Six-switch Three-phase Inverter Research Articles

Dual-Vector-Based Predictive Torque Control for Fault-Tolerant Inverter-Fed Induction Motor Drives With Adaptive Switching Instant

Four-switch three-phase inverter (FSTPI) is widely applied as a fault-tolerant topology of six-switch three-phase inverter (SSTPI) with an open-phase fault or as a cost-effective topology due to the reduced semiconductor power switches. However, conventional single-vector-based predictive torque control (SV-PTC) for FSTPI-fed induction motor (IM) presents poor steady-state performance and requires high sampling frequency. To address these issues, a dual-vector-based PTC (DV-PTC) for FSTPI-fed IM with adaptive switching instant is proposed in this article. Therein, two optimal voltage vectors are determined in each sampling period, and a simplification strategy for selecting the optimal voltage vectors is established. A switching instant adaptation scheme is developed to improve the steady-state performance of machine control. An optimized overmodulation strategy is proposed to improve the transient-state performance of machine control and reduce the computational burden in digital implementation. Extensive experimental studies validate the effectiveness and superiority of the proposed DV-PTC scheme.

Modulated Model Predictive Torque Control for Fault-Tolerant Inverter-Fed Induction Motor Drives With Single DC-Link Voltage Sensor

Four-switch three-phase inverter (FSTPI) is widely used as a cost-effective fault-tolerant topology of six-switch three-phase inverter with an open-phase fault. To solve the inherent dc-link capacitor voltage offset (CVO) issue of FSTPI, two dc-link capacitor voltage sensors are required in conventional model predictive torque control (MPTC) strategies. To improve the reliability and reduce the cost of induction motor (IM) drives, a modulated MPTC (M-MPTC) for FSTPI-fed IM with single dc-link voltage sensor is proposed in this article. Therein, the relationship of the CVO and the load current is established to obtain the fundamental component of CVO. The two capacitor voltages are reconstructed by single dc-link voltage sensor and the fundamental component of CVO. To suppress the CVO, a cost function that only contains the output voltage vector is designed. The inner relationship between the proposed M-MPTC with single dc-link voltage sensor and the conventional M-MPTC with two dc-link voltage sensors is derived. To retain the load current within the allowed range, a current constraint scheme is proposed and integrated into the M-MPTC. Various simulation and experimental studies are carried out to verify the effectiveness of the proposed strategy.

A NEW MULTI-MOTOR DRIVE SYSTEM BASED ON FOUR-SWITCH THREE-PHASE INVERTER TOPOLOGIES

Vietnam encourages greenhouse technology applications for high-tech agricultural production. The microclimate of greenhouses is the key factor for better plant growth. The greenhouse microclimate can be improved by control actions, such as heating, ventilation, and carbon dioxide enrichment to provide appropriate environmental conditions for crops. The multi-motor drive systems using six-switch three-phase inverter topologies are applied for greenhouse fans. In order to decrease to size and cost of effectiveness drive systems, the paper proposes a new multi-motor drive system based on four-switch three-phase inverter topologies which are applied to two-level hysteresis current controllers. The proposed solution has been tested to a four-permanent-magnet synchronous motor (PMSM) drive system. The simulation results are carried out to show the effectiveness of the proposed solution.

Performance investigation of an advanced diagnostic method for SSTPI-fed IM drives under single and multiple open IGBT faults

PurposeThis paper aims to analyze and investigate the performance of an improved fault detection and identification (FDI) method based on multiple criteria, applied to six-switch three-phase inverter (SSTPI)-fed induction motor (IM) drives under both single and multiple open insulated-gate bipolar transistors(IGBT) faults.Design/methodology/approachThis paper proposes an advanced diagnostic method for both single and multiple open IGBT faults dedicated to SSTPI-fed IM drives considering five distinct faulty operating conditions as follows: a single IGBT open-circuit fault, a single-phase open-circuit fault, a non-crossed double fault in two different legs, a crossed double fault in two different legs and a three-IGBT open-circuit fault. This is achieved because of the introduction of a new diagnosis variable provided using the information of the slope of the current vector in (α-β) frame. The proposed FDI method is based on the synthesis and the analysis, under both healthy and faulty operations, of the behaviors of the introduced diagnosis variable, the three motor phase currents and their normalized average values. Doing so, the developed FDI method allows a best compromise of fast detection and precision localization of IGBT open-circuit fault of the inverter.FindingsSimulation works, carried out considering the implementation of the direct rotor flux oriented control in an IM fed by the conventional SSTPI, have proved the high performance of the advanced FDI method in terms of fast fault detection associated with a high robustness against false alarms, against speed and load torque fast variations and against the oscillations of the DC-bus voltage in the case of both healthy and faulty operations.Research limitations/implicationsThis work should be extended considering the validation of the obtained simulation results through experiments.Originality/valueDifferent from other FDI methods, which suffer from a low diagnostic effectiveness for low load levels and false alarms during transient operation, this method offers the potentialities to overcome these drawbacks because of the introduction of the new diagnosis variable. This latter, combined with the information provided from the three motor phase currents and their normalized average values allow a more efficient detection and identification of IGBT open-circuit fault.

Direct Torque and Flux Control of a Four-Switch Three-Phase Inverter-Fed Synchronous Reluctance Motor Drives

This paper presents an application of direct torque and flux control (DTFC) for a four-switch three-phase inverter (FSTPI)-fed synchronous reluctance motor (SynRM) in which the saturation and iron losses' effects are involved in the machine control modeling. The DTFC switching technique for the SynRM fed by FSTPI in low-power and low-cost applications is implemented by imitating the six-switch three-phase inverter (SSTPI). By considering equal effective vectors depicted in SSTPI, the αβ stationary reference frame is represented by using six sectors. Similarly, the voltage space vector formation is constructed in FSTPI. Accordingly the SynRM performance under DTFC is precisely analyzed by considering the saturation and iron losses' effects. The DTFC behavior based on SSTPI- and FSTPI-fed SynRM is evaluated using Simulink benchmark. At different operating conditions, further simulation and experimental results of DTFC based on FSTPI dynamically confirm the effectiveness of the proposed control application on the SynRM.

A Performance Investigation of a Four-Switch Three-Phase Inverter-Fed IM Drives at Low Speeds Using Fuzzy Logic and PI Controllers

This paper presents a speed controller using a fuzzy-logic controller (FLC) for indirect field-oriented control (IFOC) of induction motor (IM) drives fed by a four-switch three-phase (FSTP) inverter. In the proposed approach, the IM drive system is fed by an FSTP inverter instead of the traditional six-switch three-phase (SSTP) inverter for cost-effective low-power applications. The proposed FLC improves dynamic responses, and it is also designed with reduced computation burden. The complete IFOC scheme incorporating the FLC for IM drives fed by the proposed FSTP inverter is built in MATLAB/Simulink, and it is also experimentally implemented in real time using a DSP-DS1103 control board for a prototype 1.1-kW IM. The dynamic performance, robustness, and insensitivity of the proposed FLC with the FSTP inverter-fed IM drive is examined and compared to a traditional proportional-integral (PI) controller under speed tracking, load disturbances, and parameters variation, particularly at low speeds. It is found that the proposed FLC is more robust than the PI controller under load disturbances, and parameters variation. Moreover, the proposed FSTP IM drive is comparable with a traditional SSTP IM drive, considering its good dynamic performance, cost reduction, and low total harmonic distortion (THD).

QUASI Z-SOURCE NETWORK BASED CONTROL SCHEME FOR FSTP BLDC MOTOR

The paper proposes a novel four switch three phase BLDC motor control scheme which boosts the voltage level, extends the range of speed as well as reduces output torque ripple. The additionally partial circuits of quasi Z-source network and the bridge arm of four-switch inverter constitute the quasi Z-source converter. During the operation of motor, shoot through states are inserted. Then the input voltage of inverter increases and the performance of motor can be markedly improved. The dynamic performance of current is influenced and the speed is limited, for the irregular dc-link voltage utilization in the control of four-switch three-phase (FSTP) BLDC motor. This project presents a novel topology, which combines quasi Z-source converter and FSTP drive circuit. The drawbacks of FSTP BLDC motor are analyzed, the control methods of each mode in quasi Z-source four-switch three-phase (QZFSTP) topology are illustrated. Simulations for QZFSTP BLDC motor were constructed in MATLAB/Simulink circumstance. We can provide an alternate strategy to control BLDC motor by using Four Switch Three Phase inverter. FSTPI helps reduction in switching losses, gate drive requirements, circuit cost and computational time. At low power application, FSTPI fed BLDC motor drives are more suitable than SSTPI (Six Switch Three Phase Inverter). Also reconfiguration of these three leg inverter to FSTPI, in case of switch or leg failure can be done. In proposed system losses are minimizing due to FSTPI because there is reduction in switching losses and also due to Quasi Z-source Inverter output voltage is boosting hence output results were better. To overcome the ripple in torque and distortion in current the QZFSTP BLDC motor control scheme is proposed.

Implementation,Simulation of Four Switch Converter Permanent Magnet Brushless DC Motor Drive for Industrial Applications

This Research paper proposes a low cost four switch three phase inverter (FSTPI) fed brushless DC (BLDC) motor drive for Active power factor correction for residential applicationswith out environmental issues. This proposed system is simplified the topological structure of the conventional six switch three phase inverter (SSTPI) and includes an active power factor correction in front end rectifier which results in sinusoidal input current and it closed to unity power factor. In this project a new structure of four switch three phase inverter with reduced number of switches for system is introduced. This system consists of single phase rectifier and four switch three phase inverter. This proposed inverter fed BLDC motor used in Sensorless control schemes. To improve sensorless control performance, six commutation modes based on direct current controlled PWM scheme is implemented to produced the desire Torque-Speed characteristics. This four switch three phase inverter is achieved by the reduction of switches, low cost control and saving of hall sensor. The design and implementation of low cost four switch inverter for Brushless motor drive with active power factor correction have been conducted successfully and valediction of the proposed sensorless control for four switch three phase inverter fed BLDC motor drive is developed and analysed using both MATLAB/SIMULINK and hardware results are verified out successfully.

Two‐vector‐based modeless predictive current control for four‐switch inverter‐fed synchronous reluctance motors emulating the six‐switch inverter operation

This Letter presents a novel modeless predictive current control (PCC) based on two vectors for a synchronous reluctance motor (SynRM) drive system fed by a four-switch three-phase (FSTP) inverter. In each sampling period, two voltage vectors generated by the FSTP inverter are applied to emulate the operation of a six-switch three-phase inverter. Unlike model-based approaches, the proposed method is modeless, meaning that it does not require a system model or its parameters nor the capacitor voltage. For comparison purpose, both model-based and modeless PCCs are realised on a FSTP inverter-fed SynRM drive system via a 32-bit digital signal controller to contrast their current-tracking performances.

Experimental investigation of a speed‐sensor‐less IM drive system under Inverter fault‐tolerant control

This paper proposes an algorithm for fault tolerance of three‐phase, inverter‐fed, speed‐sensor‐less control of a three‐phase induction motor drive system. The fault tolerance of the inverter when one switch is open or one leg of six‐switch inverter is lost is considered. The control of the drive system is based on indirect rotor field‐oriented control theory. Also, the speed estimator is based on model reference adaptive system (using stator current and rotor flux as state variables for estimating the speed). The fault‐tolerant algorithm is able to adaptively change over from a six‐switch inverter to a four‐switch inverter topology when a fault occurs; also, it makes a smooth transition of the motor speed, torque, and current when changing over from a faulty condition to a new healthy status, which is four‐switch three‐phase inverter (FSTPI) topology; thus, the six‐switch three‐phase inverter (SSTPI) topology (pre‐fault status) is almost retained for the medium‐power range of induction motor applications. The proposed algorithm is simulated by using the MATLAB/SIMULINK package. Also, the proposed control system is tested experimentally using a digital signal processor (DSP1104). The obtained results from the simulation model and experimental system demonstrate the performance enhancement and good validity of the fault‐tolerance control for the speed‐sensor‐less induction motor drive system. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Design and Implementation of Six Switch Three Phase Inverter BLDC Motor Drive for Commercial Applications

This paper proposes a six switch three phase inverter (SSTPI) fed BLDC motor drive for commercial applications. BLDC motor having high efficiency, compact size, rugged construction, reduces mechanical strength, high dynamic response. The 120 degree mode generation used for switching the SSTPI. Thereby, the speed adjustment of three phase BLDC motor drive can be easily obtained. The objective of using SSTPI for three phase BLDC motor drive is that the third harmonics and its corresponding multiples are carried out in the output and ripple voltages is less comparing to single phase inverter. This proposed system is developed for commercial applications such as refrigerators, air conditioning systems, CPU cooling fans, CD/DVD players. This type of three phase BLDC motor drive system is developed and analyzed using MATLAB/SIMULINK in which effective results can be carried out successfully.

Predictive Torque Control Scheme for Three-Phase Four-Switch Inverter-Fed Induction Motor Drives With DC-Link Voltages Offset Suppression

The four-switch three-phase (B4) inverter, having a lower number of switches, was first presented for the possibility of reducing the inverter cost, and it became very attractive as it can be utilized in fault-tolerant control to solve the open/short-circuit fault of the six-switch three-phase (B6) inverter. However, the balance among the phase currents collapses due to the fluctuation of the two dc-link capacitor voltages; therefore, its application is limited. This paper proposes a predictive torque control (PTC) scheme for the B4 inverter-fed induction motor (IM) with the dc-link voltage offset suppression. The voltage vectors of the B4 inverter under the fluctuation of the two dc-link capacitor voltages are derived for precise prediction and control of the torque and stator flux. The three-phase currents are forced to stay balance by directly controlling the stator flux. The voltage offset of the two dc-link capacitors is modeled and controlled in the predictive point of view. A lot of simulation and experimental results are presented to validate the proposed control scheme.

Open-Delta Three-Phase Inverter Current Control Using Predictive Control For PV System Connected To The Grid

Abstract. Predictive control method has advantages such as simple structure, functional and follow the simple mathematical. In this paper, a new method is provided for controlling the open-Delta three-phase inverter . Model-based predictive control system is used for controlling the current of a open-Delta three-phase inverter, which is in the process of converting the photovoltaic energy conversion plays a three-phase network. The controller at any time, the next period current are estimated using a model system. Four switches are used to build a open-delta three-phase inverter, that Four signal switches are necessary for inverter and Signals can be done based on the cost function minimization. Open-Delta Three-phase inverter, produces four pulses required to conduct two basic switching using switching PWM. Appropriate choice of switching states and estimated future states of the phase currents, the inverter may be provided with reasonable accuracy the phase currents. In this study the effect of different parameters such as: inductance coupling inductors, capacitors and reference current is evaluated on the performance of the proposed controller. A sample of inverters, with nominal power 3300 VA is simulated by SIMULINK MATLAB software. At the simulation section of paper, An example of the current predictive controller is designed for Open-Delta three-phase inverter , and is implemented in SIMULINK MATLAB software. The current predictive controller for the six-switch three-phase inverter is designed and implemented in SIMULINK MATLAB software and simulation results have been compared both three-phase inverter topology .

High-Efficiency Current Control Methods Based on Multidimensional Feedback Quantization and Its Application to Three-Phase PMSM

In a six-switch three-phase inverter, the conventional pulsewidth modulation (PWM) has six switching times in every switching period based on the average concept. The used multidimensional feedback quantized modulation (MDFQM) strategy selects one switching state and keeps it in every sampling period based on the minimization of filtered voltage errors between the desired voltage commands and the output voltages. The widths of the output voltage pulse are integer times the fixed sampling time in MDFQM. In this paper, two high-efficiency current control methods based on MDFQM are proposed. They integrate the MDFQM strategy and the current control function to minimize the filtered current errors between the desired current commands and the inverter current. Due to the main advantages of less switching numbers and more closed fundamental current, a high-efficiency performance is achieved. The proposed methods are applied to the current control of a three-phase permanent-magnet synchronous motor. The simulation results and experimental results verify the effectiveness of the proposed methods.

Direct Torque Control of Four Switch Three Phase Inverter fed Induction Motor Sensorless Speed Drive

This paper presents sensorless speed control of induction motor (IM) using four switch three phase inverter (FSTPI) with direct torque and flux control (DTFC). The proposed sensorless DTFC system consists of an adaptive observer of rotor flux to accurately estimate stator resistance and speed simultaneously, without affecting drive performances. The switching technique for DTFC of IM using FSTPI in low power application is based on the principle of similarity between FSTPI and SSTPI (six switch three phase inverter), where the αβ plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean) vectors. This approach allows using the well-known established switching table of SSTPI for FSTPI. The simulation results indicates that the sensorless speed control of FSTPI fed IM with DTFC and adaptive observer provides accurate estimate, good trajectory tracking with different dynamics performance. The experimental results verify the effectiveness of the proposed method at different operating points. DOI: http://dx.doi.org/10.11591/ijpeds.v5i2.5645

Total Harmonic Distortion Analysis of a Four Switch 3-Phase Inverter Fed Speed Sensorless Control of IM Drives

This paper investigates the performance of a Model reference adaptive system (MRAS) based cost-effective drive system of an induction motor (IM) for low-cost applications - high performance industrial drive systems . In this paper, the MRAS is used as a speed estimator and the motor is fed from a four-switch three-phase (FSTP) inverter instead of a conventional six-switch three-phase (SSTP) inverter. This configuration reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms and interface circuits, the proposed control approach reduces the computation for real-time implementation.. The robustness of the proposed MRAS-based FSTP inverter fed IM drive is verified by Experimental results at different operating conditions using digital signal processor (DSP1103) for a 1.1 Kw motor. A performance comparison of the proposed FSTP inverter fed IM drive with a conventional SSTP inverter system is also made in terms of speed response and total harmonic distortion (THD) of the stator current. The proposed FSTP inverter fed IM drive is found quite acceptable considering its performance, cost reduction and other advantages features. DOI: http://dx.doi.org/10.11591/ijpeds.v4i1.5036

Fault Tolerant Of Three-Phase Inverter Fed Speed Sensorless Induction Motor Drive System

This paper proposes an algorithm for fault tolerance of three-phase inverter fed speed sensorless control of three- phase induction motor drive system. The fault tolerance of inverter when one switch is open or one leg of six-switch inverter is lost is considered. The control of the drive system is based on indirect rotor field oriented control theory. Also, the speed estimator is based on model reference adaptive system (using stator current and rotor flux as state variables for estimating the speed). The fault tolerant algorithm is able to adaptively change-over from six switch inverter to four switch inverter topologies when the fault is occurred; also, it makes asmooth transition of the motor speed, torque and current when changing over from faulty condition to new healthy status which is (Four-Switch Three-Phase Inverter (FSTPI) topology), thus, the Six Switch Three-Phase Inverter (SSTPI) topology (pre-fault status) almostly retained. The proposed algorithm is simulated by using the MATLAB/SIMULINK package. The obtained results from the simulation model demonstrate the performance enhancement and good validity of the fault???tolerance control for speed sensorless induction motor drive system

DTC Scheme for a Four-Switch Inverter-Fed Induction Motor Emulating the Six-Switch Inverter Operation

This paper proposes a novel direct torque control (DTC) strategy for induction motor (IM) drives fed by a four-switch three-phase inverter (FSTPI). The introduced strategy is based on the emulation of the operation of the conventional six-switch three-phase inverter (SSTPI). This has been achieved thanks to a suitable combination of the four unbalanced voltage vectors intrinsically generated by the FSTPI, leading to the synthesis of the six balanced voltage vectors of the SSTPI. This approach has been adopted in the design of the vector selection table of the proposed DTC strategy which considers a subdivision of the Clarke plane into six sectors. Simulation results have revealed that, thanks to the proposed DTC strategy, FSTPI-fed IM drives exhibit interesting performance. These have been experimentally validated and compared to the ones yielded by the Takahashi and the basic DTC strategies dedicated to the SSTPI and to the FSTPI, respectively.

Direct torque control of permanent magnet brushless AC drive with single‐phase open‐circuit fault accounting for influence of inverter voltage drop

This study presents a novel direct torque control (DTC) of permanent magnet (PM) brushless AC (BLAC) drive under single-phase open-circuit fault (SOF) accounting for the influences of inverter voltage drop (IVD), together with novel current model-based and voltage model-based stator flux estimation schemes for post-fault operation. It is demonstrated that for accurately elaborating the modified mathematical model, the voltage induced in the stator open phase winding and its relevant flux linkage should be taken into account although they do not contribute to torque production in the post-fault operating mode. It is also proven that reconfiguration of the conventional six-switch three-phase inverter for the purpose of fault-tolerant control results in a significant magnitude imbalance between the α- and β-components of IVD. Thus, the influences of this unbalanced issue on performance of the two proposed stator flux estimation methods are investigated in details and a compensation method for the voltage model-based stator flux estimator is proposed and experimentally verified. It is shown that fault-tolerant control with high performance operation can be maintained for a DTC-based PM BLAC drive under SOF using the proposed modified mathematical model.

Six‐switch inverter emulation based DTC strategy dedicated to three‐switch inverter‐fed induction motor drives

Purpose – The aim of this paper is to propose a novel direct torque control (DTC) strategy for induction motor (IM) drives fed by three‐switch three‐phase inverter (TSTPI). The introduced strategy is based on the emulation of the operation of the conventional six‐switch three‐phase inverter (SSTPI).Design/methodology/approach – The proposed strategy has been achieved thanks to suitable combinations of the six unbalanced voltage vectors intrinsically generated by the TSTPI, leading to the synthesis of the six balanced voltage vectors of the SSTPI. This approach has been adopted in the design of the vector selection table of the proposed DTC strategy which considers a subdivision of the Clarke plane into six sectors.Findings – Simulation results have revealed that, thanks to the proposed DTC strategy, TSTPI fed IM drives exhibit interesting performance.Research limitations/implications – The results obtained by simulation should be validated by experiments.Originality/value – The drawbacks associated with t...