scholarly journals Sensorless Current Source-Fed PM Drive System For Low Speed Operations

2021 ◽  
Author(s):  
Ehsan Al-Nabi
Keyword(s):  
Permanent Magnet ◽  
High Power ◽  
Permanent Magnet Synchronous Motor ◽  
Current Source ◽  
Drive System ◽  
Switching Frequency ◽  
Low Speed ◽  
Pulse Width Modulated ◽  
Medium Voltage ◽  
Current Source Converter

In this thesis, a sensorless method for low and zero speed operation is proposed for a high-power medium-voltage pulse-width-modulated Current–Source-Converter (CSC)-fed Interior Permanent Magnet Motor (IPM) drive system. The proposed method is based on injection of a high-frequency (HF) pulsating sinusoidal signal into the estimated synchronous reference frame of the drive’s Field Oriented Control (FOC) scheme. The conventional FOC control scheme, low switching frequency, dc-link inductor and the inverter output three-phase filter capacitor of the medium-voltage high-power current-source drive present some challenges in the generation and design of the HF injection signal. To overcome the challenges, the FOC scheme is modified by introducing a modulation index control with a suitable dc-link current compensation to enhance the dynamic response of the injected signal and prevent any clamp in the injected signal. In addition, a Multisampling Space Vector Modulation (MS-SVM) method is proposed to prevent the distortion in the HF signal due to a low switching frequency to injected signal ratio. It is found that by using the proposed FOC scheme and multisampling modulation scheme, and proper design of the HF signal, an accurate rotor flux angle can be estimated for sensorless zero/low speed operation. Moreover, a novel input power factor compensation method is proposed for a high-power pulse-width-modulated Current-Source-Converter (CSC)-fed Permanent Magnet Synchronous Motor (PMSM) drive system. The proposed method is based on controlling the d-axis stator current component in the field-oriented control scheme of the drive system. The main feature of the proposed scheme is to compensate for the line-side power factor without the need for modulation index control in either the rectifier or the inverter. Simulation and experimental verification for various objectives are provided throughout the thesis. The results validate the proposed solutions for the main challenges of zero/low speed operation of sensorless Current-Source-Converter (CSC)-fed Permanent Magnet Synchronous Motor (PMSM) drive system.

scholarly journals Sensorless Current Source-Fed PM Drive System For Low Speed Operations

2021 ◽  
Author(s):  
Ehsan Al-Nabi
Keyword(s):  
Permanent Magnet ◽  
High Power ◽  
Permanent Magnet Synchronous Motor ◽  
Current Source ◽  
Drive System ◽  
Switching Frequency ◽  
Low Speed ◽  
Pulse Width Modulated ◽  
Medium Voltage ◽  
Current Source Converter

In this thesis, a sensorless method for low and zero speed operation is proposed for a high-power medium-voltage pulse-width-modulated Current–Source-Converter (CSC)-fed Interior Permanent Magnet Motor (IPM) drive system. The proposed method is based on injection of a high-frequency (HF) pulsating sinusoidal signal into the estimated synchronous reference frame of the drive’s Field Oriented Control (FOC) scheme. The conventional FOC control scheme, low switching frequency, dc-link inductor and the inverter output three-phase filter capacitor of the medium-voltage high-power current-source drive present some challenges in the generation and design of the HF injection signal. To overcome the challenges, the FOC scheme is modified by introducing a modulation index control with a suitable dc-link current compensation to enhance the dynamic response of the injected signal and prevent any clamp in the injected signal. In addition, a Multisampling Space Vector Modulation (MS-SVM) method is proposed to prevent the distortion in the HF signal due to a low switching frequency to injected signal ratio. It is found that by using the proposed FOC scheme and multisampling modulation scheme, and proper design of the HF signal, an accurate rotor flux angle can be estimated for sensorless zero/low speed operation. Moreover, a novel input power factor compensation method is proposed for a high-power pulse-width-modulated Current-Source-Converter (CSC)-fed Permanent Magnet Synchronous Motor (PMSM) drive system. The proposed method is based on controlling the d-axis stator current component in the field-oriented control scheme of the drive system. The main feature of the proposed scheme is to compensate for the line-side power factor without the need for modulation index control in either the rectifier or the inverter. Simulation and experimental verification for various objectives are provided throughout the thesis. The results validate the proposed solutions for the main challenges of zero/low speed operation of sensorless Current-Source-Converter (CSC)-fed Permanent Magnet Synchronous Motor (PMSM) drive system.

scholarly journals Model predictive control of high power current-source converter for medium-voltage induction motor drive

2021 ◽  
Author(s):  
Hang Gao
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
High Power ◽  
Current Source ◽  
Dynamic Responses ◽  
Motor Drive ◽  
Switching Frequency ◽  
Medium Voltage ◽  
Pattern Control ◽  
Motor Drive System

As a crucial player in medium-voltage (MV) applications, high power current-source converters (CSCs) feature some distinct advantages in contrast to their voltage-source counterparts. However, the traditional control techniques, based on linear proportional-integral (PI) regulators and low band-width modulation, impose several technical issues during low switching frequency operation. In order to meet more and more stringent performance requirements on industrial drives, various high performance finite control-set model predictive control (FCS-MPC) schemes are proposed in this thesis to control CSCs employed in MV induction motor (IM) drives. The continuous-time and discrete-time dynamic models of high power CSC-fed MV IM drive are deduced, which are used to predict the evolution of state variables in the system. Issues related to MPC approach, such as prediction horizon, weighting factor selection, control delay compensation, accurate extrapolation of references, and nature of variable switching frequency are addressed as well. Model predictive power factor control (MPPFC) is proposed to accurately regulate the line power factor of CSR under various operating conditions. Meanwhile, an active damping function is incorporated into MPPFC to suppress the possible line-side LC resonance. Moreover, an online capacitance estimation method is designed in consideration on the perturbation of the filter parameters of CSR. In order to keep fixed switching frequency of CSC and improve its dynamic responses, model predictive switching pattern control (MPSPC) and model predictive space vector pattern control (MPSVPC) are proposed, in which MPC technique is combined with selective harmonic elimination (SHE) modulation and space vector modulation (SVM), respectively. In steady state, the PWM waveform of CSC follows the pattern of traditional modulation schemes, whereas during transients CSC is governed by MPC approach for the purpose on dynamic performance improvement. A common-mode voltage (CMV) reduced model predictive control (RCMV-MPC) is studied, with which the peak value of CMV in high power CSC-fed MV IM drive can be further reduced in comparison with the traditional RCMV modulation schemes. The dynamic responses of the motor drive system are further improved as well. The simulation on a megawatt motor drive system and experimental results on a low power prototype, validate the effectiveness of the proposed various control schemes.

scholarly journals Simulation and Analysis of Modified DTC of PMSM

2018 ◽  
Vol 8 (5) ◽  
pp. 2894
Author(s):  
D.Kiran Kumar ◽  
G.Tulasi Ram Das
Keyword(s):  
Permanent Magnet ◽  
High Power ◽  
Permanent Magnet Synchronous Motor ◽  
Pi Controller ◽  
Settling Time ◽  
Drive System ◽  
Torque Control ◽  
Phase Current ◽  
Look Up Table ◽  
Drive Systems

This research paper describes the simulation and analysis of the modified DTC for Surface mounted Permanent Magnet Synchronous Motor (SPMSM) using PI controller. Among all of the various drive systems,PMSM is widely used for accurate speed and torque control, with greater efficiency, superior torque to inertia and high power density.The Conventional DTC secheme widely used for this purpose but it is failed to achieve desirable performance of the system for which the modified DTC secheme is propsed.The modified DTC algorithm controls the voltage vectors, directly from a simple look up table depending on outcome of the torque and indirectly flux controllers.The overall drive system can be implemented in SIMULINK/MATLAB environment.The modified DTC is validated with loading conditions.The simulated results are focused on the speed, settling time at loaded conditions, torque and flux linkages ripple and THD in the phase current for modified DTC applied to SPMSM.

scholarly journals Five-level parallel current source converter for high power drives with DC current balance control and superior harmonic performance

2021 ◽  
Author(s):  
Navid Binesh
Keyword(s):  
High Power ◽  
Balance Control ◽  
Dynamic Performance ◽  
Current Source ◽  
Modulation Scheme ◽  
Switching Frequency ◽  
Switching Loss ◽  
Switching Sequence ◽  
Current Source Converter ◽  
Parallel Current

In this thesis, space vector modulation is developed for a 5-level parallel current source converter for high power drives. The modulation scheme is designed to bring superior harmonic performance to the currents on the AC sides. This method synthesizes the rotating reference current vector in the converter's space vector's plane with three adjacent switching vectors. Unbalanced currents of DC links become a practical challenge when two converters are connected in parallel. To balance the DC currents, the proper switching state for every Small and Medium switching vector is chosen from redundant switching states corresponding to the vector based on circuit circumstances and the designed switching sequence. Simulated results verify the effectiveness of the method. In addition, the switching sequence is designed to lower the switching frequency and minimize the switching loss. Finally, the proposed converter and switching scheme are simulated and steady state and dynamic performance are investigated in detail.

Impact of PWM control frequency on efficiency of drive with 1 kW permanent magnet synchronous motor

2018 ◽  
Vol 37 (1) ◽  
pp. 307-318 ◽  
Author(s):  
Tomasz Rudnicki ◽  
Andrzej Sikora ◽  
Robert Czerwinski ◽  
Tadeusz Glinka
Keyword(s):  
Permanent Magnet ◽  
Pulse Width Modulation ◽  
Rotation Speed ◽  
Permanent Magnet Synchronous Motor ◽  
Drive System ◽  
Switching Frequency ◽  
Pwm Control ◽  
Content Type ◽  
Control Frequency ◽  
The Impact

Purpose This paper aims to present the impact of Pulse Width Modulation (PWM) control frequency for specific Permanent Magnet Synchronous Motors (PMSMs) on the efficiency of the entire driving unit. Examinations were carried out for a PMSM unit with a power of 1 kW, rated speed of 1,000 rpm, and rated torque of 6 Nm. Design/methodology/approach The PWM frequency ranged from 4 to 20 kHz with increments of 1 kHz. Measurements were taken for each of the foregoing frequencies, for the different load torques, and for the different rotation speeds including overspeed. The results achieved allow the PWM control frequency to be properly adjusted for each PMSM to operate the entire driving unit in the most efficient way and, in consequence, save energy consumed by the drive. Findings Obtained results may be used as a kind of background for the design of drive system. Research limitations/implications For a specific PMSM-based drive system, one can find the optimal PWM control frequency. This frequency depends on the rotation speed and torque of the motor. However, the validity of the results presented in the paper is limited. They are valid for the specific motor drive under test and cannot be generalized easily. Originality/value This work shows that there is some maximal efficiency of the entire system depending on the rotation speed, load torque and switching frequency of the power transistors. For a specific motor working in a certain condition, we can find the minimum power loss.

scholarly journals Model predictive control of high power current-source converter for medium-voltage induction motor drive

2021 ◽  
Author(s):  
Hang Gao
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
High Power ◽  
Current Source ◽  
Dynamic Responses ◽  
Motor Drive ◽  
Switching Frequency ◽  
Medium Voltage ◽  
Pattern Control ◽  
Motor Drive System

As a crucial player in medium-voltage (MV) applications, high power current-source converters (CSCs) feature some distinct advantages in contrast to their voltage-source counterparts. However, the traditional control techniques, based on linear proportional-integral (PI) regulators and low band-width modulation, impose several technical issues during low switching frequency operation. In order to meet more and more stringent performance requirements on industrial drives, various high performance finite control-set model predictive control (FCS-MPC) schemes are proposed in this thesis to control CSCs employed in MV induction motor (IM) drives. The continuous-time and discrete-time dynamic models of high power CSC-fed MV IM drive are deduced, which are used to predict the evolution of state variables in the system. Issues related to MPC approach, such as prediction horizon, weighting factor selection, control delay compensation, accurate extrapolation of references, and nature of variable switching frequency are addressed as well. Model predictive power factor control (MPPFC) is proposed to accurately regulate the line power factor of CSR under various operating conditions. Meanwhile, an active damping function is incorporated into MPPFC to suppress the possible line-side LC resonance. Moreover, an online capacitance estimation method is designed in consideration on the perturbation of the filter parameters of CSR. In order to keep fixed switching frequency of CSC and improve its dynamic responses, model predictive switching pattern control (MPSPC) and model predictive space vector pattern control (MPSVPC) are proposed, in which MPC technique is combined with selective harmonic elimination (SHE) modulation and space vector modulation (SVM), respectively. In steady state, the PWM waveform of CSC follows the pattern of traditional modulation schemes, whereas during transients CSC is governed by MPC approach for the purpose on dynamic performance improvement. A common-mode voltage (CMV) reduced model predictive control (RCMV-MPC) is studied, with which the peak value of CMV in high power CSC-fed MV IM drive can be further reduced in comparison with the traditional RCMV modulation schemes. The dynamic responses of the motor drive system are further improved as well. The simulation on a megawatt motor drive system and experimental results on a low power prototype, validate the effectiveness of the proposed various control schemes.

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