IEC 61850 GOOSE

The predecessor to GOOSE, GSSE provides a fixed-format, high-speed peer-to-peer communication mechanism for transmitting binary status data between IEDs. Unlike GOOSE, GSSE uses a rigid data structure that cannot be customized, limiting its flexibility. GSSE messages are mapped directly to ISO/IEC 8802-3 (Ethernet) frames and use multicast addressing. While still supported for backward compatibility, GSSE has been largely superseded by GOOSE in modern substation designs due to GOOSE's support for configurable datasets and extended data types.

A companion protocol to GOOSE within IEC 61850 that transmits digitized current and voltage measurements from merging units to protection relays at high sampling rates—typically 80 samples per cycle for protection applications (4 kHz at 50 Hz). Unlike GOOSE's event-driven model, SV uses a continuous, time-synchronized streaming model. SV frames are multicast over Ethernet using IEEE 802.1Q VLAN tagging for priority queuing. The combination of GOOSE for binary signals and SV for analog measurements enables a fully digital substation where copper wiring is replaced by fiber-optic Ethernet.

The client-server communication protocol within IEC 61850 used for supervisory control and data access, as opposed to GOOSE's peer-to-peer model. MMS operates over TCP/IP and enables SCADA systems to read measurements, control switchgear, and upload disturbance recordings from IEDs. Key services include: - GetDataValues: Poll current status - SetDataValues: Issue control commands - Reporting: Buffered and unbuffered event reporting MMS provides the vertical communication path, while GOOSE handles the horizontal, time-critical protection signaling between bay-level devices.

An XML-based language defined in IEC 61850-6 that describes the complete substation automation system, including the primary equipment, communication network topology, and IED capabilities. SCL file types include: - SSD: System Specification Description - ICD: IED Capability Description - SCD: Substation Configuration Description - CID: Configured IED Description The SCD file binds GOOSE publishers to subscribers by defining which IEDs transmit specific datasets and which IEDs are configured to receive them, enabling automated engineering workflows.

A microprocessor-based controller that implements one or more protection, control, or monitoring functions within a substation. In the GOOSE context, an IED acts as either a publisher (transmitting status changes) or a subscriber (receiving and acting on GOOSE messages). Modern IEDs support hundreds of virtual GOOSE inputs and outputs, replacing physical copper wiring between devices. Each IED is identified by a unique IED Name within the SCL configuration, and its GOOSE capabilities are declared in the device's ICD file.

A time synchronization protocol that provides sub-microsecond accuracy across Ethernet networks, essential for aligning Sampled Values from multiple merging units and timestamping GOOSE events. PTP operates through a master-slave hierarchy where a Grandmaster Clock distributes time using hardware timestamping at the Ethernet physical layer. IEC 61850-9-3 specifies the PTP profile for power utility automation, achieving accuracies better than 1 microsecond over 16 network hops. This precise time alignment enables differential protection schemes that compare synchronized current measurements from opposite ends of a transmission line.