Intelligent system for detecting "hidden" errors in protection settings

Due to many developments taking place within the electricity supply industry, the network and its operation has grown ever more in recent years, which brings significant challenges for power system protection engineers. Apart from the significant efforts that are required to ensure that the protection setting process is effective, work also needs to be carried out to check the validity of the settings after initial calculation and application. However, solely relying on personnel and procedures to assess the validity of the protection relay setting files may occasionally result in a hidden error (or errors) remaining undetected until an in-service mal-operation event is experienced. This may bring significant consequences, in terms of economic costs, potential safety hazards and damage to the reputation of the utility company. This paper will present the initial research of making use of artificial intelligence technology (expert system) to help protection engineers validate the protection settings. Existing expert systems for protection settings applications will be reviewed and a new intelligent system that can open a setting file and interrogate the protection functions and settings in the file will be introduced. The advantages of this novel intelligent tool over existing protection setting expert systems will be discussed

Deployment of synchronous compensators in the GB transmission network to address challenges from increasing renewable generation

This work proposes to investigate the benefits of synchronous compensation in addressing concerns pertinent to: • the quantitative study of the benefits of synchronous compensation to system rate of change of frequency (RoCoF); • the quantitative study of the impact that synchronous compensation has on the risk of loss of commutation on the Western Link

Enhanced frequency control capability (EFCC) project

EFCC aims at developing and demonstrating a wide area monitoring and control scheme that is capable of deploying fast and coordinated frequency response using a variety of resources such as PV, energy storage, wind farms, demand side resources (DSR), and CCGTs. The successful implementation of this project is expected to enable faster response than existing schemes and lead to savings of £150m-£200m per annum by 2020

Translating proprietary protection setting data into standardized IEC 61850 format for protection setting validation

For smart grid development, one of the key expectations is that the data should be accessible to and readily interpreted by different applications. Presently, protection settings are represented using proprietary parameters and stored in various file formats. This makes it very difficult for computer applications to manipulate such data directly. This paper introduces a process that translates the proprietary protection setting data into IEC 61850 standardised format and saves the data as System Configuration description Language (SCL) files. A code generation process that allows rapid implementation of the translation process is proposed. Among various applications, the paper demonstrates how such a translation process and generated SCL files can facilitate the development of an intelligent system for protection setting error detection and validation

Standardization of power system protection settings using IEC 61850 for improved interoperability

One of the potential benefits of smart grid development is that data becomes more open and available for use by multiple applications. Many existing protection relays use proprietary formats for storing protection settings. This paper proposes to apply the IEC 61850 data model and System Configuration description Language (SCL), which are formally defined, to represent protection settings. Protection setting files in proprietary formats are parsed using rule-based reasoning, mapped to the IEC 61850 data model, and exported as SCL files. An important application of using SCL-based protection setting files is to achieve protection setting interoperability, which could bring multiple compelling benefits, such as significantly streamlining the IED configuration process and releasing utilities from being “locked in” to one particular vendor. For this purpose, this paper proposes a uniform configuration process for future IEDs. The challenges involved in the implementation of the proposed approach are discussed and possible solutions are presented

Application of a MW-scale motor-generator set to establish power-hardware-in-the-loop capability

This paper presents a Power-Hardware-in-the-Loop (P-HiL) testbed coupled to a MW-scale Motor-Generator (MG) set. The P-HiL configuration interfaces an 11 kV physical distribution network with a transmission network modeled in a Real Time Digital Simulator (RTDS) through the MG set. Uniquely, and in contrast with other P-HiL arrangements, the MG set used is equipped with a proprietary frequency controller with an inherent response that does not provide the desired characteristics to cater for a P-HiL interface. The paper describes a methodology to tackle this problem associated with undesirable response of the MG set’s existing controller by introducing additional frequency and phase control loops. Experimental results are presented and show that the P-HiL testbed is capable of maintaining a high level of synchronization during disturbances and allows the power interaction between the model and physical network. The testbed offers a realistic and flexible testing environment for prototype systems connected to distribution networks with a specific focus on testing systems that control demand side resources for frequency response during loss of generation events

Wide-area backup protection and protection performance analysis scheme using PMU data

This paper presents a wide-area backup protection scheme that incorporates protection performance analysis based solely on voltage from Phasor Measurement Units (PMUs). The system reports and summarizes information relating to fault detection, and identification of the faulted circuit(s) protection/circuit breaker operation (i.e. whether it is correct or not), in a short period of time. It can also be applied as an effective and relatively simple, fast, wide-area backup protection to improve the resilience of power systems. Case studies are presented, where the proposed wide-area backup protection scheme is validated using the IEEE 14-bus network. It is demonstrated that the proposed scheme is capable of correctly detecting faults (including high-resistance faults) in less than 100 ms from fault inception and can report on whether the protection/circuit breakers have operated as expected within a further 100 ms, thereby coordinating with existing protection systems with a view to enhancing the system reliability and security by appending existing protection systems with system-wide information. Applicability of the developed system to large-scale power systems is also demonstrated. Discussion relating to how this method can be cost effective through exploitation of existing PMU data, which may already be used for other purposes, is included

Validation of algorithms to estimate distribution network characteristics using power-hardware-in-the-loop configuration

Distribution system operators (DSOs) require accurate knowledge of the status of the network in order to ensure the continuity and quality of power supply. In this context, the National Physical Laboratory (NPL) and the Power Network Demonstrations Centre (PNDC) have been working together in the development and validation of optimal sensor placement and network topology estimation algorithms. This paper presents the description of two of these algorithms as well as the topology configuration of the PNDC distribution network considered to gather measurements for the validation of the algorithms. A Power-Hardware-in-the-Loop (P-HiL) configuration has been used as the testbed, where a number of physical measurement devices are installed in the physical network and an extended number of devices are virtually installed in the simulate network. The applications of the proposed algorithms to the measurements along with results from the P-HiL tests are presented in the paper

Analysis and simulation of current-only directional protection incorporating simple communications

This paper presents a review of a range of novel protection schemes and described a new fault detection method using only current measurements, based upon comparison of pre- and during-fault current angles (and communication of angular shifts between measurement locations when faults are detected). Case studies are also presented to validate the effectiveness of the proposed method. The scheme is suitable for when conventional protection is not suitable for power networks, particularly microgrid with distributed generation units and energy storage leading to bi-directional power flows during normal and fault conditions, and low- and variable fault levels. In such cases, directional relays may be necessary to provide effective protection. However, measuring both voltage and current may be expensive and the scheme highlighted here overcomes such requirements, and it is proposed that 4/5G communications or radio-based communications may provide an effective means of transferring the (low-bandwidth) data when required

A model-based approach for automatic validation of protection settings

The reliable operation of protection systems depends on the correct setting of protective devices. Due to the increasing network complexity and the large number of protective devices (and their associated setting parameters), it is extremely laborious for engineers to manually validate the settings. Existing model-based (MB) systems that are capable of performing the validation task require significant manual input for network models creation, relay models configuration, simulation result analysis, etc., which is both time consuming and subject to human errors. This paper presents a methodology that adopts the principle of model-based reasoning (MBR) for automated validation of protection settings. Such a methodology is demonstrated through the design and implementation of a prototype tool Model-Based protection setting Smart Tool (MBST), which is capable of automatically populating network models, configuring relay models with settings to be validated, creating credible system events, and simulating the relays’ behaviour under these events. The automated process is achieved by an interface layer within MBST that allows interaction with a commercially available simulation engine to leverage its internal data and functions for the settings validation task. The simulated results are automatically analysed using a rule-based (RB) approach. The key advantage of the work is the mechanism to automate the entire settings validation process. The design of the interface layer to interact with existing simulation engine and models also demonstrates a solution for rapid prototyping of intelligent systems dedicated to validation of protection settings