Medium Voltage Inverter Technology Research And Application In Thermal Power Plant

Pass to discussion three kinds of realize way: the Y-Δ transformation type, high-low-high type, high-high type, make sure that the high-voltage motor realizing of variable frequency regulating speed technique method of #2 unit's of breeze machine in ShengLi power station, namely adopt technique of high-high type in variable frequency regulating speed.Adopted high-high type variable frequency regulating equipment, discovers problem that temperature inside motor essence go up 5-12℃ than not reforming drying circulation. Analyzed to the reason of fever, is that original motor design manufacturing by 50 Hz. when frequency variety, additional exhaust gain, result in the temperature inside motor essence to heat up. More, this paper finds outs relation with variable frequency and coil temperature, bring up the measure that changes cleft of motor, realize result that reduce the heat. It's seen that this measure is feasible and efficacious.High-voltage motor relay protection can be influenced by the variable frequency. According to hid the starting current, soon breaks of electric current relay protection of motor that did not add variable frequency regulating speed equipment settle calculation. But after adopted variable frequency, the starting current of high-voltage motor was reduced more. So the principle of soon breaks settled number should change. It's that when frequency equipment essence occurred breakdown, protected equipment can judge right, and cut off the break down point.