How does a photovoltaic prefabricated cabin utilize its own photovoltaic power for initial startup and self-sustaining of the control system?

Publish Time: 2025-12-17

As a modular solution integrating equipment integration, rapid deployment, and intelligent operation and maintenance, photovoltaic prefabricated cabins are widely used in distributed photovoltaic power plants, microgrids, and off-grid energy systems. Especially in remote areas or emergency scenarios without external grid power access, the prefabricated cabin relies on its own photovoltaic power generation to achieve "self-starting" and "self-sustaining" of the control system. This capability not only concerns the system's ability to operate independently but also directly impacts the project's feasibility and reliability.

1. Tiered Power Supply Architecture: Ensuring Priority Power Supply for Critical Systems

A photovoltaic prefabricated cabin typically includes inverters, combiner boxes, energy storage batteries, relay protection devices, environmental monitoring units, and communication modules. To achieve self-starting, its power system adopts a "tiered power supply" strategy. First, the control system and auxiliary power modules are classified as "primary loads," powered by dedicated low-power DC-DC or AC-DC power modules; while the main power equipment serves as a "secondary load," only being put into operation after the system stabilizes. 1. In the absence of external power, as long as the photovoltaic modules receive sunlight and generate the minimum startup voltage, the system's backup power supply can be prioritized for charging via reverse connection protection diodes and the MPPT charging controller. Once the voltage reaches the threshold, the MCU is awakened and the initialization program is initiated.

2. Low-Power Startup Logic and "Soft Start" Mechanism

To avoid repeated start-ups and shutdowns due to insufficient power under low-light conditions, the industrial control system incorporates low-power startup logic. For example, only core sensors and communication modules are activated, while non-essential equipment such as air conditioners and lighting are temporarily not activated. Simultaneously, a "soft start" mechanism is employed: the inverter is first operated in low-power mode to gradually establish the DC bus voltage, while simultaneously detecting the grid status or energy storage status. Once the conditions are confirmed to be met, the main equipment is gradually loaded. Some high-end prefabricated modules are also equipped with a "black start" function—even if the energy storage is completely depleted, the system voltage can be automatically rebuilt after sunrise using only the photovoltaic array, without manual intervention.

3. Energy Management and Self-Sustaining Operation Strategy

Once the system successfully starts, the energy management system takes over global scheduling. It monitors photovoltaic power generation, load demand, and energy storage SOC in real time, dynamically allocating power flow. For example, during periods of ample sunlight, it prioritizes powering the control system, with excess energy charging the energy storage; at night, the energy storage supports the control loop, ensuring uninterrupted 24-hour online monitoring, remote communication, and fault alarm functions. Furthermore, the control system itself employs a low-power design: the MCU operates in a sleep-wake cycle mode, the communication module supports narrowband technologies such as NB-IoT or LoRa to reduce power consumption, and the display screen is only illuminated during operation. These measures collectively ensure the long-term self-sustaining capability of the control system under limited photovoltaic resources.

4. Redundancy and Safety Mechanisms Ensure Reliability

To cope with extreme conditions such as continuous cloudy and rainy weather, some photovoltaic prefabricated cabins are also equipped with miniature emergency power supplies as a "last line of defense," capable of maintaining critical data storage and remote alarms for at least 72 hours. Simultaneously, all power paths are equipped with overvoltage, overcurrent, and reverse connection protection to prevent damage to sensitive electronic equipment due to photovoltaic fluctuations.

In summary, the photovoltaic prefabricated cabin, through its hierarchical power supply architecture, intelligent startup logic, efficient energy management, and multiple redundancy protections, has successfully achieved autonomous startup and continuous operation without external power dependence. This not only enhances the system's adaptability in off-grid or emergency scenarios but also lays a solid foundation for building truly autonomous green energy nodes in the future.