High-voltage parallel hybrid active power filter and iterative learning control method with forgetting factor

Abstract

The invention discloses a high-voltage parallel hybrid active power filter device and an iterative learning control method with a forgetting factor. The device is composed of a passive power filter, an active power filter and a coupling transformer. A steplength-variable fuzzy self-adapting harmonic wave detection method is adopted, so as to coordinate the requirements of steady-state performance and convergence rate of the system, and the detected electric network harmonic current is used as the system control target. An iterative learning control algorithm with the forgetting factor is adopted, and an improved Ziegler-Nichols method is utilized to realize the optimization of control parameters and improve the system control performance. The high-voltage parallel hybrid active power filter device has certain advantages in response time and control accuracy, can satisfy the requirements of large-capacity hybrid active filtering system, not only can well control the harmonic wave in the electric network, but also can compensate large-capacity reactive power, and is reliable in systems operation.

Description

technical field [0001] The invention relates to a power filter and a control method, in particular to a high-voltage parallel hybrid active power filter device and an iterative learning control method with a forgetting factor. Background technique [0002] With the development of modern industry, the power load is becoming more and more complex, forming the characteristics of large capacity and time-varying harmonics in the power system. At present, in the measures to control harmonics, the main solution is to install power filters, including passive power filters and active power filters. The passive power filter utilizes the characteristics of the inductance and capacitance elements to resonate with a certain harmonic to form a low-impedance branch in the impedance shunt circuit to reduce the harmonic current flowing to the grid. Although the passive power filter is low in cost, mature in technology, and can compensate reactive power, it can only filter specific sub-frequ...

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Problems solved by technology

The parallel resonant injection type APF does not have reactive power compensation capability; the capacity requirement of the series resonant injection type APF active filter is small, but it has a harmonic channel between the active power filter and the passive filter, causing active The compensation current injected by the power filter may flow into the passive filter and the system, which will unnecessarily increase the burden on the passive filter, and will also affect the effect of harmonic suppression

The form of connecting APF and PF in series and then connecting them to the power grid in parallel is called parallel hybrid active filter, which is suitable for high-voltage and high-power system applications, but generally in order to reduce the fundamental wave voltage borne by the active part and the flow through it Fundamental wave current, the fundamental wave impedance of PF is very large, resulting in large volume and high cost of PF device, so it is not suitable for occasions requiring reactive power compensation

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