Page 101 - E24 Electrical Notebook

Power Factor Correction & Active Harmonic Filters - 97

Comprehensive Solutions – Harmonic Active Filtering Medium Voltage Power Factor Correction Solutions

Modern electrical equipment imposes stringent demands on voltage ABB’s ABBACUS is a packaged reactive compensation system which
stability and power quality. The power network has to be free from combines both primary components and secondary control and protection
harmonics and other electrical disturbances. systems within a compact modular enclosure. The system can be
configured as either a fixed or switched capacitor bank. The switched
By installing harmonic filters several benefits are obtained: bank consists of single or multiple steps, automatically controlled to
improve power factor.
• Higher power factor, improved voltage stability & network losses ABBACUS has been developed to provide effective power factor
• Filtering of harmonics in the system correction for both electrical distribution utilities and large industrial power
• Reduced resonance problems / amplification of electrical disturbances users including mining, pulp and paper, chemical, petrochemical, wind
farms, plastics and heavy industrial applications.
A “clean” network also imposes much less strain on equipment and The ABBACUS is available in a range of MECB (Metal Enclosed
lengthens its life span. This means lower maintenance costs and lower Capacitor Bank) models and is suitable for voltage ranges between 1kV
costs for replacing worn-out equipment. and 24kV – for higher voltages please contact ABB.

What problems can harmonics cause? Design Configuration

• Increased losses, with machinery & cabling operating at increased The ABBACUS design consists of an incoming module and/or connecting
temperatures power modules housing the primary equipment with optional secondary
and ancillary equipment kits. This modular approach allows future
• Resonance between inductive & capacitive parts of the power network expandability.

• Malfunctioning of control systems since electronic meters, relays, etc Incomer Module
are matched to the fundamental frequency
The incomer module facilitates connection to the customer network. It
• Overloading of capacitors, leading to malfunctioning & premature ageing comprises of a high voltage compartment and a control cubicle allowing
• Interference with telecommunications & computers for a single point termination of power cables and control wiring.
• Disturbances in ripple control systems
• High currents in neutral conductors Power Module
Harmonics are not only found in industrial networks, they can also spread
into the distribution network and cause problems for other power users. The ABBACUS power modules, when energized, generate the reactive
power. They are designed to be interconnected to each other and the
The ABB Power Quality Filter (PQF) eliminates the harmonics present in incomer module. An appropriate power module can be selected
the supply system. It is insensitive to large network impedance changes depending on the required application.
due to change in network topology such as paralleling of sources, or
switching between mains supply and generator operation. Total Service Approach

Fundamental Only idistortion An ABB PQF active filter is ABB is committed to a total power quality service approach that goes well
Supply designed for installation in parallel beyond supplying just the equipment. Thanks to the unrivalled technical
to the polluting loads. It monitors backup of the global ABB organization, we support our customers through
icompensation Load the line current harmonics, as well every step of the project, from establishing the problem, identifying the
as the requirements programmed ideal solution and then installing and commissioning your power quality
Active by the user. It then generates for equipment. For complete peace of mind, we offer a comprehensive
Filter each harmonic frequency a equipment maintenance and repair service anywhere in the UK.
compensation current in perfect
Clean Feeder Load Active Feeder phase opposition that effectively
Current Current Current cancels it out. This is achieved by
monitoring the line current in real
Harmonic Order Harmonic Order Harmonic Order time and processing the measured
harmonics as digital signals in a
high-power multi-DSP (Digital
Signal Processor) based system.

The use of a closed loop control Closed Distortion
system in combination with the Loop Source
capability to select individual
harmonic components makes the Active
ABB PQF active filter the most Filter
precise active filter on the market.

Un-filtered Line Current (100 A / Div) 800 The use of active harmonic filters
enables installations to comply with
Filtered Line Current (100 A / Div) 0 even the most stringent of harmonic
regulations and guidelines such as
- 800 IEEE 519, G5/4, etc.

TIME (5 ms/div) Unlike other active filter products
on the market, the ABB PQF active
800 filters make it possible to set
individual harmonic target limits as
0 imposed by regulations.

-800 The PQF also offers Modbus RTU
communication facilities with the
TIME (5 ms/div) customer’s existing communication
network, enabling the PQF to be
easily monitored and controlled
from a remote location.

ABB Ltd Tel : +44 (0) 151 357 8400
Unit 6 Riverview Business Park Fax : +44 (0) 151 355 9137
Riverview Road
Bromborough Email : abbep@gb.abb.com
CH62 3RH Website : www.abb.com/uk