Comparative study of control techniques for three phase PWM rectifier

This paper studies and compare the performances of different control strategies of 3-phase active rectifier under different load and frequency conditions. There are three main control approaches to be investigated such as: Voltage Oriented Control (VOC), Direct Power Control (DPC) and Model Predictive Control (MPC). The traditional method VOC has been used widely in practice. Its control principle is available to many different grid-connected converter systems such as electric drive system, renewable energy conversion system. However, the problem of optimal design of the current regulators for the different operating conditions of the system is not an easy problem. The DPC and MPC methods then help to eliminate the disadvantages of the VOC. The MPC method has been now become much interesting since it offers a general solution to a multi-goal optimization problem. In the paper, the system structures and controller parameters are briefly presented. The main evaluation factors of the active rectifier are low input current distortion (THD), a unit input power factor and stable DC output voltage. Three methods are analyzed and verified using MATLAB software and measuring experiment on a real model. The obtained results show that the VOC method achieves stable quality under different load as well as the switching frequency conditions, while the MPC method may achieve good quality with a rather high switching frequency.

Download Full-text

Feedback Loop Control Strategies of the Multi Dc Bus Link Voltages Using Adaptive Fuzzy Logic Control

Journal of Electrical Engineering ◽

10.2478/jee-2013-0021 ◽

2013 ◽

Vol 64 (3) ◽

pp. 143-151

Author(s):

Farid Bouchafaa ◽

Mohamed Seghir Boucherit ◽

El Madjid Berkouk

Keyword(s):

Fuzzy Logic ◽

Fuzzy Logic Controller ◽

Control Strategies ◽

Harmonic Distortion ◽

Power Converter ◽

Voltage Source ◽

Switching Frequency ◽

Pwm Rectifier ◽

Loop Control ◽

Multilevel Inverters

Voltage source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes that have led to the development of the studies about multilevel inverters are the generation of output voltage signals with low harmonic distortion; the reduction of switching frequency. A serious constraint in a multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of five-level neutral point clamping (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In order to stabilize these DC voltages, we propose in this paper to study the cascade constituted by three phases five-level PWM rectifier, a clamping bridge and five-level NPC (VSI). In the first part, we present a topology of five-level NPC VSI, and then they propose a model of this converter and an optimal PWM strategy to control it using four bipolar carriers. Then in the second part, we study a five-level PWM rectifier, which is controlled by a multiband hysteresis strategy. In the last part of this paper, the authors study shows particularly the problem of the stability of the multi DC voltages of the inverter and its consequence on the performances of the induction motors (IM). Then, we propose a solution to the problem by employed closed loop regulation using PI regulator type fuzzy logic controller (FLC). The results obtained with this solution confirm the good performances of the proposed solution, and promise to use the inverter in high voltage and great power applications as electrical traction.

Download Full-text

Evaluation of Low Cost, High Temperature Die and Substrate Attach Materials for Silicon Carbide (SiC) Power Modules

International Symposium on Microelectronics ◽

10.4071/2380-4505-2018.1.000317 ◽

2018 ◽

Vol 2018 (1) ◽

pp. 000317-000325

Author(s):

Sayan Seal ◽

Brandon Passmore ◽

Brice McPherson

Keyword(s):

High Temperature ◽

Room Temperature ◽

Operating Conditions ◽

Acoustic Microscopy ◽

Switching Frequency ◽

Power Devices ◽

Formidable Challenge ◽

Die Attach ◽

Power Modules ◽

High Switching Frequency

Abstract The performance of SiC power devices has demonstrated superior characteristics as compared to conventional Silicon (Si) devices. Some of the advantages of SiC power devices over Si include higher voltage blocking capability, low specific on-resistance, high switching frequency, high temperature operation, and high power density. Thus, SiC modules are capable of processing significant levels of power within much smaller volumes compared with its Si counterparts. These high thermal loads present a formidable challenge in integrating SiC devices in power modules. For example, known-good materials and processes for silicon power modules are not rated at the aggressive operating conditions associated with SiC devices. Two of the most critical interfaces in a power electronics module are the die-attach and substrate- attach. A degradation in these interfaces often results in potentially catastrophic electrical and thermal failure. Therefore, it is very important to thoroughly evaluate die-attach materials before implementing them in SiC power modules. This paper presents the methodology for the evaluation of die attach materials for SiC power modules. Preforms of a lead-free high-temperature attach material were used to perform a die and substrate attach process on a conventional power module platform. The initial attach quality was inspected using non- destructive methods consisting of acoustic microscopy and x-ray scanning. Die attach and substrate attach voiding of < 5% was obtained indicating a very good attach quality. Cross-sectioning techniques were used to validate the inspection methods. The initial attach strength was measured using pull tests and shear tests. The measurements were repeated at the rated temperature of the module to ensure that the properties did not degrade excessively at the service temperature. At the rated module temperature of 175 °C, the die bonding strength was found to be ~ 75 kg. This was only 25% lower than the strength at room temperature. In addition, the contact pull strength was measured to be > 90 kg at 175 °C, which was 25% lower than the value measured at room temperature. The effect of power cycling and thermal cycling on the quality and strength of the die and substrate attach layers was also investigated.

Download Full-text

Solar PV fed non-isolated DC-DC converter for BLDC motor drive with speed control

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v13.i1.pp313-323 ◽

2019 ◽

Vol 13 (1) ◽

pp. 313

Author(s):

G. G RajaSekhar ◽

Basavaraja Banakar

Keyword(s):

Control Method ◽

Speed Control ◽

Current Control ◽

Operating Conditions ◽

Switching Frequency ◽

Bldc Motor ◽

Solar Pv ◽

Pv System ◽

High Switching Frequency ◽

Interleaved Boost Converter

Brushless DC motors (BLDC) are predominantly used these days due to its meritorious advantages over conventional motors. The paper presents PV fed BLDC speeds control system. A closed-loop interleaved boost converter increases the voltage from PV system to required level. Converter for BLDC operates at fundamental switching frequency which reduces losses due to high switching frequency. Internal current control method is developed and employed for the speed control of PV fed BLDC motor by sensing the actual speed feedback. Internal current controlled PV fed BLDC drive is analyzed with increamental speed with fixed torque and decreamental speed with fixed torque operating conditions. Also the system with speed control is verified for variable torque condition. The system is developed and results are developed using MATLAB/SIMULINK software.

Download Full-text

Analysis of Symmetric Dual Switch Converter under High Switching Frequency Conditions

Electronics ◽

10.3390/electronics9122183 ◽

2020 ◽

Vol 9 (12) ◽

pp. 2183

Author(s):

Yu Tang ◽

Dekai Kong ◽

Haisheng Tong

Keyword(s):

High Frequency ◽

Low Voltage ◽

Low Frequency ◽

High Gain ◽

Operating Conditions ◽

Switching Frequency ◽

Operating Characteristics ◽

Frequency Condition ◽

High Switching Frequency ◽

Parasitic Parameters

Electric vehicle batteries have the problem of low output voltage, so the application of a high-gain converter is a research hotspot. The symmetrical dual-switch high gain converter has the merits of simple structure, low voltage and current stress, and low EMI. Due to the deterioration of circuit performance caused by circuit parasitic parameters under high frequency operating conditions, the former analysis under low frequency condition cannot satisfy the requirements for performance evaluation. To clarify whether the symmetrical dual-switch high-gain converter can maintain its operating characteristics under high-frequency operating conditions, this paper establishes the converter model considering parasitic parameters, and deduces the sneak circuit modes at high frequency. The effects of parasitic parameters at high frequency on voltage gain, switch stress, and symmetrical operating are analyzed, which is beneficial for the selection and optimization of power devices. This paper believes that considering parasitic parameters may reduce the output gain of the symmetrical double-switch high-gain converter considering parasitic parameters under high frequency conditions, increase the switching stress, and affect the symmetry of the circuit operation when the parasitic parameter values are different. Finally, an experimental platform rated on 200 W with 200 kHz switching frequency is established, and experimental verification is given to verify the analysis.

Download Full-text