Power Quality Management

Mar. 2015

Why measure Power Quality?

Increase of use of power electronics

● frequency inverters

● switching power supplies

● non-linear loads, modern lightning...

Increase of unbalanced and non-linear loads like large furnaces and rectifiers

Liberalization of energy markets

● More demanding power regulation due to increase of grid connected renewable energy sources

● Reduction of infrastructure investments

Reasons for increasing requirements for Power Quality

Bad Power Quality consequences

● Business normal operation can be interrupted causing significant economic damage

● Power blackouts in wider residential and business areas

● Interconnecting (exporting/importing) different distribution power grids may not be possible

Economical aspects:

● Malfunction of domestic appliances, medical equipment, laboratory apparatus...

● Burn-out of heavy industrial motors due to voltage unbalance

● Ageing and destruction of power factor correction capacitors due to harmonic currents

● Stopping and/or resetting of control systems that are dependent on a computer due to voltage interruptions

Technical aspects

How do we measure Power Quality?

● Power Quality can not be measured by standard measuring devices used for voltage/current/power monitoring

● Power Quality analysis is covered by two sets of standards which define:

Measurement methods for PQ parameters● They are defined with IEC 61000-4-30 standard and sub-standards for harmonics

and flicker

● Class A type of instrument is also defined by this standard

Class A PQ Analyser MC784/MC774

Class A measuring accuracy according to EN61000-4-30

Evaluation of power quality in compliance with EN 50160

Important features

● Power Quality analysis according to EN50160 with automatic report generation

● High accuracy (0.1%) as required within EN61000-4-30 Class A

● Measurement of 4 Voltages and 4 Currents with 32 kHz sampling time

● Waveform and transient recorder with programmable samplingtime (> 600 samples / period), pre-trigger and post-trigger time

● Automatic measuring range up to 1000 VRMS and 12.5 A direct connection

● Internal memory (up to 8GB) for recording all measuredparameters, waveforms, alarms, PQ reports and time-stampeddetails about anomalies.

● Serial, USB and Ethernet communication with support for MODBUS, DNP3 and IEC61850* protocol.

● Comprehensive energy measurement feature (4 quadrant energy measurement, 4 counters, up to 4 tariffs, tariff clock, pulse outputs...)

● Wide range of Input and Output modules

● Pqdiff and Comtrade data format support

* Availabe by the end of 2015

Advantages

MC784/774 combines ● functionality of PQ analyser● multifunctional measuring device● additional alarm functionality for control and supervision

operations

Wide range of input and output modules● monitoring other physical parameters inside transformer

station● controlling switches and other actuators…

Setting MC784/774 ● user friendly and intuitive setting software MiQen● software features and instantaneous help for all settings are

available in different languages

Real Time Synchronisation sources ● NTP, GPS, IRIG-B

Power Quality System

MiSMART – Introduction

WEB based application comprisedfrom

• Push Data Collector• Database• Client

Operating system independentsoftware

MiSMART vs SCADA• Not real time (except alarms)• Data lossless operation• Scalable and user-friendly• SMS and e-mail alarm notification

Standard SQL database• It can be used with other software

solutions

MiSMART – key functionalities

MiSMART Configuration Tools• Device data configuration• Setting up the system grid structure• User management

MiSMART Data Monitor• Measurement monitoring• Alarm monitor• Basic statistical functions• EN50160 power quality support• Table and chart data reviewing• Exporting data into Excel• Filtering relevant data from the grid• Data comparison from different meter

points• Virtual metering points• …

MiSMART – benefits

• Analysis of power quality in the grid for later corrective measures,• Cost savings due to faster response to outages for better maintenance,• Energy savings after corrective measures have been implemented,• Historical data for better planning,• Proactive equipment protection,• More reliable grid operation,• Better control of power theft and power losses in the network – this will

especially be obvious when more sites are equipped with PQ analysers.

Facts about the company

• Utility company operating MV andLV infrastructure

• 87000 customers• 1333 MV/LV transformer stations• 14 HV/LV transformer stations• WiMAX, GPRS & ethernet

communication• Project in operation for 2 years

Business case #1 – Elektro Gorenjska

Communication infrastructure:• WiMAX, GPRS, Ethernet• over 280 locations with (and growing)

Measurements:• Up to 60 measurements from each device• Sampling time from 1 to 10 minutes

Alarms:• voltage interruption• voltage high/low• frequency high/low• current high

Additional monitored signals:• Temperature – analogue signal• Intrusion detection – digital signal

Business case #1 – technical facts about the project

Voltage profile on several meter points

Business case #1 – application insight

• Remote and centralized measurement monitoring (Energy, active power, reactive power, currents, voltages, phase angles, maximal period values, minimal period values)

• Remote and centralized alarm monitoring in real time

• PQ parameter monitoring according to EN50160 on 19 locations• Real time information on the operation of installed equipment

• Excel and PQDIF data export capability for regulator reporting

• Better and faster maintenance planning according to historic data offered by the system

• Quicker response to failures as well as failure analysis

• Better supervision over energy losses within the power grid by comparing consumption data with the one of the billing system

• SCADA system integration over the IEC 60870-5-104 protocol

Business case #1 – key user benefits