Zero Voltage Vector Sampling Method for PMSM Three-Phase Current Reconstruction Using Single Current Sensor

To reduce the cost of the inverter system in home appliances, a method using a shunt resistor at the DC-link can be substituted for a method using two current sensors at the inverter output. However, the minimum time of the active vector is required to sample the accurate current using a 1-shunt resistor. Therefore, many studies have been conducted investigating current reconstruction methods in the unmeasurable region of the current. The conventional methods using voltage injection have some problems such as high THD (Total Harmonic Distortion) and acoustic noise, because the PWM pattern is shifted. In addition, the current reconstruction is inaccurate in a low modulation region. In this paper, the cause of the noise in conventional methods is analyzed and a simple current reconstruction method based on an average current estimation and a current reference is utilized for reducing acoustic noise. In an immeasurable area, especially a low modulation region, an intermittent PWM shift method is proposed to enhance the accuracy of the reconstructed current. Therefore, a control strategy that combines all of the mentioned methods is implemented for the entire operating range. The effectiveness of the proposed methods is verified through the experimental results and the results of sound measurement in an anechoic chamber are included to compare with the acoustic noise.

Section: Introductionmentioning

confidence: 99%

A Current Reconstruction Strategy Following the Operation Area in a 1-Shunt Inverter System

Park

Kim

Yeom³

et al. 2019

“…Fixed sampling points are enabled in this method, and it is possible to enlarge the measurable area to almost the whole hexagon of SVPWM diagram, while high THD is induced in the low modulation region. Without modifying the PWM signal, a zero voltage vector sampling method (ZVVSM) [36] was proposed for phase current reconstruction to move the immeasurable regions to the edge of the SVPWM hexagon. However, the practical issues of wiring and choosing the type of current sensor are encountered.…”

Section: Introductionmentioning

confidence: 99%

A Hybrid Fault-Tolerant Strategy for Severe Sensor Failure Scenarios in Late-Stage Offshore DFIG-WT

et al. 2017

Abstract:As the phase current sensors and rotor speed/position sensor are prone to fail in the late stage of an offshore doubly-fed induction generator based wind turbine (DFIG-WT), this paper investigates a hybrid fault-tolerant strategy for a severe sensor failure scenario. The phase current sensors in the back-to-back (BTB) converter and the speed/position sensor are in the faulty states simultaneously. Based on the 7th-order doubly-fed induction generator (DFIG) dynamic state space model, the extended Kalman filter (EKF) algorithm is applied for rotor speed and position estimation. In addition, good robustness of this sensorless control algorithm to system uncertainties and measurement disturbances is presented. Besides, a single DC-link current sensor based phase current reconstruction scheme is utilized for deriving the phase current information according to the switching states. A duty ratio adjustment strategy is proposed to avoid missing the sampling points in a switching period, which is simple to implement. Furthermore, the additional active time of the targeted nonzero switching states is complemented so that the reference voltage vector remains in the same position as that before duty ratio adjustment. The validity of the proposed hybrid fault-tolerant sensorless control strategy is demonstrated by simulation results in Matlab/Simulink2017a by considering harsh operating environments.

“…To reduce cost and volume, as well as to increase reliability in hostile environment [16], technical trends move towards driving power converts with fewer sensors or without sensors. Research to reconstruct three-phase currents using single current sensors, especially in motor drive systems, has been undertaken [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

“…Taking these factors into consideration, a method named zero voltage vector sampling method (ZVVSM) is proposed in [34]. The single hall-effect current sensor is installed in a new position to sample the sum currents of two current flow paths.…”

Section: Introductionmentioning

confidence: 99%

“…Based on the ZVVSM, this paper proposes an extended single current sensor technique used in the three-phase PMSM drive due to the fact that the installation position of the single current sensor in [34] is not a unique way to realize the phase current reconstruction. This paper extends this method by changing the installation position of the single current sensor and sampling the current during the zero voltage vectors.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Phase Current Reconstruction Approach for Three-Phase Permanent-Magnet Synchronous Motor Drive

Yan

Zou

2016

Self Cite

Three-phase permanent-magnet synchronous motors (PMSMs) are widely used in renewable energy applications such as wind power generation, tidal energy and electric vehicles owing to their merits such as high efficiency, high precision and high reliability. To reduce the cost and volume of the drive system, techniques of reconstructing three-phase current using a single current sensor have been reported for three-phase alternating current (AC) control system using the power converts. In existing studies, the reconstruction precision is largely influenced by reconstructing dead zones on the Space Vector Pulse Width Modulation (SVPWM) plane, which requires other algorithms to compensate either by modifying PWM modulation or by phase-shifting of the PWM signal. In this paper, a novel extended phase current reconstruction approach for PMSM drive is proposed. Six novel installation positions are obtained by analyzing the sampling results of the current paths between each two power switches. By arranging the single current sensor at these positions, the single current sensor is sampled during zero voltage vectors (ZVV) without modifying the PWM signals. This proposed method can reconstruct the three-phase currents without any complex algorithms and is available in the sector boundary region and low modulation region. Finally, this method is validated by experiments.