Output-adjustable isolation driving power supply circuit with wide input voltage range

Abstract

According to the adjustable output isolation driving power supply circuit with the wide input voltage range, the first-stage DC-DC conversion circuit inputs a wide-range first voltage signal, converts the wide-range first voltage signal into a stable second DC voltage signal, and outputs the stable second DC voltage signal to the second-stage isolation DC-DC conversion circuit, so that a wider input power supply range can be realized; the second-stage isolation DC-DC conversion circuit converts the second DC voltage signal into a third DC voltage signal and outputs the third DC voltage signal to the high-precision voltage stabilizing circuit; the high-precision voltage stabilizing circuit takes an LT431 voltage reference chip as a core, and outputs stable direct-current positive voltage signals and negative voltage signals through feedback voltage regulation of the regulating circuit, so that high-precision, simple and adjustable driving output voltage can be realized.

Description

Technical Field

[0001] The invention relates to a power electronic power converter, in particular to an adjustable output isolation driving power supply circuit with a wide input voltage range. Background Art

[0002] At present, for the switch tubes (IGBT, MOS, SiC, GaN, etc.; hereinafter referred to as: switch tubes), in order to reduce the design and manufacturing costs, the traditional power converter driving power supply scheme mostly adopts a one-stage DCDC conversion driving power supply circuit; however, this one-stage driving power supply circuit cannot achieve high-precision driving voltage output, and the input operating voltage range is very narrow, which makes it susceptible to input power fluctuations, thereby affecting the stability and reliability of the switch tube operation; when this one-stage driving power supply circuit performs multi-stage driving output, there is a problem of large output voltage deviation, and the driving output voltage deviation will affect the consistency of the switch tube on and off, especially in the case of multi-stage parallel switching tubes, which will affect the effect of the switch tube current sharing, thereby reducing the service life of the switch tube, and more seriously, it may cause one of the switch tubes to be damaged due to long-term non-current sharing; therefore, it is particularly important to improve the power supply adaptability and driving output voltage accuracy of the driving power supply. Summary of the invention

[0003] The problem to be solved by the present invention is to provide an adjustable output isolation driving power supply circuit with a wide input voltage range, so as to solve the problem that the existing driving power supply circuit of the first-level DC-DC conversion has a narrow operating voltage range and a large output voltage deviation.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: comprising a primary DC-DC conversion circuit, a secondary isolated DC-DC conversion circuit and a high-precision voltage stabilization circuit, wherein the primary DC-DC conversion circuit inputs a first voltage signal in a wide range, converts it into a stable second DC voltage signal, and outputs it to the secondary isolated DC-DC conversion circuit; The secondary isolated DC-DC conversion circuit converts the second DC voltage signal into a third DC voltage signal and outputs it to a high-precision voltage stabilization circuit; The high-precision voltage stabilization circuit outputs stable direct current positive voltage signals and negative voltage signals through high-precision voltage stabilization and voltage regulation.

[0005] Preferably, the first-stage DC-DC conversion circuit includes a DC-DC control chip, an input filter circuit, an energy storage filter circuit, a feedback regulation circuit and a frequency compensation circuit; The input filter circuit receives a first voltage signal in a wide range and performs filtering, and after filtering, supplies power to the DC-DC control chip; The DC-DC control chip inputs the filtered signal and outputs the required second DC voltage signal by adjusting the switching logic and duty cycle of the internal switch tube; The second DC voltage signal enters the energy storage filter circuit to store energy and reduce the switching ripple of the output voltage, and output a stable second DC voltage signal; The feedback regulation circuit collects a stable second DC voltage signal and feeds it back to the DC-DC control chip to stabilize the second DC voltage signal; The frequency compensation circuit is connected to the DC-DC control chip to compensate for the internal operating frequency of the DC-DC control chip.

[0006] Preferably, the secondary isolated DC-DC conversion circuit includes a PWM control circuit, a half-bridge conversion circuit, a high-frequency isolation transformer and a rectifier and filter circuit; The half-bridge conversion circuit is connected to the stable second DC voltage signal, amplified and converted into an AC voltage signal, the AC voltage signal is electrically isolated by a high-frequency isolation transformer, and finally rectified and filtered by a rectifier and filter circuit to output a stable third DC voltage signal; The PWM control circuit is powered by the second DC voltage signal and is used to output a PWM control signal to control the half-bridge conversion circuit.

[0007] Preferably, the high-precision voltage stabilization circuit includes a high-precision voltage stabilizer and a voltage adjustment circuit. The voltage stabilization circuit is connected to the stable third DC voltage signal, and uses a voltage reference chip to stabilize and output stable positive voltage signals and negative voltage signals. The positive voltage signal and the negative voltage signal are collected by the voltage adjustment circuit and fed back to the voltage reference chip.

[0008] The beneficial effects of the present invention are as follows: 1. Compared with the traditional one-stage driving power supply circuit, the present application adds a one-stage DC-DC conversion circuit with a wide voltage range, which can achieve a wider input voltage working range, effectively reduce the impact of input power supply fluctuations on the driving output, and improve the stability and reliability of the system operation.

[0009] 2. The present application optimizes and improves the traditional driving circuit, and changes the output Zener diode as a voltage regulator to an LT431 voltage reference chip as a voltage regulator to stabilize the output positive voltage, thereby improving the output voltage accuracy of the driving power supply, and for multi-stage parallel switching tubes, effectively improving the switching consistency and current sharing effect of the switching tubes.

[0010] 3. The present application can realize high-precision and simple adjustment of the driving output voltage, which improves the flexibility of its application compared with the traditional driving power supply solution composed of an unadjustable voltage stabilizing circuit; since different manufacturers or different types of switching tubes work under different load conditions, their optimal driving operating voltages are also different. Adjusting to the optimal driving voltage can effectively reduce switching losses and the risk of explosion, and increase the service life of the switching tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the overall circuit diagram of the present invention.

[0012] Figure 2 This is a block diagram of a first-level DC-DC conversion circuit of the present invention.

[0013] Figure 3 This is a schematic diagram of a first-level DC-DC conversion circuit of the present invention.

[0014] Figure 4 The figure is a block diagram of the secondary isolation DC-DC conversion circuit of the present invention.

[0015] Figure 5 This is a schematic diagram of the secondary isolation DC-DC conversion circuit of the present invention.

[0016] Figure 6 This is a block diagram of the high-precision voltage stabilizing circuit of the present invention.

[0017] Figure 7 This is a schematic diagram of the high-precision voltage stabilizing circuit of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions of various embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] The following is in conjunction with the instruction manual Figure 1 To Attachment Figure 7 , the specific implementation modes of the present invention are further described in detail.

[0020] Embodiment 1, an adjustable output isolation driving power supply circuit with a wide input voltage range, see Figure 1 , comprising a primary DC-DC conversion circuit 10, a secondary isolated DC-DC conversion circuit 20 and a high-precision voltage stabilization circuit 30, wherein the primary DC-DC conversion circuit 10 inputs a first voltage signal in a wide range, converts it into a stable second DC voltage signal, and outputs it to the secondary isolated DC-DC conversion circuit 20; The secondary isolation DC-DC conversion circuit 20 converts the second DC voltage signal into a third DC voltage signal, realizes electrical isolation, and outputs it to a high-precision voltage stabilization circuit; The high-precision voltage stabilization circuit outputs stable DC positive voltage signals and negative voltage signals through high-precision voltage stabilization and regulation to drive the subsequent switch tube. Compared with the traditional driving power supply solution composed of an unadjustable voltage stabilization circuit, the present application can achieve adjustable output positive and negative voltages, thereby improving the flexibility of the driving power supply circuit. Since the switch tubes of different manufacturers or different types work under different load conditions, their optimal driving working voltages are also different. Adjusting to the optimal driving voltage can effectively reduce the switching loss and the risk of explosion, thereby improving the service life of the switch tube. Example 2, based on Example 1, see Figure 2 The first-level DC-DC conversion circuit 10 includes a DC-DC control chip 12, an input filter circuit 11, an energy storage filter circuit 15, a feedback adjustment circuit 13 and a frequency compensation circuit 14; See also Figure 3 The input filter circuit 11 receives a first voltage signal in a wide range, and is filtered by capacitors C1 and C2, and then supplies power to the DC-DC control chip 12 after filtering; The DC-DC control chip 12 inputs the filtered signal, which is specifically connected to the VCC pin of the chip U1, and outputs the required second DC voltage signal by adjusting the switching logic and duty cycle of its internal switch tube; The second DC voltage signal enters the energy storage filter circuit 15, and the diode D1, the inductor L1, the capacitors C3 and C4 store energy and reduce the switching ripple of the output voltage, and output a stable second DC voltage signal; The feedback regulation circuit 13 collects a stable second DC voltage signal through the resistors R1 and R2, and feeds it back to the DC-DC control chip after voltage division to stabilize the second DC voltage signal; The frequency compensation circuit 14 includes capacitors C5 and C6 and resistors R3 and R7, which are configured at the COMP pin of the DC-DC control chip U1 to compensate for the internal operating frequency of the DC-DC control chip 12 and further improve the stability of the second output voltage.

[0021] Example 3, based on Example 1, see Figure 4 The secondary isolation DC-DC conversion circuit 20 includes a PWM control circuit 22, a half-bridge conversion circuit 21, a high-frequency isolation transformer 23 and a rectifier filter circuit 24; The half-bridge conversion circuit 21 is connected to the stable second DC voltage signal, including transistors Q1, Q3, capacitor C15, diodes D3 and D8. The figure shows a half-bridge topology composed of transistors, which can also be a half-bridge topology composed of MOS tubes. It is amplified and converted into an AC voltage signal. The AC voltage signal is electrically isolated by the high-frequency isolation transformer 23. The secondary coil of the high-frequency isolation transformer 23 outputs two groups of isolated AC voltage signals, and finally rectified and filtered by the rectifier and filter circuit 24 to output a stable third DC voltage signal. See Figure 5 Since the rectification, filtering and high-precision voltage stabilization structures of the isolated AC voltage signal are the same, the following is a detailed description of the first circuit. The setting adopts capacitor C16, diodes D9 and D10 voltage doubling rectification circuit, and capacitors C17, C18, C23 and C24 filtering circuit filtering; The PWM control circuit 22 includes a PWM control chip U2, resistors R4, R5, R6, R8, R9, R10, R12, R13, R14, capacitors C11, C12, C19, C20, C21, C22, C25, diodes D5, D6, D7 and a transistor Q2, is powered by the second DC voltage signal, and is used to output a PWM control signal to control the half-bridge conversion circuit 21.

[0022] Example 4, based on Example 1, see Figure 6 The high-precision voltage stabilization circuit 30 includes a high-precision voltage stabilizer 31 and a voltage adjustment circuit 32, see Figure 7 The high-precision voltage regulator 31 is connected to the stable third DC voltage signal, and adopts the LT431 voltage reference chip U4, resistors R16, R17, R20, transistor Q5, and potentiometer RT2 to output stable positive voltage signal VC2+ and negative voltage signal VC2-. The voltage adjustment circuit 32 composed of R16, R20 and RT2 collects the positive voltage signal and the negative voltage signal, and feeds them back to the voltage reference chip for adjusting the voltage division and outputting DC positive and negative voltage signals.

Claims

1. An adjustable output isolation driving power supply circuit with a wide input voltage range, comprising a primary DC-DC conversion circuit (10), a secondary isolation DC-DC conversion circuit (20) and a high-precision voltage stabilization circuit (30), characterized in that: The first-level DC-DC conversion circuit (10) inputs a first voltage signal with a wide range, converts it into a stable second direct current voltage signal, and outputs it to the second-level isolated DC-DC conversion circuit (20); The secondary isolation DC-DC conversion circuit (20) converts the second DC voltage signal into a third DC voltage signal, and outputs the third DC voltage signal to a high-precision voltage stabilization circuit (30); The high-precision voltage stabilization circuit (30) outputs stable direct current positive voltage signals and negative voltage signals through high-precision voltage stabilization and voltage regulation.

2. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 1, characterized in that: The first-stage DC-DC conversion circuit (10) comprises a DC-DC control chip (12), an input filter circuit (11), an energy storage filter circuit (15), a feedback regulation circuit (13) and a frequency compensation circuit (14); The input filter circuit (11) receives a first voltage signal in a wide range and performs filtering, and after filtering, supplies power to the DC-DC control chip (12); The DC-DC control chip (12) inputs the filtered signal and outputs the required second DC voltage signal by adjusting the switch logic and duty cycle of the internal switch tube; The second DC voltage signal enters an energy storage filter circuit (15) to store energy and reduce the switching ripple of the output voltage, thereby outputting a stable second DC voltage signal; The feedback regulation circuit (13) collects a stable second DC voltage signal and feeds it back to the DC-DC control chip (12) to stabilize the second DC voltage signal; The frequency compensation circuit (14) is connected to the DC-DC control chip (12) and compensates for the internal operating frequency of the DC-DC control chip (14).

3. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 1, characterized in that: The secondary isolated DC-DC conversion circuit (20) comprises a PWM control circuit (22), a half-bridge conversion circuit (21), a high-frequency isolation transformer (23) and a rectifier filter circuit (24); The half-bridge conversion circuit (21) receives the stable second DC voltage signal, amplifies it and converts it into an AC voltage signal, the AC voltage signal is electrically isolated via a high-frequency isolation transformer (23), and finally rectified and filtered by a rectifier and filter circuit (24) to output a stable third DC voltage signal; The PWM control circuit (22) is powered by the second DC voltage signal and is used to output a PWM control signal to control the half-bridge conversion circuit (21).

4. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 1, characterized in that: The high-precision voltage stabilization circuit (30) comprises a high-precision voltage stabilizer (31) and a voltage adjustment circuit (32); the high-precision voltage stabilizer (31) is connected to the stable third DC voltage signal, and uses a voltage reference chip to stabilize and output a stable positive voltage signal and a negative voltage signal; the positive voltage signal and the negative voltage signal are collected by the voltage adjustment circuit (32) and fed back to the voltage reference chip.

5. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 4, characterized in that: The voltage reference chip is LT431.

6. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 3, characterized in that: The half-bridge conversion circuit (21) comprises a half-bridge topology structure composed of triodes and a half-bridge topology structure composed of MOS tubes.

7. The adjustable output isolation driving power supply circuit with wide input voltage range according to claim 3, characterized in that: The rectification and filtering circuit (24) comprises a voltage doubling rectification circuit and a filtering circuit.

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