Power supply circuit and power supply system

Abstract

The embodiment of the invention provides a power supply circuit and a power supply system, the circuit comprises a first power supply capacitor, a first bridge type output unit, a second power supply capacitor and a second bridge type output unit, each of the first bridge type output unit and the second bridge type output unit comprises two bridge arms, and each bridge arm comprises at least one switch tube. The first bridge type output unit is connected with the output end of the second bridge type output unit, and the first power supply capacitor is used for providing first input voltage for the first bridge type output unit; the second power supply capacitor is used for providing a second input voltage for the second bridge type output unit; the first bridge type output unit is used for adjusting a first input voltage through at least one switching tube on a bridge arm and outputting the adjusted first input voltage as a first output voltage; and the second bridge type output unit is used for adjusting a second input voltage through at least one switching tube on a bridge arm and outputting the adjusted second input voltage as a second output voltage.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of power electronics technology, and in particular to a power supply circuit and a power supply system. Background Art

[0002] At present, magnetic field coils are usually used to generate and confine plasma in the Experimental Superconducting Tokamak (EAST) or other plasma physics experimental devices. For example, the displacement signal generated by the plasma drift is tracked in real time through the power control output circuit, and the excitation current is provided to the magnetic field coil inside the vacuum chamber to form a magnetic field to maintain the dynamic balance and accurate position of the plasma when the cross section is non-circular, so as to suppress the rapid drift of the plasma in a large elongated shape. Therefore, in the plasma physics experimental device, the magnetic field coil needs to have strong current control and feedback capabilities, that is, a power supply that can quickly and flexibly control the output current and voltage is required. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a power supply circuit and a power supply system, which control the output voltage and current through a power supply capacitor in conjunction with a bridge output unit, thereby facilitating the subsequent rapid control of the plasma to solve the technical defects existing in the prior art.

[0004] According to a first aspect of an embodiment of the present application, a power supply circuit is provided, comprising a first power supply capacitor, a first bridge output unit connected to the first power supply capacitor, a second power supply capacitor, and a second bridge output unit connected to the second power supply capacitor, wherein the first bridge output unit and the second bridge output unit each comprise two bridge arms, each bridge arm comprises at least one switch tube, and the first bridge output unit is connected to an output end of the second bridge output unit, wherein:

[0005] The first power supply capacitor is used to provide a first input voltage to the first bridge output unit;

[0006] The second power supply capacitor is used to provide a second input voltage to the second bridge output unit;

[0007] The first bridge output unit is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as a first output voltage;

[0008] The second bridge output unit is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage.

[0009] In one embodiment, the first bridge output unit is composed of a first bridge arm and a second bridge arm connected in parallel, the first bridge arm is composed of a first switch tube and a first freewheeling diode connected in series, and the second bridge arm is composed of a second switch tube and a second freewheeling diode connected in series;

[0010] The second bridge output unit is composed of a third bridge arm and a fourth bridge arm connected in parallel, the third bridge arm is composed of a third switch tube and a third freewheeling diode connected in series, and the fourth bridge arm is composed of a fourth switch tube and a fourth freewheeling diode connected in series.

[0011] In one embodiment, the first bridge output unit is used to adjust the first input voltage through the first switch tube on the first bridge arm and / or the second switch tube on the second bridge arm, and output the adjusted first input voltage as the first output voltage;

[0012] The second bridge output unit is used to adjust the second input voltage through the third switch tube on the third bridge arm and / or the fourth switch tube on the fourth bridge arm, and output the adjusted second input voltage as the second output voltage.

[0013] In one embodiment, the emitter of the first switch tube is connected to the cathode of the first freewheeling diode, the collector of the first switch tube is connected to the cathode of the second freewheeling diode, the emitter of the second switch tube is connected to the anode of the first freewheeling diode, and the collector of the second switch tube is connected to the anode of the second freewheeling diode;

[0014] The emitter of the third switch tube is connected to the cathode of the third freewheeling diode, the collector of the third switch tube is connected to the cathode of the fourth freewheeling diode, the emitter of the fourth switch tube is connected to the anode of the third freewheeling diode, and the collector of the fourth switch tube is connected to the anode of the fourth freewheeling diode.

[0015] In one embodiment, the connection point between the first switch tube and the first freewheeling diode serves as the first positive output terminal of the first bridge output unit, and the connection point between the second switch tube and the second freewheeling diode serves as the first negative output terminal of the first bridge output unit;

[0016] The connection point between the third switch tube and the third freewheeling diode serves as the second positive output terminal of the second bridge output unit, and the connection point between the fourth switch tube and the fourth freewheeling diode serves as the second negative output terminal of the second bridge output unit.

[0017] In one embodiment, the first positive output terminal is a circuit positive output terminal, the first negative output terminal is connected to the second positive output terminal, and the second negative output terminal is a circuit negative output terminal.

[0018] In one embodiment, the positive electrode of the first power supply capacitor is connected to the collector of the first switch tube, and the negative electrode of the first power supply capacitor is connected to the emitter of the second switch tube;

[0019] The positive electrode of the second power supply capacitor is connected to the collector of the third switch tube, and the negative electrode of the second power supply capacitor is connected to the emitter of the fourth switch tube.

[0020] In one embodiment, the circuit further includes a first rectifying diode and a second rectifying diode, the first rectifying diode is connected in parallel with the first power supply capacitor, and the second rectifying diode is connected in parallel with the second power supply capacitor.

[0021] In one embodiment, the circuit further includes a first charging unit and a second charging unit, the first charging unit is connected in parallel with the first power supply capacitor, and the second charging unit is connected in parallel with the second power supply capacitor;

[0022] In one embodiment, the circuit further comprises a control unit, and the control unit is respectively connected to the first bridge output unit and the second bridge output unit;

[0023] The control unit is used to send control signals to the first bridge output unit and the second bridge output unit respectively, wherein the control signals are used to control the operating state of the switch tubes in the first bridge output unit and / or the second bridge output unit.

[0024] According to a second aspect of an embodiment of the present application, a power supply system is provided, the system comprising the above-mentioned power supply circuit, and the system further comprising a load.

[0025] It can be seen from the above technical solution that the present application provides a power supply circuit, which includes a first power supply capacitor, a first bridge output unit connected to the first power supply capacitor, a second power supply capacitor, and a second bridge output unit connected to the second power supply capacitor. The first bridge output unit and the second bridge output unit each include two bridge arms, each bridge arm includes at least one switch tube, and the first bridge output unit is connected to the output end of the second bridge output unit, wherein the first power supply capacitor is used to provide a first input voltage to the first bridge output unit; the second power supply capacitor is used to provide a second input voltage to the second bridge output unit; the first bridge output unit is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as the first output voltage; the second bridge output unit is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage.

[0026] The embodiment of the present application realizes using the first power supply capacitor and the second power supply capacitor as energy storage units, and adjusting the input voltage in combination with the first bridge output unit and the second bridge output unit, thereby realizing flexible control of the output voltage, and the circuit structure is relatively simple, easy to implement, and highly reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without paying any creative work.

[0028] Figure 1 is a circuit schematic diagram of a power supply circuit provided by an embodiment of the present application;

[0029] Figure 2 It is a system schematic diagram of a power supply system provided by an embodiment of the present application.

[0030] Reference numerals

[0031] 102-first power supply capacitor, 104-first rectifier diode, 20-first bridge output unit, 202-first switch tube, 204-first freewheeling diode, 206-second freewheeling diode, 208-second switch tube, 302-second power supply capacitor, 304-second rectifier diode, 40-second bridge output unit, 402-third switch tube, 404-third freewheeling diode, 406-fourth freewheeling diode, 408-fourth switch tube, 50-load, 60-power supply system, 602-power supply circuit, 604-load. DETAILED DESCRIPTION

[0032] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0033] The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "a", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items.

[0034] It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0035] At present, in plasma physics experimental devices, such as Tokamak (Tokamak) experimental devices, magnetic field coils are usually used to generate and constrain plasma. The current in the magnetic field coil is usually driven by a pulse power supply system, and the plasma physics experimental device usually includes: toroidal field (Toroidal Field, referred to as TF) coil, poloidal field (Poloidal Field, referred to as PF) coil, etc., wherein the PF coil plays a major role in the confinement of plasma, and the position of plasma in the vacuum chamber can be controlled by the PF coil, and the plasma is subjected to complex parameter control, etc. Therefore, it is necessary to have a strong current control and feedback capability of the PF coil. In the existing physical experimental device, AC-DC (Alternating Current-Direct Current, AC-DC) converter systems such as power grid power supply or flywheel motors are generally used to provide the required power supply. However, these systems usually have a high load capacity requirement for power supply, and the circuit structure is complex, making the cost higher.

[0036] Based on this, in the present application, a power supply circuit is provided, which can be applied to a plasma physics experimental device to provide the required voltage and current, so as to solve the problem of complex structure and high cost of the power supply circuit in the existing plasma physics experimental device. The technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] See also Figure 1 , Figure 1 A circuit schematic diagram of a power supply circuit provided according to an embodiment of the present application is shown, wherein the circuit includes a first power supply capacitor 102, a first bridge output unit 20 connected to the first power supply capacitor 102, a second power supply capacitor 202, and a second bridge output unit 40 connected to the second power supply capacitor. The first bridge output unit 20 and the second bridge output unit 40 each include two bridge arms, each bridge arm includes at least one switch tube, and the first bridge output unit 20 is connected to the output end 40 of the second bridge output unit, wherein:

[0038] The first power supply capacitor 102 is used to provide a first input voltage to the first bridge output unit 20; the second power supply capacitor 202 is used to provide a second input voltage to the second bridge output unit 40;

[0039] In practical applications, during the discharge process of the plasma physics experimental device, the current needs to rise rapidly in the initial stage, and when the current reaches a certain value, the power supply needs to continue to discharge slowly. Therefore, the demand for the plasma physics experimental device can be understood as requiring the power supply to provide a rapidly rising output current, and to be able to continuously provide a gentle output current after a period of time. Under this requirement, the power supply circuit provided in the present application adopts a mixed cascade of a first power supply capacitor and a second power supply capacitor to supply power.

[0040] In a specific implementation, the first power supply capacitor and the second power supply capacitor are used as energy storage units to provide input voltages to the first bridge output unit and the second bridge output unit respectively. Figure 1 In the figure, the input capacitor voltage of the first power supply capacitor is U1, and the input capacitor voltage of the second power supply capacitor is U2. The first power supply capacitor provides a first input voltage U1 to the first bridge output unit, and the second power supply capacitor provides a second input voltage U2 to the second bridge output unit. In the actual application of this power supply circuit, the first power supply capacitor is an electrolytic capacitor, and the second power supply capacitor is a supercapacitor. The supercapacitor has a higher capacity than the electrolytic capacitor. The supercapacitor has the characteristics of fast charging and discharging of capacitors and the energy storage characteristics of batteries. Therefore, in one embodiment of the present application, the second input voltage provided by the second power supply capacitor is much greater than the first input voltage provided by the first power supply capacitor. When the output voltage is subsequently provided to the load, it also mainly depends on the second input voltage provided by the second power supply capacitor. By using two power supply capacitors as energy storage units, the charging and discharging of the capacitors can be realized through a mature programmable DC power supply and a resistance discharge system, thereby achieving efficient energy conversion.

[0041] After the first power supply capacitor provides the first input voltage to the first bridge output unit, the first bridge output unit can adjust the first input voltage through at least one switch tube on the bridge arm. Specifically, the first bridge output unit 20 is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as the first output voltage.

[0042] Correspondingly, after the second power supply capacitor provides the second input voltage to the second bridge output unit, the second bridge output unit can also adjust the second input voltage through at least one switch tube on the bridge arm. Specifically, the second bridge output unit 20 is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage.

[0043] In practical applications, the first bridge output unit is a high voltage bridge unit module powered by an electrolytic capacitor, which is used to provide a current with a high rate of change, and the second bridge output unit is a low voltage bridge unit module powered by a supercapacitor, which is used to provide a flat-top current. Figure 1It can be seen that the first bridge output unit and the second bridge output unit each include two bridge arms, each bridge arm includes a switch tube and a diode, and the output voltage and current can be controlled by controlling the on and off of the switch tube in the bridge output unit.

[0044] In specific implementation, the first bridge output unit is composed of a first bridge arm and a second bridge arm in parallel, the first bridge arm is composed of a first switch tube and a first freewheeling diode in series, and the second bridge arm is composed of a second switch tube and a second freewheeling diode in series; the second bridge output unit is composed of a third bridge arm and a fourth bridge arm in parallel, the third bridge arm is composed of a third switch tube and a third freewheeling diode in series, and the fourth bridge arm is composed of a fourth switch tube and a fourth freewheeling diode in series.

[0045] Among them, the switching tubes in the first bridge output unit and the second bridge output unit are both IBGT (Insulated Gate Bipolar Transistor) switching tubes, and IGBT switching tubes are used as switching devices. Compared with traditional thyristors and other devices, traditional thyristors are easy to turn on, but require specially designed circuits for control when turned off. They are not suitable for circuits with high control requirements on input voltage. IBGT switching tubes have the advantages of full switch control, simple driving, and high switching frequency, and are suitable for series and parallel use to increase capacity.

[0046] In practical applications, the first bridge output unit 20 includes a first bridge arm and a second bridge arm. Each bridge arm in the first bridge output unit is composed of a switch tube and a freewheeling diode connected in series. Figure 1 The first switch tube 202 and the first freewheeling diode 204 constitute the first bridge arm of the first bridge output unit 20, and the second switch tube 208 and the second freewheeling diode 206 constitute the second bridge arm of the first bridge output unit 20. The second bridge output unit 40 includes a third bridge arm and a fourth bridge arm. Each bridge arm of the second bridge output unit 40 is composed of a switch tube and a freewheeling diode connected in series. Figure 1 The third switch tube 402 and the third freewheeling diode 404 constitute the third bridge arm of the second bridge output unit 40 , and the fourth switch tube 408 and the fourth freewheeling diode 406 constitute the fourth bridge arm of the second bridge output unit 40 .

[0047] During specific implementation, the first freewheeling diode, the second freewheeling diode, the third freewheeling diode and the fourth freewheeling diode all have the function of automatically continuing the current when the switch tube is turned off, so as to ensure that there will be no direct short circuit in the bridge arm. For example, when the first switch tube is turned off, the first freewheeling diode automatically continues the current to ensure that there will be no short circuit in the first bridge arm. In one embodiment of the present application, a switch tube and a freewheeling diode are respectively deployed in series on each bridge arm. This deployment method is suitable for the case of unidirectional current and bidirectional voltage, that is, two-quadrant output. When four-quadrant output is required, the freewheeling diode on each bridge arm can be replaced with an IGBT switch tube, that is, the first bridge output unit and the second bridge output unit are transformed from a half-controlled half-bridge circuit to a fully controlled full bridge. In this case, the first bridge arm and the second bridge arm of the first bridge output unit respectively include two switch tubes, and the third bridge arm and the fourth bridge arm of the second bridge output unit respectively include two switch tubes.

[0048] Based on this, through the cascade bridge power supply powered by the first power supply capacitor and the second power supply capacitor respectively, the output voltage and current can be flexibly controlled, thereby realizing rapid control of plasma in the plasma experimental device.

[0049] Furthermore, in order to ensure that the output voltage and current can be accurately controlled, the output voltage and current can be controlled by the operating state of the switch tube on the bridge arm. Specifically, the first bridge output unit is used to adjust the first input voltage through the first switch tube on the first bridge arm and / or the second switch tube on the second bridge arm, and output the adjusted first input voltage as the first output voltage; the second bridge output unit is used to adjust the second input voltage through the third switch tube on the third bridge arm and / or the fourth switch tube on the fourth bridge arm, and output the adjusted second input voltage as the second output voltage.

[0050] In practical applications, the first bridge output unit and the second bridge output unit can control the on or off of the switch tube by PWM (pulse width modulation) mode, so as to change the power output. In specific implementation, a three-level step wave (-U, 0, +U) with the input capacitor voltage U as a unit is output. The specific relationship between the first switch tube, the second switch tube, the third switch tube and the fourth switch tube and the power output voltage can be seen in Table 1.

[0051] Table 1

[0052]

[0053]

[0054] The output voltage Uo can be understood as being generated by the first output voltage U1 output by the first bridge output unit and the second output voltage U2 output by the second bridge output unit, see Figure 1 , the output voltage Uo is the voltage across the load 50. The load 50 in one embodiment of the present application can be understood as a PF coil, that is, Figure 1 The load 50 in the embodiment is composed of a resistor and an inductor. It should be noted that the present application does not impose any specific restrictions on the composition of the load. The power supply circuit provided in the present application is used to provide output voltage and current to the load.

[0055] When the first switch tube 202, the second switch tube 208, the third switch tube 402, and the fourth switch tube 408 are all turned on, the output voltage Uo is U1+U2; when the first switch tube 202, the second switch tube 208, and the third switch tube 402 are all turned on, and the other switch tubes are turned off, the output voltage Uo is U1; when the first switch tube 202, the third switch tube 402, and the fourth switch tube 408 are all turned on, and the other switch tubes are turned off, the output voltage Uo is U2; When the first switch tube 202 and the third switch tube 402 are both turned on and the other switches are turned off, or the second switch tube 208 and the fourth switch tube 408 are both turned on and the other switches are turned off, the output voltage is 0; when the second switch tube 208 is turned on and the other switches are turned off, the output voltage is -U2; when the fourth switch tube 408 is turned on and the other switches are turned off, the output voltage Uo is -U1; when all the switches are turned off, the output voltage Uo is -U1-U2. It should be noted that in order to avoid energy backflow between capacitor banks, which may damage the device, the two switching modes U1-U2 and U2-U1 are cancelled and prohibited.

[0056] Based on this, by controlling the switching coordination of the switching tubes in the first bridge output unit and the second bridge output unit, the voltage of the output voltage can be accurately adjusted, which is beneficial to the subsequent precise control of the plasma.

[0057] Furthermore, in order to ensure that the output voltage can be controlled according to the on and off of the switch tube, it is necessary to determine the connection method of the switch tube in the bridge output unit, specifically, the emitter of the first switch tube is connected to the cathode of the first freewheeling diode, the collector of the first switch tube is connected to the cathode of the second freewheeling diode, the emitter of the second switch tube is connected to the anode of the first freewheeling diode, and the collector of the second switch tube is connected to the anode of the second freewheeling diode; the emitter of the third switch tube is connected to the cathode of the third freewheeling diode, the collector of the third switch tube is connected to the cathode of the fourth freewheeling diode, the emitter of the fourth switch tube is connected to the anode of the third freewheeling diode, and the collector of the fourth switch tube is connected to the anode of the fourth freewheeling diode.

[0058] See also Figure 1 In the first bridge output unit 20, the emitter of the first switch tube 202 is connected to the cathode of the first freewheeling diode 204, and the collector of the first switch tube 202 is connected to the cathode of the second freewheeling diode 206; the emitter of the second switch tube 208 is connected to the anode of the first freewheeling diode 204, and the collector of the second switch tube 208 is connected to the anode of the second freewheeling diode 206.

[0059] In the second bridge output unit 40, the emitter of the third switch tube 402 is connected to the cathode of the third freewheeling diode 404, and the collector of the third switch tube 402 is connected to the cathode of the fourth freewheeling diode 406; the emitter of the fourth switch tube 408 is connected to the anode of the third freewheeling diode 404, and the collector of the fourth switch tube 408 is connected to the anode of the fourth freewheeling diode 406.

[0060] Based on this, through the connection method between the switch tube and the freewheeling diode, when the output voltage can be controlled by the switch tube, the occurrence of a bridge arm short circuit when the switch tube is turned off can be avoided, thereby ensuring that the power supply circuit can work normally.

[0061] Furthermore, in order to ensure that the first bridge output unit and the second bridge output unit can output corresponding output voltages, it is necessary to determine output ends in the first bridge output unit and the second bridge output unit. Specifically, the connection between the first switch tube and the first freewheeling diode serves as the first positive output end of the first bridge output unit, and the connection between the second switch tube and the second freewheeling diode serves as the first negative output end of the first bridge output unit; the connection between the third switch tube and the third freewheeling diode serves as the second positive output end of the second bridge output unit, and the connection between the fourth switch tube and the fourth freewheeling diode serves as the second negative output end of the second bridge output unit.

[0062] Among them, the first positive output terminal and the first negative output terminal can be understood as the two output terminals of the first bridge output unit, which are used to output the first output voltage of the first bridge output unit, and the second positive output terminal and the second negative output terminal can be understood as the two output terminals of the second bridge output single-ended unit, which are used to output the second output unit of the second bridge output unit.

[0063] In a specific implementation, the connection between the first switch tube 202 and the first freewheeling diode 204 serves as the first positive output terminal of the first bridge output unit 20. Figure 1 , Figure 1 The connection point between the first switch tube 202 and the first freewheeling diode 204 is point A; the connection point between the second switch tube 208 and the second freewheeling diode 206 serves as the first negative output terminal of the first bridge output unit 20. Figure 1 The connection point between the second switch tube 208 and the second freewheeling diode 206 is point B; the connection point between the third switch tube 402 and the third freewheeling diode 404 is the second positive output terminal of the second bridge output unit 40. Figure 1 The connection point between the third switch tube 402 and the third freewheeling diode 404 is point C; the connection point between the fourth switch tube 408 and the fourth freewheeling diode 406 serves as the second negative output terminal of the second bridge output unit 40. Figure 1 The connection point between the fourth switch tube 408 and the fourth freewheeling diode 406 is point D.

[0064] In one embodiment of the present application, the power supply circuit is a cascade bridge power supply powered by a first power supply capacitor and a second power supply capacitor, respectively, so the output end of the first bridge output unit is connected to the output end of the second bridge output unit, thereby realizing the output of a three-level step wave. Specifically, the first positive output end is the positive output end of the circuit, the first negative output end is connected to the second positive output end, and the second negative output end is the negative output end of the circuit.

[0065] The positive output terminal of the circuit can be understood as the positive output terminal of the power supply circuit, and the negative output terminal of the circuit can be understood as the negative output terminal of the power supply circuit. The first positive output terminal of the first bridge output unit 20 is used as the positive output terminal of the circuit, and the first negative output terminal of the first bridge output unit 20 is connected to the second positive output terminal of the second bridge output unit 40, and the second negative output terminal of the second bridge output unit 40 is used as the negative output terminal of the circuit. The circuit output voltage Uo generated by the first output voltage and the second output voltage respectively output by the first bridge output unit 20 and the second bridge output unit 40 can be obtained through the positive output terminal of the circuit and the negative output terminal of the circuit.

[0066] In practical applications, the number of output levels of the traditional double-bridge unit series connection is 5, while the circuit topology of the mixed-input double-bridge unit (2H-bridge module) series connection can increase the number of levels to 7, making the output waveform smoother.

[0067] Furthermore, in order to ensure that the first power supply capacitor can supply power to the first bridge output unit and the second power supply capacitor can supply power to the second bridge output unit, it is necessary to connect the first power supply capacitor in parallel with the first bridge output unit and the second power supply capacitor in parallel with the second bridge output unit. Specifically, the positive electrode of the first power supply capacitor is connected to the collector of the first switch tube, and the negative electrode of the first power supply capacitor is connected to the emitter of the second switch tube; the positive electrode of the second power supply capacitor is connected to the collector of the third switch tube, and the negative electrode of the second power supply capacitor is connected to the emitter of the fourth switch tube.

[0068] Among them, the positive electrode of the first power supply capacitor 102 is connected to the collector of the first switch tube 202, and the negative electrode of the first power supply capacitor 102 is connected to the emitter of the second switch tube 208, so that the first power supply capacitor 102 can be connected in parallel with the first bridge output unit 20, so that the first power supply capacitor 102 can provide the first input voltage to the first bridge output unit 20; the positive electrode of the second power supply capacitor 302 is connected to the collector of the third switch tube, and the negative electrode of the second power supply capacitor 302 is connected to the emitter of the fourth switch tube 408, so that the second power supply capacitor 302 can be connected in parallel with the second bridge output unit 20, so that the second power supply capacitor 302 can provide the second input voltage to the second bridge output unit 40.

[0069] Based on this, by connecting the first power supply capacitor in parallel with the first bridge output unit, the first power supply capacitor can provide a first input voltage to the first bridge output unit, so that the first bridge output unit can subsequently output a first output voltage based on the first input voltage; by connecting the second power supply capacitor in parallel with the second bridge output unit, the second power supply capacitor can provide a second input voltage to the second bridge output unit, so that the second bridge output unit can subsequently output a second output voltage based on the second input voltage.

[0070] Furthermore, in order to prevent the inductive current generated by the inductance in the coil when the switch tube is turned off, that is, the circuit output current is reduced, from damaging the power supply capacitor, a rectifier diode can be connected in parallel at both ends of the power supply capacitor. Specifically, the circuit also includes a first rectifier diode and a second rectifier diode. The first rectifier diode is connected in parallel with the first power supply capacitor, and the second rectifier diode is connected in parallel with the second power supply capacitor.

[0071] The first rectifier diode is a diode connected in parallel with both sides of the first power supply capacitor, and the second rectifier diode is a diode connected in parallel with both sides of the second power supply capacitor. In practical applications, when the output current decreases, the inductance in the load coil will generate an induced current. In order to prevent the induced current from causing reverse damage to the power supply capacitor, a rectifier diode can be connected in reverse parallel at both ends of the power supply capacitor. For details, see Figure 1 A first rectifier diode 104 is connected in parallel across the first power supply capacitor 102, and a second rectifier diode 304 is connected in parallel across the second power supply capacitor 302, so that the reverse induced current can flow into and out of the rectifier diode, avoiding reverse voltage damage to the power supply capacitor.

[0072] Furthermore, in order to ensure that the power supply capacitor can be discharged normally and thus provide input voltage for the bridge output unit, the power supply capacitor needs to be charged. Specifically, the circuit also includes a first charging unit and a second charging unit. The first charging unit is connected in parallel with the first power supply capacitor, and the second charging unit is connected in parallel with the second power supply capacitor. The first charging unit is used to provide a first charging current to the first power supply capacitor; the second charging unit is used to provide a second charging current to the second power supply capacitor.

[0073] Among them, the first charging unit can be understood as a charging module for charging the first charging capacitor, and the second charging unit can be understood as a charging module for charging the second charging capacitor. In practical applications, the first charging unit and the second charging unit can be programmable DC power supplies. When the power supply capacitor needs to be charged, the power supply capacitor is powered by the programmable DC power supply. In specific implementation, the first charging unit is connected in parallel with the first power supply capacitor 102, and the second charging unit is connected in parallel with the second power supply capacitor 302.

[0074] Based on this, by connecting charging units in parallel on both sides of the power supply capacitor, the power supply capacitor is charged, ensuring that the subsequent power supply capacitor can normally discharge the bridge output unit to provide the corresponding input voltage.

[0075] Furthermore, in order to accurately control the output voltage, it is necessary to accurately control the operating state of the switch tube in the bridge output unit. Specifically, the circuit also includes a control unit, which is respectively connected to the first bridge output unit and the second bridge output unit; the control unit is used to send control signals to the first bridge output unit and the second bridge output unit respectively, wherein the control signal is used to control the operating state of the switch tube in the first bridge output unit and / or the second bridge output unit.

[0076] The control unit may be understood as a unit module that sends a control signal to the bridge output unit. The control signal may enable the switch tube in the bridge output unit to operate in different states, such as an on state or an off state.

[0077] In actual applications, the control unit includes a high-performance MCU (Microcontroller Unit). The MCU collects the capacitor voltage at both ends of the power supply capacitor, the output voltage on the load side, and the output circuit, and generates a PWM signal to drive the IGBT switch tube in the bridge output unit, thereby controlling the on and off of the switch tube to adjust the output voltage and current according to actual needs.

[0078] During specific implementation, the control unit can also communicate with the host computer serial port, and the host computer can display power circuit monitoring information to the user, such as input voltage, output voltage, output current, operating status of each switch tube, etc., so that the user can understand the current operating status of the power circuit.

[0079] The present application provides a power supply circuit, including a first power supply capacitor, a first bridge output unit connected to the first power supply capacitor, a second power supply capacitor, and a second bridge output unit connected to the second power supply capacitor, wherein the first bridge output unit and the second bridge output unit each include two bridge arms, each bridge arm includes at least one switch tube, and the first bridge output unit is connected to the output end of the second bridge output unit, wherein the first power supply capacitor is used to provide a first input voltage to the first bridge output unit; the second power supply capacitor is used to provide a second input voltage to the second bridge output unit; the first bridge output unit is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as the first output voltage; the second bridge output unit is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage. The first power supply capacitor and the second power supply capacitor are used as energy storage units, and the input voltage is adjusted in combination with the first bridge output unit and the second bridge output unit, so as to realize flexible control of the power supply output voltage with a simple circuit structure, and the circuit structure is relatively simple, easy to implement, and highly reliable.

[0080] Based on the power supply circuit provided in the above embodiments, the present application also provides a power supply system, which includes the power supply circuit described in any of the above embodiments and also includes a load. Figure 2 , Figure 2 A system schematic diagram of a power supply system provided according to an embodiment of the present application is shown, wherein the power supply system 60 includes a power supply circuit 602 and a load 604 , and the power supply circuit 602 is used to provide output voltage and current to the load 604 .

[0081] In one embodiment, the power supply circuit 602 includes: a first power supply capacitor, a first bridge output unit connected to the first power supply capacitor, a second power supply capacitor, and a second bridge output unit connected to the second power supply capacitor, wherein the first bridge output unit and the second bridge output unit each include two bridge arms, each bridge arm includes at least one switch tube, and the first bridge output unit is connected to the output end of the second bridge output unit, wherein the first power supply capacitor is used to provide a first input voltage to the first bridge output unit; the second power supply capacitor is used to provide a second input voltage to the second bridge output unit; the first bridge output unit is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as the first output voltage; the second bridge output unit is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage.

[0082] In one embodiment, the first bridge output unit is composed of a first bridge arm and a second bridge arm in parallel, the first bridge arm is composed of a first switch tube and a first freewheeling diode in series, and the second bridge arm is composed of a second switch tube and a second freewheeling diode in series; the second bridge output unit is composed of a third bridge arm and a fourth bridge arm in parallel, the third bridge arm is composed of a third switch tube and a third freewheeling diode in series, and the fourth bridge arm is composed of a fourth switch tube and a fourth freewheeling diode in series.

[0083] In one embodiment, the first bridge output unit is used to adjust the first input voltage through the first switch tube on the first bridge arm and / or the second switch tube on the second bridge arm, and output the adjusted first input voltage as the first output voltage; and the second bridge output unit is used to adjust the second input voltage through the third switch tube on the third bridge arm and / or the fourth switch tube on the fourth bridge arm, and output the adjusted second input voltage as the second output voltage.

[0084] In one embodiment, the emitter of the first switch tube is connected to the cathode of the first freewheeling diode, the collector of the first switch tube is connected to the cathode of the second freewheeling diode, the emitter of the second switch tube is connected to the anode of the first freewheeling diode, and the collector of the second switch tube is connected to the anode of the second freewheeling diode; the emitter of the third switch tube is connected to the cathode of the third freewheeling diode, the collector of the third switch tube is connected to the cathode of the fourth freewheeling diode, the emitter of the fourth switch tube is connected to the anode of the third freewheeling diode, and the collector of the fourth switch tube is connected to the anode of the fourth freewheeling diode.

[0085] In one embodiment, the connection between the first switch tube and the first freewheeling diode serves as the first positive output terminal of the first bridge output unit, and the connection between the second switch tube and the second freewheeling diode serves as the first negative output terminal of the first bridge output unit; the connection between the third switch tube and the third freewheeling diode serves as the second positive output terminal of the second bridge output unit, and the connection between the fourth switch tube and the fourth freewheeling diode serves as the second negative output terminal of the second bridge output unit.

[0086] In one embodiment, the first positive output terminal is a circuit positive output terminal, the first negative output terminal is connected to the second positive output terminal, and the second negative output terminal is a circuit negative output terminal.

[0087] In one embodiment, the positive electrode of the first power supply capacitor is connected to the collector of the first switching tube, and the negative electrode of the first power supply capacitor is connected to the emitter of the second switching tube; the positive electrode of the second power supply capacitor is connected to the collector of the third switching tube, and the negative electrode of the second power supply capacitor is connected to the emitter of the fourth switching tube.

[0088] In one embodiment, the power supply circuit 602 further includes a first rectifier diode and a second rectifier diode, the first rectifier diode is connected in parallel with the first power supply capacitor, and the second rectifier diode is connected in parallel with the second power supply capacitor.

[0089] In one embodiment, the power supply circuit 602 also includes a first charging unit and a second charging unit, the first charging unit is connected in parallel with the first power supply capacitor, and the second charging unit is connected in parallel with the second power supply capacitor; the first charging unit is used to provide a first charging current to the first power supply capacitor; the second charging unit is used to provide a second charging current to the second power supply capacitor.

[0090] In one embodiment, the power supply circuit 602 also includes a control unit, which is respectively connected to the first bridge output unit and the second bridge output unit; the control unit is used to send control signals to the first bridge output unit and the second bridge output unit respectively, wherein the control signal is used to control the operating state of the switch tube in the first bridge output unit and / or the second bridge output unit.

[0091] A power supply system provided in the present application realizes the use of a first power supply capacitor and a second power supply capacitor as energy storage units, and adjusts the input voltage in combination with a first bridge output unit and a second bridge output unit, thereby realizing flexible control of the output voltage, and the power supply circuit structure is relatively simple, easy to implement, and highly reliable.

[0092] In this application, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present application will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

[0093] It should be noted that, for the convenience of description, the aforementioned method embodiments are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the present application are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0094] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0095] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The optional embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can understand and use the present application well. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A power supply circuit, characterized in that: The circuit includes a first power supply capacitor, a first bridge output unit connected to the first power supply capacitor, a second power supply capacitor, and a second bridge output unit connected to the second power supply capacitor. The first bridge output unit and the second bridge output unit each include two bridge arms, each bridge arm includes at least one switch tube, and the first bridge output unit is connected to the output end of the second bridge output unit, wherein: The first power supply capacitor is used to provide a first input voltage to the first bridge output unit; The second power supply capacitor is used to provide a second input voltage to the second bridge output unit; The first bridge output unit is used to adjust the first input voltage through at least one switch tube on the bridge arm, and output the adjusted first input voltage as a first output voltage; The second bridge output unit is used to adjust the second input voltage through at least one switch tube on the bridge arm, and output the adjusted second input voltage as the second output voltage.

2. The circuit according to claim 1, characterized in that The first bridge output unit is composed of a first bridge arm and a second bridge arm connected in parallel, the first bridge arm is composed of a first switch tube and a first freewheeling diode connected in series, and the second bridge arm is composed of a second switch tube and a second freewheeling diode connected in series; The second bridge output unit is composed of a third bridge arm and a fourth bridge arm connected in parallel, the third bridge arm is composed of a third switch tube and a third freewheeling diode connected in series, and the fourth bridge arm is composed of a fourth switch tube and a fourth freewheeling diode connected in series.

3. The circuit according to claim 2, characterized in that The first bridge output unit is used to adjust the first input voltage through the first switch tube on the first bridge arm and / or the second switch tube on the second bridge arm, and output the adjusted first input voltage as a first output voltage; The second bridge output unit is used to adjust the second input voltage through the third switch tube on the third bridge arm and / or the fourth switch tube on the fourth bridge arm, and output the adjusted second input voltage as the second output voltage.

4. The circuit according to claim 2, characterized in that The emitter of the first switch tube is connected to the cathode of the first freewheeling diode, the collector of the first switch tube is connected to the cathode of the second freewheeling diode, the emitter of the second switch tube is connected to the anode of the first freewheeling diode, and the collector of the second switch tube is connected to the anode of the second freewheeling diode; The emitter of the third switch tube is connected to the cathode of the third freewheeling diode, the collector of the third switch tube is connected to the cathode of the fourth freewheeling diode, the emitter of the fourth switch tube is connected to the anode of the third freewheeling diode, and the collector of the fourth switch tube is connected to the anode of the fourth freewheeling diode.

5. The circuit according to claim 2, characterized in that The connection point between the first switch tube and the first freewheeling diode serves as the first positive output terminal of the first bridge output unit, and the connection point between the second switch tube and the second freewheeling diode serves as the first negative output terminal of the first bridge output unit; The connection point between the third switch tube and the third freewheeling diode serves as the second positive output terminal of the second bridge output unit, and the connection point between the fourth switch tube and the fourth freewheeling diode serves as the second negative output terminal of the second bridge output unit.

6. The circuit according to claim 5, characterized in that The first positive output terminal is a positive output terminal of the circuit, the first negative output terminal is connected to the second positive output terminal, and the second negative output terminal is a negative output terminal of the circuit.

7. The circuit according to claim 2, characterized in that The positive electrode of the first power supply capacitor is connected to the collector of the first switch tube, and the negative electrode of the first power supply capacitor is connected to the emitter of the second switch tube; The positive electrode of the second power supply capacitor is connected to the collector of the third switch tube, and the negative electrode of the second power supply capacitor is connected to the emitter of the fourth switch tube.

8. The circuit according to claim 1, characterized in that The circuit further includes a first rectifying diode and a second rectifying diode, wherein the first rectifying diode is connected in parallel with the first power supply capacitor, and the second rectifying diode is connected in parallel with the second power supply capacitor.

9. The circuit according to claim 1, characterized in that The circuit further includes a first charging unit and a second charging unit, the first charging unit is connected in parallel with the first power supply capacitor, and the second charging unit is connected in parallel with the second power supply capacitor; The first charging unit is used to provide a first charging current to the first power supply capacitor; The second charging unit is used to provide a second charging current to the second power supply capacitor.

10. The circuit according to claim 1, characterized in that The circuit further comprises a control unit, wherein the control unit is respectively connected to the first bridge output unit and the second bridge output unit; The control unit is used to send control signals to the first bridge output unit and the second bridge output unit respectively, wherein the control signals are used to control the operating state of the switch tubes in the first bridge output unit and / or the second bridge output unit.

11. A power supply system, characterized in that: The system comprises the power supply circuit according to any one of claims 1 to 10, and the system further comprises a load.

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