The use of averaged-value model of modular multilevel converter in DC grid

Xu, Jianzhong; Gole, A.M.; Zhao, Chengyong

doi:10.1109/pesgm.2015.7285775

Cited by 15 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 shows the three-terminal HVDC system considered. All converter stations are modeled as HBMMCs using modified average models [7][8][9]23]. The system parameters are listed in Table I.…”

Section: Consideration Of DC Fault-tolerant Operationmentioning

confidence: 99%

“…Station S 3 is blocked due to over-current, while S 1 and S 2 remain operational. The diodes in S 3 are protected using bypass switches to avoid being damaged from high fault current and ACCB is used to isolate the converter from connected AC network [5][6][7][8][9].…”

Section: B Influence Of Protection Structures On Fault Currentsmentioning

confidence: 99%

“…The losses introduced by short-circuit currents expose the diodes to thermal stresses and are usually measured by the integral of the surge current I 2 t. ABB, Infineon and Dynex provide IGBT and the anti-parallel diode with 3.3kV voltage rating and their diode I 2 t are 911kA 2 s, 730kA 2 s and 720kA 2 s respectively [4]. Bypass elements, typically thyristors, are used to protect the freewheeling diodes of the HB sub-modules (SMs) in MMC [5][6][7][8][9]. However, prolonged system outage still occurs.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Continuous Operation of Radial Multiterminal HVDC Systems Under DC Fault

Holliday

et al. 2016

IEEE Trans. Power Delivery

149

113

View full text Add to dashboard Cite

Abstract -For a large multi-terminal HVDC system, it is important that a DC fault on a single branch does not cause significant disturbance to the operation of the healthy parts of the DC network. Some DC circuit breakers (DCCBs), e.g. mechanical type, have low cost and power loss, but have been considered unsuitable for DC fault protection and isolation in a multi-terminal HVDC system due to their long opening time. This paper proposes the use of additional DC passive components and novel converter control combined with mechanical DCCBs to ensure that the healthy DC network can continue to operate without disruption during a DC fault on one DC branch. Two circuit structures, using an additional DC reactor, and a reactor and capacitor combination, connected to the DC-link node in a radial HVDC system are proposed to ensure over-current risk at the converters connected to the healthy network is minimized before the isolation of the faulty branch by mechanical DCCBs. Active control of DC fault current by dynamically regulating the DC components of the converter arm voltages is proposed to further reduce the fault arm current. Simulation of a radial three-terminal HVDC system demonstrates the effectiveness of the proposed method.

show abstract

“…1 shows the three-terminal HVDC system considered. All converter stations are modeled as HBMMCs using modified average models [7][8][9]23]. The system parameters are listed in Table I.…”

Section: Consideration Of DC Fault-tolerant Operationmentioning

confidence: 99%

Section: B Influence Of Protection Structures On Fault Currentsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Continuous Operation of Radial Multiterminal HVDC Systems Under DC Fault

Holliday

et al. 2016

IEEE Trans. Power Delivery

149

113

View full text Add to dashboard Cite

show abstract

“…To reduce computation time and accelerate the simulation, average models are used to evaluate MMC performance in normal operation and during a dc fault. In the prior MMC model [13] only one equivalent capacitor is employed. Thus the state equation that describes MMC behaviour is significantly reduced, resulting in model inaccuracy.…”

Section: Revised Generic MMC Average Modelmentioning

confidence: 99%

“…Thus the state equation that describes MMC behaviour is significantly reduced, resulting in model inaccuracy. [13]. But the modified average model adopted in this paper, uses 6 capacitors and can represent the MMC behavior accurately under various operating conditions, including a pole-to-pole dc fault The modified average model in Fig.2 provides reliable representation of MMC behavior during dc fault ride-through operation.…”

Section: Revised Generic MMC Average Modelmentioning

confidence: 99%

Mechanism to Regulate DC Fault Currents in DC Solid State Transformers under Continuous Working Performance of Multi-Terminal HVDC Systems

Chiranth¹

2017

IJRASET

View full text Add to dashboard Cite

Once the pole-to-pole dc fault occurs in a multi-terminal HVDC system, it is desirable that the stations and dc solidstate transformers on healthy cables continue to operate, rather than blocking. To reduce the fault current of a modular multilevel converter based dc solid-state transformer, active fault current control is proposed, where the dc and ac components of fault arm currents are controlled independently. By dynamically regulating the dc offset of the arm voltage rather than being set at half the rated dc voltage, the dc component in the fault current is reduced significantly. Additionally, reduced ac voltage operation of the dc solid-state transformer during the fault is proposed, where the ac voltage of transformer is actively restricted in the controllable range of both converters in the transformer to effectively suppress the ac component of the fault current. The fault arm current peak and the energy absorbed by the surge arrester in the dc circuit breakers are reduced by 31.8% and 4.9% respectively, thereby lowering the capacities of switching devices and circuit breakers. The novel active fault current control mechanism and the essential control strategy are presented and simulation results confirm its feasibility. I. INTRODUCTIONThe deregulation of international energy markets and the trend to decentralized power generation are increasing the demand for advanced power electronic systems. For this application field multilevel converters with a high number of voltage levels seem to be the most suitable types, MMC was first proposed for HVDC applications at 2003from a Marquardt and it is first employed commercially in Trans Bay Cable project in a San Francisco. In the present scenario the Modular Multi-Level Converter (MMC) is becoming the most common type of a voltage source converter for HVDC applications. DC fault protection is an issue to be resolved for the development of modular multilevel converter (MMC) based HVDC transmission systems. [1][2][3][4]. The dc circuit breakers (DCCBs) have the potential to isolate a dc fault and protect stations from damage and limiting reactors are series connected with the fast acting DCCBs (e.g. solid-state DCCBs, hybrid DCCBs) to limit the fault current di/dt and decrease the fault current peak. Recently, the concept of the dc solid-state transformer (DCT) has been proposed which uses active controlled power electronic components to optimize converter performance. [6][7][8][9]. Similar to the ac transformer, the dc solid-state transformer can adapt the dc voltage to any higher or lower voltage level. By blocking all the converters of the dc solid-state transformer, dc faults can be isolated without significantly affecting the healthy system parts. Thus, the dc solid-state transformer appears the only approach to connect and interconnect existing HVDC links with different dc voltages. These transformers are available in different configurations which include the thyristor based solid-state transformer[10],the dual-active bridge (DAB) transformer [1...

show abstract

Large step size electromagnetic transient simulations by matrix transformation‐based shifted‐frequency phasor models

Tang²,

Shu

2020

IET Generation, Transmission & Distribution

View full text Add to dashboard Cite

The use of averaged-value model of modular multilevel converter in DC grid

Cited by 15 publications

References 0 publications

Continuous Operation of Radial Multiterminal HVDC Systems Under DC Fault

Continuous Operation of Radial Multiterminal HVDC Systems Under DC Fault

Mechanism to Regulate DC Fault Currents in DC Solid State Transformers under Continuous Working Performance of Multi-Terminal HVDC Systems

Large step size electromagnetic transient simulations by matrix transformation‐based shifted‐frequency phasor models

Contact Info

Product

Resources

About