CN212258836U - Driving device for IGBT (insulated Gate Bipolar transistor) of frequency converter - Google Patents

Abstract

The utility model discloses a drive arrangement (100) for converter IGBT. The driving device (100) comprises a driving board (101) which is configured to receive an electric signal output by a frequency conversion system and process the electro-optical signal for output after isolation and amplification, and is characterized in that the driving device (100) further comprises an adapter board (102), and the adapter board (102) is configured to receive and process the electric signal processed by the driving board (101) so as to drive the on or off of one or more IGBTs. The utility model discloses can increase IGBT's conduction current on the basis that not increase equipment cost by a wide margin to supply power to the motor of higher power, satisfied the user demand of motor.

Description

Driving device for IGBT (insulated Gate Bipolar transistor) of frequency converter

Technical Field

The present invention relates generally to motor applications. More specifically, the utility model relates to a drive arrangement for converter IGBT.

Background

At present, the rotation speed of the motor is required to have variability under different application scenarios, so the motor is generally powered by a frequency converter, and most of inverter bridge parts in the frequency converter adopt a circuit composed of Insulated Gate Bipolar transistors ("IGBTs"). In general, for a low-power motor, only one driving plate is needed to drive one low-voltage IGBT by an upper bridge or a lower bridge of an inverter bridge, so that the requirement of the motor on driving current can be met. However, as a motor with higher power is required in different application scenarios, the driving mode described above is gradually unable to meet the requirement of a high-power motor, and therefore, the current conducting capability of the IGBT needs to be increased.

Currently, there are two methods to increase the current intensity flowing through the IGBT. On the one hand, the IGBT with high voltage and strong loading capacity can be adopted, and for example, finished IGBT modules of manufacturers such as Sammy controllers can be directly purchased. Although the stability of the product can be improved, the price of the IGBT with one grade of voltage is increased by times, so that the cost is increased greatly by selecting the high-voltage IGBT with strong loading capacity. On the other hand, the current passing strength of the parallel-connected IGBTs can be increased by adopting a mode of parallel connection of a plurality of IGBTs, and the cost can be obviously reduced. However, after a plurality of IGBTs are connected in parallel, difficulties such as dynamic, static current sharing, radiation interference and the like occur, which requires that the performance of the selected IGBT module is stable and the layout of the driving circuit is reasonable so as to equalize the current intensity distributed to each IGBT. Meanwhile, a plurality of parallel IGBTs are required to be simultaneously switched on and off, otherwise the IGBTs may be burnt, and irretrievable results are caused.

SUMMERY OF THE UTILITY MODEL

To solve at least one or more of the problems of the background art described above, and to provide an IGBT driving circuit of a motor inverter capable of satisfying a high power demand. The utility model provides a IGBT drive arrangement, on the basis of current IGBT drive plate, increased the adapter plate that can drive a plurality of parallelly connected IGBTs simultaneously. Under the drive of the adapter plate, current uniformly flows through each IGBT, and the parallel IGBTs can be controlled to be switched on or switched off simultaneously, so that the aim of increasing the current intensity of the alternating current output by the inverter bridge is fulfilled, and a motor with higher power can be supplied with power.

Specifically, the utility model discloses a drive arrangement for converter IGBT, this circuit board include the drive plate, and its configuration is used for receiving the signal of telecommunication of frequency conversion system output, and will the signal of telecommunication is handled so that export after isolation and amplification, its characterized in that drive arrangement still includes one or more adapter plate, the adapter plate configuration is used for receiving and handles the process the signal of telecommunication after the drive plate is handled, so that be used for the drive switch on or turn-off of IGBT.

In one embodiment, the driving plate of the driving device of the present invention includes a photoelectric coupler configured to photoelectrically convert an electric signal output from the frequency conversion system so as to electrically isolate the frequency conversion system from the driving device.

In another embodiment, the driving plate of the driving device of the present invention further includes an amplifying circuit configured to amplify the electrical signal output by the photoelectric coupler so as to output the electrical signal to the adapter plate.

In yet another embodiment, the adapter board of the driving device of the present invention comprises a circuit of a resistor, a capacitor and a diode, so as to drive the on or off of one or more IGBTs.

In another embodiment, the IGBT of the driving device of the present invention is connected in parallel, and the adapter plate controls the IGBTs to be turned on or off simultaneously.

In another embodiment, the driving board of the driving device of the present invention outputs multiple driving signals to be respectively loaded on the plurality of adapter boards, so as to drive the plurality of parallel IGBTs to be turned on or turned off simultaneously.

The utility model discloses a IGBT drive arrangement controls switching on and turn-off of the IGBT of contravariant bridge through drive plate and adapter plate, and then changes the direct current of rectifier system output into the alternating current so that supply power to the motor. In order to provide the power to the motor of higher power, the utility model discloses a drive arrangement shunts the drive signal of telecommunication of drive plate output through the adapter plate, is used for controlling switching on and shutting off of a plurality of parallelly connected IGBT respectively to adopt RC delay control principle to make a plurality of parallelly connected IGBT switch on and shut off simultaneously. The utility model discloses a drive arrangement is small, and is with low costs, can be applied to the motor of various powers.

Drawings

The above-described features of the present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by reading the following detailed description with reference to the accompanying drawings. The drawings in the following description are only some embodiments of the invention, and other drawings can be derived by those skilled in the art without inventive effort, wherein:

fig. 1 is a schematic block diagram illustrating an IGBT driving apparatus according to an embodiment of the present invention;

fig. 2 is an application schematic diagram illustrating a driving apparatus for driving one IGBT according to an embodiment of the present invention;

fig. 3 is a schematic diagram illustrating driving of one IGBT according to an embodiment of the present invention;

fig. 4 is an application schematic diagram illustrating a driving apparatus for driving two parallel IGBTs according to an embodiment of the present invention; and

fig. 5 is a schematic diagram illustrating driving two parallel IGBTs according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by the skilled in the art without creative work belong to the protection scope of the present invention.

Fig. 1 is a schematic block diagram illustrating an IGBT driving apparatus 100 according to an embodiment of the present invention. It should be noted here that, in order to illustrate an application scenario of the driving device of the present invention, a frequency conversion system and an IGBT are also depicted in fig. 1. The variable frequency system may include a pulse width modulation ("PWM") wave generator, such as may be implemented by a PWM wave generator comprised of a DSP, configured to generate PWM waves to control the turn-on or turn-off of the IGBTs. Specifically, the high-frequency pulse width modulation is used to narrow the voltage width near both ends of the sine wave and widen the voltage width at the center of the sine wave, and to cause the IGBT to operate in one direction at a constant frequency in a half cycle, thereby forming one pulse wave. The pulse wave is then passed through a filter to remove noise and interference, and a sine wave alternating current is formed and supplied to the motor.

As shown in fig. 1, the driving device 100 for inverter IGBT of the present invention comprises a driving board 101 and an adapter board 102, wherein the driving board is configured to receive the PWM electrical signal output by the inverter system, and process the electrical signal through a photocoupler for electrical isolation. And finally, the processed electric signal is amplified by an amplifying circuit and then is used for controlling the on or off of the IGBT.

In one embodiment, the optocoupler may be composed of three parts: a light emitting portion, a light receiving portion, and a signal amplifying portion. Wherein the light emitting part is mainly constituted by the light emitting device. For example, the light emitting diode can convert the received PWM electric signal output by the frequency conversion system into light energy to emit light. The light receiving portion may be formed of a photosensor that converts received light signals from the light emitting diodes into electrical signals. The optical signal amplification section is mainly constituted by an electronic circuit and the like.

When the photoelectric coupler works, the PWM electric signal output by the frequency conversion system is loaded to the input end, so that the core body of the light-emitting device emits light. The photosensitive device generates current after being illuminated and outputs the current after being amplified by the electronic circuit, and the conversion of electricity → light → electricity is realized, so that the electrical isolation of the input end circuit and the output end circuit is realized. The circuits at the input end and the output end of the photoelectric coupler are mutually isolated, and the electric signal has the characteristics of unidirectionality and the like during transmission, so that the photoelectric coupler has good electromagnetic wave interference resistance and electrical insulation capability. Thereby make the utility model discloses a high frequency noise that frequency conversion system probably produced can not disturb IGBT in the work.

In another embodiment, the IGBT may include one or more IGBTs, and when there are a plurality of IGBTs, the plurality of IGBTs are connected in parallel. The adapter board may include a circuit of resistors, capacitors, and diodes configured to control the plurality of IGBTs to be turned on or off simultaneously. In order to better understand the connection manner of the plurality of IGBTs, the IGBTs will be briefly described below.

The IGBT is a composite full-control voltage-driven power semiconductor device consisting of BJTs (bipolar transistors) and MOSFETs (insulated gate field effect transistors), and has the advantages of high input impedance, low on-state voltage and the like. The utility model discloses a IGBT can be the IGBT module, and it can be by IGBT and FWD (freewheel diode chip) through the modularization semiconductor product that specific circuit bridging encapsulation formed, and the IGBT module after the encapsulation can directly be applied to on equipment such as converter and UPS uninterrupted power source.

Further, the IGBT includes three electrodes of C (collector), E (emitter), and G (gate). The switching function is that a channel is formed by loading forward grid voltage, base current is provided for a transistor, and the IGBT is conducted; and conversely, the reverse grid voltage is loaded to eliminate the channel, the base current is cut off, and the IGBT is turned off. When a plurality of IGBTs are connected in parallel, C, E and G three electrodes of the plurality of IGBTs are connected together, respectively, and the respective resistance elements are connected in an auxiliary manner. In addition, the IGBT driving method is substantially the same as the MOSFET, and has a characteristic of high input impedance since only the input-electrode N-channel MOSFET needs to be controlled.

In order to facilitate the technical personnel in the field to better understand the function and structure of the present invention, the following description will be made for the case that the IGBT includes one or more than one IGBT, respectively, with reference to fig. 2 to 5.

Fig. 2 is an application schematic diagram illustrating a driving board driving one IGBT according to an embodiment of the present invention. To illustrate the application scenario of the drive plate, a frequency conversion system, a rectification system and a motor are also depicted in fig. 2. The functions and principles of the frequency conversion system are described in the foregoing frequency conversion system shown in fig. 1, and are not described herein again. The rectification system is configured to convert externally input alternating current into direct current, for example, 380V alternating current can be converted into 540V direct current to be output to the inverter bridge.

As shown in fig. 2, the inverter system includes three inverter bridges, each of which includes an upper bridge and a lower bridge, and each of the upper bridge and the lower bridge includes an IGBT. The E pole of the upper bridge IGBT is connected with the C pole of the lower bridge IGBT, and direct current output by the rectifying system is respectively pressurized to the C pole of the upper bridge IGBT and the E pole of the lower bridge IGBT. The inverter bridge is configured to convert direct current input by the rectifier system into alternating current. Specifically, the IGBT is operated in one direction at a certain frequency in a half cycle, thereby forming a pulse wave. The pulse wave is then passed through a filter to filter out noise and interference, thereby forming a sine wave alternating current to provide power to the motor. Wherein the three-phase alternating current of the motor, as-U, -V and-W in figure 2, is taken between the upper and lower bridges of the three inverter bridges, respectively.

When only one IGBT is driven, the driving device includes a driving board. The drive board is configured to receive a PWM electrical signal output by the frequency conversion system, and output the electrical signal to the adapter board after processing. In one embodiment, the drive board includes a photo coupler and an amplifying circuit. Wherein the photoelectric coupler is configured to photoelectrically convert an electrical signal output from the variable frequency system to electrically isolate the variable frequency system from a driving device. The amplifying circuit is configured to amplify the electrical signal output by the photoelectric coupler so as to output the electrical signal to the adapter board.

Fig. 3 is a schematic diagram illustrating driving of one IGBT according to an embodiment of the present invention. As shown in fig. 3, a driving board directly drives an IGBT, wherein the frequency conversion system may include a PWM wave generator, which may be implemented by a DSP, for example. The PWM electric signal output from the UT1 port of the frequency conversion system is converted into an optical signal through the drive board, then the optical signal is converted into an electric signal, and the electric signal is amplified and output to the UR1 port of the IGBT, so that the IGBT is controlled to be switched on or switched off. When the IGBT is switched on or switched off, firstly, the state information of the IGBT is sent to the drive board through a UT1 port of the IGBT module, then the drive board forwards the information to a UR1 port of the frequency conversion system, and then the information is sent to the upper computer for relevant judgment and processing, and then the upper computer further controls relevant actions of the frequency conversion system according to the processing result of the upper computer, so that a closed-loop working state is formed.

Fig. 4 is an application diagram illustrating a driving apparatus 400 for driving two parallel IGBTs according to an embodiment of the present invention. In comparison with fig. 2, the upper and lower bridges of the inverter bridge in fig. 4 may be respectively composed of two parallel IGBTs, and the turn-on and turn-off of the two parallel IGBTs may be driven by the adaptation board 402.

As shown in fig. 4, the driving device 400 of the present invention includes a driving board 401 and an adapting board 402, and the portion connected to the driving device 400 may include a rectifier system, a frequency conversion system, a motor, etc., wherein the function and principle of the frequency conversion system are referred to the frequency conversion system described in the foregoing fig. 1, and the function and principle of the driving board are referred to the driving board described in the foregoing fig. 2, which are not described again here. The adapter board may include a circuit composed of a resistor, a capacitor, a diode, and the like, and is configured to receive and process the electrical signal processed by the driving board so as to drive one or more IGBTs to turn on or off. Further, when there are a plurality of IGBTs, the IGBTs are connected in parallel, and the adaptation board 402 is configured to control the plurality of IGBTs to be turned on or off simultaneously.

Further, the selection of one or more of the IGBTs is mainly determined by the following reasons. When the power of the motor is relatively small, the current intensity through the IGBT is also required to be relatively small, so that one IGBT can be driven by the driving board by using the technical scheme shown in fig. 2. With the change of the application scene of the motor, the power required by the motor to operate becomes larger and larger, and the current intensity passed by one IGBT cannot meet the requirement of a high-power motor. Therefore, the parallel connection of a plurality of IGBTs can be adopted to increase the current passing intensity of the IGBTs after parallel connection. When designing an IGBT parallel system, firstly, determining the appropriate number of IGBT modules connected in parallel to obtain enough rated current, and simultaneously ensuring that each IGBT module does not exceed a safe working area when working.

The parallel connection of the IGBTs to form the switching device can make the whole inverter system obtain higher rated current, but important problems such as module characteristics, driving circuits and circuit layout must be considered when designing the parallel connection system, and these factors affect the current distribution of the parallel branch circuits, which may cause the current distribution of each parallel IGBT to be unbalanced. Due to the imbalance in current distribution, the rated current for connecting two IGBTs in parallel is not equal to twice the rated current of a single module, so parallel IGBT modules must be derated. The current-voltage characteristics in the module characteristics mainly affect current distribution during static operation, and the transfer characteristics, the driving circuit and the layout mainly affect current distribution during dynamic operation.

As shown in fig. 4, when two IGBTs are connected in parallel, G, C and E poles thereof are connected together, respectively. The IGBT can be placed on the adapter board so that the distance between the IGBT and the adapter board is as small as possible. When the driving device works, the driving plate receives PWM electric signals (such as UT1, VT1 and WT1 in the figure) output by the frequency conversion system, then the PWM electric signals are subjected to electric → optical → electric conversion through a photoelectric coupler and are output to the adapter plate after signal amplification, and the adapter plate loads the processed electric signals onto the two IGBTs so that the two parallel IGBTs are simultaneously switched on or off. And finally, the total output current intensity of the IGBTs after parallel connection is increased, so that a motor with higher power can be supplied, wherein three phases of electricity-U, -V and-W of the motor are respectively taken from the upper bridge and the lower bridge of the three inverter bridges.

Fig. 5 is a schematic diagram illustrating driving two parallel IGBTs according to an embodiment of the present invention. At this time, if the scheme shown in fig. 3 is also adopted to drive two IGBTs simultaneously by using one driving board, the electrical signal output by the driving board output port UT1 must be divided into two, and the two IGBTs cannot be connected in parallel. Therefore, in order to realize the parallel connection of the two IGBTs and control the two IGBTs to be turned on and off simultaneously, the technical scheme using the adapter board shown in fig. 5 may be adopted.

In one embodiment, the driving board of the driving apparatus of the present invention outputs multiple driving signals to be respectively loaded on the plurality of adapter boards, so as to drive the plurality of parallel IGBTs to be turned on or turned off simultaneously. Specifically, in order to ensure that each parallel IGBT obtains a +15V conduction voltage at the same time, an adapter plate is additionally arranged on each two parallel IGBTs to ensure that the IGBTs are simultaneously turned on and off. In one embodiment, alternating current with the frequency of 50HZ is generated by turning on and off the IGBTs, wherein one sine wave cycle is completed in 0.02 second, so that the time for two parallel IGBTs to act successively must be controlled within a few nanoseconds, otherwise the IGBTs can be damaged, and even the situation of IGBT explosion can occur.

It should be understood that the terms "first," "second," "third," and "fourth," etc. in the claims, description, and drawings of the present invention are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this disclosure, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the invention. As used in the specification and claims of this application, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the specification and claims of the present invention refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.

Although the present invention has been described with reference to the above embodiments, the description is only for the convenience of understanding the present invention, and is not intended to limit the scope or application of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

1. A drive arrangement (100) for a frequency converter IGBT, comprising a drive plate (101) configured to receive an electrical signal output by a frequency conversion system and to process said electrical signal for output after isolation and amplification,

the driving device (100) further comprises one or more adapter boards (102), wherein the adapter boards (102) are configured to receive and process the electric signals processed by the driving board (101) so as to drive the IGBTs to be switched on or off.

2. The drive device (100) of claim 1, wherein the drive plate (101) comprises an opto-coupler configured to photoelectrically convert an electrical signal output by the variable frequency system to electrically isolate the variable frequency system from the drive device (100).

3. The driving device (100) according to claim 2, wherein the driving board (101) further comprises an amplifying circuit configured to amplify the electrical signal output by the photocoupler so as to be output to the adapting board (102).

4. The driving device (100) according to claim 1, wherein the adapter board (102) comprises a circuit of a resistor, a capacitor and a diode for driving the IGBT to turn on or off.

5. The driving device (100) according to claim 4, wherein the IGBTs are connected in parallel, and the adapter board (102) is configured to drive the IGBTs to be turned on or off simultaneously.

6. The driving device (100) according to claim 5, wherein the driving board (101) outputs multiple driving signals to be respectively loaded on the plurality of the adaptation boards (102) so as to drive the plurality of parallel IGBTs to be simultaneously turned on or off.

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