Novel power quality controller based on current-mode inverter and control method thereof

Abstract

The invention relates to a novel power quality controller based on a current type inverter and a control method thereof. The technical characteristics are that the novel power quality controller comprises an energy storage inductor, an inverter circuit, a low-pass filter circuit and a connection inductance unit. The energy storage inductor is connected with the inverter circuit and used for providing inverter DC side current. The inverter circuit is used for generating AC current required for regulating the power quality and charging the energy storage inductor. The inverter circuit is connected with the low-pass filter circuit and used for filtering the high-order harmonics in the output PWM current of the inverter circuit. The connection inductance unit is connected in series between a power supply and a load and used for generating a bias voltage required for compensating the load voltage. The novel power quality controller is simple in structure and convenient to control.

Description

technical field [0001] The invention belongs to the technical field of electrical automation, and relates to a control method of a three-port integrated power quality regulator, in particular to a new power quality controller based on a current-type inverter and a control method thereof. Background technique [0002] With the development of modern science and technology, power quality problems become more and more significant. At present, the problem of power quality is mainly reflected in two aspects. On the one hand, abnormal power supply voltage has a serious adverse effect on some sensitive users. On the other hand, with the rapid development of power electronics technology and the wide application of power converter devices, the There are more and more nonlinear and impact loads in the system, and most of them are inductive loads, which lead to power quality problems such as harmonics, low power factor, voltage fluctuation, flicker, and three-phase unbalance. In respon...

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Problems solved by technology

[0004] Due to the structural characteristics of the parallel three-port power quality conditioner, there is a significant problem in its control strategy. For example, the PI plus feedforward compensation decoupling control method based on the state model in the d and q coordinate system is generally used at present. Since the power supply and the load are only connected through an inductance, when the power supply voltage drops, the load voltage can quickly return to the rated value, which is approximately equivalent to a sudden change in the voltage at both ends of the connected reactor. During the current transition process of the connected inductance , because there is no series resistor on the inductor branch, the transient component of the inductor current does not attenuate. Although the line itself has a certain resistance in the actual system, the resistance value is too small to cause the transient component to decay in a short time, so that There is a strong DC component in this current

Obviously, the most direct solution is to connect a large enough resistor in series with the power supply DC to accelerate the attenuation of the transient component of the power supply current. It will cause a lot of loss and seriously affect the efficiency of the system, so it is not advisable

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