Unbounded system model allows robust communication infrastructure for power quality measurement and control

The deployment of renewable energy sources (RES) results in a degradation of power quality, necessitating the use of power conditioners such as active filters to alleviate these difficulties, while passive filters are inadequate of entirely mitigating power quality concerns in the presence of nonlinear loads. Numerous research have been undertaken to combine RES with active power filters in order to maximize the benefits of both RES and power conditioners in order to offer high-quality energy to customers. This chapter addresses the operation of RES in combination with active power filters. It also includes an interesting section on dual unified power quality conditioner (UPQC) operation and control, which helps clarify the active filter technologies that are viable for inclusion in the DG framework. The suggested UPQC is composed of an open-end winding transformers and series connected voltage source converters (VSCs). The proposed UPQC utilizes two photovoltaic arrays, with each array feeding a different dc-link of a two three-phase VSC. The feasibility of the suggested UPQC has been proven by simulated tests using Simulink®/MATLAB®.

For Smart Grid and Power Quality measurements, a communication system is required to sent tariff information and measure Voltage, Current and Power as well as reading a smart electricity meter. James Cook University is carrying out research on using Power Line Communications (PLC) signals on Single Wire Earth Return (SWER) lines for Smart Grid applications and Power Quality assurance. For SWER lines, the characteristic impedance of the line changes with frequency and the radiation losses sharply increase with frequency. This paper describes an accurate SWER line model, which incorporates these frequency dependencies to demonstrate the severe signal channel degradation that can occur due to line branches and coupling networks. This model is applicable to any power line. The model is verified with measurements from two sites. Data rates at 22.8 kbps with more than 14 dB excess CNR were obtained on a 14 km SWER line.

Command and control in real time of renewable energy are a fast-growing trend. The development of communication platform uses energy management software (Power studio technology) as a basis design for an overall system. The proposed prototype constructs Power Quality Analyzer. The main central control system will acquire data from the remote renewable energy system. All necessary monitor data include Voltage events and variations, Flicker, Harmonics, Unbalance and other control parameters will be stored in a control unit. Monitoring data is monitored as real-time data across Wireless Communication Systems using router in bridge mode to connect multiple devices wirelessly at the Power Quality Analyzer. This paper presents the metric application of Power Quality command and control systems for smart renewable energy power of useful Information. The authors approve that the metric application, Payload bitrate/forwarding time vs average message size, offers a remarkable flexibility results and gives a quick and easy idea of the possible Bitrate/Time in the wireless bridge network performance.

With more stringent power quality requirements imposed by electric utilities on electrical furnace operators, the accurate measurement of electrical parameters becomes more important. The overall performance of a power quality measurement system is a function of the accuracy of all of its transducers. This paper, through the use of measured electrical arc furnace data, investigates the sensitivity of power quality calculations to the dynamics of instrument transformers and sampling devices. Improved accuracy in measurements with real-time digital compensating filters is demonstrated using the furnace data.

Future PCS (personal communication system) cellular networks will mainly be driven by high link quality, high bandwidth utilization, low power consumption and efficient network management. Power control is one of the several major techniques which could help to achieve these goals. By exploiting power control techniques, co-channel interference could be reduced and as many links as possible could be obtained with satisfactory link quality. SIR-based (signal-to-interference ratio-based) power control was proposed as a technique for managing co-channel interference in cellular radio systems. Furthermore, new distributed autonomous feedback power control methods were introduced to achieve excellent performance without the difficult centralized control used in SIR-based methods. Unfortunately, the implementation of those power control algorithms is still challenging owing to the precision of SIR. The main aim of this paper is to investigate an uplink power control algorithm which depends indirectly on the signal-to-noise ratio in the TDMA (time division multiple access) cellular system. Simulation of the prototype hardware implementation of the receiver baseband signal processing based on the PACS (personal access communications system) specification is used as the main approach to explore the performance evaluation of this power control technique. According to simulation results, suitable values of those parameters used in this power control algorithm are derived, and the minimum frequency reuse factor under different propagation environments is also obtained for PACS under power control. © 1998 John Wiley & Sons, Ltd.

AAOISE, the Antarctic Astronomical Observations Intelligent Support Equipment, is an autonomous control equipment serving for energy support and environment thermal preservation, which is used for astronomical science observations in the Antarctic “Dome A”. It was deployed to “Dome A” and had an unattended run until now. The AAOISE stressed on the ways to adapt to adverse circumstances of “Dome A” and to have as little influence on the environment as possible. Its shape and structure are fully qualified for transportation and thermal insulation demands. The power generation and control systems are designed to provide continuous power and heat. Its communication system can support high-reliability data transmission and communications. It offers a possibility for developing “Dome A” scientific activities and remote monitoring of the running situation of the science instruments. This paper presents a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for AAOISE.

New radio technology suit very well to implement mobile positioning systems, because the future signals are wideband and software radio (SDR) defined platforms are used for implementation. If the used communication system is not sufficient for required positioning purposes, the SDR principle allows that the same platform is used or divided by a positioning system. These positioning systems function anywhere where the underlying communication systems have a sufficient coverage for positioning. Alternatively, a sufficient coverage can be guaranteed locally by establishing a positioning network. These local mobile positioning systems serve as a backup to or as a more robust alternative to global navigation satellite systems that are known to be rather vulnerable to interference. In this paper some design aspects of interference immune local mobile positioning systems are considered. The considered topics include a short introduction to the Finnish Software Defined Radio Programme, which covers both communications and positioning systems in the same platform. Topics considered herein include also positioning network design, delay estimation in frequency hopping systems with few samples and interference mitigation techniques both for single antenna and adaptive antenna receivers.

Building large resilient and computer systems can be challenging, especially when temporal predictability is also required. Large resilient systems are typically composed of different networking technologies, for example, using different wired and wireless communication technologies. Building such systems with safety-relevant services demands appropriate system interfaces and algorithmic concepts. In this talk we present some design patterns that are useful to build such large resilient and predictable systems. Often, the underlying communication medium does not provide the reliability and real-time properties that are needed for a concrete application. In such a case the presented design patterns can be implemented as a communication layer on top of the underlying communication system. We discuss design patterns for interaction autonomy, system communication and reliability.

Achieving NASA's lunar and Mars exploration objectives will require significant advances in space-qualified communications systems. The communications capabilities required by lunar missions and beyond cannot be supported through simple, point-to-point radio communications. While such radio links will may provide basic elements of the system, the number of communications sources, sensors, radios, etc. will necessitate the formation of networks. These networks will require the ability to form automatically, adapt to changing topologies, recover from faults, compensate for interference or other external factors inhibiting communications, and additional capabilities as mission needs evolve over the life of their deployment. The communications systems supporting these missions will require significant advances in the architecture and design over current systems. This paper presents work in progress to meet the needs of the next generation space-based communications and networking. I. Introduction roviding the communication capabilities required to support NASA’s planned space exploration missions to the moon, Mars and beyond will require significant advances over current systems. Long-term deployment, changing mission requirements and high data rates impose significant challenges. Providing these advanced capabilities must be achieved while meeting reliability requirements in a hostile space environment and balanced with the stringent size weight and power (SWaP) constraints of the spacecraft and launch capabilities. Through a combination of internal research and development (R&D) and a collaborative project with NASA, the challenges of advanced space-based communications systems are being addressed. How this class of communications systems will be applied to the near-term communications needs and support an evolution to support a wider range of capabilities over the life of the mission will be discussed. Looking beyond basic system upgrade and reconfiguration capabilities, more advanced capabilities such as autonomous ad hoc networks and lightweight routing protocols will be presented. How these technologies will contribute to the formation of adaptable, extensible, and highly reliable communications networks will be discussed. The paper will close with a discussion of how the capabilities will evolve in concert with the future objectives of space exploration missions. A. Communication System Objectives

This paper discusses distributed resource allocation and related stability issues in a communication system under uncertainty. Some recent approaches for decentralized resource allocation in a communication system are summarized. A characterization for the optimum resource control and pricing in a distributed wireless network with transmit power control is presented. Power control is modeled here as a game between the users, with given strategy spaces. Then, the learnability of the optimal strategies in a distributed communication network with pricing is addressed. Restricting the strategy spaces of the users, the resource allocation game between the users is learnable in the sense that the users can have almost optimal strategies for using the resources.

Most of the power control (PC) algorithms assumed that the link gains are fixed, and the power control command can take any value in the real field. These two assumptions are unrealistic in actual communication systems, since link gains are time varying and power control commands must be sent over capacity limited channels. In this paper, we propose a binary feedback power control algorithm (BFPC) for time-varying link gain environments. This algorithm can possibly be implemented as a 1-bit increase/decrease power control command, and we construct a connection between the link gains and the step-size of the proposed algorithm. It is shown that the proposed algorithm drives the CIR to an interval in time-varying link gain environments. Simulation results show that the proposed algorithm is more robust against link gains changes as compared to Foschini and Miljanic's distributed algorithm (FMA) and proportional power control algorithm (PropPC), and the proposed algorithm can be adopted in practical mobile communication systems.

In this article we present a survey of the power control techniques for modern wireless DS-CDMA communication systems. Power control is the single most important system requirement for DS-CDMA systems. Well-defined power control is essential for proper functioning of the DS-CDMA system. In the absence of power control the effect of near⁄far phenomena is dominant, and the capacity of the DS-CDMA mobile system is very low, even lower than that of mobile systems based on FDMA. However, when the power control in DS-CDMA systems exists, it allows users to share resources of the system equally between themselves. Also, with a proper power control it is possible to lower total transmitting power of the mobiles and prolong the battery life.

SUMMARYIn code division multiple access (CDMA) communication systems, the communication channel is usually corrupted with time‐varying interferences, which include channel fading, multiple access interference, round‐trip delay, and noise. Power control is an important issue for CDMA systems to achieve higher communication link quality and better system capacity under time‐varying interferences. In the previous studies, most of power control algorithms only considered the user's target signal‐to‐interference‐and‐noise‐ratio (SINR) to maintain quality of service. In this study, a multi‐objective optimization method is proposed for power control design in CDMA systems. With a shadow system and an h ∞ filter to compensate for the round‐trip delay, the proposed power control scheme can simply adjust transmission power to achieve the best compromise between several objectives, such as minimization of SINR deviation, minimization of power consumption, and minimization of the system outage. Several simulation results are given to confirm the performance of the proposed power control scheme. Copyright © 2013 John Wiley & Sons, Ltd.

Power control technology is necessary in Visible Light Communication (VLC) systems because of the multipath distortion and shadowing. When a power control algorithm is applied to the system, feedback error is inevitable. In this paper, we analyze the closed-loop power control algorithm and the influence of the power control error (PCE) in VLC systems. To analyze the effect of the PCE in VLC systems, the proposed system is studied with different modulation schemes and coding rates in terms of BER.

In wireless communication systems with multiple users, the near-far effect and the cochannel interferences decrease the spectral efficiency and system performance. An efficient known method to combat these destructive effects is to properly adjust the transmit powers. A practical and efficient way for power control (PC) in cellular communication systems is the autonomous distributed PC (DPC). In this method, the transmit power of each link is independently modified based on the received signal-to-interference-plus-noise ratio (SINR) reported from the other side of that link. It is known that in a perfect scenario where the reported SINRs are exact, this algorithm converges to the optimum transmit powers. However, in the case of erroneous SINR reports, the transmit powers deviate from their optimum values. This paper addresses the destructive effect of inaccurate SINR reports on the performance of a DPC algorithm. Then, independent variable step-sizes that update the transmit powers are proposed, and convergence of the proposed DPC algorithm to the optimum solution of the original problem is analytically shown. Additionally, a protocol to adaptively tune the step-sizes in our algorithm, which improves the performance of PC in the presence of inaccurate SINR reports, is proposed. Computer simulations are used to study the performance of the proposed method in terms of both the speed of converges and the steady-state accuracy of link qualities.