The solar inverter is the core component of the photovoltaic system, responsible for converting the direct current generated by the solar panels into alternating current. Its failure may directly affect the power generation efficiency of the entire system. The following are common types, causes, and brief troubleshooting directions for solar inverters:
1、 No output fault
The inverter cannot output AC power, and the system stops generating electricity.
Common reasons:
DC input abnormality: solar panel string fault (such as open circuit, short circuit), loose wiring or poor contact, resulting in DC voltage/current not being input to the inverter.
AC side fault: The connection between the inverter and the grid/load is disconnected, or the AC switch trips.
Inverter hardware damage: such as power module, main control board failure, or internal fuse blown.
Troubleshooting suggestion: Check if the DC/AC wiring is secure and if the switch status is normal; If there is no problem with the wiring, it may be an internal component failure that requires professional inspection.
2、 Grid connection failure
Inverters cannot be connected to the power grid normally, commonly seen in grid connected inverters.
Common reasons:
Abnormal power grid parameters: The voltage and frequency of the power grid exceed the allowable range of the inverter (such as high/low voltage, excessive frequency fluctuations).
Grid connection protection trigger: The inverter detects grid side leakage, islanding effect (the inverter still supplies power after the grid is cut off), etc., and automatically disconnects from the grid connection.
Communication failure: Communication interruption between the inverter and the power grid monitoring system, resulting in the inability to execute grid connection instructions.
Troubleshooting suggestion: Contact the power department to confirm the status of the power grid; Check if the inverter grounding is good and if the communication line is normal.
3、 Over temperature protection fault
The inverter triggers a protection mechanism due to high temperature, automatically shutting down or operating at reduced capacity.
Common reasons:
High ambient temperature: Poor ventilation at the installation location and prolonged direct sunlight exposure can cause difficulty in dissipating heat from the inverter.
Cooling system malfunction: Damaged cooling fan, excessive dust accumulation on cooling fins, or blocked internal air ducts.
Overload operation: The inverter operates at full load or overload for a long time, generating excessive heat.
Troubleshooting suggestion: Clean the dust on the heat dissipation components and check if the fan is running normally; Avoid prolonged high load operation of inverters in high-temperature environments.
4、 DC overvoltage/undervoltage fault
The inverter has detected that the DC input voltage exceeds the normal range.
Common reasons:
Overvoltage: When the weather is clear, the power generation efficiency of solar panels is too high, and the total voltage of the series connection exceeds the upper limit of the inverter's DC input (especially when multiple series connections are connected in parallel).
Undervoltage: Due to cloudy weather, insufficient lighting, or aging or obstructed solar panels, the input voltage is lower than the inverter starting voltage.
Troubleshooting suggestion: Check if the string connection is reasonable (to avoid overvoltage caused by too many series connections); Clean up any obstructions on the surface of the solar panel and evaluate if its performance has deteriorated.
5、 Communication malfunction
Inverter and monitoring system (such as backend monitoring, APP) cannot communicate normally, and cannot remotely view data or control equipment.
Common reasons:
Communication line issues: Network cables, wireless modules (such as 4G, WiFi) malfunction, loose wiring, poor contact.
Communication protocol mismatch: The communication protocol between the inverter and the monitoring system (such as Modbus, TCP/IP) is not set correctly.
The internal communication module of the inverter is damaged, such as network card or wireless chip failure.
Troubleshooting suggestion: Check the communication line connection and device IP settings; Restart the inverter or monitoring device, if communication still cannot be established, it may be a hardware malfunction.
6、 Abnormal indicator light/display screen
The inverter indicator light does not light up, flashes abnormally, or the display screen has no data/garbled text.
Common reasons:
Power failure: The inverter is not powered on or the internal power module is damaged.
Hardware damage to display screen/indicator light: such as screen aging and burnt out light beads.
Program malfunction: Inverter firmware program error causing abnormal display.
Troubleshooting suggestion: Check if the power supply is normal; If the power supply is normal, it may be a hardware or program problem, and the manufacturer needs to be contacted to update the firmware or repair it.
summarize
Solar inverter failures are often related to input and output parameters, environmental conditions, hardware aging, or wiring issues. In daily maintenance, it is necessary to regularly check the firmness of the wiring, the cooling system, and the status of the battery board to avoid the inverter operating in extreme environments. If a complex malfunction occurs, it is recommended to contact professional maintenance personnel or manufacturer after-sales service. Do not disassemble internal components by yourself.
