A Harmonic Evaluation Of Huizhou Power Supply Bureau On Iron And Steel Enterprise Users Accessing To The Grid

With the rapid development of power electronic technology, power electronicsdevice is also rapidly blent into the modern social production and life, making thevariable frequency speed regulating device such as the rectifier and nonlinear loadsuch as electric arc furnace increased quickly, eventually in the power system theharmonic problem is more and more serious and power quality has serious decline.All that had threatened the power system safe and economic operation and electricalequipment. At the same time, the development of the society and the improvement ofpeople’s living standards as well as extensive application of high-tech put forwardhigher requirements for power system of power quality. So the harmonic governanceand the improvement of power quality are the key research in modern power system.As the large power user, power consumption of iron and steel enterprise accountsfor about10%of the electricity in the whole society, but in its high power distributionsystem of production line, there are a large number of nonlinear, impact load, such aswelding machine and mill. These variable frequency speed regulating devices, highpower thyristor rectifier devices and metallurgical furnace inevitably produce higherharmonic at work, leading to power waveform distortion, making the utility grid andplant distribution network power quality worse, resulting to energy waste andpollution of power. The more serious may affect the normal power supply of otherequipment, causing the damage of equipment and power system accidents. So theintermediate frequency furnace and electric arc furnace used in iron and steelenterprise have became one of the most important harmonic source in power system,is the key object of governance.This paper exampled a certain iron and steel enterprises of huizhou grid connectionas the background. Firstly briefly describes load type and load characteristics of the ironand steel enterprise and the influence on the grid. Secondly makes the load powerquality of iron and steel enterprises monitoring, analysis and assessment, in order toevaluate the power quality problems caused by the steel companies connected to the electricity grid more accurately. Thirdly makes power supply transformer substationmonitoring and evaluation. Finally uses transient simulation software PSCAD/EMTDCpower as a platform, set up load model of iron and steel corporation, carrys onsimulation of the grid to the iron and steel enterprise, and then access grid harmonicimpact evaluation of iron and steel enterprise, put forwards the suggestion of harmonicgovernance measures.