Inverter selection parameters in a solar power plant

Inverter selection is a crucial aspect of solar power plant design, and a lot of considerations go into the decision-making process. A well-designed inverter can ensure maximum energy yield and overall system performance. In this article, we’ll explore the key parameters to consider when selecting an inverter for a solar power plant.

Type and Configuration of Inverter: One of the first considerations is the type of inverter needed for the solar power plant. In this case, a central inverter is specified. The configuration can either be outdoor in a container or indoor, depending on the EPC company’s choice. The inverter configuration plays a vital role in the plant’s maintenance and accessibility.

Efficiency: The inverter efficiency is a crucial factor to consider as it can significantly impact the overall system performance. In this case, the Euro Efficiency of the inverter is specified to be greater than 98.7%. Higher efficiency means more energy conversion from DC to AC power, leading to higher energy yield.

Total Harmonic Distortion (THD): THD is a measure of the distortion in the AC waveform generated by the inverter. A lower THD value means fewer harmonic distortions in the output waveform, resulting in smoother power output. A THD value of less than 3% is specified for this inverter.

Power Factor: Power factor refers to the ratio of the real power to the apparent power in an AC circuit. It is an important parameter to consider as a low power factor can result in system inefficiencies. In this case, the inverter’s power factor is specified to be 0.9, both leading and lagging.

Capacity: The inverter capacity is another essential factor to consider, and it should be selected based on the system’s requirements. The specified capacity for this solar power plant is 2.5MW or 3.12MW.

Maximum Input Voltage: The inverter’s maximum input voltage should be compatible with the system’s module configuration. In this case, the maximum input voltage specified is 1500V.

IP Rating: The inverter’s IP rating specifies its degree of protection against the ingress of dust and water. An IP 55 rating is specified for this inverter, which means it is protected against dust and low-pressure water jets from any direction.

Protection: The inverter should have protection against overcurrent, overvoltage, over-temperature, reverse current, surge protection, anti-islanding, and fault ride-through. These protection mechanisms are essential for the safe and efficient operation of the solar power plant.

Standards Compliance: Compliance with relevant international standards is crucial in selecting an inverter for a solar power plant. Some of the critical standards to consider in this case are IEC61727, IEC-61683, IEC 61000, IEEE 519, IEC 60068, IEC 62116, IEC 62109, EN 53030, and BDEW 2008.

Fuse Box: A fuse box is a crucial component in the inverter system and should be selected based on the plant’s requirements. The degree of protection specified for this fuse box is IP 2X for indoor and IP 54 for outdoor within the container. The fuse should be on the positive polarity, and the number of DC inputs should be as per the design requirement.

In conclusion, selecting the right inverter for a solar power plant is a crucial aspect of system design. Factors such as efficiency, power factor, capacity, protection, and standards compliance should be considered when choosing an inverter. Proper selection and installation of the inverter can ensure maximum energy yield, efficiency, and system performance.