EV Depot Charging Location Selection for Voltage-Stable Scheduling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing EV depot energy management systems face challenges in maintaining voltage stability due to increased use of renewable energy resources and electric vehicle charging, leading to potential grid code violations and penalties.

Innovation Solution

A method for selecting a charging location for flexible loads within an EV depot's distribution network using load flow analysis and scheduling to minimize voltage violations, considering the capacity of charging stations and the need for fast charging, and dynamically adjusting the charging schedule to avoid under-voltage issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If renewable energy resources are utilized to maximum power generation, then unit cost is reduced, but voltage violations such as over-voltage occur in the distribution network

Engineering Contradiction:
Improveunit cost of energyVSAvoidvoltage stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system performs load flow analysis before scheduling EV charging to predict voltage violations in advance. By analyzing the distribution network state beforehand, the system can prevent over-voltage conditions by avoiding charging schedules that would cause grid code violations, thus resolving the contradiction between maximizing renewable energy utilization and maintaining voltage stability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the distribution network state and adjusts EV charging schedules based on real-time voltage conditions. This feedback mechanism allows the system to respond to changing network conditions, preventing voltage violations while maximizing renewable energy utilization by dynamically optimizing charging schedules

Inventive Principle:
Principle #23Feedback

2Productivity

If EV load is increased to meet charging demand, then charging capacity is improved, but voltage violations such as under-voltage occur in the distribution network

Engineering Contradiction:
Improvecharging capacityVSAvoidvoltage stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs load flow analysis to evaluate the impact of EV charging on distribution network voltage before committing to charging schedules. By predicting under-voltage conditions in advance, the system can adjust charging schedules to maintain voltage stability while meeting EV charging demands, thus resolving the contradiction between improving charging capacity and maintaining voltage stability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts EV charging schedules based on real-time distribution network conditions. By making charging schedules flexible rather than fixed, the system can respond to voltage changes and maintain stability while maximizing charging capacity utilization, resolving the contradiction between productivity and reliability

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If first-in-first-serve approach is used for EV charging scheduling, then operational simplicity is maintained, but grid code violations occur due to voltage instability

Engineering Contradiction:
Improvescheduling simplicityVSAvoidgrid code compliance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system automatically performs load flow analysis and generates optimized charging schedules without manual intervention. This self-service approach maintains operational simplicity by eliminating the need for manual scheduling while simultaneously ensuring grid code compliance through automated voltage stability checks, thus resolving the contradiction between ease of operation and reliability

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4283812A1Charging location selection of an incoming electric vehicle for large ev depot infrastructure
Publication Date: 2023.11.29 HITACHI ENERGY USA INC
  • EP4283812A1 patent drawingFigure 1
  • EP4283812A1 patent drawingFigure 2
  • EP4283812A1 patent drawingFigure 3

AI summary

As the use of renewable energy resources increases within charging infrastructures, the risk that charging an additional load within the charging infrastructure will create a violation of the applicable grid code also increases. In an embodiment, a charging location is selected for an incoming load based on a load flow analysis, to thereby mitigate the risk of a violation. This selection process may also account for the charging schedule of the load and the capacity of available charging stations (e.g., fast charging vs. slow charging).