An innovative modular multilevel converter topology suitable for a wide power range
23 Jun 2003-Vol. 3, pp 272-277
TL;DR: In this article, a new multilevel converter topology suitable for very high voltage applications, especially network interties in power generation and transmission, is presented, and a suitable structure of the converter-control is proposed.
Abstract: This paper presents a new multilevel converter topology suitable for very high voltage applications, especially network interties in power generation and transmission. The fundamental concept and the applied control scheme is introduced. Simulation results of a 36 MW-network intertie illustrate the efficient operating characteristics. A suitable structure of the converter-control is proposed.
Citations
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TL;DR: An overview of the recent advances in the area of voltage-source converter (VSC) HVdc technology is provided in this paper, where a list of VSC-based HVDC installations worldwide is included.
Abstract: The ever increasing progress of high-voltage high-power fully controlled semiconductor technology continues to have a significant impact on the development of advanced power electronic apparatus used to support optimized operations and efficient management of electrical grids, which, in many cases, are fully or partially deregulated networks. Developments advance both the HVDC power transmission and the flexible ac transmission system technologies. In this paper, an overview of the recent advances in the area of voltage-source converter (VSC) HVdc technology is provided. Selected key multilevel converter topologies are presented. Control and modeling methods are discussed. A list of VSC-based HVdc installations worldwide is included. It is confirmed that the continuous development of power electronics presents cost-effective opportunities for the utilities to exploit, and HVdc remains a key technology. In particular, VSC-HVdc can address not only conventional network issues such as bulk power transmission, asynchronous network interconnections, back-to-back ac system linking, and voltage/stability support to mention a few, but also niche markets such as the integration of large-scale renewable energy sources with the grid and most recently large onshore/offshore wind farms.
2,023 citations
Cites background from "An innovative modular multilevel co..."
...16(b)] is presented in [81] and examined for HVdc applications [82], [83]....
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TL;DR: A general overview of the basics of operation of the MMC along with its control challenges are discussed, and a review of state-of-the-art control strategies and trends is presented as mentioned in this paper.
Abstract: The modular multilevel converter (MMC) has been a subject of increasing importance for medium/high-power energy conversion systems. Over the past few years, significant research has been done to address the technical challenges associated with the operation and control of the MMC. In this paper, a general overview of the basics of operation of the MMC along with its control challenges are discussed, and a review of state-of-the-art control strategies and trends is presented. Finally, the applications of the MMC and their challenges are highlighted.
1,765 citations
Cites background from "An innovative modular multilevel co..."
...The first precharging scheme introduced in [55], [83], and [84] is based on using a dc circuit breaker (CB) and an auxiliary dc source with a voltage equal to the...
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...The peak-to-peak ripple magnitude of the SM capacitor voltages is given by [83]...
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TL;DR: In this paper, a modified phase-shifted carrier-based pulsewidth-modulation (PSC-PWM) scheme for modular multilevel converters (MMC) is presented.
Abstract: This paper describes a modified phase-shifted carrier-based pulsewidth-modulation (PSC-PWM) scheme for modular multilevel converters (MMC). In order to reduce the average device switching frequency, a reduced switching-frequency (RSF) voltage balancing algorithm is developed. This paper also proposes a circulating current suppressing controller (CCSC) to minimize the inner circulating current in an MMC. Based on the double line-frequency, negative-sequence rotational frame, the three-phase alternative circulating currents are decomposed into two dc components and are minimized by a pair of proportional integral controllers. Simulation results based on a detailed PSCAD/EMTDC model prove the effectiveness of the modified PSC-PWM method and the RSF voltage-balancing algorithm. The proposed CCSC not only eliminates the inner circulating current but also improves the quality of the converter ac output voltage. A simple loss evaluation demonstrates that the RSF voltage-balancing algorithm and the CCSC reduce the converter power losses.
1,183 citations
Cites background from "An innovative modular multilevel co..."
...Basic concepts and operation principles of MMC were studied in [7]–[10]....
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TL;DR: A review of the latest achievements of modular multilevel converters regarding the mentioned research topics, new applications, and future trends is presented in this article, where the authors present several attractive features such as a modular structure, the capability of transformer-less operation, easy scalability in terms of voltage and current, low expense for redundancy and fault tolerant operation, high availability, utilization of standard components, and excellent quality of the output waveforms.
Abstract: Modular multilevel converters have several attractive features such as a modular structure, the capability of transformer-less operation, easy scalability in terms of voltage and current, low expense for redundancy and fault tolerant operation, high availability, utilization of standard components, and excellent quality of the output waveforms. These features have increased the interest of industry and research in this topology, resulting in the development of new circuit configurations, converter models, control schemes, and modulation strategies. This paper presents a review of the latest achievements of modular multilevel converters regarding the mentioned research topics, new applications, and future trends.
1,123 citations
Cites methods from "An innovative modular multilevel co..."
...pose this converter as an interface between a three-phase and a single-phase systems, proposing the use of space vector modulation and a method for the capacitor design [7]....
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TL;DR: The operation of modular multilevel converter is described, an emerging and highly attractive topology for medium- and high-voltage applications and a new pulsewidth-modulation scheme for an arbitrary number of voltage levels is introduced and evaluated.
Abstract: This paper describes the operation of modular multilevel converter, an emerging and highly attractive topology for medium- and high-voltage applications. A new pulsewidth-modulation (PWM) scheme for an arbitrary number of voltage levels is introduced and evaluated. On the basis of this PWM scheme, the semiconductor losses are calculated, and the loss distribution is illustrated.
899 citations
Cites background or methods from "An innovative modular multilevel co..."
...So far, space-vector-modulation schemes [15], [23] and PWM schemes [24] have been introduced, and first experimental results have verified the function of the converter [25]– [28]....
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...This paper describes a new PWM scheme on the basis of the principles introduced in [15] and [23]....
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References
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TL;DR: The most important topologies like diode-clamped inverter (neutral-point clamped), capacitor-Clamped (flying capacitor), and cascaded multicell with separate DC sources are presented and the circuit topology options are presented.
Abstract: Multilevel inverter technology has emerged recently as a very important alternative in the area of high-power medium-voltage energy control. This paper presents the most important topologies like diode-clamped inverter (neutral-point clamped), capacitor-clamped (flying capacitor), and cascaded multicell with separate DC sources. Emerging topologies like asymmetric hybrid cells and soft-switched multilevel inverters are also discussed. This paper also presents the most relevant control and modulation methods developed for this family of converters: multilevel sinusoidal pulsewidth modulation, multilevel selective harmonic elimination, and space-vector modulation. Special attention is dedicated to the latest and more relevant applications of these converters such as laminators, conveyor belts, and unified power-flow controllers. The need of an active front end at the input side for those inverters supplying regenerative loads is also discussed, and the circuit topology options are also presented. Finally, the peripherally developing areas such as high-voltage high-power devices and optical sensors and other opportunities for future development are addressed.
6,472 citations
"An innovative modular multilevel co..." refers background in this paper
...For this application field multilevel converters with a high number of voltage levels seem to be the most suitable types, because of the need for series connection of semiconductors in combination with low voltage distortion on the line side [1]-[3]....
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...Finally, due to the expression of the reference vector by the determined surrounding vectors, the correspondent dwelling times have to be calculated [3]-[6]....
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08 Oct 1995
TL;DR: This paper presents three multilevel voltage source converters: (1) diode-clamp, (2) flying-capacitors, and (3) cascaded-inverters with separate DC sources.
Abstract: Multilevel voltage source converters are emerging as a new breed of power converter options for high-power applications. The multilevel voltage source converters typically synthesize the staircase voltage wave from several levels of DC capacitor voltages. One of the major limitations of the multilevel converters is the voltage unbalance between different levels. The techniques to balance the voltage between different levels normally involve voltage clamping or capacitor charge control. There are several ways of implementing voltage balance in multilevel converters. Without considering the traditional magnetic coupled converters, this paper presents three recently developed multilevel voltage source converters: (1) diode-clamp, (2) flying-capacitors, and (3) cascaded-inverters with separate DC sources. The operating principle, features, constraints, and potential applications of these converters are discussed.
3,232 citations
03 Oct 1999
TL;DR: This paper introduces a general space vector modulation algorithm for n-level three-phase power converters that is computationally extremely efficient and is independent of the number of levels of the power converter.
Abstract: This paper introduces a general space vector modulation algorithm for n-level three-phase power converters. This algorithm is computationally extremely efficient and is independent of the number of levels of the power converter. At the same time, it provides excellent insight into the operation of multilevel power converters.
800 citations
08 Oct 2000
TL;DR: In this paper, the inherent relations between sine-triangle and space-vector pulsewidth modulation schemes for three-level voltage-source inverters were studied and it was shown that the two schemes can function equivalently through proper selection of common-mode injections in the case of sine triangle modulation, or dwell times in equivalent redundant switching states in a space vector modulation scheme.
Abstract: This paper studies the inherent relations between sine-triangle and space-vector pulsewidth modulation schemes for three-level voltage-source inverters. It is shown that the two schemes can function equivalently through proper selection of common-mode injections in the case of sine-triangle modulation, or dwell times in equivalent redundant switching states in the case of space-vector modulation. Simulation and measurement results illustrate that understanding of these relations can lead to a more efficient and flexible three-level modulator with desired or optimal performance.
229 citations
30 Sep 2001
TL;DR: In this paper, the authors proposed a vector classification technique to determine sectors and durations associated with SVM in multi-level inverters, which is applicable to any number of levels.
Abstract: Space vector modulation (SVM) is commonly in digital implementations of three phase PWM modulators This paper proposes a general approach to determining sectors and durations associated with SVM in multi-level inverters The algorithm is exact, fast, and applicable to any number of levels It is based on a vector classification technique, which allows determination of the switching sequences and the calculation the switching instants in m-level inverters The proposed technique reduces software complexity, decreases the computation time, and increases the accuracy of the positioning of the switching instants, when compared with the conventional implementation of the SVM in multi-level converters Results are given for a 3-level inverter
29 citations