CN219717885U

CN219717885U - Current transformer busbar energy bleeder circuit

Info

Publication number: CN219717885U
Application number: CN202321311708.XU
Authority: CN
Inventors: 谢峰; 李晶惠; 罗祖林; 李海明
Original assignee: Heyuan Hewang Electric Co ltd
Current assignee: Heyuan Hewang Electric Co ltd
Priority date: 2023-05-25
Filing date: 2023-05-25
Publication date: 2023-09-19
Anticipated expiration: 2033-05-25

Abstract

The utility model discloses a converter bus energy bleeder circuit, which comprises a machine side converter and a net side converter, wherein the machine side converter and the net side converter are connected together through the converter bus energy bleeder circuit, the wind power converter bus energy bleeder circuit comprises a converter positive bus, a converter negative bus, a control unit L1, a direct current bus capacitor C1, a depletion type MOSFET (metal oxide semiconductor field effect transistor) and a discharge resistor R1, the drain electrode of the depletion type MOSFET is connected with the converter positive bus, the source electrode of the depletion type MOSFET is connected with one end of a discharge resistor R, the other end of the discharge resistor R is connected with the converter negative bus, and the direct current bus capacitor C1 is connected between the converter positive bus and the converter negative bus; the converter bus energy bleeder circuit improves the system efficiency, discharges without improving the ambient temperature beside the bus capacitor, avoids damaging devices, and can still discharge after the system is powered off.

Description

Current transformer busbar energy bleeder circuit

Technical Field

The utility model relates to the technical field of converters, in particular to a converter bus energy bleeder circuit.

Background

In recent years, with the continuous development of the power electronics industry, the power of power electronics equipment is also increasing, and current converters such as wind power converters, frequency converters, photovoltaic inverters and the like commonly used at present are provided with direct current buses. The direct current bus generally adopts a high-power capacitor as an energy storage element, and the energy stored in the direct current capacitor needs to be rapidly discharged after the system is stopped. The general discharging method is thus that fig. 1 and 2, fig. 1 is to add a resistor between the dc buses for bus discharging, and fig. 2 is to discharge via a contactor and resistor at both ends of the bus.

However, both the two direct current bus discharging circuits have certain instability, and the direct current bus discharging circuit shown in fig. 1 has certain consequences if the resistance value is improperly selected, and has too high discharging speed if the resistance value is excessively selected, but has too high cost; if the resistance value of the resistor is too small, large power consumption and heat can be generated, the system efficiency can be reduced, and surrounding devices can be damaged. In the direct current bus discharging circuit with the resistor of the contactor shown in fig. 2, when certain power consumption and heat are generated on the discharging resistor, the phenomenon of adhesion of the contactor is caused, so that the system efficiency is reduced, the ambient temperature beside a bus capacitor is increased, and the device is easily damaged.

The chinese patent CN216959652U discloses a wind power converter, a chopper bleeder circuit and a driving circuit thereof, as shown in fig. 3, the switching tube used is an IGBT, the turn-on and turn-off of the IGBT is controlled mainly by the system to send out a high-low level driving signal, and in general, the IGBT is turned on at a high level and turned off at a low level, so it can be seen that the discharging circuit of fig. 3 is turned on when the system sends out a high level driving signal, the bus can be discharged, that is, the discharging circuit must be turned on when the system is powered on, but the discharging circuit does not necessarily be turned on after the system is powered off, so if the discharging operation needs to be performed after the system is powered off, the scheme cannot be completed.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a converter bus energy bleeder circuit, which improves the system efficiency, discharges without improving the ambient temperature beside a bus capacitor, avoids damaging devices, and can still discharge after the system is powered off.

In order to solve the technical problems, the utility model provides a converter busbar energy bleeder circuit, which comprises a machine side converter and a net side converter, wherein the machine side converter and the net side converter are connected together through the converter busbar energy bleeder circuit, the converter busbar energy bleeder circuit comprises a converter positive busbar, a converter negative busbar, a control unit L1, a direct current busbar capacitor C1, a depletion type MOSFET Q1 and a discharge resistor R1, the drain electrode of the depletion type MOSFET Q1 is connected with the converter positive busbar, the source electrode of the depletion type MOSFET Q1 is connected with one end of the discharge resistor R, the other end of the discharge resistor R is connected with the converter negative busbar, and the direct current busbar capacitor C1 is connected between the converter positive busbar and the converter negative busbar; the converter bus energy release circuit comprises a control unit used for detecting the real-time running state of a converter system and sending a high-level driving signal when a restarting instruction arrives after the fault shutdown or self shutdown, and the grid electrode of the depletion type MOSFET Q1 is connected with the driving signal output end of the control unit.

Preferably, the depletion MOSFET Q1 is a switching transistor that does not apply any gate voltage and current flows from the drain terminal to the source when connected on.

Preferably, the depletion MOSFET Q1 and the discharge resistor R1 form a discharge loop when the converter system fails or shuts down.

Preferably, the converter is a wind power converter or a frequency converter.

After the circuit is adopted, the converter bus energy bleeder circuit comprises a converter positive bus, a converter negative bus, a control unit L1, a direct current bus capacitor C1, a depletion MOSFET Q1 and a discharge resistor R1, wherein the drain electrode of the depletion MOSFET Q1 is connected with the converter positive bus, the source electrode of the depletion MOSFET Q1 is connected with one end of the discharge resistor R, the other end of the discharge resistor R is connected with the converter negative bus, and the direct current bus capacitor C1 is connected between the converter positive bus and the converter negative bus; the converter bus energy release circuit comprises a control unit, a power supply unit and a power supply unit, wherein the control unit is used for detecting the real-time running state of a converter system and sending a high-level driving signal when a restarting instruction arrives after a fault shutdown or self shutdown, and the grid electrode of the depletion type MOSFET Q1 is connected with the driving signal output end of the control unit; the converter bus energy bleeder circuit improves the system efficiency, discharges without improving the ambient temperature beside the bus capacitor, avoids damaging devices, and can still discharge after the system is powered off.

Drawings

FIG. 1 is a prior art DC bus discharge circuit diagram I;

FIG. 2 is a schematic diagram of a prior art DC bus discharge circuit;

FIG. 3 is a prior art DC bus discharge circuit diagram III;

fig. 4 is a diagram of an energy bleed circuit of a current transformer bus of the present utility model.

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear and obvious, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In the description of the present utility model, it should be understood that the directions or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

Referring to fig. 4, fig. 4 is a schematic diagram of an energy discharging circuit of a bus of a converter according to the present utility model;

the embodiment discloses a converter bus energy bleeder circuit, wherein the converter comprises a converter side converter and a grid side converter, the converter side converter and the grid side converter are connected together through the converter bus energy bleeder circuit, the converter bus energy bleeder circuit comprises a converter positive bus 12, a converter negative bus 13, a control unit L1, a direct current bus capacitor C1, a depletion type MOSFET Q1 and a discharge resistor R1, the drain electrode of the depletion type MOSFET Q1 is connected with the converter positive bus, the source electrode of the depletion type MOSFET Q1 is connected with one end of the discharge resistor R, the other end of the discharge resistor R is connected with the converter negative bus 13, and the direct current bus capacitor C1 is connected between the converter positive bus 12 and the converter negative bus 13; the converter bus energy release circuit comprises a control unit 11 which is used for detecting the real-time running state of the converter system and sending a high-level driving signal when a restarting instruction arrives after the fault shutdown or self shutdown state, and the grid electrode of the depletion type MOSFET Q1 is connected with the driving signal output end of the control unit 11.

Example two

This embodiment is based on the first embodiment, which, in this embodiment,

when the control unit detects that the system is in a normal working state, the control unit sends out high-level drive to the depletion type MOSFET Q1, and at the moment, the depletion type MOSFET is turned off, a system discharging loop is disconnected, and discharging operation is not carried out.

When the control unit detects that the system is in a normal shutdown state or a fault shutdown state, the control unit 11 does not send a driving signal to the depletion type MOSFET Q1, and when the depletion type MOSFET Q1 does not receive the driving signal or the driving signal is in a low level, the depletion type MOSFET is conducted at the moment, a system discharge loop is communicated, and a discharge operation is started.

When the converter system is in fault stop or self stop, the depletion type MOSFET Q1 and the discharge resistor R1 form a discharge loop.

Example III

The present embodiment is based on the first embodiment, in which the depletion MOSFET Q1 is a switching transistor that is turned on and connected without applying any gate voltage and current flows from the drain terminal to the source.

Example IV

The present embodiment is based on the first embodiment, and in this embodiment, the converter is a wind power converter or a frequency converter.

The preferred embodiments of the present utility model have been described above with reference to the accompanying drawings, and thus do not limit the scope of the claims of the present utility model. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the present utility model shall fall within the scope of the appended claims.

Claims

1. The converter bus energy bleeder circuit is characterized by comprising a converter side converter and a grid side converter, wherein the converter side converter and the grid side converter are connected together through the converter bus energy bleeder circuit, the converter bus energy bleeder circuit comprises a converter positive bus, a converter negative bus, a control unit L1, a direct current bus capacitor C1, a depletion MOSFET Q1 and a discharge resistor R1, the drain electrode of the depletion MOSFET Q1 is connected with the converter positive bus, the source electrode of the depletion MOSFET Q1 is connected with one end of the discharge resistor R, the other end of the discharge resistor R is connected with the converter negative bus, and the direct current bus capacitor C1 is connected between the converter positive bus and the converter negative bus; the converter bus energy release circuit comprises a control unit used for detecting the real-time running state of a converter system and sending a high-level driving signal when a restarting instruction arrives after the fault shutdown or self shutdown, and the grid electrode of the depletion type MOSFET Q1 is connected with the driving signal output end of the control unit.

2. The converter bus energy bleed circuit of claim 1, wherein the depletion MOSFET Q1 is a switching tube that does not apply any gate voltage and current flows from the drain terminal to the source when connected on.

3. The converter bus energy bleed circuit of claim 1, wherein the depletion MOSFET Q1 forms a discharge loop with a discharge resistor R1 when the converter system fails to shut down or self-shuts down.

4. The converter busbar energy bleed circuit of claim 1, wherein the converter is a wind power converter or a frequency converter.