Simulation of the 5G Communication Link Between Solar Micro-Inverters and SCADA System

Energy crises and the growth of the energy demand have increased the interest in utilizing unconventional power sources. Thus, renewable energy sources have become a topic of interest to mitigate rising energy concerns and cope with increased electricity demand. With remarkable merits including cleanness and abundance, photovoltaic (PV) solar energy systems are a key to solving these issues. The employed inverters should effectively utilize the maximum available power from the PV solar system and transfer this power to the utility grid without posing any further limitations. However, the unequal power generation of different PV systems caused by partial shading (PS) and other PV panel degradation factors leads to a reduction in generation capacity. One of the relatively new solutions to mitigate the mismatch concerns between the PV modules and sub-modules is to extract the maximum power of each sub-module individually. The main objective of this paper is to present a comprehensive review of such PV grid-connected inverters topologies associated with sub-module connection and control. It will classify the PV grid-tied inverters in accordance with the level where the maximum power point tracking (MPPT) system is implemented. A special focus has been placed on sub-module microinverters (MI) in terms of circuit topologies, conversion efficiency, and controller design. This paper provides a comprehensive analysis of employing the distributed MPPT (DMPPT) approach to maximize the power generation of PV systems by mitigating the mismatch issues inside the PV module. The circuit topology, PV system configuration, and MPPT algorithms used for applying DMPPT solutions in PV SMs are discussed in detail in this study.

Chapter 18 - DCS in electrical controls and SCADA

Modelling and analysis of a power line communication system with QPSK modem for renewable smart grids

The atmospheric radio occultation (RO) technique was developed six decades ago for planetary missions and has since resulted in numerous scientific discoveries throughout the Solar System. The traditional experimental configuration utililizes spacecraft communication links with phase-stable radio signals transmitted from a spacecraft orbiting or flying past a planet and received at a ground station after propagating through the atmosphere. Alterations in the phase and amplitude are used to infer properties of that atmosphere. A reverse configuration with a ground-to-spacecraft one-way link has been used with the appropriately instrumented mission to Pluto to overcome severe signal-to-noise ratio limitations. A more recently investigated spacecraft-to-spacecraft occultation technique utilizes UHF communication links between Mars landers and orbiters to measure ionospheric properties.In 1995, the Earth science community demonstrated a variation of this technique that enabled remote sensing of Earth’s atmosphere and ionosphere. By tracking spacecraft-to-spacecraft crosslinks utilizing the global navigation satellite constellations as the transmitting terminals and specially instrumented satellites as the receiving terminals, high resolution vertical profiles are routinely retrieved with valuable utility in numerical weather prediction and atmospheric dynamics. Applying crosslinks more generally to planetary missions would allow large increases in spatial and temporal coverage of atmospheric structures and composition; however, this has been prohibitively costly until recent technological advances and breakthroughs.The advances of the required technologies for crosslink RO experiments currently enable realistic planning of their use in future planetary missions. These crosslinks could use orbiting small spacecraft for one or multiple links, and possibly probes, aerobots (e.g., balloons), and landers equipped for relay communications. These technologies and techniques include:1.Small software-defined radios2.Multi-frequency communication links3.Smaller ultra-stable oscillators4.Advancedsignal processing and holographic methods5.Interplanetary flight, orbit insertion, and formation-flyingThis paper presents the state of the art of these technologies and introduces lower cost mission concepts to Venus, the giant planets, and other planetary targets in the context of recent Decadal Surveys. These multi-spacecraft missions provide natural opportunities for international collaboration. Design requirements, recent simulations, radio-holographic analysis methods, and lessons from an opportunistic UHF crosslink demonstration at Mars will be discussed.

We discuss the sources and levels of background light that should be expected on space based laser communication (lasercom) crosslinks and uplinks, as well as on downlinks to ground stations. The analyses are valid for both Earth orbiting satellites and inter-planetary links. Fundamental equations are derived suitable for first order system engineering analyses of potential lasercom systems. These divide sources of background light into two general categories: extended sources which fill the field of view of a receiver’s optics, and point sources which cannot be resolved by the optics. Specific sources of background light are discussed, and expected power levels are estimated. For uplinks, reflected sunlight and blackbody radiation from the Earth dominates. For crosslinks, depending on specific link geometry, sources of background light may include the Sun in the field of view (FOV), reflected sunlight and blackbody radiation from planets and other bodies in the solar system, individual bright stars in the FOV, the amalgam of dim stars in the FOV, zodiacal light, and reflected sunlight off of the transmitting spacecraft. For downlinks, all of these potentially come into play, and the effects of the atmosphere, including turbulence, scattering, and absorption contribute as well. Methods for accounting for each of these are presented. Specific examples are presented to illustrate the relative contributions of each source for various link geometries.

Through the use of recent technological developments, it is now feasible to establish free-space optical (FSO) communication links over ultra-long distances. Recent research has shown that FSO systems could be deployed to establish high-rate data links to deep space. This study analyzes beam steering tolerances, beam divergence, and geometric loss for different distance ranges of interest for FSO communication links based on a mechanical gimbaled beam steering mechanism. The tolerance, divergence and geometric loss calculations are performed to evaluate the feasibility of establishing FSO links between the Earth and satellites, the Earth and aircraft, aircraft and satellites, the Earth and moon, the Earth and Mars, and the Earth and the edge of the solar system. The analysis and calculations performed take into consideration the availability of new technology such as low noise photon-counting detectors and fiber lasers and amplifiers. The beam steering tolerance and divergence calculations provide beneficial information for determining the extent to which future FSO systems could be deployed for both commercial, military and space exploration applications. Recommendations on the suitability of an FSO communication link for various applications are then made based on the beam steering tolerance and divergence calculations.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Wireless communication is an essential technology to unlock the full potential of unmanned aerial vehicles (UAVs) in numerous applications and has thus received unprecedented attention recently. Although technologies such as direct link, WiFi, and satellite communications are still useful in some remote scenarios where cellular services are unavailable, it is believed that exploiting the thriving 5G and beyond cellular networks to support UAV communications is the most promising and cost-effective approach, especially when the number of UAVs grows dramatically. On the one hand, to guarantee safe and efficient flight operations of multiple UAVs, it is of paramount importance to provide secure and ultra-reliable communication links between the UAVs and their ground pilots or control stations for conveying command and control signals, especially in beyond-visual-line-of-sight (BVLOS) scenarios. On the other hand, because of advances in communication equipment miniaturization as well as UAV manufacturing, mounting compact and lightweight base stations (BSs) or relays on UAVs becomes increasingly feasible. This has led to two promising research paradigms for UAV communications, namely, UAV-assisted cellular communications and cellular-connected UAVs, where UAVs are integrated into cellular networks as aerial communication platforms and aerial users, respectively. As such, integrating UAVs into cellular networks is believed to be a win-win technology for both UAV-related industries and cellular network operators, which not only creates plenty of new business opportunities but also benefits the communication performance of 3-D wireless networks. In addition, UAV related sensing and computing are also helpful for achieving efficient and reliable communication (e.g., in avoiding coverage holes) as well as smart UAV coordination, positioning, and trajectory design. However, 5G and beyond wireless networks with UAVs significantly differs from traditional communication systems, because of the high altitude and high maneuverability of UAVs, the unique UAV-ground channels, the diversified quality of service (QoS) requirements for downlink command and control (C&C) and uplink mission-related data transmission, the stringent constraints imposed by the size, weight, and power (SWAP) limitations of UAVs, as well as the new design degrees of freedom enabled by joint UAV mobility control and communication resource allocation.

In this paper a concept for a communication and tracking system for search and rescue operations especially of rescue dog associations in areas with poor mobile coverage is proposed.The concept includes tracking devices for all team members and dogs, a smartphone app for in-field communication as well as a web-based software for mission management.To ensure reliable communication even in difficult terrain, a combination of public 5G and private long range wide area network (LoRaWAN) is employed.With the later serving as fallback communication link, when no data transmission over 5G is possible.To ensure data transfer in the narrow LoRaWAN band, various techniques like message compression are considered.

Millimeter-wave hybrid OFDM-MDM radio over free space optical transceiver for 5G services in desert environment

The 5G communication systems will enable enhanced mobile broadband, ultra-reliable low-latency, and massive connectivity services. Broadband and low-latency services are indispensable to public safety (PS) communication during natural or man-made disasters. Recently, 3GPP-LTE has emerged as a promising candidate to enable broadband PS communications. In this article, first we present six major PS-LTE enabling services and the current status of PS-LTE in 3GPP releases. Then, we discuss the spectrum bands allocated for PS-LTE in major countries by ITU. Finally, we propose a disaster resilient three-layered architecture for PS-LTE (DR-PS LTE). This architecture consists of an SDN layer to provide centralized control, UAV cloudlet layer to facilitate edge computing or to enable the emergency communication link, and a radio access layer. The proposed architecture is flexible and combines the benefits of SDNs and edge computing to efficiently meet the delay requirements of various PS-LTE services. Numerical results verified that under the proposed DR-PSLTE architecture, delay is reduced by 20 percent as compared with the conventional centralized computing architecture.

Future lunar missions require robust 5G communication links, and their design depends partly on path loss characterization, link budget planning inputs, and path prediction loss models tailored to the Moon’s environmental conditions. This work develops a site-specific 5G large-scale path loss model for Shoemaker Rim F at 5.855 GHz using a high-resolution lunar digital elevation map and 3D ray tracing in Wireless Insite. Two link configurations were studied—dipole transmitter to dipole receiver (DD) and omni transmitter to dipole receiver (OD)—under five path loss cases: measured path loss, free space path loss (FSPL) with and without antenna patterns, and excess path loss with and without antenna patterns. The close-in (CI) and floating intercept (FI) model parameters are derived to develop a mathematical model for path loss prediction for the Shoemaker RIF’s terrain on the lunar south pole. The CI and FI for the DD configuration revealed a path loss exponent of 2.5378 and RMSE values of 45.15 dB and 43.898 dB, while the CI and FI for the OD configuration yielded a path loss exponent of 4.3280 and RMSE values of 6.301 dB and 66.739 dB, indicating strong sensitivity to the transmitter radiation pattern.

In order to support the mid-2020 and beyond, the development of high-speed, high-capacity wireless communication systems for 5G (5th Generation) networks has become an urgent and important issue in areas where optical fiber installation has not progressed due to geographical and economic reasons. Toward the 5G and beyond networks, HAPS (High Altitude Platform Station) which is located at an altitude of 20km can provide communication links to aircraft, drones, flying cars, ships, and expand the coverage to the sky and the sea. The HAPS makes it possible to provide low latency, high speed 5G communication services in these areas, and it is also possible to realize a communication system that can handle all use cases. This paper describes the development status of a 5G network backhaul system using HAPS in the millimeter wave band. This research and development is carried out from 2020 to 2023 by the Ministry of Internal Affairs and Communications "Research and Development for Expansion of Radio Resources".

5G communication technology has become well established in daily life, but its use in industrial control remains in its early stages of development. Due to its low latency and high reliability, 5G URLLC holds substantial potential for development in industrial control. Meanwhile, although SharkNet offers high transmission speed and reliability, its dependence on wired connections limits its coverage and flexibility.To address these limitations, this paper proposes a novel wireless communication link adaptation scheme that integrates 5G URLLC and SharkNet. We first conduct an in-depth analysis of the data packet formats and communication timing characteristics of both SharkNet and 5G protocols. Based on this analysis, we design a protocol conversion scheme and prototype a wireless link system. To validate the adaptability and performance of this scheme, we conducted a number of experiments to evaluate its reliability and latency. The experimental results indicate that compared with a transparent transmission approach, the proposed adaptation scheme significantly reduces communication latency and enhances reliability.

Recent events have shown that in the aftermath of an unexpected incident, communication infrastructures play an important role in supporting critical services. Airborne communication networks have been recently studied for the provision of wireless communication services and it is a promising candidate for rapidly deployable and resilient emergency networks. However, the choice of communication technologies from Aerial platforms is a challenging issue and depends on a variety of factors including platform payload capacity, coverage and capacity requirements, to name a few. In this paper, we investigate the performance of 4G LTE-WiFi multimode base stations deployed on airborne platforms which provides coverage for first responders during emergencies. We present an adapted simulation model for the analysis of hybrid aerial-terrestrial systems and study the impact of platform elevation and mobility on the cell coverage and channel capacity. Performance analysis with a platform deployment of a single Aerial Base Station (eNodeB) corroborates that airborne units with 4G communication capabilities are very promising candidates for robust communication links during emergency relief operations.