scholarly journals Research on Serial VSC-LCC Hybrid HVdc Control Strategy and Filter Design Scheme

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2260
Author(s):  
Fan Cheng ◽  
Lijun Xie ◽  
Zhibing Wang
Keyword(s):  
Reactive Power ◽  
Filter Design ◽  
Control Strategies ◽  
Short Circuit ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Level Control ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Design Scheme

This paper investigated the characteristics of a novel type of hybrid high voltage direct current (HVdc) converter, which is composed by line commutated converter series with voltage source converter. The system and valve level control strategies are introduced, which can provide ac system voltage support. A novel filter design scheme composed by resonant filers for hybrid HVdc are also proposed, which can decrease the capacity of reactive power compensation equipment without deteriorate harmonic characteristics. The ac voltage of HVdc fluctuation level caused by transmitted power variation will be effectively reduced, with the coordination between filter design scheme and converter control. In addition, the influence of ac grid strength is also analyzed by equivalent source internal impedance represented by short circuit ratio (SCR). Finally, the +800 kV/1600 MW hybrid HVdc system connecting two ac grids under different SCR cases are studied, and the PSCAD/EMTDC simulation results have validated the effectiveness for proposed strategy.

scholarly journals Power Stability Analysis and Evaluation Criteria of Dual-Infeed HVDC with LCC-HVDC and VSC-HVDC

2021 ◽  
Vol 11 (13) ◽  
pp. 5847
Author(s):  
Xinglong Wu ◽  
Zheng Xu ◽  
Zheren Zhang
Keyword(s):  
Reactive Power ◽  
Short Circuit ◽  
Evaluation Criteria ◽  
Stability Margin ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Power Stability ◽  
Hvdc System ◽  
Voltage Control Mode

This paper analyzes the power stability of the hybrid dual-infeed high-voltage direct-current (HVDC) system containing a line commutated converter-based HVDC (LCC-HVDC) and a voltage source converter-based HVDC (VSC-HVDC). First, the concept and the calculation method of power stability for the hybrid dual-infeed HVDC system are introduced. Second, the influence of VSC-HVDC on the power stability of the system is investigated. Third, the relationship between the power stability and the effective short circuit ratio (ESCR) is discussed under different system parameters. Then, the value range of the critical effective short circuit ratio is determined. Finally, the evaluation criteria of power stability are proposed. The results show that the evaluation criteria of the single-infeed LCC-HVDC system can still be used, if the VSC-HVDC is in constant AC voltage control mode; if the VSC-HVDC is in constant reactive power control mode, the hybrid dual-infeed HVDC system cannot operate stably when the ESCR is less than 2.0 and can operate stably with high power stability margin when the ESCR is greater than 3.0. The ESCR index can still be used to measure the power stability of the hybrid dual-infeed HVDC system.

Real power regulation design for multi-terminal VSC-HVDC systems

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Guo-Jie Li ◽  
Si-Ye Ruan ◽  
Tek Lie
Keyword(s):  
Control Strategy ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Real Power ◽  
The Real ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Power Regulation ◽  
Regulation Functions

AbstractA multi-terminal voltage-source-converter (VSC) based high voltage direct current (HVDC) system is concerned for its flexibility and reliability. In this study, a control strategy for multiple VSCs is proposed to auto-share the real power variation without changing control mode, which is based on “dc voltage droop” power regulation functions. With the proposed power regulation design, the multiple VSCs automatically share the real power change and the VSC-HVDC system is stable even under loss of any one converter while there is no overloading for any individual converter. Simulation results show that it is effective to balance real power for power disturbance and thus improves operation reliability for the multi-terminal VSC-HVDC system by the proposed control strategy.

scholarly journals Minimum Short Circuit Ratio Requirement for MMC-HVDC Systems Based on Small-Signal Stability Analysis

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3283 ◽  
Author(s):  
Zheren Zhang ◽  
Liang Xiao ◽  
Guoteng Wang ◽  
Jian Yang ◽  
Zheng Xu
Keyword(s):  
Reactive Power ◽  
Short Circuit ◽  
Small Signal ◽  
Small Signal Stability ◽  
Ratio Requirement ◽  
Planning Stage ◽  
Hvdc System ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Signal Stability

This paper determines the minimum short circuit ratio (SCR) requirement for a modular multilevel converter based high-voltage direct current (MMC-HVDC) transmission systems. Firstly, a simplified model of MMC is introduced; the MMC is represented by its AC and DC side equivalent circuit. Next, by linearizing the MMC subsystem and the DC network subsystem, the deduction of the small-signal models of MMC subsystem, the small-signal model of the DC network and MMC-HVDC are carried out successively. Thirdly, the procedure for determining the minimum SCR requirement of MMC-HVDC is described. Finally, case studies are performed on a two-terminal MMC-HVDC system under four typical control schemes. The results show that the restraint factors for the rectifier MMC is predominantly the voltage safety limit constraint, and the restraint factors for the inverter MMC are mainly the phase locked loop (PLL) or the outer reactive power controller. It is suggested that the minimum SCR requirement for the sending and the receiving systems should be 2.0 and 1.5 in the planning stage.

scholarly journals A Selective Fault Clearing Scheme for a Hybrid VSC-LCC Multi-Terminal HVdc System

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3554
Author(s):  
Naushath M. Haleem ◽  
Athula D. Rajapakse ◽  
Aniruddha M. Gole ◽  
Ioni T. Fernando
Keyword(s):  
High Capacity ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Circuit Breakers ◽  
Hvdc System ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Clearing Functions ◽  
Transmission Structure ◽  
The Impact

A selective fault clearing scheme is proposed for a hybrid voltage source converter (VSC)-line commutated converter (LCC) multi-terminal high voltage direct current (HVdc) transmission structure in which two small capacity VSC stations tap into the main transmission line of a high capacity LCC-HVdc link. The use of dc circuit breakers (dc CBs) on the branches connecting to VSCs at the tapping points is explored to minimize the impact of tapping on the reliability of the main LCC link. This arrangement allows clearing of temporary faults on the main LCC line as usual by force retardation of the LCC rectifier. The faults on the branches connecting to VSC stations can be cleared by blocking insulated gate bipolar transistors (IGBTs) and opening ac circuit breakers (ac CB), without affecting the main line’s performance. A local voltage and current measurement based fault discrimination scheme is developed to identify the faulted sections and pole(s), and trigger appropriate fault recovery functions. This fault discrimination scheme is capable of detecting and discriminating short circuits and high resistances faults in any branch well before 2 ms. For the test grid considered, 6 kA, 2 ms dc CBs can easily facilitate the intended fault clearing functions and maintain the power transfer through healthy pole during single-pole faults.

A Fault Diagnosis Method in VSC-HVDC Simulation System Based on BRBP Neural Networks

2013 ◽  
Vol 860-863 ◽  
pp. 2269-2274
Author(s):  
Hao Yang Cui ◽  
Yong Peng Xu ◽  
Jun Jie Yang ◽  
Jun Dong Zeng ◽  
Zhong Tang
Keyword(s):  
Neural Networks ◽  
Fault Diagnosis ◽  
Back Propagation ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Current Transmission ◽  
Diagnosis Method ◽  
Dc Current

As the feature of faulty signal in high voltage direct current transmission technology based on voltage source converter (VSC-HVDC) system is complicated to extract and its difficult to carry on the fault diagnosis. On the basis of the PSCAD simulation model of VSC-HVDC system, the DC current faulty signal is analyzed. Then, the wavelet analysis method was adopted to extract the eigenvector of faulty signal, and combined with method of Bayesian regularization back-propagation (BRBP) neural networks, the system fault was identified. The simulation results show that the method is more efficiently and more rapidly than the adding momentum BP neural network on the VSC-HVDC system faults diagnosing.

scholarly journals Vector Control of VSC HVDC System under Single Line to Ground Fault Condition

2018 ◽  
Vol 7 (1) ◽  
pp. 59
Author(s):  
Prabodha Kumar Rath ◽  
Kanhu Charan Bhuyan
Keyword(s):  
Vector Control ◽  
Reactive Power ◽  
Control Method ◽  
System Stability ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Control Loop ◽  
Hvdc System ◽  
Ground Fault

<span lang="EN-US">This paper proposes a model of a VSC (voltage source converter) based Back to Back HVDC system and its control technique under fault condition. From the mathematical model of the system relationship between the controlling and the controlled variables is determined to control the system parameters. An appropriate vector control technique is used to control active and reactive power and to maintain DC link voltage. The proposed controlling unit consists of outer control loop and inner control loop which effectively damped out the system oscillation and maintains the system stability. The validity of the model and the feasibility of the control method have been proved by the simulation results. In this paper the system performance is studied under fault condition is studied.</span>

Research on DC Voltage Control Strategies for Typical Four-Terminal HVDC System

2014 ◽  
Vol 521 ◽  
pp. 222-228
Author(s):  
Kai Wang ◽  
Hai Shun Sun ◽  
Yu Hua ◽  
Yuan Liu ◽  
Wei Xing Lin ◽  
...  
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Control Strategy ◽  
Alternative Energy ◽  
Control Strategies ◽  
Future Trend ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage ◽  
High Voltage Direct Current

The continuous development of alternative energy has put forward higher requirement for electricity transmission. To cope with its fluctuation characteristics, high voltage direct current (HVDC) technology has received more attention. Voltage Source Converter (VSC) based Multi-Terminal High Voltage Direct Current (MTDC) represents the future trend of HVDC technology. This paper mainly focuses on the control strategies of a four-terminal VSC based MTDC power transmission system. The operation characteristic of the system was studied, and the proposed two control strategies, master-slave control strategy and DC voltage droop control strategy, were verified through simulations. The latter control strategy was proved to be performing well under various conditions, including converter station disconnection and faults at AC side of the converter.

scholarly journals Interoperability of Modular Multilevel and Alternate Arm Converters in Hybrid HVDC Systems

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1363
Author(s):  
Harith R. Wickramasinghe ◽  
Pingyang Sun ◽  
Georgios Konstantinou
Keyword(s):  
Control Structure ◽  
State Of The Art ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Control Functions ◽  
Complex Hybrid

This paper demonstrates the interoperability of an emerging alternate arm converter (AAC) with the state-of-the-art modular multilevel converter (MMC) in high-voltage direct current (HVDC) systems based on a hybrid VSC-HVDC system. The paper also showcases the parameter derivation of the hybrid HVDC system and its detailed control structure. The study provides preliminary steps towards detailed analysis of AAC interoperability in complex hybrid dc grid configurations. A detailed set of results based on the 800 MVA hybrid voltage source converter (VSC)-HVDC system showcases the interoperability performance of the AAC under different operating scenarios and verifies its associated control functions.

Novel Configuration of 60-Pulse Voltage Source Converter for STATCOM Application

2007 ◽  
Vol 8 (5) ◽  
Author(s):  
Wulue Pan ◽  
Zheng Xu ◽  
Jing Zhang
Keyword(s):  
Computer Simulation ◽  
Control Strategies ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage ◽  
Current Harmonic ◽  
Hvdc System ◽  
And Control ◽  
Injection Ratio ◽  
Auxiliary Circuit

The proposed voltage source converter is composed of a series double bridge converter with an auxiliary circuit. The auxiliary circuit injects DC voltage via the mid point of the double bridge converter. The injection ratio and frequency are chosen to convert the standard 12-pulse into 60-pulse configuration without PWM or increasing the number of bridges, thus the voltage and current harmonic can fulfill the THD limit without a conventional filter. The converter is operated under fundamental frequency for the main bridges, thus its switching lose is low. The converter can be widely used in the STATCOM and HVDC system. The paper describes the principles and control strategies of the proposed converter. The operational feasibility of the proposed converter is verified by computer simulation using the PSCAD/EMTDC package.

Sign in / Sign up

Export Citation Format

Share Document