• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.161-166
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• 2003

This paper proposes a sensorless vector control of interior permanent magnet synchronous motor(IPMSM) using a reduced order observer. This method introduce the auxiliary control inputs that can eliminate the nonlinear term in the electrical equations and realize the linearization of the motor model. The rotor speed estimate with the observer that needs only the q-axis current. The rotor position calculate using the estimated rotor speed. The speed and position control implement with the estimated value. The validity of the proposed scheme is confirmed by various response characteristics.

• Journal of Power Electronics
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• v.13 no.1
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• pp.77-85
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• 2013

This paper proposes a new dead time compensation method of independent six-phase permanent magnet synchronous motors (IS-PMSM). The current of the independent phase machines contains odd-numbered harmonics because of the dead time and the nonlinear characteristics of the switching devices. By using the d-q-n three-dimensional vector analysis, these harmonics can be extracted at the n-axis current. Thus, the current distortion can be compensated by controlling the n-axis current of the IS-PMSM to zero. The proposed method is simple and can be easily implemented without additional hardware setup. The validity of the proposed compensation method is verified with simulations and several experiments.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.501-505
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• 2001

The parallel operation system of UPS is used to increase reliability of power source at critical load. But parallel UPS system has a few defects, impedance is different from each other and circulating current occurs between UPSs, due to line impedance and parameter variation, though controlled by the same synchronization signal. According to such characteristic of parallel UPS, balanced load-sharing control is the most important technique in parallel UPS operation. In this paper, a novel power deviation compensation algorithm is proposed. it is composed of voltage controller to compensate power deviation that be calculated by using active and reactive current deviation between inverters on synchronous d-q reference frame.

• Journal of Power Electronics
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• v.5 no.2
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• pp.129-141
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• 2005

A high-performance robust hybrid speed controller for a permanent-magnet synchronous motor (PMSM) drive with an on-line trained neural-network model-following controller (NNMFC) is proposed. The robust hybrid controller is a two-degrees-of-freedom (2DOF) integral plus proportional & rate feedback (I-PD) with neural-network model-following (NNMF) speed controller (2DOF I-PD NNMFC). The robust controller combines the merits of the 2DOF I-PD controller and the NNMF controller to regulate the speed of a PMSM drive. First, a systematic mathematical procedure is derived to calculate the parameters of the synchronous d-q axes PI current controllers and the 2DOF I-PD speed controller according to the required specifications for the PMSM drive system. Then, the resulting closed loop transfer function of the PMSM drive system including the current control loop is used as the reference model. In addition to the 200F I-PD controller, a neural-network model-following controller whose weights are trained on-line is designed to realize high dynamic performance in disturbance rejection and tracking characteristics. According to the model-following error between the outputs of the reference model and the PMSM drive system, the NNMFC generates an adaptive control signal which is added to the 2DOF I-PD speed controller output to attain robust model-following characteristics under different operating conditions regardless of parameter variations and load disturbances. A computer simulation is developed to demonstrate the effectiveness of the proposed 200F I-PD NNMF controller. The results confirm that the proposed 2DOF I-PO NNMF speed controller produces rapid, robust performance and accurate response to the reference model regardless of load disturbances or PMSM parameter variations.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.3
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• pp.167-178
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• 2010

To diagnose a stator winding fault caused by a short-circuited turn in a permanent magnet synchronous motor (PMSM), an on-line based fault detecting scheme during motor operation is presented. The proposed scheme is based on monitoring the second-order harmonic components in q-axis current obtained through the harmonic analysis and a winding fault is detected by comparing these components with those in normal conditions. The linear interpolation method is employed to determine harmonic data in arbitrary normal operating conditions. To verify the effectiveness of the proposed fault detecting scheme, a test motor to allow inter-turn short in the stator winding has been built. The entire control system including harmonic analysis algorithm and fault detecting algorithm is implemented using DSP TMS320F28335. The proposed scheme does not require any additional hardware and can effectively detect a fault during motor operation so long as the steady-state condition is satisfied.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.832-833
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• 2011

Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, is calculated by LC resonance method with FEM. The results are validated by comparison the calculated by another method.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.524-526
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• 2011

This paper focuses on study on PWM converter control under unbalanced network condition. Voltage unbalance in a three-phase system causes the performance deterioration by producing 120 Hz voltage ripples in the DC link and 120 Hz ripple in reactive power. To eliminate the ripples, both positive and negative sequence currents should be controlled simultaneously. In this paper four PI controllers on synchronous reference frame is implemented to control D and Q currents in both positive and negative sequence. Positive and negative sequence signal extraction is done using delay signal cancellation method. Simulation results show satisfactory performance in suppressing 120 Hz ripples.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.6
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• pp.23-30
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• 2013

This paper shows the method of winding connection and the balance of three phase of dual inverter systems used for offshore wind power generator. In order to satisfy low cost manufacturing of large scaled wind generator, the number of slot per pole per phase should be reduced. For this reason, in this research, the number is selected as '1' which is the minimum number that stator can have. Based on the prototype machine, three types of machine for the analysis are selected, and various performances especially in terms of electrically balanced condition are also investigated. Moreover, in this paper, new inductance modeling of dual 3-phase considering cross-coupling between two inverter systems is proposed. The several inductances such as mutual-, synchronous inductances are studied. By using FEA, based on calculated the flux linkage of d and q-axis, the validity of the proposed inductance modeling is confirmed.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.367-375
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• 2000

It is proposed that the rotor time constant and inductance are compensated at the same time in the indirect vector control method of an induction motor. The proposed scheme compensates the rotor time constant using the difference between the Q-axis real stator current and estimated current that is calculated from the terminal voltage and current, and compensates inductance by using the difference between the D-axis real stator flux and estimated stator flux in the synchronous rotating reference frame. Although the rotor time constant and inductance vary at once, the proposed method compensates the rotor time constant and inductance with accuracy. In addition to, two variables can be compensated not only at the steady state condition, but also at the transient state, where the torque varies in a rectangular pulse waveform. Therefore, the performance of vector control is greatly improved as verified by experiment.

• Journal of Industrial Technology
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• v.33 no.A
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• pp.61-66
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• 2013

This paper is about the development of 80[kW] IPMSM(Interior Permanent Magnet Synchronous Motor) drive system for an electric vehicle. MTPA(Maximum Torque per Ampere) operation and flux-weakening operation for the optimal torque control of the IPMSM are presented. In this system, the torque control of the IPMSM is achieved by using the look-up table, which gives d- and q-aixs current references for the given torque command in the MTPA operation and flux-weakening operation regions. This look-up table is made by current injection tests, and from which the motor parameters are also estimated. The proposed system is verified by the experiment on the electric vehicle drive system, which consists of an 80[kW] IPMSM and an IGBT inverter.