In the application of photovoltaic inverter (PV inverter), current sensor are used in following two places;
1. DC Current Detecting and
2. AC Current Detecting.
In this page, we would like to propose you our recommendation of AKM products in each place with its superiority.
1. DC Current Detecting
On the DC side of PV inverter, current detection is required for 1.MPPT control to maximize power generation efficiency and 2. overcurrent detection caused by short circuit.
For improvement of system efficiency and realization of minituarization, it has been a challenge to achieve both high accuracy(low sensitivity drift) that correspond to MPPT control in current detection circuit and fast response required for over current detection at the same time.
If you use AKM's current sensor (coreless current sensor IC) , it is able to improve system efficiency and make it small size without compromising its safety function, because it realize high accuracy of 1.6% F.S. or less and fast response time of 1μsec or less (*1) in a high-voltage small SMD package.
(*1：For more detail about its data, please click here for Application Note.)
Besides, on the DC side, current flows in one direction. For the case that direction of the current flow is determined, unipolar type product is the most suitable.
By choosing the best unipolar type product, you can use highly sensitive products compared to bipolar type products and achive high resolution.
* Example (in the cace of detecting 10App); CZ3701 for biploar 200mV/A×10A=2000mV, CZ3720 for unipolar 400mV/A×10A=4000mV)
Advantage of AKM products
2. AC Current Detecting
On the AC side of the PV inverter, it is required to generate AC current that eliminates offset current (DC components) as much as possible in order to connect to a commercial power supply and sell electric power.
For AC side, closed-loop current sensors such as fluxgates have been commonly used because of its low offset characteristic, but its size and cost are the problems to be solved.
AKM' s coreless current sensor is the world's first open-loop current sensor in a surface-mounted package with low offset characteristic comparable to closed-loop current sensor.
In addition, because of its structure without a magnetic more, there is no magnetic hysterisis error in principle and you can have stable low offset characteristic.
By using AKM's coreless sensor, high accuracy (low offset drift characteristic) can be achieved while achiving smaller size and lower cost than closed-loop current sensors.
Advantage of AKM products
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You can select a product from the product specifications.
Click on the product series name to see the details.
|Coreless||SOP||5.0||5.0||100||± 115 to ± 225||Bipolar||Retiometric||≧ 8.0||1118||CZ375x||CZ375 Series||MP|
|60||± 5.3 to ± 180
|0 to 345.2||Unipolar||CZ372x|
|3.0||50||± 11.6 to ± 166.6||Bipolar||Non-Ratiometric||CZ3AGx||CZ3A Series||MP|
|3.3||3.3||± 12.9 to ± 129.1||CZ3A0x|
* Pollution Degree II with reinforced insulation