I want to replace CT and PT sensor to LEM current and voltage sensor in hardware of DSTATCOM. Can anyone help me with a circuit design for the LEM current and voltage sensor circuits?
Dear Ravinder,
For sake of voltage and current sensing for acquisition you can use a resistive divider composed from large resistance and small resistance this potential divider is to connect it between the intended nodes for the voltage measurement. The tapped voltage can be input to a differential amplifier after that it can be applied to an A/D converter of data acquisition system. The total resistance of the potential divider must be high enough to avoid disturbing the measured circuit. The current can be sensed by a current sensing resistance Rm in the order of milliohms. The voltage drop on this resistance is amplified by a differential amplifier as has been done with the potential divider and accessed also by the data acquisition circuit.
This is a common practice for the current and voltage sensing for sake of acquisition.
Best wishes
You can refer to any application note to sense voltage and current using LEM .... for example,
Please have a look at page 122
http://eprints.nottingham.ac.uk/13260/1/Wesam_Rohouma_Thesis.pdf
Isloated operational amplifier works good. AMC1200 can be used to sense the voltage.
- Badges
- Science topic