Control method, device and equipment of photovoltaic power source based on positive and negative sequence decoupling control

Abstract

The invention discloses a control method of a photovoltaic power source based on positive and negative sequence decoupling control. The method comprises the following steps: to begin with, obtaining atarget signal at an AC side of a power grid; then, carrying out decoupling on a positive sequence electrical signal and a negative sequence electrical signal in the target signal to obtain a reference signal; and finally, controlling a converter corresponding to the photovoltaic power supply by utilizing the reference signal. According to the scheme, the reference signal finally obtained throughdecoupling is obtained by carrying out comprehensive analysis on the positive sequence electrical signal and the negative sequence electrical signal at the AC side of the power grid, so that when thereference signal is used to control the converter of photovoltaic power supply, the active power output by the converter of the photovoltaic distributed power supply and DC bus voltage do not have second harmonic components (ripples), and influence on low voltage ride through capability of the converter in the photovoltaic distributed power supply is further avoided. The invention also discloses acontrol device and equipment of the photovoltaic power source based on positive and negative sequence decoupling control, and the control device and equipment have the effects 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...

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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

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