Brock J. LaMeres

A customer-interactive electric water heater demand-side management strategy using fuzzy logic

This paper describes a fuzzy logic-based demand-side management (DSM) strategy to shift the peaks of the average residential electric water heater power demand profile from periods of high demand for electricity to off-peak hours. The DSM strategy is achieved by dividing the distribution area water heaters into several blocks and controlling each by a different fuzzy controller. Simulation results are presented to show the effectiveness of the proposed DSM strategy to shift the average electric water heater peak demand to off-peak periods and to level utility distribution demand profile.

A multiple-block fuzzy logic-based electric water heater demand-side management strategy for leveling distribution feeder demand profile

Abstract This paper describes a multiple-block fuzzy logic-based demand-side management (DSM) strategy to shift the peaks of the residential electric water-heater power demand component of a distribution area from periods of high demand for electricity to off-peak hours. This is achieved by dividing the distribution area into several blocks and, controlling each block by a different fuzzy controller. Simulation results are presented to show the effectiveness of the proposed DSM strategy to shift the electric water-heater peak demand to off-peak periods and to level the utility distribution demand profile.

Encoding-Based Minimization of Inductive Cross-Talk for Off-Chip Data Transmission

Inductive cross-talk within IC packaging is becoming a significant bottleneck in high-speed inter-chip communication. The parasitic inductance within IC packaging causes bounce on the power supply pins in addition to glitches and rise-time degradation on the signal pins. Until recently, the parasitic inductance problem was addressed by aggressive package design. We present a technique to encode the off-chip data transmission to limit bounce on the supplies and reduce inductive signal coupling due to transitions on neighboring signal lines. Both these performance limiting factors are modeled in a common mathematical framework. Our experimental results show that the proposed encoding based techniques result in reduced supply bounce and signal degradation due to inductive cross-talk, closely matching the theoretical predictions. We demonstrate that the overall bandwidth of a bus actually increases by 85% using our technique, even after accounting for the encoding overhead. The asymptotic bus size overhead is between 30% and 50%, depending on how stringent the user-specified inductive cross-talk parameters are.

Fuzzy logic based voltage controller for a synchronous generator

Fuzzy logic controllers are rapidly becoming a viable alternative for classical controllers. The reason for this is that a fuzzy controller can imitate human control processes closely. Fuzzy logic technology enables the use of engineering experience and experimental results in designing an embedded system. In many applications, this circumvents the use of rigorous mathematical modeling to derive a control solution. Another advantage of fuzzy logic control is that it allows for a model-free estimation of the system. In other words, the designer does not need to state how the outputs depend mathematically upon the inputs. A fuzzy controller can be developed by encoding the structured knowledge of the system, which will allow faster control algorithms to be developed in less time and at less cost. With the advance of microprocessors and digital signal processors (DSPs), fuzzy logic control techniques are becoming more attractive for real-time control problems. It is expected that it will be implemented in many power system control applications in the near future. The paper describes a fuzzy logic based closed loop control system which controls the armature voltage of a generator by varying its field current in real-time.

Controlling the average residential electric water heater power demand using fuzzy logic

Abstract This paper describes a fuzzy logic-based control strategy for shifting the average power demand of residential electric water heaters. The proposed control strategy can shift the average power demand of residential electric water heaters from periods of high demand for electricity to off-peak periods. A minimum temperature for hot water, defined as customer comfort level, is used as a control variable. Water temperature is not allowed to fall below the minimum temperature set by the customer. Simulation results show that the proposed strategy can shift the average power demand of residential water heaters to improve the load factor of residential load profile.

Novel 3-D Coaxial Interconnect System for Use in System-in-Package Applications

This paper presents the design and demonstration of a novel die-to-die interconnect system for deployment in system-in-package (SiP) applications with adjacent or stacked-die configurations. The interconnect system consists of miniature coaxial cables that are mounted to a standard Silicon substrate using an etched trench along the perimeter of the die. The trench serves as a self-alignment feature for both the signal and ground contacts in addition to providing mechanical strain relief for the coaxial cable. The system is designed to interface on-chip coplanar transmission lines to off-chip coaxial transmission lines to produce a fully impedance matched system. This approach promises to dramatically improve the electrical performance of high-speed, die-to-die signals by eliminating impedance discontinuities, providing a shielded signal path, and providing a low-impedance return path for the switching signal. The new interconnect system is designed to be selectively added to a standard wire bond pad configuration using an incremental etching process. This paper describes the design process for the new approach including the fabrication sequence to create the transition trenches. Finite-element analysis is performed to evaluate the electrical performance of the proposed system.

An approach to evaluate the general performance of stand-alone wind/photovoltaic generating systems

Summary form only given as follows. This paper reports the development of a computer approach for evaluating the general performance of stand-alone wind/photovoltaic generating system. Simple models for different system components are developed, integrated and used to predict the behavior of generating systems based on available wind/solar and load data. The model is useful for evaluating the performance of stand-alone generating system and gaining a better insight in the component sizes needed before they are built. Simulation results are presented for performance evaluation of a stand-alone generating system that has been previously designed to supply the average power demand of a typical residential house. An electric water heater model is used as a dump load, and the excess available wind/solar-generated power is used to heat the water. The heated water is used as the inlet water to the main house water heater, which is assumed to be nonelectric. It is shown that this strategy can be effective in reducing the amount of fuel used by the main residential water heater.

Ionizing Radiation Detector for Environmental Awareness in FPGA-Based Flight Computers

Ionizing radiation has a detrimental effect on digital electronics which need to operate in extraterrestrial environments. Modern reconfigurable digital fabrics are enabling new architectures for flight computers, which can exploit environmental awareness to increase their fault tolerance. In this paper, we present the design, modeling, and characterization of a radiation sensor which can be coupled with a reprogrammable hardware fabric to provide spatial information about radiation events that can cause logical faults. The sensor uses a wide area PN junction as its fundamental sensing element. As radiation passes through the sensor, electron hole pairs are created. The internal electric field of the PN junction sweeps the charge carriers in opposite directions which are ultimately sensed by orthogonally placed electrodes on the top and bottom of the sensor. This XY grid provides the spatial location of an ionizing radiation strike, which can be fed to the coupled computer fabric for environmental awareness. A reverse bias voltage is applied to the sensor in order to fully deplete the substrate for maximum charge carrier generation. The sensor is designed to detect the spatial location of radiation strikes of energy levels, which can cause faults in commercial field programmable gate arrays substrates.

FPGA implementation of a Bartlett direction of arrival algorithm for a 5.8ghz circular antenna array

This paper presents the design and prototyping of a Bartlett direction of arrival algorithm for an adaptive array antenna system using a Xilinx Virtex-5 FX70 FPGA. The algorithm was prototyped in both full custom VHDL hardware and in a Xilinx MicroBlaze soft processor to analyze the performance tradeoffs between hardware and software implementations. The design was tested using an 8-element circular antenna testbed. The implementation and analysis presented in this work will aid system designers to understand the tradeoffs between implementing algorithms in custom hardware versus in an embedded system and when a hybrid approach is more advantageous. 1 2

Spatial avoidance of hardware faults using FPGA partial reconfiguration of tile-based soft processors

This paper presents the design of a many-core computer architecture with fault detection and recovery using partial reconfiguration of an FPGA. The FPGA fabric is partitioned into tiles which contain homogenous soft processors. At any given time, three processors are configured in triple modulo redundancy to detect faults. Spare processors are brought online to replace faulted tiles in real time. A recovery procedure involving partial reconfiguration is used to repair faulted tiles. This type of approach has the advantage of recovering from faults in both the circuit fabric and the configuration RAM of an FPGA in addition to spatially avoiding permanently damaged regions of the chip. 1 2