Is there a risk if the inverter casing of a photovoltaic power station is too hot?

Introduction: As a power electronic device, the photovoltaic inverter mainly converts the direct current generated by the photovoltaic module into alternating current. Because there are thousands of electronic components inside it, and most of them are heat source devices, the heat dissipation design has a great impact on the life of the inverter. However, not all users know all this, so we often receive questions like: "I have an inverter device installed on the roof of my house, and the surface temperature of the chassis is hot. Is there something wrong with the inverter?" "Is the inverter going to explode?" and so on. The answer is of course not like this. Let's explain it to you through the analysis of mainstream heat dissipation solutions and third-party TUV data reports.

With the development of photovoltaic inverter technology and the improvement of efficiency, its heat dissipation form has changed from the initial full fan cooling to the following three mainstream heat dissipation designs.

1. Integrated die-casting mold fanless design

Advantages: First, the integrated heat dissipation of the upper and lower parts of the mold shell not only greatly increases the heat dissipation area, but also greatly reduces the heat transfer impedance; secondly, the internal heat source devices can dissipate heat very well, which not only ensures balanced heat dissipation inside and outside the inverter, but also keeps various devices in the best working condition.

Disadvantages: Customers have a misunderstanding about products with high power density and fanless design. They believe that insufficient heat dissipation of the device will lead to reduced power generation and shorten the life of the inverter.

Representative model 1: Inverter from manufacturer H. The internal temperature of the inverter is consistent with the temperature of the chassis shell. Under an ambient temperature of 45 degrees, the internal temperature is about 55 degrees;

Data source: TUV testing agency

Representative model 2: Inverter from manufacturer Y. The internal temperature of the inverter is consistent with the temperature of the chassis shell. Under an ambient temperature of 45 degrees, the internal temperature is about 60 degrees;

Data source: TUV testing agency

Solution 2: Ordinary sheet metal external fan design

Advantage: Lower chassis surface temperature.

Disadvantages: The inverter heat sink is small in size. Although part of the heat from the internal heat source device can be taken away by the fan, the heat dissipation of the entire heat source device is not uniform. In addition, the inverter also has the problem of high heat dissipation impedance between the outer box and the internal heat source device, and the internal heat is not easy to transfer to the surface of the chassis, so that the temperature of the internal device is much higher than the surface of the chassis, which may cause the equipment to work at a reduced rating or reduce the life of the internal device due to long-term heat exposure;

Representative model 1: S manufacturer inverter. The internal temperature of the inverter is about 15 degrees higher than the temperature of the chassis shell. Under the condition of an ambient temperature of 45 degrees, the internal temperature is about 65 degrees;

Data source: TUV testing agency

Representative model 2: S manufacturer inverter. The internal temperature of the inverter is about 15 degrees higher than the temperature of the chassis shell. Under the condition of ambient temperature of 45 degrees, the internal temperature is about 70 degrees;

Data source: TUV testing agency

Solution 3: Ordinary sheet metal fanless design

Advantages: The internal heat exchange design can quickly transfer the heat flow of the internal heat source device to the inverter surface;

Disadvantages: The shell is not designed for die-casting molds, and the heat dissipation impedance and heat dissipation area are inferior to those of die-casting mold products. Not only is the surface temperature of the inverter high, but a larger radiator (increasing the volume of the chassis) is required for support.

Representative model 1: Inverter from manufacturer G. The internal temperature of the inverter is about 15 degrees lower than the temperature of the chassis shell. Under the condition of an ambient temperature of 45 degrees, the internal temperature is about 55 degrees, but the surface temperature is as high as about 75 degrees;

Data source: TUV testing agency

Conclusion: Through the above analysis and data, it is not difficult to find that the outer box surface temperature of the fanless inverter (as shown in Scheme 1 and Scheme 3) is significantly higher than that of the fan-designed inverter, and this temperature can often reach 60 degrees. But don't worry that it will cause a fire because it is only the temperature of the outer box (60 degrees of the outer box belongs to the normal working range of the fanless inverter), and the internal temperature of the equipment is lower. The reason for adopting this design is to ensure the life of the device and the power station does not operate at a reduced rating to ensure power generation; looking at the inverter shown in Scheme 2, this is a typical case of a lower surface temperature corresponding to a higher internal temperature. It is conceivable that the device working in such an internal environment will reduce the life of the inverter. At this point, you may not be able to help wondering "What kind of design does Shengnengjie's product use?" The answer is clear: Shengnengjie's products use a fanless die-casting mold integrated design and a reasonable internal heat dissipation layout to ensure the best heat dissipation, longer life, and stable operation of the inverter.

About Shenzhen Shengnengjie Technology Co., Ltd.

Shenzhen Shengnengjie Technology Co., Ltd. focuses on the research and development, production, sales and service of photovoltaic inverter products. Relying on the strong supply chain and production strength of the parent company of the group, Asia Power Technology Co., Ltd., it brings together the top R&D talents, senior marketing, product and sales teams at home and abroad. Adhering to the corporate spirit of "professionalism, integrity, innovation and win-win", it takes Shenzhen as the starting point, faces China and goes to the world. Shengnengjie's Shenzhen production base is equipped with highly automated production equipment, and its manufacturing capacity and production capacity are at the forefront of the industry, and it has been awarded the title of National High-tech Enterprise.

As the holding parent company of Shengnengjie Technology, Asian Power Devices Co., Ltd. is a world-renowned power electronics product design and manufacturing company with sales of US$300 million in 2017. It ranks first in the world in the external power adapter market for network communications, printers, and storage devices. At the same time, it has been marketing its Prime VOLT brand photovoltaic inverters in Taiwan, Europe and the United States for more than ten years, and has the second largest market share in Taiwan.