Typical Scheme With 11kV distribution Network

11kV feeders Sub-station

33kV/66kV feeder

11kV feeder 1

11kV feeder 2

11kV

feed

er 3

11kV / 415VDist. Transformer

DistributionBox

• In India, the Electricity demand and availability has a wide gap. This makes it mandatory on Electricity Supply companies (EB) to go in for mandatory “Load Shedding”. The objective is achieved presently by shutting down few 11kV level feeders at Sub-station level.

• This is causing the entire area that is covered under the specific feeder to have “No Electrical Power”. This is causing a lot of inconvenience to residents staying in the area fed through the shut feeder.

• The technical Transmission & Distribution losses in EBs are to the tune of 15% to 21%. The kVA demand and usage can be brought down by Power Factor (PF) improvement. Present day scenario average PF is 0.8 , which if improved near 1.00, can cause these losses to reduce by @30% of its original value. i.e. reducing these losses by 6 to 7%. Presently, PF improvement is not carried out effectively.

• Distribution Transformers (DTs) used on 11kV feeders for distributing supply at LT level are not getting appropriately monitored for maintenance. This is causing an alarmingly high failures of DTs.

• “Electricity Theft” is another topic of concern for EBs. Presently there is no effective control on this. There is no or very little LT supply side Electrical parameter monitoring and their analysis.

Present day Scenario / Problems faced by EB:

Most Important is that Indian Government is committed to give 24Hrs Electrical Supply to all homes. That too by year 2012.

• Can carry out Load shedding at LT side on selective basis. This can ensure 24Hrs supply to homes and still achieve the objective of Electrical Load reduction so as to reduced demand.

• Can carry out dynamic Power Factor correction so as to maintain Power Factor near Unity (1.00). Causing substantial reduction in T&D losses.

• Can monitor DTs for faults and forces preventive maintenance so as to eliminate failures.

• Monitors all Electrical Load parameters for “Theft detection”, as well as complete information to EBs on loading patterns, fault events and exception reporting.

Where is PLMS fitted?11kV feeders Sub-station

33kV/66kV feeder

11kV feeder 1

11kV feeder 2

11kV

feed

er 3

11kV / 415VDist. Transformer

DistributionBox

RTU of PLMS

System

MCU of PLMSBased at DT circle.

Features of PLMS:

• Total Time based Load Shedding with 3-phase Loads (almost 85% of loads). But ensure 24hrs supply to homes through single phase (240Vac) loads.

• Automatic Power Factor Correction.

• Transformer Load parameters , Oil level and Over-Temperature monitoring for protection and informing preventive maintenance to DTs.

• Monitoring of Entire Load parameters Likeo Per phase values of Voltage, Current including Neutral values.o Frequency and Power Factor.o Power values Overall & Per-Phase for kW, kVA and kVAR.o Energy values kWh, kVAh, kVARh and MD values of kVA & kW.o Per phase Voltage & Current harmonics. THD and odd harmonics upto

15th harmonic.

• Connectivity on real time basis to “Master Control Unit -MCU” server PC by GSM (wireless) communication. All the Parameters, Faults & Events are available from “Remote Terminal Units” – RTUs. These RTUs can be remotely controlled or can be left to local control after setting schedules and settings of parameters.

MCU

What PLMS consists of ?

RTU1

RTU2

RTU3

RTUN

RTUs fixed on every D.T.

Windows basedProgram onPC .

PC at DT circlewith GSM modem.

WAN(Internet)

GSM-SMS communicationbetween RTUs and MCU

Web basedServer

MCU Control & Display

Hardware Requirement:•Windows based TAS-PLMS-Server Program.•Computer (PC) based at DT control location circle.•PC needed with Windows based operating system.•PC needed with MS-Access program (to be used as data processing program).•PC connected with minimum 8hrs battery backed UPS.•PC connected with GSM modem along with accessories.•PC connected with Broadband or Dial-up Internet connection.

Features of Software:•Control of RTU locations of 500Nos. Totally upto 500 DTs can be monitored / controlled.•Real time information availability of any RTU for various parameters monitored and controlled.•Recorded data viewing – along with Graphical display of various parameters.•MCU has facility to control the RTUs in “Remote Mode”.•Availability of Event records / Faults information on instantaneous basis and this information is sent to concerned maintenance personnel automatically through SMS.•Conversion of MS-Access database into SQL database for internet transfers.

MCU Control & Display

RTU Scheme of PLMS

LT feeder 2

LT feeder 1

Distribution Transformer11kV / 415V

MCCB 3-P

M1 M2

S1 S2

C1 C2 C3 C4

TAS PowerTekRLMS controller

Control Commands for

M1, M2S1, S2

C1, C2, C3, C4

Battery

GSMModem

RLMS – Controller by TAS PowerTekRemote Load Management Controller.

Features:•Programmable Operation and Remote Operation modes.•GSM modem drivers in built.•Intelligent Battery Charger in built.•Programmable Schedule control for 3-ph and 1-ph scheduling. Totally 8-Schedule events per feeder per day and total 4 types of pre-settings of day types.•4-step automatic Power Factor controller.•Monitoring of parameters Like V, I, PF, Frequency, kW, kVA, kVAR, kWH, kVARH, kVAH, MD-kVA, MD-kW, V-THD, I-THD, N-THD and odd harmonics upto 15th Harmonic.•Measurement Accuracy 0.5Class as per IEC-62053-22 for kW and 2.0Class as per IEC-62053-23 for kVAR.•Internal data logging for redundancy to GSM communication.•Monitoring transformer parameters like temperature and oil under level.•Totally 3nos of feeder control.