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

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

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

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

Improved protection system for phase faults on marine vessels based on ratio between negative-sequence and positive-sequence of the fault current

This paper presents a new method to protect the radial feeders on marine vessels. The proposed protection method is effective against Phase-Phase (PP) faults and is based on evaluation of the ratio between the negative-sequence and positive-sequence of the fault currents. It is shown that the magnitude of the introduced ratio increases significantly during the PP fault, hence indicating the fault presence in an electric network. In this paper, the theoretical background of the new method of protection is firstly discussed, based on which the new protection algorithm is described afterwards. The proposed algorithm is implemented in a programmable digital relay embedded in a Hardware-in-the-Loop (HIL) test setup that emulates a typical maritime feeder using a Real Time Digital Simulator (RTDS). The HIL setup allows testing of the new protection method under a wide range of faults and network conditions and the experimental results demonstrate its effectiveness in all scenarios conducted. The proposed protection method offers a solution to the protection challenges associated with variability of the short-circuit currents in radial feeders, advancing in this way the traditional mean of protection in maritime feeders, represented by OverCurrent (OC) relays

Enabling efficient engineering processes and automated analysis for power protection systems

The reliable operation of power networks depends on the correct configuration of protection systems. These systems involve the coordination of devices across a wide area, each with numerous setting parameters. Presently, protection settings data are typically stored in various vendor-specific proprietary formats, which are difficult to access, interchange, and manipulate automatically. Consequently, the engineering processes for implementing modern protection systems are extremely complex, involving multiple software tools from different vendors. This paper presents a novel solution to these challenges, through the use of the data model provided by the IEC 61850 standard, with the System Configuration description Language (SCL) format to represent protection settings data. The design of a Protection Setting data Conversion Tool (PSCT) that can automatically convert existing settings data between proprietary formats and the SCL-based format is presented. A case study of its implementation demonstrates the benefits of the common representation of protection settings for network operators and other stakeholders. The paper also addresses the challenges that network operators face in migrating to the new approach from existing legacy protection devices and data formats. Adoption of these recommendations and design approaches would shift protection systems from being largely single-vendor solutions to becoming efficient and truly open platforms, capable of supporting future intelligent applications and tools such as automated protection settings validation, diagnostics, and system simulation

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

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