During my Ph.D. work, it was a requirement to sense the dc current on the PV side and ac current on the grid side. To sense the current I used a hall effect current sensor LTS25NP. This hall effect sensor is a bit costly however, it is excellent in working and easy to setup. Figure 1 shows this sensor. This sensor has three pins on each side and three in the front side. The three pins of left and right side should be shorted together. The output is from the front side. It should be noted that there are three pins on the front side and an arrow symbol. Arrow symbol shows the flow of current, this means that the positive terminal of the wire should be wired in harmony with the arrow direction.

Fig 1 : LTS 25 NP Click to zoom

For the proper reading of current, this ic required a stable 5 volt input connected between pin + and 0 of the front side. In order to have the stable and ripple free voltage, i have used a positive voltage regulator ic 7805. The output is available on pin out and 0 of the front side. Fig. 2 shows the circuit of LTS 25 NP current sensor

Fig 2: Click to zoom