Photovoltaic off-grid inverter control method and control device

Abstract

The invention discloses a photovoltaic off-grid inverter control method, and relates to the technical field of a photovoltaic off-grid inverter. The method is realized in such a way that by establishing a functional module architecture, a computer system is controlled by computer program instructions, and the computer program instructions are stored in a computer readable storage medium. A photovoltaic off-grid inverter comprises a mains supply rectifier module, a photovoltaic output control module, a battery and a busbar. An input end of the mains supply rectifier module is connected with a mains supply, and an output end is connected with the busbar. An input end of the photovoltaic output control module is connected with a solar panel, and an output end is connected with the busbar. The battery is charged from the busbar or discharged to the busbar. The control method is that if the solar energy is sufficient, the conduction angle of a switching element of a rectifier of the mains supply rectifier module is limited so as to be not less than a preset conduction angle limit value <theta>min. Thus, the case in which the rectifier is turned off due to that the conduction angle of the switching element is too small can be prevented, so that the mains supply rectifier module is ensured not to be turned off when the solar energy is sufficient.

Description

technical field [0001] The invention relates to the technical field of photovoltaic off-grid inverters, and specifically relates to a control method for photovoltaic off-grid inverters. The method is completed by establishing a functional module framework and controlling a computer system by computer program instructions. These computer program instructions are stored on a computer-readable storage medium. Background technique [0002] figure 1 Shown is a traditional photovoltaic off-grid inverter. When the solar energy is sufficient, the electric energy generated by the solar panel PV is transformed by the photovoltaic output control module (such as an MPPT module) and then input to the bus a. If the battery BAT is not fully charged, the power from the bus a a takes power for charging, and the inverter module takes power from bus a and inverts it, and then outputs it to the load to supply power to the load. If the solar energy is insufficient, the battery BAT supplies pow...

AI Technical Summary

Problems solved by technology

After the mains rectifier module is turned off, if the solar energy becomes unstable (that is, the solar energy is sometimes sufficient and sometimes not sufficient), and once the battery power is insufficient, it will cause the inverter output (that is, the output of the inverter module to supply power to the load) and Frequent switching between bypass outputs (i.e. supplying power to the load from the bypass output), which is not allowed

On the other hand, if the bypass bypass is abnormal at this time, since the mains rectifier module needs a period of time from startup to output energy, the load will be powered off during this period

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