Features

Protection relay with IEC 61850

Key features:

• Compact plug-in design for easy handling  
• Large display with Single Line Diagram functionality
• 3 combi sensor inputs with conventional I/0 for analog measurement
• Native IEC 61850 support, including GOOSE and Process Bus
• Sensor support (Rogowski coils, Voltage dividers)
• Synchronism and energizing check function available with IEC 61850-9-2
• IEC 61850-8-1 GOOSE, horizontal binary communication
• IEC 61850-9-2 Sampled Values - Process Bus, horizontal analog communication

GOOSE: Generic Object Oriented Substation Event is communication that is used to broadcast events to peer protection relays in a substation via communication interface instead of hard wiring. GOOSE automatically supervises connections and can be modified without changing the wiring. Moreover, you do not need binary inputs and outputs to transfer data between protection relays and you can add functionalities and modify it without changing the wiring.

Process bus: IEC 61850-9-2 Process bus is communication that shares analog values over the Ethernet communication for protection purposes. One protection relay physically measures the analog value and shares it with other protection relays over the communication instead of hard wiring. Process bus brings several benefits to your application, such as simplicity, flexibility, improved diagnostics and longer maintenance cycles.

Current sensor

Key features:

• Large dynamic range, linear characteristic
• No saturation
• Small dimensions, light weight
• Negligible energy consumption
• Safe and error free connection to a protection relay
• Simplified engineering and logistics

Linear characteristic means that sensors are not affected by saturation and are able to measure accurately from very low primary currents up to very high short circuit currents. It is because they do not contain any iron core, therefore have highly linear characteristic. A linear and highly accurate sensor characteristic in the full operating range enables the combination of metering and protection class in one winding. 

Saturation of a current transformer is the state, when a current transformer containing iron core is not able to accurately transform the primary current waveform to the secondary side. The secondary current gets distorted, and is not able to represent actual primary current. This could lead to mal-operation of the protection relay, for example delayed operation or a false trip.

Secondary signal from a current sensor is a low level signal. In case of 50 Hz system, the secondary value is 150 mV at 80 A of primary current or in case of 60 Hz system, the secondary value is 180 mV at 80 A of primary current. Sensor secondary signals are at safe level for your operating personnel.

Sensors are equipped with a secondary cable for connection to a protection relay. Sensor cable type is a shielded cable with an industrial RJ-45 connector (CAT-6). Sensor technology prevents accidents caused by human errors. Practically, the secondary circuit of the current sensor can be left open with no risk of high voltage on the secondary terminals.

Voltage sensor

Key features:

• Large dynamic range
• Ferroresonance free
• Small dimensions, light weight
• Safe and error free connection to a protection relay 

Ferroresonance phenomenon is a typical, unpredictable network disturbance affecting voltage transformers. It appears usually in cable networks with an isolated neutral or not efficiently grounded systems. Due to the transient conditions (such as switching processes, failures or ground faults), the circuit might oscillate and exchange reactive energy within the oscillating circuit. Voltage transformer containing iron core represents inductive part of oscillating circuit. A permanent and high circulating current is then produced in primary winding which causes a lot of heat at the primary side of voltage transformer. This heat might result into voltage transformer explosion and damage on switchgear panel or even operating personnel. Additional equipment must be used to protect voltage transformers against this phenomena, such as smart devices (ABB‘s VT Guard Pro) or dumping resistor. Voltage sensors represent ferroresonance free solution, due to absence of any iron core, therefore there is no need to use any additional equipment.

Secondary signal from a current sensor is a low level signal. In case of 50 Hz system, the secondary value is 150 mV at 80 A of primary current or in case of 60 Hz system, the secondary value is 180 mV at 80 A of primary current. Sensor secondary signals are at safe level for your operating personnel.

Sensors are equipped with a secondary cable for connection to a protection relay. Sensor cable type is a shielded cable with an industrial RJ-45 connector (CAT-6). Sensor technology prevents accidents caused by human errors. Practically, the secondary circuit of the current sensor can be left open with no risk of high voltage on the secondary terminals.

Condition monitoring and diagnostics

Key features:

• Online monitoring locally on the panel level for temperature rise in critical joints on primary circuits, breaker characteristics, and partial discharge 
• On-premise solution for the health indication and diagnosis of the switchgear lineup – SWICOM (Web page)/CMES (Web page)
• Cloud application for asset health management able to cover the complete plant – MyRemoteCare (Web page) 

Temperature rise indicate the quality of primary connections within the panel, such as busbar connections, circuit breaker connections and cable connections. Online monitoring of temperature rise provides a reliable way to identify such risks with proper alert.
Condition of breaker over long lifetime is continuously monitored through every run-time open or close operation, much more accurate than offline testing. Throughout the dedicated diagnosis, alarms as well as electrical wearing can be estimated, to deduce the next maintenance properly.

Insulation performance is the most critical aspect when designing switchgear. Due to complicate or harsh environment, insulation can be subject to accelerated ageing. The online monitoring of partial discharge provides an effective manner to capture such deterioration of insulation as earlier as possible to avoid disruptive failures.