Aspects on infeed of multiple HVDC into one ac network (original) (raw)
Related papers
Study of a Multi-Infeed HVDC System
2009
There are serious concerns relating to a MultiInfeed HVDC system when feeding a weak AC network. Typical issues concerning multi-infeed configurations are: need for coordination of the recovery control, need for different DC modulation strategies to stabilize the system, possibility of voltage instability of the area receiving large amount of power from multiple HVDC links and the risk of mutual commutation failures. In contrast, if the area receiving electrical power from multiple HVDC transmission links is relatively strong due to the presence of large amount of generation units nearby there are still some questions that need to be investigated such as the issues underlining the operation of such a multi-infeed system, the proper design of the controls of the HVDC systems and the system dynamic performance under extreme contingencies. This paper investigates into an example of such a multi-infeed HVDC system. The authors have performed small signal analysis of the system to assess...
Case Study of a Multi-Infeed HVDC System
There are serious concerns relating to a Multi-Infeed HVDC system when feeding a weak AC network. Typical issues concerning multi-infeed configurations are: need for coordination of the recovery control, need for different DC modulation strategies to stabilize the system, possibility of voltage instability of the area receiving large amount of power from multiple HVDC links and the risk of mutual commutation failures. In contrast, if the area receiving electrical power from multiple HVDC transmission links is relatively strong due to the presence of large amount of generation units nearby there are still some questions that need to be investigated such as the issues underlining the operation of such a multi-infeed system, the proper design of the controls of the HVDC systems and the system dynamic performance under extreme contingencies. This paper investigates into an example of such a multi-infeed HVDC system. The authors have performed small signal analysis of the system to assess instability associated with the control modes. Electromechanical and voltage stability analysis were performed for harmful contingencies. Dynamic performance analysis was also carried out to analyze the interaction amongst various HVDC inverters during disturbances.
Stability improvement of a HVDC transmission link between weak AC systems by multi-terminal scheme
2013 Africon, 2013
High Voltage Direct Current (HVDC) schemes are becoming a more attractive solution as they have been used extensively in interconnected weak power AC systems. But, the problem of voltage stability for weak AC systems interconnected by a DC link is critical especially during islanding conditions. The approach to improve more on the stability of such system would be to device a means of injecting locally controlled dc power on the dc-link transmission corridor forming a radial multi-terminal HVDC. However, continuous injection of DC power on the dc line of the VSC HVDC link though will increase the power transfer capability of the system but should have a limit otherwise it will lead to instability of the system. In this paper, a detailed VSC HVDC model and a simple analytical technique using the principle of uniform loading to determine penetration limit is presented. The techniques is applied to our case study and validated with a simulation result. Critical contingencies such as sudden island conditions, threephase to ground fault are simulated with and without DC power penetration. Results show the stability support on the AC side networks by DC power injection on the dc-link.
2020
In this paper, strategies for a holistic integration of multiple HVDC links into existing power systems are presented. High Voltage Direct Current (HVDC) links can support the operation of AC grids on different timescales. Contrary to AC transmission lines, the power flow on HVDC links can be freely controlled. Due to their ability of rapidly controlling the power transmitted, they can help to stabilize the dynamic system response of interconnected power systems, e.g. providing fast frequency response. Moreover, they can be an important tool in controlling and in optimizing the operation of interconnected power system. In this paper, different strategies are presented, then their benefits and potential challenges are discussed. Keywords— High Voltage Direct Current (HVDC), Emergency Power Control, Frequency Containment Reserves, Lowand Zero-inertia, Electricity market, Loss Factors, Frequency Reserve Sharing
Hybrid HVDC system for multi-infeed applications
2013 International Conference on Emerging Trends in Communication, Control, Signal Processing and Computing Applications (C2SPCA), 2013
ABSTRACT The application of HVDC for stabilizing the large interconnected AC networks are resulting in several HVDC links inverting in the close electrical proximity. These multi-infeed HVDC system inverting into a weak AC network are of serious concern. One of the possible solution for better stability is using a VSC-HVDC as one of the infeed for the multi-infeed system. In this paper a multi-infeed HVDC system combining a conventional LCC-HVDC system and a Hybrid HVDC system consisting of LCC as the rectifier and VSC as the inverter is proposed for supplying a very weak AC network. The system performance during steady state and transient conditions is studied by simulation software PSCAD/EMTDC.
Dynamic Analysis of VSC-HVDC System with Disturbances in the Adjacent AC Networks
Distributed generation & alternative energy journal, 2023
VSC-HVDC systems are widely used to integrate wind farms, asynchronous generations and networks operating at different frequencies. The Multiterminal (MT) and multi-fed (MF) HVDC's are the system mainly constituted of VSC's, to integrate renewable sources and transmitting bulk power to conventional AC grids. A sudden change in the steady state even in adjacent networks may create severe disturbances in the operation of such HVDC systems. The disturbances in AC or DC networks directly influence the performance of systems, particularly in MT-HVDC and MF-HVDC systems. However, the HVDC systems are known for their intelligent control in modulating operational states as and when required. This paper presents the dynamic analysis of MF-HVDC system due to load changes, faults and other
A Study on an Operation Strategy of Dual-Infeed HVDC System
Journal of Electrical Engineering and Technology, 2017
This paper deals with the operation strategy of reactive power in a multi-infeed HVDC (MIHVDC) system, in which several converters are connected to the same or nearby separate AC buses. The potential problems concerning a MIHVDC system when feeding a weak AC network are as follows: the need for coordination of the recovery control, the possibility of voltage instability or low quality of the area connected to the MIHVDC system, and the risk of mutual commutation failures. These problems in MIHVDC systems are similar to those in single-infeed HVDC (SIHVDC) systems, but the differences with the phenomenon of the SIHVDC system are the interactions between converters. The main reason for the potential problems of HVDC systems (MIHVDC or SIHVDC) is voltage variation; therefore, to mitigate the voltage variations, the performances of the HVDC system should be enhanced. Consequently, to mitigate the potential problems of MIHVDC systems, several solutions are suggested in this study, including installing STATCOM and installing a line arrester on the tower. The study results will be applied to a multi-infeed HVDC system in Korea.
On the coordinated control of multiple HVDC links
… and Exposition: Latin America, 2008
Abstract-In this paper, coordinated control of multiple HVDC links in a small AC/DC power system is investigated. A coordinated control strategy is proposed to increase the transient stability and the damping in the AC/DC system. The system power loading is set by the well-known N - ...
Enhancing Power Transmission Stability with HVDC Systems During Load Contingencies
Journal Européen des Systèmes Automatisés, 2024
The transmission network of a power system is important in connecting interactions between the generation and distribution sides. A significant aspect in the power system profile is voltage improvement. This study intends to examine the impact of inserting High Voltage Direct Current (HVDC) on the system's voltage stability, network power losses and power transfer capacity of transmission network under several cases of load contingency. IEEE 57-Bus test system is used for testing the addition of HVDC transmission based on genetic algorithm. Modeling of point-to-point HVDC transmission and multi-terminal HVDC transmission is carried out using the Power System Simulator for Engineering (PSS/E) version 32 Package Program (A collection of computer programs and organized data files called PSS/E software was developed by Siemens PTI to handle the fundamental tasks of power system performance simulation work). The system's performance was compared with and without the HVDC inserted under different loading scenarios: 5%, 10%, and 20% of the total load. The comparative results can show that active power losses at the normal load case are reduced by 55.714% after inserting point to point HVDC topology, and after inserting multi-terminal HVDC topology reduced by 68.214%. Also, the reactive power losses reduce by 55.714% after inserting point to point HVDC topology and after inserting multi-terminal HVDC topology reduced by 66.830% at the same case. The results shown that inserting HVDC Transmission to the system gives better improvement in bus voltage profile and a significant reduction in total network power losses and increase in power transfer capacity of transmission network. The results also showed that multi-terminal HVDC transmission is better in voltage improvement and total power losses reduction when HVDC Transmission is added to the system.
Study of supplementary controls for embedded HVDC links in a AC power system
2008
This document reports a comprehensive study of supplementary control schemes for HVDC inter-ties parallel to AC transmission lines in order to reduce electromechanical inter-area oscillations employing a suitable two-area power system. The study includes design procedure and an extensive analysis based upon time domain detailed simulations, developed using PSCAD/EMTDC. Results obtained from two-area power system show how the control over the HVDC inter-tie effectively reduces the electromechanical inter-are oscillations. The supplementary outer control loop of the HVDC link, suitably designed, permits to increase the damping ratio of the system to a safe value, which can not be attained solely using power system stabilizers. Power modulation through the HVDC link effectively reduces electromechanical inter-area oscillations under a wide range of composite static load characteristics. Response is however limited by the value of the voltage index for active power; the compensation loop is functional only when this index is greater than one. The effectiveness of the supplementary control scheme is barely affected by the value of the voltage index for reactive power; these results reduce the modeling considerations of the reactive power characteristics, which in practical circumstances are more variable and depending on several and sometimes unknown factors.