PVDC 8301, 150 kHz - 30 MHz, 200A, DC-AMN (LISN) Photovoltaic Inverters

The conducted emissions of photovoltaic inverters at the mains terminals are usually measured using LISN according to CISPR 16-1-2. The circuit concepts of PV-inverters may cause ripple currents on the DC-side of the inverter. These ripple currents are passing through the cabling and the PV-generator modules and can be radiated as magnetic fields with sometimes remarkable disturbance effects. Traditional measurements at the PV-inverters' AC terminals will not be able to reveal such disturbance phenomena. The PVDC 8301 was specially designed to measure all kinds of disturbance voltages at the DC-side of photovoltaic inverters. These are in detail the disturbance voltage of one conductor above reference ground (unsymmetrical disturbance voltage), the common-mode disturbance voltage of a pair of conductors above ground (asymmetrical disturbance voltage), and finally, the differential mode voltage between two conductors.

Application:

The symmetric DC-LISN PVDC 8301 can be used for measuring of the disturbance voltage in the frequency range from 0.15 MHz to 30 MHz on photovoltaic inverters. It is designed with air-core or iron-free inductors to prevent intermodulation. The permitted continuous current is 200 A with activated fans. Without fans 100 A continuous current can be supplied. Short time currents over 250 A can be applied. The temperature of the built-in inductors may not exceed 150°C. The device under test is connected to the wing terminals of the front panel. The PV-generator or the PV-simulator is connected to the rear side.

The capacitor C3 was limited to 0.22 μF to avoid possible malfunction of the EuT. This leads to a differential mode decoupling of more than 20 dB. If higher decoupling values are required (e.g. 40 dB or more), the use of an additional 1 μF / 1500 V DC capacitor at the AE-terminals will bring significant improvements.