Design and Analysis of a 54-Pulse Converter and 7-Level Hybrid Inverter for Medium Voltage Induction Motor Drive

This paper exhibits reduced components based on hybrid configurations {symmetric (
Type-I, Type-II
) of a multilevel inverter utilized to feed power to a multi pulse converterbased induction motor drive. Detailed designed concepts, development and operation {through: simulation (for IM: 932.5kW/ 4.16kV) and experimentation (for IM: 7.5kW/415V)} of presented converter are explained by utilizing hybrid symmetric (Type-I) seven-level inverter along with 54-pulse AC-DC converter fed medium voltage drive. A 54-pulse converter is connected at the grid side of this system, which enhances power quality at the grid side and supplies power through nine DC-links, those are input terminals of Type–I hybrid inverter. Type-I&II power multi-level converters offer a reduced switch count configuration with simplest cascaded structure to maintain reliability of drive compared to existing reduced switch inverters configuration. Apart from this, a switching frequency optimal- nearest level control (SFO-NLC) is utilized to generate a low switching frequency gating signals to presented 7-level inverter switches, where it is useful to enhance the efficiency of the inverter because this technique is capitalized on advantages of both SFO and NLC. Hence, it describes key design concepts, development, and control of converters to meet medium-voltage drive challenge such as high-power quality, low switching loss and compact size. Simulated and test results ensure practicality of these converters for the drive adhering to the IEEE519 standard. Presented new power converters configuration performs a highquality power conversion at both sides of the drive without any additional filter at any side or high switching operation at drive side converter.