High-frequency steady-current and steady-voltage direct-current power supply

Abstract

The utility model provides a high-frequency current-stabilizing and voltage-stabilizing direct-current power supply, which comprises an output circuit which is used for converting three-phase alternating current into high-frequency direct current and outputting the high-frequency direct current and comprises a three-phase power input module, a first rectifying and filtering module, an IGBT (Insulated Gate Bipolar Translator) inverter module, a transformer, a second rectifying and filtering module, a shunt and an output module which are electrically connected in sequence; the PWM control module and the IGBT driving circuit are used for driving the IGBT inverter module and comprise a detection module, a protection module and an IGBT driving module; wherein when the detection module detects that an abnormal signal is received, the protection module outputs a low level, and the IGBT driving module drives the IGBT inverter module to be in a turn-off state; and when the abnormal signal detected by the detection module disappears, the protection module outputs a high level, and the IGBT driving module drives the IGBT inverter module to be in an output state.

Description

Technical Field

[0001] The present application discloses a current conversion circuit, and in particular relates to a high-frequency, current-stabilized and voltage-stabilized direct current power supply. Background Art

[0002] High-frequency, current-stabilized and voltage-stabilized DC power supplies are suitable for electrolysis, electroplating, electrochemistry and other fields that require high-quality DC power supplies that periodically change the direction of current output. Existing DC power supplies achieve self-protection by powering off after a fault occurs, such as overcurrent or overcurrent, but lack the function of restarting and restoring power after a power outage. Manual power-on is required, which is not convenient or intelligent enough. Improvements are proposed. Utility Model Content

[0003] The utility model provides a new high-frequency current-stabilized and voltage-stabilized DC power supply to solve the defects of the prior art, such as the need for manual power-on to restore power supply after self-protection power failure, which is not convenient and intelligent enough.

[0004] In order to solve the above technical problems, the utility model is implemented through the following technical solutions:

[0005] A high-frequency, current-stabilized, voltage-stabilized DC power supply, used to convert AC power in a three-phase power grid into high-frequency DC output, comprising:

[0006] The output circuit converts the three-phase AC power into a high-frequency DC power output, and includes a three-phase power input module, a first rectifier and filter module, an IGBT inverter module, a transformer, a second rectifier and filter module, a shunt, and an output module which are electrically connected in sequence;

[0007] PWM control module, used to control the output and shutdown state of the IGBT inverter module;

[0008] An IGBT drive circuit, controlled by a PWM control module and used to drive the IGBT inverter module, includes a detection module, a protection module, and an IGBT drive module;

[0009] A detection module, used to detect abnormal signals of voltage and current values ​​output by the IGBT inverter module;

[0010] A protection module, cooperating with the IGBT drive module to control the output and shutdown of the IGBT inverter module;

[0011] Among them, when the detection module detects that it has received an abnormal signal, the protection module outputs a low level, and the IGBT drive module drives the IGBT inverter module to be in an off state; when the abnormal signal detected by the detection module disappears, the protection module outputs a high level, and the IGBT drive module drives the IGBT inverter module to be in an output state.

[0012] In the present application, the IGBT inverter module is driven by the IGBT drive circuit to work, and the IGBT drive circuit is controlled by the PWM control module. The IGBT drive circuit cooperates with the detection module and the protection module to enable the DC power supply in the present application to have the functions of self-power-off and self-starting.

[0013] Specifically, when the detection module detects an abnormal signal, the protection module drives the IGBT inverter module to be in a shutdown state; when the abnormal signal detected by the detection module disappears, the protection module drives the IGBT inverter module to be in an output state, thereby solving the problem in the prior art that the DC power supply needs to be manually powered on after power failure.

[0014] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0015] Optionally, the PWM control module includes a PWM controller chip, a latch chip, and a voltage level converter chip that cooperate with each other, the OUTPUTA pin on the PWM controller chip is connected to the S2 pin on the latch chip, the OUTPUTB pin on the PWM controller chip is connected to the S1 pin on the latch chip, the VREF pin on the PWM controller chip is connected to the SELECT pin on the voltage level converter chip, and the OSC OUTPUT pin on the PWM controller chip is connected to the FIN pin on the voltage level converter chip.

[0016] Optionally, the CT pin and the DISCHARGE pin on the PWM controller chip are connected, and a resistor R166 is connected in series to adjust the dead time.

[0017] Optionally, a C-SOFT START pin on the PWM controller chip is connected to a timing capacitor C151 for controlling the soft start of the PWM controller chip.

[0018] Optionally, the detection module adopts an M57962AL driver chip.

[0019] Optionally, the protection module adopts an optical coupler. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a module diagram of this application;

[0021] Figure 2 A circuit diagram of a PWM control module in an embodiment of the present application;

[0022] Figure 3 A circuit diagram of an IGBT driving circuit in an embodiment of the present application;

[0023] Figure 4 for Figure 3 Local zoom in Figure 1 ;

[0024] Figure 5 for Figure 3 Local zoom in Figure 2 .

[0025] Description of the reference numerals is as follows:

[0026] 1. PWM controller chip; 2. Voltage level converter chip; 3. Latch chip; 4. Timing capacitor C151; 5. Resistor R166; 6. Detection module; 7. Protection module; 8. IGBT drive module. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be a central component. When a component is referred to as being "disposed on" another component, it may be directly disposed on the other component or there may be a central component at the same time.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0030] refer to Figure 1-Figure 5 In one embodiment of the present application, a high-frequency current-stabilized voltage-stabilized DC power supply is disclosed, which is used to convert AC power in a three-phase power grid into high-frequency DC power output, including:

[0031] The output circuit converts the three-phase alternating current into a high-frequency direct current output (specifically, the high-frequency direct current is direct current of 5000 Hz or above), and includes a three-phase power input module, a first rectifier and filter module, an IGBT inverter module, a transformer, a second rectifier and filter module, a shunt, and an output module which are electrically connected in sequence;

[0032] The three-phase alternating current from the external three-phase power grid is input through the three-phase power input module, converted into direct current through the first rectifier and filter module, and then the direct current waveform is modulated through the PWM control module in cooperation with the IGBT inverter module, and then output after voltage transformation by the transformer and voltage stabilization, voltage limiting, current stabilization, and current limiting by the second rectifier and filter module.

[0033] PWM control module, used to control the output and shutdown state of the IGBT inverter module;

[0034] The IGBT drive circuit is controlled by the PWM control module and is used to drive the IGBT inverter module, including a detection module, a protection module, and an IGBT drive module;

[0035] A detection module, used to detect abnormal signals of voltage and current values ​​output by the IGBT inverter module;

[0036] The protection module cooperates with the IGBT drive module to control the output and shutdown of the IGBT inverter module;

[0037] Among them, when the detection module detects an abnormal signal, the protection module outputs a low level, and the IGBT drive module drives the IGBT inverter module to be in the off state; when the abnormal signal detected by the detection module disappears, the protection module outputs a high level, and the IGBT drive module drives the IGBT inverter module to be in the output state.

[0038] Preferably, the PWM control module includes a PWM controller chip, a latch chip, and a voltage level converter chip that cooperate with each other, the OUTPUTA pin on the PWM controller chip is connected to the S2 pin on the latch chip, the OUTPUTB pin on the PWM controller chip is connected to the S1 pin on the latch chip, the VREF pin on the PWM controller chip is connected to the SELECT pin on the voltage level converter chip, and the OSC OUTPUT pin on the PWM controller chip is connected to the FIN pin on the voltage level converter chip.

[0039] Preferably, the CT pin and the DISCHARGE pin on the PWM controller chip are connected, and a resistor R166 is connected in series to adjust the dead time.

[0040] Preferably, a C-SOFT START pin on the PWM controller chip is connected to a timing capacitor C151 for controlling the soft start of the PWM controller chip.

[0041] Preferably, the detection module adopts the M57962AL driver chip.

[0042] Preferably, the protection module adopts an optical coupler.

[0043] refer to Figure 2 In some embodiments of the present application, the PWM controller chip uses the KA3525A chip, and the timing capacitor C151 is connected to the C-SOFT START pin to control the soft start of the PWM controller chip.

[0044] During the power-on process, since the voltage across capacitor C151 cannot change suddenly, the reverse input of the PWM comparator connected to the access end of capacitor C151 is at a low level, and the PWM comparator outputs a high level. At this time, the output of the latch chip is also a high level, which is added to the output transistor through two NOR gates to prevent it from conducting. Only when capacitor C151 is charged to a voltage that makes the C-SOFT START pin at a high level, KA3525A starts to work.

[0045] Specifically, the sampling voltage of the output module is added to the pin of the error amplifier, that is, the EA+ pin (pin 2) of the PWM controller chip. When the output voltage increases due to an increase in the input voltage or a change in the load, the output of the error amplifier will decrease, which will cause the PWM comparator output to be positive for a longer time, and the PWM latch to output a high level for a longer time, so the on-time of the output transistor will eventually become shorter, so that the output voltage falls back to the rated value and a steady state is achieved. Vice versa. The external shutdown signal works on both the output stage and the soft start circuit. When the signal on the SHUT DOWN pin (pin 10) is high, the PWM latch will immediately act to disable the output of KA3525A, and at the same time, the soft start capacitor will begin to discharge. If the high level continues, the soft start capacitor will be fully discharged until the shutdown signal ends, and then the soft start process will be re-entered.

[0046] The PMW signal generated by the PWM controller chip is maintained and reversely output through the latch chip, and the output signal is given to the IGBT drive circuit to control the upper and lower bridge arms of the IGBT respectively, so as to avoid the "red crossover" phenomenon. The PWM signal passes through the latch chip logic interlock control circuit to eliminate mis-conduction and overcome the short circuit phenomenon caused by mis-conduction of the bridge arm.

[0047] Further, the voltage level converter chip adopts CD4504B chip, which is a hexadecimal voltage level converter composed of six circuits, which shift the input signal from VCC logic level to VDD logic level. To shift the TTL signal to CMOS logic level, the SELECT input is in VCC HIGH logic state. When the SELECT input is in low logic state, each circuit converts the signal from one CMOS level to another CMOS level.

[0048] refer to Figure 3-Figure 5 , Figure 5For the IGBT circuit of the present application, in some embodiments of the present application, the IGBT driving circuit includes a detection module, a protection module, and an IGBT driving module, which can respond quickly but slowly shut down the IGBT when overcurrent occurs, and give a fault signal to the external circuit. The detection module is an M57962AL driver chip, and the protection module uses an optical coupler.

[0049] When the voltage of the input terminal (pin 1) of the M57962AL driver chip is detected to be 7V, it is determined that the circuit is short-circuited, and the shutdown signal is immediately output through the optical coupler, so that the output terminal (pin 5) outputs a low level to negatively bias the gate and emitter of the IGBT, so that the IGBT can be reliably turned off. At the same time, the fault signal is output to make the fault output terminal (pin 8) low level, thereby driving the external protection circuit to work. After a delay of 2 to 3 seconds, if the pin 13 is detected to be high level, the M57962AL resumes work.

[0050] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made within the scope of the patent application for the present invention should fall within the scope of the present invention.

Claims

1. A high-frequency, current-stabilized, voltage-stabilized DC power supply, used to convert AC power in a three-phase power grid into high-frequency DC power output, characterized in that: include: The output circuit converts the three-phase AC power into a high-frequency DC power output, and includes a three-phase power input module, a first rectifier and filter module, an IGBT inverter module, a transformer, a second rectifier and filter module, a shunt, and an output module which are electrically connected in sequence; PWM control module, used to control the output and shutdown state of the IGBT inverter module; An IGBT drive circuit, controlled by a PWM control module and used to drive the IGBT inverter module, includes a detection module, a protection module, and an IGBT drive module; A detection module, used to detect abnormal signals of voltage and current values ​​output by the IGBT inverter module; A protection module, cooperating with the IGBT drive module to control the output and shutdown of the IGBT inverter module; Among them, when the detection module detects that it has received an abnormal signal, the protection module outputs a low level, and the IGBT drive module drives the IGBT inverter module to be in an off state; when the abnormal signal detected by the detection module disappears, the protection module outputs a high level, and the IGBT drive module drives the IGBT inverter module to be in an output state.

2. A high-frequency, current-stabilized and voltage-stabilized DC power supply according to claim 1, characterized in that: The PWM control module includes a PWM controller chip, a latch chip, and a voltage level converter chip that cooperate with each other. The OUTPUTA pin on the PWM controller chip is connected to the S2 pin on the latch chip, the OUTPUTB pin on the PWM controller chip is connected to the S1 pin on the latch chip, the VREF pin on the PWM controller chip is connected to the SELECT pin on the voltage level converter chip, and the OSC OUTPUT pin on the PWM controller chip is connected to the FIN pin on the voltage level converter chip.

3. A high-frequency, current-stabilized and voltage-stabilized DC power supply according to claim 2, characterized in that: The CT pin and the DISCHARGE pin on the PWM controller chip are connected, and a resistor R166 is connected in series to adjust the dead time.

4. A high-frequency, current-stabilized and voltage-stabilized DC power supply according to claim 2, characterized in that: The C-SOFT START pin on the PWM controller chip is connected to a timing capacitor C151 for controlling the soft start of the PWM controller chip.

5. A high-frequency, current-stabilized and voltage-stabilized DC power supply according to claim 2, characterized in that: The detection module adopts the M57962AL driver chip.

6. A high-frequency current-stabilized and voltage-stabilized DC power supply according to claim 5, characterized in that: The protection module adopts an optical coupler.

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