Large-scale photovoltaic DC series boost grid-connected system with power balancer

A large-scale photovoltaic direct current (DC) series boost grid-connected system with a power balancer, including N photovoltaic DC converters and N−1 power balancers, wherein N≥2. The output ends of the photovoltaic DC converters are connected successively in series and then connected to the DC grid, and the input ends of the photovoltaic DC converters are respectively connected to the output ends of the photovoltaic power generation unit. Among the photovoltaic DC converters, which are arranged successively in series, a power balancer is disposed between the input ends of two photovoltaic DC converters adjacent to each other. The N−1 power balancers are arranged corresponding to the set N−1 photovoltaic DC converters respectively to balance the input power of the corresponding photovoltaic DC converter, thereby eliminating a difference between the output voltages of the photovoltaic DC converters.