Farady Electric Co., Ltd produces automatic reactive voltage regulators and capacitors for reactive power compensation. Reactive power compensation improves power factors, reduces losses and costs, increases capacity, and improves voltage regulation. Farady's voltage regulating capacitors smoothly adjust reactive output through tap changing, avoiding issues like overvoltage from switching. This provides efficient compensation with minimal maintenance needs and impact on grids. Farady offers indoor and outdoor capacitor and regulator units from 6-35kV for various reactive power and voltage control applications.
2. Reactive power compensation
Farady Electric Co.,:Ltd
+++++General
With the rapid development of national economy and the improvement of people's living
standard, people's demand for electricity is increasing day by day. It puts forward higher request to
the reliability and quality of power supply. However. Distribution network construction is seriously
lagging behind, the grid is weak, facilities aging, line length, small diameter, most of the power
distribution transformers are high energy consumption, network loss is increasingly prominent.
Voltage quality is one of the important indicators to measure the power quality of power
system, and its quality depends on whether the power flow distribution is reasonable or not. Due to
the increasing load and the power supply, the network structure of the power system not only
changes the network structure of the power system, but also changes the power distribution of the
system. May even cause serious problems in local areas, the situation is generally low voltage level.
This is not only related to the power system to provide users with power quality issues, but also
directly affect the safety and economic operation of the power grid. At the same time, it is
necessary to consider the power factor and voltage of the network, because the network power
factor and voltage reduction will make the electrical equipment is not fully utilized, thereby reducing
the transmission capacity of the network, and cause loss increase.
Reactive power compensation benefits
l Improves system power factor
l Reduces network losses
l Avoid penalty charges from utilities for
excessive consumption of reactive power
l Reduces cost and generates higher revenue
for the customer
l Increases system capacity and saves cost on
new installations
l Improves voltage regulation in the network
l .Increases power availability
3. Reactive power compensation
Farady Electric Co.,:Ltd
3. The need for capacitors in electric power system
+++++Product scope
Rated voltage๏ผ6kV to 35kV
๏ผ30kVโ230kV Power transformer substation๏ผ
Rated frequency๏ผ50Hz, 60Hz
Rated reactive power capacity๏ผ50kvarโ36000kvar
Environment temperature๏ผ-45โโ+55โ
Altitude๏ผ๏ผ4500m
Compensation taps๏ผ9 to 25 taps
Voltage regulation range๏ผ50%Unโ100%Un
Regulation reactive power range๏ผ25%Qnโ100%Qn
Impedance๏ผ๏ผ2.0%
Controller system๏ผDWK controller
4. Reactive power compensation
Farady Electric Co.,:Ltd
+++++ Working principle
The work principle of Farady regulating type capacitors is that: Connect all the capacitors to the electric
network with voltage regulator ,the output reactive power will be adjust by voltage regulator, refer to the
capacitor output power formula: QnUnUQc 2
)/(= .
The set of equipment is made up by following equipments:
1. Load break switch
2. Insolating switch
3. Voltage regulator
4. Intelligent controller
5. Capacitors
6. Lighting arrester
7. Metering CT, PT
Assuming that the nominal capacitance of the capacitor is Qn , the connected voltage regulator
regulation range is 50%Unโ100%Un, so refer to the formula QnUnUQc 2
)/(= ,voltage regulator is
designed with 9 taps tap changer to change the network voltage, see figure 2 , the output reactive
power in every regulator position
5. Reactive power compensation
Farady Electric Co.,:Ltd
Taps Voltage of capacitors( U) Output capacitors๏ผ Qc๏ผ
1 0.6 0.36
2 0.65 0.42
3 0.7 0.49
4 0.75 0.56
5 0.8 0.64
6 0.85 0.72
7 0.9 0.81
8 0.95 0.90
9 1 1
Figure 1 the output reactive power in every regulator position
+++++ Advantages
The traditional way of reactive power compensation is changing the quantity of capacitors to
adjust output reactive power, change method is usually switch or contactor, will result in following
hazards
1. The conventional reactive power compensation method has a large compensation capacity
and the adjustment is not flexible, it will lead to the compensation is not suitable , often appear over
and not enough.
2. The capacitor switching can cause over-voltage and inrush current, and it will seriously affect
and reduce the service life of the switch.
3. When the capacitor is switched on, as the capacitor will charged and discharged, when it need
to switch on again, which affects the speed of the switching.ใ
According to the above problems, o company developed the FLYK type reactive power
compensation device, has the following advantages๏ผ
6. Reactive power compensation
Farady Electric Co.,:Ltd
1.Energy conservation: Farady voltage regulating type capacitors will change the output
reactive power by regulating voltage on capacitors, so that the reactive power can be adjusted
smoothly. Comparing with other method, it can ensure the capacitors in best condition, the
energy saving effect is much better
2.Low cost๏ผIf the old power transformer substation need to reform, only need to add a voltage
regulator between the circuit breaker and capacitors, the original circuit breakers, reactors,
capacitors can be reuse, greatly reduce the cost of transformation
3.Maintance Free๏ผWhen traditional circuit breaker and contactor switching, switching devices
and capacitors often damaged because of the above problems, result in high maintenance costs,
using Farady devices, automatic control reactive power output, there is no potential risks of other
equipments, greatly reducing maintenance and staff costs in power transformer substation
Method Switch contactor Vol regulating type
No. of components Few Many Many
Compensation taps 1 4 9-25
Switch times 10000 times 100000times 100000times
Capacitor utilization Low Low High
Reduce inrush current With reactor With reactor No need of reactor
Over voltage High High Low
Impact on Power Grid Big Big small
Need Charge or not Yes Yes No
Action interval 30min 10min 1min
Switch failure rate High High Low
capacitor failure rate High High Low
Install type Outdoor& indoor indoor Outdoor& indoor
Cost Low Hight Low
Figure 2 Comparison of Three types compensation
7. Reactive power compensation
Farady Electric Co.,:Ltd
+++++ Intelligent controller
Figure 3 DWK controller
1. A controller can control the 1-2 power transformer, 1-2 capacitor group, through the menu
settings to meet different control situation. The control panel circuit can be used in different
equipment. Especially considering a series of adjustable capacitors and with a set of adjustable
capacitors, to achieve the maximum performance.
2. A voltage regulator is designed in accordance with the nonlinear voltage, so that the reactive
power capacity of each tap is equal. According to reactive power control and not according to the
power factor control, switching shocks does not appear.
3. According to the line switch and the main switch automatically determine substation operation
mode and automatically adjust reactive decision signal.
4. Dedicated capacitor protection, while protecting both the two regulator and capacitors, it will
set the protection value according to tap position of voltage regulator. Also with current delay,
instantaneous trip, opening voltage, overvoltage and under voltage protection system.
5. Each capacitor can be cast back at any time by pressing plate. Capacitor failure can
automatically exit the fault equipment, does not affect the operation of other equipment. Automatic
removal of the capacitor switch cabinet, and alarm.
6. With the communication interface and the contact type pressure regulating interface,
convenient and comprehensive automation.
8. A variety of models to meet the different needs of the controller.
8. Reactive power compensation
Farady Electric Co.,:Ltd
+++++ Equipment application
1๏ผCompact type
This type of devices install all electrical components in the cabinet that required, cabinet made of
galvanized steel or stainless steel, the voltage is 3 5kV and below, capacitance below 4000kvar will
use such structure. This type of structure is orderly, the installation and the maintenance are
convenient, the occupied area is small, and the structure is suitable for the interior installation of a
new power transformer substation.
9. Reactive power compensation
Farady Electric Co.,:Ltd
2 Outdoor type
This install type with a fence around the equipment enclosure , occupy an area of slightly larger,
but the maintenance is very convenient, also have in indoor and outdoor for use, this kind of
installing usually for old power transformer substation reforming and factory reactive power
compensation.
10. Reactive power compensation
Farady Electric Co.,:Ltd
3.Other applications
1๏ผWhen capacitor is the main compensation power, the reactive power problem is solved, the
line power factor is improved, the voltage drop is reduced, the reactive power loss is reduced, and
the terminal voltage level of the stable line is reduced. Suitable for urban and rural fringe areas,
since the overhead line is long, result in the voltage is too low,
2๏ผWhen the reactor is the main compensation reactive power, it mainly solves the problem of
large and seasonal voltage difference between day and night, and the problem of voltage instability.
Suitable for ultra high voltage hub substation, urban power grid, the day and night pressure
difference, the night capacitive reactive surplus places to install and use. The power frequency
voltage rise caused by the capacitance effect of long lines can be weakened when the overhead
line is empty or light load. Such end Voltage rise is due to the high voltage overhead line no-load or
light load, the line of the power grid for capacitive reactive power charging, resulting in line terminal
voltage is higher than the first voltage,
3๏ผWhen the capacitor and shunt reactor are combined as the main compensation of reactive
power, can Synthetically solve the problem of voltage reactive power. Suitable for large power,
power factor, voltage levels have higher requirements for the installation and use places.
4๏ผThe high voltage filter compensation device is used as the main compensation and harmonic
control of reactive power which mainly solves the problem of excessive harmonic and low power
factor. At the same time, it can also reduce the voltage drop, reduce the reactive power loss and
harmonic additional loss, and stabilize the terminal voltage level. For a harmonic source, medium
voltage overhead lines long, low voltage, low power factor of the installation site
11. Reactive power compensation
Farady Electric Co.,:Ltd
Copyright 2014 Farady Electric
Zhejiang Farady Electric Co.,Ltd
TEL:0086-577-61722510/61777258
Fax:0086-577-61777257
Http://www.farady.cn
Email:info@farady.cn
Add:Suโao,Liushi,Yueqing,Zhejiang,P.R.China, 325604