Modular multilevel converter with high-frequency transformers for interfacing hybrid DC and AC microgrid systems

Liu, Yusi; Escobar-Mejía, Andrés; Farnell, Chris; Zhang, Yuzhi; Balda, Juan Carlos; Mantooth, H. Alan

doi:10.1109/pedg.2014.6878625

Cited by 22 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many researchers worked on the issues incorporated with interfacing the MG to the main grids, and solutions have been presented in the literature [33][34][35][36]. During the operation of the microgrid in either IS/GC mode or transition periods.…”

Section: Control Strategies Of Ac/dc Mgmentioning

confidence: 99%

A Comprehensive Review on Power Converters Control and Control Strategies of AC/DC Microgrid

Ansari¹,

Chandel²,

Tariq

2021

IEEE Access

View full text Add to dashboard Cite

Owing to the smart lifestyle, environmental consciousness, and dwindling fossil fuel supplies, there is a huge demand for clean and green energy. Microgrid (MG) is a crucial approach to renewable and clean energy. Because of the success of the AC utility grid and the growing demand for critical loads, it is very convenient to provide AC/DC MG that can easily satisfy both the alternating current (AC) MG and the direct current (DC) MG requirements. Due to uncertainty in load variations, main grid failures, intermittent power generations from renewable energy sources (RESs), the synchronization and interconnection of different power converters are the paramount issues in the control of AC/DC MG. This paper presents an overview-oriented state of the art in the recent advancement in control strategies of AC/DC MG and its associated power converters control. Based on recent research, this paper summarizes unobstructed views on different topologies, types of power converters, power converter controls, and control strategies of AC/DC MG. Finally, it identified some future challenges that need to be addressed in order to develop a sustainable and reliable control strategy for AC/DC MG. This paper will serve as a guide for researchers. INDEX TERMS Distributed generation, Microgrids, AC/DC Microgrid, Centralized control, Decentralized control I. INTRODUCTION MGs compromise different RESs, i.e., PV cells, windmills, energy-storing systems (ESS), diesel generator sets, and small hydropower plants, as discussed in the [1,2]. With the advancements in power semiconductor devices, the integration of RESs with leading utility or MG becomes so more accessible. Based on the adopted topology, there are three types of MGs, classified as DC MG, AC MG, and AC/DC MG or hybrid MG [3]. The DC MGs are preferred to supply critical loads like computers, operation theatres, and billing counters. Whereas the AC MGs are preferred in supplying all loads during off-grid or on-grid. The AC/DC MG possesses the characteristics of both DC MG and AC MG. Since begin, in these types of MGs, the power converters are connected in parallel with the MG bus-bar and belong to the parallel topology of MG. Recently a seriescascaded MG topology is being investigated. Inam Ullah Nutkani and et al. in [4] has presented a series-cascaded AC MG topology to integrate the non-dispatchable RESs to the MG and offered its advantages and disadvantages over the parallel topology. Fig.1 shows the different topological advances of MGs.

show abstract

Section: Control Strategies Of Ac/dc Mgmentioning

confidence: 99%

A Comprehensive Review on Power Converters Control and Control Strategies of AC/DC Microgrid

Ansari¹,

Chandel²,

Tariq

2021

IEEE Access

View full text Add to dashboard Cite

show abstract

“…8). [31][32][33] It is clearly observed that the coil is charged (V sm is positive) as the IGBTs are turned on and discharged (V sm is negative) as the IGBTs are turned off. Over a control cycle, the average value V smav of V sm determining the charging (or discharging) power of the coil is a function of the duty ratio defined as the ratio of the IGBT on-time with respect to the cycle period.…”

Section: Controllers Of Smesmentioning

confidence: 99%

A novel transient rotor current control scheme of a doubly-fed induction generator equipped with superconducting magnetic energy storage for voltage and frequency support

Shen¹,

Ke²,

Sun³

et al. 2015

Chinese Phys. B

View full text Add to dashboard Cite

A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator (DFIG) equipped with a superconducting magnetic energy storage (SMES) device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter (GSC) is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter (RSC) has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive (priority) and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method.

show abstract

“…Featuring multiport capability and modular structure, these two types of PETs are commonly studied [8]. The MMC-PET [9]- [11] are usually applied when high-voltage DC bus is required. Generally, the topology of a CHB based PET inter-connecting three-phase medium-voltage (MV) AC and low-voltage (LV) DC grid is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Capacitor Voltage Ripple Minimization of a Modular Three-Phase AC/DC Power Electronics Transformer With Four-Winding Power Channel

Cheng

et al. 2020

IEEE Access

View full text Add to dashboard Cite

Power electronic transformer (PET) with modular cascaded structure has become a flexible interface between AC and DC grids. Nonetheless, the notable 2 nd-order ripple power introduced from the AC source requires considerable energy storage in the module capacitors, which is likely to degrade the overall power density and increase system cost. In this paper, a power channel based four-winding PET (PC-PET) is proposed to address such an issue. Owing to the phase-crossing power channels, the low-frequency ripples can cancel each other through magnetic flux counteracting. To improve the accuracy of power decoupling, the effect compromised by inconsistent windings is considered. Accordingly, a proportional-resonant (PR) control based power decoupling strategy for PC-PET incorporated with power balance is proposed to decouple the three-phase low-frequency ripple powers, and minimize the voltage ripple in module capacitors. Additionally, the improvement of power density is discussed based on analyses on power losses, capacitor volume and transformer volume. Simulation and experimental results verified the validity of proposed control strategies.

show abstract

Modular multilevel converter with high-frequency transformers for interfacing hybrid DC and AC microgrid systems

Cited by 22 publications

References 15 publications

A Comprehensive Review on Power Converters Control and Control Strategies of AC/DC Microgrid

A Comprehensive Review on Power Converters Control and Control Strategies of AC/DC Microgrid

A novel transient rotor current control scheme of a doubly-fed induction generator equipped with superconducting magnetic energy storage for voltage and frequency support

Capacitor Voltage Ripple Minimization of a Modular Three-Phase AC/DC Power Electronics Transformer With Four-Winding Power Channel

Contact Info

Product

Resources

About