Answer / md. zakir hosen

VFD means Variable Frequency Drives.A variable-frequency
drive (VFD) is a system for controlling the rotational speed
of an alternating current (AC) electric motor by controlling
the frequency of the electrical power supplied to the motor.

thanking u
http://a2zengineering.blogspot.com/

Answer / rohan k trivedo

simply we can understand vfd by the below relation

N= 120f/p
so in vfd speed will be controlled with the change in
frequancy. and frequancy can be changed by the thyristor
control pannel.

What is mathematical model of a control system?

0 Answers  

---

hi plz send me reliance placement papers..i.e electrical technical papers that have been asked in reliance test.

0 Answers  

---

Dear All, In a 400V power system, ratio of three current transformers installed incoming switchgear is 4000/1. Maximum three phases short circuit current of this system is 48kA. One CT is installed on neutral of upstream transformer (6/0.42kV, solidly earthed) for 51G protection. Would you please inform me about the correct CT ratio of this current transformer (on neutral)?? Thanks a million

2 Answers  

---

Fot testing new star-delta 132 kw motor in electrical worshop.we should check in star or delta connection as we do not have higher capacity cable in worshop?

4 Answers   Adani,

---

Why earthing transformer used in Distribution Sub-Station?

3 Answers  

---

WHAT CAUSED THRESHOLD VOLTAGE TO EXIST?

0 Answers  

---

critically criticize the application of ring main unit in power system

0 Answers  

---

Why armour HT XLPE power cable required to Earth?

1 Answers  

---

where this neutral connection goes after returning from the load(home ,factory,industries).Is it grounded at the transformer side or atthe generator side .If it is grounded then we also ground the earth connection.is there any problem with this.

1 Answers   IOCL,

---

Explain the advantages and disadvantages of thermal power plant?

0 Answers  

---

how will you calculate rated Primary and Secondary voltage and Current for 2500 KVA, 11kv/443V Transformer

2 Answers  

---

What is fuction of NGT/NGR using in Generator.

9 Answers  

---