Photovoltaic inverter array insulation impedance

What is the insulation resistance of a PV array?

The PV array insulation resistance was lower than 10 kΩ when every effect was included. New PV modules usually have insulation resistant about 150 MΩ or higher. The insulation resistance of the PV array, which consisted of 3,700 modules, was 40.54 kΩ, which was 4 times higher than the minimum input impedance between inverter input and ground.

How much insulation resistance should a PV inverter have?

A PV array insulation resistance lower than 10 kΩ can potentially affect the operation of the PV inverter. According to IEC 61646 Standard, a minimum of 40 MΩ.m 2 insulation resistance is required for a PV module with an area of greater than 0.1 m 2.

Can a PV array work with an inverter?

The insulation resistance of the PV array, which consisted of 3,700 modules, was 40.54 kΩ, which was 4 times higher than the minimum input impedance between inverter input and ground. This showed that PV arrays consisting of the new PV modules can work normally with the inverter.

What is a high voltage system in a PV inverter?

High voltage system in PV inverters operation requires a safe insulation resistance between the PV panel to ground. A poor insulation resistance less than 1 MΩ leads to a high leakage current (about 1 mA), which not only will damages the system but also injure the user.

How to calculate the insulation resistance of a PV module?

In the case that (R s + R p) is different in each module. From the insulation resistance data of the sampled PV module, the measured data is the value of (R s + R p) and the insulation resistance of PV array that are connected to the inverter can be estimated by using this formula.

How do you measure the insulation resistance of a PV inverter?

One method is to measure the insulation resistance of each panel with respect to ground. This indirectly also measures the leakage current. The measurement is usually done before the turning on of the PV inverter or at least once or twice per day. For a 1000 Vdc system, normal practice requires insulation resistance to be more than 1 MΩ.