Three-phase LCL type networking converter control system based on hybrid filter

Abstract

The invention belongs to the field of LCL type networking converters, and discloses an LCL type networking converter control system based on a hybrid filter. Comprising a first summator, a second summator, a controller and a hybrid filter, the grid-side current given quantity is connected with the first input end of the first adder, the grid-side current output quantity is connected with the second input end of the first adder, and the input end of the controller is connected with the output end of the first adder; the first input positive end of the second adder is connected with the output end of the controller, the second input negative end of the second adder is connected with the output end of the hybrid filter, the input end of the hybrid filter is connected with different state quantities of the LCL type filter, the output end of the second adder is connected with the input end of the amplifier, and the output end of the second adder is a modulation signal. The device has the advantages of being high in damping capacity, fast in dynamic response and easy to implement.

Description

technical field [0001] The invention belongs to the field of LCL type networked converters, and more specifically relates to a control system of LCL type networked converters based on a hybrid filter. Background technique [0002] In renewable energy generation (for example, photovoltaic power generation or wind power generation), in order to realize energy transmission, a grid-connected converter is usually required to convert DC flow into AC flow with constant amplitude and frequency. However, the output voltage of the network converter contains large harmonic components, which is difficult to meet the requirements of network access, so a filter link is required. Typical filter structures include L-type and LCL-type. The latter has greater harmonic attenuation capability (-60dB / dec) and the filter inductance can be designed to be smaller (favorable for high power density). Therefore, the LCL-type network conversion are widely recognized in the industry. [0003] Since th...

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Problems solved by technology

[0006] Aiming at the defects of the prior art, the object of the present invention is to provide a hybrid filter-based LCL type networked converter control system, which aims to solve the problem of dynamic and static performance caused by the weak self-damping of the LCL type filter networked converter in the prior art. bad question

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