Electromigration in metal lines has re-emerged as a significant concern in modern VLSI circuits. The higher levels of temperature and the large number of EM checking strategies, have led to a situation where trying to guarantee EM reliability often leads to conservative designs that may not meet the area or performance specs. Due to their mostly-unidirectional currents, the problem is most significant in power grids. Thus, this work is aimed at reducing the pessimism in EM prediction. There are two sources for the pessimism: the use of the series model for EM checking, and the pessimistic assumptions about chip workload. Therefore, we propose an EM checking framework that allows users to specify conditions-of-use type constraints to capture realistic chip workload, and which includes the use of a novel mesh model for EM prediction in the grid, instead of the traditional series model.

Power grid voltage integrity verification requires checking if all the voltage drops on the grid are less than a certain threshold that guarantees proper circuit operation. This thesis addresses the problem of correcting the grid when some voltage drops exceed this threshold by making minor modifications to the existing design. The method uses current constraints that capture the uncertainty about the underlying circuit behavior to find the maximum voltage drop on the grid, and then to estimate the voltage drop as a function of the metal widths on the grid. It formulates a nonlinear optimization problem and finds the required change in widths that reduces the maximum voltage drop on the grid below the threshold while keeping the total area cost at a minimum.

Power grid voltage integrity verification requires checking if all the voltage drops on the grid are less than a certain threshold that guarantees proper circuit operation. This thesis addresses the problem of correcting the grid when some voltage drops exceed this threshold by making minor modifications to the existing design. The method uses current constraints that capture the uncertainty about the underlying circuit behavior to find the maximum voltage drop on the grid, and then to estimate the voltage drop as a function of the metal widths on the grid. It formulates a nonlinear optimization problem and finds the required change in widths that reduces the maximum voltage drop on the grid below the threshold while keeping the total area cost at a minimum.

Power grids have a high content of metal, mainly copper and aluminium. When old cables reach their end-of-life, or in some way lose their intended purpose, they are usually left lying in their subsurface position. Material no longer used, but not yet discarded as waste, is in a state known as hibernation. Over time there is an accumulation of hibernating cables under ground that potentially could be recovered or “mined”. The aim of this study is to examine the total hibernating metal content of an urban, subsurface power grid, how it is distributed and also what reasons for disconnection are the most common. The focus of the study is the power grid of Linköping. Using a GIS based variant of material flow analysis the hibernating metal stock is examined both in terms of size and spatial distribution. The results of the study show a significant amount of hibernating copper and aluminium; in total 240 tons of metal were identified. By comparing the results with previous studies both similar and differing patterns appear. The main differences lie in the distribution of the stock within the city which is affected by the characteristics of the cities. When examining the reasons for disconnection continuous repair and maintenance work seems to be the most common reason for disconnection of cables. Further studies on how the characteristics of a city affects the formation of hibernating metal stocks in the infrastructure are suggested.

A resilient power grid system is important to ensure the delivery of power to consumers while minimizing the cost of new technologies. Due to the increase of electricity consumption and CO2 emission, renewable energies and energy storage system are a compelling alternative. We started to identify decisions that need to be made, and parameters associated to model a power grid system expansion plan. Then, we investigated a utility company demand for the next 15 years. Also, we identified their current resources, and used that as a starting point. Then, we formulated an optimization model for a power grid expansion with different types of renewable energies, such as solar and wind, to meet the demand and minimize the cost of installation; as well as, a battery storage system (Lithium-ion) that is considered to come up with an optimal solution of a resilient power grid. Moreover, uncertainties of renewables are considered in the model, and robust optimization formulation is used to model them. Existing coal facilities are considered as a part of the model as well, and this part is designed on the optimization model in a way that would help decrease the use of such facilities and still manage them to meet demand. Numerical experiments are performed on several scenarios, and compared to what the utility company has forecasted in terms of cost, and renewable energies integration.A resilient power grid system is important to ensure the delivery of power to consumers while minimizing the cost of new technologies. Due to the increase of electricity consumption and CO2 emission, renewable energies and energy storage system are a compelling alternative. We started to identify decisions that need to be made, and parameters associated to model a power grid system expansion plan. Then, we investigated a utility company demand for the next 15 years. Also, we identified their current resources, and used that as a starting point. Then, we formulated an optimization model for a power grid expansion with different types of renewable energies, such as solar and wind, to meet the demand and minimize the cost of installation; as well as, a battery storage system (Lithium-ion) that is considered to come up with an optimal solution of a resilient power grid. Moreover, uncertainties of renewables are considered in the model, and robust optimization formulation is used to model them. Existing coal facilities are considered as a part of the model as well, and this part is designed on the optimization model in a way that would help decrease the use of such facilities and still manage them to meet demand. Numerical experiments are performed on several scenarios, and compared to what the utility company has forecasted in terms of cost, and renewable energies integration.

Climate change and air pollution pose serious consequences including longer heat waves and sea level rise. California is taking several initiatives to address these problems, calling for an 80% reduction in greenhouse gas emissions by 2050 from 1990 levels. The transportation sector in California has relied heavily on fossil fuels, significantly contributing to the emissions of greenhouse gas emissions. As a result, one of the main technologies the state has been motivating to combat this is the implementation of battery electric vehicles. These vehicles have not started gaining popularity until recently and there are still several market barriers that slow down electric vehicle adoption, such as availability of charging ports. Several other aspects need to be considered, such as the effects on grid demand and supply, as California expects to see a large- scale implementation of electric vehicles. This paper aims to provide information on California's long-term transportation electrification goals and analyze how the state is progressing towards their stated goals, given current electric vehicle market trends, charging availability, and electric demand and supply capacity.

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. The case study design is performed on the campus distribution system of California Polytechnic State University, San Luis Obispo, with the design goal of implementing renewable energy sources to make the campus a net zero energy consumer.

To ensure the robustness of an integrated circuit design, its power distribution network (PDN) must be validated beforehand against any voltage drop on VDD nets. However, due to the increasing size of PDNs, it is becoming difficult to verify them in a reasonable amount of time. Lately, much work has been done to develop Model Order Reduction (MOR) techniques to reduce the size of power grids but their focus is more on simulation. In verification, we are concerned about the safety of nodes, including the ones which have been eliminated in the reduction process. This work proposes a novel approach to systematically reduce the power grid and accurately compute an upper bound on the voltage drops at power grid nodes which are retained. Furthermore, a criterion for the safety of nodes which are removed is established based on the safety of other nearby nodes and a user specified margin.

To ensure the robustness of an integrated circuit design, its power distribution network (PDN) must be validated beforehand against any voltage drop on VDD nets. However, due to the increasing size of PDNs, it is becoming difficult to verify them in a reasonable amount of time. Lately, much work has been done to develop Model Order Reduction (MOR) techniques to reduce the size of power grids but their focus is more on simulation. In verification, we are concerned about the safety of nodes, including the ones which have been eliminated in the reduction process. This work proposes a novel approach to systematically reduce the power grid and accurately compute an upper bound on the voltage drops at power grid nodes which are retained. Furthermore, a criterion for the safety of nodes which are removed is established based on the safety of other nearby nodes and a user specified margin.

This thesis focused on modeling and simulation of simultaneous switching noise in packages as well as integrated circuits and the focus was mainly on the latter. Efficient and accurate methods have been developed for modeling the coupling due to SSN in multi-layered planes arising in electronic packages, extraction of the power grid in integrated circuits and simulation of the power supply noise in large size networks arising in power distribution network. These methods include conformal mapping, finite difference time domain and cavity resonator methods, using which the electrical performance of the power distribution system in a high speed electronic product can be predicted. The model developed for field penetration captured the effect of the magnetic field penetrating through planes in multi-layered packages. Analytical model for the extraction of the interconnect parasitics for a regular on-chip power grid has been presented. Complex image technique has been applied for modeling the dispersive interconnect on lossy silicon substrate. The Debye rational approximation has been used to approximate the RLGC parameters in order to simulate the frequency dependent elements in the time domain. The simulation of the entire network of the full-chip power grid has been carried out using the modified FDTD expressions. Several aspects of characterizing the generic on-chip power distribution network have been presented. The crossover capacitance has been evaluated using analytical model derived from conformal mapping. An analytical model has been proposed to extract parameters of on-chip multi-conductor transmission lines, which guarantees the stability and is applicable to general distribution of multi-conductor transmission lines. The above modeling procedures have been incorporated into a computer program, which generates the power grid model from the layout of chip power distribution networks automatically. Research on 3-D on-chip power distribution networks has been presented. The complex image technique has been extended from microstrip-type interconnects to stripline-type interconnects. Macromodel images have been derived with closed form expressions to capture the loss mechanism of the multiple conductive substrates. The effect of 3-D integration on switching noise has been illustrated in the time domain using examples.