In modern industrial systems, including power system automation, it is important to ensure that new standards are able to communicate with the older ones. IEC 61850 standard has been gaining significant ground in power system automation due to it is object-oriented design. In line with its exponential growth, it is imperative to integrate IEC 61850 with other information exchange approaches. Modbus is a very robust communication protocol that uses registers. Since it can be deployed in a cost-effective way, it is widely used in older or lower-cost devices. Unlike IEC 61850, which supports real-time communication, Modbus envisions a trigger-based communication style. All of these fundamental differences make direct communication between these two protocols nontrivial. In order to address this need, IEC TR 61850-80-5 is developed to give a structured approach for mapping Modbus data into the IEC 61850 data model. This is conducted using a gateway and includes identifying relevant Modbus registers, converting the data format and embedding them into IEC 61850 logical nodes and data attributes. If completed, this allows legacy devices such as meters or sensors running on Modbus to be seamlessly integrated into modern smart-grid systems using IEC 61850. This paper shows how such integration can be performed between smart inverters and the sensors feeding information to them. Firstly, both protocols are introduced. Then, the IEC 618150 modeling of smart inverters is presented. Finally, data mapping is performed between Modbus registers of current- and voltage sensors and the said smart inverter model. A gateway is developed based on this mapping as well. By bridging two widely used protocols, this work supports interoperability, extends the life of existing assets and ensures a smooth transition towards digital power systems.
Taha Selim Ustun (Mon,) studied this question.