Dynamic Behavior Study of a VSC-HVDC System with SPWM Command Subjected to an Important Variation of Load

Author(s):  
Kokou Thophile Houngan ◽  
Richard Gilles Agbokpanzo ◽  
Kizito Codja ◽  
Pierre Aguemon ◽  
Christophe Espanet

To interconnect sources of production, it is necessary to watch that the technical parameters as tension, frequency and phase shift of the sources of production are equal. In Benin, it is difficult for the company in charge of the production and of the transport of the electricity to interconnect the production coming from Nigeria and that coming from Ghana because all the parameters are not equal. It is thus necessary to find a way to interconnect the sources of productions to satisfy not only the request in electrical energy but also to insure the continuity of the service and the stability of the electricity network [1,2]. In this work, we studied the dynamic behavior of the Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) system subjected to an important variation of load and commanded by the Sine-triangle Pulse Width Modulation ( SPWM) to improve the quality of the electrical energy. We developed thus first of all the electric model of all the constituents of the system. These models allowed designing easily the control systems of the static converters VSC (the rectifier and the inverter). The simulation of the inverter showed that the rate of distortion of harmonious varied considerably according to the load for important variations of load. The solution brought by this work is the elaboration of a control system to vectorial PWM who improves the rate of distortion of harmonious.

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Guo-Jie Li ◽  
Si-Ye Ruan ◽  
Tek Lie

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.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2260
Author(s):  
Fan Cheng ◽  
Lijun Xie ◽  
Zhibing Wang

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.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3554
Author(s):  
Naushath M. Haleem ◽  
Athula D. Rajapakse ◽  
Aniruddha M. Gole ◽  
Ioni T. Fernando

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.


2013 ◽  
Vol 860-863 ◽  
pp. 2269-2274
Author(s):  
Hao Yang Cui ◽  
Yong Peng Xu ◽  
Jun Jie Yang ◽  
Jun Dong Zeng ◽  
Zhong Tang

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.


2019 ◽  
Vol 217 ◽  
pp. 01004
Author(s):  
Yang Zhou ◽  
Stefan Dalhues ◽  
Ulf Häger

The integration of the voltage-source converter based high voltage direct current (VSC-HVDC) system makes the set-point of its active power adaptive to the changes in the power flow, and contributes to the curative congestion management. To further exploit the dynamic behavior of a hybrid AC/DC power system in curative congestion management scenarios, this paper investigates a novel control scheme for voltage angle droop controlled HVDC (VAD-HVDC) systems. The proposed scheme to alleviate the circuit overload is estimated firstly by calculating the severity index when the power flow changes under N-1 situations. Then the voltage angle controlled HVDC system is applied on the modified IEEE 39-bus 10-machine test power system for the time-domain simulation. The dynamic behavior in the HVDC station validates that the VAD control can stabilize the DC voltage and possess a good ability against interference. In addition, the dynamic characteristics analysis on the AC transmission lines proves that the hybrid AC/DC system integrated with the VAD controlled HVDC system are in possession of good stability after the N-1 contingency event. The VAD controller employed in the HVDC system is capable of effective congestion management to mitigate the critical loadings on the transmission lines.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1363
Author(s):  
Harith R. Wickramasinghe ◽  
Pingyang Sun ◽  
Georgios Konstantinou

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.


2010 ◽  
Vol 61 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Mohamed Khatir ◽  
Sid-Ahmed Zidi ◽  
Samir Hadjeri ◽  
Mohammed-Karim Fellah

Dynamic Performance of a Back-to-Back HVDC Station Based on Voltage Source Converters The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. This new DC transmission is known as "HVDC Light or "HVDC Plus by leading vendors. Due to the use of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC. In this paper, the scenario of back-to-back VSC-HVDC link connecting two adjacent asynchronous AC networks is studied. Control strategy is implemented and its dynamic performances during disturbances are investigated in MATLAB/Simulink program. The simulation results have shown good performance of the proposed system under balanced and unbalanced fault conditions.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3097
Author(s):  
Roberto Benato ◽  
Antonio Chiarelli ◽  
Sebastian Dambone Sessa

The purpose of this paper is to highlight that, in order to assess the availability of different HVDC cable transmission systems, a more detailed characterization of the cable management significantly affects the availability estimation since the cable represents one of the most critical elements of such systems. The analyzed case study consists of a multi-terminal direct current system based on both line commutated converter and voltage source converter technologies in different configurations, whose availability is computed for different transmitted power capacities. For these analyses, the matrix-based reliability estimation method is exploited together with the Monte Carlo approach and the Markov state space one. This paper shows how reliability analysis requires a deep knowledge of the real installation conditions. The impact of these conditions on the reliability evaluation and the involved benefits are also presented.


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