Novel active filter fault diagnosis and fault-tolerant control improvement strategy

Abstract

The invention discloses a novel active filter fault diagnosis and fault-tolerant control improvement strategy which is characterized in that a hybrid system model method is used by a fault diagnosis method, a power supply current tracking method of voltage feed-forward control is used by a fault-tolerant control strategy, the influence of direct current midpoint potential shift caused by a split capacitor on a system is overcome, the control precision of the system is improved, the impact of fault tolerant switching on the system is avoided, and the reliability of the system is improved whilea good compensation effect is ensured. By using the novel active filter fault diagnosis and fault-tolerant control improvement strategy, a failure position can be rapidly judged, and the failure repair by the system is facilitated. Combined with a power supply current tracking compensation strategy proposed by fault-tolerant topology switching, the compensation effect is ensured, and the fault-tolerant switching is easy to realize. Direct current midpoint potential imbalance is suppressed by the voltage feed-forward control, and thus the system compensation effect is more stable in a fault-tolerant state.

Description

technical field [0001] The invention belongs to the field of fault diagnosis and fault-tolerant control, and in particular relates to a novel active filter fault diagnosis and fault-tolerant control improvement strategy of a hybrid system model method capable of quickly responding to fault types and fault locations. Background technique [0002] Shunt Active Power Filter (SAPF) is a new type of harmonic suppression and reactive power compensation power electronic device. The core component of SAPF is the inverter, but because the switching frequency is high, and the power device works at high temperature and high frequency for a long time, it is a vulnerable device. Once a fault occurs, the entire system of SAPF will not work normally, seriously may even lead to catastrophic consequences. [0003] In recent years, with the continuous development of inverters, many SAPF fault-tolerant control strategies with good effects have emerged, but there are also shortcomings: althoug...

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Problems solved by technology

The core component of SAPF is the inverter, but because the switching frequency is high, and the power device works at high temperature and high frequency for a long time, it is a vulnerable device. Once a fault occurs, the entire system of SAPF will not work normally, seriously may even lead to catastrophic consequences

[0003] In recent years, with the continuous development of inverters, many SAPF fault-tolerant control strategies with good effects have emerged, but there are also shortcomings: although most fault-tolerant strategies can achieve fault-tolerant control operation, they cannot distinguish between short-circuit and open-circuit faults , and the fault detection time is long, the actual effect is not obvious; the recent new fault diagnosis method is very practical, but its fault-tolerant control strategy does not take into account the influence of DC midpoint potential imbalance, which greatly reduces the compensation effect of SAPF

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