Accelerating VPR and VPAC tools development with Kalkitech’s IEC61850 based Framework

Kalkitech has created a set of “reference” protection applications to pair with VPR server hardware, hypervisors, and other components to build a complete VPR system that serves multiple roles in market adoption: as a proof of concept, a demonstration system, and a tool to help the industry evaluate the capabilities, tradeoffs, and challenges posed by the VPR architectural options.

A key objective is to demonstrate that multiple protection relays can function in a virtualized environment, meeting or even exceeding the performance and time requirements of modern protection IEDs, while adding redundancy, resiliency, ease of deployment, and many other features.

IEC 61850 development framework

The VPR reference application is built on an IEC 61850-based Virtual Protection Relay (VPR) framework designed by Kalkitech. The solution enables utilities and OEMs to validate the platform architecture, extend capabilities, analyze performance, and integrate with other applications. Thus, by providing a flexible and scalable platform, the VPR framework helps organizations evaluate and enhance their protection systems while adhering to IEC 61850 standards.

Figure 1 : Kalkitech IEC 61850 VPR Framework with ready-to-use IEC 61850 libraries and APIs.

Kalkitech VPR Framework has the following components:

• IEC 61850 Components
• IEC 61850-9-2 Sampled Value Subscriber.
• IEC 61860 8-1 Server module implementing MMS Server and GOOSE Subscriber/Publisher.
• IEC61850 SCL Configuration for VPR.
• Signal Conditioning Module
• Reference Protection Functions for evaluation.
• Disturbance Recorder
• VPR APIs

The key components of IEC 61850 server implementation include Logical Nodes (LNs), which represent functional units like circuit breakers or protection relays, and Data Objects (DOs), which define specific attributes or properties of these devices. The server also facilitates various services for client-server communication, including reading/writing data, control commands, and event reporting, enabling real-time monitoring, protection, and control in substations.

The Substation Configuration Language (SCL) is used to configure and describe the substation's system and communication topology. Communication relies on Ethernet-based protocols like MMS (Manufacturing Message Specification), GOOSE (Generic Object-Oriented Substation Event), and SV (Sampled Values) for real-time data exchange. The GOOSE Publisher is responsible for sending GOOSE messages containing status updates, alarms, or events, typically in a substation or power grid environment.

The Sample Value Subscriber receives the Sample Value stream, which is then processed by the Conditioning Module and exchanged with the Protection Functions.

Reference protection functions available for evaluation include Distance Protection (21), Transformer Differential Protection (87T), Time-Delayed Phase Overcurrent Protection (51), Time-Delayed Derived Neutral Overcurrent Protection (51N), Instantaneous Phase Overcurrent Protection (50), Instantaneous Derived Neutral Overcurrent Protection (50N), and Breaker Failure Protection (50BF).

Protection function developers or vendors can integrate the modules using the VPR API library provided by the framework. The term “Vendor X and Y” in the figure refers to areas where domain experts and developers from multiple companies can insert their conditioning and protection function components. A Disturbance Recorder module is also implemented, which saves the data in COMTRADE format. The configuration module has been developed specifically for configuring protection function parameters.

Kalkitech VPR Architecture

Figure 2 : Virtual Protection Relay reference application.

The Current Transformers (CT) and Potential Transformers (PT) measure electrical parameters such as current and voltage from the power system. The Merging Unit (MU) converts the analog data into digital format, and the sampled data is transmitted over the Process Bus to both the VPR node and the station bus. This enables data exchange using MMS (Manufacturing Message Specification) for configuration and access, and GOOSE (Generic Object-Oriented Substation Event) messages for fast, real-time event notifications, such as fault detection and breaker tripping. The system also includes software components for configuring and monitoring the protection system, including Human Machine Interfaces (HMI) and a disturbance recorder (DR) that stores event data in formats like COMTRADE. Additionally, the VPR can be integrated with the utility’s Supervisory Control and Data Acquisition (SCADA) system for centralized monitoring and control.

Evaluation of VPR

When evaluating a Virtual Protection Relay (VPR), several technical considerations are critical to ensure optimal performance. These include latency, throughput, scalability, redundancy, failover mechanisms, and self-healing capabilities to ensure system reliability and zero downtime. Security is essential for protecting against cyber threats, while modularity and extensibility ensure seamless integration with existing systems and accommodate future enhancements.

The VPR should support scalability as system complexity grows and maintain consistent performance. Protection functions, such as overcurrent, undervoltage, differential, and distance protection, must comply with industry standards and IEC 61850, particularly in a virtualized environment.

Performance testing involves critical tests like the Cyclic Test and GOOSE Ping-Pong test to evaluate network latency. Additionally, assessing the network interface card (NIC) performance is essential to prevent packet loss or jitter when handling sampled value (SV) streams. Server, VM, and hypervisor optimization, including real-time priority, CPU pinning, and hyperthreading, also play a significant role in performance evaluation. These tests ensure the VPR system can function reliably in real-time conditions, handle various network and system configurations, and meet the performance needs of protection functions in a virtualized environment.

We can expect to see increased adoption of VPR systems in substations, which will likely improve real-time performance, reduce costs, and ensure resilient grid operation. Ongoing development and evaluation of VPR, subjected to rigorous performance testing, will be instrumental in paving the way for a more intelligent and adaptable power grid.