what is UPFC?

2 Answers

Answer :

Unified Power Flow Controller (UPFC)

image


 

•UPFC stands for Unified Power Flow Controller.

•UPFC can control both active and reactive power flows in transmission system.

•UPFC uses solid state devices.

•UPFC is a combination of STATCOM (shunt) and SSSC (series) coupled common voltage DC link.

•It was invented for real time control and dynamic compensation of AC transmission system.

•UPFC can control simultaneously or selectively voltage impedance phase angle in transmission line and hence it is called UNIFIED.

•UPFC is a generalized synchronous voltage source (SVS).

•UPFC consists of two back to back voltage source converter operated by common dc link dc storage capacitor.

•The function of converter 1 is to supply or absorb real power demanded by converter 2.

•Converter 1 can be operated by unity power factor.

•Reactive power of converter 1 and converter 2 is independent of each other.

•Because no reactive power flow through dc link.

•The UPFC can operate only under balanced sine wave condition.

Answer :

UPFC stands for unified power flow controller. 

It's used for real time control & dynamic compensation of ac transmission system.

Related questions

Description : A Unified Power Flow Controller (FACTS controller) is a voltage source converter based (A) Inter-phase power controller (B) Static Compensator (C) Combination of series and shunt compensators (D) Solid-state series compensator

Last Answer : A Unified Power Flow Controller (FACTS controller) is a voltage source converter based Combination of series and shunt compensators

Description : Classify hydro-electric power plants according to water flow regulation and explain in brief.

Last Answer : Classification of hydro-electric power plants according to water flow regulation of water flow:-  1. Large reservoir power plant 2. Run-off river (ROR) power plant with poundage 3. Run-off River ... depends upon rate of flow of water Initial cost is less Its purpose is to generate electricity.

Description : The device which allows reverse power flow and withstands highest switch frequency is (A) GTO (B) MOSFET (C) IGBT (D) Inverter grade SCR

Last Answer : The device which allows reverse power flow and withstands highest switch frequency is MOSFET

Description : The power flow problem mathematical model for a linear transmission network (A) is non-linear (B) is linear (C) considers time variation of generation (D) does not consider tap-changing transformers

Last Answer : The power flow problem mathematical model for a linear transmission network is non-linear

Description : I'm Msc student in electrical engineering  and my project in control of the UPFC can you help me ?

Last Answer : UPFC means unified power flow controller. The control on UPFC is based on vector control approch proposed by Schauder & Mehta for Advanced static VAR compensators in 1991

Description : Temperature controller using SCR

Last Answer : Temperature controller using SCR The temperature control circuit is used to regulate the temperature. Figure shows the temperature control circuit using thermostat as temperature detector and SCR as ... half-cycle and heater gets connected to source to produce heat and raise the temperature.

Description : What is the purpose of auxiliary controller in substation?

Last Answer : The systems of substation auxiliaries ensure operation of substations providing internal consumers of substations with operating direct and alternating currents. Any breakdown (loss) of auxiliary systems ... whole substation, as well as serious problems during its subsequent putting into operation.

Description : Define Integral controller. State their advantages

Last Answer : Advantages of integral control action: 1) Improves steady state response 2) Removes offset error in the process variable. 3) Eliminates steady state error

Description : When to select P-I controller? Give any two application of P-I controller.

Last Answer : Selection of P-I controller:  The PI mode of controller is commonly selected for slow-to- moderate speed processes.  Fast response of the system is not required.  Large disturbances and ... an issue.  As a adaptive controller for flow process.  Real time pressure control process.

Description : Draw and explain pneumatic proportional controller.

Last Answer : Explanation : Basic : Proportional control is one in which the process input is change in direct proportion to the error(t) controls the output so that the manipulated variable and the error has proportional relation. ... the MV and SP reference value called as error Given as :  Error = SP - MV

Description : Explain three phase half wave controller or three phase unidirectional controller.

Last Answer : Three phase half wave controller or unidirectional controller:

Description : Explain Three Phase Bidirectional Delta Connected Controller.

Last Answer : Three Phase Bidirectional Delta Connected Controller:

Description : Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

Last Answer : The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller. The principle of ON-OFF control: The on-off control is also called an integral cycle ... control. In phase control, the switch is on for some period of each cycle.  

Description : Explain three phase full wave controller.

Last Answer : Three phase full wave controller: Three phase full wave controller is also called as the three-phase bidirectional controller. Let the load is star connected so at each phase there are antiparallel connected SCRs. ... conduct at the same time and the third phase will be open.

Description : Explain Keypad controller.

Last Answer : Keypad Controller: It's a device which interfaces between the computer and keyboard. That is a input device and used for transfer the data to connected device.

Description : How does a capacitor improve power factor?

Last Answer : Every circuit are usually more inductive than capacitive.it means that the current lags by voltage at small angle.hence we have to compensate this situation so we use Capacitor then this lag is compensate ... angle becomes low and the value of cos(phase angle) is increase and hence power also max.

Description : What is the formula for reactive power?

Last Answer : The formula for reactive power is, Reactive power = VI sin (phi) The unit of reactive power is VAR ( Volt ampere reactive). The reactive power is denoted by 'Q'. The formula for real power is, Real power = VI cos (phi) The unit of real power is watts. The real power is denoted by 'P'.

Description : reactive power is greater in load side compare to generator what will happen?

Last Answer : VI*sin()

Description : Explain The Flow Of A Typical Instruction Word.?

Last Answer : Answer :The flow of a typical Instruction word is as follows: The content of the program counter of 2 byte is transferred to the address register known as MAR ( memory address register ). This ... bus. Now the data is placed in the instruction register which will eventually decode and execute it.

Description : Axial flow compressor 

Last Answer : Axial flow compressor : Working Principle: As the fluid enters and leaves in the axial direction, the centrifugal component in the energy equation does not come into play. Here the compression is fully ... the absolute velocity of the fluid and the stator converts this into pressure rise. 

Description : Draw venture meter and write steps to measure flow rate.

Last Answer : Venturi meter consists of three sections that is converging section, throat section and diverging section. The flow is introduced to the meter through the inlet with diameter D' . The inclined angle ... to 15o . Flow rate is proportional to the square root of the differential pressure.

Description : List variable flow meter. 

Last Answer : 1. Variable area : Rotameter 2. Variable head : a) Venturi b) Orifice c) Pitot tube d) Nozzle

Description : Does current flow through a capacitor ?

Last Answer : Imagine a pipe with a flexible diaphram in the middle separating two haves of the pipe. Now the pipe is filled with air. If you apply a pressure to one end the diaphram will deform ... capacitor, the effects on electrons will be recreated across the boundary. But theres no electrical connection...

Description : State advantages & disadvantages of electromagnetic flow meter.

Last Answer : Advantage: Provides wide linear range. 2) Ability to measure reverses flow. 3) Gives rapid response to flow changes. 4) No obstruction is created to flow. 5) It can handle corrosive as ... and pipe networks with relatively short inside diameters. 3) It is useful for electrically conducting fluid.

Description : Compare variable head flow meter with variable area flow meter.

Last Answer : Parameter Variable head flowmeter Variable area flowmeter Working principle Restriction or obstacle is placed in the path of flow to create a differential Pressure. The pressure ... viscous fluid slurries and dirty fluids. In laboratories and testing and production lines.

Description : Describe principle of operation of Doppler type ultrasonic flow meter with diagram. 

Last Answer : Diagram: Working:  The flow meter consists of a crystal transducer mounted outside the pipe in which flow is to be measured. This transducer is a piezoelectric crystal which ... , so the frequency of the reflected wave is shifted to particle velocity, according to Doppler principle.

Description : Define laminar flow and turbulent flow.

Last Answer : Laminar flow : When a fluid flowing through the pipe at different speeds (fast at center and slow at edges), and the fluid particles move in layers with one layer sliding over the adjacent ... successive cross sections, then this flow is called as turbulent flow. Reynolds no is greater than 4000 

Description : In load flow Study, a PV bus is treated as a PQ bus when

Last Answer : Voltage at the bus becomes high 

Description : Load flow studies involve solving simultaneous  (1) linear algebraic equations. (3) linear differential equations. (2) non-linear algebraic equations. (4) non-linear differential equations.

Last Answer : Load flow studies involve solving simultaneous non-linear algebraic equations.

Description : The current flow in a battery is due to ______ A) movement of ions B) movement of protons C) movement of holes D) movement of neutrons

Last Answer : The current flow in a battery is due to movement of ions

Description : Precise control of reactive current flow entering the transmission and distribution systems can be minimized by using (A) synchronous condenser (B) static VAR capacitor (C) capacitor bank (D) thyristor switched reactor in parallel with capacitor

Last Answer : Precise control of reactive current flow entering the transmission and distribution systems can be minimized by using (A) synchronous condenser (B) static VAR capacitor (C) capacitor bank (D) thyristor switched reactor in parallel with capacitor

Description : lf the wire which is vertical to this page has electron flow downwards the conductor will have

Last Answer : lf the wire which is vertical to this page has electron flow downwards the conductor will have a counter-clockwise field in the plane of the paper

Description : Liquid flow rate is measured using (A) a pirani gauge (B) a pyrometer (C) an orifice plate (D) a bourdon tube

Last Answer : Liquid flow rate is measured using an orifice plate

Description : Inductance affects the direct current flow?

Last Answer : Inductance affects the direct current flow at the time of turning on and off.

Description : Do electrons flow from the anode to the cathode?

Last Answer : electrons flow from cathode to anode because the electron has a negative charge and repels from the negatively charged cathode whilst also attracting to the positively charged anode.

Description : What is the flow of electrons from one atom to another called?

Last Answer : Electric current

Description : What is the direction of flow of current?

Last Answer : Current  flows  from  anode  to  cathode(opposite  direction  to  flow of  electrons)

Description : What is the direction of the flow of electrons?

Last Answer : Electrons  flow    cathode   to   anode  or  in   an  oposite  direction  of   convection  current  flow  or  holes.

Description : What is the direction of the conventional current flow?

Last Answer : The conventional current flow in opposite direction of flow of electrons. The electrons flow from negative terminal of battery to positive terminal of battery. And conventional current flow from positive terminal of battery to negative terminal of battery.

Description : What is the direction of flow of electric current in an electric circuit?

Last Answer : It  flows  from  anode  to  cathode  (direction  of   holes  flow)

Description : Why do you need a closed circuit for electricity to flow?

Last Answer : When  the  circuit  is  closed  , a potential  diffrence  is  realized  between  the  two  nodes  connected  .This  causes  flow of  electrons  and  convection  current.

Description : Do you think the worst when the power is off?

Last Answer : Power is a big deal here, especially in winter. At various times power has been out for weeks and is very dangerous.

Description : Would a priority system for each households power help a power grid?

Last Answer : I’d make freezer and fridge number 1 and internet number 2. My bathroom has a window so it’s not as big of a deal.I also keep lots of LED flashlights handy just in case of power failure. Not perfect, but it works

Description : What is the priority for home power?

Last Answer : The unit is set to come on automatically when regular power is cut.

Description : Where is the nearest nuclear power station to where you live?

Last Answer : There are a few nearby. If a Fukushima like event happened I would have to leave permanently.

Description : When the truth becomes not "power", as the saying goes, but a burden, what do you do?

Last Answer : You denounce it as “fake news”.

Description : What determines the size battery needed (or used) in a device such as a flashlight?

Last Answer : How long might it be expected to last, like on a hunting trip, how compact is it /where will it be stored for potential use, how well will it fit the hand, what it’s expected use is/might be.

Description : How powerful was Apophis really?

Last Answer : Months to assemble a strike force of only two (2) ships, quickly overthrown, and no mention of him anywhere in my printed resources. Not very powerful, apparently…

Description : Is there an official Dragon Ball Power Level list on some websites?

Last Answer : I'd be surprised if there weren't a role-playing game that defines such. [Zaku Googles Dragon Ball Power Level RPG ... Oh, yep, there is. For example, here ] How official it is beyond that game, I don' ... 30,000,000 Android 18: 30,000,000 Android 19: 10,000,000 Android 20 (Dr. Gero): 10,000,000

Description : Do you have the freedom to say no? (details inside)

Last Answer : You can always say no. You’re not free from the consequences of saying no, however, such as getting fired.