Novel Three-Phase Nine-Level Inverter and Its Control Strategies

Abstract

In this paper, the authors propose a new three-phase, nine-level inverter with self-balancing of capacitor voltages. The proposed inverter is the result of a serial connection of the SPUC topology and the NPC converter. A single DC source is used, and each phase is made up of nine power switches and three capacitors. Two control techniques are proposed to maintain the voltage of the capacitors to the desired values, the first of which is a PWM technique that ensures the self-balancing of capacitor voltages in open loops without using any filters or PI regulators, and the second is based on the hysteresis control which offers a nearly sinusoidal waveform of the load current without using any voltage sensors. The authors make use of the Matlab Simulink environment to perform the simulation of the proposed concept. The dynamics of the latter was verified against load change.

Extension of Operating Range in Hybrid Cascaded H-Bridge Inverters with Capacitor Voltage Balancing Capability

“…Figure 7 shows the control block diagram of split DC-link and flying capacitor voltages. With this generalized control scheme, all capacitor voltages are regulated at the corresponding references, and thus keep the voltage THD low, particularly at HCHB inverters with a higher number of levels [63][64][65][66].…”

A Nine-Level Inverter with Adjustable Turn-Off Time for Helicopter Transient Electromagnetic Detection

“…The current pulse inverter should meet engineering indicators such as high power and fast turn-OFF time. The high power will provide the system with a more profound detection distance, and the faster turn-OFF time will provide the system with a better detection effect [ 14 , 15 , 16 , 17 , 18 , 19 ].…”