Digital switchgear

ES GEAR is a technology for creating digital switchboards of middle voltage. ES GEAR switchboard consists of digital cells, interconnected by substation bus. The main components of the cell are connected to each other by "digit" – by means of the protected low-level process bus. Digital connections between devices inside the cell minimize the number of terminals and wires, simplify installation, speed up cell testing and put the entire distribution plant into operation. Complete diagnosability of electrical components is an important advantage for operation.

ES GEAR includes digital combined current and voltage sensors (DSCV), an intelligent switch under the control of a specialized controller (ENCB) and relay protective device (ENBC). All listed components are connected to each other by low-level deterministic bus of the FlexRay process. The low-level process bus has fault-resistant communication redundancy mechanisms, operates in hard real time, and provides device time synchronization. In addition, ES GEAR is equipped with a multifunctional measuring device (ESM-SV), arc sensors (AFS), temperature sensors (ITS) and information display panel (ENBC Touch).

DSCV provides phase-measurement of currents and voltages. Digitized current and voltage values are published to the FlexRay bus and to ESM-SV via Ethernet.

DSCV and ESM-SV are measuring instruments. When released, these devices undergo primary verification, but in the future, periodic verification is recommended only for DSCV, since the metrological characteristics of digital measuring instruments (more correctly called computers) such as ESM-SV do not change over time.

ENBC implements a typical set of relay protection and automation functions of the switchgear cell. ESM-SV is used for electricity metering, grid mode parameters’ calculation and power quality control.

In addition to the monitoring and control functions of the switch, ENBC provides backup protection for the shutdown of the switch in case of the accident, even if all other components of the digital cell fail.

The ES GEAR implements the following functions:

Functions LN Description
System Logical Nodes LLN0 Logical node zero
LPHD Physical device information
Protection functions PTOC Time overcurrent
PDOC Directional overcurrent – in developing
PTUV Undervoltage – in developing
PTOV Overvoltage – in developing
PTRC Protection trip conditioning
Protection related functions RBRF Breaker failure
RREC Autoreclosing
RDRE Disturbance recorder function
RADR Disturbance recorder channel analogue
RBDR Disturbance recorder channel binary
Сontrol CSWI Switch controller
CILO Interlocking
Generic references GGIO1 Generic process I/O (DI/DO/AI)
Metering and measurement MMXU Measurement
MMTR Metering
MSQI Sequence and imbalance
Switchgear XSWI Circuit switch
XCBR Circuit breaker
Instrument transformers TCTR Current transformer
TVTR Voltage transformer

At the moment, within the development of ES GEAR functionality, algorithms for fast bus protections and connections are being developed with the use of PMU technology: thanks to the exchange of synchronizers and GOOSE messages at the substation, it is possible to distribute data processing between the protections of individual connections and implement protection with absolute selectivity. 

ES-GEARs are connected by substation bus using parallel seamless protection according to IEC 62436-3 (PRP). Similarly, or by RSTP, ESM-SV are combined. Time synchronization of ESM-SV and ENBC is carried out via SNTP protocols, PTPv2. Operating staff can monitor parameters and control ES GEAR through the single ENBC-Touch information panel, which is connected to ENBC controller and ESM-SV by RS-485.