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This paper proposes a hybrid-switch three-phase current source rectifier (CSR) solution, which employs only one silicon carbide (SiC) switch and six traditional silicon (Si) switches. The corresponding hierarchical discontinuous pulse width modulation (HDPWM) strategy for the proposed CSR is also presented, which uses two parallel carrier-based discontinuous PWM branches to perform differentiated modulation operations on Si and SiC devices to endow the Si switches with zero current switching capability and conveniently make full use of the high-speed and low-loss advantages of SiC devices. Consequently, the proposed hybrid-switch CSR with HDPWM can even work as a full SiC device-switching converter with relatively lower costs, thus addressing the critical needs of efficiency promotion of CSR applications. MATLAB simulations and experimental verifications were conducted to verify the performance of the proposed CSR solution. [ABSTRACT FROM AUTHOR]

Nano-opto-electro-mechanical systems (NOEMS), considered as new platforms to study electronic and mechanical freedoms in the field of nanophotonics, have gained rapid progress in recent years. NOEMS offer exciting opportunities to manipulate information carriers using optical, electrical, and mechanical degrees of freedom, where the flow of light, dynamics of electrons, and mechanical vibration modes can be explored in both classical and quantum domains. By exploiting NOEMS concepts and technologies, high speed and low-power consumption switches, high-efficiency microwave-optical conversion devices, and multiple quantum information processing functions can be implemented through on-chip integration. This review will introduce the principles of NOEMS, summarize the recent developments, and important achievements, and give a prospect for the further applications and developments in this field.

The vacuum interrupter is widely used due to the advantages of no arc-extinguishing medium and high insulation strength. However, the arc voltage generated by the commonly used CuCr contacts is low. In hybrid DC circuit breakers (DCCB), hybrid automatic transfer switches (ATS), medium voltage compound switches and other fields, it is difficult to rely on vacuum arc to complete natural commutation, which restricts the development of hybrid switches. In order to understand the current commutation process deeply, the influence of internal and external factors on the current commutation is analyzed by experiments. The coupling mathematical model of arc-commutated branch is established. The criterion for the success of current commutation is summarized. The parameters of the arc model are reconstructed through repeated breaking experiments to explore the influence of internal factors on the arc characteristics. Based on this, the influence law of arc current, contacts gap and transverse magnetic field (TMF) is analyzed. An acceleration method of current commutation is proposed. A prototype for accelerating experiments with an electromagnetic repulsion mechanism and TMF is developed. The commutated branch equivalent to practical applications is built. The experimental results show that the commutation time is effectively shortened and meets the requirements of practical applications through the acceleration method, which provides new thought for the development of hybrid switches.

The article presents a new generation of ultra-fast hybrid switching systems (USH) for reliable, ultra-fast protection of various medium and low voltage DC systems (MVDC and LVDC). The DC switch-off takes place in a vacuum chamber (VC) cooperating with a semiconductor module using current commutation of natural or forced type. Against the background of the current state of science and technology, the paper depicts the basic scopes of USH applications and their particular suitability for operation in high magnetic energy DC circuits. In the case of DC system failures, this magnetic energy should be dissipated outside the system as soon as possible. Usually, magnetic blow-out switches (MBOS) with relatively low operating speed are used for this purpose. The article describes the theoretical basis and principles of construction of two types of novel USH systems: a direct current switching system (DCSS) and a direct current ultra-fast hybrid modular switch (DCU-HM). The DCSS family is designed for quench protection of superconducting electromagnets’ coils in all areas of application. The DCU-HM family is designed for the protection of all systems or vehicles of DC electrical traction and for related industrial applications. The conducted comparative analysis of the effectiveness of USH with respect to MBOS shows clear technical advantages of the new generation switching systems over MBOS. List of abbreviations used in the article is provided at the end.

The article presents a new generation of ultra-fast hybrid switching systems (USH) for reliable, ultra-fast protection of various medium and low voltage DC systems (MVDC and LVDC). The DC switch-off takes place in a vacuum chamber (VC) cooperating with a semiconductor module using current commutation of natural or forced type. Against the background of the current state of science and technology, the paper depicts the basic scopes of USH applications and their particular suitability for operation in high magnetic energy DC circuits. In the case of DC system failures, this magnetic energy should be dissipated outside the system as soon as possible. Usually, magnetic blow-out switches (MBOS) with relatively low operating speed are used for this purpose. The article describes the theoretical basis and principles of construction of two types of novel USH systems: a direct current switching system (DCSS) and a direct current ultra-fast hybrid modular switch (DCU-HM). The DCSS family is designed for quench protection of superconducting electromagnets' coils in all areas of application. The DCU-HM family is designed for the protection of all systems or vehicles of DC electrical traction and for related industrial applications. The conducted comparative analysis of the effectiveness of USH with respect to MBOS shows clear technical advantages of the new generation switching systems over MBOS. List of abbreviations used in the article is provided at the end. [ABSTRACT FROM AUTHOR]

We design and experimentally demonstrate scalable $2\times2$ , $4\times4$ and $8\times8$ silicon photonic (SiPh) thermo-optic switch exhibiting low loss, low crosstalk, low power penalty, and BER below 10−10 for payload data transmission. Less than 3.13 dB insertion loss (IL) and approximately 20.5 dB crosstalk is measured in the $8\times8$ SiPh banyan switch with thermal phase shifters. We also report on a semiconductor optical amplifier (SOA) in an indium phosphide (InP) technology platform with 25 dB gain and 7 dB noise figure enabling to transmit optical signals with large OSNR. Combining SiPh and InP technologies, we propose a lossless hybrid switch matrix with distributed SOA-based gain capable of transmitting data with near zero loss and low crosstalk over a large switching matrix. In hybrid SiPh/InP switches, the SOA gain compensates for the SiPh switch loss at the cost of amplified spontaneous emission (ASE) noise but mitigated by bandpass optical filters. Lower IL from the SiPh switch requires less gain from the SOAs leading to less OSNR degradation. Experimentally validated building blocks confirmed scalability up to $64\times64$ in SiPh-InP hybrid platform. [ABSTRACT FROM AUTHOR]

We report on possible 75% lower energy consumption for packet transport in data center networks replacing electronic with hybrid optical packet switching (optical switches with a shared electronic buffer) combined with the enhanced transmission control protocol. [ABSTRACT FROM AUTHOR]

Optical packet switching (OPS) has long promised performance and energy consumption improvements by doing away with optical-to-electronic conversions required by electronic packet switching; however, not having practical optical buffers makes OPS highly vulnerable to contention. This study reports on the possible and plausible use of OPS technology on datacenter networks by coupling two concepts: optical switches with shared electronic buffers, also known as hybrid switches, and the introduction of TCP congestion control algorithms (CCAs) to control transport of optical packets. The stop-and-wait (SAW) and the modified additive increase multiple decrease (mAIMD) CCAs families are reviewed. For SAW, a basic version and a modified one—stop-and-wait-longer, adapted for hybrid switches—are analyzed. As for mAIMD, a TCP selective acknowledgment (SACK) implementation and its simplified modification TCP mSACK are studied. It is successfully shown that these algorithms paired with the use of shared electronic buffers in hybrid switches significantly outperform bufferless all-optical switches and reach the level of all-electronic switches in datacenters and local area networks in terms of network throughput. [ABSTRACT FROM AUTHOR]

Two carrier-based unipolar-sinusoidal pulse width modulation (SPWM)-oriented modulation techniques for an isolated bidirectional dc–ac converter are proposed, compared, and validated in this paper. The dc–ac converter is composed of a full-bridge (FB) inverter cascaded with a cycloconverter through a high-frequency transformer. Both modulation techniques proposed in this paper can realize zero-voltage switching (ZVS) for the FB inverter and zero-current switching or ZVS for the cycloconverter in all load range, and are able to suppress the voltage spikes introduced by the transformer leakage inductance as well. In order to increase the converter efficiency and power density, we propose to utilize SiC MOSFETs for the converter. The first modulation technique enables the utilization of Si-SiC hybrid switches with no synchronous rectification (SR), for the purpose of lowering the converter cost. The second modulation technique requires all switches to be SiC MOSFETs, but with SR, which increases the converter efficiency. A 400-V dc to 240-V ac 1.2-kW prototype has been developed to validate the effectiveness and performance of the proposed carrier-based unipolar-SPWM-oriented modulation techniques. [ABSTRACT FROM PUBLISHER]

Hybrid switches configured by paralleling Silicon (Si) Insulated Gate Bipolar Transistors (IGBT) and Silicon Carbide (SiC) Metal-Oxide Semiconductor Field-Effect Transistors (MOSFET) have been verified to be a high-efficiency cost-effective device concept. In this paper, a current-dependent switching strategy is introduced and implemented to further improve the performance of Si/SiC hybrid switches. This proposed switching strategy is based on a comprehensive consideration of reducing device losses, reliable operation, and overload capability. Based on the utilization of such Si/SiC hybrid switches and the proposed switching strategy, a 15-kW single-phase H-bridge inverter prototype was implemented and tested in the laboratory. Simulation and experimental results are given to verify the performance of the hybrid switches and the new switching strategy. [ABSTRACT FROM PUBLISHER]

Optical switching can be performed by using optical amplifiers combined with a passive waveguiding network. Recently, most of the effort in optical amplifier switch modules have been focused on monolithic switches in which the entire device is fabricated on an InP substrate together with the semiconductor optical amplifiers (SOA's). In this paper, we investigate the use of SOA's with passive polymer waveguides to make hybrid switches of varying sizes. The optical amplifiers serve dual purposes, gating the signal and amplifying the signal. Amplification is needed in order to offset the losses associated with the passive waveguide elements as well as the losses from component misalignments in the switch module. Our analysis finds the largest switch module size that can be made with the architecture used. We also calculate the maximum number of switch modules which can be cascaded in order to retain a bit-error rate (BER) under 10-9 [ABSTRACT FROM PUBLISHER]