Impact of low (zero) carbon power systems on power system protection: a new evaluation approach based on a flexible modelling and hardware testing platform

Abstract

This paper presents a flexible model and testing arrangement that can be used to mimic the fault infeed characteristics of power electronics converters and evaluate the performance of transmission protection schemes to faults when the system is "converter-dominated". That is, sources (e.g. renewables) and infeeds (e.g. HVDC interconnectors) that are interfaced to the main power system via converters. Actual protection relays are injected, in real time, using the outputs of the various fault simulations. A range of potential protection issues, including slow tripping, erroneous discrimination and non-operation, are illustrated for particular scenarios. The main contributions of the paper include knowledge of how different protection schemes may be affected by converter-interfaced sources and guidance on possible solutions to the observed problems. Two solution options are highlighted: changes to the fault detection methods used within relays, and/or defining the fault-response elements of future grid codes (and therefore future converter fault responses) to ensure that existing protection schemes will not be adversely affected in future low-carbon, converter-dominated systems.

A q component‐based adaptive protection coordination optimisation using overcurrent relays in coordination with fuses for hybrid microgrid

“…Also, the q component-based PCO is fast in comparison with [10]. In comparison to [21,[30][31][32][33], the proposed scheme is equally effective with the proposed reduced number of variables. The efficiency and accuracy of the relay settings can be examined by observing the primary relay operational time and CTI during faulty conditions.…”

A Flexible Real Time Network Model for Evaluating HVDC Systems' Impact on Ac Protection Performance

“…Where 𝑣 and 𝑖 are the three-phase voltage and current and 𝑣 ⊥ is the orthogonal version of the original grid voltage vector 𝑣. Considering the positive and negative sequence components, the (1) and ( 2) can be extended as ( 3) and (4).…”

“…In existing technical literature, there are a number of network models reported for testing the distance relay performance. In [3] [4], the impact of the converter-interfaced units, including the HVDC system and NSG, on the distance relay performance is reviewed, but the models included in these papers do not allow the investigation of the influence of different HVDC control strategies and synchronous compensation. A relatively flexible network is implemented in [5], where the controller in [6] is used for the design of the HVDC system.…”

Guest Editorial: Challenges in Future Grid‐Interactive Power Converters: ControlStrategies, Optimal Operation, and Corrective Actions

“…For wider system operation, operation and control, paper [23] presents a power electronic dominated grid mode and thoroughly studies the triggering impact of different converter penetration levels on transmission grid distance protection. Paper [24] reports an energy router control scheme for smart communities to enable grid‐connected, stand‐alone and transition modes.…”