Abstract : H-bridge cascaded multilevel high-voltage frequency converters have promising technological development prospects. This paper introduces its working principle, theoretically analyzes the converter's operating status under two different operating conditions following a circuit breaker fault, and finally verifies the correctness of the theoretical analysis using SIM software simulation. This provides a basis for implementing corresponding protection measures and offers guidance for the product development of high-voltage frequency converters.
Keywords : H-bridge cascaded high-voltage frequency converter circuit breaking
Analysis of Open Circuit Malfunction for H-Bridge Cascaded Multilevel High Voltage Converter Han Zhiling, Ren Zhaohua, Qian Ming, Hu Peiqing, Zhao Gaoqing, Li Shanqiang, Zhang Jun
Abstract : The H bridge cascaded multilevel high voltage converter is superior to the other high voltage converters. The paper introduces the operating principle of the H bridge cascaded multilevel high voltage con-verter． It is analyzed theoretically how is the circuit working when the circuit is open in two states of work． Finally, the PSIM software is used to emulate． The emulational result validates the analytic result in theory． According to the analytic result we can take some safeguards． So it has guiding significance for studing production 0f H bridge cascaded multilevel high voltage converter．
Keywords : H bridge cascaded high voltage converter open circuit
1 Introduction
With the development of electric drive technology, especially variable frequency speed control technology, high-voltage variable frequency speed control technology, as a large-capacity drive, has been widely used. Currently, the more mature applications in this speed control field include direct AC-DC-AC inverters, indirect AC-DC-AC inverters, and AC-AC inverters. In recent years, multi-level high-voltage inverters have become one of the most popular research topics in medium and high-power motor speed control technology. The basic design idea of multi-level inverters is to superimpose DC voltages (typically capacitor voltages) from different units to form a stepped wave to approximate a sinusoidal output. Currently, the most studied multi-level inverter topologies include: capacitor-floating, diode-clamped, and H-bridge cascaded. Among them, the H-bridge cascaded topology is particularly attractive. Its prototype was proposed by Robicon in the United States and named the perfect harmonic-free inverter. From a performance perspective, because power units are cascaded, there are no dynamic or static voltage equalization problems between components, and the inverter designed with this scheme has a modular structure, facilitating replacement and maintenance. This frequency converter has a good output waveform and does not have problems such as additional heating and torque pulsation of the motor, noise, output du/dt, and common-mode voltage caused by harmonics. It has obvious advantages such as low harmonic pollution to the power grid, high input power factor, and no need to use filters and power factor compensation devices.
For detailed information, please click: Circuit Fault Analysis of H-Bridge Cascaded Multilevel High Voltage Frequency Converter
