scholarly journals New Diagnosis and Fault-Tolerant Control Strategy for Photovoltaic System

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Hassan Abouobaida ◽  
Younes Abouelmahjoub
Keyword(s):  
Control Strategy ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Open Circuit ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Normal Operation ◽  
Switching Frequency ◽  
Point Tracking ◽  
Interleaved Boost Converter

This paper discusses open-circuit fault (OCF) diagnosis and fault-tolerant control strategy (FTCS) of a nonisolated DC-DC converter. The photovoltaic power conversion structure (PPCS) consists of a photovoltaic generator and an interleaved Boost converter (IBC). The maximum power point tracking (MPPT) control of the IBC ensures operation at maximum power. The design of the nonlinear Backstepping control is detailed based on the equivalent average model of IBC, and the stability is studied using Lyapunov’s theorem. The proposed OCF fault detection is based on sampling the voltage across the inductor at a much higher frequency than the switching frequency. In an OCF situation occurrence and a high control signal state, the detection of three negative samples is a condition for signaling the presence of an OCF fault; the photovoltaic system continues its normal operation. The simulation results show the validity of the proposed FTCS. The proposed diagnosis and control strategy improves the performance of the IBC in terms of cost, reliability, and service continuity.

scholarly journals Fault-Tolerant Control Strategy with Asymmetric Phase Currents for Single to Four-Phase Open-Circuit Faults of Six-Phase PMSM

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3163
Author(s):  
Chen Huang ◽  
Lidan Zhou ◽  
Zujia Cao ◽  
Gang Yao
Keyword(s):  
Working Conditions ◽  
Control Strategy ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Open Circuit ◽  
Time Varying ◽  
Electromagnetic Torque ◽  
Control Loops ◽  
Phase Current ◽  
Multi Phase

Multi-phase motors and generators are regarded with great fault tolerance capability, especially on open-circuit faults. Various mathematics analytical methods are applied for their fault control. In this paper, a fault-tolerant control strategy with asymmetric phase current for the open-circuit faults with arbitrary phases in the six-phase PMSM (six-phase permanent magnetic synchronous motor, 6P-PMSM) system, is proposed for better electrical and dynamical performance of the machine. An innovative mathematical model for PMSM under one to four-phase-open circuit faults are established considering the asymmetry of the machine. Combining with time-varying relations in machines’ working conditions, targeted decoupling transformation matrixes of every kind of open-circuit faults are settled by voltage equations under different faults. Modified control strategy with a connection between the neutral point and the inverter’s DC side is presented, which aims at increasing the system redundancy and reducing the amplitude of phase currents. Besides, improved control loops with two layers are put forward as well, with which the PMSM system acquires fewer harmonics in phase current and smoother electromagnetic torque. Simulation and experimental results of open-circuit faults are provided for verification of the theoretical analysis.

Loss Analysis of Three-Level Active Neutral Point Clamped Converter under Fault Tolerance Operation

2012 ◽  
Vol 588-589 ◽  
pp. 847-850
Author(s):  
Wei Jing ◽  
Ran Ding
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Short Circuit ◽  
Phase Relationship ◽  
Open Circuit ◽  
Neutral Point ◽  
Normal Operation ◽  
Switching Frequency ◽  
Continuous Output ◽  
Control Schemes

Compared with traditional three-level neutral-point-clamped (NPC) converter, the recently proposed three-level active NPC (ANPC) converter has the ability to overcome the unbalanced loss distribution, and therefore result in increased output power or switching frequency. In industrial applications, fault tolerance ability of power converters is very important considering system availability, safety and reliability. This paper introduced the control schemes to get stable and continuous output under single device fault for both open-circuit and short-circuit fault cases. By analyzing the phase relationship of reference voltage and load current, the loss calculation method under fault tolerant operation was proposed. Calculation results show that the devices junction temperatures under fault tolerant operation are within the safe operation area (SOA) even they are a little bit higher compared to normal operation, which also confirm the effectiveness of the fault tolerant control schemes.

scholarly journals Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-Phase Open Circuit Fault

2016 ◽  
Vol 7 (4) ◽  
pp. 1061
Author(s):  
Kamel Saleh ◽  
Mark Sumner
Keyword(s):  
Control Strategy ◽  
System Performance ◽  
Single Phase ◽  
Fault Tolerant ◽  
Sensorless Control ◽  
Fault Tolerant Control ◽  
Performance Degradation ◽  
Open Circuit ◽  
Phase Inverter ◽  
Simulation Results

This paper introduces a sensorless-speed-controlled PMSM motor fed by a four-leg inverter in case of a single phase open circuit fault regardless in which phase is the fault. To minimize the system performance degradation due to a single phase open circuit fault, a fault tolerant control strategy that includes taking appropriate actions to control the two remaining healthy currents is used in addition to use the fourth leg of the inverter.  Tracking the saliency is done through measuring the dynamic current responses of the healthy phases of the PMSM motor due the IGBT switching actions using the fundamental PWM method without introducing any modification to the operation of the fourth leg of the inverter. Simulation results are provided to verify the effectiveness of the proposed strategy for sensorless controlling of a PMSM motor driven by a fault-tolerant four-phase inverter over a wide speed ranges under the case of a single phase open circuit.

scholarly journals Improved SVPWM Fault-Tolerant Control Strategy for Five-Phase Permanent-Magnet Motor

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4626 ◽  
Author(s):  
Liang Xu ◽  
Wenxiang Zhao ◽  
Guohai Liu
Keyword(s):  
Permanent Magnet ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Fault Tolerant ◽  
Control Strategies ◽  
Fault Tolerant Control ◽  
Open Circuit ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor

Multiphase permanent-magnet motors have received a lot of attention in the past few years owing to the merits of high power density, high efficiency and high fault-tolerant capability. Particularly, high fault tolerance is very desirable for safety-critical applications. This paper proposes an improved space vector pulse-width modulation (SVPWM) fault-tolerant control for five-phase permanent-magnet motors. First, generalized five-phase SVPWM fault-tolerant control is deduced and analyzed based on single-phase open-circuit fault, thus obtaining various SVPWM fault-tolerant control strategies and yielding a greatly increased capacity to enhance fault-tolerant performance of motor. Then, an improved SVPWM fault-tolerant control strategy with increased DC bus voltage utilization and reduced current harmonics is proposed and compared with the traditional one. Last, effectiveness and superiority of the proposed control strategy is verified by both simulation and experimental results on a five-phase permanent-magnet motor.

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