Design of a Modular, High Step-Up Ratio DC–DC Converter for HVDC Applications Integrating Offshore Wind Power

Hu, Yihua; Zeng, Rong; Cao, Wenping; Zhang, Jiangfeng; Finney, S.J.

doi:10.1109/tie.2015.2510975

Cited by 67 publications

(31 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some topologies and general modular dc-dc converters have been proposed to address these challenges [18], [19]. Additionally, in some other applications such as offshore wind farms, the collector system can be done with pure dc-dc conversion [20]- [22]. These growing needs for high step ratio dc-dc conversion bring new challenges to the configuration and control of power electronics based system.…”

Section: Introductionmentioning

confidence: 99%

Large Step Ratio Input-Series–Output-Parallel Chain-Link DC–DC Converter

Zhang

Tian

Xiang

et al. 2019

IEEE Trans. Power Electron.

View full text Add to dashboard Cite

High-voltage and high-power dc-dc conversion is key to dc transmission, distribution and generation, which require compact and efficient dc transformers with large step ratios. This paper introduces a dc-dc converter with the input-series-outputparallel (ISOP) arrangement of multiple high step ratio subconverter units. Each sub-converter unit is an isolated modular dc-dc converter with a stack of half-bridge cells chopping the dc down to low voltage level. The transformer provides galvanic isolation and additional step ratio. The converter achieves a large step ratio due to the combination of the series-parallel configuration, the modular cells, and the isolation transformer. The proposed dc-dc converter is analyzed in a 30 kV to 1 kV, 1 MW application to discuss the operation performance, tradeoffs, power efficiency and selection of components. Finally, the converter is validated through a laboratory down-scaled prototype.

show abstract

Section: Introductionmentioning

confidence: 99%

Large Step Ratio Input-Series–Output-Parallel Chain-Link DC–DC Converter

Zhang

Tian

Xiang

et al. 2019

IEEE Trans. Power Electron.

View full text Add to dashboard Cite

show abstract

“…The control headroom Ch shown in (10), is the additional negative voltage available over and above that which will be needed to maintain the negative steady-state current. A larger value allows a faster transition of current and a waveform closer to square.…”

Section: B Stage 2: Force Current Reversal (T1-t2)mentioning

confidence: 99%

“…Although there is no full-scale practical project for dc tap up to date, it has attracted much interest in recent years for both academic research and industrial development to satisfy the demand and architecture for future dc grids [10]- [16]. It could collect power from small-scale offshore wind farms (OWF) near the cable routes by tapping into the HVDC link directly [10], [11], and the LPHR conversion can also tap out a small fraction of the link power to service demand in remote communities with inadequate ac supplies but which are crossed by the HVDC corridors [12]- [14]. A growing role for conversion between HVDC and Medium Voltage Direct Current (MVDC) grids is also anticipated [15], [16].…”

mentioning

confidence: 99%

A Compact Modular Multilevel DC–DC Converter for High Step-Ratio MV and HV Use

Xiang

Zhang

Luth

et al. 2018

IEEE Trans. Ind. Electron.

View full text Add to dashboard Cite

In multi-terminal dc networks or future dc grids, there is an important role for high step-ratio dc-dc conversion to interface a high voltage network to lower voltage infeeds or offtakes. The efficiency and controllability of dc-dc conversion will be expected to be similar to modular multi-level ac-dc converters. This paper presents a modular multilevel dc-dc converter with a high step-ratio for medium voltage and high voltage applications. Its topology on high-voltage side is derived from the half-bridge single-phase inverter with stacks of sub-modules replacing each of the switch positions. A near-square-wave current operation is proposed which achieves near-constant instantaneous power for single-phase conversion, leading to reduced stack capacitor and filter volume and also increased the power device utilization. A controller for energy balancing and current tracking is designed. The soft-switching operation on the low-voltage side is demonstrated. The high step-ratio is accomplished by combination of inherent half-bridge ratio, sub-module stack modulation and transformer turns-ratio, which also offers flexibility to satisfy wide-range conversion requirement. The theoretical analysis of this converter is verified by simulation of a full-scale 40MW, 200 kV converter with 146 sub-modules and also through experimental testing of a down-scaled prototype at 4.5 kW, 1.5 kV with 18 sub-modules. Index Terms-Modular multilevel converter, compact volume, high step-ratio, dc grids. NOMENCLATURE Ch Control headroom D Duty-cycle of the near-square-wave ES Sum of the energy stored in all capacitors ETs, EBs Energy stored in the top stack and bottom stack fo, fs Operation frequency, switching frequency fr SM sorting and selection frequency iBac AC component of the bottom stack current Manuscript

show abstract

“…Due to the advancements of power electronics technology, high-power de-de converters can provide power flow control functions in MTDC grids; enhancing the flexibility of grid operation [16]- [18], [23] , [31]- [34]. By adjusting the de-de converter transformation ratio, the voltage at one terminal of the converter, or the power flowing through the converter, can be regulated, adding a degree of freedom to the control of the MTDC grid [22] .…”

Section: Flexible Operation Of Mtdc Gridsmentioning

confidence: 99%

Flexible Control of Power Flow in Multiterminal DC Grids Using DC–DC Converter

Rouzbehi

Candela

Luna

et al. 2016

IEEE J. Emerg. Sel. Topics Power Electron.

View full text Add to dashboard Cite

Abstract-This paper proposes an efficient control framework that utilizes de-de converters to achieve flexible power flow control in multiterminal de (MTDC) grids. The de-de converter employed in this paper is connected in cascade with the de transmission line, and is therefore named cascaded power flow controller (CPFC). In this paper, a two-layer control strategy is developed for the operation and control of voltage source converter stations and CPFC station in MTDC grids. At the primary control layer, a novel differential voltage droop control is developed, while at the secondary control layer, a modified de power flow algorithm-employing the new CPFC frameworkis implemented. The overall control strategy enables the CPFC to regulate the power flow in the de transmission line. The primary control guarantees the transient stability of the CPFC, and the secondary control system ensures the desired steady-state operation. The proposed voltage droop control framework helps the MTDC grid to remain stable in the event of a communication failure between the primary and secondary control layers. Static analysis and dynamic simulations are performed on the CIGRE B4 de grid test system, in order to confirm the effectiveness of the proposed control framework for power flow regulation in MTDC grids.Index Terms-CIGRE B4 de grid, de power flow control, multiterminal de (MTDC) grid, power system control, voltage droop control.

show abstract

Design of a Modular, High Step-Up Ratio DC–DC Converter for HVDC Applications Integrating Offshore Wind Power

Cited by 67 publications

References 30 publications

Large Step Ratio Input-Series–Output-Parallel Chain-Link DC–DC Converter

Large Step Ratio Input-Series–Output-Parallel Chain-Link DC–DC Converter

A Compact Modular Multilevel DC–DC Converter for High Step-Ratio MV and HV Use

Flexible Control of Power Flow in Multiterminal DC Grids Using DC–DC Converter

Contact Info

Product

Resources

About