Three-phase inverter with a variable control algorithm

2021 ◽  
Vol 14 (3) ◽  
pp. 1-11
Author(s):  
Grzegorz Szerszeń ◽  
Damian Zygadło
Keyword(s):  
Frequency Control ◽  
Frequency Converter ◽  
Operation Mode ◽  
Control Algorithms ◽  
Phase Inverter ◽  
Hardware System ◽  
Smooth Change ◽  
Three Phase ◽  
Control Step ◽  
Three Phase Inverter

The paper presents the construction of a three-phase frequency converter with the possibility of choosing the type of PWM modulation and a smooth change of the frequency of the modulated signal. In a practical way, various inverter control algorithms were implemented in the same hardware system using the STM ARM Cortex M3 processor. The use of THIPWM modulation allowed to reduce the harmonic content in the output signal and effectively use the possibilities of the power source. The system can choose one of two scalar control algorithms, with the option of compensation for the influence of the stator resistance on the motor shaft torque in the initial range of the linear control characteristic at a constant voltage to frequency ratio. The research confirmed that the most advantageous type of PWM in this system is unipolar double-edge modulation. The use of the THIPWM method resulted in a gain in the amplitude of the fundamental harmonic of the output voltage for the three-phase inverter operation mode compared to the SPWM method. The appropriate precision of the frequency control step was also obtained, and the test results confirmed the functionality of the converter.

scholarly journals Development of a control algorithm for the three-phase inverter of the two-phase electric drive for reducing the number of switching elements

Vestnik IGEU ◽  
2019 ◽  
pp. 49-61 ◽  
Author(s):  
V.N. Meshcheryakov ◽  
A.S. Belousov
Keyword(s):  
Electric Drive ◽  
Frequency Converter ◽  
Current Control ◽  
Two Phase ◽  
Phase Inverter ◽  
Electric Drives ◽  
Electric Drive System ◽  
Three Phase ◽  
Three Phase Inverter ◽  
Starting Torque

High overload capacity and ability to control speed in a wide range are important requirements for modern electric drives. Introduction of a low-power adjustable two-phase electric drive with these properties into me-chanical devices is limited by the frequency converter function to convert a three-phase network into a two-phase one when the unit power of such mechanisms increases. Previous studies have shown that it is possible to use a standard frequency converter with a three-phase bridge voltage inverter applying a new control algorithm based on space-vector PWM. When PWM is used, the switching frequency of the key inverter elements remains quite high, strictly specified, non-amenable to reduction without degrading the harmonic composition. The goal of this work is to develop an algorithm for two-phase electric drive control that would reduce the number of switching operations of the switch elements of a three-phase inverter with-out increasing the deviations of the instantaneous values of the phase currents from the reference sine curve. The study employed provisions of the theory of automatic control, the theory of electric drive and methods of mathematical modeling. The simulation object was the control system of a two-phase motor; the elements of the Matlab Simulink software package were used. An algorithm has been proposed for operating a three-phase inverter of a two-phase electric drive system. The difference of the algorithm from the well-known control system of a standard bridge inverter with space vector PWM consists in using phase current control relays and dividing the period of sinusoidal phase currents into four sections ensuring a decrease in the number of switching operations of the inverter switch elements when the maximum instantaneous deviations of current values from a sinusoidal reference are equal, the starting torque of the motor is stabilized and the speed control is smooth. The results show that with an equal maximum deviation of the instantaneous current values from a given sinusoidal value, the number of switching operations of the inverter switch elements in the proposed system is smaller than in the known analogues. The electric drive system ensures the start of a two-phase motor with stabilization of the starting torque under increased load. The considered system of variable frequency control with current control relays can be used for two-phase electric drives of mechanical devices and household electric appliances and is promising as a substitute for less cost-effective single-phase and capacitor motors.

scholarly journals Modified Topology for Three-Phase Multilevel Inverters Based on a Developed H-Bridge Inverter

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1848
Author(s):  
Samuel Nii Tackie ◽  
Ebrahim Babaei
Keyword(s):  
Control Method ◽  
Frequency Control ◽  
Control Technique ◽  
Dynamic Voltage Restorer ◽  
Phase Inverter ◽  
Semiconductor Switches ◽  
Three Phase ◽  
Power Switches ◽  
Dynamic Voltage ◽  
Three Phase Inverter

This paper proposes a modified three-phase inverter from the developed H-bridge structure having multilevel functionality. The proposed topology can generate 7-levels of phase voltages and 13-levels of line voltages. Simple control methods such as fundamental frequency control method can be applied to the proposed topology. By adding three single-phase transformers, galvanic isolation is created for use in three-phase Dynamic Voltage Restorer systems. The proposed three-phase inverter utilizes less number of components; dc sources, semiconductor switches and driver circuits. Lower rated power switches with reduced blocking voltages are also used. These attributes make the proposed topology less complex in-terms of architecture and control. Comprehensive analysis of the proposed three-phase multilevel inverter and other presented topologies are investigated with respect to levels of output voltage, driver circuit quantity, dc voltage count, total component quantity and standing voltage. Details of the appropriate control technique employed is explained. Finally, practicability of the proposed inverter is validated by simulation using EMTDC/PSCAD software and experimental prototype.

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