Grid voltage unbalance is a common issue that can impact the performance and longevity of hybrid solar inverters, including the SH15/20/25T models from Sungrow. Such unbalances occur when the voltage across different phases of a multi-phase system varies significantly. This can lead to inefficient inverter operation and might trigger protective disconnects. This blog post outlines steps to identify and resolve grid voltage unbalance issues with your Sungrow hybrid solar inverter.
Understanding Grid Voltage Unbalance
Grid voltage unbalance refers to disparity in voltage magnitude across the phases in a three-phase power supply. Such disparities can stress the inverter’s electrical components, potentially causing overheating and premature failure.
Signs of Grid Voltage Unbalance:
– Frequent inverter shutdowns or alarms.
– Reduced efficiency in power conversion.
– Abnormal sounds or behaviors from electrical appliances.
Step-by-Step Troubleshooting Guide
Step 1: Measure the Actual Grid Voltage
To begin troubleshooting, you need to determine if a voltage unbalance exists:
– **Use a Multimeter or a Voltmeter**: Measure the voltage on each phase separately at the point where your inverter connects to the grid.
– **Record the Voltage for Each Phase**: Note the readings and compare them. A difference greater than 3% between any of the phases can be considered significant.
Step 2: Contact the Electric Power Company
If you find a significant disparity in the phase voltages:
– **Report the Issue to Your Local Utility Provider**: Provide them with the voltage readings for each phase. They are responsible for ensuring that the voltage in their supply network is within regulatory standards.
– **Request an Inspection or Correction**: The utility company might need to adjust the distribution transformer tap settings or balance the system load to reduce the unbalance.
Step 3: Modify the Grid Voltage Imbalance Parameter
If the voltage difference between phases is within the permissible range set by the local power company but still causes problems for your inverter:
– **Access the Sungrow App**: Open the Sungrow monitoring app connected to your inverter.
– **Adjust the Grid Voltage Imbalance Parameter**: Navigate to the settings or system parameters section and modify the grid voltage imbalance settings to be more tolerant of the existing phase variation. This adjustment should only be made within safe and permissible limits advised by the power company and Sungrow.
Step 4: Contact Sungrow Support
Should the problem persist after taking these measures:
– **Reach Out for Professional Assistance**: Contact Sungrow’s customer support. Provide them with details about the issue, including your voltage measurements and any changes made to the inverter settings.
– **Technical Support**: Sungrow may offer further diagnostic support, suggest additional adjustments, or recommend a site visit by a service technician.
Conclusion
Handling grid voltage unbalance is crucial for maintaining the operational efficiency and health of your Sungrow SH15/20/25T hybrid solar inverter. By accurately measuring phase voltages, engaging with your local utility providers, and adjusting inverter settings through the Sungrow App, you can effectively manage and often resolve issues related to voltage unbalance. Remember, if these steps do not rectify the problem, Sungrow’s support team is essential for ensuring your inverter operates optimally. Always ensure that any adjustments or measurements are performed safely, or consider hiring a professional electrician to assist with troubleshooting
