Regarding choice of sensor to measure current in grid tie inverter

Caliber,

This is pretty involved question, as there are several facets of the design that need to be considered. Are you designing a transformer-less, or a HF transformer DC/AC stage in your inverter? What type of inverter are you designing (central, string, micro?), and are you looking to implement a single MPPT, or multiple MPPT type module? What style of algorithm are you using to implement your MPPT (perturb and observe, incremental conductance, etc.)? These types of questions need to be taken into consideration to properly understand the needs of the measurement point and therefore the correct type of device to utilize.

At a high level, each of these types of sensing provides pros and cons given the way they operate in a system. For example, some pros and cons (this list is not exhaustive) of each could be:

Hall effect sensor
pros:

• galvanic or reinforced isolation 
• High working voltage (600V+)
• no loading effects, and very little burden voltage

cons

• Accuracy: Generally, these types of solutions are not as accurate as shunt based solutions
• Potentially Susceptible to external fields

Current Sense Amplifier

pros:

• generally more accurate overall
• cost optimization offerings

cons:

• Invasive measurement. Affects efficiency criteria, as well as thermal management
• burden voltage of the shunt can make them challenging/unusable on low voltage, high power lines (think FPGA core voltages of 800mV, several 10's of A)
• working voltage can be challenging (maximum Vcm product available from TI is INA293, which can handle up to 110V. Note that this is NOT +/- 110V, so these types of devices will not work for AC nodes)

Some collateral we have to help you get started would be to look at this power video series for current and voltage sensing for solar systems (the solar portion starts at 5:50 in the video). I would also invite you to check out this app note. While this is app note focuses on onboard EV charging systems, it does a great job of discussing the bullets above in more detail, and also goes into depth on some additional options, such as our isolated amplifiers, such as the AMC1300 family. Let me know if you have any additional questions.