Photovoltaic power supply control method, device and equipment based on positive and negative sequence decoupling control

Abstract

The invention discloses a photovoltaic power supply control method based on positive and negative sequence decoupling control. First, the target signal on the AC side of the power grid is obtained, and then the positive sequence electrical signal and the negative sequence electrical signal in the target signal are decoupled to obtain a reference Finally, the reference signal is used to control the converter corresponding to the photovoltaic power supply. Using this scheme, the reference signal finally obtained by decoupling is a comprehensive analysis of the positive sequence electrical signal and negative sequence electrical signal on the AC side of the power grid, so that when using the reference signal to control the converter of the photovoltaic power supply, it will not The active power output by the converter of the photovoltaic distributed power supply and the DC bus voltage contain the second harmonic component (ripple), which further avoids damage to the low voltage ride-through capability of the converter in the photovoltaic distributed power supply. In addition, the present invention also discloses a photovoltaic power source control device and equipment based on positive and negative sequence decoupling control, the effect is as above.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a control method, device and equipment for a photovoltaic power supply based on positive and negative sequence decoupling control. Background technique [0002] Due to the high efficiency of photovoltaic distributed power generation, it has been widely used in the power field. When an asymmetric fault occurs in the distribution network, the photovoltaic distributed affect the stability of the network. [0003] If an asymmetrical fault occurs in the distribution network, the current solution is generally to use the reference signal obtained by analyzing the positive-sequence electrical signal (positive-sequence voltage and positive-sequence current) on the AC side of the distribution network to control the current in the photovoltaic distributed power supply. However, when an asymmetrical fault occurs, since there will be negative sequence current or voltage in the distri...

AI Technical Summary

Problems solved by technology

[0003] If an asymmetrical fault occurs in the distribution network, the current solution is generally to use the reference signal obtained by analyzing the positive-sequence electrical signal (positive-sequence voltage and positive-sequence current) on the AC side of the distribution network to control the current in the photovoltaic distributed power supply. However, when an asymmetrical fault occurs, since there will be negative sequence current or voltage in the distribution network, the reference signal obtained by analyzing the positive sequence electrical signal (including only the signal related to the positive sequence electrical signal) is of great importance to the photovoltaic system. When the converter of the distributed power source is controlled, it is easy to cause the second harmonic component (ripple) in the output active power of the converter of the photovoltaic distributed The low-voltage ride-through capability of the device will be affected, and in severe cases, it will also cause the fault of the photovoltaic distributed power supply

Images