What is the effect of overvoltage in the PV system near the transformer?

 Overvoltage in a photovoltaic (PV) system near a transformer can create several technical issues, impacting both system performance and safety. Here’s a breakdown of the primary effects:

1. Inverter Tripping and Power Loss: Overvoltage can lead to inverter shutdowns, as most PV inverters are programmed to disconnect from the grid if voltage levels exceed specified thresholds. This is a protective measure to avoid damage but can cause significant power loss as the system shuts down temporarily. If frequent, this tripping reduces the overall energy yield and efficiency of the PV system.

2. Component Stress and Degradation: Persistent overvoltage stresses the PV system components, including wiring, transformers, and circuit breakers, leading to accelerated wear. Over time, these components may experience insulation breakdown, increased heating, and even potential failure, resulting in increased maintenance and repair costs for the system operator.

3. Increased Reactive Power Demand: In response to high voltages, inverters may attempt to inject reactive power to stabilize voltage levels. This can lead to inefficiencies and additional strain on the inverter. In some cases, reactive power injection may also create grid stability issues, particularly if the overvoltage affects other nearby grid-connected equipment or transformers.

4. Transformer Overheating and Potential Failure: When a PV system experiences overvoltage near a transformer, it can cause the transformer to overheat, reducing its efficiency and, in extreme cases, leading to insulation failure or thermal damage. This can compromise the transformer's lifespan, increasing the likelihood of costly replacements or repairs, and could even result in service outages if the transformer fails.

Mitigating overvoltage typically involves careful system design, including optimal placement of inverters, transformers, and wiring, along with advanced voltage control methods. Some PV systems use voltage regulation or active power curtailment to prevent overvoltage, ensuring both grid compatibility and system longevity.