Single-phase Open Circuit Research Articles

Experimental Assessment of Predictive Current Control Applied to Induction Machine Drive Systems Operating Under Single-Phase Open-Circuit Fault


 Predictive Current Control (PCC) has been widely applied in several applications. However, the literature has not discussed its use as a fault tolerance control algorithm in induction drive systems. In this way, this paper discusses the PCC method in two faulttolerant squirrel-cage induction machine drive systems operating under single-phase open-circuit faults. PCC’s postfault performance is compared to Field Oriented Control (FOC) for different steady- and transient-state scenarios, analyzing harmonic distortion, torque ripple, and the transition from healthy to postfault operation. Also, experiments tested the robustness of postfault PCC to low-speed operation, parametric variation, and a step change in reference rotor speed, showing that PCC also presents fault-tolerant operation under these conditions.

Fault-Tolerant Control for Single-Phase Open-Circuit and Short-Circuit Fault in Five-Phase PMSM With Third-Order Harmonic Back EMF Using Coefficients Reconfiguration

Fault-Tolerant Control for Single-Phase Open-Circuit and Short-Circuit Fault in Five-Phase PMSM With Third-Order Harmonic Back EMF Using Coefficients Reconfiguration

Fault-Tolerant Operation for Single-Phase Open Circuit of Dual-Armature Flux-Switching Permanent Magnet Machine by Connecting Neutral Points

Fault-Tolerant Operation for Single-Phase Open Circuit of Dual-Armature Flux-Switching Permanent Magnet Machine by Connecting Neutral Points

Multi-Harmonic Torque Ripple Optimization in Phase Current Reconstructed OW-PMSM Drive with Single-Phase Open-Circuit Fault

Multi-Harmonic Torque Ripple Optimization in Phase Current Reconstructed OW-PMSM Drive with Single-Phase Open-Circuit Fault

Torque Ripple Suppression in the Full Torque Operation Range for Dual Three-Phase PMSM Under Single-Phase Open-Circuit Fault

Torque Ripple Suppression in the Full Torque Operation Range for Dual Three-Phase PMSM Under Single-Phase Open-Circuit Fault

A Novel Fault Tolerance Structure of Arc Linear Flux Switching Permanent Magnet Motors Based on Redundant Winding

This paper presents a novel structure of the arc linear flux switching permanent magnet motor based on the redundant winding to inhibit the rises of the motor losses and temperature due to the open circuit fault tolerance. Firstly, the structural characteristic of the arc linear flux switching permanent magnet motor is introduced. Then, the fault tolerance current of single phase open circuit fault is calculated for different winding connection forms. The fault tolerance performances under different conditions are compared from a special view of motor temperature rises. Finally, a novel structure for fault tolerance enhancement is proposed, which can effectively improve the freedom degree of the fault tolerance current by using the redundant winding. This novel structure takes full advantage of the circumferential air gap between the arc stator. The calculation results show that the novel structure can allow the fault tolerance of open circuit fault has little influence on the motor copper losses and temperature rises while maintaining the on-load torque.

Open-circuit Fault-tolerant Control for Three-phase Permanent Magnet Synchronous Motor

In this paper, a single-phase open-circuit fault-tolerant control method for three-phase permanent magnet synchronous motor (PMSM) is proposed. Based on the 4-leg inverter and the redesigned vector transformation method, the switching of the motor control strategy after a single-phase open circuit can be realized, and the control characteristics of the motor are unchanged. This fault-tolerant control method can be easily combined with other control strategies and has a wide range of applications.

Performance of a vector controlled PMSM drive based on proportional–resonance control under single-phase open circuit fault

In this paper, a vector controlled PMSM drive based on a proportional–resonance controller (PR) under open circuit fault (OCF) is proposed. The PR controller is used to generate the stator voltages. While the field-oriented control (FOC) approach has been implemented using the pulse width modulation (PWM) technology. The simulation is built using MATLAB/ Simulink. Hardware experiments were performed, and the results captured using dSPACE DS1104. The behaviour of the PMSM is studied under three operations: healthy, faulty, and post-fault operation. Moreover, the speed control of the PMSM under the three operations has been presented. The simulation and the experimental results show a fast dynamic response with some ripple in the response of speed and torque during the healthy and post-fault operations. On the other hand, during the OCF, the ripple in the torque and speed response increases. However, the proposed method proves its efficacy by keeping the motor speed nearly at the input reference speed as well as guaranteeing the continued operation of the PMSM with good steady-state and dynamic performance.

A novel speed control strategy for 3-phase induction motor drives with star-connected under single-phase open-circuit fault using modified RFOC strategy

In this research, a novel control method is proposed for 3-Phase Induction Motor (3-PIM) drives with star-connected under Single-Phase Open-Circuit (SPOC) fault using modified Rotor Field-Oriented Control (RFOC) strategy. The standard RFOC strategy is designed based on the d−q model of 3-PIM during normal mode. This strategy cannot be applied for a 3-PIM under SPOC fault as the model of a healthy 3-PIM is different from the model of a faulty 3-PIM. The use of standard RFOC strategy for Vector Control (VC) of a 3-PIM under SPOC fault increases the electromagnetic torque ripples during this fault. To overcome this problem, two unbalanced rotational transformations are used. A Current Transformation Matrix (CTM) is obtained based on the concept of maintaining value of Magnetic Motive Force (MMF) of the faulted machine like the healthy machine. Then, a Voltage Transformation Matrix (VTM) is introduced by using the presented CTM and according to the Single-Phase Induction Motor (SPIM) model. Based on the results, faulted machine RFOC equations were obtained similar to the healthy machine RFOC equations by using the CTM and VTM. The proposed technique was verified by simulations and experiments. Results indicated that the performances of the faulted machine under the proposed RFOC strategy are better than standard control techniques.

OCNOP Control of Grid-Connected Converters for Single-Phase Open Circuit Fault

An open circuit fault-tolerant operation of a grid-connected inverter requires switching reconfigurations or redundant inverter leg to bypass the faulty device. Such measures led to increased cost and design complexities. In the absence of such reconfiguration mechanisms, a grid-connected inverter with an open circuit fault in one of the inverter legs injects negative sequence current into the grid. The negative sequence current causes oscillation in dc-link voltage and thereby injects lower order harmonic into the grid. The present work proposes a novel control strategy (open circuit nonoscillatory power) to deliver a steady power into a balanced three-phase grid with only two active legs of the grid-connected inverter. The current of these two active phases are controlled to be equal in magnitude and 60° phase apart. This inhibits the flow of negative sequence current and in turn limits the lower order harmonic injection within the permissible limit. A control strategy is also proposed to modify the power references during postfault operation so that the postfault current in two active phases are limited within the converter current rating. The performance of the proposed scheme is compared with the conventional vector control scheme through a simulation study. The simulation results for the proposed control scheme are verified through experimental study in a laboratory prototype.

Adaptive Torque Ripple Suppression Methods of Three-Phase PMSM During Single-Phase Open-Circuit Fault-Tolerant Operation

This article proposes adaptive torque ripple suppression methods by utilizing resonant controllers during the single-phase open-circuit fault-tolerant operation of a three-phase star-connected permanent magnet synchronous motor (PMSM). A zero-sequence current is supposed to be injected to maintain the postfault torque the same as the prefault torque. According to the postfault PMSM model, a feedforward voltage compensation can be adopted to inject the zero-sequence currents and, hence, attenuate the postfault speed and torque ripples in the vector control framework. However, the feedforward voltage compensation, which is related to the phase resistance and leakage inductance, may be inaccurate due to the temperature variation, etc., and hence, an unexpected second harmonic torque ripple still exists. In this article, the adaptive suppression methods of the second harmonic torque are proposed. The first one constructs a novel closed current loop of the zero-axis and the second one modifies the controllers in the dq -axis current loop. These methods are based on the resonant controllers, which can adaptively compensate for the voltage needed for the zero-sequence current injection. Experiments are implemented based on a four-leg inverter and the performance comparison between the feedforward compensation and adaptive compensation validates that the proposed methods can effectively suppress the postfault torque and speed ripple.

Harmonic Torque Suppression Methods for Single-Phase Open-Circuit Fault-Tolerant Operation of PMSM Considering Third Harmonic BEMF

This article proposes a novel type of the 2nd and 4th harmonic torque suppression methods during conventional single-phase open-circuit fault-tolerant operation when considering the 3rd harmonic back-EMF of permanent magnet synchronous motor (PMSM). These suppression methods are based on injecting the 3rd harmonic currents into the two remaining healthy phases, which produces harmonic torque of opposite phase to cancel the original one. The suppression can have three different constraints: maintaining the average torque, eliminating the 2nd harmonic torque, and eliminating the 4th harmonic torque. They cannot be achieved simultaneously. Combining any two of them leads to a particular injection method. Three particular methods are developed and their performance are investigated by theoretical analysis and compared against the conventional one. The proposed fault tolerant control strategies are applicable to various fault-tolerant inverter topologies by using these novel phase current references, whereas the current tracking algorithms could be different. To ease validation, a four-leg inverter topology is selected to implement such injection methods to a three-phase star-connected 10-pole/9-slot PMSM. The experiments validate that tracking the proposed current references can effectively suppress the harmonic torque, which confirms the theoretical analysis.

Second-Time Fault-Tolerant Topology and Control Strategy for the Open-Winding PMSM System Based on Shared Bridge Arm

To further improve the fault-tolerant operation capacity of the open-winding permanent magnet synchronize motor system after second-time fault occurring, a novel fault-tolerant topology and a fault-tolerant control strategy for single phase open-circuit is proposed in this article. The fault-tolerant topology proposed in this article can operate stably in case of second-time fault that occurs after one-phase open-circuit fault by the way of sharing a bridge arm. Thus, the fault-tolerant ability of the driving system is further improved. In the terms of control strategy, the amplitude and the phase of the remaining two-phase current are redesigned to keep the system operating steadily according to the conventional expression of motor torque. Moreover, considering that the electromagnetic torque of the system will contain the third harmonic component when the three-phase current is unbalanced, the torque fluctuation will affect the stability of the system. A torque optimization strategy for suppressing the third harmonic component of the torque by injecting corresponding harmonics into the current is proposed. Finally, the experimental results validate the effectiveness of the proposed topology and strategy.

Control Strategy for Single-Phase Open-Circuit Operation of a Modular Solid-State Transformer

The solid-state transformer (SST) has the ability to operate with only two input phases, which can be called single-phase open-circuit (SPO) operation. With this ability, the SST can maintain operation under permanent single-phase-to-ground faults, where the fault phase must be isolated, providing a better power supply sustainability than that of the conventional low-frequency transformer. In the absence of research on the SPO operation of an SST, this paper presents a study of it. The influence of SPO operation on the grid and the SST itself is analyzed. Under the SPO state, the SST will inject the negative-sequence current to the grid; meanwhile, the maximum load power will decline; thus, the optimized power factor under the SPO state is unity. The maximum power of △-SST is higher than that of the Y-SST under the SPO state owing to the △ connection. A control strategy for the SST medium-voltage cascaded H-bridge stage is proposed. SPO current control can be achieved by controlling the positive-sequence current. A proper negative-sequence voltage can be injected to synchronize the cluster voltages to obtain a lower current total harmonic distortion and smaller dc voltage ripple. In the △-SST, a proper zero-sequence current can be injected to fully use the power rating of the double-cluster branch.

Fault-tolerant control of Y-connected three-phase induction motor drives without speed measurement

Fault-Tolerant Control (FTC) in adjustable speed drives under open-circuit faults has been broadly investigated in the literature. Nevertheless, studies in this area have been normally focused on sensored machine drives. This research focuses on the FTC approach for Y-connected Three-Phase Induction Motor (TPIM) drives without speed measurement. An Extended Kalman Filter (EKF) and a Rotor Field Oriented Control (RFOC) system are developed in order to control sensorless speed controlled Y-connected TPIM during both healthy and Single Phase Open-Circuit Fault (SPOCF) conditions. Unlike the conventional sensorless control system, the proposed drive system can be used for the sensorless speed controlled Y-connected TPIM during both normal and SPOCF conditions. The performances of the proposed FTC scheme are implemented on a DSP/TMS320F28335 controller board for a 0.75 kW Y-connected TPIM drive system. Different experimental results are shown to verify the effectiveness and possibility of the introduced technique.

Sensorless Control of a Fault-Tolerant Multi-Level PMSM Drive

This paper presents a new technique to track the saliency position in a permanent magnet synchronous motor (PMSM) post a single phase open-circuit fault. The PMSM is driven by a fault-tolerant multi-level inverter that is utilized to implement a fault-tolerant control strategy to minimize system performance degradation post the fault.The fault-tolerant multi-level inverter is consisting of a number of insulated-gate bipolar transistors (IGBTs). The dynamic current reponses of the PMSM motor due to the switching actions of these IGBTs are used extract the saliency position. This process is not introducing any modification to the operation of the fault-tolerant multil-level inverter as it uses only the fundamental pulse width modulation (PWM) waveform. Moreover,it considers the modifications introduced to the PMSM motor and the multi-level inverter post the fault.Simulation results are provided to verify the effectiveness of the proposed strategy of saliency tracking of a PMSM motor driven by a fault-tolerant four-leg multi-level inverter over a wide range of speeds in the case of a single-phase open circuit fault.

Comparative study of adaptive sliding mode and resonant controllers in fault tolerant five-phase permanent magnet synchronous motor drive

This paper proposes a new fault tolerant control strategy for a five-phase permanent magnet synchronous motor (PMSM) drive under single-phase open circuit condition. The loss of one phase causes problems such as disturbing rotating magneto-motive force (MMF) and generating undesirable torque pulsations. The development of suitable control strategy is a required task in order to ensure disturbance-free operation during post-fault operation. This paper proposes a new control technique for a five-phase PMSM based on adaptive sliding mode control (ASMC) in post-fault under the loss of one stator phase. The proposed method is compared to fault tolerant control strategy based on proportional resonant (PR) controller. The two control strategies are different from theoretical viewpoint proving their abilities to overcome the fault situation with favorable dynamic performance and faster control response of ASMC compared with PR controller. Depicted set of numerical simulation results always shows a close conformity with the developed theoretical background.

Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-phase Open Circuit Fault

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.

Modeling and simulation of sensorless control of four-leg inverter PMSM drives in the case of a single-phase open circuit fault

This paper introduces a new method to track the saliency of a permanent magnet synchronous motor (PMSM) motor fed by a 4-leg inverter in the case of a single-phase open circuit fault through measuring the dynamic current response of the motor line currents due to the insulated-gate bipolar transistor (IGBT) switching actions. In the case of a single-phase open circuit fault, a fault-tolerant control strategy that includes taking appropriate actions to control the 2 remaining healthy currents results in minor system performance degradation. The new strategy introduced in this paper includes software modications only to the saliency tracking algorithm used in healthy mode in order to make it applicable to the recongured converter in the presence of a fault. The new method uses only the fundamental pulse width modulation (PWM) waveform (i.e. there is no modication to the operation of the 4-leg inverter), similar to the fundamental PWM method proposed for a 3-leg inverter. Simulation results are provided to verify the effectiveness of the proposed strategy of saliency tracking of a PMSM motor driven by fault-tolerant 4-phase inverter over a wide range of speeds under the case of a single-phase open circuit fault.

Wavelet Transform Based Fault Diagnosis of BLDC Motor Drive

Due to the development in science and technology tremendous improvement in solid state devices and circuits, so we need to reduce the complexity of control circuits. The Brushless DC Motor (BLDCM) has simple construction, stator consists of winding and rotor consists of permanent magnet. It has higher efficiency and high speed range. In this paper presents the vibration analysis of single phase open circuit fault conditions and the signals are extracted from the Discrete Wavelet Transform (DWT). The Spartan-6 FPGA processor was implemented due to their high performance of the control applications in recent decades. In this process Sinusoidal Pulse Width Modulation (SPWM) techniques were used to control the speed of BLDC Motor. The experimental analysis is carried out in 3phase, BLDCM drive. The vibration signals are measured by using Accelerometer through Lab VIEW software. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.7967