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How to self-check the fault of household photovoltaic power station
- Aug 03, 2018 -

In theory, household photovoltaic power station can operate for 20-25 years, but even if the design and installation are very good, long-term operation will inevitably cause problems, so it is quite necessary to master certain faults.

If your PV system is not working, don't worry at this time. Remember that there are two main reasons why PV plants don't work: one may be equipment failure; one may be a problem with the power grid.

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1. Identify the problem.

By checking the system with daily power generation and monitoring software, it can be clearly seen that the system is not working or the performance is too low. This process should preferably be carried out during a sunny day to test the output of the PV modules and conduct a complete survey under sufficient sunshine hours.

2. Ircuit breaker, isolation device inspection

Ensure that the DC main breaker, isolators, and array AC main breaker are not disconnected. If all circuit breakers and isolation devices are closed, then a visual inspection of the inverter should be performed.

3. Inverter failure problem

Inverter fault is very common in the system. After all, it is composed of many components. The fault information of the inverter is often in the form of error information. Now the mainstream inverters on the market will have fault feedback function. The alarm light of the inverter will be on when the fault occurs.

According to the inverter alarm information, find the corresponding problem handling method in the inverter manual. If you still can't handle it according to the above method, you need to contact the manufacturer to solve it.

Of course, many times the inverter alarm is not its own problem, it may be a grid problem, or it may be a component problem.

4. Component failure investigation

The main causes of component failure are: cable disconnection or plug failure; loose connection within the PV manifold; breakage of the PV module.

Actual faults may be detected by physical examination of cables, components and current and voltage.

5. Photovoltaic array troubleshooting

For photovoltaic array fault detection, we should pay attention to the following basic understanding:

1) The open circuit voltage and short circuit current can be measured only when the PV module has no load.

2) Even when the solar irradiance is very low, the output voltage of the V module is close to the open-circuit voltage, and the short-circuit current is proportional to the effective solar irradiance.

3) The blocked PV module will not output current or reduce current according to occlusion condition.

Here we focus on the following two points:

1) If the DC side of the inverter fails, the first task is to measure the open circuit voltage of the PV array at the input of the inverter and confirm whether the DC power reaches the inverter. If there is no DC power at the inverter, the technician should systematically check the various devices and their connections. The detection process starts from the inverter and goes to the PV array.

2) For the self-inspection of the fault of the photovoltaic system, the user can develop good operation and maintenance habits after the photovoltaic power station is built, check the power station regularly, and accumulate some simple fault handling methods. When encountering related problems, Can solve the problem by yourself. If you can't solve it yourself, you can contact the manufacturer and ask a professional service person to provide guidance.