Power supply voltage adjusting device based on inverter circuit

Abstract

The embodiment of the invention provides a power supply voltage regulating device based on an inverter circuit, which comprises an input circuit, a voltage regulating circuit, an inverter circuit and a follow current circuit, and is characterized in that the input circuit filters input alternating current and outputs the alternating current through the output end of the input circuit; the voltage regulating circuit regulates input alternating current by modulating the working states of switching devices in the first switching device group and the second switching device group, and the output end of the voltage regulating circuit outputs voltage and serves as the output end of the power supply voltage regulating device based on the inverter circuit to supply power to a load; the inverter circuit is configured to adjust reactive current and harmonic current of the input alternating current or the output end of the power supply voltage adjusting device; the freewheeling circuit is configured to enable the voltage regulating circuit and the inverter circuit to form a freewheeling path to absorb overvoltage and peak voltage generated by the voltage regulating circuit. The embodiment of the invention is simple in structure, effectively guarantees the stability of the power grid voltage, and has the advantages of quick response, low cost, simple and convenient control, high reliability and the like.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of power generation, power transformation or power distribution, and specifically to a power supply voltage regulating device based on an inverter circuit. Background Art

[0002] With the continuous development of the economy, electricity consumption has increased annually, especially for residential users. However, the upgrading and renovation of power distribution lines in factories, mines, residential communities, and shops has lagged behind, resulting in substandard voltage at the end of the lines, large voltage fluctuations, and frequent grid overloads. This makes it difficult for some electrical equipment to function properly, easily causing damage. In addition, the high reactive power requirements of newly added equipment such as motors and compressors generate large amounts of high-order harmonic currents, increasing low-voltage line losses, reducing the grid power factor, and exacerbating supply voltage fluctuations.

[0003] To address low voltage and voltage fluctuations, a related technical solution is to install a power supply voltage stabilizer on the distribution network. This automatic voltage regulator can adjust the supply voltage in real time, stabilizing it at a standard value. This device directly provides reactive power to power users, increasing the distribution network's transmission capacity and enhancing the operational safety of power transformers. It can also significantly reduce voltage fluctuations caused by lightning strikes, short circuits, and other factors, protecting power users.

[0004] However, in the process of real-time adjustment of power supply through the voltage automatic adjustment device of related technology, there is often circuit impedance mismatch, ripple, noise and other conditions. The related technology has not yet proposed an effective technical solution and urgently needs to be improved. Summary of the Invention

[0005] The main purpose of the embodiments of the present application is to provide a power supply voltage regulation device based on an inverter circuit to solve the problems of circuit impedance mismatch, ripple, noise, etc. in real-time power supply regulation in related technologies.

[0006] According to a first aspect of an embodiment of the present application, a power supply voltage regulation device based on an inverter circuit is provided, the device including an input circuit, a voltage regulating circuit, an inverter circuit, and a freewheeling circuit; the input circuit including an input end, an output end, and a common end, the input end being coupled to one end of the input alternating current, the common end being coupled to the other end of the input alternating current, or a neutral line, the input circuit filtering the input alternating current and outputting it through the output end of the input circuit; the voltage regulating circuit including a first switching device group and a second switching device group, the first switching device group and the second switching device group being coupled in series to form a series circuit, one end point of the series circuit being coupled to the output end of the input circuit, the other end point of the series circuit being coupled to the other end of the input alternating current or a neutral line, and the midpoint of the series circuit serving as the output end of the voltage regulating circuit; the voltage regulating circuit filters the input alternating current by connecting the first switching device group and the second switching device group in series. The modulation of the working state of the switching devices in the switching device group realizes the regulation of the input AC power, and outputs the voltage through the output end of the voltage regulating circuit, and at the same time serves as the output end of the power supply voltage regulation device based on the inverter circuit to supply power to the load; the inverter circuit includes two AC ports and two DC ports, and the two DC ports of the inverter circuit are respectively coupled to the two DC ports of the freewheeling circuit, and the inverter circuit is configured to regulate the DC voltage input to the inverter circuit, regulate the input AC power or the reactive current and harmonic current of the output end of the power supply voltage regulation device; the freewheeling circuit includes an input port and two DC ports, the input port of the freewheeling circuit is coupled to the voltage regulating circuit, and the two DC ports of the freewheeling circuit are coupled to the two DC ports of the inverter circuit, and the freewheeling circuit is configured to form a freewheeling path between the voltage regulating circuit and the inverter circuit to absorb the overvoltage and peak voltage generated by the voltage regulating circuit.

[0007] Optionally, the first switching device group of the voltage regulating circuit includes a first transistor and a second transistor connected in series, and the second switching device group includes a third transistor and a fourth transistor connected in series.

[0008] Optionally, the freewheeling circuit includes an input port, and the freewheeling circuit includes two diodes, the two diodes are connected in series in the same direction, and the two endpoints formed after the series connection serve as two DC ports of the freewheeling circuit respectively, and the node between the two diodes serves as an input port of the freewheeling circuit, and is coupled to the node between the first switching device group and the second switching device group of the voltage regulating circuit.

[0009] Optionally, the freewheeling circuit includes two input ports, and the freewheeling circuit includes two diodes, wherein the cathode of one diode is coupled to the positive pole of the DC port of the inverter circuit, and the anode of the other diode is coupled to the negative pole of the DC port of the inverter circuit, and the anode of the one diode and the cathode of the other diode serve as the two input ports of the freewheeling circuit, and are respectively coupled to the intermediate nodes of the two transistors in the first switching device group and the intermediate nodes of the two transistors connected in series in the second switching device group.

[0010] Optionally, an AC port of the inverter circuit is coupled to the output end of the input circuit, or the output end of the voltage regulating circuit, or the output end of the power supply voltage regulating device based on the inverter circuit, and another AC port of the inverter circuit is coupled to the other end of the input AC power or the neutral line. The inverter circuit includes an inverter bridge arm, two DC support capacitors, and a first inductor, wherein the inverter bridge arm is composed of an upper and a lower transistor connected in series, and the positive and negative poles of the inverter bridge arm constitute the two DC ports of the inverter circuit; the two DC support capacitors are connected in series, and the two endpoints formed by the series connection are respectively coupled to the positive and negative poles of the inverter bridge arm, and the node between the two DC support capacitors serves as another AC port of the inverter circuit; the two DC support capacitors are used to stabilize the DC voltage of the inverter circuit; one end of the first inductor is coupled to the midpoint of the inverter bridge arm, and the other end of the first inductor serves as an AC port of the inverter circuit, and the first inductor is used to filter out high-frequency pulsating current of the output current of the inverter circuit.

[0011] Optionally, an AC port of the inverter circuit is coupled to the output end of the input circuit, or the output end of the voltage regulating circuit, or the output end of the power supply voltage regulating device based on the inverter circuit, and another AC port of the inverter circuit is coupled to the other end of the input AC power or the neutral line. The inverter circuit includes two inverter bridge arms, a DC support capacitor, and a second inductor, wherein each inverter bridge arm is composed of an upper and a lower transistor connected in series, the positive poles of the two inverter bridge arms are coupled to form a DC port of the inverter circuit, and the negative poles of the two inverter bridge arms are coupled to form another DC port of the inverter circuit; the DC support capacitor is connected in parallel with the two inverter bridge arms; one end of the second inductor is coupled to the midpoint of one inverter bridge arm, the other end of the second inductor serves as an AC port of the inverter circuit, and the midpoint of the other inverter bridge arm serves as another AC port of the inverter circuit.

[0012] Optionally, the input circuit includes a first capacitor, wherein one end of the first capacitor is coupled to the input end of the input circuit and serves as the output end of the input circuit, and the other end of the first capacitor serves as the common end of the input circuit and is coupled to the other end of the input alternating current or the neutral line.

[0013] Optionally, the input circuit includes a third inductor and a second capacitor, wherein one end of the third inductor is coupled to the input end of the input circuit, and the other end of the third inductor is coupled to one end of the second capacitor and serves as the output end of the input circuit; the other end of the second capacitor serves as the common end of the input circuit and is coupled to the other end of the input alternating current or the neutral line.

[0014] Optionally, the device also includes an output circuit, which includes a fourth inductor and a third capacitor, wherein one end of the fourth inductor is coupled to the output end of the voltage regulation circuit, and the other end of the fourth inductor is coupled to one end of the third capacitor and serves as an output port of the power supply voltage regulation device based on the inverter circuit; the other end of the third capacitor is coupled to the other end of the input alternating current or the neutral line; the fourth inductor and the third capacitor are used to eliminate the voltage ripple and current ripple at the output end of the voltage regulation circuit, and are coupled to the load.

[0015] According to a second aspect of an embodiment of the present application, a power supply voltage regulation device based on an inverter circuit is provided, the device comprising three input circuits, three voltage regulating circuits, an inverter circuit, and a freewheeling circuit, each input circuit comprising an input terminal, an output terminal, and a common terminal, the input terminal being coupled to one phase of a three-phase input alternating current, the common terminal being coupled to a neutral line of the three-phase input alternating current, the three input circuits filtering the three-phase input alternating current and outputting it through the output terminals of the three input circuits; each voltage regulating circuit comprising a first switching device group and a second switching device group, the first switching device group and the second switching device group being coupled in series to form a series circuit, one end point of the series circuit being coupled to the output terminal of an input circuit, the other end point of the series circuit being coupled to the neutral line of the three-phase input alternating current, the midpoint of the series circuit serving as the output terminal of the voltage regulating circuit; each voltage regulating circuit being connected to a first switching device group by connecting the first switching device group and the second switching device group to the neutral line of the three-phase input alternating current The modulation of the working states of the switching devices in the device group and the second switching device group realizes the regulation of the three-phase input AC power, and outputs the three-phase voltage through the output ends of the three voltage regulating circuits to supply the load; the inverter circuit includes three AC ports and two DC ports, and the two DC ports of the inverter circuit are respectively coupled to the two DC ports of the freewheeling circuit. The inverter circuit is configured to regulate the DC voltage input to the inverter circuit, regulate the three-phase input AC power or the reactive current and harmonic current at the output end of the power supply voltage regulation device; the freewheeling circuit includes an input port and two DC ports, and the input port of the freewheeling circuit is respectively coupled to the three voltage regulating circuits, and the two DC ports of the freewheeling circuit are coupled to the two DC ports of the inverter circuit. The freewheeling circuit is configured to form a freewheeling path with the three voltage regulating circuits and the inverter circuit to absorb the overvoltage and peak voltage generated by the three voltage regulating circuits.

[0016] Optionally, the first switching device group includes a first transistor and a second transistor connected in series, and the second switching device group includes a third transistor and a fourth transistor connected in series.

[0017] Optionally, the freewheeling circuit includes three input ports, and the freewheeling circuit includes three groups of diodes connected in series in the same direction, each group of diodes connected in series in the same direction forms two endpoints, the first endpoint of each group of diodes connected in series in the same direction is coupled as a DC port of the freewheeling circuit, and the second endpoint of each group of diodes connected in series in the same direction is coupled as another DC port of the freewheeling circuit; the three intermediate nodes of the three groups of diodes connected in series in the same direction, constitute the three input ports of the freewheeling circuit, and are respectively coupled to the nodes in the middle of the first switching device group and the second switching device group of the three voltage regulating circuits.

[0018] Optionally, the freewheeling circuit includes six input ports, and the freewheeling circuit includes a first group of diodes and a second group of diodes. The first group of diodes includes three diodes, wherein the cathodes of the three diodes are coupled to each other and to the positive pole of the DC port of the inverter circuit, and the anodes of the three diodes constitute the three input ports of the freewheeling circuit, and are respectively coupled to the intermediate nodes of the two transistors connected in series of the first switching device group or the second switching device group of the three voltage regulating circuits; the second group of diodes includes another three diodes, wherein the anodes of the other three diodes are coupled to each other and to the negative pole of the DC port of the inverter circuit, and the cathodes of the other three diodes constitute the other three input ports of the freewheeling circuit, and are respectively coupled to the intermediate nodes of the two transistors connected in series of the second switching device group or the first switching device group of the three voltage regulating circuits.

[0019] Optionally, the three AC ports of the inverter circuit are respectively coupled to the output ends of the three input circuits, or the output ends of the three voltage regulating circuits, or the output ends of the power supply voltage regulating device based on the inverter circuit, and the two DC ports of the inverter circuit are respectively coupled to the two DC ports of the freewheeling circuit. The inverter circuit includes three inverter bridge arms, a DC support capacitor, and three inductors, wherein each inverter bridge arm is composed of an upper and a lower transistor connected in series, and the positive poles of the three inverter bridge arms are coupled to form a DC port of the inverter circuit, and the negative poles of the three inverter bridge arms are coupled to form another DC port of the inverter circuit; the DC support capacitor is connected in parallel with the three inverter bridge arms; the three one ends of the three inductors are respectively coupled to the three midpoints of the three inverter bridge arms, and the three other ends of the three inductors serve as the three AC ports of the inverter circuit.

[0020] Optionally, the DC support capacitor of the inverter circuit includes two groups of upper and lower capacitors. The two groups of capacitors are connected in series, and the two endpoints formed by the series connection are coupled with the positive pole and negative pole of the inverter bridge arm respectively. The node between the two groups of capacitors serves as the fourth AC port of the inverter circuit and is coupled with the neutral line of the three-phase input AC power.

[0021] Optionally, the input circuit includes a first capacitor, wherein one end of the first capacitor is coupled to the input end of the input circuit and serves as the output end of the input circuit, and the other end of the first capacitor serves as the common end of the input circuit and is coupled to the neutral line of the three-phase input alternating current.

[0022] Optionally, the device also includes three output circuits, each output circuit includes a fourth inductor and a third capacitor, wherein one end of the fourth inductor is coupled to the output end of the corresponding voltage regulating circuit, and the other end of the fourth inductor is coupled to one end of the third capacitor and simultaneously serves as an output port of the power supply voltage regulating device based on the inverter circuit; the other end of the third capacitor is coupled to the neutral line of the three-phase input alternating current; the fourth inductor and the third capacitor are used to eliminate the voltage ripple and current ripple at the output ends of the three voltage regulating circuits, and are coupled to the load.

[0023] The beneficial technical effects of the embodiments of the present application are:

[0024] The inverter circuit-based power supply voltage regulation device provided in the embodiments of the present application incorporates an inverter circuit and a freewheeling circuit to regulate reactive current and harmonic current in the circuit, as well as the DC voltage input to the inverter circuit and suppress overvoltage absorption. Furthermore, the freewheeling circuit creatively connects the inverter circuit and the voltage regulation circuit, effectively achieving voltage regulation and stabilization based on the inverter circuit. The embodiments of the present application have a simple circuit structure, reduce equipment costs, effectively ensure grid voltage stability, and have the advantages of fast response, low cost, simple control, high reliability, easy maintenance, and efficient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the embodiments of the present application or the technical solutions in related technologies, the following will briefly introduce the drawings required for use in the specific implementation methods or related technical descriptions. Obviously, the drawings described below are only some implementation methods of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1-3 These are three schematic structural block diagrams of a power supply voltage regulating device based on an inverter circuit in a single-phase application scenario provided by an embodiment of the present application;

[0027] Figure 4-5 7-8 are four exemplary circuit diagrams of a power supply voltage regulating device based on an inverter circuit in a single-phase application scenario provided by an embodiment of the present application;

[0028] Figure 6 This is an exemplary circuit diagram of an inverter circuit in a single-phase application scenario provided by an embodiment of the present application;

[0029] Figure 9 、 14 These are two schematic structural block diagrams of a power supply voltage regulating device based on an inverter circuit in a three-phase application scenario provided by an embodiment of the present application;

[0030] Figure 10-11 These are two exemplary circuit diagrams of freewheeling circuits in a three-phase application scenario provided by the embodiments of the present application;

[0031] Figure 12-13 These are two exemplary circuit diagrams of inverter circuits in the three-phase application scenario provided in the embodiments of the present application. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the embodiments of the present application.

[0033] It should be noted that the terms "first", "second", etc. in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present application described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] It should be noted that, in the absence of conflict, the implementation methods and features in the embodiments of the present application can be combined with each other. The embodiments of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] The power supply voltage regulation device based on the inverter circuit provided in the embodiment of the present application can be used to provide a stable AC power supply to the load when the grid voltage is unstable or a specific voltage level is required. The quality and stability of the output voltage can be ensured mainly through the organic coordination of the inverter circuit and the voltage regulation circuit.

[0036] like Figure 1-3 As shown, the power supply voltage regulation device 100 based on the inverter circuit provided in the embodiment of the present application includes an input circuit 1, a voltage regulation circuit 2, an inverter circuit 3, and a freewheeling circuit 4.

[0037] The input circuit 1 includes an input terminal 11, an output terminal 12 and a common terminal 13. The input terminal 11 is coupled to one end Ui of the input alternating current, and the common terminal 13 is coupled to the other end of the input alternating current or the neutral line N (the figures in the embodiments of the present application all take the other end as N as an example, and in actual applications, the other end can be other non-zero voltages). The input circuit 1 filters the input alternating current and outputs it through the output terminal 12 of the input circuit 1.

[0038] The voltage regulating circuit 2 includes a first switching device group, a second switching device group ( Figure 1-3 (not shown), the first switching device group and the second switching device group are coupled in series to form a series circuit, one end point 21 of the series circuit is coupled to the output end 12 of the input circuit 1, and the other end point 22 of the series circuit is coupled to the other end of the input AC power or the neutral line N. The midpoint of the series circuit serves as the output end 23 of the voltage regulating circuit 2; the voltage regulating circuit 2 regulates the input AC power by modulating the operating states of the switching devices in the first switching device group and the second switching device group, and outputs a voltage through the output end 23 of the voltage regulating circuit 2, which also serves as the output end Uo of the power supply voltage regulating device based on the inverter circuit to supply power to the load;

[0039] The inverter circuit 3 includes two AC ports (AC1, AC2) and two DC ports (DC+, DC-). The two DC ports (DC+, DC-) of the inverter circuit 3 are respectively coupled to the two DC ports (DC+, DC-) of the freewheeling circuit 4. The inverter circuit 3 is configured to regulate the reactive current and harmonic current of the input AC power or the output end of the power supply voltage regulating device. Specifically, when the power grid lacks reactive power, the reactive power can be supplemented by outputting reactive current through the inverter circuit 3 to improve the power factor of the power grid. Specifically, the output reactive current can be controlled by PWM regulating the switching operation of the transistors in the inverter circuit 3. In addition, the harmonic current can be suppressed by regulating the inverter circuit 3 to further ensure the stability of the voltage. The inverter circuit 3 can also regulate the DC voltage input to the inverter circuit 3. When the voltage output by the voltage regulating circuit 2 exceeds the preset voltage value (the preset stable voltage value), the inverter circuit 3 can also be equivalent to an absorption circuit to absorb the excess voltage. If one of the AC ports AC1 of the inverter circuit 3 is coupled to the output end 12 (such as the output end 12 of the input circuit 1) of the inverter circuit 3, the voltage of the inverter circuit 3 can be adjusted. Figure 1 As shown), the reactive current and harmonic current of the input AC are regulated; if AC1 is coupled to the output terminal 23 of the voltage regulating circuit 2, or the output terminal Uo of the power supply voltage regulating device based on the inverter circuit (as shown), Figure 2 As shown), the reactive current and harmonic current at the output end of the power supply voltage regulating device are regulated; another AC port AC2 of the inverter circuit 3 is coupled to the other end of the input AC power or the neutral line N. Further, as Figure 3 As shown, one of the AC ports AC1 of the inverter circuit 3 can also be coupled to the input AC power Ui to regulate the reactive current and harmonic current of the input AC power.

[0040] The freewheeling circuit 4 includes an input port 41 and two DC ports (DC+, DC-). The input port 41 of the freewheeling circuit 4 is coupled to the voltage regulating circuit 2, and the two DC ports (DC+, DC-) of the freewheeling circuit 4 are coupled to the two DC ports (DC+, DC-) of the inverter circuit 3. The freewheeling circuit 4 is configured to form a freewheeling path with the voltage regulating circuit 2 and the inverter circuit 3, absorb the overvoltage and peak voltage generated by the voltage regulating circuit 2, and thereby ensure the stability of the grid voltage.

[0041] Further, such as Figure 4FIG. 1 shows an exemplary circuit diagram of a voltage regulating circuit 2, including a first switching device group 5 and a second switching device group 6. The first switching device group 5 includes a first transistor M1 and a second transistor M2 connected in series, and the second switching device group 6 includes a third transistor M3 and a fourth transistor M4 connected in series. One end of the first switching device group 5 serves as an endpoint 21 of the series circuit, and the other end of the first switching device group 5 is coupled to one end of the second switching device group 6. The other end of the second switching device group 6 serves as another endpoint 22 of the series circuit. The midpoint E of the series circuit serves as the output end 23 of the voltage regulating circuit 2. The first transistor M1 and the second transistor M2 are in opposite directions, and the third transistor M3 and the fourth transistor M4 are also in opposite directions. It should also be noted that, in actual applications, the number of transistors in the first switching device group 5 and the second switching device group 6 can be adaptively adjusted. For example, each transistor (the first to fourth transistors) can be simultaneously replaced with a parallel structure of two or more transistors. It should also be noted that the transistors in the voltage regulating circuit 2 can be one or more power semiconductors such as IGBTs and MOSFETs. By controlling the on / off state of the transistors, PWM modulation can be implemented, thereby achieving the functions of AC voltage regulation and bidirectional energy transfer. For ease of understanding, the complex peripheral circuits of the voltage regulating circuit 2 are not fully illustrated in the present embodiment. Because those skilled in the art, with their ordinary technical knowledge in the field, can implement the technical solutions of the upper and lower bridge arms (i.e., the first switching device group 5 and the second switching device group 6) and their peripheral circuits, solve the corresponding technical problems, and achieve the corresponding technical effects. For example, those skilled in the art can achieve forward and reverse conduction through transistors, and for the purpose of protecting the transistors, connect a freewheeling diode in parallel with each transistor to provide a freewheeling path for current when the transistor is turned off to prevent voltage spikes caused by current flow. The corresponding drive circuit can also be properly configured to receive an external control signal (e.g., a PWM signal, etc.) and control the on / off state of the transistors according to the control signal. Filter inductors can be provided to filter out high-frequency harmonics according to the requirements of different application scenarios to achieve a smoother voltage output.

[0042] Further, such as Figure 4 As shown, the freewheeling circuit 4 includes an input port 41, and the freewheeling circuit 4 includes two diodes (D1, D2). The two diodes are connected in series in the same direction, and the two endpoints formed after the series connection serve as two DC ports (DC+, DC-) of the freewheeling circuit 4 respectively. The node between the two diodes serves as an input port 41 of the freewheeling circuit 4, and is coupled to the node E between the first switching device group 5 and the second switching device group 6 of the voltage regulating circuit 2.

[0043] Further, if Figure 5As shown, a structural example diagram of another freewheeling circuit 4 is shown, wherein the freewheeling circuit 4 includes two input ports 41, and the freewheeling circuit 4 includes two diodes (D1, D2), wherein the cathode of one diode D1 is coupled to the positive pole DC+ of the DC port of the inverter circuit 3, and the anode of the other diode D2 is coupled to the negative pole DC- of the DC port of the inverter circuit 3, and the anode of one diode D1 and the cathode of the other diode D2 serve as the two input ports 41 of the freewheeling circuit 4, which are respectively coupled to the intermediate node F of the two transistors in the first switching device group 5 and the intermediate node G of the two transistors connected in series in the second switching device group 6.

[0044] Further, such as Figure 4 As shown in FIG5 , the inverter circuit 3 includes an inverter bridge arm, two DC support capacitors (Cs), and a first inductor L1, wherein the inverter bridge arm is composed of an upper and lower transistors (M5, M6) connected in series, and the positive and negative electrodes of the inverter bridge arm constitute two DC ports (DC+, DC-) of the inverter circuit 3; the two DC support capacitors (Cs) are connected in series, and the two endpoints formed by the series connection are coupled to the positive and negative electrodes of the inverter bridge arm respectively, and the node between the two DC support capacitors (Cs) serves as another AC port AC2 of the inverter circuit 3; the two DC support capacitors (Cs) are used to stabilize the DC voltage of the inverter circuit 3; one end of the first inductor L1 is coupled to the midpoint of the inverter bridge arm, and the other end of the first inductor L1 serves as an AC port AC1 of the inverter circuit 3, and the first inductor L1 is used to filter out high-frequency pulsating current of the output current of the inverter circuit 3.

[0045] Furthermore, the embodiment of the present application also provides a structural diagram of another inverter circuit 3, such as Figure 6 As shown, the inverter circuit 3 includes two inverter bridge arms (M7, M8) and (M9, M10), a DC support capacitor Cs, and a second inductor L2, wherein each inverter bridge arm is composed of an upper and a lower transistor connected in series, the positive poles of the two inverter bridge arms are coupled to form a DC port DC+ of the inverter circuit 3, and the negative poles of the two inverter bridge arms are coupled to form another DC port DC- of the inverter circuit 3; the DC support capacitor Cs is connected in parallel with the two inverter bridge arms; one end of the second inductor L2 is coupled to the midpoint of one inverter bridge arm, and the other end of the second inductor L2 serves as an AC port AC1 of the inverter circuit 3, and the midpoint of the other inverter bridge arm serves as another AC port AC2 of the inverter circuit 3.

[0046] It should be noted that Figure 4 or Figure 5 The inverter circuit 3 in the figure is a half-bridge inverter structure with low power. Figure 6The inverter circuit 3 is a full-bridge inverter structure with high power, but the functions of the inverter circuit 3 can be achieved by controlling the transistors therein. In practical applications, the specific structure of the inverter circuit 3 can be selected according to the actual power requirements.

[0047] Further, such as Figure 4 As shown in FIG5 , the input circuit 1 includes a first capacitor C1, wherein one end of the first capacitor C1 is coupled to the input end 11 of the input circuit 1 and serves as the output end 12 of the input circuit 1, and the other end of the first capacitor C1 serves as the common end 13 of the input circuit 1 coupled to the other end of the input alternating current or the neutral line N.

[0048] Furthermore, another structural example diagram of the input circuit 1 is provided, such as Figure 7 As shown, the input circuit 1 includes a third inductor L3 and a second capacitor C2, wherein one end of the third inductor L3 is coupled to the input terminal 11 of the input circuit 1, and the other end of the third inductor L3 is coupled to one end of the second capacitor C2 and also serves as the output terminal 12 of the input circuit 1; the other end of the second capacitor C2 serves as the common terminal 13 of the input circuit 1 and is coupled to the other end of the input AC power or the neutral line N. Figure 7 Input circuit 1 in Figure 4 Compared with 5, adding an inductor can further reduce the circuit impedance, reduce the circuit ripple, smooth and remove the clutter, and improve the stability of the grid voltage input.

[0049] Further, such as Figure 8 As shown, the device also includes an output circuit 7, which includes a fourth inductor L4 and a third capacitor C3. One end of the fourth inductor L4 is coupled to the output terminal 23 of the voltage regulator circuit 2, and the other end of the fourth inductor L4 is coupled to one end of the third capacitor C3, serving as an output port Uo of the power supply voltage regulator based on the inverter circuit. The other end of the third capacitor C3 is coupled to the other end of the input AC power supply or the neutral line N. The fourth inductor L4 and the third capacitor C3 are used to eliminate voltage and current ripple at the output terminal 23 of the voltage regulator circuit 2 and are coupled to the load. As an inductor connected to the output terminal Uo, the fourth inductor L4 filters high-frequency components in the voltage and current, eliminates electromagnetic interference, reduces circuit impedance, reduces circuit ripple, smoothes and removes noise, and further stabilizes the voltage.

[0050] It should be noted that, according to the above description, an AC port AC1 of the inverter circuit 3 can be coupled to any one of the output terminal 12 of the input circuit 1, the output terminal 23 of the voltage regulating circuit 2, the output terminal Uo of the power supply voltage regulating device, and the input AC power Ui. Figure 7 The embodiment takes AC1 coupling input AC power as an example. Figure 4-6 Take AC1 coupled to the output terminal 12 of the input circuit 1 as an example. Figure 8 Taking the example of AC1 coupling the output terminal Uo of the power supply voltage regulating device 100 as an example, it can be understood that Figure 4-8 Each figure shows only one way of AC1 coupling. Other coupling methods are not listed one by one. In actual application, please refer to the above Figure 1-3 The structural diagram in is obtained.

[0051] In summary, the inverter circuit-based power supply voltage regulation device 100 provided in the embodiment of the present application, by adding an inverter circuit and a freewheeling circuit, regulates the reactive current and harmonic current in the circuit, adjusts the DC voltage input to the inverter circuit, and suppresses absorption overvoltage through the inverter circuit. Furthermore, the inverter circuit and the voltage regulation circuit are creatively connected organically through the freewheeling circuit, more effectively achieving voltage regulation and stabilization based on the inverter circuit. The embodiment of the present application has a simple circuit structure, reduces equipment costs, effectively ensures the stability of the grid voltage, and has the advantages of fast response, low cost, simple control, high reliability, easy maintenance, and efficient operation.

[0052] The application scenarios of the embodiments of this application include three-phase and single-phase. Three-phase is mostly used in factories and other scenarios, and single-phase is mostly used in residential electricity scenarios, that is, 380V (also written as 0.4kv) and 220V respectively. The electricity usage scenarios can also be verified based on the rated voltage marked on the nameplate of the electrical equipment. Figure 1-8 The embodiment is applied in a single-phase scenario.

[0053] Furthermore, embodiments of the present application also provide a power supply voltage regulator 200 based on an inverter circuit for a three-phase scenario. While the functions and effects of the three-phase scenario are the same as those of the single-phase scenario, some structural modules require adjustments. The following describes the power supply voltage regulator 200 based on an inverter circuit for a three-phase scenario in detail.

[0054] like Figure 9As shown, the power supply voltage regulation device 200 based on the inverter circuit includes three input circuits 1, three voltage regulation circuits 2, an inverter circuit 3, and a freewheeling circuit 4. Each input circuit 1 includes an input terminal 11, an output terminal 12, and a common terminal 13. The input terminal 11 is coupled to one phase (UiA or UiB or UiC) of the three-phase input AC power, and the common terminal 13 is coupled to the neutral line N of the three-phase input AC power. The three input circuits 1 filter the three-phase input AC power (UiA, UiB, UiC, N) and output it through the output terminals 12 of the three input circuits 1. Furthermore, each input circuit 1 includes a first capacitor C1, wherein one end of the first capacitor C1 is coupled to the input terminal 11 of the input circuit 1 and serves as the output terminal 12 of the input circuit 1, and the other end of the first capacitor C1 serves as the common terminal of the input circuit 1 and is coupled to the neutral line N of the three-phase input AC power. In addition, as another input circuit structure, input circuit 1 includes a third inductor L3 and a second capacitor C2. One end of the third inductor L3 is coupled to input terminal 11 of input circuit 1, and the other end of the third inductor L3 is coupled to one end of the second capacitor C2, which also serves as output terminal 12 of input circuit 1. The other end of the second capacitor C2 serves as a common terminal 13 of input circuit 1 and is coupled to the neutral line. It should be noted that the structure and function of input circuit 1 in the three-phase embodiment are identical to those of input circuit 1 in the aforementioned single-phase embodiment. For details, please refer to the corresponding descriptions and illustrations in the aforementioned embodiments and will not be repeated here.

[0055] Each voltage regulating circuit 2 includes a first switching device group 5, a second switching device group 6 ( Figure 9 (not shown), the first switching device group 5 and the second switching device group 6 are coupled in series to form a series circuit. One terminal 21 of the series circuit is coupled to the output terminal 12 of an input circuit 1, and the other terminal 22 of the series circuit is coupled to the neutral line N of the three-phase input AC power. The midpoint E of the series circuit serves as the output terminal 23 of the voltage regulating circuit. Each voltage regulating circuit 2 regulates the three-phase input AC power by modulating the operating states of the switches in its respective first switching device group 5 and second switching device group 6, and outputs three-phase voltages (UoA, UoB, UoC, N) through the output terminals 23 of the three voltage regulating circuits to supply the load. Furthermore, the first switching device group 5 includes a first transistor M1 and a second transistor M2 connected in series, and the second switching device group 6 includes a third transistor M3 and a fourth transistor M4 connected in series. The structure and function of the voltage regulating circuit 2 in the three-phase embodiment are identical to those in the single-phase embodiment. Please refer to the corresponding descriptions and illustrations in the aforementioned embodiment and will not be repeated here.

[0056] The inverter circuit 3 includes three AC ports (AC1, AC2, AC3) and two DC ports (DC+, DC-). The inverter circuit 3 is configured to regulate the DC voltage input to the inverter circuit 3, and regulate the reactive current and harmonic current of the three-phase input AC power (UiA, UiB, UiC, N) or the output end (UoA, UoB, UoC, N) of the power supply voltage regulation device;

[0057] The freewheeling circuit 4 includes an input port 41 and two DC ports (DC+, DC-). The input port 41 of the freewheeling circuit 4 is coupled to the three voltage regulating circuits 2 respectively, and the two DC ports (DC+, DC-) of the freewheeling circuit 4 are coupled to the two DC ports (DC+, DC-) of the inverter circuit. The freewheeling circuit 4 is configured to form a freewheeling path with the three voltage regulating circuits 2 and the inverter circuit 3 to absorb the overvoltage and spike voltage generated by the three voltage regulating circuits 2.

[0058] Further, such as Figure 10 As shown, the freewheeling circuit 4 includes three input ports 41. The freewheeling circuit 4 includes three groups of diodes connected in series in the same direction in pairs (D1 and D2 are one group, D3 and D4 are one group, and D5 and D6 are one group). Each group of diodes connected in series in the same direction forms two endpoints. The first endpoint of each group of diodes connected in series in the same direction is coupled as a DC port DC+ of the freewheeling circuit 4, and the second endpoint of each group of diodes connected in series in the same direction is coupled as another DC port DC- of the freewheeling circuit 4. The three intermediate nodes (O, P, Q) of the three groups of diodes connected in series in the same direction in pairs constitute the three input ports 41 of the freewheeling circuit 4. The three input ports 41 are respectively coupled to the nodes E between the first switching device group 5 and the second switching device group 6 of each voltage regulating circuit 2.

[0059] like Figure 11As shown, a structural diagram of another freewheeling circuit 4 is provided, including six input ports 41. The freewheeling circuit 4 includes a first group of diodes (D1, D2, D3) and a second group of diodes (D4, D5, D6). The first group of diodes includes three diodes (D1, D2, D3), wherein the cathodes of the three diodes (D1, D2, D3) are coupled to each other and to the positive electrode of the DC port DC+ of the inverter circuit 3, and the anodes of the three diodes (D1, D2, D3) constitute the three input ports 41 of the freewheeling circuit and are respectively connected to the intermediate nodes (F1, F2, F3) of the two transistors connected in series of the first switching device group or the second switching device group of the three voltage regulating circuits 23. or G, i.e., the anodes of D1, D2, and D3 are connected to three F points or three G points respectively); the second group of diodes includes another three diodes (D4, D5, and D6), wherein the anodes of the other three diodes (D4, D5, and D6) are coupled to each other and to the negative electrode DC- of the DC port of the inverter circuit 3, and the cathodes of the other three diodes (D4, D5, and D6) constitute the other three input ports 41 of the freewheeling circuit 4, and are respectively coupled to the intermediate nodes (G or F, i.e., the cathodes of D4, D5, and D6 are connected to three G points or three F points respectively) of the two transistors in series of the second switching device group or the first switching device group of the three voltage regulating circuits 2. It should be noted that Figure 10 and 11 Compared with the two freewheeling circuits 4, Figure 10 The cost is lower, Figure 11 The freewheeling voltage is lower, and in practical applications, different circuit structures can be selected according to actual needs.

[0060] Furthermore, the three AC ports (AC1, AC2, AC3) of the inverter circuit 3 are respectively coupled to the output terminals 12 of the three input circuits 1 (eg Figure 9 As shown), or the output end 23 of the three voltage regulating circuits (refer to Figure 2 As shown in the figure, the coupling methods of AC1, AC2 and AC3 are the same as Figure 2 The connection mode of AC1 is the same as that of AC1 in FIG), or the output terminal of the power supply voltage regulating device based on the inverter circuit (see Figure 2 or Figure 8 As shown in the figure, the coupling methods of AC1, AC2 and AC3 are the same as Figure 2 Or the connection method of AC1 in 8 is the same), such as Figure 9 As shown, the two DC ports (DC+, DC-) of the inverter circuit 3 are respectively coupled to the two DC ports (DC+, DC-) of the freewheeling circuit 4. Figure 12As shown, a structural diagram of an inverter circuit 3 is provided, including three inverter bridge arms (one bridge arm for M5 and M6, one bridge arm for M7 and M8, and one bridge arm for M9 and M10), a DC support capacitor Cs, and three inductors (L5, L6, and L7). Each inverter bridge arm is composed of two upper and lower transistors connected in series, the positive poles of the three inverter bridge arms are coupled to form a DC port DC+ of the inverter circuit 3, and the negative poles of the three inverter bridge arms are coupled to form another DC port DC- of the inverter circuit 3; the DC support capacitor Cs is connected in parallel with the three inverter bridge arms; one end of the three inductors (L5, L6, and L7) is respectively coupled to the three midpoints (X, Y, and Z) of the three inverter bridge arms, and the other ends of the three inductors (L5, L6, and L7) serve as three AC ports (AC1, AC2, and AC3) of the inverter circuit 3. Furthermore, like the inverter circuit 3 in the single-phase embodiment, the three AC ports (AC1, AC2, AC3) of the inverter circuit 3 can also be coupled to the three-phase input AC power (UiA, UiB, UiC). For details, please refer to Figure 3 The connection method of AC1 is shown in FIG.

[0061] Further, such as Figure 13 As shown, the DC support capacitor Cs of the inverter circuit 3 may include two groups of upper and lower capacitors (C4 and C5). The two groups of capacitors (C4 and C5) are connected in series, and the two endpoints formed by the series connection are respectively coupled to the positive electrode DC+ and the negative electrode DC- of the inverter bridge arm. The node T between the two groups of capacitors serves as the fourth AC port AC4 of the inverter circuit and is coupled to the neutral line N of the three-phase input AC power.

[0062] Further, such as Figure 14 As shown, the device also includes three output circuits 7, each including a fourth inductor L4 and a third capacitor C3. One end of the fourth inductor L4 is coupled to the output terminal 23 of each voltage regulating circuit 2, and the other end of the fourth inductor L4 is coupled to one end of the third capacitor C3, simultaneously serving as an output port (UoA, UoB, or UoC) of the inverter-based power supply voltage regulation device. The other end of the third capacitor C3 is coupled to the neutral line N of the three-phase input AC power. The fourth inductor L4 and the third capacitor C3 are used to eliminate voltage and current ripple at the output terminals 23 of the three voltage regulating circuits 2 and are coupled to the load. The structure and function of the output circuit 7 in the three-phase embodiment are identical to those of the output circuit 7 in the single-phase embodiment. Please refer to the corresponding descriptions and illustrations in the aforementioned embodiment and will not be repeated here.

[0063] In summary, the embodiment of the present application stabilizes the grid voltage at a preset voltage value through the coordinated cooperation of multiple functional modules, provides a stable and reliable voltage supply for the load equipment, ensures the normal operation and performance of the load equipment, has strong adaptability and flexibility, and realizes stable regulation and efficient transmission of the grid voltage.

[0064] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features that are included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments. For example, any one of the embodiments claimed in the claims may be used in any combination in the embodiments of this application.

[0066] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0067] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the embodiments of the present application, and are not intended to limit them. Although the embodiments of the present application have been described in detail with reference to the above embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents, and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the specific implementation methods of the embodiments of the present application.

Claims

1. A power supply voltage regulating device based on an inverter circuit, characterized in that: The device includes an input circuit, a voltage regulating circuit, an inverter circuit, and a freewheeling circuit. The input circuit includes an input terminal, an output terminal, and a common terminal. The input terminal is coupled to one terminal of the input AC power, and the common terminal is coupled to the other terminal of the input AC power, or the neutral line. The input circuit filters the input AC power and outputs it through the output terminal of the input circuit. The voltage regulating circuit includes a first switching device group and a second switching device group. The first switching device group and the second switching device group are coupled in series to form a series circuit. One end of the series circuit is coupled to the output end of the input circuit, and the other end of the series circuit is coupled to the other end of the input AC power or a neutral line. The midpoint of the series circuit serves as the output end of the voltage regulating circuit. The voltage regulating circuit regulates the input AC power by modulating the operating states of the switching devices in the first switching device group and the second switching device group. The voltage is output through the output end of the voltage regulating circuit, which also serves as the output end of the power supply voltage regulating device based on the inverter circuit to supply power to the load. The inverter circuit includes two AC ports and two DC ports, the two DC ports of the inverter circuit are respectively coupled to the two DC ports of the freewheeling circuit, and the inverter circuit is configured to regulate the DC voltage input to the inverter circuit, and regulate the reactive current and harmonic current of the input AC power or the output end of the power supply voltage regulating device; The freewheeling circuit includes an input port and two DC ports. The input port of the freewheeling circuit is coupled to the voltage regulating circuit, and the two DC ports of the freewheeling circuit are coupled to the two DC ports of the inverter circuit. The freewheeling circuit is configured to form a freewheeling path with the voltage regulating circuit and the inverter circuit to absorb overvoltage and spike voltage generated by the voltage regulating circuit.

2. The power supply voltage regulating device based on the inverter circuit according to claim 1, characterized in that: The first switching device group of the voltage regulating circuit includes a first transistor and a second transistor connected in series, and the second switching device group includes a third transistor and a fourth transistor connected in series.

3. The power supply voltage regulating device based on the inverter circuit according to claim 1, characterized in that: The freewheeling circuit includes an input port, and the freewheeling circuit includes two diodes. The two diodes are connected in series in the same direction, and the two endpoints formed after the series connection serve as two DC ports of the freewheeling circuit respectively. The node between the two diodes serves as an input port of the freewheeling circuit and is coupled to the node between the first switching device group and the second switching device group of the voltage regulating circuit.

4. The power supply voltage regulating device based on the inverter circuit according to claim 2, characterized in that: The freewheeling circuit includes two input ports, and the freewheeling circuit includes two diodes, wherein the cathode of one diode is coupled to the positive pole of the DC port of the inverter circuit, and the anode of the other diode is coupled to the negative pole of the DC port of the inverter circuit. The anode of the one diode and the cathode of the other diode serve as the two input ports of the freewheeling circuit, and are respectively coupled to the intermediate nodes of the two transistors in the first switching device group and the intermediate nodes of the two transistors connected in series in the second switching device group.

5. The power supply voltage regulating device based on the inverter circuit according to claim 1, characterized in that: One AC port of the inverter circuit is coupled to the output end of the input circuit, or the output end of the voltage regulating circuit, or the output end of the power supply voltage regulating device based on the inverter circuit, and another AC port of the inverter circuit is coupled to the other end of the input AC power or the neutral line. The inverter circuit includes an inverter bridge arm, two DC support capacitors, a first inductor, The inverter bridge arm is composed of an upper transistor and a lower transistor connected in series, and the positive and negative electrodes of the inverter bridge arm constitute the two DC ports of the inverter circuit; The two DC support capacitors are connected in series, and the two endpoints formed by the series connection are respectively coupled to the positive electrode and the negative electrode of the inverter bridge arm, and the node between the two DC support capacitors serves as another AC port of the inverter circuit; the two DC support capacitors are used to stabilize the DC voltage of the inverter circuit; One end of the first inductor is coupled to the midpoint of the inverter bridge arm, and the other end of the first inductor serves as an AC port of the inverter circuit. The first inductor is used to filter out high-frequency pulsating current of the output current of the inverter circuit.

6. The power supply voltage regulating device based on an inverter circuit according to claim 1, characterized in that: One AC port of the inverter circuit is coupled to the output end of the input circuit, or the output end of the voltage regulating circuit, or the output end of the power supply voltage regulating device based on the inverter circuit. Another AC port of the inverter circuit is coupled to the other end of the input AC power or the neutral line. The inverter circuit includes two inverter bridge arms, a DC support capacitor, a second inductor, Each inverter bridge arm is composed of an upper and a lower transistor connected in series, the positive electrodes of the two inverter bridge arms are coupled to form a DC port of the inverter circuit, and the negative electrodes of the two inverter bridge arms are coupled to form another DC port of the inverter circuit; The DC support capacitor is connected in parallel with the two inverter bridge arms; One end of the second inductor is coupled to the midpoint of one inverter bridge arm, the other end of the second inductor serves as an AC port of the inverter circuit, and the midpoint of the other inverter bridge arm serves as another AC port of the inverter circuit.

7. The power supply voltage regulating device based on an inverter circuit according to claim 1, characterized in that: The input circuit includes a first capacitor, One end of the first capacitor is coupled to the input end of the input circuit and serves as the output end of the input circuit, and the other end of the first capacitor serves as the common end of the input circuit and is coupled to the other end of the input AC power or the neutral line.

8. The power supply voltage regulating device based on an inverter circuit according to claim 1, characterized in that: The input circuit includes a third inductor and a second capacitor, One end of the third inductor is coupled to the input end of the input circuit, and the other end of the third inductor is coupled to one end of the second capacitor and serves as the output end of the input circuit. The other end of the second capacitor serves as a common end of the input circuit and is coupled to the other end of the input AC power or the neutral line.

9. The power supply voltage regulating device based on an inverter circuit according to claim 1, characterized in that: The device further includes an output circuit, wherein the output circuit includes a fourth inductor and a third capacitor. One end of the fourth inductor is coupled to the output end of the voltage regulating circuit, and the other end of the fourth inductor is coupled to one end of the third capacitor and serves as an output port of the power supply voltage regulating device based on the inverter circuit. The other end of the third capacitor is coupled to the other end of the input AC power or the neutral line; The fourth inductor and the third capacitor are used to eliminate voltage ripple and current ripple at the output end of the voltage regulating circuit and are coupled to a load.

10. A power supply voltage regulating device based on an inverter circuit, characterized in that: The device includes three input circuits, three voltage regulating circuits, an inverter circuit, and a freewheeling circuit. Each input circuit includes an input terminal, an output terminal, and a common terminal. The input terminal is coupled to one phase of the three-phase input AC power, and the common terminal is coupled to the neutral line of the three-phase input AC power. The three input circuits filter the three-phase input AC power and output it through the output terminals of the three input circuits. Each voltage regulating circuit includes a first switching device group and a second switching device group. The first switching device group and the second switching device group are coupled in series to form a series circuit. One end of the series circuit is coupled to the output end of an input circuit, and the other end of the series circuit is coupled to the neutral line of the three-phase input AC power. The midpoint of the series circuit serves as the output end of the voltage regulating circuit. Each voltage regulating circuit regulates the three-phase input AC power by modulating the operating states of the switching devices in its respective first switching device group and second switching device group, and outputs a three-phase voltage through the output ends of the three voltage regulating circuits to supply a load. The inverter circuit includes three AC ports and two DC ports, and is configured to regulate the DC voltage input to the inverter circuit, and regulate the reactive current and harmonic current at the output end of the three-phase input AC power or the power supply voltage regulating device; The freewheeling circuit includes an input port and two DC ports. The input port of the freewheeling circuit is coupled to the three voltage regulating circuits respectively, and the two DC ports of the freewheeling circuit are coupled to the two DC ports of the inverter circuit. The freewheeling circuit is configured to form a freewheeling path with the three voltage regulating circuits and the inverter circuit to absorb overvoltage and spike voltage generated by the three voltage regulating circuits.

11. The power supply voltage regulating device based on an inverter circuit according to claim 10, characterized in that: The first switching device group includes a first transistor and a second transistor connected in series, and the second switching device group includes a third transistor and a fourth transistor connected in series.

12. The power supply voltage regulating device based on an inverter circuit according to claim 10, characterized in that: The freewheeling circuit includes three input ports, and the freewheeling circuit includes three groups of diodes connected in series in the same direction. Each group of diodes connected in series in the same direction forms two endpoints, a first endpoint of each group of diodes connected in series in the same direction is coupled to serve as a DC port of the freewheeling circuit, and a second endpoint of each group of diodes connected in series in the same direction is coupled to serve as another DC port of the freewheeling circuit; The three middle nodes of the three groups of diodes connected in series in the same direction in pairs constitute the three input ports of the freewheeling circuit and are respectively coupled to the middle nodes of the first switching device group and the second switching device group of the three voltage regulating circuits.

13. The power supply voltage regulating device based on an inverter circuit according to claim 11, characterized in that: The freewheeling circuit includes six input ports, and the freewheeling circuit includes a first group of diodes and a second group of diodes. The first diode group includes three diodes, wherein cathodes of the three diodes are coupled to each other and to the positive electrode of the DC port of the inverter circuit, and anodes of the three diodes constitute three input ports of the freewheeling circuit and are respectively coupled to the intermediate nodes of the two transistors connected in series of the first switching device group or the second switching device group of the three voltage regulating circuits; The second group of diodes includes three other diodes, wherein the anodes of the other three diodes are coupled to each other and to the negative pole of the DC port of the inverter circuit, and the cathodes of the other three diodes constitute the other three input ports of the freewheeling circuit and are respectively coupled to the intermediate nodes of the two transistors connected in series of the second switching device group or the first switching device group of the three voltage regulating circuits.

14. The power supply voltage regulating device based on an inverter circuit according to claim 10, characterized in that: The three AC ports of the inverter circuit are respectively coupled to the output ends of the three input circuits, or the output ends of the three voltage regulating circuits, or the output end of the power supply voltage regulating device based on the inverter circuit; the two DC ports of the inverter circuit are respectively coupled to the two DC ports of the freewheeling circuit; the inverter circuit includes three inverter bridge arms, a DC support capacitor, and three inductors. Each inverter bridge arm is composed of an upper and a lower transistor connected in series, the positive electrodes of the three inverter bridge arms are coupled to form a DC port of the inverter circuit, and the negative electrodes of the three inverter bridge arms are coupled to form another DC port of the inverter circuit; The DC support capacitor is connected in parallel with the three inverter bridge arms; The three one ends of the three inductors are respectively coupled to the three midpoints of the three inverter bridge arms, and the three other ends of the three inductors serve as three AC ports of the inverter circuit.

15. The power supply voltage regulating device based on an inverter circuit according to claim 14, characterized in that: The DC support capacitor of the inverter circuit includes two groups of upper and lower capacitors. The two groups of capacitors are connected in series, and the two endpoints formed by the series connection are coupled to the positive and negative poles of the inverter bridge arm respectively. The node between the two groups of capacitors serves as the fourth AC port of the inverter circuit and is coupled to the neutral line of the three-phase input AC power.

16. The power supply voltage regulating device based on an inverter circuit according to claim 10, characterized in that: The input circuit includes a first capacitor, One end of the first capacitor is coupled to the input end of the input circuit and serves as the output end of the input circuit, and the other end of the first capacitor serves as the common end of the input circuit and is coupled to the neutral line of the three-phase input AC power.

17. The power supply voltage regulating device based on an inverter circuit according to claim 10, characterized in that: The device further comprises three output circuits, each output circuit comprising a fourth inductor, a third capacitor, One end of the fourth inductor is coupled to the output end of the corresponding voltage regulating circuit, and the other end of the fourth inductor is coupled to one end of the third capacitor and serves as an output port of the power supply voltage regulating device based on the inverter circuit; The other end of the third capacitor is coupled to the neutral line of the three-phase input alternating current; The fourth inductor and the third capacitor are used to eliminate voltage ripples and current ripples at the output ends of the three voltage regulating circuits, and are coupled to a load.

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