Power transformer core looseness fault on-line monitoring method is introduced
Power transformer core looseness fault monitoring method is introduced in 2019 - online 03 - 30 15:06:10 power transformer is the key equipment in power system, carries on the reliable condition monitoring and fault diagnosis has been brought to the attention of the people. Power transformer core online monitoring method based on vibration analysis as a new method, has obtained certain research results recently. Core as the main components of the transformer is one of the main components of transformer faults, is also the main vibration source of transformer, use of the vibration characteristics of monitoring is to realize the on-line monitoring and fault diagnosis of power transformer vibration is a basic content, has the important realistic meaning, thus obtained a relatively extensive research. Rusov use every harmonic and fractional harmonic reflected a total of about 30 parameter calculation core clamping force of clamping force coefficient; Brook, such as using wavelet packet analysis method based on the change of the frequency band energy criterion for iron core fault signal; Bartoletti etc. At the same time, use of sound and vibration data of core and winding with weighted methods such as constructing harmonic parameters for classification of the different states of transformer; Garcia on large transformer core vibration under different voltage has carried on the comprehensive test, and analyzed the influence factors of its vibration, to construct the mathematical model based on Fourier analysis laid a foundation. Wei-hua xiong etc with Hilbert & middot; The energy spectrum of huang transform on the basis of the changes in the core of failure state. These methods are basically when using the iron core of the harmonic energy or the change of frequency band energy of iron core of the state and fault analysis and diagnosis. Due to the actual situation of core mechanical failure often and there is no clear correlation between the change of vibration energy, makes the accuracy of these methods have certain limitations. Iron core in the magnetostrictive force and electromagnetic force produced under the stimulus of vibration, the mechanical structure has a great influence on its vibration and electromagnetic force. Core is to use silicon steel sheet pile and clamping piece of fastening, usually iron core lamination clearance and even joint clearance is uneven, resulting in internal magnetic field distribution, core and core lamination between the complex electromagnetic force. In non-uniform electric magnetic and magnetostrictive force, under the action of iron core lamination in vibration will occur in the process of collision and friction, make the core vibration produces the impact of the high frequency components, and these shocks components associated with the compaction force of iron core. And signal energy is different, four order statistics kurtosis reflects the signal of the steep, apply to the shock signal analysis, early had been used in rotating machinery fault detection. Based on kurtosis of core study and analysis of vibration signal, puts forward a kind of can change for power transformer core clamping force and cause looseness fault on-line monitoring methods.