A high-power non-isolated boost-buck DC converter

Abstract

The utility model discloses a kind of high-power non-isolated type boost-buck DC converters, including the input filter module, power switch module, energy storage module, output filter module, drive control module connected in turn and respectively with drive control module connection's overcurrent protection module, overvoltage protection module, overheat protection module, the utility model, the low impedance direct current power transmission circuit of integrated transmission circuit, reduce the conduction loss of main power loop, signal synchronous transmission is simultaneously realized, reduce the parasitic loss of additional signal line.

Description

Technical Field

[0001] This utility model relates to the field of power electronic conversion technology, and in particular to a high-power non-isolated buck-boost DC converter. Background Technology

[0002] In scenarios such as new energy power supply and high-power industrial equipment, high-power non-isolated buck-boost DC converters need to meet the requirements of wide voltage input, output and efficient and stable power supply.

[0003] However, existing technologies suffer from several drawbacks. The main power circuit often uses ordinary wires, failing to consider the coordinated transmission of power and signals. The additional signal lines increase parasitic losses, and the main circuit conduction loss is high, making it difficult to improve converter efficiency. The drive signal transmission lacks a dedicated impedance matching structure, which easily leads to waveform reflection distortion. Furthermore, it lacks gate clamp protection, resulting in disordered on / off timing of power switches or susceptibility to overvoltage breakdown. The output filter often uses a single capacitor, which cannot simultaneously suppress high and low frequency ripple, resulting in high output ripple voltage and difficulty in adapting to precision loads. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as the use of ordinary wires in the circuits, which do not take into account the coordinated transmission of power and signals, resulting in increased parasitic losses due to additional signal lines and high conduction losses in the main circuit, making it difficult to improve converter efficiency; the lack of a dedicated impedance matching structure for drive signal transmission, which easily leads to waveform reflection distortion, and the lack of gate clamp protection, resulting in disordered on / off timing of power switches or easy overvoltage breakdown; and the use of a single capacitor for output filtering, which cannot simultaneously suppress high and low frequency ripple, resulting in high output ripple voltage and difficulty in adapting to precision loads. Therefore, this invention proposes a high-power non-isolated buck-boost DC converter.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high-power non-isolated buck-boost DC converter includes: an input filter module, a power switch module, an energy storage module, an output filter module, and a drive control module connected in sequence, as well as an overcurrent protection module, an overvoltage protection module, and an overheat protection module respectively connected to the drive control module; The input filtering module is connected to the energy storage module and the power switch module through a low-impedance DC power transmission circuit with integrated transmission circuitry to achieve low-loss transmission of power and signal. The power switch module and the drive control module are connected through a drive signal transmission circuit containing an impedance circuit to ensure impedance matching and effective transmission of the drive signal. The power switch module and the output filter module are connected through a DC power output circuit with a built-in capacitor filter circuit to achieve power transmission and ripple filtering. The overcurrent protection module is connected to the main circuit through a Hall current sensor sampling circuit, the overvoltage protection module is connected to the output filter module through a resistor voltage divider sampling circuit, and the overheat protection module is connected to the power switch module through a temperature sensing circuit processed by a signal conditioning circuit.

[0006] As a preferred embodiment of the high-power non-isolated buck-boost DC converter of this utility model, the transmission circuit is used for the transmission of analog and digital signals, including a transistor, a coupling capacitor and a current-limiting resistor. The analog input is connected to the base of the transistor through the coupling capacitor and the current-limiting resistor, the digital input is connected to the base of the transistor through the current-limiting resistor, the +6V power supply is connected to the base of the transistor through the bias resistor, the collector of the transistor is connected to a high potential through the pull-up resistor and the emitter is grounded, and the collector of the transistor serves as the signal output terminal to be transmitted to the subsequent modules.

[0007] As a preferred embodiment of the high-power non-isolated buck-boost DC converter of this utility model, the impedance circuit is used for impedance matching of the drive signal and includes an operational amplifier, a clamping diode and a matching resistor. The input signal terminal is connected in parallel with a clamping circuit composed of two inverting diodes and then connected to the non-inverting input terminal of the operational amplifier. The inverting input terminal and the output terminal of the operational amplifier are shorted to form a voltage follower, thereby achieving low output impedance and impedance matching with the input signal.

[0008] As a preferred embodiment of the high-power non-isolated buck-boost DC converter of this utility model, the capacitor filter circuit includes an output filter capacitor composed of a low-ESR polymer capacitor and a high-frequency ceramic capacitor connected in parallel. The positive terminal of the output filter capacitor is connected to the output terminal of the synchronous freewheeling switch in the power switching module, and the negative terminal is connected to the negative terminal of the input circuit. The high-frequency ripple of the output voltage is filtered out through the charging and discharging of the capacitor.

[0009] As a preferred embodiment of the high-power non-isolated step-up / step-down DC converter of this utility model, the Hall current sensor sampling circuit includes a Hall sensor and an operational amplifier conditioning circuit. The main circuit wire under test passes through the Hall sensor core. The voltage signal output by the Hall sensor is amplified and filtered by the operational amplifier conditioning circuit and then transmitted to the overcurrent protection module to realize isolated sampling and detection of the main circuit current.

[0010] As a preferred embodiment of the high-power non-isolated buck-boost DC converter of this utility model, the resistor divider voltage sampling circuit includes a voltage divider network consisting of a first voltage divider resistor and a second voltage divider resistor connected in series. The voltage divider network is connected in parallel across the output filter capacitor of the output filter module. The sampling voltage output at the voltage divider point is amplified and corrected by a signal conditioning circuit including an operational amplifier and a filter circuit, and then transmitted to the overvoltage protection module to ensure the accuracy and anti-interference capability of the sampling voltage.

[0011] Compared with the prior art, the beneficial effects of this utility model are: The low-impedance DC power transmission circuit with integrated transmission circuitry reduces the conduction loss of the main power circuit and simultaneously achieves synchronous signal transmission, reducing parasitic losses in additional signal lines.

[0012] Meanwhile, the drive signal transmission circuit with impedance circuitry, through voltage follower and clamping design, ensures that the drive signal is free from distortion and overvoltage, and the timing error of the power switch is small, avoiding damage to the switch; the filter circuit with low ESR polymer capacitor and high frequency ceramic capacitor in parallel can simultaneously filter out low frequency and high frequency ripple, meeting the power supply requirements of precision loads. Attached Figure Description

[0013] Figure 1 This invention provides a transmission circuit diagram for a high-power non-isolated buck-boost DC converter. Figure 2 The impedance circuit diagram of a high-power non-isolated step-up / step-down DC converter proposed in this utility model is shown below. Figure 3 This invention presents a capacitor filter circuit diagram for a high-power non-isolated buck-boost DC converter. Figure 4 This invention presents a Hall current sensor sampling circuit diagram for a high-power non-isolated buck-boost DC converter. Figure 5 This invention presents a resistor divider voltage sampling circuit diagram for a high-power non-isolated step-up / step-down DC converter. Figure 6 This invention presents a signal conditioning circuit diagram for a high-power non-isolated buck-boost DC converter. Detailed Implementation

[0014] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0015] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0016] Reference Figures 1-6A high-power non-isolated buck-boost DC converter comprises, in sequence, an input filter module, a power switch module, an energy storage module, an output filter module, a drive control module, and an overcurrent protection module, an overvoltage protection module, and an overheat protection module, which are respectively connected to the drive control module.

[0017] The input filtering module is connected to the energy storage module and the power switch module through a low-impedance DC power transmission circuit with integrated transmission circuitry to achieve low-loss transmission of power and signals. The transmission circuit is used for the transmission of analog and digital signals and includes transistors, coupling capacitors and current-limiting resistors. The analog input is connected to the base of the transistor through the coupling capacitor and the current-limiting resistor, and the digital input is connected to the base of the transistor through the current-limiting resistor. The +6V power supply is connected to the base of the transistor through the bias resistor. The collector of the transistor is connected to a high potential through the pull-up resistor and the emitter is grounded. The collector of the transistor serves as the signal output terminal to transmit signals to subsequent modules.

[0018] The power switch module and the drive control module are connected through a drive signal transmission circuit containing an impedance circuit to ensure impedance matching and effective transmission of the drive signal. The impedance circuit is used for impedance matching of the drive signal and includes an operational amplifier, clamping diodes, and matching resistors. The input signal terminal is connected in parallel with a clamping circuit composed of two inverting diodes, which is then connected to the non-inverting input terminal of the operational amplifier. The inverting input terminal and the output terminal of the operational amplifier are shorted to form a voltage follower, thereby achieving low output impedance and impedance matching with the input signal.

[0019] The power switch module and the output filter module are connected through a DC power output circuit with a built-in capacitor filter circuit to achieve power transmission and ripple filtering. The capacitor filter circuit includes an output filter capacitor composed of a low ESR polymer capacitor and a high-frequency ceramic capacitor connected in parallel. The positive terminal of the output filter capacitor is connected to the output terminal of the synchronous freewheeling switch in the power switch module, and the negative terminal is connected to the negative terminal of the input circuit. The high-frequency ripple of the output voltage is filtered out through the charging and discharging of the capacitor.

[0020] The overcurrent protection module is connected to the main circuit through the Hall current sensor sampling circuit, and the overvoltage protection module is connected to the output filter module through the resistor voltage divider sampling circuit. The Hall current sensor sampling circuit includes a Hall sensor and an operational amplifier conditioning circuit. The main circuit wire under test passes through the Hall sensor core. The voltage signal output by the Hall sensor is amplified and filtered by the operational amplifier conditioning circuit and then transmitted to the overcurrent protection module to realize the isolated sampling and detection of the main circuit current.

[0021] The resistor divider voltage sampling circuit includes a voltage divider network consisting of a first voltage divider resistor and a second voltage divider resistor connected in series. The voltage divider network is connected in parallel across the output filter capacitor of the output filter module. The sampled voltage output at the voltage divider point is amplified and corrected by a signal conditioning circuit containing an operational amplifier and a filter circuit before being transmitted to the overvoltage protection module to ensure the accuracy and anti-interference capability of the sampled voltage.

[0022] The overheat protection module is connected to the power switch module through a temperature sensing circuit processed by a signal conditioning circuit. An NTC thermistor (such as MF52-10kΩ, with a resistance of 10kΩ at 25℃) is placed close to the MOSFET case of the power switch module. The temperature and resistance change signals output by the thermistor are converted into voltage signals (such as 1.5V output at 85℃) by the signal conditioning circuit and then transmitted to the overheat protection module. The signal conditioning circuit can compensate for the nonlinear error of the NTC and improve the temperature detection accuracy.

[0023] The input voltage is filtered by the input filter module and then split into two paths: one to the energy storage inductor and the other to the source of the main MOSFET. The drive control module outputs a PWM signal to control the main MOSFET to turn on, so that the energy storage inductor stores energy. When the main MOSFET is turned off and the synchronous freewheeling MOSFET is turned on, the energy storage inductor releases energy and outputs a stable voltage to the load after being filtered by the output filter module. When the main circuit current reaches 60A (overcurrent threshold), the Hall sensor outputs a 3V signal, which is amplified to 5V by the LM358 and transmitted to the overcurrent protection module. The protection module outputs a low level to the drive control module, and the drive module immediately shuts off the PWM signal. When the output voltage exceeds 52.8V or the MOSFET temperature exceeds 100℃, the corresponding protection module is triggered to realize the converter shutdown protection.

[0024] It is worth noting that the entire device is controlled by a controller. Since the controller is a common device and belongs to existing mature technology, its electrical connection relationship and specific circuit structure will not be described in detail here.

[0025] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model. In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A high-power non-isolated buck-boost DC converter, comprising: The input filtering module, power switch module, energy storage module, output filtering module, drive control module, and overcurrent protection module, overvoltage protection module, and overheat protection module connected in sequence to the drive control module are characterized in that: The input filtering module is connected to the energy storage module and the power switch module through a low-impedance DC power transmission circuit with integrated transmission circuitry to achieve low-loss transmission of power and signal. The power switch module and the drive control module are connected through a drive signal transmission circuit containing an impedance circuit to ensure impedance matching and effective transmission of the drive signal. The power switch module and the output filter module are connected through a DC power output circuit with a built-in capacitor filter circuit to achieve power transmission and ripple filtering. The overcurrent protection module is connected to the main circuit through a Hall current sensor sampling circuit, the overvoltage protection module is connected to the output filter module through a resistor voltage divider sampling circuit, and the overheat protection module is connected to the power switch module through a temperature sensing circuit processed by a signal conditioning circuit.

2. The high-power non-isolated buck-boost DC converter according to claim 1, characterized in that: The transmission circuit is used for the transmission of analog and digital signals. It includes a transistor, a coupling capacitor, and a current-limiting resistor. The analog input is connected to the base of the transistor via the coupling capacitor and the current-limiting resistor. The digital input is connected to the base of the transistor via the current-limiting resistor. The +6V power supply is connected to the base of the transistor via a bias resistor. The collector of the transistor is connected to a high potential via a pull-up resistor, and the emitter is grounded. The collector of the transistor serves as the signal output terminal for transmission to subsequent modules.

3. The high-power non-isolated buck-boost DC converter according to claim 1, characterized in that: The impedance circuit is used for impedance matching of the drive signal. It includes an operational amplifier, clamping diodes and matching resistors. The input signal terminal is connected in parallel with a clamping circuit composed of two inverting diodes and then connected to the non-inverting input terminal of the operational amplifier. The inverting input terminal and the output terminal of the operational amplifier are shorted to form a voltage follower, thereby achieving low output impedance and impedance matching with the input signal.

4. The high-power non-isolated buck-boost DC converter according to claim 1, characterized in that: The capacitor filter circuit includes an output filter capacitor composed of a low-ESR polymer capacitor and a high-frequency ceramic capacitor connected in parallel. The positive terminal of the output filter capacitor is connected to the output terminal of the synchronous freewheeling switch in the power switching module, and the negative terminal is connected to the negative terminal of the input circuit. The high-frequency ripple of the output voltage is filtered out through the charging and discharging of the capacitor.

5. The high-power non-isolated buck-boost DC converter according to claim 1, characterized in that: The Hall current sensor sampling circuit includes a Hall sensor and an operational amplifier conditioning circuit. The main circuit wire being measured passes through the Hall sensor core. The voltage signal output by the Hall sensor is amplified and filtered by the operational amplifier conditioning circuit before being transmitted to the overcurrent protection module to achieve isolated sampling and detection of the main circuit current.

6. The high-power non-isolated buck-boost DC converter according to claim 1, characterized in that: The resistor-divider voltage sampling circuit includes a voltage divider network consisting of a first voltage divider resistor and a second voltage divider resistor connected in series. The voltage divider network is connected in parallel across the output filter capacitor of the output filter module. The sampling voltage output at the voltage divider point is amplified and corrected by a signal conditioning circuit containing an operational amplifier and a filter circuit before being transmitted to the overvoltage protection module to ensure the accuracy and anti-interference capability of the sampling voltage.

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