• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.8
• /
• pp.1355-1361
• /
• 2016

The inter-turn fault (ITF) causes the negative sequence components in the d -q voltage equation due to an increase in the unbalance of three-phase input currents. For this reason, d -q voltage equation become complicate as the voltage equation is classified into positive and negative components. In this study, we propose a simplified d -q equivalent circuit of an interior permanent magnet synchronous motor under ITF state. First, we proposed modeling method for d -q current based on the finite element method simulation results. Then, we developed the simplified d -q equivalent circuit by applying the proposed d -q current modeling.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.17 no.6
• /
• pp.546-552
• /
• 2012

This paper presents an active anti-islanding detection method using negative sequence voltage injection to the grid through a three-phase photovoltaic inverters. Because islanding operation mode can cause a variety of problems, the islanding detection of grid-connected photovoltaic inverter is the mandatory feature. The islanding mode is detected by measuring the magnitude of negative sequence impedance calculated by the negative sequence voltage and current at the point of common coupling. Simulation and experimental test are performed to verify the effectiveness of the proposed method which can detect the islanding mode in the specified time. The test has been done in accordance with the condition on IEEE Std 929-2000.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.7
• /
• pp.357-362
• /
• 1999

This paper presents a speed control method for the capacitor-run induction motor. The equivalent circuit of the motor is analyzed using the forward(Positive sequence) and backward(negative sequence) components, and simple circuit equations are obtained. Simulations for the speed control are performed by adjusting the voltage magnitude of the auxiliary winding. A prototype system has been implemented which consists of an inverter and a controller with TMS320C31 digital signal processor. The experimental results using 1/4hp capacitor-run induction motor show a good agreement with analyses.