BSC-50D Αρχεία - Infinite Informatics

Earth Fault Monitoring for Power Grids

pratos@indinf.gr — Wed, 02 Dec 2020 23:15:14 +0000

Introduction

This presentation is dedicated for Earth Fault Monitoring for Power Grids .

Autonomous RTUs: BSC-50D, BSC-50E, ADS-260 SIGFOX, ADS-410.

Read the complete application presentation at,

Earth Fault Monitoring EFD v5.pdf

Το άρθρο Earth Fault Monitoring for Power Grids εμφανίστηκε πρώτα στο Infinite Informatics.

Earth fault monitoring in medium voltage substations

it@mms-adv.gr — Wed, 04 Nov 2020 09:00:36 +0000

Introduction

Medium voltage substations require monitoring in order to help power grid operators re-establish power, when network faults occur. Identifying a substation that is out of power is time critical to minimize operations to link back power on the grid.
Modern substations are equipped with earth fault detection relays (EFI or GFI, Earth or Ground Fault Indicator), which provide a digital contact when a line fault occurs. The goal is to reduce drastically the outage time. The normal procedure when a fault is detected is to send maintenance crew to visit a series of substations, identify the stations, which have a fault status and report this back to the control center. Then operations to reroute power are made remotely or on a trial and error basis, which damages the network infrastructure.

Requirements

Identify faults almost online and alert via SMS to a control center.
Minimize needed power rerouting operations.
Identify operational faults from substation equipment.
Manual operations alarming.
Intruder security alarming.

Proposal

BSC-50E and BSC-50D battery powered RTUs are ideal for alerting using SMS. The proposed system consists of:

Special fault detection relays that detect ground fault and provide a plain contact as an alert in the event of a fault.
BSC-50D or BSC-50E devices which are installed to monitor the alarm state on medium voltage substations.

When an earth fault is detected in a substation the result is that the substation is automatically taken off the power grid. Manual or remote operations are needed to place the substation back on the grid. The BSC-50 devices monitor earth faults and transmit respective coded messages via SMS to a control center. Moreover BSC-50 RTUs can be configured to transmit a health message in a scheduled manner to the control center to ensure their operational status.
At the control center a PC running 24/7 software, logs alerts, monitors and reports the operational status of the BSC50 devices. Integration to existing SCADA systems or GIS applications is seamless via an OPC server.

M2M solution

Furthermore, as an extension utilizing M2M functionality, SCOM-100 devices can be used at the control center in order to have an unmanned system. In this case, at the control center, a mimic diagram showing the geographic location of the substations and BSC-50 devices is installed. The mimic diagram has built in colored LED at each substation. The LEDs are cabled to an M2M (machine to machine) alert receiver device as an SCOM-100 unit. The LEDs are connected to digital outputs on the SCOM-100. When an alarm occurs at a BSC-50, two messages are send, one at the control center monitoring station running the monitoring SW and one to the SCOM-100 device switching a LED at the mimic diagram.If the fault is rectified, the LED can be switched off via a manual operation of a switch on the mimic diagram (alarm acknowledgement and rectification). In this way users at the control center can,

Visualize the location of the line faults.
Trace the sequence of failing substations.
Perform remote switching operations (if this is possible in respect to a local substation automation), or to order maintenance crew to visit a specific point on the grid to reroute power and maintain power in the areas which had been taken off the grid.

For example a BSC-50D alerting instantly and sending a health message every week, will operate on one Lithium Thionyl D type battery for more than 12 years.

Why BSC-50

All-in-one cellular GPRS quad band solution
Ultra low power, can run for years on one D type battery
Real-time alerting
Easy to implement and maintain
Seamless connection to SCADA via OPC server
SMS alerts and M2M functionality

Autonomous intrusion alarming via SMS

it@mms-adv.gr — Wed, 07 Oct 2020 07:54:27 +0000

Introduction

An electrician wrote on the Electricians & Electrical Forum, UK:

“URGENT HELP NEEDED!!
I have a client here in France who has a house in a remote location. The house has been broken into three times this year and I have been asked to install a GSM alarm with no outside or internal sounder, due to the fact that the last alarm system was just smashed off the wall. What I actually need is a lithium powered wireless alarm with a telephone dialler as the house it is to protect is remote and left unoccupied for long periods of time. The other problem is that the house does not have mains electricity, but a rather complex generator/battery set up which has been known not to auto-start.”

Indeed, where no mains power is available, classical alarm systems are not applicable. This is commonly the case in off grid military depots, private boats, holiday homes, builder sheds, farm sheds, aircraft hangars, etc.
There are also cases where mains powered alarm systems fail to operate after a power blackout, due to a backup battery failure or a disturbance caused by the outage.
Infinite’s autonomous RTUs, combined with new technology, ultra low power PIR sensors, offer highly reliable solutions in security. An SMS alarming system, consisting of a BSC-50D RTU and a low power PIR sensor for motion detection, can operate for over 10 years, powered only by one Lithium D-size battery!

Proposal

AERINOS^TM BSC-50D battery powered RTU with an OPTEX EX-35R sensor is an optimal solution for long term, autonomous intrusion alarming. The EX-35R is an ultra low power PIR sensor, drawing only 3.5μA in standby operation. The PIR sensor is powered from the BSC-50D internal battery. A ‘Walk test’ option with LED indication can be selected, by a sensor internal jumper, for adjusting the detection range.

The sensor provides two Form C solid state switches (NO, NC, COM), one for motion alarm and one for tamper alarm. The sensor outputs are wired to the DI1 and DI2 BSC-50D digital inputs. The NO terminal is used for the Alarm input (DI1). For the Tamper input (DI2), the NC terminal is used, in order to include the case of cutting the cable. An ON-OFF switch, wired to BSC-50D DI3, is used to disable (On position) the GSM alarming (Disarm switch).

Up to 20 SMS recipients can be declared in the BSC-50D unit. The unit sends a Status SMS to the administrator on transitions between arm and disarm state. The unit can also send periodical status messages to the administrator, for verifying the system availability and GSM signal strength. A wireless RF Remote Control Switch, as the Velleman VM130 remote control set, can be applied in the place of a hand switch, for arming and disarming the alarm system remotely.

An additional digital input (DI4) is available for connecting door or window switches to the BSC-50D unit with a respective alarm annunciation.
The BSC-50D internal temperature sensor can be used to measure and record temperature with periodical data transfer. The unit can remain connected on the GSM network for a short period (up to 255 seconds) after sending a Status SMS, expecting a remote configuration SMS from the system administrator, e.g. add or remove a user, change timings and rates, etc.

Features

SMS Alarming
Autonomous operation for over 10 years
Arm/Disarm capability
Flexible user administration
Periodically sending status messages
Simple setup and installation
Remote configuration capability

Battery lifetime

Different low power sensors can be used for indoor and outdoor applications. The lifetime of the BSC-50D internal battery (LSH-20) depends on the current draw of the applied sensor. In some cases extra batteries for the sensors must be provided for the proper system operation. In the following table, the battery lifetime is calculated for different low power OPTEX motion sensors:

Sensor	Application	Sensor batteries	BSC-50E Battery lifetime [Years]	System operation [Years]
EX-35R	Indoor	–	>10	>10
CX-0702RS	Indoor	–	>10	>10
FTN-R/RAM	Outdoor	–	>10	>10
BX-80NR	Outdoor	–	>10	>10
VX-402R	Outdoor	–	>10	>10
AX-100/200TFR	Perimeter	2+2 ¹⁾	>10	>3 ²⁾
SL-350QFR/QNR	Perimeter	4+4 ¹⁾	>10	>8 ²⁾

¹⁾ SAFT LSH-20 batteries are recommended from the sensor manufacturer for transmitter & receiver.
²⁾ The transmitter’s batteries lifetime determines the maintenance free operation of the system.