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Nonlinear control method of npc type three-level sapf in three-phase four-wire system

A three-phase four-wire, non-linear control technology, applied in the field of microgrid, can solve the problems of complex algorithm, large harmonics, and low control accuracy.

Active Publication Date: 2019-12-03
SHANGHAI UNIVERSITY OF ELECTRIC POWER
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Problems solved by technology

[0006] The present invention is aimed at the problems of the defects in the above-mentioned prior art, and proposes a nonlinear control method of a three-phase four-wire system NPC type three-level SAPF, which can realize three-phase four-wire system SAPF under balanced / unbalanced power grid control, reduce the harmonic current and maintain the balance and stability of the DC side voltage, which solves the problems of low control accuracy, large harmonics, and complex algorithms in the current common methods, and some methods can only be used in balance state, low power, Problems on single-phase SAPF

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  • Nonlinear control method of npc type three-level sapf in three-phase four-wire system
  • Nonlinear control method of npc type three-level sapf in three-phase four-wire system

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Embodiment Construction

[0072] A three-phase four-wire NPC type three-level SAPF nonlinear control method based on Lyapunov function. From the point of view that the dynamic equation of SAPF is non-linear, through the method of step S4, it is controlled by a non-linear passive controller, which can completely decouple the controlled quantity-compensation current; Compensate the wave and reactive power, and can compensate the harmonic component generated by the nonlinear load when the power grid is unbalanced; through the method of step S7, the introduction of the adjustment factor f can maintain the DC side capacitor voltage balance. Specific steps are as follows:

[0073] Step S1: According to figure 1 The circuit structure diagram of the three-phase four-wire system NPC type three-level SAPF is shown, and the three-phase four-wire system NPC type three-level parallel active filter SAPF is connected in parallel between the inverter and the power grid. Hughes law and state space averaging method, s...

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Abstract

The invention relates to a nonlinear control method for a three-phase four-wire system NPC (Neutral-Point Clamped)-type three-level SAPF (Shunt Active Power Filter). Through a nonlinear control internal loop based on a Lyapunov function, the compensated current of a controlled quantity is decoupled completely, and dynamic and static characteristics of the system can be improved; through external loop voltage control of a proportional integral PI, the DC-side general voltage can be effectively made to be maintained at a set value; and through introducing an adjustment factor f, the DC-side voltage keeps to be balanced. Compared with the prior art, the method has the advantages of an advanced theory, good dynamic and static characteristics and the like.

Description

technical field [0001] The invention relates to a micro-grid technology, in particular to a three-phase four-wire NPC type three-level SAPF nonlinear control method based on a Lyapunov function. Background technique [0002] In recent years, with the widespread use of rectification and frequency conversion devices and the rapid increase of semiconductor nonlinear loads, the power system is facing more and more serious harmonic pollution problems. Using shunt active power filter (Shunt Active PowerFilter, SAPF) for dynamic real-time compensation of power grid harmonics has become one of the most effective and promising approaches. [0003] Compared with the traditional two-level SAPF, the three-level SAPF has many advantages, such as lower switching frequency and loss, high system withstand voltage, and application in higher voltage systems. The topology of three-level SAPF mainly includes diode clamped (Neutral-Point Clamped, NPC) type, flying capacitor type and cascaded H-...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02J3/01H02J3/18H02M7/487
CPCH02J3/01H02J3/1842H02J2203/20H02M7/487Y02E40/30Y02E40/40
Inventor 程启明张宇谭冯忍高杰余德清陈路李涛孙伟莎程尹曼
Owner SHANGHAI UNIVERSITY OF ELECTRIC POWER
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