CN212784780U

CN212784780U - Active power filter based on two-level branch circuit parallel connection

Info

Publication number: CN212784780U
Application number: CN202021274280.2U
Authority: CN
Inventors: 毕平劲; 蒋绍涛; 李新初
Original assignee: Wuhan Xinkaiyuan Electronics Co ltd
Current assignee: Wuhan Xinkaiyuan Electronics Co ltd
Priority date: 2020-07-02
Filing date: 2020-07-02
Publication date: 2021-03-23
Anticipated expiration: 2030-07-02

Abstract

The utility model discloses an active power filter based on two-level branch circuit parallel connection, the power is connected with nonlinear load, the three-phase line of the power is connected with the fuse through the breaker, the fuse is connected with one end which is respectively connected with a first charging circuit, a second charging circuit and a high-frequency filter loop through the network side inductor; the first current Hall sensor is connected with a zero line of a power supply through a first two-level IGBT module branch, and the second current Hall sensor is connected with the zero line of the power supply through a second two-level IGBT module branch. The utility model discloses beneficial effect: the utility model discloses first two-level IGBT module branch road is parallelly connected with second two-level IGBT module branch road, adopts the carrier wave to move the phase mode in control, can offset partial high frequency ripple and higher harmonic mutually between two parallelly connected bridge arms, realizes three level forms on the output waveform, has obtained more multistage output voltage for the output waveform more is close to the sine wave, and harmonic content is few, and voltage change rate is little, and output capacity is big.

Description

Active power filter based on two-level branch circuit parallel connection

Technical Field

The utility model belongs to the technical field of the active power filter technique of APF and specifically relates to an active power filter based on two level branch roads are parallelly connected.

Background

The APF active power filter can complete harmonic compensation, power factor compensation and three-phase unbalance compensation, carries out comprehensive management on the electric energy quality of a power grid, and is mainly used in a device range with system voltage not exceeding 1 KV.

In order to increase the equipment capacity of the APF active filter device, the IGBT capacity is generally increased or the IGBT is directly connected in parallel. For the scheme, the limitations of capacity limitation, great cost improvement, low operation reliability and the like of the conventional device model selection exist. The two-level IGBT module has the advantages of simple structure, high power density, relatively low cost and the like, but the APF active filter device directly adopts two-level output, and the defects of high filter inductance, high output harmonic and the like exist due to few output level steps.

Therefore, it is necessary to provide an active power filter based on parallel connection of two-level branches to solve the above problems.

SUMMERY OF THE UTILITY MODEL

To the not enough of existence among the above-mentioned prior art, the utility model aims to provide an active power filter based on two level branch roads are parallelly connected to solve above-mentioned problem.

An active power filter based on two-level branch circuit parallel connection comprises a power supply, a circuit breaker, a fuse, a network side inductor, a first charging circuit, a second charging circuit, a first current Hall sensor, a second current Hall sensor, a first two-level IGBT module branch circuit, a second two-level IGBT module branch circuit and a high-frequency filter circuit, wherein the power supply is connected with a nonlinear load through a three-phase line and a zero line, the three-phase line of the power supply is connected with the fuse through the circuit breaker, and the fuse connection is respectively connected with one end of the first charging circuit, the second charging circuit and the high-frequency filter circuit through the network side inductor; the first current Hall sensor is connected with a zero line of the power supply through a first two-level IGBT module branch, and the second current Hall sensor is connected with the zero line of the power supply through a second two-level IGBT module branch.

The circuit breaker and the fuse play a role in protecting a circuit, and the network side inductor can play a role in equalizing current between the two modules; the high-frequency filtering loop is used for completing the filtering function of the switching frequency; the first two-level IGBT module branch and the second two-level IGBT module branch are controlled by the driving circuit to finish the power change and current output functions.

Preferably, a first bridge side inductor is connected between the first current hall sensor and the first two-level IGBT module branch.

Preferably, a second bridge side inductor is connected between the second current hall sensor and the second two-level IGBT module branch.

The beneficial effects of the preferable technical scheme are as follows: the first bridge side inductor and the second bridge side inductor play a role in smoothing and filtering.

Preferably, a first direct current supporting capacitor is connected between the first two-level IGBT module branch and a zero line of the power supply.

Preferably, a second direct current support capacitor is connected between the second two-level IGBT module branch and a zero line of the power supply.

The beneficial effects of the preferable technical scheme are as follows: the first DC support capacitor and the second DC support capacitor provide DC voltage on the inverting side.

Preferably, the first charging circuit includes a first main circuit switch and a first charging resistor, and the first main circuit switch is connected in parallel with the first charging resistor.

Preferably, the second charging circuit includes a second main circuit switch and a second charging resistor, and the second main circuit switch is connected in parallel with the second charging resistor.

The beneficial effects of the preferable technical scheme are as follows: the first charging circuit and the second charging circuit play a role of soft power-on.

Compared with the prior art, the utility model discloses beneficial effect: the utility model discloses first two-level IGBT module branch road is parallelly connected with second two-level IGBT module branch road, adopts the carrier wave to move the phase mode in control, can offset partial high frequency ripple and higher harmonic mutually between two parallelly connected bridge arms, realizes three level forms on the output waveform, has obtained more multistage output voltage for the output waveform more is close to the sine wave, and harmonic content is few, and voltage change rate is little, and output capacity is big.

Drawings

Fig. 1 is a schematic diagram of an active power filter circuit based on parallel connection of two-level branches according to the present invention;

FIG. 2 is a waveform diagram of the two-level branch output of the present invention;

fig. 3 is an output waveform diagram of the APF device of the present invention.

Reference numbers in the figures: 1. a first charging circuit; 2. a second charging circuit; QF, breaker; FU and a fuse; l1, net side inductance; LC, high-frequency filtering loop; k1, a first main circuit switch; k2, a second main circuit switch; r1, a first charging resistor; r2, a second charging resistor; TA1, first current hall sensor; TA2, second current hall sensor; l2, a first bridge-side inductance; l3, a second bridge-side inductance; q1, a first two-level IGBT module branch circuit; q2 and a second two-level IGBT module branch circuit; c1, a first DC support capacitor; c2, and a second direct current support capacitor.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

As shown in fig. 1 in combination with fig. 2 to 3, an active power filter based on two-level branch parallel connection includes a power supply, a circuit breaker QF, a fuse FU, a grid-side inductor L1, a first charging circuit 1, a second charging circuit 2, a first current hall sensor TA1, a second current hall sensor TA2, a first two-level IGBT module branch Q1, a second two-level IGBT module branch Q2, and a high-frequency filter circuit LC, wherein the power supply is connected with a nonlinear load through a three-phase line and a zero line, the three-phase line of the power supply is connected with the fuse FU through the circuit breaker QF, and the fuse FU is connected with one end of the first charging circuit 1, the second charging circuit 2, and the high-frequency filter circuit LC through a grid-side inductor L1; the first current Hall sensor TA1 is connected with the zero line of the power supply through a first two-level IGBT module branch Q1, and the second current Hall sensor TA2 is connected with the zero line of the power supply through a second two-level IGBT module branch Q2.

The circuit breaker QF and the fuse FU play a role in protecting a circuit, and the grid side inductor L1 can play a role in equalizing current between the two modules; the high-frequency filtering circuit LC completes the filtering function of the switching frequency; the first two-level IGBT module branch Q1 and the second two-level IGBT module branch Q2 are controlled by a driving circuit to complete power change and current output functions.

Further, a first bridge-side inductor L2 is connected between the first current hall sensor TA1 and the first two-level IGBT module branch Q1.

Further, a second bridge-side inductor L3 is connected between the second current hall sensor TA2 and the second two-level IGBT module branch Q2.

The beneficial effects of the further technical scheme are that: the first bridge side inductor L2 and the second bridge side inductor L3 play a role in smoothing and filtering.

Further, a first direct current supporting capacitor C1 is connected between the first two-level IGBT module branch Q1 and a zero line of the power supply.

Further, a second direct-current supporting capacitor C2 is connected between the second two-level IGBT module branch Q2 and a zero line of the power supply.

The beneficial effects of the further technical scheme are that: the first dc support capacitor C1 and the second dc support capacitor C2 provide dc voltages on the inverting side.

Further, the first charging circuit 1 includes a first main circuit switch K1 and a first charging resistor R1, and the first main circuit switch K1 is connected in parallel with the first charging resistor R1.

Further, the second charging circuit 2 includes a second main circuit switch K2 and a second charging resistor R2, and the second main circuit switch K2 is connected in parallel with the second charging resistor R2.

The beneficial effects of the further technical scheme are that: the first charging circuit 1 and the second charging circuit 2 play a role of soft power-on.

Compared with the prior art, the utility model discloses beneficial effect: the utility model discloses first two-level IGBT module branch road Q1 is parallelly connected with second two-level IGBT module branch road Q2, adopts the carrier wave to move the phase mode in control, can offset partial high frequency ripple and higher harmonic each other between two parallelly connected bridge arms, realizes three level forms on the output waveform, has obtained more multistage output voltage for the output waveform more is close to the sine wave, and harmonic content is few, and the voltage change rate is little, and output capacity is big.

The first two-level IGBT module branch Q1 and the second two-level IGBT module branch Q2 are formed by connecting six IGBT modules (insulated gate bipolar transistors).

The device adopts a branch parallel connection scheme of a two-level IGBT module, and can realize all the performances of the three-phase three-level active power filter. And simultaneously, the utility model provides a novel topological structure easily is used in multilevel dc-to-ac converter such as five levels, when improving power electronic device capacity, the cost is reduced. Compared with the traditional two-level active power filter, the topological active power filter has the advantages of small output voltage harmonic, reduction of required filter inductance, high efficiency, contribution to reduction of equipment volume and reduction of system cost and loss.

The working principle is as follows: the device is connected with a power grid in parallel, harmonic current components, reactive current components and asymmetric current components which need to be compensated are calculated by accurately sampling and analyzing the current of a nonlinear load and the current of two branches of the body, the control circuit and the driving circuit transmit output instructions to the two branches consisting of the device 8 and the device 15, the output current of the branches is the current of the power grid which needs to be compensated, and the requirement of an active power filter on power quality control of the power grid is met; adjusting the phase shift angle of two branches by carrier phase shifting SPWM (CPS-SPWM) and other modes, synthesizing two level waveforms of a single branch into a three level waveform accessed to a power grid, wherein the output waveform of the single branch is shown in FIG. 2; the synthesized output waveform of the APF device is shown in fig. 3, which makes the output waveform closer to a sine wave, and has less harmonic content, small voltage change rate and large output capacity.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims

1. The utility model provides an active power filter based on two level branch road are parallelly connected which characterized in that: the power supply comprises a power supply, a circuit breaker (QF), a Fuse (FU), a grid side inductor (L1), a first charging circuit (1), a second charging circuit (2), a first current Hall sensor (TA1), a second current Hall sensor (TA2), a first two-level IGBT module branch (Q1), a second two-level IGBT module branch (Q2) and a high-frequency filter Loop (LC), wherein the power supply is connected with a nonlinear load through a three-phase line and a zero line, the three-phase line of the power supply is connected with the Fuse (FU) through the circuit breaker (QF), and the Fuse (FU) is connected with one ends of the first charging circuit (1), the second charging circuit (2) and the high-frequency filter Loop (LC) through the grid side inductor (L1); the first current Hall sensor (TA1) is connected with a zero line of a power supply through a first two-level IGBT module branch circuit (Q1), and the second current Hall sensor (TA2) is connected with the zero line of the power supply through a second two-level IGBT module branch circuit (Q2).

2. An active power filter based on two-level branch parallel connection according to claim 1, characterized in that: a first bridge side inductor (L2) is connected between the first current Hall sensor (TA1) and the first two-level IGBT module branch (Q1).

3. An active power filter based on two-level branch parallel connection according to claim 2, characterized in that: and a second bridge side inductor (L3) is connected between the second current Hall sensor (TA2) and the second two-level IGBT module branch circuit (Q2).

4. An active power filter based on two-level branch parallel connection according to claim 3, characterized in that: and a first direct current supporting capacitor (C1) is connected between the first two-level IGBT module branch circuit (Q1) and a zero line of the power supply.

5. An active power filter based on two-level branch parallel connection according to claim 4, characterized in that: and a second direct current supporting capacitor (C2) is connected between the second two-level IGBT module branch circuit (Q2) and a zero line of the power supply.

6. An active power filter based on two-level branch parallel connection according to claim 5, characterized in that: the first charging circuit (1) comprises a first main circuit switch (K1) and a first charging resistor (R1), the first main circuit switch (K1) being connected in parallel with the first charging resistor (R1).

7. An active power filter based on two-level branch parallel connection according to claim 6, characterized in that: the second charging circuit (2) comprises a second main circuit switch (K2) and a second charging resistor (R2), the second main circuit switch (K2) being connected in parallel with the second charging resistor (R2).