• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.99-100
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• 2016

In a AC motor used by three phase inverter, the phase current must be measured to control instantaneous torque. It is expensive to use current sensor for measuring current in low cost motor. So, shunt resistor is used to measure current. But, the method sensing the phase current using shunt resistor cannot perform the vector control in high speed because of the area that impossible to restore three phase current. In this paper, predictive current is proposed for reconstructing the current in the impossible current sensing area that reduce the current ripple in TSSI(Three shunt sensing inverter) for PMSM.

• Journal of Power Electronics
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• 제13권2호
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• pp.232-242
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• 2013

To obtain phase currents information in AC drives, shunt sensing technology is known to show great performance in cost-effectiveness and therefore it is widely used in low cost applications. However, shunt sensing methods are unable to acquire phase currents in certain operation conditions. This paper deals with the derivation of the boundary conditions for phase current reconstruction in three-shunt sensing inverters and proposes a voltage injection method to expand the measurable areas. As the boundary conditions are deeply dependent on the switching patterns, they are typically analyzed on the voltage vector plane for space vector pulse width modulation (SVPWM) and discontinuous pulse width modulation (DPWM). In the proposed method, the voltage injection and its compensation are conducted within one sampling period. This guarantees fast current reconstruction and the injected voltage is decided so as to minimize the current ripple. In addition to the voltage injection method, a sampling point shifting method is also introduced to improve the boundary conditions. Simulation and experimental results are presented to verify the boundary condition derivation and the effectiveness of the proposed voltage injection method.

• 전력전자학회논문지
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• 제22권2호
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• pp.175-180
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• 2017

The measurement of three-phase current is important to control the instantaneous torque of a interior permanent magnet synchronous motor(IPMSM) using a three-phase inverter. Therefore, shunt resistors are used in low-cost motor-driving systems to measure three-phase current instead of additional current sensors that are too expensive for these systems. However, in certain regions of a space vector plane, shunt resistors cannot reconstruct three-phase current in high-speed driving mode. In this paper, predictive current control is used to compensate for the three-phase current in those regions, which results in a reduction of current ripple in a three-shunt sensing inverter(TSSI) and torque ripple in IPMSM.

• Journal of Power Electronics
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• 제16권5호
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• pp.1791-1801
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• 2016

This paper considers a carrier based signal injection method for use in the three shunt sensing inverter (TSSI) for sensorless motor control. It also analyzes the loss according to the injection axis of the voltage signal. To remove both the phase current and rotor position sensors, a sensorless method and a phase current reconstruction method can be simultaneously considered. However, an interaction between the two methods can be incurred when both methods inject voltage signals simultaneously. In this paper, a signal injection based sensorless method with the 120° OFF Discontinuous PWM (DPWM) is implemented in a TSSI to avoid this interaction problem. Since one leg does not have a switching event for one sampling period in the 120° OFF DPWM, the switching loss is altered according to the injection axis. The switching loss in the d-axis injection case can be up to 32% larger than that in the q-axis injection case. Other losses according to the injection axis are also analyzed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.235-236
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• 2011

본 논문에서는 세 개의 Shunt 저항을 이용하여 3상 인버터의 상전류를 검출하였다. Shunt 저항을 이용할 경우 전류 검출이 불가능한 제한 영역이 발생한다. 이러한 제한영역을 보상하기 위해 제한영역에 대하여 분석하였으며, 제한 영역은 추가적인 전류 추정방법을 이용하여 보상하였다. 이를 시뮬레이션을 통하여 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.306-307
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• 2010

본 논문에서는, 동기 전동기 구동을 위해 Three Shunt Resistor를 이용하여 전류를 피드백 받는 방법에 대하여 분석한다. 특히 Three Shunt Resistor를 이용하여 전류를 피드백 받는 경우 Modulation Index (MI)의 크기에 따라 피드백 받은 상전류 정보의 왜곡이 발생하는 문제점에 대하여 분석하고 이를 해결하기 위한 새로운 방법을 제안하며, 컴퓨터 시뮬레이션을 통하여 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.224-225
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• 2016

매입형 영구자석 전동기에 가격과 부피를 줄이기 위해 3개의 션트 저항을 이용하는 인버터를 사용하였고 회전자 위치센서를 제거하기 위해 모델기반 센서리스 기법을 사용하였다. TSSI (Three Shunt current Sensing Inverter)의 문제점인 특정 전압 이상에서는 전류를 검출할 수 없는 영역이 생기게 된다. 이를 예측전류를 사용하여 전류복원 불가영역을 개선하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.211-212
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• 2012

This paper proposes a single current sensor control technique for controlling motors that use only a single DC-Link current sensing resistor to obtain the information of three line currents. However, the measurement is distorted due to the too narrow current pulse width in the shunt resistor. To solve this problem, the existing phase current reconstruction methods are voltage split methods. They have a disadvantage which makes noise. A new dedicated observer is applied to decrease noise problem. Experimental results showed the effectiveness of the proposed method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.208-209
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• 2017

When controlling a three-phase inverter that drives AC motor, it is important to know the value of the current. In this case, shunt sensing methods are known as low cost and useful performance. However, for certain swithcing condition, immeasurable areas exist and it is necessary to reconstruct the current in the area. This paper proposes a reconstruction method using voltage injection in synchronous coordinates system at the area, and verify the validity of the method through simulation.