Can Off Grid 3 Phase Solar Inverter be Connected to Mains Power Supply?

Off grid 3 phase solar inverter is a power conversion device whose main function is to convert direct current (DC) power into alternating current (AC). It transforms DC power from sources such as battery and solar panel into 3 phase AC power with the required frequency, voltage, and phase to meet the power demands of various 3 phase AC loads. For example, it can convert 48V DC battery into 380V AC power. Off grid 3 phase solar inverter play a crucial role in many applications requiring 3 phase AC power, such as industrial motor drives and solar power generation.

Can off grid 3 phase solar inverter be connected to the mains power supply?

Taking the Xindun HDSX off grid 3 phase solar inverter as example, it can be connected to the mains power as supplementary power source. However, it is important to clarify that the mains power connection is only for supplementing the backup power supply and is not used for mains power feeding. The mains connection follows the "only input, no output" principle; the 3 phase inverter only uses the mains power for load power supply and battery charging, and there is absolutely no backfeeding of power to the grid. When the mains power fails, the inverter will automatically switch to solar power supply, or be powered by combination of solar and battery power. Throughout the entire process, the 3 phase solar inverter always maintains non parallel, non on grid, and non feeding operating state.

If off grid 3 phase inverter is not connected to the mains power, it becomes a pure off grid solar energy storage system. During the day, when there is sufficient sunlight, it relies solely on solar power for both electricity supply and charging. When sunlight is insufficient, the battery will automatically discharge to supplement power, with both solar and battery powering the load. At night, without solar power, the system only provides power through battery inverter operation.

The HDSX off grid 3 phase inverter has two operating modes: mains priority mode and battery priority mode.

Mains Power Priority Mode – In scenarios where the mains power supply is stable, the grid priority mode prioritizes uninterrupted grid power supply, supplemented by solar/battery power.

When the mains power is normal, the mains power, after being regulated, directly supplies power to the load via the 3 phase solar inverter, without consuming battery or solar. Simultaneously, the mains power charges the battery. If the 3 phase solar inverter has built in MPPT solar controller, both mains power and solar power charge the battery simultaneously. The load's power consumption comes entirely from the mains power, with solar power used only for charging. This mode is suitable for scenarios requiring stable power, such as factories, computer rooms, shops, and office buildings.

When the mains power is abnormal (power outage/overvoltage/undervoltage/frequency exceeding limits), it will automatically switch to battery power supply. When the solar power generation is greater than the load power consumption, the solar power is directly supplied to the load, and the excess power is used to charge the battery. If the solar power generation is less than the load power consumption, the shortfall is supplemented by the battery, with the solar and battery working together to meet the load's power demand. When the mains power returns to normal, it will automatically switch back to mains power supply and charging mode.

Battery Priority Mode – When the battery is fully charged, the 3 phase solar inverter will force switch to battery powered operation even if the mains power is normal. When solar power is available, it prioritizes supplying power to the load, with any excess power used to charge the battery. If there is no solar power, the battery will provide power. If the battery voltage is low, the 3 phase solar inverter will automatically switch back to mains power, which will supply power to the load and charge the battery. If the solar phase inverter has built in MPPT solar controller, both solar power and mains power will charge the battery simultaneously. This mode is suitable for environments with no stable mains power, where solar power is for self consumption, and where electricity costs are high, such as remote islands or suburban areas without grid access.

Users can choose the appropriate operating mode based on their actual power consumption environment to maximize energy efficiency and optimize electricity costs. It is important to emphasize that although off grid 3 phase solar inverter support grid connection as supplement, they are still fundamentally off grid inverter, fundamentally different from on grid inverter. The core function of on grid inverter is to feed electricity generated from renewable energy sources such as solar into the public mains power, realizing surplus electricity fed into the grid and obtaining electricity price revenue. Off grid inverter, on the other hand, operate completely independently of the public mains power, even when connected to mains power, they can only draw power in one direction and do not have energy feedback capabilities.

Xindun solar inverter recommendation

The HDSX 3 phase solar inverter is off grid 3 phase solar inverter ideal for industrial and commercial applications. These users typically require inverters with high power and stable output. The HDSX off grid 3 phase solar inverter (3.2kW-160kW) is designed to meet the demands of high power, high load industrial applications, offering excellent conversion efficiency and stable output performance.

It not only supports 3 phase unbalanced loads but also features 3 input and 3 output, providing pure sine wave output at low frequency and 3 times the peak power. This easily meets the demands of complex and ever changing industrial scenarios, providing stable and reliable power for businesses and factories. The built in MPPT solar controller adapts to various battery types and configurations, satisfying diverse power needs, it can be charged by solar, mains power, or generator power.

The 3 phase solar inverter also features UPS power supply functionality. When connected to mains power, it stabilizes the mains voltage and supplies it to the load while simultaneously charging the battery. In the event of mains power outage, it immediately switches the battery's DC power to AC power via the inverter, providing continuous and reliable power support. This seamlessly ensures the continued operation of critical loads and helps enterprise users effectively prevent equipment damage.

Whether it's continuous operation of factory equipment, stable power supply for commercial sites, or independent power needs in remote areas, off grid 3 phase solar inverter can provide users with more reliable and flexible power solutions by reasonably introducing mains power supplementation on the basis of "independent operation," balancing stability and economy.