Common Types of Steel Support Structures

1. Triangular Support Structure
This type of structure was widely used in early photovoltaic projects, as shown in Figure 1. It features front and rear legs of different lengths, which are bolted to the foundation. A diagonal brace supports the longer leg at its base and connects to the middle of the inclined beam. Longitudinal purlins rest on the inclined beam, forming the solar panel support system. This structure is a geometrically stable system with no redundant constraints.

The typical connection between the column base and foundation for such structures is illustrated in Figure 2. If the column base is considered as a hinge connection, the structure tends to deform significantly, requires more steel, and often leads to a high breakage rate of frameless photovoltaic modules due to deformation.

2. Modified Triangular Support Structure
The triangular support structure places high demands on the connection between the legs and the foundation. To address this issue effectively, the modified triangular support structure was developed. This design adds diagonal bracing to the original triangular structure, enhancing overall stability. Although it slightly increases steel usage, it reduces deformation by coordinating the movement of the front and rear columns. It is suitable for various types of photovoltaic module supports, especially in projects with high wind loads, uneven terrain, or mountainous areas where high structural integrity and minimal deformation are required.

3. Gable Support Structure
The gable support structure follows the "three-rigid-body rule" in structural mechanics: three rigid bodies connected pairwise by three non-collinear single hinges form a stable system with no redundant constraints. It is a simple binary structure. By eliminating the need for legs of different lengths, it reduces steel usage, simplifies the structure, and facilitates installation.

However, this structure has certain limitations:
1) Since it cannot adjust the height, it is only suitable for flat or gently sloping terrain.
2) The elimination of front and rear legs increases the overhang length of the beam. Under higher loads, the deformation of the structure increases, posing risks to the stability of the photovoltaic support system and the breakage rate of frameless photovoltaic modules. Therefore, the gable support structure is only suitable for environments with low wind loads.

4. Modified Gable Support Structure
To address the issue of high steel usage in the inclined beams of the gable support structure, a modified version was developed. This design incorporates features of the triangular support structure by adding a rear leg to the gable support, thereby reducing the overhang length of the beam. This enhances the stability of the support system and reduces the breakage rate of photovoltaic modules. The modified gable support structure uses only slightly more steel than the original gable design but is more economical compared to two triangular support structures.

5. Single-Column Photovoltaic Support Structure
The single-column photovoltaic support structure primarily consists of key components such as the main beam, secondary beam, front support, rear support, steel column, clamp, and single-pile foundation. It uses two diagonal braces to support the main and secondary beams, which in turn hold the photovoltaic panels. The connection between the steel diagonal braces and the single-pile foundation is achieved through clamps, making the structure simple and efficient.

Additionally, the single-column photovoltaic support structure occupies less space, allowing for efficient use of the land between front and rear rows of photovoltaic arrays. The front and rear supports of this structure are essentially elongated versions of the front and rear columns in dual-column support structures. However, due to the addition of clamps, steel columns, and other components, the single-column support structure requires significantly more steel compared to dual-column support structures.