Wide voltage input high performance boost circuit

Abstract

The application discloses a wide voltage input high-performance boost circuit, which comprises a battery, a voltage change module, a boost circuit module and a logic control module; the voltage is connected with the voltage change module; the voltage change module supplies power to the boost circuit module; the logic control module controls the boost circuit to boost through a PWM signal; the boost circuit is powered by a voltage control module and the logic control module provides a signal to generate a high-voltage output. The application converts the unstable voltage output of a hot battery into stable voltage through a voltage change module, and controls the output voltage value of the boost circuit through a logic control module, so that the demand of the boost circuit for stable output in the scene with large fluctuation of input voltage is met, and the technical problems of introducing high-order harmonics and limited working efficiency in the prior art are solved.

Description

Technical Field

[0001] This application relates to the field of electronic power technology, and in particular to a high-performance boost circuit with wide voltage input. Background Technology

[0002] Currently, high-voltage converter circuits generally use the flyback high-voltage conversion method to generate high voltage. See [link to relevant documentation]. Figure 1 This is a schematic diagram of a prior art flyback high-voltage converter circuit topology provided for an embodiment of this application. Figure 1 In the flyback high-voltage converter circuit, a control chip is used to control the operation of the transformer. For example, when the primary side of the transformer is energized, it operates in an inductive state, and the secondary coil does not output voltage; while when the primary side is turned off, it operates in a linear transformer state, and the secondary coil outputs high voltage. The advantage of this circuit is that it has fewer components, a simpler structure, and is easier to implement. However, this operating mode brings the following problems: (1) The high-voltage energy storage capacitor can only be charged when the primary side is turned off, which limits the working efficiency. In order to obtain a higher charging speed, the excitation current must be increased, which requires a high supply current of the battery. At the same time, in order to prevent the transformer core from saturating, the excitation time needs to be strictly controlled. Therefore, the excitation current of the primary side is a short, high-frequency pulse current, which causes a significant impact on the battery system and introduces obvious high-order harmonics.

[0003] (2) In the flyback high voltage converter circuit, the secondary coil of the transformer outputs pulse high voltage only when the primary side is turned off. There are many high-order harmonic components. Since the transformer is working in a linear state at this time, the primary side is coupled with the induced voltage according to the transformer turns ratio. As a result, the high-order harmonics are introduced into the primary side, causing pollution to the system battery.

[0004] (3) When the voltage of the high voltage energy storage capacitor is high, the primary side induced voltage will also reach a high amplitude, thereby causing a high reverse voltage on the primary side coil driving device, up to nearly 100 volts, which can easily cause the device to break down.

[0005] (4) In the flyback high voltage converter circuit, the magnetic flux of the transformer core changes abruptly when the primary side is turned off. The high cut-off speed will generate a high instantaneous reverse electromotive force in the source coil, with an amplitude of tens of volts.

[0006] Therefore, although the flyback high-voltage converter circuit in the prior art has the advantage of circuit simplicity, its operating mode brings significant instantaneous current and high-order harmonics, and the components are subjected to high electrical stress. These problems can be improved through comprehensive filtering and protection circuits, but in applications with limited battery capacity, compact circuit structure, and where complex auxiliary circuits cannot be added, it is prone to causing battery voltage fluctuations, exacerbating system electromagnetic interference, and damaging components. Summary of the Invention

[0007] The technical problem addressed by this application is the introduction of high-order harmonics, limited operating efficiency, and unstable voltage provided by the thermal battery in existing technologies. This application provides a wide-voltage input high-performance boost circuit. In the solution provided by this application's embodiments, as long as the battery voltage fluctuates within a certain range, regardless of whether the primary winding of the transformer is energized or turned off, the secondary winding of the transformer can generate an induced voltage, causing the transformer to adjust from a half-cycle pulse mode to a full-cycle quasi-sinusoidal operating mode. The full-cycle quasi-sinusoidal operating mode means that the induced voltage signal output by the transformer within one cycle of the PWM signal is an approximately sinusoidal signal. Because the output voltage signal of the secondary winding exhibits an approximately sinusoidal waveform, high-order harmonic components are significantly reduced.

[0008] On one hand, this application provides a wide voltage input high-performance boost circuit, characterized in that it includes: a battery, a voltage change module, a boost circuit module, and a logic control module; the battery is connected to the voltage change module; the voltage change module supplies power to the boost circuit module; the logic control module controls the boost circuit to boost voltage via a PWM signal; the boost circuit is powered by the voltage control module and generates a high-voltage output by the signal provided by the logic control module.

[0009] Optionally, the battery is supplied with a voltage of 18~36V; Optionally, the voltage changing module includes: a first terminal block, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a first voltage regulator chip; the first terminal block is connected to the battery and is used to receive the battery voltage output by the battery; the first end of the first terminal block is connected to the first capacitor, the second capacitor, and the first voltage regulator chip respectively; the second end of the first terminal block is connected to the first capacitor, the second capacitor, and the first voltage regulator chip respectively; the first ends of the third capacitor and the fourth capacitor are connected to the first voltage regulator chip; and the second ends of the third capacitor and the fourth capacitor are grounded.

[0010] Optionally, the first voltage regulator chip is a WRB2412S chip, used to convert an 18~36V input voltage into a 24V output voltage.

[0011] Optionally, the boost circuit module includes: a second terminal block, a transformer, a transistor, a MOSFET circuit, an absorption circuit, and an output circuit; wherein the second terminal block is connected to both ends of the primary winding of the transformer; the absorption circuit is connected in parallel with the primary winding; the transistor is connected in parallel with the battery, wherein the collector is connected to the positive terminal of the battery, the emitter is connected to the negative terminal of the battery, and the base is connected to an external control chip; the MOSFET circuit includes a MOSFET and a first diode and a fifth capacitor connected in parallel with the MOSFET, the drain of the MOSFET is connected to one end of the primary winding, the source is connected to the emitter of the transistor, and the gate is connected to the collector of the transistor; the output circuit is connected in parallel with the secondary winding of the transformer and is used to boost and output voltage based on the induced voltage of the secondary winding. Specifically, a pulse width modulation (PWM) signal is input to the transistor via an external control chip. When the PWM signal is high, the transistor is turned on and enters saturation, while the MOSFET is not turned on. The voltage at one end of the secondary coil increases, and a first induced voltage is output. When the PWM signal is low, the transistor is turned off, the MOSFET conducts and generates an excitation current, the transformer operates, and the secondary coil outputs a second induced voltage.

[0012] Optionally, the output circuit includes a second diode, a third diode, a sixth capacitor, and a seventh capacitor. The second diode is connected in parallel with the secondary winding of the transformer. The third diode is connected in series with the seventh capacitor and then in parallel with the second diode. One end of the sixth capacitor is connected to the secondary winding, and the other end is connected to the cathode of the second diode. When the PWM signal is high, the second diode is turned on, and current flows through the second diode to charge the sixth capacitor. When the PWM signal is low, the transistor is turned off, the MOSFET is turned on and generates a magnetizing current, the transformer is activated, the third diode is turned on, and current flows through the sixth capacitor and the third diode to charge the seventh capacitor.

[0013] Optionally, the absorption circuit includes an eighth capacitor and a resistor, wherein the eighth capacitor and the resistor are connected in series; wherein, when the PWM signal is high, the transistor is turned on and enters saturation, the MOSFET is not turned on, the primary coil has no excitation current, and the magnetic flux accumulated when it is turned on is absorbed by the absorption circuit.

[0014] Optionally, the transformer operates in a full-cycle quasi-sinusoidal operating mode, wherein the full-cycle quasi-sinusoidal operating mode means that the induced voltage signal output by the transformer within one cycle of the PWM signal is an approximately sinusoidal signal.

[0015] Optionally, the characteristic is that, within one cycle of the PWM signal, the voltage of the seventh capacitor after charging is the sum of the first induced voltage and the second induced voltage.

[0016] Optionally, the MOSFET is connected to the transistor, and the MOSFET is driven by the signal generated by the transistor being turned on, so that the MOSFET is driven in a low-speed driving mode.

[0017] Compared with the prior art, the solution provided in this application has at least the following beneficial effects: 1. In the solution provided in this application embodiment, regardless of whether the primary winding of the transformer is energized or turned off, the secondary winding of the transformer can generate an induced voltage, causing the transformer to adjust from a half-cycle pulse mode to a full-cycle quasi-sinusoidal operating mode. The full-cycle quasi-sinusoidal operating mode means that the induced voltage signal output by the transformer within one cycle of the PWM signal is an approximately sinusoidal signal. Because the output voltage signal of the secondary winding exhibits an approximately sinusoidal waveform, the high-order harmonic components are significantly reduced.

[0018] 2. In the solution provided in this application embodiment, when the voltage level is high, the sixth capacitor can be charged by the first induced voltage generated by the secondary coil. When the voltage level is low, the seventh capacitor can be charged simultaneously by the second induced voltage generated by the secondary coil and the sixth capacitor. That is, this circuit utilizes the rectification and guiding effect of the diode to store the induced voltages generated at high and low voltage levels onto their respective capacitors, and connects them in series according to the principle of polarity addition when the voltage level is low, so that the capacitance across the seventh capacitor becomes twice the voltage at the secondary end of the transformer after charging within one PWM signal cycle. In other words, the solution provided in this application embodiment uses a voltage doubling method to charge the seventh capacitor, which not only improves the charging efficiency but also reduces the working pressure and size of the transformer.

[0019] 3. In the solution provided in this application embodiment, a transistor is used to drive the MOSFET. By driving the MOSFET, the operating mode of the transformer is changed from pulse mode to quasi-sinusoidal mode. This makes the requirements for excitation time and current peak value more relaxed than those of pulse mode. Therefore, the MOSFET driving mode can be changed from traditional high-speed driving to low-speed driving. This can significantly reduce the peak current in the coil caused by the rapid conduction of the MOSFET. The change in driving mode also reduces the MOSFET turn-off speed. The rate at which the magnetic flux in the transformer core decreases is also slowed down. As a result, the back electromotive force generated when the primary coil is turned off will also be significantly reduced, further reducing the high-order harmonic pollution of the battery. Attached Figure Description

[0020] Figure 1 A schematic diagram of a prior art flyback high-voltage converter circuit topology provided for embodiments of this application; Figure 2 This is a schematic diagram of a wide voltage input high-performance boost circuit provided in an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the boost circuit module topology of a wide voltage input high-performance boost circuit provided in an embodiment of this application. Detailed Implementation

[0022] The embodiments described in this application are only a part of the embodiments, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0024] See Figure 2 This is a schematic diagram of a wide-voltage input high-performance boost circuit provided in an embodiment of this application. It includes: a battery, a voltage change module, a boost circuit module, and a logic control module; the battery is connected to the voltage change module; the voltage change module supplies power to the boost circuit module; the logic control module controls the boost circuit to increase voltage via a PWM signal; the boost circuit is powered by the voltage control module and generates a high-voltage output by signals provided by the logic control module.

[0025] See Figure 3 This is a schematic diagram of the topology of a wide-voltage input high-performance boost circuit provided in an embodiment of this application. Figure 3The boost circuit includes: a battery (V), a transformer (T), a transistor (QV1), a MOSFET circuit (QV2), an absorption circuit, and an output circuit. The positive and negative terminals of the battery are connected to the two ends of the primary winding of the transformer, respectively. The absorption circuit is connected in parallel with the primary winding. The transistor is connected in parallel with the battery, with its collector connected to the positive terminal, its emitter connected to the negative terminal, and its base connected to an external control chip. The MOSFET circuit includes a MOSFET and a first diode (D3) and a fifth capacitor (C4) connected in parallel with it. The drain of the MOSFET is connected to one end of the primary winding, its source is connected to the emitter of the transistor, and its gate is connected to the collector of the transistor. The output circuit is connected in parallel with the secondary winding of the transformer and is used to boost the voltage based on the induced voltage of the secondary winding and output the voltage. Specifically, a pulse width modulation (PWM) signal is input to the transistor via an external control chip. When the PWM signal is high, the transistor is turned on and enters saturation, while the MOSFET is not turned on. The voltage at one end of the secondary coil increases, and a first induced voltage is output. When the PWM signal is low, the transistor is turned off, the MOSFET conducts and generates an excitation current, the transformer operates, and the secondary coil outputs a second induced voltage.

[0026] In one possible implementation, the output circuit includes a second diode (D2), a third diode (D1), a sixth capacitor (C1), and a seventh capacitor (C2). The second diode is connected in parallel with the secondary winding of the transformer. The third diode is connected in series with the seventh capacitor and then in parallel with the second diode. One end of the sixth capacitor is connected to the secondary winding, and the other end is connected to the cathode of the second diode. When the PWM signal is high, the second diode is turned on, and current flows through the second diode to charge the sixth capacitor. When the PWM signal is low, the transistor is turned off, the MOSFET is turned on and generates a magnetizing current, the transformer operates, the third diode is turned on, and current flows through the sixth capacitor and the third diode to charge the seventh capacitor.

[0027] Specifically, in the solution provided in this application embodiment, the boost circuit uses a 24V battery voltage. The PWM signal is a periodic square wave signal, meaning that in one cycle of the PWM signal, half the cycle is high and the other half is low. The boost circuit boosts the voltage under the action of the PWM signal. For ease of understanding, the boost process of the boost circuit is briefly described below.

[0028] For example, the primary winding of the transformer has terminals 2 and 4, and the secondary winding has terminals 6 and 10. When a PWM signal is input to the transistor via an external control chip, the transistor conducts and enters saturation when at a high level, while the MOSFET connected to the transistor does not conduct. At this time, there is no magnetizing current on both sides (terminals 2 and 4) of the primary winding of the transformer. The residual magnetic flux accumulated when it is conducting is consumed by the absorption circuit, achieving demagnetization. At the same time, when the primary winding is energized, the voltage at terminal 6 of the secondary winding is higher than the voltage at terminal 10. When the primary winding is turned off (no magnetizing current), the secondary winding generates a reverse induced voltage, making the voltage at terminal 10 higher than the voltage at terminal 6. The potential at one end (terminal 10) of the secondary winding of the transformer becomes high, the second diode conducts, and the current flows through the second diode to charge the sixth capacitor. That is, the sixth capacitor is charged by the first induced voltage generated by the secondary winding at this time. Assume that the induced voltage of the secondary winding at this time is V. 10-6 Let the voltage across capacitor C1 be V. C1 Then V C1 = V 10-6 When the voltage is low, the transistor is off. At this time, the MOSFET's gate voltage is greater than its gate threshold voltage, causing the MOSFET to conduct and generate a magnetizing current. The transformer starts working, and terminals 2 of the transformer are at a relatively high potential, therefore terminal 6 is also at a high potential. The third diode conducts, and current flows through the sixth capacitor and the third diode to charge the seventh capacitor. That is, the seventh capacitor is charged simultaneously by the second induced voltage generated by the secondary coil and the energy stored in the sixth capacitor. At this time, the voltage of the seventh capacitor... for: Through charging over multiple PWM signal cycles, the sixth capacitor can be charged multiple times, eventually reaching its voltage at the first induced voltage V of the secondary coil. 10-6 When the voltage of the sixth capacitor reaches V 10-6 At that time, the second induced voltage V through the sixth capacitor and the secondary coil 10-6 When the seventh capacitor is charged, the voltage across the seventh capacitor is: This process is repeated until the voltage between the seventh capacitors is eventually brought up to the target voltage.

[0029] As can be seen from the above scheme, unlike existing technologies, within one PWM signal cycle, the primary coil of the transformer is energized, and the secondary coil is turned off. When the primary coil is turned off, the secondary coil generates an induced voltage. In the scheme provided by this application embodiment, regardless of whether the primary coil of the transformer is energized or turned off, the secondary coil of the transformer can generate an induced voltage, causing the transformer to adjust from a half-cycle pulse mode to a full-cycle quasi-sinusoidal operating mode. The full-cycle quasi-sinusoidal operating mode means that the induced voltage signal output by the transformer within one cycle of the PWM signal is an approximately sinusoidal signal. Because the output voltage signal of the secondary coil exhibits an approximately sinusoidal waveform, the high-order harmonic components are significantly reduced.

[0030] Furthermore, in the solution provided in this application embodiment, when the voltage level is high, the sixth capacitor can be charged through the first induced voltage generated by the secondary coil. When the voltage level is low, the seventh capacitor can be charged simultaneously through the second induced voltage generated by the secondary coil and the sixth capacitor. That is, this circuit utilizes the rectification and guiding effect of the diode to store the induced voltages generated at high and low voltage levels onto their respective capacitors, and connects them in series according to the principle of polarity addition when the voltage level is low, so that the capacitance across the seventh capacitor becomes twice the voltage at the secondary side of the transformer after charging within one PWM signal cycle. In other words, the solution provided in this application embodiment uses a voltage doubling method to charge the seventh capacitor, which not only improves charging efficiency but also reduces the operating pressure and size of the transformer.

[0031] Furthermore, in one possible implementation, the MOSFET is connected to the transistor, and the MOSFET is driven by the signal generated by the transistor being turned on, so that the MOSFET is driven in a low-speed driving mode.

[0032] In existing technologies, to achieve higher charging speeds, the excitation current must be increased, placing high demands on the battery's supply current. Simultaneously, to prevent transformer core saturation, the excitation time needs strict control. To meet the battery's supply current requirements within a limited time, a driver is typically used to directly drive the MOSFET. The signal generated by the driver is a pulse signal with a high amplitude and a very short duration. This means that existing technologies achieve high-speed driving of the MOSFET through a driver in a short time (i.e., high-speed pulse drive). In the solution provided in this application embodiment, a transistor is used to drive the MOSFET. By driving the MOSFET, the operating mode of the transformer is changed from pulse mode to quasi-sinusoidal mode. This makes the requirements for excitation time and current peak value more relaxed than those of pulse mode. Therefore, the MOSFET driving mode can be changed from traditional high-speed driving to low-speed driving. This can significantly reduce the peak current in the coil caused by the rapid conduction of the MOSFET. The change in driving mode also reduces the MOSFET turn-off speed. The rate at which the magnetic flux in the transformer core decreases is also slowed down. As a result, the back electromotive force generated when the primary coil is turned off will also be significantly reduced, further reducing the high-order harmonic pollution of the battery.

[0033] In one possible implementation, the absorption circuit includes an eighth capacitor (C3) and a resistor (R), wherein the eighth capacitor and the resistor are connected in series; wherein, when the PWM signal is high, the transistor is turned on and enters saturation, the MOSFET is not turned on, the primary coil has no excitation current, and the magnetic flux accumulated when it is turned on is absorbed by the absorption circuit.

[0034] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A wide-voltage input high-performance boost circuit, characterized in that, include: Battery, voltage change module, boost circuit module, logic control module; The battery is connected to the voltage change module; The voltage change module supplies power to the boost circuit module; The logic control module controls the boost circuit to boost voltage via a PWM signal; The boost circuit is powered by the voltage change module and the logic control module provides signals to generate a high voltage output. The voltage change module includes: a first terminal block, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a first voltage regulator chip; The first terminal is connected to the battery and is used to receive the battery voltage output by the battery; The first end of the first terminal is connected to the first capacitor, the second capacitor, and the first voltage regulator chip, respectively. The second end of the first terminal is connected to the first capacitor, the second capacitor, and the first voltage regulator chip, respectively. The first terminals of the third capacitor and the fourth capacitor are connected to the first voltage regulator chip. The second terminals of the third and fourth capacitors are grounded. The boost circuit module includes: a second terminal block, a transformer, a transistor, a MOSFET circuit, an absorption circuit, and an output circuit; wherein, the second terminal block is connected to both ends of the primary winding of the transformer; the absorption circuit is connected in parallel with the primary winding; the transistor is connected in parallel with the battery, wherein the collector is connected to the positive terminal of the battery, the emitter is connected to the negative terminal of the battery, and the base is connected to an external control chip; the MOSFET circuit includes a MOSFET and a first diode and a fifth capacitor connected in parallel with the MOSFET, the drain of the MOSFET is connected to one end of the primary winding, the source is connected to the emitter of the transistor, and the gate is connected to the collector of the transistor; the output circuit is connected in parallel with the secondary winding of the transformer and is used to boost the voltage based on the induced voltage of the secondary winding and output it; Specifically, a pulse width modulation (PWM) signal is input to the transistor via an external control chip. When the PWM signal is high, the transistor is turned on and enters saturation, while the MOSFET is not turned on. The voltage at one end of the secondary coil increases, and a first induced voltage is output. When the PWM signal is low, the transistor is turned off, the MOSFET is turned on and generates an excitation current, the transformer operates, and the secondary coil outputs a second induced voltage.

2. The wide voltage input high-performance boost circuit according to claim 1, characterized in that, The battery is supplied with a voltage of 18~36V.

3. The wide voltage input high-performance boost circuit according to claim 1, characterized in that, The first voltage regulator chip is a WRB2412S chip, which is used to convert an 18~36V input voltage into a 24V output voltage.

4. The wide voltage input high-performance boost circuit as described in claim 1, characterized in that, The output circuit includes a second diode, a third diode, a sixth capacitor, and a seventh capacitor. The second diode is connected in parallel with the secondary winding of the transformer. The third diode and the seventh capacitor are connected in series and then in parallel with the second diode. One end of the sixth capacitor is connected to the secondary winding, and the other end is connected to the cathode of the second diode. When the PWM signal is high, the second diode is turned on, and current flows through the second diode to charge the sixth capacitor. When the PWM signal is low, the transistor is turned off, the MOSFET is turned on and generates a magnetizing current, the transformer operates, the third diode is turned on, and current flows through the sixth capacitor and the third diode to charge the seventh capacitor.

5. The wide voltage input high-performance boost circuit as described in claim 4, characterized in that, The absorption circuit includes an eighth capacitor and a resistor, wherein the eighth capacitor and the resistor are connected in series; wherein, when the PWM signal is high, the transistor is turned on and enters saturation, the MOSFET is not turned on, the primary coil has no excitation current, and the magnetic flux accumulated when it is turned on is absorbed by the absorption circuit.

6. The wide voltage input high-performance boost circuit as described in claim 5, characterized in that, The transformer operates in a full-cycle quasi-sinusoidal operating mode, wherein the full-cycle quasi-sinusoidal operating mode means that the induced voltage signal output by the transformer within one cycle of the PWM signal is an approximately sinusoidal signal.

7. The wide voltage input high-performance boost circuit as described in claim 6, characterized in that, Within one cycle of the PWM signal, the voltage of the seventh capacitor after charging is the sum of the first induced voltage and the second induced voltage.

8. The wide voltage input high-performance boost circuit as described in any one of claims 1-7, characterized in that, The MOSFET is connected to the transistor, and the MOSFET is driven by the signal generated by the conduction of the transistor, so that the MOSFET is driven in a low-speed driving mode.

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