This paper deals with the minimization of the harmonic distortion to improve the power quality by using 9 steps multilevel power converter, using genetic algorithms to optimized a multi-PWM modulation, and minimizing Total Harmonic Distortion (THD) to almost zero. A novel numerical technique is develop as the optimization approach to obtain a math expression that quantifies the THD in the 9 steps multilevel PWM waveform, in terms of the firing angles and the position of the levels in the first quarter-wave modulation. A prototype was development for experimental verification.

This paper deals with the development of a V/F control of an induction motor with THD optimization using cascaded multilevel converters. The optimization algorithm was a genetic algorithm, which allows to obtain a voltage vs. frequency ratio (V/F) that decreases the voltage value as the frequency is reduced by maintaining the total harmonic distortion (THD) at levels very close to 0% over the entire frequency range of operation. The power converter is a common-source cascaded H-bridge multilevel inverter with maximum 15 steps per line voltage. The inverter was simulated by supplying a three-phase induction motor. The result of the simulations allows verify the optimization of the THD throughout all of the frequency operation range.

This paper describes the design and develop of a common source three-phase multilevel power converter, with five levels in the phase voltage and nine levels in the line voltages. The modulation is optimized using genetic algorithms that perform a selective harmonics elimination of the first 20 components to improve power quality. To validate, an induction motor fed by the optimized multilevel power inverter was used, where improvements were shown in the waveforms of the line currents and a significant improvement of the power quality is achieved.

This paper presents a comparative analysis of the H-bridge multilevel cascaded converters with common source and with independent source, and both with selective harmonic elimination (SHE). Two prototypes of nine levels of output voltage are implemented, which use a standard step modulation and optimized PWM modulation (using genetic algorithms). The non load and the load test determine the total harmonic distortion (THD) differences and the behavior of the RMS values. Finally, the converter output waveforms and performance are discussed, also the behavior of the DC buses and the cost of both prototypes.

Introduction− The controlled PID is the most widely used mathematical algorithm as a regulatory control strategy in industrial environments. The applications are varied; however, its answer depends on the proper calculation of its three parameters: the proportional, the derivative, and the integral. Analytical tuning and experimental methods solve the problem, but new tuning possibilities are now enabled within the digital and process integration context. Objective− Automatically and remotely obtain the optimal parameters of the PID controller, taking advantage of an online connection via the OPC communication protocol to analyze the transient response of the system. Methodology− The study is carried out in three main phases; it begins with a PD3 SMAR thermal process with connection via OPC; in this phase, the mathematical model of the process is built analytically based on fundamental laws. In the second phase, using an analytical tuning method, the PID control architecture is created on which the online experimentation is carried out. In the third phase, the genetic algorithms for automatic tuning are implemented, extracting performance measures from the PID controller through the transient response of the process and optimally determining the values for the proportional, derivative, and integral parameters. Results− The automatic tuning method was tested with two properly instrumented industrial processes. The potential for application can be seen due to its good result and because it does not require specific mathematical knowledge compared to conventional tuning methods. Conclusions− The automatic tuning method can be used remotely to calculate the optimal parameters of a PID controller. The parameters are calculated from the transient response and the definition of design criteria adaptable to any need for control, response, and process.