CN210807126U - Driving circuit capable of switching driving modes, frequency converter and equipment - Google Patents

Abstract

The utility model discloses a drive circuit, converter and equipment of changeable drive mode. Wherein, this circuit includes: the rectifying unit comprises a first input end and an output end, the output end of the rectifying unit is connected with the input end of the inverting unit, and a line between the rectifying unit and the inverting unit is connected with a second input end of the rectifying unit; the first switch is arranged between the first input end of the rectifying unit and the output end of the inverting unit and is used for controlling the driving circuit to switch between a series mode and a parallel mode by opening or closing; the output end of the inversion unit is connected with a load; electric capacity, parallel access the rectifier unit with between the contravariant unit, through the utility model discloses, realize drive circuit's the series connection and the switching of parallelly connected mode to the messenger is changed into reserve contravariant unit by idle rectifier unit, obtains make full use of.

Description

Driving circuit capable of switching driving modes, frequency converter and equipment

Technical Field

The utility model relates to an electron electric power technical field particularly, relates to a drive circuit, converter and equipment of changeable drive mode.

Background

With the development of power electronic technology and the rapid development of current conversion technology, more and more direct current power supply systems are available, as shown in fig. 1, a common direct current power supply frequency converter is transformed from an existing alternating current input frequency converter, the alternating current frequency converter is divided into a rectifying unit and an inverting unit, the rectifying unit is responsible for converting alternating current voltage into direct current voltage, direct current can be input from the front end of the rectifying unit, the direct current is conducted by using a diode inside a module, and meanwhile, the work of preventing reverse connection is performed to realize a direct current driving motor.

Aiming at the problem that a rectifying unit is idle when an alternating current input frequency converter is changed into a direct current input frequency converter in the prior art, an effective solution is not provided at present.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an in provide a drive circuit, converter and equipment of changeable drive mode to when alternating current input converter changes the direct current input converter among the solution prior art, the rectification unit is by idle problem.

In order to solve the above technical problem, the utility model provides a drive circuit of changeable drive mode, wherein, this circuit includes:

the rectifying unit comprises a first input end and an output end, the output end of the rectifying unit is connected with the input end of the inverting unit, and a line between the rectifying unit and the inverting unit is connected with a second input end of the rectifying unit;

the first switch is arranged between the first input end of the rectifying unit and the output end of the inverting unit and is used for controlling the driving circuit to switch between a series mode and a parallel mode by opening or closing;

the output end of the inversion unit is connected with a load;

and the capacitor is connected between the rectifying unit and the inverting unit in parallel.

Further, the circuit further comprises: and one end of the second switch is connected with the direct-current power supply, and the other end of the second switch is alternatively connected with the first input end or the second input end of the rectifying unit.

Further, the second switch is a double-pole double-throw switch.

Further, the rectifying unit includes a three-phase rectifier bridge circuit.

Further, the inverter unit includes a three-phase inverter bridge circuit.

The utility model also provides a converter, including above-mentioned drive circuit.

The utility model also provides an equipment, including the motor, still include above-mentioned converter.

Use the technical scheme of the utility model, draw forth the second input of rectification unit between current rectification unit output and contravariant unit input to set up first switch between the input of rectification unit and contravariant unit, through switching on of control second input or second input, realize drive circuit's the series connection and the switching of parallelly connected mode, thereby make and be changed into reserve contravariant unit by idle rectification unit, obtain make full use of.

Drawings

Fig. 1 is a structural diagram of a frequency converter in the prior art;

fig. 2 is a block diagram of a drive circuit according to an embodiment of the present invention;

fig. 3 is a block diagram of a driving circuit according to another embodiment of the present invention;

fig. 4 is a block diagram of a series mode drive circuit according to an embodiment of the present invention;

fig. 5 is a block diagram of a parallel mode drive circuit according to an embodiment of the present invention;

fig. 6 is a diagram of a driving circuit structure according to still another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the embodiments of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and "a plurality" typically includes at least two.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that although the terms first, second, etc. may be used to describe the switches in the embodiments of the present invention, the switches should not be limited to these terms. These terms are only used to distinguish between differently acting switches. For example, a first switch may also be referred to as a second switch, and similarly, a second switch may also be referred to as a first switch, without departing from the scope of embodiments of the present invention.

The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to a detection", depending on the context. Similarly, the phrases "if determined" or "if detected (a stated condition or event)" may be interpreted as "when determined" or "in response to a determination" or "when detected (a stated condition or event)" or "in response to a detection (a stated condition or event)", depending on the context.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in the article or device in which the element is included.

The following describes in detail alternative embodiments of the present invention with reference to the accompanying drawings.

Example 1

This embodiment provides a drive circuit of changeable drive mode, and fig. 2 is the structure diagram of the drive circuit according to the embodiment of the present invention, as shown in fig. 2, this drive circuit includes: the rectifying unit 11 comprises a first input end and an output end, the first input end comprises a first connection end a1, a second connection end a2 and a third connection end a3, the output end of the rectifying unit 11 is connected with the input end of the inverting unit 12, a line between the rectifying unit 11 and the inverting unit 12 is connected with the second input end of the rectifying unit 11, and the second input end comprises a third connection end b1 and a fourth connection end b 2; a first switch K1, disposed between the first input terminal of the rectifying unit 11 and the output terminal of the inverting unit 12, for controlling the driving circuit to switch between the series mode and the parallel mode by opening or closing; the output end of the inversion unit 12 is connected with a load; and the capacitor C is connected between the rectifying unit and the inverting unit in parallel and is charged through the rectifying unit 11.

In a series mode, when in a specific implementation, the first switch K1 is turned off, the first connection end a1 and the second connection end a2 of the first input end of the rectification unit 11 are connected to a dc power supply, the rectification unit 11 and the inversion unit 12 are connected in series between the dc power supply and a load 13, the dc power passes through the rectification unit 11 and then the inversion unit 12, and is converted into an ac power, which is output to the load 13; in a parallel mode, the first switch K1 is closed, the third connection terminal b1 and the fourth connection terminal b2 of the second input end of the rectifying unit 11 are conducted with a direct current power supply, the rectifying unit 11 and the inverting unit 12 are connected in parallel between the direct current power supply and the load 13, and one path of direct current passes through the inverting unit 12 to convert the direct current into alternating current and output the alternating current to the load 13; the other direct current passes through the second input end of the rectifying unit 11, and then passes through the first connection end point a1, the second connection end point a2 and the third connection end point a3 of the first input end of the rectifying unit 11, and then is output to the load 13, because the second input end of the rectifying unit 11 is connected with the output end of the original rectifying unit 11, and the first input end is connected with the load 13 through the first switch K1, when the driving circuit is switched from the series mode to the parallel mode, the original output end of the rectifying unit 11 becomes the direct current input end, the original first input end becomes the direct current output end, the initial function of the rectifying unit 11 is to convert the alternating current into the direct current, after the input end and the output end are exchanged, the function is to convert the direct current into the alternating current, the function is the same as that of the inverting unit 12, therefore, the rectifying unit can be used as a backup inverting unit, when the inverting unit 12 in, when the rectifier unit is out of normal use, the output end of the rectifier unit 11 can be conducted with the first input end, the first input end of the rectifier unit 11 is controlled to be conducted with the load 13, and the effect of converting direct current into alternating current is achieved through the rectifier unit 11 to drive the load.

The second input end of the rectifying unit is led out between the output end of the existing rectifying unit and the input end of the inversion unit, the first switch is arranged between the input end of the rectifying unit and the inversion unit, switching between a series mode and a parallel mode of the driving circuit is achieved by controlling conduction of the second input end or the second input end, and therefore the idle rectifying unit is converted into the standby inversion unit to be fully utilized.

Example 2

This embodiment provides another driving circuit capable of switching driving modes, fig. 3 is a structural diagram of a driving circuit according to another embodiment of the present invention, in order to implement switching between series mode and parallel mode using the same dc power supply, as shown in fig. 3, on the basis of the above implementation, the driving circuit further includes: the second switch K2, one end of the second switch K2 is connected to a direct current power supply, and the other end of the second switch K2 is alternatively connected to the first input end or the second input end of the rectifying unit 11, when the serial mode needs to be switched, one end of the second switch K2 is controlled to be conducted to the direct current power supply, the other end of the second switch K2 is controlled to be conducted to the first input end of the rectifying unit 11, so that the direct current power sequentially passes through the rectifying unit 11 and the inverting unit 12, and then is output to the load 13, when the parallel mode needs to be switched, one end of the second switch K2 is conducted to the direct current power supply, and the other end of the second switch K2 is conducted to the second input end of the rectifying unit 11, so that the direct.

In a specific implementation, in order to realize simultaneous switching of two connection points, the second switch K2 is a double-pole double-throw switch, and when it is required to switch to the series mode, one end of the second switch K2 is controlled to be conducted with the dc power supply, one of the gates of the other ground is controlled to be thrown at the first connection end a1 of the first input end of the rectifying unit 11, the other gate is controlled to be thrown at the second connection end a2 of the first input end of the rectifying unit 11, when it is required to switch to the parallel mode, one end of the second switch K2 is controlled to be conducted with the dc power supply, one of the gates of the other ground is controlled to be thrown at the third connection end b1 of the second input end of the rectifying unit 11, and the other gate is controlled to be thrown at the fourth connection end b2 of the second input end of the rectifying unit 11.

It should be noted that, the above is only one preferred embodiment of the present invention, in other embodiments, the second switch K2 may also include a first sub switch, a second sub switch, a third sub switch and a fourth sub switch, which are respectively disposed at the first connection endpoint a1, the second connection endpoint a2, the third connection endpoint b1, the fourth connection endpoint b2 and the dc power supply time, and control the first sub switch and the second sub switch to be turned on in the series mode, and control the third sub switch and the fourth sub switch to be turned on in the parallel mode.

Fig. 4 is a block diagram of a series mode driving circuit according to an embodiment of the present invention, and as shown in fig. 4, the rectifying unit 11 includes a three-phase rectifying bridge circuit including a first bridge rectifying bridge including a first transistor Q1 having an internal antiparallel diode and a second transistor Q2 having the same structure, a second rectifying bridge including a first connection terminal a1 and a third transistor Q1 having a line connection between a first transistor Q1 and a second transistor Q2, and a third rectifying bridge including a third transistor Q3 and a fourth transistor Q4 having the same structure as the first transistor Q1, a line connection between the third transistor Q3 and the fourth transistor Q4 is connected to the second connection terminal a2, a third bridge rectifying bridge including a fifth transistor Q36 and a sixth transistor Q6 having the same structure as the first transistor Q1, a line connection between the fifth transistor Q5 and the sixth transistor Q6 is connected to the third transistor Q9638, in the series mode, the first connection terminal a1 and the second connection terminal a2 are connected to the positive and negative poles of the dc power source, and the third connection terminal a3 is floating.

As shown in fig. 4, the inverter unit includes a three-phase inverter bridge circuit including a first bridge inverter bridge including a seventh transistor Q7 having an internal inverse parallel diode and an eighth transistor Q8 having the same structure, a line between the seventh transistor Q7 and the eighth transistor Q8 being connected to the first phase line U, a second inverter bridge including ninth and tenth transistors Q9 and Q10 having the same structure as the seventh transistor Q7, a line between the ninth and tenth transistors Q9 and Q10 being connected to the second phase line V, and a third inverter bridge including eleventh and twelfth transistors Q11 and Q12 having the same structure as the seventh transistor Q7, a line between the eleventh and twelfth transistors Q11 and Q12 being connected to the third phase line W, in a series mode, the first phase line U, the second phase line V and the third phase line W output three-phase alternating current to a load.

Fig. 5 is a structure diagram of a parallel mode's drive circuit according to the embodiment of the present invention, as shown in fig. 5, in parallel mode, dc power is connected to the input of the rectifying unit 11, and after dc power passes through the three-phase rectifier bridge, three-phase ac power is output to the load through the first phase line U, the second phase line V and the third phase line W, and the first phase line U, the second phase line V and the third phase line W of the rectifying unit 11 are three lines connected to the first connection endpoint a1 and the second connection endpoint a2 of the first input of the rectifying unit 11 and the third connection endpoint a3 respectively in series mode.

Example 3

This embodiment provides another driving circuit capable of switching driving modes, fig. 6 is a structural diagram of a driving circuit according to another embodiment of the present invention, as shown in fig. 6, the driving circuit includes:

a rectifier module 51 (i.e., the rectifier unit 11 in the above embodiment), an inverter module 52 (i.e., the inverter unit 12 in the above embodiment), a motor load 53 (i.e., the load 13 in the above embodiment), a mode-switching switch K3 (i.e., the first switch K1 in the above embodiment), a selection switch K4 (i.e., the second switch K2 in the above embodiment), and a capacitor C1, wherein the rectifier module 51 includes a first input end and an output end, the output end of the rectifier module 51 is connected to the input end of the inverter module 52, and a line between the rectifier module 51 and the inverter module 52 is connected to the second input end of the rectifier module 51; the output end of the inversion module 52 is connected with a load; the mode switching switch K3 is disposed between the first input end of the rectifying module 51 and the output end of the inverting module 52, and is configured to control the driving circuit to switch between a series mode and a parallel mode by being opened or closed; the selection switch K4 is used for alternatively enabling the dc power supply to be conducted with the first dc input end or the second dc input end of the rectifier module 51; the capacitor C1 is connected in parallel between the rectifying unit and the inverting unit, and the capacitor C1 is charged through the rectifying module 51.

In the embodiment, idle rectification modules after the direct current input of the universal frequency converter can be utilized to form a standby inverter module or a power voltage module which is changed into parallel connection to drive the motor load 53, redundant backup or power sharing between modules is realized to drive the motor load 53, and a driving circuit which supports parallel operation or is provided with a redundant inverter unit is formed. The working principle of the embodiment is as follows:

firstly, charging an intermediate capacitor by using the original structure of a frequency converter, wherein the structure conversion must be carried out after the intermediate capacitor is charged; the method specifically comprises the following steps: the selection switch K4 is controlled to be thrown at the first direct current input end, the capacitor C1 is charged through the direct current module 51, and after the charging is completed, voltage is generated at two ends of the capacitor C1;

then, after the capacitor C1 generates a voltage, the selection switch K4 is switched from the first dc input terminal to the second dc input terminal, and the mode switching switch K3 is closed, switching the driving circuit to the parallel mode.

After the mode switching is finished, the output end (i.e. the first input end in the above embodiment) of the rectifier module 51 is already connected to the motor load 53; the rectification module 51 and the inversion module form a parallel driving system or a redundant backup driving system;

the utility model is suitable for the frequency conversion centrifuge and the air conditioner with AC input and all occasions needing to convert the DC input into the AC input through the frequency converter; the effect of the rectifier modules running in parallel is the same as that of the inverter modules, part of power of the inverter modules can be equally divided, the redundant inverter modules are used for supplying power to the motor load, namely, after one of the inverter modules breaks down, the other inverter module can be used as a standby inverter module to supply power to the motor load immediately, and standby of the redundant inverter modules is achieved.

Example 4

The embodiment provides a frequency converter, which comprises the driving circuit.

Example 5

This embodiment also provides an apparatus, which includes a motor and the frequency converter of embodiment 5.

The above-described circuit embodiments are only illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims (7)

1. A driver circuit, the circuit comprising:

the rectifying unit comprises a first input end and an output end, the output end of the rectifying unit is connected with the input end of the inverting unit, and a line between the rectifying unit and the inverting unit is connected with a second input end of the rectifying unit;

the first switch is arranged between the first input end of the rectifying unit and the output end of the inverting unit and is used for controlling the driving circuit to switch between a series mode and a parallel mode by opening or closing;

the output end of the inversion unit is connected with a load;

and the capacitor is connected between the rectifying unit and the inverting unit in parallel.

2. The circuit of claim 1, further comprising: and one end of the second switch is connected with the direct-current power supply, and the other end of the second switch is alternatively connected with the first input end or the second input end of the rectifying unit.

3. The circuit of claim 2, wherein the second switch is a double pole double throw switch.

4. The circuit of claim 1, wherein the rectification unit comprises a three-phase rectifier bridge circuit.

5. The circuit of claim 1, wherein the inverting unit comprises a three-phase inverter bridge circuit.

6. A frequency converter, characterized by comprising a drive circuit according to any one of claims 1 to 5.

7. An apparatus comprising an electric machine, characterized in that the apparatus further comprises a frequency converter according to claim 6.

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