Monitor Line Voltage

The Telemetric Voltage Monitor (TVM) family of products offer a cost-effective voltage monitoring, interruption detection, and power quality solution. The TVM is available in single phase (TVM1) and two three phase versions, TVM3-120V and TVM3-277V. With these products, electric utilities can monitor and report power interruptions, over/under voltage alarms, and power reliability status throughout their distribution system, or at critical commercial/industrial customers. With Telemetric’s SCADA-Xchange™ and Reliability Monitoring System software, customers can integrate the TVM data into their SCADA, Energy Management, or Outage Management Systems, as well as produce accurate reliability reporting data for internal and regulatory use. Since the TVM products use the commercial wireless networks and cost-effective data plans, utilities can deploy solutions quickly and easily with no additional infrastructure investment.

Applications

• Distribution System Voltage Monitoring
  
  • Substation Regulators or Bus Potential Transformers
  • First Transformer downline of Hydraulic Reclosers – or utilize PTs
  • Lateral or Tap Monitoring
  • Mid-Point Voltage Monitoring
  • End of Line Voltage Monitoring
• Commercial & Industrial Customers or Critical Infrastructure
  

Benefits

• Simple Installation - just mount and connect to 120 or 277 VAC
  
• No Communications Set-up - Two-way communication automatically established over cellular control channel
• Easily Accessible Information - View either over the Telemetric Web Server, SCADA or OMS
• Remote Programming - Programmable operating parameters are remotely adjustable from the Telemetric Web Server

Operation

The TVM can give the exact location of the outage, sag or swell, reducing reliance on customer phone calls, which give only general area information. The TVM can be placed anywhere there is cellular phone coverage and 120 or 277 VAC power. The integrated cellular radio provides two-way communication with the fully automated Telemetric Network Operations Center (NOC). From the Telemetric NOC, information can be accessed though the Intelligent Web Server or can be sent to the utility's SCADA or Outage Management System using DNP3.

The line voltage monitor provides three primary functions:

• Power Interruption Reporting: Momentary and Sustained - supporting creation of IEEE Guide
  1366-2001 Power Reliability Indices: SAIDI, SAIFI, CAIDI, MAIFI
  
• Voltage Reporting Using the ITIC (CBEMA) Curve
  
• Over/Under Voltage Monitoring
  

Power Outage Reporting

Power outage reports are triggered when an outage occurs that is longer than a programmed time. The trigger time can be set to a value from 32 milliseconds to 10 minutes (default 32 mSec.) If the power continues to be off at the time of the outage call, a second call will be made when the power is restored. The Intelligent Web Server will also report the time duration of the first eight state changes and the final status of the power when the TVM called in.

Power Quality using ITIC (CBEMA) Curve

The TVM reports type II and III power quality events based on the ITIC (CBEMA) voltage acceptability curve, using three remotely programmable under-voltage set points and two over-voltage set points. A report is initiated when the AC voltage decreases below a preset level or increases above a preset level for more than a selected time period between 0.02 seconds and 60 minutes. The trigger levels for under voltages can be set between 80-125 Volts AC, while the trigger levels for over voltages can be set from 115-150 Volts AC.

Over/Under Voltage Monitoring

The present, minimum and maximum measured AC voltage can be reported at preset frequencies or anytime upon request. True RMS measurement of the steady state voltage provides highly accurate voltage readings. Readings can be measured as instantaneous values or can be averaged over a 96 second period (using a rolling average of 16 readings with a new reading every 6 seconds). The averaged value will filter out short voltage transients.

Reliability Monitoring System

The TVM family of voltage monitors are a key component of the Telemetric Reliability Monitoring System. The Reliability Monitoring System provides a utility with powerful tools for gathering data and reporting regulatory information required by public utility commissions or other regulatory bodies. The system automatically generates industry-standard power reliability performance indicators as defined in the IEEE Guide on Electric Power Reliability Indices 1366-2001, including:

• SAIDI (System Average interruption Duration Index)
  
• SAIFI (System Average Interruption Frequency Index)
  
• CAIDI (Customer Average Interruption Duration Index)
  
• MAIFI (Momentary Average Interruption Frequency Index)

Reliability Monitoring Datasheet

Hydraulic Recloser Monitoring

The TVM is a simple and inexpensive solution for monitoring single-phase hydraulic line reclosers. Install the Telemetric TVM at the next available 120 or 277 VAC secondary beyond the recloser and monitor the operations without modifying or reworking the recloser. The TVM reports recloser operations within 15 to 30 seconds, giving the time of the initial operation and the duration for each state change. The data is reported directly to the Telemetric Network Operations Center, allowing direct access by utility personnel, and remote notification via email or text pager.

SCADA/OMS Interface

While the Telemetric Intelligent Web Server offers a number of advantages, some utilities still need to get outage and voltage event into their existing SCADA systems. Rather than create custom interfaces for every system, Telemetric developed SCADA-Xchange. SCADA-Xchange allows the utility SCADA system to poll the Xchange Server using industry standard DNP 3.0 protocol. SCADA-Xchange translates the poll request, gathers the data and replies to the poll using DNP responses. No custom software is required, and setup and operation is easy. This option is described in more detail in the SCADA-Xchange datasheet.