| Along with the rapid popularization of power electronic units, harmonic pollution to power network is getting more and more serious and the quality of electric energy is declining. In the recent 20 years, harmonic control and analysis has already been a hotspot in electrotechnics. Lots of excellent research productions about harmonic came forth.The paper set out from practice, we measured the harmonic in the power network of 360 kilo-tons Caustic Soda and EDC Plant, according to the results, and then used harmonic impedance method to analyze the power system, to find whether or not the resonance will happen. Because many reasons could make the harmonic of the power system change such as switching off one feed line or switching off power transformer or switching on or off one high voltage motor etc. In order to get the harmonic impedance data, we calculated the harmonic impedance in different conditions and also used MATLAB software tool to scan the result to find the point of resonance, which indicated that harmonic impedance method can be rightly applied in harmonic analysis engineering as well as which could improve the system .The safety and reliability of this system are proved via analysis; meanwhile, we can conclude when we design an electrical system with high power harmonics, not only the harmonics and relevant restraint, the resonance between compensators or filters and system impedance shall be taken into account; then the evaluation for the system is objective and unabridged. |
