Harmonic distribution law and suppression countermeasure Shengli of Oilfield electrical network

Key words:  oilfield electrical network  harmonic distribution  suppression countermeasure

Abstract:

To grasp the harmonic situation of Shengli Oilfield electrical network and propose suppression countermeasures, the bus was studied according to the harmonic injection of usere. Different grid loads，harmonic currents and harmonic voltages of different levels were detected for oilfield electrical network. The results show that variable-frequency energy-efficient devices produce more serious harmonics than the motors. The motors of different types have different effects on harmonics. The motors in descending sequence of influence degree are high-performance switched reluctance speed motor, permanent magnet synchronous motors, induction motors, electromagnetic speed control motor and high slip motors and 6 kV synchronous motors. Voltage harmonic distortion of oilfield electrical network is less than the national standard，which shows that the oilfield power supply network is qualified. The cutTent harmonics of 6 -10 kV line exceed the standard seriously and occupy 34. 5% of the total bus number. Serious harmonics mainly are 5th，7th harmonic, then the 3rd harmonic. The focus of network harmonic suppression is the inhibition of harmonic content of 6 kV power supply system. Active filter is a new type of harmonic compensation devices and can be effective in reducing the inflow of the 3rd, 7th, 11th harmonic.