Sliding mode control with open‐switch fault diagnosis and sensorless estimation based on PI observer for PMSM drive connected with an LC filter

Abstract

In some cases, LC filters are installed between the inverters and motors to suppress the adverse effects of pulse width modulation. However, some techniques should be modified, because the mathematical model of the drive system is changed by the LC filter and the sensors on the inverter output cannot measure some necessary variables. In this study, a multipurpose proportional-integral (PI) observer is proposed at first. The type of observer depends on whether the position sensor is equipped. A sliding mode controller for the LC filter based on the observer is presented, therefore improving the dynamic performance. Furthermore, if the position sensor of the rotor is equipped, an open-switch fault diagnostic method is realised by means of the PI observer; if the position sensor is not equipped, the sensorless estimation is realized. The proposed strategies were realised without any additional current/voltage sensors. Experimental results verified the effectiveness of the proposed strategies.

Open‐switch fault diagnosis in voltage source inverters of PMSM drives using predictive current errors and fuzzy logic approach

“…Therefore, the prediction error between the error-free model (4) and model (17) subjected to parameter variation can be obtained as:…”

“…In case of voltage-based approaches, and in order to avoid the use of additional sensors, the residual results from the comparison of the estimated voltage with the reference voltage obtained from the feedback control. Generally, state estimators are employed [10][11][12][13][14][15][16], but PI and model reference adaptive system (MRAS) observers have been also proposed in [17] and [18], respectively.…”

“…Model-based and signal-based methods are also subdivided into voltage-based or current-based algorithms. Modelbased open-circuit fault diagnosis algorithms require the use of observers [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The fault diagnosis process is generally achieved through residual generation.…”

“…The fault diagnosis process is generally achieved through residual generation. Some contributions have proposed observers to estimate motor or grid currents [4][5][6][7][8][9] whereas others have been dedicated to estimate converter's output voltages [10][11][12][13][14][15][16][17][18]. For current-based algorithms, a residual is generated by comparing the measured current with the observed current.…”

A Control Bandwidth Optimized Active Damping Scheme for LC and LCL Filter-Based Converters

“…In the case of a VSC, an LC filter is used to filter out the switching ripple and output a controllable and high-quality voltage source. This is widely used in the motor drive [3], dynamic voltage restorer [4], and uninterruptable power supply [5].…”