Control and operation of the MMC‐based drive with reduced capacitor voltage fluctuations

Bolaños, Mauricio Antonio Espinoza; Díaz, Matías; Donoso, Felipe; Letelier, Arturo; Cárdenas, Roberto

doi:10.1049/joe.2018.8080

Cited by 3 publications

(3 citation statements)

References 21 publications

(40 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, the voltage fluctuations are allowed to operate within an acceptable margin around the DC voltage of the capacitor. Recently, the DC port voltage E (see Figure 1) has been manipulated to maintain the amplitude of the voltage fluctuations in the capacitors [11][12][13][14][15]. In this case, the gridside converter is an active rectifier [11,12,16,17] or an MMC composed of half-bridge and full-bridge cells [18,19].…”

Section: Introductionmentioning

confidence: 99%

“…In this case, the gridside converter is an active rectifier [11,12,16,17] or an MMC composed of half-bridge and full-bridge cells [18,19]. However, most of the proposals add full-bridge modules to the machine-side MMC [14,15] or reduce E to values close to zero during machine start-up, limiting the dynamic response of the converter [11][12][13]. Additionally, in all these studies, the DC port voltage is defined using feed-forward signals.…”

Section: Introductionmentioning

confidence: 99%

“…Variable DC port voltage: the DC port voltage E is used to maintain the amplitude of the fluctuations in the cluster voltages. However, the machine-side MMC has more components [14,15] and its dynamic regulation is poor [11][12][13]. See Figure 2c.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The Closed-Loop Control of the Half-Bridge-Based MMC Drive with Variable DC-Link Voltage

et al. 2023

View full text Add to dashboard Cite

The modular multilevel converter (MMC) based on half-bridge modules is a power converter topology suitable for high-power medium-voltage variable-speed drives. However, the voltage of its flying capacitors is negatively affected when low frequencies appear at the AC port. This paper analyzes the influence of using a variable DC port voltage in a machine-side MMC by implementing a closed-loop approach, ensuring a constant voltage fluctuation in the capacitors of the MMC during the whole operating range. The effectiveness of the proposed control scheme is demonstrated through simulation studies and experimental validation tests conducted using a 7.5 kW experimental prototype composed of an induction machine fed by an MMC with 18 half-bridge cells.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Closed-Loop Control of the Half-Bridge-Based MMC Drive with Variable DC-Link Voltage

et al. 2023

View full text Add to dashboard Cite

show abstract

A Control Strategy for Suppressing Submodule Capacitor Voltage Fluctuation of MMC Based on Circulating Current Voltage Drop Balance

Yang

Zhang

et al. 2021

IEEE Access

View full text Add to dashboard Cite

Experimental Validation of a Nested Control System to Balance the Cell Capacitor Voltages in Hybrid MMCs

et al. 2021

View full text Add to dashboard Cite

In a hybrid modular multilevel converter (MMC), capacitor voltage balance between the Full-Bridge Sub-Modules (FBSMs) and Half-Bridge Sub-Modules (HBSMs) is only possible when the arm currents are bipolar. For a grid-connected MMC, operating at unity power factor, this is typically achievable when the modulation index is less than 2. Previous control methodologies, based on open-loop feed-forward compensating currents, have been proposed to operate an MMC with a higher modulation index. However, these solutions do not minimize the compensating currents; they cannot compensate entirely for both the variations in the operating conditions and the parameters typically encountered in a real implementation; and they do not consider the actual capacitor voltage imbalance between the FBSM and HBSMs. In this paper, a new nested closed-loop control algorithm based on an outer voltage control loop with an inner current loop is proposed and experimentally validated. Feed-forward currents are still utilised in the inner loop, but they are calculated using a new optimising algorithm which minimises the required compensating currents. Moreover, to the best of our knowledge, this is the first work where explicit algebraic equations to calculate these compensating currents are provided. Experimental results to validate the approach, obtained with an 18-cell hybrid MMC, are presented and discussed in the paper.

show abstract

Control and operation of the MMC‐based drive with reduced capacitor voltage fluctuations

Cited by 3 publications

References 21 publications

The Closed-Loop Control of the Half-Bridge-Based MMC Drive with Variable DC-Link Voltage

The Closed-Loop Control of the Half-Bridge-Based MMC Drive with Variable DC-Link Voltage

A Control Strategy for Suppressing Submodule Capacitor Voltage Fluctuation of MMC Based on Circulating Current Voltage Drop Balance

Experimental Validation of a Nested Control System to Balance the Cell Capacitor Voltages in Hybrid MMCs

Contact Info

Product

Resources

About