Answer / vijay

vvvfd means varieable voltage variable freqwency drive.

Answer / iamdon

The electric drive which uses variable voltage and variable
frequency for its operation and control is called VVVF
drives.With the technology improvement in the realm of
power electronics now it is more easy to work with VVVF.
Cycloconverters are employed to obtain variable frequency
up to 400Hz.

VVVF find applications in railways traction,airplane etc.

Author:arbelectbit@yahoo.com

Answer / shashi bhushan

generaly AC drive supplied with AC voltage , but where we
need variable source , there we use VVVFD(variable voltage
variable frequency drive).
raquirement for VVVFD.......
1.ac source
2.rectfier circuit.
3.filter circuit.
4.inverter circuit
5.IGBT

Answer / kaushal

varible voltage and varible frquency drive

my question is that....few days ago i had installed a three phase motor starter for an electric saw.the motor will run and make the hydraulic pressure which will be goes to pressure cylender by up and down lever.two number of limitswitches are also installed on cylinder for safety of motor.now when the arm of cylinder reaches to the upper or lower limit it will cut the motor's line.and motor will be stop.now wana know that what will i do that motor runs continue after the limitswitch cut it down but it shold not be made any pressure.pls answer me in brief.

3 Answers  

---

what is inrush curent.

5 Answers   BARC,

---

how generator avr give to the input?

0 Answers  

---

tate and explain super position theorem

2 Answers  

---

purpose of flux relay for turbo generator in power plant

1 Answers  

---

---

For these 2 devices what their power ratings are ? 1) single phase : AC 220V & starting amps 3Amps (i.e. starting torque) and the stabilized amps 2A ... For deep freezer 2) single phase : AC 220V & starting amps 2.7Amps (i.e. including the starting torque of a CRT monitor) and the stabilized amps 1 Amps thanks

1 Answers  

---

WHAT WILL HAPPEN IF INPUT SUPPLY OF RCBO IS CONNECTED TO OUTPUT SIDE

2 Answers   ABG Shipyard,

---

Require Generator Capcity ( KVA ) for 3 Phase Motor having 4.7Kw with starting current of 16amps?

1 Answers  

---

To measure insulation resistance of 11KV cable between core & armour, what should be the test voltage & duration?

4 Answers  

---

what is the rating of Insulation tester for measure 15 KW, 3 phase 415V 50 HZ induction motor?

2 Answers   ABB,

---

In Power transformer oil temperature or winding temperature will be high

3 Answers  

---

if we want to increase the back up time of an UPS what should we do ? if we want to decrease the charging time of a battery/batteries attached with the UPS what should we do ?

6 Answers  

---