What is a voltage mismatch in a PV system?

Author to whom correspondence should be addressed. In PV (Photovoltaic) systems, the PV array is a structure in which many PV strings are connected in parallel. The voltage mismatch between PV strings, in which PV modules are connected in a series, occurs due to a voltage decrease in some modules.

Do external mismatch effects affect conventional and hybrid PV arrays?

According to literature, the influence of external mismatch effects on conventional (i.e., SP, TCT, BL, HC) and hybrid PV arrays (i.e., SP-TCT, BL-TCT ) is addressed in multiple papers, which are reported in Table 1.

What happens if a parallel connected array is mismatched?

Although all modules may be identical and the array does not experience any shading, mismatch and hot spot effects may still occur. Parallel connections in combination with mismatch effects may also lead to problems if the by-pass diodes are not rated to handle the current of the entire parallel connected array.

Does HC interconnection reduce PV array mismatch loss?

The results proved that the PV array mismatch loss is directly proportional to the number of modules connected in series. The HC interconnection has less number of series connections; therefore, the mismatch loss is limited compared to SS and SP.

What causes voltage mismatch between PV strings?

The voltage mismatch between the PV strings was created by the operation of the bypass diode and the short-circuit failure of the bypass diode in the junction box. Experiments were conducted to analyze the electrical characteristics of each case of voltage mismatch.

What if voltage mismatch is less than 2 V?

Experiments were conducted to analyze the electrical characteristics of each case of voltage mismatch. If there is a non-uniformity of irradiance between PV strings or the operation of the bypass diode in PV modules, the voltage mismatch is less than 2 V.