Electric Vehicle-Induced Grid Impact Analysis and Its Minimization

Electric vehicles are a major component of the clean energy transition. With significant technology improvement and government policies, EVs have increased to 10 million globally. A major bottleneck to accommodate the projected EVs is the development of an affordable and convenient charging infrastructure without needing long waiting times or long-distance travel for charging. As EV chargers draw power from the utility grid, adding the EV charging load impacts the utility grid significantly. This thesis investigates the impact of EV charging load on three vital grid-performance indicators (voltage profile, load demand curve, and harmonic profile) and develops solutions to minimize them. Firstly, the power electronic circuitry and control algorithms are studied to identify a grid-connected EV load’s power/energy requirements and harmonic profile. Moreover, considering the inter-dependency of voltage profile and power demand, these two parameters are investigated together. An IEEE 33-bus system is considered, and the actual load data of Qatar’s utility grid is used to define it. A novel two-step EV distribution algorithm has been developed, which helps estimate the 24-hour EV hosting capacity of the network without any intermediate line sections. Furthermore, the impact of the unavailability of DC fast chargers and level-2 chargers (located in parking lots) on EV hosting capacity is investigated to observe whether domestic chargers can address this shortfall. Renewable-based distributed generators (DG) are optimally placed in the grid using an optimization algorithm to improve the voltage profile and EV hosting capacity. The constraints to this optimization problem reflect the real-world challenges and discourage any transformer or line feeder upgrade. This strategy, known as the non-wire alternative approach, reflects the modular and active solution-based approach of extending the grid performance. The results are assessed and compared with the pre-DG results regarding voltage profile, EV hosting capacity improvement, and peak-shifting phenomenon. As both the EV charging current and DG injected current contain harmonics, the grid voltage contaminates and thereby deteriorates the power quality of the network. The impact of this deterioration on the grid must be quantified and compared with the actual distribution network. To analyze the overall impact, EVs and DGs are modeled as harmonic sources and added to the utility grid. This modifies the existing harmonic profile of the grid (due to original harmonic loads). Conventional methods of load-side filtering will be ineffective when the penetration levels of these components increase. To address this concern, a novel distributed filtering algorithm is developed, which analyzes the harmonic profile of the entire grid to determine the optimal location of active filters and their power rating. Post-filter placement, the distribution network becomes IEEE 519-2014 compliant.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

Texas A&M University

Year dc:date.issued

2024

Author dc:creator

• Syed Rahman,

Advisor dc:contributor.advisor

• Khan, Irfan A.

Committee members dc:contributor.committeemember

• Capar, Ismail
• Bhattacharyya, S

• Engineering, Electronics and Electrical

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/1969.1/1589322

OAI record oai:identifier

https://oaktrust.library.tamu.edu/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Aoaktrust.library.tamu.edu%3A1969.1%2F1589322