Power Router Research Articles

Erratum: “Novel Heat Sink Design Utilizing Ionic Wind for Efficient Passive Thermal Management of Grid-Scale Power Routers” [ASME J. Therm. Sci. Eng. Appl., 7(3), p. 031004

An index error in the numerical procedure calculating the ion density and the electric field was discovered. While the general concepts, the numerical method, and the main conclusions presented in the paper remain valid, the index error resulted in incorrect figures. The rectified plots and results are presented below.The calculations are run for different values of applied voltage ranging from 3500 V to 5000 V. The solution for the electric field and the free charge density is presented in Figs. 1 and 2, respectively, for an applied voltage of 5000 V.The body force applied on the fluid is the product of the electric field and the ion density. The magnitude of the body force in horizontal and vertical directions is shown in Figs. 3 and 4. The velocity profile at the entrance of the heat exchanger channel is shown in Fig. 5 for different applied voltages. The channel Reynolds number did not exceed 1150, which is well below the critical Reynolds number of 2300, therefore justifying the assumption of laminar flow (Fig. 6).The average heat flux across the wall of the channel at different voltages is presented in Table 1. Utilizing ionic wind heat transfer enhancement, a maximum heat flux of 502.9 W/m2 was found at an applied voltage of 5000 V.Finally, the heat flux obtained with ionic wind heat transfer enhancement is compared to the case with natural convection calculated according to Bar-Cohen and Rohsenow [2] as shown in Eqs. (1) and (2). Thereby, the constants C1 and C2 take value of 576 and 287, respectively. At a voltage of 5000 V, an increase in the heat flux of a factor four as compared to natural convection only was calculated (Fig. 7)(1)Nu¯S=[C1(RaSS/L)2+C2(RaSS/L)1/2]−1/2=h¯Sk(2)q″=h¯(Ts−T∞)A novel passive cooling enhancement method for grid-scale power routers was presented. A numerical scheme based on finite difference approximation was developed to solve the electrodynamics problem. It is shown that the velocity profile at the exit of the ionic wind generator is proportional to the applied corona voltage. Consequently, the heat flux increases with increasing applied voltages. The total heat rejected to the ambient can be increased by a factor four as compared to natural convection only at an applied voltage of 5000 V. Given the described geometry of the power routers, this corresponds to a total cooling power of up to 2860 W. The active power input required by the ionic wind generator is less than 5.6 W. It is therefore demonstrated that corona electrodes combined with bonded fin arrays could potentially replace more costly and complex cooling systems such as thermosiphons and heat pipes. In future work, effort will be directed at the experimental validation of the presented numerical model.

電力融通ネットワークに対する線形計画モデルを用いた効率の解析と感度分析

This paper focuses on a distributed solar energy network composed of multiple clusters, which correspond households equipped with PV units, rechargeable batteries, electrical appliances, and an electric power router. The routers manage the power transfer over the clusters. We obtain the optimal power transfer for the most efficient power utilization using a linear programing model. In the numerical experiments, we use real data of power generation and consumption sampled by monitoring in a local city in Japan. First, the power usage efficiensies are compared among the networks with various consumption distributions over the clusters and various battery capacities using the obtained optimal solutions. As the result, the wider distribution of the consumption amount and an appropriate capacity of battery gives the higher efficiency. Second, the sensitivity analysis on the linear programming model shows when, where and how the optimal solution is affected by the change of generation or consumption amount.

Design of Efficient Router with Low Power and Low Latency for Network on Chip

The NoC consists of processing element (PE), network interface (NI) and router. This paper proposes a hybrid scheme for Netwok of Chip (NoC), which aims at obtaining low latency and low power consumption by concerning wired and wireless links between routers. The main objective of this paper is to reduce the latency and power consumption of the network on chip architecture using wireless link between routers. In this paper, the power consumption is reduced by designing a low power router and latency is reduced by implementing a on-chip wireless communication as express links for transferring data from one subnet routers to another subnet routers. The average packet latency and normalized power consumption of proposed hybrid NoC router are analyzed for synthetic traffic loads as shuffle traffic, bitcomp traffic, transpose traffic and bitrev traffic. The proposed hybrid NoC router reduces the normalized power over the wired NoC by 12.18% in consumer traffic, 12.80% in AutoIndust traffic and 12.5% in MPEG2 traffic. The performance is also analyzed with real time traffic environments using Network simulator 2 tool.

Novel Heat Sink Design Utilizing Ionic Wind for Efficient Passive Thermal Management of Grid-Scale Power Routers

This paper presents a numerical model assessing the potential of ionic wind as a heat transfer enhancement method for the cooling of grid distribution assets. Distribution scale power routers (13–37 kV, 1–10 MW) have stringent requirements regarding lifetime and reliability, so that any cooling technique involving moving parts such as fans or pumps are not viable. A new heat sink design combining corona electrodes with bonded fin arrays is presented. The model of the suggested design is solved numerically. It is predicted that applying a voltage of 5 kV on the corona electrodes could increase the heat removed by a factor of five as compared to natural convection.

Experimental validation of a single phase Intelligent Power Router

Current power networks are facing numerous challenges in transmission and distribution in order to accommodate distributed generation from renewables. As a result, the current grid needs to evolve towards a system with more control and resiliency. The Intelligent Power Router device, located at strategic nodes, permits to add novel functionalities. This device allows to fully control the power flow by the means of Voltage Source Converters. In this article, the operation modes of the Intelligent Power Router are proposed and discussed. Moreover, this paper presents the design of a single phase Intelligent Power Router, simulations that prove its capability to control the power flow; and finally, an experimental validation of the device operation is also offered.

FPGA Based Low Power Router Design Using High Speed Transeceiver Logic IO Standard

Communication is the major aspect that plays an important role in success of any organization. Information in the same way is another aspect as to have communication data or information is must. So with the help of computer networks it is possible to build an environment of communication and information. Router is main component of computer networks is an intelligent device uses to transfer data packets between various computer networks. Router must consume low power to perform its work in an efficient manner. To achieve the same the work has been done to make a FPGA based low power design using different standards of HSTL.

Flexible Security-Constrained Optimal Power Flow

Power router technology is maturing to the point of becoming a cost-effective enabler of increased transmission asset utilization. Power routers can enable a desirable increase in control of power systems, especially as infrastructure ages and degrades. This paper presents a formal extension to the traditional security-constrained optimal power flow (SCOPF) algorithm, named flexible security-constrained optimal power flow (FSCOPF), which utilizes power router control in the post-contingency timeframe. The operational improvement is enabled by the fast-response capability of FACTS-based power routers to change setpoints in response to power system contingencies. The FSCOPF algorithm, developed in this paper, allows for power routers to be used as a real-time dispatchable resource. We show that further power system savings are achieved when compared to the traditional SCOPF.

The Three-Phase Power Router and Its Operation with Matrix Converter toward Smart-Grid Applications

A power router has been recently developed for both AC and DC applications that has the potential for smart-grid applications. This study focuses on three-phase power switching through the development of an experimental setup which consists of a three-phase direct AC/AC matrix converter with a power router attached to its output. Various experimental switching scenarios with the loads connected to different input sources were investigated. The crescent introduction of decentralized power generators throughout the power-grid obligates us to take measurements for a better distribution and management of the power. Power routers and matrix converters have great potential to succeed this goal with the help of power electronics devices. In this paper, a novel experimental three-phase power switching was achieved and the advantages of this operation are presented, such as on-demand and constant power supply at the desired loads.

Pulsed Power Network Based On Decentralized Intelligence For Reliable And Lowloss Electrical Power Distribution

Abstract Pulsed power network is proposed for reliable and low loss electrical power distribution among various type of power sources and consumers. The proposed scheme is a derivative of power packet network so far investigated that has affinity with dispersion type power sources and has manageability of energy coloring in the process of power distribution. In addition to these advantages, the proposed scheme has system reliability and low loss property because of its intelligent operation performed by individual nodes and direct relaying by power routers. In the proposed scheme, power transmission is decomposed into a series of electrical pulses placed at specified power slots in continuous time frames that are synchronized over the network. The power slots are pre-reserved based on information exchanges among neighboring nodes following inherent algorithm of the proposed scheme. Because of this power slots reservation based on decentralized intelligence, power pulses are directly transmitted from various power sources to consumers with the least power dissipation even though a partial failure occurs in the network. The network operations with the proposed scheme is simulated to confirm the algorithms for the power slots reservation and to evaluate the power network capacity.

Power Router for Meshed Systems Based on a Fractionally Rated Back-to-Back Converter

Increasing energy demand and growth of wind generation have significantly increased the stress on the electric grid. The low investment in transmission infrastructure necessitates adoption of methods for efficient use of existing resources. Power converter-based FACTS devices, capable of dynamic power-flow control, have been the preferred solution to maximize utilization of existing infrastructure, but implementation of traditional FACTS solutions at transmission level voltages is complex and cost prohibitive. This paper proposes a power router (PR) for dynamic power-flow control in a meshed network. The proposed PR is realized by augmenting a transformer with a fractionally rated back-to-back converter. The main advantages of the proposed converter are the fractional converter rating and reduced low-frequency transformer requirement compared to the traditional FACTS solutions. This paper outlines the proposed PR topology, control range, controller design and demonstrates the functionality through simulation and experimental results.

MoDe-X: Microarchitecture of a Layout-Aware Modular Decoupled Crossbar for On-Chip Interconnects

The number of cores in a single chip keeps increasing with process technology scaling, requiring a scalable interconnection network topology. Buffered wormhole-switched interconnect architectures are attractive for such multicore architectures. The 2D mesh on-chip interconnect provides a scalable, cost-efficient, flexible, and reliable next-generation interconnect topology in this context. In this paper, we provide a microarchitecture for a power and area efficient router for a 2D mesh interconnect. We propose an efficient crossbar implementation, called MoDe-X, that uses a reasonable power-performance tradeoff. The MoDe-X router uses a Modular-Decoupled Crossbar (MoDe-X) that incorporates dimensional decomposition and segmentation to achieve power and area savings. However, unlike most prior work that considers only logical representation of the crossbars, MoDe-X is a physically aware router accounting for the actual layout of router components to reflect practical design requirements. Our simulation results and power estimate show that the MoDe-X router architectures can reduce the overall router area by up to 40 percent and power consumption by up to 35 percent with very little performance impact that occurs only at higher loads. Further, by applying aggressive power gating techniques the net power reductions can be as much as 99 percent for some workloads with no additional performance impact.

AC Power Local Network with Multiple Power Routers

Controlling power flow and achieving appropriate matching between power sources and loads according to the quality of energy is expected to be one of the approaches to reduce wasted energy consumption. A power router, proposed recently, has the capability of realizing circuit switching in a power distribution network. This study focuses on the feasibility of an AC power routing network system composed of multiple power routers. To evaluate the feasibility, we experimentally confirm the circuit switching operation of the parallel and series configurations of the power routers, so that the network system can be designed by the combination of parallel and series configurations.

A Topology Optimization Method of Application-Specific Network-on-Chip

Future high-end System-on-chips (SoCs) will be consisted of hundreds of cores integrated on a single chip. On-chip communication becomes the major performance bottleneck of SoCs. Network-on-Chip (NoCs) have become as the most prominent solution to on-chip communication problems. Network topology which affects the total network conformance is basic of network related researches. The objective of topology synthesis is to minimize the power consumption and router resources while satisfying bandwidth constraints. In this paper, we present a two-level genetic-algorithm (GA) based technique to synthesize application-specific NoC topology. Comparing to an existing three-level GA, experiments show that our technique saves 1.8% energy while saving great runtimes of 97.79%. Our technique generates approximate optimal topology less than one minute.

Smart Power Router: A Flexible Agent-Based Converter Interface in Active Distribution Networks

Due to the large-scale implementation of distributed generation, the power delivery system is changing gradually from a “vertically” to a “horizontally” controlled and operated structure. This transition has prompted the emergence of the active distribution network (ADN) concept as an efficient and flexible distribution system to deal with various challenging issues. This paper addresses a multiagent system (MAS) as a suitable technology to manage autonomous control actions and perform the coordination in an ADN. In this agent-based ADN a smart power router is implemented, which can flexibly integrate network areas and optimally manage power flows. Operational and control functions of the power router has been investigated in a laboratory experiment. In this lab setup, a configuration of the power router is established in a combination of a three-inverter system and an agent. The experiments show that the ADN can operate in an efficient and flexible way with the support of the power router interface. The control function of the inverters and the operation of MAS are thoroughly verified.

Floorplan-aware application-specific network-on-chip topology synthesis using genetic algorithm technique

Communication plays a critical role in the design and performance of multi-core systems-on-chip (SoCs). Networks-on-chip (NoCs) have been proposed as a promising solution to complex on-chip communication problems. As regular NoC topologies are infeasible to satisfy the performance demand for application-specific NoC, customized topology synthesis is therefore desirable. However, NoC topology synthesis problem is an NP-hard problem. In this paper, we propose a suboptimal genetic-algorithm based technique to synthesize application-specific NoC topology with system-level floorplan awareness. The method minimizes the power consumption and router resources while satisfying latency and bandwidth performance constraints. We have evaluated the proposed technique by running a number of representative benchmark applications and the results indicate that our method generates approximate optimal topologies effectively and efficiently for all benchmarks under consideration.

Multi agent systems: An example of power system dynamic reconfiguration

The energy management in complex power electronic systems especially in case of limited power availability is challenging. In these systems generators, loads, energy storage devices and electrical power routers must be dynamically controlled and reco

A Service-Centric Multicast Architecture and Routing Protocol

In this paper, we present a new multicast architecture and the corresponding multicast routing protocol for providing efficient and flexible multicast services over the Internet. Traditional multicast protocols construct and update the multicast tree in a distributed manner, which may cause two problems: first, since each node has only local or partial information on the network topology and group membership, it is difficult to build an efficient multicast tree; second, due to lack of complete information, broadcast is often used for sending control packets and data packets, which consumes a great deal of network bandwidth. In the newly proposed multicast architecture, a few powerful routers, called m-routers, collect multicast-related information and process multicast requests based on the information collected. The m-routers handle most of multicast related tasks, while other routers in the network only need to perform minimum functions for routing. The m-routers are designed to be able to handle simultaneous many-to-many communications efficiently. The new multicast routing protocol, called the Service Centric Multicast Protocol (SCMP), builds a shared multicast tree rooted at the m-router for each group. The multicast tree is computed in the m-router by employing the Delay Constrained Dynamic Multicast (DCDM) algorithm which dynamically builds a delay constrained multicast tree and minimizes the tree cost as well. The physical construction of the multicast tree over the Internet is performed by a special type of self-routing packets in order to minimize the protocol overhead. Our simulation results on NS-2 demonstrate that the new SCMP protocol outperforms other existing protocols and is a promising alternative for providing efficient and flexible multicast services over the Internet.

Pump efficiency improvement of a C-band tunable fiber laser using optical circulator and tunable fiber gratings

We propose and demonstrate a tunable fiber laser based on an optical circulator (OC) and two tunable fiber Bragg gratings (TFBGs). The OC acts as a pump power router to improve the pumping efficiency, and a 4% increase in overall conversion efficiency has been observed. The combined tuning spectra range of two TFBGs could cover the entire C-band spectrum from 1530 to 1560 nm. Stable laser output power above 10 dBm is obtained using 1.9 m of erbium-doped fiber and TFBGs with 50% reflectivity. With power equalization by using variable optical attenuators, the power variation is less than 0.1 dB in the whole C band with narrow linewidth of 0.05 nm. A signal-to-noise ratio of 60 dB and a continuous tuning resolution of 0.5 nm have been achieved. The TFBG-based tunable fiber laser can be a promising light source for WDM transmission and fiber sensor applications.

Conserving network processor power consumption by exploiting traffic variability

Network processors (NPs) have emerged as successful platforms for providing both high performance and flexibility in building powerful routers. Typical NPs incorporate multiprocessing and multithreading to achieve maximum parallel processing capabilities. We observed that under low incoming traffic rates, processing elements (PEs) in an NP are idle for most of the time but still consume dynamic power. This paper develops a low-power technique to reduce the activities of PEs in accordance with the varying traffic volume. We propose to monitor the average number of idle threads in a time window, and gate off the clock signals to unnecessary PEs when a subset of PEs is enough to handle the network traffic. We solve the difficulties arising from clock gating the PEs, such as redirecting network packets, determining the thresholds of turning on/off PEs, and avoiding unnecessary packet loss. Our technique brings significant reduction in power consumption of NPs with no packet loss and little impact on overall throughput.

Intelligent power routers: a distributed coordination approach for electric energy processing networks

The Intelligent Power Router (IPR), a concept based on scalable coordination, is proposed to control the next generation power network. Our goal is to show that by distributing network intelligence and control functions using the IPR, we will be capable of achieving improved survivability, security, reliability, and reconfigurability. Each IPR has embedded intelligence into it allowing it to switch power lines, shed load, and receive/broadcast local state-variable information to and from other IPRs. The information exchange capability of the routers will provide coordination among themselves to reconfigure the network when subject to a natural or man-made disaster. In this paper, we report our progress on six different activities around the creation of the IPR: IPR architecture; Communication Protocols among IPR; distributed controls; risk assessment of a system operated with and without IPR; power system reconfiguration based on a controlled islanding scheme using IPR; and the definition of the power routing as an ancillary service, since the IPR may provide improved efficiency and security in the context of a realistic market structure, such as Standard Market Design with LMP pricing algorithm. Finally, we present our effort to link this new concept to an education plan that addresses the socio-technical nature of power systems and the education needs of the new workforce.