured sorted, if uniform sampling frequency is not high enough, will triggered as quickly possible. Thus, converter-output voltage levels harmonics affected. A method systematically analyze presented, considering frequency. In order select proper frequency, two critical values, which...

The modular multilevel converter (MMC) with half-bridge submodules (SMs) is the most promising technology for high-voltage direct current (HVDC) grids, but it lacks dc fault clearance capability. There are two main methods to handle dc-side short-circuit fault. One employ SMs that have capability, power losses high and has be blocked during clearance. other hybrid HVDC breakers. breaker capable of interrupting within 5 ms, this not cost effective, especially in meshed grids. In paper, an...

There are second-order harmonics in the dc voltage and current when MMC-HVDC system is under unbalanced grid conditions, even if negative-sequence controller employed. This paper presents a supplementary ripple suppressing (DCVRSC) to eliminate harmonic of system. The instantaneous power converter arm phase unit indicates that there zero-sequence double-line frequency components three-phase voltages ac an fault. Since cannot be offset by each other, they lead current. DCVRSC developed...

Abstract Memristors have recently become powerful competitors toward artificial synapses and neuromorphic computation, arising from their structural electrical similarity to biological neurons. From the diversity of materials, numerous organic inorganic materials proven exhibit great potential in application memristors. Herein, this work focuses on a class memristors based frameworks (OFs) pay attention most advanced experimental demonstrations. First, typical device structures memristive...

This paper describes two distinctive functions of the arm inductor in modular multilevel converters (MMC): suppressing circulating current and limiting fault rise rate. Based on equality instantaneous power, characteristics are analyzed demonstrated that it flows through three phase converter negative sequence at double-fundamental frequency. The relationship between amplitude value is discussed, first principle to design parameters proposed. second based calculation rates, with different...

A design method to lay emphasis on a differential geometric approach for decentralized nonlinear optimal excitation control of multimachine power systems is suggested in this paper. The law achieved implemented via purely local measurements. Moreover, it independent the parameters networks. Simulations are performed six-machine system. It has been demonstrated that could adapt conditions under large disturbances. Besides, paper verified sense LQR principle linearized system equivalent an...

This paper studies the techniques for modeling modular multilevel converter (MMC) based multi-terminal HVDC (MTDC) systems in electromechanical transient mode. Firstly, mathematical model of MMC and its corresponding equivalent circuit are established, which similar to those two level converters. Then, a power flow calculation method AC/DC containing MMC-MTDC is developed. Two dynamic models developed paper. One detailed model, taking into account AC side circuit, inner controllers,...

This paper analyzes the dc line fault transient stability characteristics of AC/DC power systems with three different modular multilevel converter based high voltage direct current (MMC-HVDC) configurations. The first configuration is half bridge sub-module MMC (H-MMC) HVDC configuration, which clears faults by tripping ac circuit breakers. clamp double (CDSM) (C-MMC) clearance ability constitutes second configuration. A line-commutated (LCC) and hybrid ability, named LCC-diode-MMC...

A circulating current suppressing controller (CCSC) is presented to eliminate the inner balancing currents in modular multilevel converter (MMC). Based on double-fundamental-frequency, negative-sequence rotational frame, three phase alternative are decomposed two DC components, and limited a low level by pair of proportional integral controllers. This control strategy does not affect MMC outer dynamics ac side. Simulation results based PSCAD/EMTDC demonstrated effect proposed CCSC proved...

This paper focuses on a bipolar modular multilevel converter (MMC)-based HVDC system, which is suitable for bulk power overhead line transmission. In this topology, each pole consists of several basic units (BCUs) in series or parallel, and the BCU recently developed MMC adopting clamp double submodules (CDSM-MMC). Between positive negative neutral bus connected to ground electrode. To manage distribution among BCU, three control layers hierarchy are designed. Based equivalent circuit...

The modular multilevel converter (MMC) is a new kind of voltage source (VSC) with high number levels and considered to be suitable for HVDC transmission. Based on circuit configuration operation mechanism, this paper presents an mathematical model MMC. Then the vector control strategy widely used in two-level VSC applied Due structure cascaded connections, very obtained by MMC applications, which nearest level modulation (NLM) become feasible. A combination NLM optimized capacitor balancing...

Considering the synthetical effects of ac system and dc system, this paper proposes two novel indexes, dynamic redundancy utilization ratio submodules. On basis, nearest level control is applied as modulation method an optimized strategy based on for modular multilevel converter (MMC) proposed. One main innovations that reference value capacitor voltage derived according to maximum output each arm safety margin which can be adjusted artificially. Unlike previous strategies, dynamically,...

The hybrid cascaded multilevel converter is a newly introduced voltage-source with dc blocking capability. It has two key parts, that is, the director switch (DS) made of insulated-gate bipolar transistors in series and wave-shaping circuit (WSC) containing stacks full-bridge submodules (FSMs). This paper focuses on modulation schemes DSs WSCs. First, to reduce switching losses DSs, novel asymmetrical square-wave at very low frequency proposed, energy flow WSC under this analyzed. Second,...

The newly developed modular multilevel converter based on a clamp double submodule (CDSM), namely, C-MMC, has been identified as good solution for high-voltage direct-current (HVDC) applications, due to its inherent unique dc fault blocking capability. This paper presents self-start control strategy the C-MMC-based HVDC link. equivalent charging circuit uncontrolled precharging stage is derived and behaviors of CDSM are investigated. In addition, selection current-limiting resistor...

This paper describes a modified phase-shifted carrier-based pulsewidth-modulation (PSC-PWM) scheme for modular multilevel converters (MMC). In order to reduce the average device switching frequency, reduced switching-frequency (RSF) voltage balancing algorithm is developed. also proposes circulating current suppressing controller (CCSC) minimize inner in an MMC. Based on double line-frequency, negative-sequence rotational frame, three-phase alternative currents are decomposed into two dc...

This paper evaluates the converter power losses of modular multilevel based HVDC systems (MMC-HVDC). A junction temperature feedback method is proposed in order to estimate more accurately. Based on data provided by manufacture, characteristic semiconductor device acquired. Both switching and conduction are calculated with real-time voltage current waveforms, which derived from detailed PSCAD/EMTDC model. Thermal circuit model applied average temperatures semiconductors. The valve different...

Through-strata-via (TSV) technology emerges as the key to enable 3D integration. In this paper, electromagnetic field solvers and analytic circuit simulators are employed study model TSV electrical performance. Performance of simple structure is analyzed in time domain frequency domain. impacts various configurations evaluated. A broadband equivalent developed for design. Key results include: 1) excellent TDR/TDT behavior wide open eye diagram with ultra low bit error rate can be achieved a...

Being one of the most attractive 3-D integration solutions, through-silicon-vias (TSVs) electrically connect multiple strata integrated circuits and/or devices in a vertical fashion. This paper examines electrical performance coaxial TSV, which is new configuration that offers better signal integrity than other TSV structures. Various processing materials and physical geometries are considered for designs. The full-wave extraction empirical calculations show good agreement passive elements...

This paper presents a new method based on piecewise analytical formulas to evaluate the valve losses of modular multilevel converter high-voltage direct current (MMC-HVDC) transmission systems. According generating mechanism, total MMC are divided into three parts: 1) conduction losses; 2) essential switching and 3) additional losses. Due large number arm submodules in MMC-HVDC links, harmonic components voltages currents omitted. Therefore, can be precisely represented by formulas. The...