KR-20260063475-A - Method for calculating design margin for power devices and system for calculating design margin for power devices

KR20260063475AKR 20260063475 AKR20260063475 AKR 20260063475AKR-20260063475-A

Abstract

A method for calculating a design margin of power equipment and a system for calculating a design margin of power equipment are disclosed. The method for calculating a design margin of power equipment according to the present invention comprises the steps of: preparing a database storing design values and test values of the power equipment; performing a statistical analysis based on the stored design values and test values to calculate a statistical moment that considers uncertainties including design errors, manufacturing deviations, and test conditions; and calculating a design margin based on the calculated statistical moment that minimizes the difference between customer specifications and design values and minimizes the sum of failure costs and product production costs.

Inventors

강병수
김덕건

Assignees

에이치디현대일렉트릭 주식회사

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (14)

In the method for calculating the design margin of power equipment, A step of preparing a database storing design values and test values of the above-mentioned power device; A step of performing a statistical analysis based on the stored design values and test values to calculate a statistical moment that considers uncertainties including design error, manufacturing deviation, and test conditions; and, A method for calculating a design margin for power equipment, comprising the step of calculating a design margin based on the above-calculated statistical moment to minimize the difference between customer specifications and design values and to minimize the sum of failure costs and product production costs.
In paragraph 1, The step of calculating the above statistical moment is, A method for calculating a design margin of power equipment characterized by calculating the average value, which is the first moment of the design value and the variance, which is the second moment of the test value, and quantitatively analyzing the variability of the performance distribution due to manufacturing deviation.
In paragraph 1, The step of calculating the above statistical moment is, A method for calculating design margins for power equipment, characterized by analyzing the asymmetry and peaking of a performance distribution, including skewness as the third moment and kurtosis as the fourth moment, by considering a random variable that follows a non-normal distribution.
In paragraph 1, The step of calculating the above statistical moment is, A method for calculating the design margin of a power device, characterized by applying a probabilistic design including a non-normal distribution to perform a non-normal distribution-based analysis regarding the design value and the test value.
In paragraph 1, The step of calculating the above statistical moment is, A method for calculating a design margin of power equipment characterized by evaluating the reliability of the design value and the test value by applying Reliability Based Design Optimization (RBDO).
In paragraph 1, The step of calculating the above statistical moment is, A method for calculating design margins for power equipment characterized by increasing the efficiency of statistical moment calculations by reducing the dimensionality of design variables through the application of a univariate dimensionality reduction method.
In paragraph 1, The step of calculating the above design margin is, A method for calculating a design margin for a power device, characterized by calculating a design margin corresponding to a constraint including at least one of efficiency, power factor, starting torque, and starting current.
A database section storing design and test values of power equipment; A statistical moment calculation unit that calculates a statistical moment considering uncertainties including design error, manufacturing deviation, and test conditions by performing statistical analysis based on the stored design values and test values; and, A design margin calculation system for power equipment comprising: a design margin calculation unit that calculates a design margin based on the statistical moment calculated above, which minimizes the difference between customer specifications and design values and minimizes the sum of failure costs and product production costs.
In paragraph 8, A system for calculating design margins of power equipment, characterized in that the above statistical moment calculation unit calculates the average value, which is the first moment of the design value and the variance, which is the second moment, of the above design value and test value, and quantitatively analyzes the variability of the performance distribution according to manufacturing deviation.
In paragraph 8, A system for calculating design margins for power equipment, characterized in that the above-mentioned statistical moment calculation unit analyzes the asymmetry and peaking of a performance distribution, including skewness (a third moment) and kurtosis (a fourth moment), by considering a random variable that follows a non-normal distribution.
In paragraph 8, A system for calculating design margins of power equipment, characterized in that the above-mentioned statistical moment calculation unit applies a probabilistic design including a non-normal distribution to perform a non-normal distribution-based analysis regarding the design value and the test value.
In paragraph 8, The above-mentioned statistical moment calculation unit is characterized by applying Reliability Based Design Optimization (RBDO) to evaluate the reliability of the design value and the test value, thereby providing a system for calculating the design margin of a power device.
In paragraph 8, The above-mentioned statistical moment calculation unit is characterized by increasing the efficiency of statistical moment calculation by reducing the dimensionality of design variables through the application of a univariate dimensionality reduction method.
In paragraph 8, A system for calculating design margins of power equipment, characterized in that the above-mentioned design margin calculation unit calculates a design margin corresponding to a constraint including at least one of efficiency, power factor, starting torque, and starting current.

Description

Method for calculating design margin for power devices and system for calculating design margin for power devices The present invention relates to a method for calculating design margins for power equipment and a system for calculating design margins for power equipment. More specifically, it relates to a method for calculating design margins for power equipment and a system for calculating design margins for power equipment that can reduce the number of MH (Man-Hour) required for design and lower the possibility of over-design or under-design during the design process by standardizing and computerizing the calculation of design margins based on design and test data. In general, ensuring reliability while meeting various performance requirements is a critical challenge in power equipment design. In particular, power equipment design is highly susceptible to discrepancies between design values and actual test values due to various uncertainty factors, such as manufacturing tolerances, material inhomogeneities, and changes in the operating environment. Since such differences can degrade performance or cause failures, it is essential to establish appropriate safety margins during the design phase. However, conventional design methods have often relied on fixed standards or the designer's experience when setting design margins. Yet, this approach can lead to unnecessary cost increases by applying excessive margins, or conversely, performance degradation or reliability issues due to insufficient margins. Particularly in power equipment such as electric motors, failure to satisfy constraints—such as starting torque, starting current, efficiency, and power factor—is highly likely to result in reduced performance or unexpected failures. Conventional design methods have limitations in that they fail to simultaneously consider these performance conditions and reliability, and rely excessively on the designer's experience. Consequently, systematic analysis to address uncertainty is not performed, and the difference between design values and test values is not effectively reflected. This problem leads to over-design or under-design in the design of power equipment, resulting in an inability to strike a balance between performance and cost. Therefore, to address the problems arising from existing design methods, the present invention proposes a method for quantitatively analyzing uncertainty based on the statistical moments of design and test values, and evaluating performance distribution and reliability based on this analysis. In this process, by calculating the optimal design margin that satisfies constraints, it will be possible to maintain stable performance while reducing unnecessary costs. FIG. 1 is a flowchart illustrating the process of calculating a design margin of a power device according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a system for calculating a design margin of a power device according to an embodiment of the present invention. Figure 3 is a conceptual diagram illustrating an example of implementing statistical moments based on existing test values and design values. Figure 4 is a conceptual diagram showing the design point where the sum of product production costs and failure costs is minimized. Figure 5 is a conceptual diagram showing the probability of failure based on the difference between the design and test values. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete, and to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art. Throughout the specification, the same reference numerals indicate the same components. FIG. 1 is a flowchart illustrating the process of calculating a design margin of a power device according to an embodiment of the present invention, FIG. 2 is a block diagram illustrating a system for calculating a design margin of a power device according to an embodiment of the present invention, FIG. 3 is a conceptual diagram illustrating an example of implementing a statistical moment based on existing test values and design values. FIG. 4 is a conceptual diagram illustrating a design point where the sum of product production costs and failure costs is minimized, and FIG. 5 is a conceptual diagram illustrating the probability of failure based on the difference between the design and test values. Referring to FIGS. 1 to 5, a method for calculating a design margin for a power device according to one embodiment of the present invention may largely comprise: a step (S110) of preparing a database storing design values and test values of the power device; a step (120) of performing a statis