Static Synchronous Compensator For Electric Arc Furnace - China

Restrain voltage fluctuation and flicker

Eliminate harmonics

Improve power factor

Wanlida Static Synchronous Compensator

Main Functions

Improve the stability of power transmission

In long distance transmission system, Static synchronous

compensator (STATCOM) can not only compensate the power line

losses caused byreactive power, increase line voltage and

improve effective transmission capacity under normal

operation, but also offer reactive power adjustment in time,

damp system oscillation and improve system stability incase

of fault.

Maintain the receiving-end voltage level

Since high capacity load centers lack reactive power

support, it is easy to cause grid voltage dip, evencause

voltage collapse.

However, Static synchronous compensator

(STATCOM) is capable of fast var adjustment.

Therefore, the

receiving-endvoltage level is greatly stabilized.

Reactive power compensation leading to high power factor and

low line losses

Many types of loads need a mass of reactive power when

operation, such as asynchronous motors, arcfurnaces, rolling

mills and high rating rectifiers.

At the same time, the

upstream transformer and lineimpedance also generate

reactive power, which still leading to low power factor.

For the power system, loads with lower power factor will

increase the line losses, voltage drop anddeterioratevoltage

quality.

Additionally, reactive power will reduce efficiency

of power generation, transmission and distribution.

For

clients, low power factor will increase production costs.

Restrain voltage fluctuation and flicker.

Voltage fluctuation and flicker are mainly caused by rapid

loads variation.

This rapid variation also causesthe load

current fluctuation dramatically.

The current variation

leads to system voltage losses changingvery fast, which

brings the receiving-end grid voltage flicker.

The typical

loads that cause voltage flicker arearc furnaces, rolling

mills, electric locomotives, etc.

Static synchronous compensator (STATCOM/SVG) can offer fast

reactive power regulation, which mitigate voltage

fluctuation and flicker easily caused byloads variation.

Now, Static synchronous compensator (STATCOM/SVG) is the

best solution to restrain voltage fluctuation and flicker

compared with MCR, TCR etc.

Mitigate 3-phase unbalance.

In distribution network, there are a lot of 3-phase

unbalance loads, typically like electric locomotives and

arcfurnaces.

At the same time, line and transformer

impedance unbalances can also cause voltage

unbalanceproblem.

Static synchronous compensator (STATCOM)

can fast compensate negative sequence current caused by

unbalance loads, which ensurebalanced 3-phase grid current.

Thus, it improves the power supply quality greatly.

Eliminate harmonics including Even-order, Odd-order,

subharmonic and inter-harmonics(Option)

Static synchronous compensator (STATCOM/SVG) has very good

harmonic suppression functions including even-order

harmonic, odd-order harmonic, subharmonic and inter-

harmonics, it adopted Instantaneous power theory to detect

and calculate harmonic current automatically and then

control PWM converter, and input compensated current into

power grid which is of the right magnitude with harmonic

current, but with inverse polarity.

Structure of Wanlida Static Synchronous Compensator

It mainly consists of reactor, start-up cabinet, cascade

multilevel inverters cabinet and control cabinet.

Technical Advantages

Static Synchronous Compensator has the following advantages

compared with traditional compensation methods:

Faster response speed

STATCOM response time: ≤5ms

Traditional static compensator response time: ≥10ms.

STATCOM can finish the conversion from rated capacitance var

to rated inductance var in a very short time.

This

unexampled response speed makes STATCOM very suitable for

impact load compensation.

Stronger voltage flicker restrain capability

SVC can restrain voltage flicker to 2: 1 in maximum, but

STATCOM can achieve 5: 1, even higher.

SVC cannot improve its

capability for voltage flicker mitigation even with high

capacity because of low response speed.

But STATCOM responds

fast.

When its

capacity is increased, the capability of voltage flicker

mitigation can be further improved.

Wide operation range

STATCOM can work from rated inductive power to rated

capacitive power.

So compared with SVC, STATCOM operation

range is much wider.

Furthermore, STATCOM can output rated

reactive current even under low system voltage.

Multiple compensation function

STATCOM is not only functioned as fast reactive power

compensator, but also harmonics and unbalance compensator

according

to different demands of different clients.

Low harmonic content

STATCOM utilizes PWM, 3-level and multiple technologies.

Therefore, it generates very low harmonics with compensating

load

harmonics at the same time.

Thus, STATCOM becomes a true

multifunctional compensator.

Small volume

HV big capacitors and reactors are not necessary.

STATCOM

installation area is greatly smaller than that of the same

capacity SVC, only 50% or even lower.

At the same time, Wanlida cooperates with the No.

1 Science

university in China---Tsinghua University to develop SVG,

but the most important advantage for Wanlida is that we have

many years experiences for Medium voltage variable frequency

drives technology, because the Static Var Generator has

almost structure and technology with Medium voltage variable

frequency drives, in addition, Wanlida has over 21 years

experiences for protection relays for reactor, capacitor

etc.

Technical Features

Provides fast smooth dynamic compensation from inductive to

capacitive in reactive power, also eradicates reactive power

delivery to power grid, it can meet the maximum request to

compensate power factor and keep power factor close to 1.0

anytime.

Low power loss, more better economical operation.

Has powerful capability to support voltage and ability to

continuously operate under the 1.1 times of overload.

More fast response time and better effect for restraining

flicker.

Produce no harmonic and and compensate nearly all load

harmonics without amplifying them and without generating

harmonic resonance, it has more safety, stability and

reliability because it is not sensitive to the system power

parameters.

Modular design.

All power units are the same in structure

and electric performance, thus they are interchangeable,

which is easy for installation and maintenance.

Redundant

N+1 structure provides more higher reliability.

Less space for installation.

Technical Specifications

Rated voltage

6kV/10kV/22kV/27.5kV/35kV

Rated Frequency

50Hz (±2%)

Rated reactive output

Capable of continuous output that ranges from inductive

rated reactive to capacitive rated reactive

Connection mode

3phase3wires Star connection

Response Time

≤5ms

Active-power loss

≤2% of rated power

Overload capacity

Capable of continuous operation at 1.1 times overload

Harmonic characteristics

When it only compensates reactive power output, THDU <3%,

THDI <4%; harmonic suppression rate when harmonic wave

harnessing >85%

Allowable unequalization degree of voltage

The permissible value of unbalance degree of connection-

point system voltage shall not exceed 60%

Operation indication

Touch screen, full-digitalized control

Protection function

Power grid overvoltage, undervoltage, voltage imbalance;

overload, inverter over/undervoltage, overcurrent ,

overtemperature; capable of automatic exiting from the power

grid in case of a equipment failure

Communication modes

Ethernet; capable of background-computer remote monitoring;

reserved with RS485/232 interface

Cooling system

Forced air cooling

Factory Acceptance Test

We built the first-class high voltage and big capacity power

electronic equipments test platform to realize Factory

Acceptance Testing for whole machine before delivery.

Company Contact:

• Posted By: Zhuhai Wanlida Electric Co., Ltd.

• Phone: 867563395623

• Address: Wanlida Relay Protection Industrial Park, No. 1 Te, Zhuhai , China

• Email:

• Website: http://www.zhwld.com/

• Business Description: Incorporated in 1991, Zhuhai Wanlida Electric Co., Ltd. (www.
  
  zhwld.
  
  com)
  
  ('the Company'), is located in Relay Protection Industrial Park, No.
  
  1
  
  Technology Road, Science and Technology Innovation Coast, High tech
  
  Zone, Zhuhai City, coving a land area of approximately 60 thousand
  
  square meters (including Park 1 and Park2).
  
  The Company was listed for
  
  equity financing on November 13, 2007 (equity securities abbreviated as:
  
  Wanlida stock certificates, code: 002180), with a registered capital of
  
  124, 980, 000 Yuan.
  
  The Company keeps on her aggressive 'production,
  
  study, research and application' co operation with the famous academies
  
  such as Tsinghua University, Chinese Academy of Sciences and Central
  
  China University of Science and Technology and carries out relevant
  
  technology innovation.
  
  It is a national high tech enterprise that deals
  
  with specialized development, production and sales of substation
  
  integrated automation systems and Medium voltage variable frequency
  
  drives, Medium voltage magnetically controlled soft starters, Static
  
  synchronous compensator(STATCOM/SVG), Static VAR compensator(SVC),
  
  Active power filter(APF/AHF), Thyristor switched capacitor bank
  
  (TSC/TSF), High voltage direct current light transmission systems etc
  
  power electronic equipments.
  
  In addition, the Company is known as a
  
  famous manufacturer and backbone enterprise of transformer substation
  
  integrated automation and power electronic equipments fields in China,
  
  and it also acts as fresh blood in the field of energy conservation and
  
  emission reduction.
  
  Wanlida passed the ISO9001 quality system certification, ISO14001 Environment Management System Certification and OHSMS18001 Occupation Health &Safety Management System Certification; All products passed the test of sated authoritative inspection bureau.
  
  And it had been rated as 'National High and New Technology Enterprise', 'Enterprise Recommended by State Economic and Trade Commission for Reconstruction of Urban and Rural Electric Grids', 'Key Software Enterprise Covered by National Program', 'Excellent enterprise of China', 'First choice Manufacturer for Electric Framework Protocol Sponsored by CNPC', 'Excellent Enterprise of Guangdong Province', 'Optimum Good faith Enterprise of Guangdong Province', 'Contract honoring Enterprise of Guangdong Province', 'Top 10 Private Enterprises of Zhuhai City', and 'Enterprise with Grade AAA Bank Credit '.
  
  Wanlida has a very strong R&D teamwork which has a population of over 100 with doctor's degree, postgraduate degree and bachelor's degree etc, and all of the products are designed strictly according to IEC standards; Wanlida has modern standard workshops, it brought advanced SMT production lines and wave soldering machines into company from abroad, and built the first class high voltage and big capacity power electronic equipments assembling and test platform, which is able to realize full load test and ensure that all of products have exquisite technics and reliable quality; At present, Wanlida covers all of domestic areas except Hongkong, Macau and Taiwan, and it also sells the products to Southeast Asia, Middle East, South America, Africa etc over 20 countries.
  
  The Company aims to grow into the most dedicated electric automation enterprise in the world, and commits itself to building the aircraft carrier of power electronic energy efficiency products.