Composite-control active filter based on high-compensated precision current loop and control method thereof

Abstract

The invention relates to the active filter current loop composite control technology field and especially relates to a composite-control active filter based on a high-compensated precision current loop and a control method thereof. The filter comprises an active-filter general control circuit connected to a sampling side power grid. The active-filter general control circuit comprises a harmonic wave separation module. An output terminal of the harmonic wave separation module is connected into a load side power grid successively through a current loop composite controller and a filtering module. An output terminal of the filtering module is connected to an input terminal of the current loop composite controller. By using the filter and the method of the invention, all the periodic errors contained in a stable closed loop can be effectively eliminated and stable state precision is increased.

Description

technical field [0001] The invention relates to the technical field of active filter current loop composite control, in particular to a composite control active filter and a control method based on a high compensation precision current loop. Background technique [0002] Since the birth of the thyristor, because of its derivative power electronic products constantly changing people's daily life, the superiority of the power electronic products based on the thyristor has attracted more and more attention and references. At the same time, a large number of power electronic devices based on nonlinear loads such as thyristors have been introduced into the power grid, resulting in serious harmonic pollution of the power grid. This is mainly due to the non-linear, impact and unbalanced power consumption characteristics of these loads. Therefore, the active filter technology used for harmonic suppression has gradually become one of the research hotspots in the fields of power elec...

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Problems solved by technology

"However, this invention patent needs to set the maximum error current response value, which does not belong to the closed-loop adaptive control, and cannot self-adjust with the dynamic change of the load current.

The entire control method adopts open-loop control. When the set value and the actual required value of the system load are too large, it is easy to produce over-compensation or under-compensation.

It is difficult to define the maximum error current response value in the entire control system. For places where the actual load changes frequently, it is difficult to determine a reasonable value for the maximum error current response value.

In addition, in this control algorithm system, the error between the harmonic target current and the output current always tends to change continuously, and the obtained error value is then calculated with the set maximum error current response value for integer multiples and remainder multiples, which is just a disguised If the difference of PI tracking is reduced, it cannot really achieve the purpose of tracking without static error.

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