Brochure · EN — Siemens Energy Transmission Service brochure (2021) for Assetguard HVC, a condition monitoring system for AIS and GIS switching devices (circuit breakers, disconnectors, earthing switches). A base unit with all components in a single housing monitors interrupted fault currents, switching times, coil current waveforms, motor drive current, insulation gas density and pole travel, assesses each switching operation against preconfigured thresholds, and reports alarms via an integrated web server, hard-wired contacts and IEC 60870-5-104 / IEC 61850 ed.2 SCADA protocols — supporting condition-based maintenance and life extension of HV switchgear.
The reliability of HV switching devices (circuit breakers, disconnectors, earthing switches) is generally high. However, due to lifetime extension and changed maintenance policies, additional care should be taken to maintain an acceptable reliability level. This is a challenge when the components are exposed to severe environmental conditions or in case of an increased number of operations. Moreover, mechanical parts of switching devices not operated continuously may not work properly due to dirt and contaminants.
Assetguard HVC is a condition monitoring system for AIS and GIS switching devices. The system has a distributed structure in which a base unit monitors specific signals and acts as communication master of a riser network. Remote auxiliary units (optional) are available for specific measurement purposes.
The main monitored parameters are interrupted fault currents, switching times, current waveform of the coils, motor drives absorbed current, insulation gas density and mechanical movement of poles thanks to a dedicated encoder connected to the pole position indicator. In this way, Assetguard HVC is able to constantly monitor tripping and closing functionalities and main contact wear.
The main features of Assetguard HVC are: transmission of alarms in case of anomalies, warnings if the switchgear is losing functionalities, and information in case maintenance is needed; all components integrated in a single housing (power supply, data acquisition, fiber optic communication, data storage and a web server); predefined or customized measuring kits supplied for installation in each circuit breaker cabinet; a combined hardware and digital filter for better noise immunity performance; and available communication protocols for integration into SCADA — IEC 60870-5-104 and IEC 61850 ed.2.
Assetguard HVC supports circuit breakers to overreach their assigned technical life, reduces the risk of consequential damages and the probability of unexpected outages, and avoids intensive periodical and manual measurements. Safe operation of the monitoring system is guaranteed thanks to no changes in protection wiring.
It supports condition-based maintenance with instant diagnosis and data collection for condition assessments. It is a cost-effective solution with low installation costs and suitable solutions for retrofit and self-installation, backed by professionals with many years of experience and qualifications in the utility and infrastructure industries.
Each Assetguard HVC comprises: external sensors (e.g. current transducer, current transducer hall effect); optional external sensors on request (e.g. for measurement of humidity or temperature and for SF6 gas monitoring, travel curve encoder); turnkey installation and communications services; expert analysis of monitoring data and customer support; on-site trainings for operation and maintenance; and the design, installation and commissioning of all necessary equipment.
The hardware is shown in the brochure in two form factors: a 19" full rack version and a half rack version.
At each incoming switching command, a measurement is started. The measurement ends when the switching operation has been completed. Data are recorded internally in the memory of the Assetguard HVC node unit. Switchgear functionality is assessed by comparing recorded data with preconfigured thresholds. Any alarm is communicated via the integrated webserver, hard-wired contacts and using the integrated protocols.
A Main Data Unit (MDU) with dedicated knowledge modules is used to detect any defects in coil behavior, to suggest maintenance needs in the mechanical drive or to evaluate contact wear (Arcing I2t). Assetguard HVC also guarantees the monitoring of the auxiliary circuit voltage, the closing coil and the tripping coil currents by means of high-resolution waveforms.
The main data unit is also able to acquire and assess the motion travel curve of the poles during operations, and performs further calculations on opening operations (current summation interrupted and counter number of operations).
In detail, the following measurements are acquired (verbatim from the brochure's bullet list, reformatted as a table):
| Measurement | Detail |
|---|---|
| Operating times | Operating times of individual poles during opening and closing in tenths of a millisecond (Open / Close single, CO, O - CO) |
| Fault current | Peak fault current during opening in kA tenths |
| SF6 gas density / temperature per switch/pole | Continuous monitoring of the density value or pressure compensated in temperature @20°; detection of gas leaks with indication of the remaining time at the appearance of the first alarm |
| Current absorbed by charge-spring motors or pumps | Number of daily starts and total hours of operation; steady state current consumption; threshold for maximum current absorbed when fully operational |
| Coil currents | Curves of the currents absorbed by the opening and closing coils during operation performed |
| Optional | Data from travel curve encoder, disconnectors and earthing switch and additional input channels |
Assetguard HVC is designed to withstand the harsh electrical, mechanical and environmental conditions of a substation, while providing the necessary hardware and software for a comprehensive monitoring device. The ratings below are verbatim from the brochure's Technical data bullet list, reformatted as a table.
| Characteristic | Specification |
|---|---|
| Electrical safety | According to EN 60529, EN 61010-1 and EN 60255-5 |
| Dielectric withstand | Power supply port and each channel: 3 kV RMS for 60 s and 5 kV 1.2/50 µs impulse |
| Electromagnetic compatibility (EMC) | According to EN61000 and EN 55011: Level 3 electrostatic and electromagnetic immunity; 4 kV surge immunity |
| Environmental strength | According to EN 60068: operating temperature -30°C to 70°C; humidity 10 - 95% |
| Protection class | IP 20 |
| Measurement resolution | 12 bit at 10 kS/s (16-bit version available upon request) |
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