Fully decoupled current control and energy balancing of the Modular Multilevel Matrix Converter

Abstract

Abstract-The Modular Multilevel Matrix Converter (M3C) is a Modular Multilevel Converter topology which is suitable for high power low speed drive applications. This paper presents a fully decoupled current control which allows an independent input, output and internal balancing current control. To equalize the energy stored in the nine converter arms, an energy and balancing control is presented which includes average, horizontal, vertical and diagonal balancing control loops. Simulation results are used to verify the function of the M3C together with an induction motor drive system. Additionally, the proper function of the recently constructed arm PCB working as single phase multilevel STATCOM is presented. This PCB will be used for each arm in the laboratory prototype of the M3C in the near future.

The application of the modular multilevel matrix converter in high-power wind turbines

“…In recent publications, a modelling of the M3C have been reported (see [11], [12]). In these papers, the basic approach is to use a so-called double-0 transformation.…”

“…Then, (2) is pre-multiplied by and post-multiplied by yielding: According to [12], [11], the transformation presented above represents a decoupled model of the M3C, which enables the full use of the transformed branch currents as degrees of freedom. Using the electric circuit approach proposed in [13], the M3C equivalent circuit is presented in Fig.…”

“…5. To operate the wind turbine at the MPPT, the generator electrical torque is calculated as is presented in equation (7), and the reference frame control system regulates the quadrature current following the reference obtained in equation (12). Where ̅ represents the capacitor average voltage in one branch -assuming that all capacitors are regulated at the same set point-.…”

Modelling and control of the Modular Multilevel Matrix Converter and its application to Wind Energy Conversion Systems

“…Modellings of the M3C have been recently reported in [7], [8], where the fundamental approach is to use a so-called double 0 Transformation. The approach exposed in this paper, is based on [8], but attempts to be an alternative more intuitive.…”

Control scheme of hexagonal modular multilevel direct converter for offshore wind power integration via fractional frequency transmission system

“…It replaces the half-bridge cells of the branch submodules (SMs) in a modular multilevel converter (MMC) with full-bridge cells and can directly connect two three-phase AC systems of different frequencies and voltage amplitudes without a central DC-link. Fundamental research on the M 3 C has been conducted based on modeling and experimentation [10][11][12][13][14]. The M 3 C retains the advantages of easy scalability and high power quality that the MMC has due to its modular design.…”