30kW Pure Sine Wave Off Grid Solar Inverter

Off Grid Solar Inverter Catalog

What causes power grid voltage too high?

There are two situations, which will lead to the high voltage of the power grid. One is the place near the step-down transformer. In order to ensure the normal voltage at the place far away from the transformer, the output voltage of the transformer will be generally raised because of the line voltage loss. Second, the photovoltaic power generation user side cannot digest, because the transmission line has impedance and voltage loss, so the inverter output side voltage must be increased to send to the grid.

Voltage increase on the loss of power generation has three aspects, one is the solar power inverter overvoltage protection caused by inverter protection shutdown, at this time will be power loss. Second, the inverter overvoltage drop load, which is a new technology adopted by the inverter in the place where the grid voltage is too high. When the grid voltage rises to a certain extent, the inverter takes the initiative to reduce the power, to ensure that the inverter is not off the grid, so as to reduce the loss of downtime, but also a certain amount of power loss.

Three is the efficiency loss, power grid voltage increases, the dc bus voltage, as well as 400V ac voltage, dc bus voltage is controlled in 610V, general inverter rated voltage in this voltage range, set of string if around 600V voltage, PWM duty ratio close to 1, then inverter dc transform part of the most efficient, if the ac voltage up to 460V, DC bus voltage will ascend to 700V or so to satisfy, group string if it is about 600V, the voltage PWM duty ratio is 0.86, this time would reduce the efficiency of inverter dc transform part, about 90%.