No abstract

Genetic algorithms(GA) is optimization technique used in the equivalent load test of the induction motors to select the values of the factors(modulation indicators) that effect on the performance properties in terms of the values of the currents and the total loss within the machine. One way to choose these parameters is by trial and error while this paper based on GA method to improve the parameters selection. A model is designed to simulate the loading of the induction motor and obtain its own results by the MATLAB program 2017a. There are different methods used to achieve this task such as PWM inverter with different modulation techniques, Constant Voltage Variable Frequency (CVVF) method, Variable Voltage Constant Frequency (VVCF) method and Variable Voltage Variable Frequency (VVVF) method.

<p><span lang="EN-US">Boost converters are employed in DC motors, switch-mode power supplies, and other applications. Practical implementation difficulties, reliance on variable-frequency units, and delayed dynamic responses to changes in load and voltage are the main drawbacks of different control methods for the boost converter. In this paper, two techniques were proposed with the target of controlling the boost converter to improve the efficiency of the converter's performance. The two techniques used in this paper depended on fixed-frequency mode instead of variable-frequency mode because of the demerits of the latter factor. The first technique is the sliding-mode control for the AC-DC converter to achieve power factor correction and reduce the harmonic ratio significantly while regulating the output voltage. This technique was used for the DC-DC converter to obtain a rapid dynamic response to control sudden or considerable changes in loads or input voltages with a regulated output voltage. Moreover, the two-loop cascade control is the second proposed technique for the DC-DC converter to achieve an excellent dynamic response under step loads or input voltage variations with an excellently regulated output voltage. Re-simulation results validated the proposed design approach and illustrated the proposed controller's robustness and faster response time.</span></p>

The AC line input voltage is frequently rectified by single-phase diode rectifiers and filtered using sizable electrolytic capacitors. The capacitor draws current in brief pulses, so harmonics distort the line current, resulting in high losses. Harmonics and line current distortions harm the unity power factor and efficiency. This article adopts a simple single-stage AC-DC converter with a high-power factor and low total harmonic distortion. The PI hysteresis current control was utilized to reduce the total harmonic distortion and increase the power factor at full load. The PI controller was added to the outer voltage loop to regulate the output voltage. Ziegler-Nichol's tuning method was used to determine the controller gain levels. Simulation results were obtained for the AC-DC converter at a constant switching frequency to show the benefits of the proposed control method, which has a low total harmonic distortion and a high-power factor compared with cases without a controller. The proposed control method is accurate and efficient for achieving the power factor correction converter. Besides, the proposed control was stable during dynamic and steady-state responses.