System gain adjustment and wide output voltage power supply device

Abstract

A system gain adjustment and wide output voltage power supply device includes an inverter circuit module, a resonant circuit module connected to the inverter circuit module, a 4x rectifier circuit module connected to the resonant circuit module, a signal logic circuit module connected to the inverter circuit module, and a switching module connected to the resonant circuit module. The resonant circuit module includes an upper resonant circuit, an upper transformer connected to the upper resonant circuit, a lower resonant circuit connected to the upper resonant circuit, and a lower transformer connected to the lower resonant circuit for outputting an output voltage. The switching module, using a switching diode, rectifies the output voltage in conjunction with the 4x rectifier circuit module to output an operating voltage according to the mode with better power switching efficiency.

Description

Technical Field

[0001] This invention relates to a power converter, and more particularly to a system gain adjustment and wide output voltage power supply device. Prior Technology

[0002] LLC resonant converters are a common type of isolated power converter. In addition to their simple structure and advantages of high efficiency and high power density over a wide load range, they can also achieve zero-voltage switching (ZVS) of MOSFETs and zero-current switching (ZCS) of diodes. As a result, they are widely used in rapidly developing electric vehicles in recent years to minimize losses and improve efficiency when electric vehicles perform necessary power switching during driving.

[0003] However, when the switching frequency of an LLC resonant converter is higher than the resonant frequency, the rectifier diodes within it cannot achieve zero-current switching. Furthermore, the relatively flat voltage gain curve in this frequency range makes output voltage regulation difficult. Therefore, LLC resonant converters are typically designed to operate within a switching frequency range less than or equal to the resonant frequency to achieve zero-voltage switching, zero-current switching, and good output voltage regulation. Additionally, when the operating frequency deviates significantly from the resonant frequency, the increased circulating current in the resonant circuit greatly reduces conversion efficiency. This necessitates a balance between conversion efficiency and operating range for the LLC resonant converter to meet requirements. Directly adjusting the voltage via frequency modulation in an LLC resonant converter will cause the failure of one of the flexible switching characteristics of zero-voltage switching and zero-current switching, thus increasing losses and reducing efficiency. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide a system gain adjustment and wide output voltage power supply device that can maintain flexible switching characteristics while providing a wide output voltage range.

[0005] Therefore, the system gain adjustment and wide output voltage power supply device of the present invention includes an inverter circuit module suitable for connecting to a power supply for providing an input voltage, a resonant circuit module connected downstream of the inverter circuit module, a quadrupole rectifier circuit module connected downstream of the resonant circuit module for rectifying the output voltage to output an operating voltage, a signal logic circuit module connected to the inverter circuit module, and a switching module connected to the resonant circuit module.

[0006] The inverter circuit module includes a leading arm and a lagging arm.

[0007] The resonant circuit module includes an upper resonant circuit, an upper transformer connected to the upper resonant circuit, a lower resonant circuit connected to the upper resonant circuit, and a lower transformer connected to the lower resonant circuit for transforming the input voltage together with the upper transformer to output an output voltage.

[0008] The signal logic circuit module is used to provide two control signals to the leading arm and the lagging arm respectively. These control signals are used to control the operating frequency, working cycle, and phase shift of the leading arm and the lagging arm respectively.

[0009] The switching module includes a parallel resonant circuit connected in parallel with the upper resonant circuit, and two switching diodes connected to the parallel resonant circuit. The switching diodes are used to switch the switching module between a non-conducting state and a parallel resonant state that turns on the parallel resonant circuit.

[0010] The advantages of this invention are as follows: the control signals generated by the signal logic circuit module can effectively control the phase shift between the leading arm and the lagging arm of the inverter circuit module, allowing the power signal waveform to be completely superimposed before and after voltage switching. This maintains flexible switching characteristics while providing a wide output voltage range, achieving the effects of reducing power loss and improving operating efficiency. Furthermore, the switching module can switch to the non-conducting state of directly using the resonant circuit module, and the parallel resonant state of connecting the parallel resonant circuit and the resonant circuit module in parallel, based on the critical values ​​of heavy and light power loads. Therefore, regardless of whether the power range is above or below the critical value, it can adopt a better-performing state to optimize overall efficiency. Simple Explanation of the Diagram

[0011] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: Figure 1 is a block diagram illustrating one embodiment of the system gain adjustment and wide output voltage power supply device of the present invention; Figure 2 is a circuit diagram, which is used in conjunction with Figure 1 to illustrate this embodiment; Figure 3 (including Figures 3a and 3b) is a schematic diagram illustrating that this embodiment provides an isolation circuit module for one of the pulse width modulation signals; Figures 4a to 4d are circuit diagrams illustrating various operating states of this embodiment; Figures 5 through 8 are waveform diagrams. Figures 4a through 4d illustrate the key waveforms at 250V and 800V in this embodiment. Figures 9 and 10 are both waveform diagrams, illustrating the operation of this embodiment under a single voltage gain. Figures 11 to 14 are waveform diagrams illustrating the simulation results of this embodiment; and Figure 15 is a line graph illustrating the efficiency of this embodiment compared to bridge rectification and multiresonance. Implementation

[0012] Referring to Figures 1 and 2, an embodiment of the system gain adjustment and wide output voltage power supply device of the present invention is shown. This embodiment includes an inverter circuit module 2 suitable for connecting to a power supply 1 for providing an input voltage, a resonant circuit module 3 connected downstream of the inverter circuit module 2, a quadrupole rectifier circuit module 4 connected downstream of the resonant circuit module 3 for rectifying the output voltage to output a working voltage, a switching module 5 connected to the resonant circuit module 3, a signal logic circuit module 6 connected to the inverter circuit module 2, and an isolation circuit module 7 connected between the signal logic circuit module 6 and the inverter circuit module 2.

[0013] Referring to Figure 3, this drive signal circuit uses the Texas Instruments IC UC3879 to generate control drive signals. To prevent signal interference, as shown in Figure 3a, the Broadcom IC HCPL-3120 is used for signal isolation. Its internal pinout and usage are shown in Figures 3a and 3b. This prevents signal interference during converter power-up, which could lead to short circuits and circuit damage. The isolation circuit module 7 consists of four optocouplers 71, four resistors 72, and two diodes 73. That is, a drive isolator for a half-bridge converter is formed by two optocouplers 71, one diode 73, and a capacitor, creating a boost charge pump to form a bootstrap circuit.

[0014] Referring again to Figures 1 and 2, the inverter circuit module 2 includes a leading arm 21 and a lagging arm 22. The leading arm 21 has two first power switching switches 211, and the lagging arm 22 has two second power switching switches 221. The leading arm 21 is activated by the positive edge of an effective pulse width modulation (PWM) signal, and the lagging arm 22 is activated by the positive edge of an PWM signal whose phase shift lags behind that of the leading arm 21. Furthermore, each of the first power switching switches 211 and each of the second power switching switches 221 has a built-in body diode and parasitic capacitance.

[0015] The resonant circuit module 3 includes an upper resonant circuit 31, an upper transformer 32 connected to the upper resonant circuit 31, a lower resonant circuit 33 connected to the upper resonant circuit 31, and a lower transformer 34 connected to the lower resonant circuit 33 and used together with the upper transformer 32 to transform the input voltage to output an output voltage. Specifically, the resonant circuit module 3 is composed of two half-bridge LLC circuits.

[0016] The upper resonant circuit 31 has an upper first inductor 311, an upper capacitor 312 connected in series with the upper first inductor 311, and an upper magnetizing inductor 313 contained in the upper transformer 32 itself; the lower resonant circuit 33 has a lower first inductor 331, a lower capacitor 332 connected in series with the lower first inductor 331, and a lower magnetizing inductor 333 contained in the lower transformer 34 itself. Furthermore, the upper transformer 32 has an upper primary side 321 and an upper secondary side 322, while the lower transformer 34 has a lower primary side 341 and a lower secondary side 342. The upper primary side 321 of the upper transformer 32 is connected in parallel with the lower primary side 341 of the lower transformer 34, and the upper secondary side 322 of the upper transformer 32 is connected in series with the lower secondary side 342 of the lower transformer 34.

[0017] The quadruple voltage multiplier rectifier circuit module 4 includes four rectifier diodes 41, four rectifier voltage multiplier capacitors 42, and an output filter capacitor 43 connected in parallel with the rectifier voltage multiplier capacitors 42. The quadruple voltage multiplier rectifier circuit module 4 can switch between operating states of the five capacitors connected to different numbers of the rectifier voltage multiplier capacitors 42.

[0018] The signal logic circuit module 6 is pre-programmed with logic to provide two control signals to the leading arm 21 and the lagging arm 22, respectively. These control signals are used to control the operating frequency, duty cycle, and phase shift of the leading arm 21 and the lagging arm 22, respectively. Specifically, regarding the phase shift of the leading arm 21 and the lagging arm 22, the signal logic circuit module 6 includes an adjustment circuit for receiving a reference voltage set according to the voltage level VO and adjusting the phase shift between the leading arm 21 and the lagging arm 22 accordingly. Additionally, the signal logic circuit module 6 is also used to adjust the lag time of the signal between any of the first power switching switches 211 and any of the second power switching switches 221. In this embodiment, to facilitate intuitive setting of the reference voltage according to load requirements, the reference voltage is proportionally shifted to the voltage level VO.

[0019] Referring to Figure 3, this illustrates the operating mode of the isolation circuit module 7. When the low-side drive switch in the forearm switch... On and high-side drive switch Cut off, and power supply For capacitors , Charging, however, power supply via diode (63) Conduction, for capacitor , Charging to provide high-end drive switches in advanced forearm switches Required voltage. When the high-side drive switch in the forearm switch... When the circuit is turned on, the low-side drive switch is activated. Cut-off. There is a lag time between the high-side and low-side drive switching signals in the advanced arm 21 to avoid switching... With switch Simultaneous conduction caused the lead arm switch to short-circuit and burn out. Additionally, when the low-side drive switch in the lagging arm switch... On and high-side drive switch Deadline, at the same time Power supply to capacitor , Charging, however Power is supplied through a diode (63) Conduction, for capacitor , Charging to provide high-end drive switches in hysteresis arm switches Required voltage. When the high-side drive switch in the hysteresis arm switch... When the circuit is turned on, the low-side drive switch is activated. Cut-off. There is a lag time between the high-side and low-side drive switching signals in the hysteresis arm 22 to prevent switching... With switch Simultaneous conduction caused the delay arm switch to short-circuit and burn out.

[0020] Referring to Figures 4 to 8 and in conjunction with Figure 2, and in conjunction with the control signals provided by the signal logic circuit module 6 to the inverter circuit module 2, the resonant circuit module 3 in this embodiment, when working with the quadruple rectifier circuit module 4, will be divided into multiple operating states, each connected to a different number of rectifier voltage multiplier capacitors 42. The operating mode of the first half-cycle will be described first; the second half-cycle is generally symmetrical.

[0021] Referring to Figure 4a, which shows the first operating state [t0, t1], and referring to Figures 5 to 8, Figures 5 and 7 show the waveform for an output voltage of 250 volts, while Figures 6 and 8 show the waveform for an output voltage of 800 volts. This turns on one of the second power switching switches 221 in the lag arm 22, while the other second power switching switch 221 and the first power switching switches 211 are all off. The quadrupole rectifier circuit module 4 connects two rectifier voltage multiplier capacitors 42 and the output filter capacitor 43, as well as a rectifier diode 41. At this time, the first power switching switches 211 in the leading arm 21 are in a lag period. In conjunction with the upper first inductor 311 of the upper resonant circuit 31 of the resonant circuit module 3, the parasitic capacitances of the first power switching switches 211 release and store energy respectively.

[0022] Referring to Figure 4b, this represents operating state two [t1, t2]: Following operating state one, as shown in Figures 5 to 8, the first power switching switch 211 corresponding to the upper resonant circuit 31 is turned on. At this time, the corresponding parasitic capacitor has released energy, allowing the turned-on first power switching switch 211 to complete zero-voltage switching. The quadruple rectifier circuit module 4 connects the aforementioned rectifier voltage multiplier capacitor 42, the output filter capacitor 43, and the rectifier diode 41. At this time, the current in the upper first inductor 311 of the upper resonant circuit 31 and the upper magnetizing inductor 313 of the upper transformer 32 continuously increases, while the current in the lower resonant circuit 33 decreases. The resulting current difference allows energy to be transferred to the lower resonant circuit 33.

[0023] Referring to Figure 4c, this represents operating state three [t2, t3]: Following operating state two, as shown in Figures 5 to 8, the second power switching switch 221 corresponding to the lower resonant circuit 33 is turned off, causing the second power switching switches 221 in the lag arm 22 to be in a lag period. The quadruple rectifier circuit module 4 connects the four rectifier multiplier capacitors 42 to the output filter capacitor 43, and two rectifier diodes 41. At this time, the second power switching switches 221, in conjunction with the lower first inductor 331 of the lower resonant circuit 33, allow the parasitic capacitances of the second power switching switches 221 to release and store energy, respectively. At this time, the lower resonant circuit 33 will still transmit current to the lower resonant circuit 33 due to the current difference with the upper resonant circuit 31, and in conjunction with the conduction of some of the rectifier diodes 41, it will clamp the upper excitation inductance 313 of the upper transformer 32 of the upper resonant circuit 31.

[0024] Referring to Figure 4d, which represents operating state four [t3, t4]: In conjunction with Figures 5 to 8, the second power switching switch 221 corresponding to the upper resonant circuit 31 is further turned on. At this time, the corresponding parasitic capacitor has completed energy release, thus enabling conduction while achieving zero-voltage switching. The quadruple rectifier circuit module 4 connects the three aforementioned rectifier multiplier capacitors 42 to the output filter capacitor 43, and one rectifier diode 41. Energy is still transferred to the lower resonant circuit 33 through the current difference between the upper resonant circuit 31 and the lower resonant circuit 33. With appropriate idling time, the rectifier diode 41 corresponding to the lower resonant circuit 33 provides load energy after conduction, which, combined with the aforementioned energy release of the parasitic capacitor, effectively achieves the effect of zero-voltage switching. Next, since the upper magnetizing inductance 313 of the upper transformer 32 in the upper resonant circuit 31 and the lower magnetizing inductance 333 of the lower transformer 34 in the lower resonant circuit 33 are clamped by the output voltage and do not participate in resonance, the current difference between the upper resonant circuit 31 and the lower resonant circuit 33 gradually disappears. At this time, the current of part of the rectifier diode 41 also drops to zero, thus achieving the condition of zero current switching.

[0025] In operating state 5 [t4, t5]: Referring to Figures 5 to 8, both the first power switching switch 211 and the second power switching switch 221 corresponding to the upper resonant circuit 31 are turned on. Since energy is no longer supplied to the lower resonant circuit 33, the lower transformer 34 transfers energy through the current difference between the lower first inductor 331 and the lower magnetizing inductor 333. The quadrupole rectifier circuit module 4 is only connected to the output filter capacitor 43. At this time, the upper transformer 32 does not provide energy, therefore the upper first inductor 311, the upper magnetizing inductor 313, and the upper capacitor 312 resonate, and all rectifier diodes 41 are turned off. Therefore, when the lower transformer 34 is only supplied with load energy by the output filter capacitor 43, the current in the rectifier diodes 41 corresponding to the upper transformer 32 drops to zero, thus achieving zero-current switching. The system will enter the next operating state once the first power switching switch 211 corresponding to the upper resonant circuit 31 is turned off.

[0026] Referring to Figures 11 and 12, in the low-voltage output range shown in Figure 11, the half-bridge circuit of the upper primary side 321 and the lower primary side 341 is equivalent to the 0° switching state phase shift control signal of this converter with a 23° phase shift. This state is equivalent to the low-gain operation mode of the upper transformer 32 and the lower transformer 34 connected in parallel. In this mode, the input is transmitted to Vo through the lower resonant circuit 33 and then through the voltage doubler rectifier circuit on the secondary side. Therefore, the current of the upper first inductor 311 is equal to the excitation current, thus entering the decoupling region and not providing energy to the secondary side. In the high-voltage output range shown in Figure 12, the half-bridge circuit of the upper primary side 321 and the lower primary side 341 is equivalent to the 180° switching state of this converter with a 104° phase shift control signal. This state is equivalent to the high-gain operation mode of the upper transformer 32 and the lower transformer 34 connected in series. In this mode, the parasitic capacitance of one of the first power switching switches 211 has released all its energy, thus achieving ZVS flexible switching and turning on, while the second power switching switch 221 on the other side remains on, and the other first power switching switch 211 and the second power switching switch 221 are turned off. Through the current difference between the resonant inductors (the upper first inductor 311 and the lower first inductor 331) and the magnetizing inductors (the upper magnetizing inductor 313 and the lower magnetizing inductor 333), energy can be transferred to the secondary side, and the upper magnetizing inductor 313 and the lower magnetizing inductor 333 are thus clamped by the output voltage.

[0027] Referring to Figures 11 to 15, Figures 11 and 12 show the waveforms of this embodiment outputting 800 volts and 250 volts at 1000 watts, respectively, while Figures 13 and 14 show the waveforms of the conventional bridge rectifier outputting 800 volts and 250 volts at 1000 watts, respectively. As shown in Figure 15, the conventional bridge rectifier has poor output power below 300 watts, while the multi-resonant rectifier has unstable output power above 300 watts. Therefore, this embodiment proposes a 250-volt hybrid mode design, utilizing the switching diodes 52 of the switching module 5 as control switches to switch the multi-resonant mode under different load conditions. When the output power is below 300 watts, the multi-resonant mode (parallel resonance state) is activated, while when the power exceeds 300 watts, the mode is deactivated (non-conducting state). As shown in Figure 17, the efficiency performance is particularly outstanding under light loads below 300 watts, especially at a load of 100 watts, where the efficiency is improved to 87% compared to the conventional single-bridge rectifier.

[0028] In summary, in this embodiment of the resonant converter of the present invention, the upper secondary side 321 and the lower secondary side 341 use two ideal half-bridge LLC resonant circuits with identical component parameters. A switching module 5, representing a multi-resonant converter, is connected in parallel with the upper resonant circuit, so that the upper secondary side 322 and the lower secondary side 342 are connected in series and share a single quadrupole rectifier circuit module 4. Therefore, the lag arm power switch has ZVS characteristics, thereby reducing component losses and improving the efficiency of this embodiment. Simulation results show that the voltage multiplier mode can achieve the required output and input with less phase shift angle, while the multi-resonant mode improves the cycling energy that causes low efficiency under light load. Under constant voltage input, with a fixed operating frequency and a duty cycle of 50% including lag time, a wide range of output can be achieved by adjusting the phase shift between the leading arm 21 and the lagging arm 22. Therefore, the objective of the present invention is indeed achieved.

[0029] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification shall still fall within the scope of the patent of the present invention.

[0030] 1. Vcc: Power supply 2: Inverter circuit module 21: Forearm 211: First power switching switch 22: Lagging Arm 221: Second power switching switch 3: Resonant circuit module 31: Upper resonant circuit 311: Upper first inductor 312: Upper capacitor 313: Upper excitation inductor 32: Upper transformer 321: Last side 322: Upper secondary side 33: Lower resonant circuit 331: Lower side first inductor 332: Lower capacitor 333: Lower side magnetizing inductor 34: Lower Transformer 341: Next side 342: Lower secondary side 4: Quadruple voltage rectifier circuit module 41: Rectifier Diode 42: Rectifier voltage multiplier capacitor 43: Output filter capacitor 5: Switch Module 51: Parallel resonant circuit 52: Switching Diode 6: Signal Logic Circuit Module 7: Isolation circuit module 71: Optical Coupler Driver 72: Resistance 73: Diode VO: Voltage Level fn: Standardized frequency fr1: First resonant frequency fr2: Second resonant frequency Q1, Q3: High-end drive switches Q2, Q4: Low-end drive switches C1~C8: Capacitors D5, D6: Diodes

Claims

1. A system gain adjustment and wide output voltage power supply device, comprising: an inverter circuit module adapted to be connected to a power supply for providing an input voltage, and including a leading arm and a lagging arm; a resonant circuit module connected downstream of the inverter circuit module, and including an upper resonant circuit, an upper transformer connected to the upper resonant circuit, a lower resonant circuit connected to the upper resonant circuit, and a lower transformer connected to the lower resonant circuit for transforming the input voltage together with the upper transformer to output an output voltage; and a quaternary rectifier circuit module connected downstream of the resonant circuit module for rectifying the output voltage to output an operating voltage; A signal logic circuit module is connected to the inverter circuit module and is used to provide two control signals to the leading arm and the lagging arm respectively. The control signals are used to control the operating frequency, duty cycle and phase shift of the leading arm and the lagging arm respectively. A switching module is connected to the resonant circuit module and includes a parallel resonant circuit connected in parallel with the upper resonant circuit and two switching diodes connected to the parallel resonant circuit. The switching diodes are used to switch the switching module between a non-conducting state and a parallel resonant state that turns on the parallel resonant circuit.

2. The system gain adjustment and wide output voltage power supply device as described in claim 1, wherein, The inverter circuit module has two first power switching switches in the leading arm and two second power switching switches in the lagging arm. The signal logic circuit module is also used to adjust the lag time of the signal between any of the first power switching switches and any of the second power switching switches.

3. The system gain adjustment and wide output voltage power supply device as described in claim 2, wherein, The upper resonant circuit of the resonant circuit module has an upper first inductor, an upper capacitor connected in series with the upper first inductor, and an upper magnetizing inductor contained in the upper transformer itself. The lower resonant circuit has a lower first inductor, a lower capacitor connected in series with the lower first inductor, and a lower magnetizing inductor contained in the lower transformer itself.

4. The system gain adjustment and wide output voltage power supply device as described in claim 1 further includes an isolation circuit module connected between the signal logic circuit module and the inverter circuit module.

5. The system gain adjustment and wide output voltage power supply device as described in claim 1, wherein, The signal logic circuit module includes an adjustment circuit for receiving a reference voltage and adjusting the phase shift between the leading arm and the lagging arm.

6. The system gain adjustment and wide output voltage power supply device as described in claim 1, wherein, The upper transformer of the resonant circuit module has an upper primary side and an upper secondary side, while the lower transformer has a lower primary side and a lower secondary side.

7. The system gain adjustment and wide output voltage power supply device as described in claim 6, wherein, The upper primary side of the upper transformer is connected in parallel with the lower primary side of the lower transformer, while the upper secondary side of the upper transformer is connected in series with the lower secondary side of the lower transformer.

8. The system gain adjustment and wide output voltage power supply device as described in claim 1, wherein, The quadruple voltage multiplier rectifier circuit module includes four rectifier diodes, four voltage multiplier capacitors, and an output filter capacitor connected in parallel with the voltage multiplier capacitors. The quadruple voltage multiplier rectifier circuit module can switch between five operating states that are respectively connected to different numbers of the voltage multiplier capacitors.

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