How to Choose the Voltage for Wind Turbine?

When a 5kw wind turbine is connected to a Deye inverter, should the voltage be set to 240V or 380V? Recently, a customer from the Philippines encountered this problem.

This customer is installing the wind solar hybrid system for his cold storage project. He has a Deye inverter and needs to purchase a wind turbine and its controller from us, and then connect them to his inverter. The solution we provided based on his actual installation conditions is a 240V wind turbine and the corresponding controller. However, other suppliers suggested that he use a 380V wind turbine. Therefore, the customer hesitated in the voltage selection.

Technically speaking, the voltage setting for a 5kW wind turbine generator should be 240V, which is more reasonable than 380V.

1. MPPT efficiency and dynamic matching: Locking the "optimal point"

The MPPT operating range of the Deye 5kW inverter is 150V – 425V (hardware limitation is 500V). When the wind turbine voltage is set to 240V, at the rated speed, the rectified DC output voltage of the inverter is approximately 240V – 320V. This voltage range is exactly within the "optimal operating point" of the inverter (that is, the most effective part of the curve), ensuring that it can track the maximum power under 80% of typical wind conditions.

However, if the wind turbine generator's voltage is 380V, at the rated wind speed or strong gusts, it is very likely to exceed 425V. In this case, the MPPT tracking function of the inverter will fail and limit the power output. If the voltage surges to the hardware limit of 500V, it will immediately trigger overvoltage protection (OVP) shutdown, or cause permanent damage to the internal IGBT components. Therefore, the 380V solution has almost no margin for error.

2. Effective Power Generation Time: 150V Startup Threshold

The Philippines has a typical island climate, and the power generation capacity of wind turbines largely depends on the "startup duration" at moderate to low wind speeds.

When the voltage of the wind turbine is 240V, it matches Deye's 150V startup voltage. It can start earlier at low wind speeds and then begin to supply power to the grid. Therefore, compared to the 380V system, its daily effective power generation time can be increased by 15% - 20%.

Then, although competitors claim that their line losses are lower, the 380V wind turbines take longer to reach the rated voltage at low wind speeds. More importantly, their voltage margin is narrower, which may cause the PWM controller to frequently trigger the "unload load" brake at high wind speeds, thereby interrupting power generation and causing unnecessary mechanical wear.

3. Structural Stability - The Primary Consideration for Cold Storage Projects

We are a professional provider of customized renewable energy solutions. Before designing a solution for our clients, we usually thoroughly understand the project background and actual needs of the clients. For this cold storage project, in order to ensure its long-term stable operation, our first consideration is the compatibility between the wind turbine's voltage and the client's inverter. Therefore, using a 240V wind turbine generator paired with a corresponding controller as an additional power supply is the most suitable solution.

This solution fully takes into account the long-term stability of the entire power system. It can provide sufficient "safety buffer" for the PWM decoupling load controller (allowing the brake to be set at 420V), ensuring that in strong wind conditions, the entire system can smoothly release excess energy through resistors instead of forcing the inverter to enter a safety "trip" state. With the addition of the 240V 5kW wind turbine, the entire photovoltaic and wind power complementary system can continuously and stably supply power to the cold storage.

However, the competitors set the wind turbine voltage at 380V, which only focuses on the theoretical line loss and ignores the compatibility with the inverter's MPPT parameters. It is unable to provide stable power supply for the customer's cold storage.

Finally, we would like to emphasize that the power generation equipment requires specialized knowledge and skills. We will balance the efficiency and safety of power generation and provide the most sincere advice to our customers.