Development of magnetic-wedge linear adjustable reactor

Abstract

Adjustable reactor is an important VAR compensator for AC system, so it has practical significance to do researches on this device. This paper proposed a method of adjusting inductance value based on a controlled magnetic-wedge, which could change the air-gap in the magnetic path by adjusting the depth it inserted. The reactor based on this method was named as magnetic-wedge linear adjustable reactor. Its working principle and inductance's mathematical models were analysed in detail. ANSYS was used to simulate reactor's magnetic field in order to verify the analysis previously. A prototype was made and its inductance's adjustment curve was measured. Results showed that: the inductance's adjustment curve was a piecewise function. When the magnetic-wedge was in positive section, the relationship between inductance and depth of magnetic-wedge inserted was a linear function. If the magnetic-wedge was totally inserted, the air-gap was minimum while inductance was maximum. If the magnetic-wedge was totally pulled out, the air-gap was maximum while inductance was minimum. When the magnetic-wedge was in negative section, the relationship between inductance and magnetic-wedge's position was a double-exponential function, the nearer magnetic-wedge's position was, the more sensitively the inductance changed. Magnetic-wedge could control magnetic flux path and restrain air-gap edge effect.

Keywords

• finite element analysis
• inductance
• reactors (electric)
• magnetic flux
• static VAr compensators
• magnetic path
• magnetic-wedge linear adjustable reactor
• magnetic field
• inductance
• air-gap
• magnetic flux path
• controlled magnetic-wedge