DIRECT-CURRENT BUS VOLTAGE RIPPLE COMPENSATION METHOD AND PHOTOVOLTAIC INVERTER

摘要

A direct-current bus voltage ripple compensation method and a photovoltaic inverter. The method comprises: providing a photovoltaic assembly, wherein the photovoltaic assembly is connected to a single-phase DC/AC inversion module via a DC/DC conversion module and a bus capacitor sequentially; further providing a DC/DC bidirectional conversion module connected to the DC/DC conversion module and a storage battery connected to the DC/DC bidirectional conversion module; sampling a direct-current bus low-frequency ripple voltage signal in real time; when the direct-current bus low-frequency ripple voltage signal is in a positive half cycle, controlling the DC/DC bidirectional conversion module to enable same to work in a buck charging mode to charge the storage battery; and when the direct-current bus low-frequency ripple voltage signal is in a negative half cycle, controlling the DC/DC bidirectional conversion module to enable same to work in a boost discharging mode to discharge the storage battery. The method solves the problem of a relatively large direct-current bus voltage ripple that commonly exists in single-phase off-network type photovoltaic inverters, thereby reducing a ripple current that flows through a capacitor, reducing the system loss, and prolonging the service life of the capacitor.