High-power active power filter

Abstract

The utility model relates to a high-power active power filter based on parallel connection of single-tube IGBTs, which comprises an instruction current operational circuit and a compensation current generating circuit, and is characterized in that the compensation current generating circuit comprises a plurality of IGBT assemblies, the instruction current operational circuit controls the IGBT assemblies to be opened and closed, and each IGBT assembly comprises a plurality of single-tube IGBTs which are connected in parallel. The beneficial effects are that first, the circuit cost is reduced; secondly, the installation and the assembly are simple and convenient; and thirdly, the IGBTs connected in parallel are independent, and if one IGBT is damaged, the operation of the machine is not influenced. And fourthly, maintenance is convenient.

Description

TECHNICAL FIELD

[0001] The utility model belongs to active power filter field, especially relates to a kind of high-power active power filter based on single tube IGBT parallel connection. BACKGROUND

[0002] Active power filter is a new type of power harmonic control special equipment made of modern power electronics technology and digital signal processing technology based on high-speed DSP device.It is composed of two main parts of instruction current operation circuit and compensation current generating circuit.Instruction current operation circuit monitors current in line in real time, and converts analog current signal into digital signal, which is sent to high-speed digital signal processor (DSP) for signal processing, separates harmonic from fundamental wave, and sends out driving pulse in the form of pulse width modulation (PWM) signal to compensation current generating circuit to drive IGBT or IPM power module, generates compensation current with equal amplitude and opposite polarity of grid harmonic current, compensates or offsets harmonic current, and actively eliminates power harmonic.Most of the high-power active power filters used in the market adopt IGBT module, but IGBT module is high in cost and difficult to repair after damage.In addition, most of the high-power active power filters adopt IGBT module parallel connection, which is also troublesome in installation welding.Therefore, a low-cost, easy-to-repair and easy-to-install high-power active power filter is needed in the prior art. SUMMARY

[0003] The utility model provides a kind of low-cost, easy-to-repair, easy-to-install high-power active power filter, including instruction current operation circuit and compensation current generating circuit, it is characterized in that, the compensation current generating circuit includes several IGBT components, the instruction current operation circuit controls the IGBT component opening and closing, and each IGBT component includes several parallel single tube IGBT.

[0004] Further high-power active power filter, each single tube IGBT is detachably mounted on PCB.

[0005] Further high-power active power filter, the single tube IGBT is: manufacturer INFINEON TECHNOLOGIES, model IKW75N65EH5_B11 or macro micro: MM75G3T65B.

[0006] Further high-power active power filter, the compensation current generating circuit is I type three-level topology structure.

[0007] Further, the large power active power filter, each IGBT component includes 3-9 parallel single tube IGBT, each of the active power filter uses 12-36 single tube IGBT, the utility model discloses a purpose to the large power active power filter of IGBT module parallel on the market, develops a kind of active power filter of IGBT single tube parallel mode, its beneficial effect is that: first, circuit cost is reduced;Second, installation assembly also becomes simple;Third, parallel IGBT is independent, if there is a IGBT breakdown case, it does not affect the operation of machine.Fourth, it is convenient to repair. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 It is the schematic diagram of exemplary APF in prior art.

[0009] Figures 2 to 5 It is the schematic diagram of commutation circuit of APF based on I type three levels.

[0010] Figure 6 It is the schematic diagram of large power active power filter based on single tube IGBT parallel.

[0011] Figure 7 IGBT module welding \ single tube welding schematic diagram (wherein, Figure 7 a. it is IGBT module welding point picture; Figure 7 b. it is single tube IGBT welding point picture; Figure 7 c. single tube IGBT installation position). DETAILED DESCRIPTION

[0012] The embodiments of the present application will be described in detail below with reference to the accompanying drawings and examples.

[0013] Active power filter (APF) is based on IGBT power changer for dynamic filtering harmonic, dynamic compensation reactive power power electronic device.APF real-time detection in power grid each harmonic and reactive power, and carries out dynamic tracking compensation, therefore can compensate the harmonic and the reactive power of change of amplitude and frequency both change.The basic principle of APF of the utility model is not specifically limited, for example, the APF of some embodiments is through external mutual inductor CT real-time acquisition current signal, through internal detection circuit separates the harmonic part therein, through IGBT power changer generates the compensation current of harmonic size equal phase opposite in system, realizes the function of filtering harmonic.

[0014] In some specific embodiments, in combination Figure 1As shown, the APF is connected between the power grid end and the load end, and the current signal is collected through a primary measuring transformer.The compensation current generating circuit of the APF comprises a circuit breaker, an inductor, a contactor, a current sensor, an IGBT topological circuit, a voltage sensor, a DC side capacitor, and the instruction current operation circuit comprises a control board, a voltage circuit sampling, a slave board and a display board.It should be noted that only the IGBT topological circuit is improved in the utility model, and other known APFs or slightly modified APFs can also be applied to the IGBT topological circuit of the utility model.

[0015] In some embodiments of the low-cost, easy-to-maintain, easy-to-install high-power active power filter, the instruction current operation circuit and the compensation current generating circuit are provided, the compensation current generating circuit comprises a plurality of IGBT components, and the instruction current operation circuit controls the IGBT components to open and close, and each IGBT component comprises a plurality of parallel single-tube IGBTs.Most of the existing high-power active power filters adopt the parallel mode of IGBT modules, which is also relatively troublesome in the process of installation and welding, because the IGBT module is welded, manual welding or spot welding is required, which is time-consuming and labor-intensive;the single-tube welding of the present application directly uses a tin furnace for welding, which saves time and labor. Figure 7 For a PCB board example, it cannot be used as a limitation of the scope of protection of the patent. Figure 7 As shown in a, the pin of two IGBT modules in the red frame (A1, A2) is 68 welding points, which is limited by installation and can only be manually welded with an iron or welded with a machine, which is time-consuming. Figure 7 As shown in b, the pin of 12 single-tube IGBTs in the red frame (B1, B2, B3, B4) is 36 welding points, which can be directly wave soldered, saving time. Figure 7 C is the installation mode of the single-tube IGBT, which is locked on the heat sink and then inserted into the circuit board for welding.

[0016] In some embodiments of the high-power active power filter, each single-tube IGBT is detachably mounted on the PCB board.

[0017] In some embodiments of the high-power active power filter, the single-tube IGBT is: manufacturer NFINEON TECHNOLOGIES, model IKW75N65EH5_B11 or macro micro: MM75G3T65B.

[0018] In some embodiments of the high-power active power filter, the compensation current generating circuit is an I-type three-level topological structure. Figure 2As shown, the embodiment provides a type I three-level topology, using single-tube IGBT and fast recovery diode to build three-level topology, through driving signal DRIVG1, DRIVG2, DRIVG3, DRIVG4 to realize the control of IGBT turn-on and turn-off, thereby realizing the output of current, and the following introduces a period of commutation loop (assuming the current flows inward). By Figure 3 As shown, the circuit is simplified for easy description. The states of DRIVG1, DRIVG2, DRIVG3, and DRIVG4 are represented by 1 and 0, respectively, 1 represents high level, and 0 represents low level. When DRIVG1 is high level, IGBT modules Q1, Q2, and Q3 are turned on at the same time. When DRIVG1 is low level, IGBT modules Q1, Q2, and Q3 are turned off at the same time.

[0019] 1. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 1100, the current flows from the load through the body diode of IGBT module T1 / T2 to the DC+ end of the capacitor, as shown in Figure 3 .

[0020] 2. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 0100, the current flows through the same path, that is, through the body diode of IGBT module T1 / T2 to the DC+ end of the capacitor, as shown in Figure 3 .

[0021] 3. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 0110, the current path changes, and the current flows from the load through IGBT module T3 and D6 to the center point 0 of the capacitor, as shown in Figure 4 .

[0022] 4. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 0010, the current flows through the same path, that is, through IGBT module T3 and D6 to the center point 0 of the capacitor, as shown in Figure 4 .

[0023] 5. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 0011, the current flows from the load through IGBT module T3 / T4 to the DC- end of the capacitor, as shown in Figure 5 .

[0024] 6. When the states of Drive 1, Drive 2, Drive 3, and Drive 4 are 0010, the current flows from the load through IGBT module T3 and D6 to the center point of the capacitor, as shown inFigure 3 as shown.

[0025] 7. When the state of Drive 1, Drive 2, Drive 3, Drive 4 is 0110, the current flows from the load through IGBT module T3 and D6 to the midpoint of the capacitor, as shown. Figure 4

[0026] 8. When the state of Drive 1, Drive 2, Drive 3, Drive 4 is 0100, the current flows from the load through the body diode of IGBT module T1 / T2 to the DC+ end of the capacitor, as shown. Figure 3

[0027] In some embodiments, each IGBT component includes 3-9 parallel single tube IGBTs, and each said active power filter uses 12-36 single tube IGBTs. In some embodiments, the principle of the high-power active power filter is shown in Figure 6 as a type I three-level topology, including 12 single tube IGBTs, and each IGBT component includes 3 parallel single tube IGBTs.

[0028] The above-described embodiments are merely preferred embodiments of the present application, and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the scope of protection of the claims of the present application.​​

Claims

1. A high-power active power filter comprising a command current operation circuit and a compensation current generation circuit, characterized by, The compensation current generating circuit comprises a plurality of IGBT components, and the instruction current calculating circuit controls the opening and closing of the IGBT components.

2. The high-power active power filter of claim 1, wherein, Each single-tube IGBT is detachably mounted on a PCB board.

3. The high-power active power filter of claim 2, wherein, The single-tube IGBT is of a factory NFINEON TECHNOLOGIES and a model IKW75N65EH5_B11 or a macro-micro MM75G3T65B.

4. The high-power active power filter of claim 3, wherein, The compensation current generating circuit is of an I-type three-level topology structure.

5. The high-power active power filter of claim 4, wherein, Each IGBT component comprises 3-9 single-tube IGBTs in parallel, and each active power filter uses 12-36 single-tube IGBTs.

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