CN215817938U - Frequency converter - Google Patents
Frequency converter Download PDFInfo
- Publication number
- CN215817938U CN215817938U CN202121226484.3U CN202121226484U CN215817938U CN 215817938 U CN215817938 U CN 215817938U CN 202121226484 U CN202121226484 U CN 202121226484U CN 215817938 U CN215817938 U CN 215817938U
- Authority
- CN
- China
- Prior art keywords
- circuit
- rectifying
- inverter circuit
- igbt tube
- control unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Inverter Devices (AREA)
Abstract
The embodiment of the utility model relates to the technical field of electronic power, in particular to a frequency converter. The embodiment of the utility model provides a frequency converter, which comprises a box body, a rectifying circuit, an energy storage circuit, a switch unit, a brake unit, an inverter circuit and a control unit, wherein the box body is provided with a first end and a second end; the box body is provided with an accommodating space, the rectifying circuit, the energy storage circuit, the switch unit, the inverter circuit and the control unit are accommodated in the accommodating space, and the brake unit is arranged outside the box body; through at the inside integrated switch unit of converter, closed switch when the tank circuit voltage is too high, the brake unit begins work to realize the braking, in addition, because switch unit integration is inside the converter, can reduce the volume of whole equipment, and the cost is lower.
Description
Technical Field
The embodiment of the utility model relates to the technical field of electronic power, in particular to a frequency converter.
Background
The frequency converter is the power control equipment for controlling the alternating current motor by changing the frequency of the working power supply of the motor, along with the improvement of the industrial automation degree, the frequency converter is widely applied to various fields as speed-adjustable driving equipment, and the application occasions of a plurality of frequency converter driving motors need to have a braking function, namely, the capability of quickly stopping and quickly reducing the speed.
In the current frequency converter, an external braking unit and an external switching unit are generally required to be additionally configured to provide braking for the interior of the frequency converter, however, the external high-power switching unit and the external braking unit are additionally configured, so that the volume of the whole equipment is increased, and the cost is high.
SUMMERY OF THE UTILITY MODEL
The embodiment of the utility model provides a frequency converter, which can reduce the volume of the whole equipment and has lower cost by integrating a switch unit in the frequency converter.
The embodiment of the utility model adopts a technical scheme that: provided is a frequency converter including: the brake device comprises a box body, a rectifying circuit, an energy storage circuit, a switch unit, a brake unit, an inverter circuit and a control unit;
the box body is provided with an accommodating space, the rectifying circuit, the energy storage circuit, the switch unit, the inverter circuit and the control unit are accommodated in the accommodating space, and the brake unit is arranged outside the box body;
the rectification circuit, the energy storage circuit and the inverter circuit are connected in sequence;
the switch unit is connected with the brake unit to form a brake circuit, the brake circuit is connected in series between the energy storage circuit and the inverter circuit, the switch unit is further connected with a first end of the control unit, the control unit is used for outputting a first control signal to the switch unit when the voltage of the energy storage circuit is too high, and the switch unit is used for controlling the brake unit to work according to the first control signal.
In some embodiments, the frequency converter further comprises a snubber circuit, a positive dc bus, and a negative dc bus;
the buffer circuit, the positive direct current bus and the negative direct current bus are contained in the containing space;
the first end of the rectifying circuit is connected with the first end of the inverter circuit through the positive direct current bus, and the second end of the rectifying circuit is connected with the second end of the inverter circuit through the negative direct current bus;
the third end of the rectifying circuit is used for connecting an external power supply, and the rectifying circuit is used for converting the first alternating current of the external power supply into a first direct current;
the third end of the inverter circuit is used for connecting an external device, and the inverter circuit is used for converting the first direct current into a second alternating current and outputting the second alternating current to the external device;
the energy storage circuit is connected in series between the positive direct current bus and the negative direct current bus, is arranged between the rectifying circuit and the inverter circuit, and is used for storing the first direct current;
the buffer circuit is connected in series between the rectifying circuit and the positive direct-current bus, or the buffer circuit is connected in series between the rectifying circuit and the negative direct-current bus, and the buffer circuit is used for electrically buffering the frequency converter.
In some embodiments, the switching unit is a first IGBT, a collector of the first IGBT is connected to the positive dc bus, an emitter of the first IGBT is connected to the first end of the braking unit, a gate of the first IGBT is connected to the first end of the control unit, and a second end of the braking unit is connected to the negative dc bus.
In some embodiments, the braking unit is a braking resistor.
In some embodiments, the voltage range of the first alternating current is 520V-690V, and the output power of the frequency converter is 37 KW.
In some embodiments, the frequency converter further comprises a voltage detection unit;
the first end of the voltage detection unit is connected with the energy storage circuit, the second end of the voltage detection unit is connected with the second end of the control unit, the voltage detection unit is used for detecting the voltage of the energy storage circuit and outputting the voltage to the control unit, and the control unit is used for outputting the first control signal according to the voltage.
In some embodiments, the rectifier circuit has a first input, a second input, a third input, a first output, and a second output, the rectifier circuit includes a first rectifier diode, a second rectifier diode, a third rectifier diode, a fourth rectifier diode, a fifth rectifier diode, and a sixth rectifier diode;
the anode of the first rectifying diode is connected with the first input end of the rectifying circuit, the cathode of the first rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the fourth rectifying diode is connected with the first input end of the rectifying circuit, and the anode of the fourth rectifying diode is connected with the second output end of the rectifying circuit;
the anode of the second rectifying diode is connected with the second input end of the rectifying circuit, the cathode of the second rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the fifth rectifying diode is connected with the second input end of the rectifying circuit, and the anode of the fifth rectifying diode is connected with the second output end of the rectifying circuit;
the anode of the third rectifying diode is connected with the third input end of the rectifying circuit, the cathode of the third rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the sixth rectifying diode is connected with the third input end of the rectifying circuit, and the anode of the sixth rectifying diode is connected with the second output end of the rectifying circuit;
the first input end of the rectifying circuit, the second input end of the rectifying circuit and the third input end of the rectifying circuit are all used for being connected with the external power supply;
the buffer circuit is connected in series between the first output end of the rectifying circuit and the positive direct-current bus, the second output end of the rectifying circuit is connected with the negative direct-current bus, or the buffer circuit is connected in series between the second output end of the rectifying circuit and the negative rectifying bus, and the first output end of the rectifying circuit is connected with the positive direct-current bus.
In some embodiments, the snubber circuit includes a snubber resistor and a contactor connected in parallel;
the contactor is further connected with a third end of the control unit, the control unit is further used for outputting a second control signal, and the contactor is used for controlling the buffer resistor to work according to the second control signal.
In some embodiments, the energy storage circuit comprises at least one electrolytic capacitor bank connected in series, and the electrolytic capacitor bank is formed by connecting an electrolytic capacitor and a voltage dividing resistor in parallel.
In some embodiments, the inverter circuit has a first input terminal, a second input terminal, a first output terminal, a second output terminal and a third output terminal, and the inverter circuit includes a second IGBT transistor, a third IGBT transistor, a fourth IGBT transistor, a fifth IGBT transistor, a sixth IGBT transistor and a seventh IGBT transistor;
a collector of the second IGBT tube is connected with a first input end of the inverter circuit, an emitter of the second IGBT tube is connected with a first output end of the inverter circuit, a collector of the fifth IGBT tube is connected with a first output end of the inverter circuit, and an emitter of the fifth IGBT tube is connected with a second input end of the inverter circuit;
a collector of the third IGBT tube is connected with a first input end of the inverter circuit, an emitter of the third IGBT tube is connected with a second output end of the inverter circuit, a collector of the sixth IGBT tube is connected with a second output end of the inverter circuit, and an emitter of the sixth IGBT tube is connected with a second input end of the inverter circuit;
a collector electrode of the fourth IGBT tube is connected with the first input end of the inverter circuit, an emitter electrode of the fourth IGBT tube is connected with the third output end of the inverter circuit, a collector electrode of the seventh IGBT tube is connected with the third output end of the inverter circuit, and an emitter electrode of the seventh IGBT tube is connected with the second input end of the inverter circuit;
a first input end of the inverter circuit is connected with the positive direct-current bus, and a second input end of the inverter circuit is connected with the negative direct-current bus;
the first output end of the inverter circuit, the second output end of the inverter circuit and the third output end of the inverter circuit are all used for being connected with the external equipment;
the gate pole of the second IGBT tube is connected with the fourth end of the control unit, the fifth end of the third IGBT tube is connected with the fifth end of the control unit, the sixth end of the fourth IGBT tube is connected with the sixth end of the control unit, the seventh end of the fifth IGBT tube is connected with the seventh end of the control unit, the eighth end of the sixth IGBT tube is connected with the eighth end of the control unit, and the seventh IGBT tube is connected with the ninth end of the control unit.
The beneficial effects of the embodiment of the utility model are as follows: different from the situation of the prior art, the embodiment of the utility model provides a frequency converter, which comprises a box body, a rectifying circuit, an energy storage circuit, a switch unit, a brake unit, an inverter circuit and a control unit; the box body is provided with an accommodating space, the rectifying circuit, the energy storage circuit, the switch unit, the inverter circuit and the control unit are accommodated in the accommodating space, and the brake unit is arranged outside the box body; through at the inside integrated switch unit of converter, closed switch when the tank circuit voltage is too high, the brake unit begins to work, thereby realize the braking, in addition, because the switch unit is integrated inside the converter, can form simple control circuit structure through concatenating the switch unit between main circuit and brake unit, with this control to the brake unit of realization, set up in the complicated control circuit that the box outside formed for the switch unit, the control circuit structure is simpler, thereby can reduce the volume of whole equipment, and the cost is lower.
Drawings
One or more embodiments are illustrated by the accompanying figures in the drawings that correspond thereto and are not to be construed as limiting the embodiments, wherein elements/modules and steps having the same reference numerals are represented by like elements/modules and steps, unless otherwise specified, and the drawings are not to scale.
Fig. 1 is a schematic structural block diagram of a frequency converter according to an embodiment of the present invention;
fig. 2 is a schematic structural block diagram of another frequency converter provided in the embodiment of the present invention;
fig. 3 is a schematic structural block diagram of another frequency converter according to an embodiment of the present invention;
fig. 4 is a schematic circuit structure diagram of a frequency converter according to an embodiment of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the utility model, but are not intended to limit the utility model in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the utility model. All falling within the scope of the present invention.
In order to facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific embodiments. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
It should be noted that, if not conflicted, the various features of the embodiments of the utility model may be combined with each other within the scope of protection of the present application. In addition, although the functional blocks are divided in the device diagram, in some cases, the blocks may be divided differently from those in the device. Further, the terms "first," "second," and the like, as used herein, do not limit the data and the execution order, but merely distinguish the same items or similar items having substantially the same functions and actions.
Referring to fig. 1, a frequency converter 100 according to an embodiment of the present invention includes: the device comprises a box body 10, a rectifying circuit 20, an energy storage circuit 30, an inverter circuit 40, a switch unit 51, a brake unit 52 and a control unit 60. The box body 10 is provided with an accommodating space, the rectifying circuit 20, the energy storage circuit 30, the switch unit 51, the inverter circuit 40 and the control unit 60 are all accommodated in the accommodating space, and the brake unit 52 is arranged outside the box body 10. The rectifying circuit 20, the tank circuit 30 and the inverter circuit 40 are connected in sequence. The switch unit 51 and the brake unit 52 are connected to form a brake circuit, the brake circuit is connected in series between the energy storage circuit 30 and the inverter circuit 40, the switch unit 51 is further connected to a first end of the control unit 60, the control unit 60 is used for outputting a first control signal to the switch unit 51 when the voltage of the energy storage circuit 30 is too high, and the switch unit 51 is used for controlling the brake unit 52 to work according to the first control signal.
In the inverter 100, the rectifier circuit 20, the tank circuit 30, and the inverter circuit 40 are connected in this order to realize the function of the inverter 100. The switch unit 51 is further integrated inside the case 10 of the frequency converter 100, the switch unit 51 is used for controlling the brake unit 52 outside the case 10 to operate, when the voltage of the energy storage circuit 30 is too high, the control unit 60 outputs a first control signal to the switch unit 51, the switch unit 51 is closed, the connection with the brake unit 52 is conducted, the brake unit 52 starts to operate, energy consumption is achieved, and braking is achieved. Thus, by integrating the high-power switch unit 51 inside the frequency converter 100, the control of the brake unit 52 can be realized only by arranging the brake unit 52 outside the box 10, and a complex control circuit for controlling the brake unit 52 to work is not required to be configured outside the box, so that the volume of the whole equipment can be reduced, and meanwhile, the whole cost is lower.
Specifically, in some embodiments, referring to fig. 2, the frequency converter 100 further includes a buffer circuit 70, a positive dc bus 81, and a negative dc bus 82. The buffer circuit 70, the positive dc bus 81, and the negative dc bus 82 are all housed in the housing space of the case 10. The brake circuit is connected in series between the positive dc bus 81 and the negative dc bus 82, and the brake circuit is disposed between the energy storage circuit 30 and the inverter circuit 40. A first end of the rectifying circuit 20 is connected with a first end of the inverter circuit 40 through a positive direct current bus 81, and a second end of the rectifying circuit 20 is connected with a second end of the inverter circuit 40 through a negative direct current bus 82; the third end of the rectifying circuit 20 is used for connecting an external power supply, and the rectifying circuit 20 is used for converting the first alternating current of the external power supply into a first direct current; the third terminal of the inverter circuit 40 is used for connecting an external device, and the inverter circuit 40 is used for converting the first direct current into the second alternating current and outputting the second alternating current to the external device.
Thus, the rectifier circuit 20, the positive dc bus 81, the inverter circuit 40, and the negative dc bus 82 are connected to constitute a main circuit of the inverter 100. The energy storage circuit 30 is connected in series between the positive direct current bus 81 and the negative direct current bus 82, the energy storage circuit 30 is arranged between the rectifying circuit 20 and the inverter circuit 40, and the energy storage circuit 30 is used for storing a first direct current; the buffer circuit 70 is connected in series between the rectifying circuit 20 and the positive dc bus 81, or the buffer circuit 70 is connected in series between the rectifying circuit 20 and the negative dc bus 82, and the buffer circuit 70 is used for electrically buffering the frequency converter 100. In the frequency converter 100, the rectifying circuit 20, the energy storage circuit 30 and the inverter circuit 40 are connected through the positive dc bus 81 and the negative dc bus 82 to realize the function of the frequency converter 100, and the voltage and the frequency of the external power supply are changed in an ac-dc-ac manner, so as to provide a required power supply for the external device, specifically, the external device may be a motor or other power equipment and loads requiring a specific large power supply voltage and frequency, and meanwhile, the buffer circuit 70 may slowly charge the energy storage circuit 30 after being powered on, so as to suppress surge current. In addition, as the switch unit is integrated in the frequency converter, a simple control circuit structure can be formed by connecting the switch unit between the direct current bus and the brake unit in series.
In some embodiments, the output power of the frequency converter is 37KW, and in the case of a large power, the current is large, which results in a complicated control circuit of the switching unit, and by integrating the switching unit with high power control inside, the design cost of the whole device can be reduced.
In some embodiments, the voltage range of the first ac power is 520V-690V, and in practical applications, the voltage range of the first ac power may be 442V-759V. The voltage range of the second alternating current is 0V to the voltage value of the first alternating current; the input power of the frequency converter is 37KW, and the input current and the output current are both 47A. In particular, the control unit may employ a microprocessor controller of the STM8, STM16, STM32 family or any other suitable controller for receiving and outputting data.
In some embodiments, referring to fig. 3, the frequency converter 100 further includes a voltage detection unit 90; a first end of the voltage detection unit 90 is connected to the tank circuit 30, a second end of the voltage detection unit 90 is connected to a second end of the control unit 60, the voltage detection unit 90 is configured to detect voltages at two ends of the tank circuit 30 and output the voltages to the control unit 60, and the control unit 60 is configured to output a first control signal according to the voltages.
In some embodiments, referring to fig. 4, the switching unit 51 is a first IGBT Q1, a collector of the first IGBT Q1 is connected to the positive dc bus 81, an emitter of the first IGBT Q1 is connected to the first end of the braking unit 52, a gate of the first IGBT Q1 is connected to the first end of the control unit 60, and a second end of the braking unit 52 is connected to the negative dc bus 82. Specifically, the braking unit 52 is a braking resistor R4, and when it is detected that the voltage across the energy storage circuit 30 is higher than the preset value, the control unit 60 outputs a first control signal with a high level to the first IGBT Q1, and the first IGBT Q1 is turned on, so that the braking resistor R4 is connected in series between the positive dc bus 81 and the negative dc bus 82, and the braking resistor R4 starts to operate to consume excess electric power, thereby reducing the voltage across the energy storage circuit 30, and when it is detected that the voltage across the energy storage circuit 30 is lower than the preset value, the control unit 60 outputs a low level signal to the first IGBT Q1, and the first IGBT Q1 is not turned on, so that the braking resistor R4 does not operate.
In some of the embodiments, the rectifying circuit 20 has a first input terminal T, a second input terminal S, a third input terminal R, a first output terminal and a second output terminal, and the rectifying circuit 20 includes a first rectifying diode D1, a second rectifying diode D2, a third rectifying diode D3, a fourth rectifying diode D4, a fifth rectifying diode D5 and a sixth rectifying diode D6. The anode of the first rectifying diode D1 is connected to the first input terminal T of the rectifying circuit 20, the cathode of the first rectifying diode D1 is connected to the first output terminal of the rectifying circuit 20, the cathode of the fourth rectifying diode D4 is connected to the first input terminal T of the rectifying circuit 20, and the anode of the fourth rectifying diode D4 is connected to the second output terminal of the rectifying circuit 20; the anode of the second rectifying diode D2 is connected to the second input terminal S of the rectifying circuit 20, the cathode of the second rectifying diode D2 is connected to the first output terminal of the rectifying circuit 20, the cathode of the fifth rectifying diode D5 is connected to the second input terminal S of the rectifying circuit 20, and the anode of the fifth rectifying diode D5 is connected to the second output terminal of the rectifying circuit 20; the anode of the third rectifying diode D3 is connected to the third input terminal R of the rectifying circuit 20, the cathode of the third rectifying diode D3 is connected to the first output terminal of the rectifying circuit 20, the cathode of the sixth rectifying diode D6 is connected to the third input terminal R of the rectifying circuit 20, and the anode of the sixth rectifying diode D6 is connected to the second output terminal of the rectifying circuit 20. The first input end T of the rectifying circuit 20, the second input end S of the rectifying circuit 20 and the third input end R of the rectifying circuit 20 are all used for connecting an external power supply; the buffer circuit 70 is connected in series between the first output terminal of the rectifier circuit 20 and the positive dc bus 81, and the second output terminal of the rectifier circuit 20 is connected to the negative dc bus 82, or the buffer circuit 70 is connected in series between the second output terminal of the rectifier circuit 20 and the negative dc bus 81, and the first output terminal of the rectifier circuit 20 is connected to the positive dc bus 81. The rectified current is connected with an external power supply in a three-phase mode, then is rectified through six rectifying diodes, and can convert the first alternating current of the external power supply into a first direct current.
In some embodiments, referring to fig. 4, the snubber circuit 70 includes a snubber resistor R5 and a contactor U1 connected in parallel, that is, a first end of the snubber resistor R5 is connected to a first end of the contactor U1, a second end of the snubber resistor R5 is connected to a second end of the contactor U1, a third end of the contactor U1 is further connected to a third end of the control unit, the control unit is further configured to output a second control signal, and the contactor U1 is configured to control the operation of the snubber resistor R5 according to the second control signal. Specifically, the first end of the contactor is further connected to the first output end of the rectifying circuit, and the second end of the contactor is further connected to the positive dc bus, or, referring to fig. 4 again, the first end of the contactor U1 is further connected to the second output end of the rectifying circuit 20, and the second end of the contactor U1 is further connected to the negative dc bus 82. When the frequency converter 100 is powered on, the control unit controls the contactor U1 to be disconnected, at the moment, the buffer resistor R5 starts to work, the current with large ripple waves when the energy storage circuit 30 starts to charge can be restrained, after the energy storage circuit 30 finishes charging, the control unit controls the contactor U1 to be closed, the buffer resistor R5 is in short circuit, and the buffer resistor R5 does not work.
In some embodiments, the energy storage circuit comprises at least one electrolytic capacitor bank connected in series, and the electrolytic capacitor bank is formed by connecting an electrolytic capacitor and a voltage dividing resistor in parallel. Specifically, referring to fig. 4, the energy storage circuit 30 includes a first electrolytic capacitor group, a second electrolytic capacitor group, and a third electrolytic capacitor group, the first electrolytic capacitor group, the second electrolytic capacitor group, and the third electrolytic capacitor group are sequentially connected in series to form the energy storage circuit 30, the first electrolytic capacitor group is formed by connecting a first capacitor C1 and a first resistor R1 in parallel, the second electrolytic capacitor group is formed by connecting a second capacitor C2 and a second resistor R2 in parallel, and the third electrolytic capacitor group is formed by connecting a third capacitor C3 and a third resistor R3 in parallel. In practical applications, the number of the electrolytic capacitor sets can be set according to actual needs, and is not limited to the limitations in the embodiment.
In some embodiments, referring to fig. 4, the inverter circuit 40 has a first input terminal, a second input terminal, a first output terminal U, a second output terminal V and a third output terminal W, and the inverter circuit 40 includes a second IGBT transistor Q2, a third IGBT transistor Q3, a fourth IGBT transistor Q4, a fifth IGBT transistor Q5, a sixth IGBT transistor Q6 and a seventh IGBT transistor Q7. A collector of a second IGBT Q2 is connected to the first input terminal of the inverter circuit 40, an emitter of the second IGBT Q2 is connected to the first output terminal U of the inverter circuit 40, a collector of a fifth IGBT Q5 is connected to the first output terminal U of the inverter circuit 40, and an emitter of the fifth IGBT Q5 is connected to the second input terminal of the inverter circuit 40; the collector of a third IGBT Q3 is connected to the first input terminal of the inverter circuit 40, the emitter of the third IGBT Q3 is connected to the second output terminal V of the inverter circuit 40, the collector of a sixth IGBT Q6 is connected to the second output terminal V of the inverter circuit 40, and the emitter of the sixth IGBT Q6 is connected to the second input terminal of the inverter circuit 40; the collector of the fourth IGBT Q4 is connected to the first input terminal of the inverter circuit 40, the emitter of the fourth IGBT Q4 is connected to the third output terminal W of the inverter circuit 40, the collector of the seventh IGBT Q7 is connected to the third output terminal W of the inverter circuit 40, and the emitter of the seventh IGBT Q7 is connected to the second input terminal of the inverter circuit 40. A first input end of the inverter circuit 40 is connected with the positive direct current bus 81, and a second input end of the inverter circuit 40 is connected with the negative direct current bus 82; the first output end U of the inverter circuit 40, the second output end V of the inverter circuit 40, and the third output end W of the inverter circuit 40 are all used for connecting with an external device. The gate of the second IGBT tube Q2 is connected to the fourth end of the control unit, the gate of the third IGBT tube Q3 is connected to the fifth end of the control unit, the sixth end of the fourth IGBT tube Q4 is connected to the control unit, the seventh end of the fifth IGBT tube Q5 is connected to the control unit, the eighth end of the sixth IGBT tube Q6 is connected to the control unit, and the ninth end of the seventh IGBT tube Q7 is connected to the control unit.
The embodiment of the utility model provides a frequency converter, which comprises a box body, a rectifying circuit, an energy storage circuit, a switch unit, a brake unit, an inverter circuit and a control unit, wherein the box body is provided with a first end and a second end; the box body is provided with an accommodating space, the rectifying circuit, the energy storage circuit, the switch unit, the inverter circuit and the control unit are accommodated in the accommodating space, and the brake unit is arranged outside the box body; through at the inside integrated switch unit of converter, closed switch when the tank circuit voltage is too high, the brake unit begins to work, thereby realize the braking, in addition, because the switch unit is integrated inside the converter, can form simple control circuit structure through concatenating the switch unit between main circuit and brake unit, with this control to the brake unit of realization, set up in the complicated control circuit that the box outside formed for the switch unit, the control circuit structure is simpler, thereby can reduce the volume of whole equipment, and the cost is lower.
It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple 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 examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the utility model, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the utility model as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A frequency converter, comprising: the brake device comprises a box body, a rectifying circuit, an energy storage circuit, a switch unit, a brake unit, an inverter circuit and a control unit;
the box body is provided with an accommodating space, the rectifying circuit, the energy storage circuit, the switch unit, the inverter circuit and the control unit are accommodated in the accommodating space, and the brake unit is arranged outside the box body;
the rectification circuit, the energy storage circuit and the inverter circuit are connected in sequence;
the switch unit is connected with the brake unit to form a brake circuit, the brake circuit is connected in series between the energy storage circuit and the inverter circuit, the switch unit is further connected with a first end of the control unit, the control unit is used for outputting a first control signal to the switch unit when the voltage of the energy storage circuit is too high, and the switch unit is used for controlling the brake unit to work according to the first control signal.
2. The frequency converter of claim 1, further comprising a snubber circuit, a positive dc bus, and a negative dc bus;
the buffer circuit, the positive direct current bus and the negative direct current bus are contained in the containing space;
the first end of the rectifying circuit is connected with the first end of the inverter circuit through the positive direct current bus, and the second end of the rectifying circuit is connected with the second end of the inverter circuit through the negative direct current bus;
the third end of the rectifying circuit is used for connecting an external power supply, and the rectifying circuit is used for converting the first alternating current of the external power supply into a first direct current;
the third end of the inverter circuit is used for connecting an external device, and the inverter circuit is used for converting the first direct current into a second alternating current and outputting the second alternating current to the external device;
the energy storage circuit is connected in series between the positive direct current bus and the negative direct current bus, is arranged between the rectifying circuit and the inverter circuit, and is used for storing the first direct current;
the buffer circuit is connected in series between the rectifying circuit and the positive direct-current bus, or the buffer circuit is connected in series between the rectifying circuit and the negative direct-current bus, and the buffer circuit is used for electrically buffering the frequency converter.
3. The frequency converter according to claim 2, wherein the switching unit is a first IGBT tube, a collector of the first IGBT tube is connected to the positive dc bus, an emitter of the first IGBT tube is connected to the first end of the braking unit, a gate of the first IGBT tube is connected to the first end of the control unit, and a second end of the braking unit is connected to the negative dc bus.
4. The frequency converter according to claim 3, wherein the braking unit is a braking resistor.
5. The frequency converter according to any one of claims 2-4, characterized in that the voltage of the first alternating current is in the range of 520V-690V and the output power of the frequency converter is 37 KW.
6. The frequency converter according to any one of claims 2-4, characterized in that the frequency converter further comprises a voltage detection unit;
the first end of the voltage detection unit is connected with the energy storage circuit, the second end of the voltage detection unit is connected with the second end of the control unit, the voltage detection unit is used for detecting the voltage of the energy storage circuit and outputting the voltage to the control unit, and the control unit is used for outputting the first control signal according to the voltage.
7. The frequency converter according to any one of claims 2 to 4, wherein the rectifying circuit has a first input terminal, a second input terminal, a third input terminal, a first output terminal and a second output terminal, and the rectifying circuit includes a first rectifying diode, a second rectifying diode, a third rectifying diode, a fourth rectifying diode, a fifth rectifying diode and a sixth rectifying diode;
the anode of the first rectifying diode is connected with the first input end of the rectifying circuit, the cathode of the first rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the fourth rectifying diode is connected with the first input end of the rectifying circuit, and the anode of the fourth rectifying diode is connected with the second output end of the rectifying circuit;
the anode of the second rectifying diode is connected with the second input end of the rectifying circuit, the cathode of the second rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the fifth rectifying diode is connected with the second input end of the rectifying circuit, and the anode of the fifth rectifying diode is connected with the second output end of the rectifying circuit;
the anode of the third rectifying diode is connected with the third input end of the rectifying circuit, the cathode of the third rectifying diode is connected with the first output end of the rectifying circuit, the cathode of the sixth rectifying diode is connected with the third input end of the rectifying circuit, and the anode of the sixth rectifying diode is connected with the second output end of the rectifying circuit;
the first input end of the rectifying circuit, the second input end of the rectifying circuit and the third input end of the rectifying circuit are all used for being connected with the external power supply;
the buffer circuit is connected in series between the first output end of the rectifying circuit and the positive direct-current bus, the second output end of the rectifying circuit is connected with the negative direct-current bus, or the buffer circuit is connected in series between the second output end of the rectifying circuit and the negative rectifying bus, and the first output end of the rectifying circuit is connected with the positive direct-current bus.
8. The frequency converter according to claim 7, wherein the snubber circuit comprises a snubber resistor and a contactor connected in parallel;
the contactor is further connected with a third end of the control unit, the control unit is further used for outputting a second control signal, and the contactor is used for controlling the buffer resistor to work according to the second control signal.
9. The frequency converter according to claim 8, wherein the energy storage circuit comprises at least one electrolytic capacitor bank connected in series, and the electrolytic capacitor bank is composed of an electrolytic capacitor and a voltage dividing resistor connected in parallel.
10. The frequency converter according to claim 9, wherein the inverter circuit has a first input terminal, a second input terminal, a first output terminal, a second output terminal and a third output terminal, and the inverter circuit comprises a second IGBT tube, a third IGBT tube, a fourth IGBT tube, a fifth IGBT tube, a sixth IGBT tube and a seventh IGBT tube;
a collector of the second IGBT tube is connected with a first input end of the inverter circuit, an emitter of the second IGBT tube is connected with a first output end of the inverter circuit, a collector of the fifth IGBT tube is connected with a first output end of the inverter circuit, and an emitter of the fifth IGBT tube is connected with a second input end of the inverter circuit;
a collector of the third IGBT tube is connected with a first input end of the inverter circuit, an emitter of the third IGBT tube is connected with a second output end of the inverter circuit, a collector of the sixth IGBT tube is connected with a second output end of the inverter circuit, and an emitter of the sixth IGBT tube is connected with a second input end of the inverter circuit;
a collector electrode of the fourth IGBT tube is connected with the first input end of the inverter circuit, an emitter electrode of the fourth IGBT tube is connected with the third output end of the inverter circuit, a collector electrode of the seventh IGBT tube is connected with the third output end of the inverter circuit, and an emitter electrode of the seventh IGBT tube is connected with the second input end of the inverter circuit;
a first input end of the inverter circuit is connected with the positive direct-current bus, and a second input end of the inverter circuit is connected with the negative direct-current bus;
the first output end of the inverter circuit, the second output end of the inverter circuit and the third output end of the inverter circuit are all used for being connected with the external equipment;
the gate pole of the second IGBT tube is connected with the fourth end of the control unit, the fifth end of the third IGBT tube is connected with the fifth end of the control unit, the sixth end of the fourth IGBT tube is connected with the sixth end of the control unit, the seventh end of the fifth IGBT tube is connected with the seventh end of the control unit, the eighth end of the sixth IGBT tube is connected with the eighth end of the control unit, and the seventh IGBT tube is connected with the ninth end of the control unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121226484.3U CN215817938U (en) | 2021-06-02 | 2021-06-02 | Frequency converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121226484.3U CN215817938U (en) | 2021-06-02 | 2021-06-02 | Frequency converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215817938U true CN215817938U (en) | 2022-02-11 |
Family
ID=80174971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121226484.3U Active CN215817938U (en) | 2021-06-02 | 2021-06-02 | Frequency converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215817938U (en) |
-
2021
- 2021-06-02 CN CN202121226484.3U patent/CN215817938U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3343749A1 (en) | Multi-level inverter | |
| CN106803721A (en) | PMSM Drive System no electrolytic capacitor power inverter and control method | |
| CN108141147B (en) | The five-electrical level inverter topological circuit of high voltage gain | |
| CN113489326A (en) | Two-stage DC/AC bidirectional conversion device applied to energy router | |
| CN215817938U (en) | Frequency converter | |
| CN111884523B (en) | Power conversion system | |
| CN211296551U (en) | Compatible alternating current-direct current output control circuit and vehicle-mounted equipment | |
| CN201956913U (en) | Integral switched reluctance motor drive and charging governing device | |
| CN107769600B (en) | Asymmetric multi-level power conversion circuit | |
| CN117411155A (en) | Charging device, charging pile and charging system | |
| CN206344713U (en) | A kind of electric vehicle motor controller charge/discharge control circuit | |
| CN209748405U (en) | Household electrical appliance and passive power factor correction circuit thereof | |
| CN212413080U (en) | Motor drive circuit, motor control circuit and air conditioner | |
| CN110729896B (en) | Bidirectional direct current converter based on MMC and control system thereof | |
| CN212061818U (en) | Display device | |
| CN210327378U (en) | Current conversion circuit and charging device | |
| CN208820711U (en) | A kind of frequency converter | |
| CN110707955A (en) | Three-phase multi-level inverter circuit | |
| CN214799333U (en) | Motor drive circuit, motor and household electrical appliance | |
| CN215897595U (en) | Low-cost pre-charging system of three-phase high-power frequency converter | |
| CN214851025U (en) | Motor drive circuit, motor and household electrical appliance | |
| CN213717915U (en) | Solar grid-connected inverter | |
| CN214045480U (en) | Permanent magnet synchronous motor control system adopting improved direct torque control technology | |
| CN215601206U (en) | Power supply circuit, circuit board and electrical apparatus | |
| CN212726880U (en) | Self-taking control power supply device of voltage source type converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |