Enhanced Torque Control of a PMSM Supplied by a Four-Leg Voltage Source Inverter Using the Third Harmonic

This paper investigates an electrical drive composed of a four-leg voltage source inverter and a three-phase starconnected surface permanent magnet synchronous machine with concentrated windings. The inverter fourth leg is clamped to the neutral point of the machine. We find the current references leading to smooth torque and maximal torque per ampere operation in the presence of a third harmonic electromotive force component. We further analyze the advantages of the proposed topology in terms of torque increase and dc-link voltage requirements

Fault-Tolerant Operation of an Open-End Winding Five-Phase PMSM Drive with Short-Circuit Inverter Fault

Multi-phase machines are well-known for their fault tolerant capability. Star-connected multiphase machines have fault tolerance in open-circuit. For inverter switch short-circuit fault, it is possible to keep a smooth torque of Permanent Magnet Synchronous Machine (PMSM) if the currents of faulty phases are determined and their values are acceptable. This paper investigates fault-tolerant operations of an open-end fivephase drive, i.e. a multi-phase machine fed with a dual-inverter supply. Inverter switch short-circuit fault is considered and handled with a simple solution. Original theoretical developments are presented. Simulation and experimental results validate the proposed strategy

Control Strategies for Open-End Winding Drives Operating in the Flux-Weakening Region

This paper presents and compares control strategies for three-phase open-end winding drives operating in the flux-weakening region. A six-leg inverter with a single dc-link is associated with the machine in order to use a single energy source. With this topology, the zero-sequence circuit has to be considered since the zero-sequence current can circulate in the windings. Therefore, conventional over-modulation strategies are not appropriate when the machine enters in the flux-weakening region. A few solutions dealing with the zero-sequence circuit have been proposed in literature. They use a modified space vector modulation or a conventional modulation with additional voltage limitations. The paper describes the aforementioned strategies and then a new strategy is proposed. This new strategy takes into account the magnitudes and phase angles of the voltage harmonic components. This yields better voltage utilization in the dq frame. Furthermore, inverter saturation is avoided in the zero-sequence frame and therefore zero-sequence current control is maintained. Three methods are implemented on a test bed composed of a three-phase permanent-magnet synchronous machine, a six-leg inverter and a hybrid DSP/FPGA controller. Experimental results are presented and compared for all strategies. A performance analysis is conducted as regards the region of operation and the machine parameters.Projet SOFRACI/FU

Current sensor fault detection and isolation combining model-based and signal-based algorithms in PMSG drives

This paper presents a new on-line open-phase and current-sensor fault detection and isolation method for permanent-magnet synchronous generator (PMSG) drives with neutral point voltage control. Simple signal processing implementations for sensor outage and open-phase faults detection are combined with a cumulative-sum (CUSUM) algorithm capable of detecting smaller sensor output errors (offset or gain variation). The algorithm uses output signals from eight current sensors (two on each phase and two on the neutral wire). Experimental tests have been done on a 2kW-PMSG at different speeds and braking torques where different sensor-fault combinations have been tested with and without open-phase fault. Finally a test has been done while the shaft speed and the torque were varying in order to test the ability of the algorithm to work in transient conditions. Results show that the algorithm allows 3-out-of-6 redundancy in case of sensor outage and 5-out-of-6 redundancy in case of sensor offset or gain change with globally limited computational cost. Combinations of two outages and one offset or gain error can be isolated. In case of open-phase fault the algorithm can continue to detect sensor faults if at least one sensor is working on each remaining phase and on the neutral. A short fault detection time is obtainedin case of sensor outage with a transitional detection by the CUSUM algorithm followed by the final detection by the signal processing algorithm.info:eu-repo/semantics/publishe

Fault Tolerant Dual-Motor Drives: Sizing of Power Electronic

This paper analyzes two dual-motor fault-tolerant topologies. The first one supplies independently both machines while the second one connects them in series for reducing the number of transistors. For a given DC-link voltage, the converter component sizing is based on the peak current obtained in the normal and degraded modes.CIFFRE - Thales Grou

A Comparative Study of Two Fault-Tolerant Dual-Motor Drive Topologies Under Short-Circuit Inverter Switch Fault

This paper analyzes two dual-motor fault-tolerant topologies for aerospace thruster application. The first structure supplies independently both machines while the second one connects them in series for reducing the number of transistors and offering a capability of energy management between the sources. Inverter short-circuit fault is considered. Based on the peak-currents obtained in simulation in degraded mode without reconfiguration and with two different reconfiguration strategies, the two proposed topologies can be compared in economic and technical aspects

Inverter Fault Diagnosis of an Electrical Series-Connected Two Sinusoidal Six-Phase Permanent Magnet Machines Drive

This paper investigates a real-time fault diagnostic of a transportation system which needs two drives with fault-tolerance capabilities. Because of constraints on the mass of the system and on the cost of the Voltage Source Inverter (VSI), a drive with two Six-Phase Permanent Magnet Synchronous Machines (PMSM) in series-connection supplied by two six-leg inverters is chosen. Despite the serial -connection, independent control of the two machines and fault –tolerance to open-switch fault is ensured. Nevertheless, a Fault Detection Identification (FDI) process is required for analysis and/or control reconfiguration. The proposed FDI is based on the combination of different criteria obtained from the two zero-sequence currents and from the normalized currents mapped into two frames defined by the Concordia Transformation. Results obtained from simulation and experimental tests show the effectiveness of the proposal.Projet CE2

Open Switch Fault Effects Analysis (OSFEA) in Five Phase PMSM Designed for Aerospace Application

This paper describes analytical and simulation tools to analyze the effects of Open Switch Fault (OSF) and Open Phase Fault (OPF) on five-phase PMSM designed for aerospace applications. For these demanding applications, the fault tolerance and the reliability of the PMSM as well as the power converter are of high great importance. The addressed work aims essentially to analyze the dynamic of the measured phase currents in post-fault operation with a real-time fault diagnostic purposes in the VSI. It starts with a presentation of the electric drive system structure and its control used in pre-fault and post-fault operation of the electric drive system. Then, fault mode effects analysis (FMEA) on the system is considered. It is based on the Generalized Vectorial Formalism (GVF) and Space Vector Theory (SVT). All results are verified analytically and through simulation software using Matlab/Simulator®. The theoretical development and the simulation results show that the five phase PMSM under inverter faults presents typical characteristics which can be used as better inputs variable for designing a high performance fault diagnostic and classification process.Project 3M-Tolerant with MEDEE funded by Region Nord-Pas-de-Calai

Open Switch Fault Effects Analysis in Five-Phase PMSM Designed for Aerospace Application

This paper describes analytical and simulation tools to analyze the effects of Open Switch Fault (OSF) and Open Phase Fault (OPF) on five-phase PMSM designed for aerospace applications. For such applications, the fault tolerance and the reliability of the drive (PMSM and the power converter) are important to take into account for design. The addressed work aims essentially to analyze the dynamic of the measured phase currents in post-fault operation with a real-time fault diagnostic purpose in the VSI. The paper starts with a presentation of the electric drive system structure and its control used in pre-fault and post-fault operation. Then, fault effects analysis (FEA) on the system will be considered. All results are verified analytically and through simulation software using Matlab/Simulink®. The theoretical development and the simulation results show that the five-phase PMSM under inverter faults presents typical characteristics which can be used as better input variables for designing a high performance real-time fault diagnostic and classification process.Projet ' 3MTolerant' financé par la région Hauts de Franc

A Comparative Study of Two Fault-Tolerant Dual-Motor Drive Topologies Under Short-Circuit Inverter Switch Fault

This paper analyzes two dual-motor fault-tolerant topologies for aerospace thruster application. The first structure supplies independently both machines while the second one connects them in series for reducing the number of transistors and offering a capability of energy management between the sources. Inverter short-circuit fault is considered. Based on the peak-currents obtained in simulation in degraded mode without reconfiguration and with two different reconfiguration strategies, the two proposed topologies can be compared in economic and technical aspects