Wanlida Dynamic Reactive Power Compensator - China

Application industrial fields

Rolling Mill

The big reactive impulsion caused by rolling mills and other

industrial symmetric loads may lead to the following

problems to the power grid:

The voltage drop and fluctuation, which may result in

malfunction of electric equipment and reduce the productive

efficiency.

Low power factor

The harmful high-order harmonic waves in the driving

devices, typically 5th, 7th, 11th, 13th and side-

frequencies, which will cause serious voltage distortion.

Electric Arc Furnace (EAF) and Ladle Furnace

The electric arc furnace and ladle furnace are typical non-

linear and erratic loads in the power grid, causing a series

of adverse effects to the power grid:

Result in serious three-phase unbalance of the power grid,

and cause negative-sequence currents.

Produce high order harmonics, such as coexist of 2nd, 4th

even harmonics and 3rd, 5th, 7th odd harmonic, which make

severe voltage distortion become more complicated.

Serious voltage flickers

Electric Railway Traction Substation

While protecting the environment, the electric locomotive

also causes serious pollution to the power grid.

As the

electric locomotive is powered by single phase power system,

which not only causes serious three-phase unbalance and low

power factor but also generates negative-sequence currents.

Currently, the only way to solve the problem is to install

SVC system at appropriate locations along the railway.

The

SVC is able to balance the three-phase by means of single-

phase compensating and to increase the power factor through

filter capacitor.

Wanlida’s SVC is capable of solving this

problem perfectly at minimum cost.

Hoists and Other Heavy Industrial Loads

The hoists and other heavy industrial loads may cause the

following effects to the power grid when they are at working

state:

Cause the voltage drop and voltage fluctuation in the power

grid.

The harmful high-order harmonic currents

Wanlida’s SVC can solve above problems perfectly and help

customers obtain the following benefits:

Increase the power factor by dynamic reactive power

compensation

Eliminate the voltage distortion caused by harmonic

Stabilize the voltage and reduce the voltage fluctuation and

flicker

Balance the three-phase load current and eliminate the

negative sequence current

Increase the operation safety of impact loading equipment

and its adjacent electrical equipment

Long Distance Power Transmission

The power grid tends to have larger capacity and longer

distance, in the case of long-distance AC transmission, due

to the influence of Ferranti Effect, the voltage in the

middle of transmission lines will rise which will limit the

transferred power.

The capacitive power along the long

distance power transmission lines is in proportion to the

cable length and the square of voltage, so it will be

terribly surprising for capacitive current power to ground,

which results in the voltage rising of 1.5 to 2 times of

rated voltage at the end of transmission line and then

causes badly result.

The power utility usually install shunt

reactor to compensate capacitive current to ground to solve

voltage rising at the end of transmission lines, but if the

shunt reactor is of fixed capacity, it will be removed from

compensation system once inductive current is over desired

capacitive current to ground.

As usual, the operation of

shunt reactor connected in parallel to transmission line

wants a very high demand for switch, but until now, it is

still very difficulty to solve the over-voltage surge caused

by reclosing of switch, as a result, it results in bad over-

voltage accidents.

However, the SVC of MCR type of Wanlida

can solve those problems; it can regulate reactive power of

transmission line dynamically and fast.

The SVC of TCR can

not be directly installed in transmission lines with over

35KV, but the SVC of MCR can be installed in extra-high

voltage and ultra-high voltage transmission lines directly,

and it has no need of action of switching.

So the SVC of MCR

type is able to improve transmission and distribution

performance of the power system remarkably.

It should be

installed at one or several proper points in the power grid

in order to maintain a balanced voltage under different

conditions and achieve the following purposes:

Stabilize voltage of a weak system

Reduce the transmission losses

Enhance transmission capability and make existing power grid

more efficient

Improve transient stability

Increase the resistance in the small interference

Improve system damping

Enhance the voltage control and stability

Restrain the power oscillation and the sub-synchronous

resonance

Wind Power Plant

The output power of generator is always fluctuated

frequently because of variable wind power.

At present, the

popular asynchronous wind generator (including Doubly-Fed

Type) needs to absorb parts of inductive reactive power to

build magnetic fields, the paralleled capacitor banks can

realize compensation, but the stepped switching capacitor

banks can not meet fast and dynamic reactive power

compensation demand caused by variable wind power,

sometimes, if the capacitor banks can not meet reactive

power compensation in time, the wind generator will absorb

reactive power from the upper power grid, which will result

in low power factor of upper power grid and then cause

voltage fluctuation, so the state grid put forward the <

Regulations on State Grid Corporation Wind Farm Grid Access

Technology (Amendment)> based on voltage fluctuation,

flicker, frequency deviation, harmonics and lacking reactive

power.

The SVC of MCR can solve the above problems to meet the

demand of utility.

Secondary Substation (66KV to 110 kV)

In the regional power grid, the stepped switching capacitor

banks are used to compensate the system reactive power and

increase the power factor.

But they are only able to provide

the capacitive reactive power, and unable to realize rapid

and accurate adjustment according to the load variation, so

sometimes they provide much more reactive power than the

actual desired reactive power, which will result in over

voltage of the bus bar and damage the electric equipment and

destroy system stability.

Because the SVC of TCR can not be directly installed in

subtransmission lines with over 35KV, Wanlida’s SVC of MCR

will be most suitable for subtransmission, Wanlida’s SVC

system is able to compensate with capacitive and inductive

reactive power rapidly and accurately.

It solves the

problems of reactive feedback effectively.

In addition, when

a new SVC system is installed, the existing fixed capacitor

banks can be utilized by adding a MCR, which requires the

minimum investment.

It is the most effective way to improve

the power quality of the local power grid, the detail

benefits is as below:

Reduce the reactive power exchange with system and improve

system stability

Rapidly and continuously compensate the reactive power,

increase the power factor and improve the power quality.

Reduce the power losses of distribution system

Used in combination of stepped switching capacitor banks to

reduce the damage caused by frequent switching of capacitor

bank.

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.