The efficiency of overhead power lines can be increased by series compensation or HVDC transmission. These complex systems can be protected from overvoltages by metal oxide surge arresters. Both porcelain and polymer tube design surge arresters are used for these applications, however, polymer tube design surge arresters offer various advantages over porcelain arresters such as light weight, ex...

The design and stability assessment of a new robust nonlinear fuzzy controller that may be applied in the control loops of HVDC systems is presented. A new simplified nonlinear dynamic model is developed for HVDC systems that can be used to design the controller. The proposed model decomposes into several linear systems around important equilibrium points. These local linear models describe the...

The paper proposes a security-constrained optimal power flow algorithm (SC-OPF) which allows the post-contingency control of High Voltage Direct Current lines, based on the Voltage Source technology (VSC-HVDC). The presented algorithm integrates corrective actions of HVDC lines in a single optimization problem, without the need to solve a detailed power flow or OPF for each contingency. The app...

In this paper, a fuzzy logic controller is proposed for an application of HVDC link to stabilize the frequency oscillation in a parallel AC – DC interconnected power systems. When an interconnected AC power system is subjected to a load disturbance, system frequency may be considerably disturbed and becomes oscillatory. By utilizing the system interconnections as the control channels of HVDC li...

VSC-HVDC is a fully controllable transmission device, allowing rapid and independent control of active power transmitted over the dc link and reactive power at each end of the dc link. Embedding VSC-HVDC in meshed ac networks opens up new possibilities to improve power grid reliability and efficiency. The general control architecture of VSC-HVDC system is presented with focus on converter contr...

This paper investigates the use of multi-terminal HVDC systems to provide primary frequency support to connected AC networks via coordinated DC voltage manipulation. Control schemes for multi-terminal HVDC systems to allow redistribution of active power, based on the idea of “power priority” are proposed. Inertia response from DC connected large offshore wind farms can also be incorporated base...

This paper focuses on the engineering trade-offs in designing capacitor voltage balancing schemes for modular multilevel converters (MMC) HVDC: regulation performance and switching loss. MMC is driven by the on/off switch operation of numerous submodules and the key design concern is balancing submodule capacitor voltages minimizing switching transition among submodules because it represents th...

Bulk Power HVDC transmission schemes over distances of up to 2000 km are currently under planning for various large hydropower stations in India and China. Ultra high dc voltage (UHVDC) up to 800 kV is the preferred dc voltage level for these applications. Currently world-wide existing HVDC schemes are limited to maximum voltage levels of 500 kV to 600 kV. Therefore, the impact of increased ste...

To transfer large amount of direct current power having high amplitude voltage over long distance, high voltage direct current (HVDC) transmission system is used. This system was introduced 60 year ago and now it is widely used all over the world. Some examples of HVDC systems are following; Voltage-SourcedConverter (VSC), current commutated converter (CCC) and line commutated converter (LCC) d...

The DC-side line faults in high-voltage direct-current (HVDC) systems utilising voltage-source converters (VSCs) are a major concern for multi-terminal HVDC systems in which complete isolation of the faulted system is not a viable option. A number of challenges are posed by both pole-to-pole and pole-to-ground faults including the presence of very fast and high amplitude discharge current from ...