Locational Marginal Price Stability via Load Domain Calculation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The increasing penetration of renewable energy and electric vehicles in the power system makes the locational marginal price vulnerable to system congestion, necessitating a method to evaluate the impact of nodal loads and determine a parameter changing domain to ensure a constant locational marginal price for safe and economic operation.

Innovation Solution

A method is developed to calculate the parameter changing domain of loads using a locational marginal price clearing model, which involves establishing a clearing model, transforming it into a linear programming form, and applying first-order KKT conditions to derive the parameter changing domain, ensuring the locational marginal price remains constant under incremental loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If renewable energy penetration and electric vehicle adoption increase in the power system, then energy sustainability and electrification progress are improved, but system congestion increases and locational marginal price becomes vulnerable to nodal load changes

Engineering Contradiction:
Improverenewable energy penetrationVSAvoidlocational marginal price stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent performs preliminary calculation of the parameter changing domain before actual market operation. By pre-determining the range of nodal load changes that maintain constant locational marginal price, the system can predictively identify safe operating boundaries and take preventive actions before congestion occurs, thus maintaining price stability despite increasing renewable penetration

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent establishes a feedback mechanism where the calculated parameter changing domain is used to monitor and evaluate actual nodal load changes. When load changes remain within the calculated domain, the locational marginal price is guaranteed to remain constant. This feedback loop enables continuous verification and adjustment to maintain reliability while accommodating renewable energy variability

Inventive Principle:
Principle #23Feedback

2Productivity

If economic dispatch model is used for market clearing, then market efficiency is improved, but the complexity of evaluating nodal load impact on locational marginal price increases

Engineering Contradiction:
Improvemarket clearing efficiencyVSAvoidevaluation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts the critical evaluation function from the complex economic dispatch model by specifically calculating the parameter changing domain that guarantees constant locational marginal price. This extraction separates the price stability evaluation from the overall market clearing process, reducing evaluation complexity while maintaining market efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the complex evaluation problem into a parameter-based approach by defining the parameter changing domain in terms of nodal load variations. Instead of evaluating the entire economic dispatch model's sensitivity to load changes, the method identifies specific parameter ranges (load changes) that maintain price constancy, significantly simplifying the evaluation process

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the parameter changing domain of loads is calculated to guarantee constant locational marginal price, then price stability is improved, but the computational burden increases

Engineering Contradiction:
Improvelocational marginal price stabilityVSAvoidcalculation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs the parameter changing domain calculation as a preliminary step before actual market clearing operations. By pre-calculating the domain boundaries once, the system avoids repeated complex computations during real-time operation, thus maintaining price stability while minimizing computational time loss during critical market clearing phases

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a dynamic calculation approach where the parameter changing domain is calculated based on the current base state of the power system. As system conditions change (generation mix, network topology, demand patterns), the domain calculation is updated accordingly. This dynamic approach ensures price stability guarantees remain valid while avoiding unnecessary recalculations when system state remains within the same operational regime

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11616371B2Method for calculating parameter changing domain of loads under a case that guarantees constant locational marginal price in electricity market
Publication Date: 2023.03.28 STATE GRID FUJIAN ELECTRIC POWER RES INST

AI summary

The disclosure provides a method for calculating a parameter changing domain of loads under a case that guarantees a constant locational marginal price in an electricity market, which relates to the electricity market field of the power system. With the method in the disclosure, the clearing model on the locational marginal price in the general form is established, and the safe changing domain of the locational marginal price with respect to the loads may be derived and calculated based on the first-order KKT condition expansion of the clearing model on the locational marginal price in the general form. When the increment of the nodal loads is subordinate to the changing domain, the locational marginal price may remain unchanged. The parameter changing domain of loads in the power system may be used for the comprehensive evaluation of power market clearing results and assisting the operation of the power market.