High-dimensional random matrix-based electronic type transformer error state evaluation method

Abstract

The invention discloses a high-dimensional random matrix-based electronic type transformer error state evaluation method, and aims to perform error state evaluation by means of determining whether statistical distribution of the measurement error of the electronic type transformer has abnormal changes or not based on the high-dimensional random matrix only according to the output of the electronic type transformer, without depending on a standard tool or a physical model. The error state evaluation method specifically comprises the steps of establishing the random matrix through the output data of the electronic type transformer based on a sliding time window; expanding the random matrix based on a Kalman filter; solving a non-Hermitian matrix; performing evaluation on matrix solving; and performing evaluation index calculation on a sample central moment and a sample original moment to carry out the electronic type transformer error state evaluation. Effective evaluation on the error state of the electronic type transformer can be carried out under the premise of not depending on the standard tool or the physical model; and the evaluation result is accurate and visualized, and the evaluation method is universal, effective and can be realized easily.

Description

technical field [0001] The invention belongs to the field of state evaluation and fault diagnosis of power transmission and distribution equipment, and more specifically relates to a method for evaluating the error state of an electronic transformer based on a high-dimensional random matrix. Background technique [0002] Power transformers provide accurate and reliable current and voltage signals for power system protection, control, and measurement, and their errors and reliability are closely related to the safe and reliable operation of power systems. With the development of my country's electric power industry, the capacity of the power system is increasing, and the voltage level is also increasing. The traditional electromagnetic transformer has exposed a series of shortcomings: (1) large volume and weight; (2) complex insulation structure; (3) Inherent phenomena such as magnetic saturation and ferromagnetic resonance; (4) Narrow frequency band and poor transient charact...

AI Technical Summary

Problems solved by technology

With the development of my country's electric power industry, the capacity of the power system is increasing, and the voltage level is also increasing. The traditional electromagnetic transformer has exposed a series of shortcomings: (1) large volume and weight; (2) complex insulation structure; (3) Inherent phenomena such as magnetic saturation and ferromagnetic resonance; (4) Narrow frequency band and poor transient characteristics; (5) The analog output of 100V or 5A does not meet the development needs of the primary signal digitization of smart substations

However, there are still several significant problems in the operation of electronic transformers: (1) the error of some electronic transformers drifts during operation, which affects the use of protection, control, metering and measurement functions; (2) ) The error state of the electronic transformer is unknown to the user during the operation process. Only during the maintenance period, the electronic transformer can be calibrated offline using standard instruments, and the error state evaluation in the online situation is difficult to achieve

However, this method has the following shortcomings: (1) The comparison "standard" of this evaluation method is actually people's experience, that is, the output signal of the electronic transformer should not change suddenly under normal conditions, and this condition is in practical application (2) This evaluation method cannot rule out the impact of a grid disturbance, that is, the premise of an accurate judgment is that there is no fault on the primary side of the grid; (3) This evaluation method is more effective for electronic transformer error mutation faults , but the judgment of error gradient faults is relatively weak

However, this method has the following shortcomings: (1) The evaluation of the error state is highly dependent on the accuracy of the established model, and it is usually difficult to construct an accurate mathematical and physical model; (2) The assumptions and simplified conditions in the modeling process affect the accuracy of the evaluation results. Accuracy and reliability, and there is a gap between the accuracy requirements of electronic transformer error assessment

However, this method has the following disadvantages: (1) It is necessary to add equipment in the substation, which is not universal in engineering applications; (2) the premise of the application of this method requires the error of the traditional electromagnetic transformer to meet the accuracy requirements, However, its error state is also unknown during operation

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