In hybrid solar power system, hybrid inverters are often used in homes or small commercial applications, and their output is always single phase load power. So, can single phase hybrid inverter output three phase AC power? To determine whether single phase hybrid inverter can output three phase power, it's important to first understand the fundamental differences between single phase and three phase AC.
Single phase AC consists of only one live wire (L) and one neutral wire (N). The voltage waveform is a single sinusoidal wave with a fixed phase. Line voltage (the voltage between live wires) does not exist, and phase voltage (the voltage between live wires and neutral wires) is typically 220V/230V, which is used for household electricity, such as lighting and household appliances. Three phase AC power consists of three live wires (L1/L2/L3) and one neutral wire (N). The voltage waveforms of the three live wires are strictly 120° out of phase, and the line voltage (e.g., L1-L2) is √3 times (approximately 1.732 times) the phase voltage. This creates a stable rotating magnetic field and is used in industrial power scenarios for loads requiring high power and high stability, such as common industrial motors and commercial central air conditioners.
Conventional single phase hybrid inverter, due to their circuit design, only support single phase output and are unable to directly generate three sine waves with a 120° phase difference. Therefore, single phase hybrid inverter cannot directly invert and output three phase AC power. However, if single phase hybrid inverter is to be used to output three phase AC power, this can be achieved using single phase hybrid inverter with parallel functionality. At least three single phase hybrid inverter of the same model are connected in parallel, with each inverter generating its own AC output voltage. The three signals are maintained at a 120 degree electrical angle, forming a standard three phase symmetrical sinusoidal waveform. This results in three phase AC power.
This solution does not restructure the circuitry of the single phase hybrid inverter, but rather leverages parallel technology to expand its functionality. It retains the hybrid and complementary capabilities of the single phase hybrid inverter for PV, utility power, and batteries, while also meeting the power supply needs of three phase loads.
In practical applications, users can flexibly adjust the output power based on load demand when using inverter paralleling. For example, in industrial scenarios, when the power demand of the three phase load output on a particular phase is unbalanced, users can adjust the inverter's three phase parallel connection to achieve the desired load power output on that phase. Taking the Xindun HP PLUS+ single phase hybrid inverter (10kw/12kw) as an example, it features three phase paralleling capabilities, supporting up to six inverters in parallel to output three phase AC power. Three phase parallel connections of the inverters can form a variety of core combinations, covering both "load balancing" and "load imbalance" scenarios.
So, how do you connect single phase hybrid inverter in three phase parallel mode? For example, the Xindun HP PLUS+ hybrid inverter (10kw/12kw) offers seven different three phase parallel connection combinations:
①Three inverters in parallel form a three phase system, a "1+1+1" combination, with one inverter per phase, and each of the three inverters providing a phase (live wire).
② Four inverters are connected in parallel to form a three phase system. The first phase has two inverters, and the second and third phases have only one inverter. This is a "2+1+1" combination, where two inverters connect to provide one phase, and the remaining two inverters each provide one phase.
③ Five inverters are connected in parallel to form a three-phase system. There are two combinations: "2+2+1" and "3+1+1."
A "2+2+1" three phase system: One phase has one inverter connected to provide one phase, and the remaining two phases each have two inverters connected to provide one phase.
A "3+1+1" three-phase system: One phase has three inverters connected to provide one phase, and the remaining two inverters each provide one phase.
④ Six inverters are connected in parallel to form three phase system. There are three combinations: "2+2+2," "3+2+1," and "4+1+1." A "2+2+2" three phase system combination: Two inverters are connected in a group per phase, meaning each group of two inverters provides one phase.
A "3+2+1" three phase system combination: Three inverters are connected in a group for the first phase, two inverters are connected in a group for the second phase, and one inverter is connected in the third phase.
A "4+1+1" three phase system combination: Four inverters are connected in a group for one phase, and the remaining two inverters each provide one phase.
A parallel combination of three "1+1+1" inverters and six "2+2+2" inverters is a power balanced combination. A three phase "1+1+1" system has a total power of 30kw/36kw, making it suitable for small equipment with balanced three phase loads, such as small three phase motors and commercial three phase freezers. It is suitable for scenarios with basic power requirements and stable loads. The six "2+2+2" three-phase system has a total power output of 60kW/72kW. The three phase power is fully balanced, and the overall output power reaches the upper limit of this model's parallel operation, making it suitable for medium sized industrial loads (such as medium sized production lines and large commercial central air conditioners). It also provides enhanced redundancy. If one inverter on one phase fails, the remaining inverter on the same phase can still maintain basic power supply, reducing the risk of system downtime.
If users need to achieve "heavier loads on two phases and lighter loads on one phase" in a three phase load, or if the load power on one phase is significantly higher than the other two phases, unbalanced three phase combinations such as "2+1+1," "3+2+1," "3+1+1," or "4+1+1" can be used to suit the user's actual use case. The Xindun HP PLUS+ single phase hybrid inverter (10kw/12kw) not only features three phase parallel operation but also supports up to six inverters in parallel, achieving a maximum total power output of 60kw/72kw, providing users with great flexibility and scalability. This parallel function is particularly suitable for users who need to gradually expand their power systems. Users can select the appropriate number of inverters for parallel operation based on current power requirements, and can flexibly increase the number of inverters to expand the total system power as load increases.
The Xindun HP PLUS+ single phase hybrid inverter (10kw/12kw) can be configured in three modes: hybrid, off grid, and grid connected. It combines PV, utility, and battery power, and also supports battery-free operation. Equipped with dual MPPTs, this inverter can withstand a maximum PV input voltage of 500V. Its PV DC voltage MPPT tracking range is 125V to 425V. It uses a high frequency pure sine wave output and boasts an inverter conversion efficiency of up to 94%. In addition, it also supports time sharing charging and discharging settings, which can take advantage of peak and valley electricity prices and save electricity costs.
