Photovoltaic inverter parameter identification

Can LVRT test identify the parameters of a PV inverter?

In the case that the PV inverter control strategy and parameters are not disclosed, a method is proposed to realise the identification of the three types of parameters through the LVRT test. The method can solve the difficulty in performing the tests of Groups 2 and 3 parameters in the field.

What are the reference values for a PV inverter?

The reference values of the active and reactive currents can be expressed as follows: PDC−VDC curves with r = 0 Ω and r = 0.042 Ω, respectively. In the failure mode, the PV inverter operates at point G1 (actual operating point) when r = 0.042 Ω, and the DC voltage rises by 111 V.

How can LVRT test be used to identify a PV system?

To simplify the test items and steps needed for parameter identification, an appropriate identification and modelling method for a PV generation system is proposed on the basis of an LVRT test. This LVRT field test is conducted on a large PV system in North China. The three groups of parameters are identified with the test data.

How does a PV inverter work in failure mode?

In the failure mode, the PV inverter operates at point G1 (actual operating point) when r = 0.042 Ω, and the DC voltage rises by 111 V. The PV inverter operates at G2 when r = 0 Ω, and the DC voltage rises by 98 V. A noticeable difference of 11.7% exists between the two operating points.

What is the operating condition of a PV inverter?

The operating condition of 0.35 pu H is regarded as an example to verify the necessity of the equivalent resistance r. Fig. 5 shows the PDC − VDC curves with r = 0 Ω and r = 0.042 Ω, respectively. In the failure mode, the PV inverter operates at point G 1 (actual operating point) when r = 0.042 Ω, and the DC voltage rises by 111 V.

What are the environmental parameters of PV arrays?

Environmental parameters of the PV arrays The expectancy value of r is set as 0.03 Ω in the simulation model to make the set value applicable to various dip levels. After that, S and T can be solved under different test conditions based on the accurate modelling of point M first.