Reduction of total harmonic distortion in power inverters

The output voltage of PWM power inverters shows harmonic distortion due to several causes; the main ones are the modulation algorithm, nonlinearities in the output filter, dead times, voltage drops across the switches and modulation of the dc bus voltage. The distortion is more evident when using lo...

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Detalles Bibliográficos
Autores: Oliva, Alejandro Raul, Chiacchiarini, Hector Gerardo, Aymonino, Oscar Andres, Mandolesi, Pablo Sergio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/105850
Acceso en línea:http://hdl.handle.net/11336/105850
Access Level:acceso abierto
Palabra clave:Power inverter
Distortion
Blanking time
THD
https://purl.org/becyt/ford/2.2
https://purl.org/becyt/ford/2
Descripción
Sumario:The output voltage of PWM power inverters shows harmonic distortion due to several causes; the main ones are the modulation algorithm, nonlinearities in the output filter, dead times, voltage drops across the switches and modulation of the dc bus voltage. The distortion is more evident when using low dc bus voltages. As a result, motors driven by these inverters have important torque pulsations. This work proposes to reduce the distortion produced by dead times and voltage drops across the switches using a simple algorithm that recalculates the width of each PWM pulse, while preserving the ideal area. By simulation, the THD was reduced from 18% to 0.29% in a single-phase inverter. The proposed algorithm only needs products and sums, so it is suitable for being implemented on a DSP with a very low processing load.