In this study, the performance of fault tolerant single-phase capacitor start capacitor run induction motor powered using seven-level quasi-impedance source inverter (qZSI) is analysed. The seven-level inverter consists of three units of qZSI connected in cascade. When one of the qZSI module fails (due to semiconductor failure), the resultant rms voltage applied to the motor will be reduced by one-third. This leads to reduction in both mechanical speed and electromagnetic torque of the motor. To restore the performance of the motor to pre-fault condition, the voltage deficit must be compensated. In conventional CHB inverter, it is not possible to achieve the pre-fault voltage. However, in qZSI, it is possible to achieve required voltage boost by application of shoot through duty cycle. Here, voltage of other two healthy operating modules can be boosted to reach pre-fault inverter output voltage during post-fault condition. The maximum voltage boost achievable is limited by the maximum shoot-through duty cycle which is related with modulation index. To verify the concept, simulation results of single-phase capacitor-start capacitor-run induction motor with or without proposed control algorithm are discussed. Experimental results for the proposed algorithm with RL load are discussed.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/joe.2018.8042

Fault tolerant single-phase capacitor start capacitor run induction motor powered with cascaded multilevel quasi impedance source inverter

This paper presents a comparative study of the brushless DC and switched reluctance motor drives that are suitable for range hood applications. The objective is to assists engineers in designing new motor drives for home appliances. Summary of principle and optimal design procedure of these motor drives are provided in this paper. Since, home appliances have competitive markets, total cost is playing an important role in their sales. Hence, selecting proper motor drives structures in terms of price and efficient operation is crucial. A comprehensive electromagnetic comparison is discussed to validate motor drives operations. Moreover, a cost comparison is performed to determine a benchmark for engineers to start design and manufacture process.

Design Comparison of BLDC and SR Motor Drives for Range Hood Applications

Variable frequency drive of single-phase induction motor can have many potential advantages, like reduced inrush current during starting, high starting torque, possibility of higher efficiency, more tolerant to variation in grid supply voltage etc Many of the existing electrical gadgets use single-phase induction motor of capacitor start / capacitor-run type A typical example is the motor used in household refrigerators In this application the starting torque requirement is high It will be good if the motor starts with reduced inrush current and if the amount of cooling by refrigerator is controlled by variable speed operation of the motor This work proposes a power electronic circuit which can be incorporated with some change in the existing wiring circuit of the refrigerator

Design and implementation of a variable frequency drive for single-phase induction motor

It is mandatory to keep total harmonic distortion in output of most inverters below a prescribed limit. The harmonic distortions caused due to non-linear loads may not get corrected by simple PID controllers. Repetitive controllers are more effective in such situations. Often repetitive controllers are used as add-on block to the conventional PID controller. Design of repetitive controller can be easily implemented on digital platform. Some controller parameters may have to be decided on trial and error basis.

Application of repetitive control for removal of harmonic distortions from inverter output

In applications where heavy metal welding is performed, the short circuit welding current is very high. During these conditions, manual welding is difficult. Hence, using an automated welding system enhances the productivity and quality of welds, thus reducing dependency on skilled work force. In this manuscript one such mechanism of DC welding, where the welding electrode is automated with a voltage control algorithm is discussed. This algorithm is implemented by sensing the voltage across the electrodes and controls the welding action based on the logic implemented. Implementation of this automated system ensures, monitored time of contact between the job and electrode.

M Naveenkumar

Papers

Design and implementation of a variable frequency drive for single-phase induction motor

Application of repetitive control for removal of harmonic distortions from inverter output

Design and Implementation of Automatic Welding Machine