Power Plant Transformer Thermal Design for Variable Renewable Loads

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Solution Overview

Problem

Conventional transformers designed for steady loads are over-dimensioned and expensive when used in renewable energy plants due to variable loads, weather-dependent power generation, and lower capacity factors, leading to inefficient sizing and higher costs.

Innovation Solution

A method to optimize transformer design by defining critical temperatures based on material parameters and expected lifetime, using a processor-controlled manufacturing machine to adjust geometrical and electrical design parameters, and selecting suitable materials to achieve a compact and cost-effective transformer design suitable for renewable energy applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional transformers are designed with nameplate rating for maximum apparent power at maximum ambient temperature including emergency loading capacity, then the transformer can handle emergency loads and maintain high reliability, but the transformer becomes over-dimensioned, bulkier, and more expensive for renewable energy applications

Engineering Contradiction:
Improveemergency loading capacityVSAvoidtransformer size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent applies dynamic thermal modeling to transform the static nameplate rating approach into a dynamic evaluation system. The transformer's thermal state is continuously assessed based on actual loading patterns and ambient conditions, allowing the system to adapt its effective capacity in real-time rather than being constrained by fixed conservative ratings

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the evaluation parameters from static nameplate ratings to dynamic thermal state parameters. By monitoring actual operating conditions (loading patterns, ambient temperature, thermal inertia), the system adjusts the effective capacity assessment, allowing smaller transformers to meet reliability requirements without emergency loading capability

Inventive Principle:
Principle #35Parameter changes

2Temperature

If conventional transformers are designed with nameplate rating for maximum apparent power at maximum ambient temperature, then the transformer ensures adequate cooling performance, but the transformer is loaded considerably less than its loading capacity and becomes over-dimensioned

Engineering Contradiction:
Improvecooling performanceVSAvoidloading capacity utilization
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent implements a feedback mechanism through continuous thermal monitoring and evaluation. The dynamic thermal model uses actual operating data (loading patterns, ambient conditions, temperature measurements) to assess the transformer's true thermal state, providing feedback that reveals the mismatch between conservative nameplate ratings and actual thermal capacity utilization

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary thermal evaluation through dynamic modeling before making design decisions. By simulating and evaluating the transformer's thermal behavior under expected renewable energy loading patterns, the system determines the optimal size without over-dimensioning, ensuring adequate cooling performance is achieved through accurate prediction rather than excessive capacity

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If conventional transformers are designed for steady load conditions, then the transformer ensures stable operation, but the transformer does not account for variable renewable energy loads and weather-dependent conditions

Engineering Contradiction:
Improvesteady operationVSAvoidvariable load handling
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from static steady-state design to dynamic time-dependent thermal modeling. The system evaluates transformer performance under variable loading conditions by continuously updating the thermal state based on actual renewable energy generation patterns and ambient temperature variations, enabling stable operation assessment under adaptive conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters from constant steady-state values to time-varying parameters that reflect renewable energy characteristics. The dynamic model incorporates variable loading patterns, ambient temperature fluctuations, and thermal inertia effects, allowing the transformer design to adapt to weather-dependent conditions while maintaining stable operation through accurate thermal management

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The optimized transformer design ensures that critical temperature limits are met, reducing size and cost while maintaining performance, allowing for efficient operation in renewable energy plants with variable loads and ambient conditions.

Implementation Method 1

at least two critical temperatures in the operation of the transformer are defined. For at least two critical temperatures, a limit is defined. The limit may be defined by material parameters of the transformer and an expected life time

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4402601B1A method for obtaining an improved transformer design for a power plant
Publication Date: 2025.01.01 HITACHI ENERGY LTD
  • EP4402601B1 patent drawingFigure 1
  • EP4402601B1 patent drawingFigure 2
  • EP4402601B1 patent drawing

AI summary

A method for obtaining an improved transformer design for a power plant, comprises the steps of defining one or more critical temperatures (θhwnormal, θhwcontingency, θh, θo) in the operation of the transformer, determining a limit (θhw,max normal, θhw,max contingency, θh,max, θo,max) for at least one of the critical temperatures and obtaining an adjusted design of the transformer by using a data set of transformer loading, the data set comprising the amount of time (H) at a specific load level (κ) for a specific ambient temperature (θa). The method further comprises the step of producing a transformer having the adjusted values of the design parameters (Δθhr, Δθor, R, x, y) and/or using a transformer having the adjusted values of the design parameters (Δθhr, Δθor, R, x, y) in the power plant.