Modular Multilevel Converter Control Strategy with Fault Tolerance

Abstract

Abstract. The Modular Multilevel Converter (MMC)technology has recently emerged in VSC-HVDC applications where it demonstrated higher efficiency and fault tolerance compared to the classical 2-level topology. Due to the ability of MMC to connect to HV levels, MMC can be also used in transformerless STATCOM and large wind turbines. In this paper, a control and communication strategy have been developed to accommodate tolerant module failure and capacitor voltage unbalance. A downscaled prototype converter has been built in order to validate and investigate the control strategy, and also test the proposed communication infrastructure based on Industrial Ethernet.

Model-Based Latency Compensation for Network Controlled Modular Multilevel Converters

“…where matrices andB correspond to the plant model and can be obtained by the digitalization of Equations (3) or (4). If we substitute (12) in (8), the plant input vector is expressed by…”

“…Hillers, Tu and Biela [10] discussed the implications of the control structure for the system reliability when using a communication network. Researchers from Aalborg University implemented a partly distributed control in an MMC prototype to reduce the data shared globally and demonstrated single fault tolerance when using EtherCAT [11][12][13][14]. Reducing the amount of data sent through the communication link has also been the core idea in [15,16].…”

Three-phase Photovoltaic Systems: Structures, Topologies, and Control

“…Another advantage of such a topology is the possibility to use LV power switches. By adding redundant cells on each phase of the converter, fault-tolerant operation can be ensured [35]. By paralleling inverters, a flat efficiency profile can be achieved over a wide range of power, where the number of parallel connected inverters depends on the available power from the solar panels [36].…”

Performance comparison of phase shifted PWM and sorting method for modular multilevel converters

“…Due to their low switching frequency leads to high efficiency and the high number of output voltage levels requires a minimal grid side filter. Another advantage is that the large number of modules present in the topology ensures fault tolerant operation [1]. In Fig.…”