Inverter——How to solve Error Code 9

Fault code【9】: PV overvoltage

Reason for malfunction:

Sudden change in illumination: In clear weather, when clouds suddenly block and then move away, the illumination intensity of the photovoltaic module will change significantly in an instant, causing a rapid increase in output voltage, which may lead to overvoltage.

Excessive number of modules in series: In the design of photovoltaic arrays, if there are too many photovoltaic modules in series, the total voltage of the series circuit will exceed the maximum input voltage limit of the inverter when there is sufficient light, resulting in overvoltage.

Improper cable selection: If the cross-sectional area of the cables used in the photovoltaic system is too small and the resistance is high, a significant voltage drop will occur when the current passes through. When the system load changes, it may cause excessive voltage fluctuations and overvoltage.

Inverter malfunction: The voltage control circuit inside the inverter has malfunctioned, making it impossible to regulate and limit the input voltage properly, which may cause the output voltage to rise abnormally.

Solution:

Install intelligent monitoring equipment: Install light and temperature sensors in the photovoltaic system to monitor environmental parameters in real time. When the light intensity or temperature changes too quickly, adjust the working parameters of the inverter through the intelligent control system, such as reducing the maximum power point tracking voltage to prevent high voltage.

Reasonably plan the number of components in series: Based on the electrical parameters of the photovoltaic modules and the input voltage range of the inverter, accurately calculate and adjust the number of components in series. Reduce the number of series connections appropriately in special environments such as high altitude and low temperature.

Choose appropriate cables: Based on the current size and transmission distance of the photovoltaic system, select cables with appropriate cross-sectional area to reduce line resistance and voltage drop. At the same time, regularly check the insulation performance and connection condition of the cables to ensure the safety and reliability of the circuit.

Repair or replace the inverter: Regularly maintain and inspect the inverter to promptly detect and repair faults such as voltage control circuits. If the inverter malfunctions severely, it should be replaced with a new one in a timely manner to ensure its normal operation.

Note: Please do not dismantle the machine without permission, otherwise it will be out of the warranty of Ktech.