Boost inverter system

Abstract

The invention discloses a boost inverter system, which relates to the field of photovoltaic power generation and comprises an IGBT (Insulated Gate Bipolar Translator) rectifying circuit, a first capacitor, a second capacitor, a Boost circuit, a third capacitor, an IGBT inverter circuit, a power supply circuit, a Boost driving circuit and an IGBT inverter driving circuit, the voltage input end of the power supply circuit is connected with the output end of the booster circuit; an inversion upper bridge driving voltage output end of the power supply circuit is connected with an upper bridge power supply input end of the inversion driving circuit; an inversion lower bridge-BOOST driving voltage output end of the power supply circuit is connected with a lower bridge power supply input end of the inversion driving circuit and a power supply input end of the Boost driving circuit; a driving signal output end of the inverter driving circuit is connected with a driving signal input end of the inverter circuit; and the driving signal output end of the Boost driving circuit is connected with the driving signal input end of the Boost circuit. The working stability of the inverter circuit is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a boost inverter system. Background Art

[0002] Solar photovoltaic power generation will occupy a significant position in global energy consumption in the 21st century, not only replacing some conventional energy sources but also becoming the majority of the world's energy supply. It is projected that by 2030, renewable energy will account for over 30% of the total energy mix, while solar photovoltaic power generation will account for over 10% of the world's total electricity supply. By 2040, renewable energy will account for over 50% of total energy consumption, and solar photovoltaic power generation will account for over 20% of total electricity. By the end of the 21st century, renewable energy will account for over 80% of the energy mix, and solar power generation for over 60%. These figures clearly demonstrate the promising development prospects of the solar photovoltaic industry and its strategic importance in the energy sector. Amidst the current shortage of oil, carbon, and other energy sources, countries are accelerating the development of photovoltaic power. In the context of developing a low-carbon economy, governments are increasingly recognizing photovoltaic power generation.

[0003] In desert areas or other sparsely populated areas, photovoltaic power generation and energy storage are used to power inverter systems used in various power-consuming fields (such as water pumps, grinders, etc.). However, due to differences in the combination of solar photovoltaic panels and different intensities of sunlight, the input voltage range of the inverter (or inverter circuit) is too large (ranging from 200 to 700 VDC), resulting in unstable inverter operation. Summary of the Invention

[0004] The purpose of this application is to provide a boost inverter system to solve the problem of unstable operation of the inverter circuit described in the background art.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] The present application provides a boost inverter system, comprising: an IGBT rectifier circuit, a Boost boost circuit, an IGBT inverter circuit, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a power supply circuit, a Boost drive circuit, and an IGBT inverter drive circuit;

[0007] The IGBT rectifier circuit, the first capacitor, the second capacitor, the Boost circuit, the third capacitor, the fourth capacitor, and the IGBT inverter circuit are connected in parallel in sequence;

[0008] The voltage input end of the power supply circuit is connected to the output end of the Boost boost circuit; the inverter upper bridge drive voltage output end of the power supply circuit is connected to the upper bridge power input end of the IGBT inverter drive circuit; the inverter lower bridge-BOOST drive voltage input end of the power supply circuit is connected to the lower bridge power input end of the IGBT inverter drive circuit and the power input end of the Boost drive circuit;

[0009] The drive signal output terminal of the IGBT inverter drive circuit is connected to the drive signal input terminal of the IGBT inverter circuit;

[0010] The driving signal output terminal of the Boost driving circuit is connected to the driving signal input terminal of the Boost voltage-increasing circuit.

[0011] Optionally, the IGBT rectifier circuit includes: a first rectifier branch, a second rectifier branch, and a third rectifier branch connected in parallel; the first rectifier branch includes a first diode and a second diode connected in series, and the connection direction is consistent; the first diode and the third rectifier branch are connected in parallel; Second diode A first power input port is provided between the two rectifier branches; the two rectifier branches include a third diode and a fourth diode connected in series, and the connection directions are consistent; a second power input port is provided between the third diode and the fourth diode; the three rectifier branches include a fifth diode and a sixth diode connected in series, and the connection directions are consistent; a third power input port is provided between the fifth diode and the sixth diode.

[0012] Optionally, the Boost circuit includes: a first boost circuit and a second boost circuit connected in parallel, the first boost circuit includes a first inductor and a seventh diode, one end of the first inductor is connected to the cathode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the seventh diode, and the anode of the seventh diode is connected to the first input terminal of the IGBT inverter circuit; the second boost circuit includes a second inductor and an eighth diode, one end of the second inductor is connected to the anode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the eighth diode, and the anode of the eighth diode is connected to the first input terminal of the IGBT inverter circuit;

[0013] The Boost boost circuit also includes a seventh power tube, an eighth power tube and a resistor. The drain of the seventh power tube is connected between the first inductor and the seventh diode, the source is connected to one end of the resistor, and the gate is the first Boost drive signal input end: the drain of the eighth power tube is connected between the second inductor and the eighth diode, the source end is connected to one end of the resistor, and the gate is the second Boost drive signal input end; the other end of the resistor is connected to the positive electrode of the diode included in the IGBT rectifier circuit.

[0014] Optionally, the Boost drive circuit has two optocoupler isolation drives with the same configuration; for each optocoupler isolation drive, an original Boost drive signal receiving end and an amplified Boost drive signal output end are provided, the original Boost drive signal receiving end is connected to the control chip of the Boost boost circuit, and the amplified Boost drive signal output end is connected to the gate of the power tube of the Boost boost circuit.

[0015] Optionally, the boost inverter system further includes a Boost control chip, and the Boost control chip is signal-connected to the Boost drive circuit.

[0016] Optionally, the IGBT inverter circuit includes: a first inverter branch, a second inverter branch and a third inverter branch connected in parallel; each inverter branch includes two power switching tubes connected in series, and the emitter of one power switching tube is connected to the collector of the other power switching tube, and the base is connected to the output end of the amplified inverter drive signal of the IGBT inverter drive circuit.

[0017] Optionally, the IGBT inverter circuit includes a U-phase output, a V-phase output and a W-phase output, which are respectively denoted as U_out, V_out and W_out;

[0018] The power supply circuit includes a transformer, the input end of the transformer is connected to the output end of the Boost boost circuit, and is used to provide a working power supply for the transformer; the transformer is used to generate inverter drive voltages U_PH, V_PH, W_PH and PL, wherein the reference ground of U_PH is shared with the U-phase output of the IGBT inverter circuit, and is used to drive the upper bridge power device of the U phase of the inverter circuit; the reference ground of V_PH is shared with the V-phase output, and is used to drive the upper bridge power device of the V phase of the inverter circuit; the reference ground of W_PH is shared with the W-phase output, and is used to drive the upper bridge power device of the W phase of the inverter circuit. PL is used to drive the three-phase lower bridge power device of the inverter circuit, and PL is also connected to the power device in the Boost drive circuit to provide power for its drive.

[0019] Optionally, the IGBT inverter drive circuit is a 6-way optocoupler isolation drive, the primary sides of the 6 optocouplers share a common ground with the DSP and receive control signals from the DSP. On the secondary side, the three optocouplers that control the lower bridge power devices of the inverter circuit are powered by PL, and the remaining three are powered by corresponding phase drive voltages.

[0020] Optionally, the boost inverter system further includes a DSP, which is signal-connected to the IGBT inverter drive circuit to provide a drive signal for the IGBT inverter drive circuit.

[0021] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0022] The boost inverter system provided by the embodiment of the present application integrates a boost circuit between the IGBT rectifier circuit and the IGBT inverter circuit. The boost circuit boosts the power source rectified by the IGBT rectifier circuit to a substantially constant high voltage, thereby obtaining a stable high voltage to provide a stable voltage input for the IGBT inverter circuit. The boosted voltage is then input to the IGBT inverter circuit, causing the IGBT inverter circuit to invert the input voltage. Furthermore, the boost drive circuit and the IGBT inverter drive circuit share a power supply circuit, which is inherent to the IGBT inverter drive circuit. Therefore, no new power supply circuit is required due to the addition of the boost circuit and the boost drive circuit. In contrast, the existing boost circuit has an internal power supply circuit, meaning that the existing boost inverter system includes two power supply circuits. Therefore, the present application reduces the use of power supply circuits, which not only reduces costs but also reduces the overall size of the boost inverter system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a logic diagram of a boost inverter system in one embodiment of the present application;

[0025] Figure 2 A circuit diagram of a boost inverter system provided in one embodiment of the present application;

[0026] Figure 3 A schematic diagram of an IGBT rectifier circuit provided in one embodiment of the present application;

[0027] Figure 4 A schematic diagram of a Boost circuit provided in another embodiment of the present application;

[0028] Figure 5 A schematic diagram of a Boost drive circuit provided in one embodiment of the present application;

[0029] Figure 6 A schematic diagram of an IGBT inverter circuit provided in another embodiment of the present application;

[0030] Figure 7 A schematic diagram of a power supply circuit provided in one embodiment of the present application;

[0031] Figure 8 A schematic diagram of an IGBT inverter circuit provided in another embodiment of the present application.

[0032] In the picture:

[0033] First diode D1; second diode D2; third diode D3; fourth diode D4; fifth diode D5; sixth diode D6; seventh diode D7; eighth diode D8; first inductor L1; second inductor L2; resistor R; first capacitor C1; second capacitor C2; third capacitor C3; fourth capacitor C4; first power tube Q1; second power tube Q2; third power tube Q3; fourth power tube Q4; fifth power tube Q5; sixth power tube Q6; seventh power tube Q7; eighth power tube Q8. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0036] This application provides a boost inverter system, see Figure 1 and Figure 2 As shown, the boost inverter system includes: an IGBT rectifier circuit, a Boost boost circuit, an IGBT inverter circuit, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a power supply circuit, a Boost drive circuit and an IGBT inverter drive circuit.

[0037] The IGBT rectifier circuit, the first capacitor, the second capacitor, the Boost circuit, the third capacitor, the fourth capacitor, and the IGBT inverter circuit are connected in parallel in sequence;

[0038] The voltage input end of the power supply circuit is connected to the output end of the Boost boost circuit; the inverter upper bridge drive voltage output end of the power supply circuit is connected to the upper bridge power input end of the IGBT inverter drive circuit; the inverter lower bridge-BOOST drive voltage input end of the power supply circuit is connected to the lower bridge power input end of the IGBT inverter drive circuit and the power input end of the Boost drive circuit;

[0039] The drive signal output terminal of the IGBT inverter drive circuit is connected to the drive signal input terminal of the IGBT inverter circuit;

[0040] The driving signal output terminal of the Boost driving circuit is connected to the driving signal input terminal of the Boost voltage-increasing circuit.

[0041] Among them, the IGBT rectifier circuit and the IGBT inverter circuit can be collectively referred to as an IGBT circuit.

[0042] Among them, the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are all 200uF / 1000V and are used for filtering.

[0043] In addition, the power supply circuit is an inherent power supply circuit of the IGBT inverter drive circuit, so that no new power supply circuit is added due to the addition of the Boost circuit and the Boost drive circuit, thereby saving costs and reducing volume.

[0044] The working process of the boost inverter system is as follows:

[0045] When current (either AC or DC) is input to the input end of the IGBT rectifier circuit, the IGBT rectifier circuit rectifies the input current to convert it into DC.

[0046] The output current of the IGBT rectifier circuit charges the first capacitor and the second capacitor. At this time, the voltage across the first capacitor and the second capacitor is recorded as U1;

[0047] When the first capacitor and the second capacitor are fully charged, the output current of the IGBT rectifier circuit is also transmitted to the Boost circuit, which boosts the voltage and outputs the boosted voltage. At this time, the voltage is suitable for input to the IGBT inverter circuit and is still DC.

[0048] The output of the Boost circuit charges the third capacitor and the fourth capacitor; when charging is completed, the output current of the Boost circuit is also input into the IGBT inverter circuit, so that the IGBT inverter circuit inverts the input current, that is, converts DC power into AC power.

[0049] The boost inverter system provided in the embodiment of the present application integrates a Boost circuit between the IGBT rectifier circuit and the IGBT inverter circuit. The Boost circuit boosts the power source rectified by the IGBT rectifier circuit to a substantially fixed high voltage, thereby obtaining a stable high voltage to provide a stable voltage input for the IGBT inverter circuit. The boosted voltage is then input to the IGBT inverter circuit, allowing the IGBT inverter circuit to invert the input voltage. Furthermore, the Boost drive circuit and the IGBT inverter drive circuit share a power supply circuit, reducing the number of power supply circuits. Conventional Boost circuits, on the other hand, have internal power supply circuits, meaning that conventional boost inverter systems include two power supply circuits. Therefore, the present application reduces the number of power supply circuits, which not only reduces costs but also reduces the overall size of the boost inverter system.

[0050] Alternatively, see Figure 3 In another exemplary embodiment of the present application, the IGBT rectifier circuit includes: a first rectifier branch, a second rectifier branch, and a third rectifier branch connected in parallel with each other; the first rectifier branch includes a first diode and a second diode connected in series with each other, and the connection direction is consistent; a first power input port is provided between the first diode and the second diode; the second rectifier branch includes a third diode and a fourth diode connected in series with each other, and the connection direction is consistent; a second power input port is provided between the third diode and the fourth diode; the third rectifier branch includes a fifth diode and a sixth diode connected in series with each other, and the connection direction is consistent; a third power input port is provided between the fifth diode and the sixth diode.

[0051] Among them, the consistent connection direction can be understood as: the cathode of the second diode is connected to the anode of the first diode, the cathode of the fourth diode is connected to the anode of the third diode, the cathode of the sixth diode is connected to the anode of the fifth diode, and the cathodes of the first, third and fifth diodes are connected, and the anodes of the second, fourth and sixth diodes are connected.

[0052] During operation, the external input voltage is connected to the first power input port A, the second power input port B, and the third power input port C. For example, the voltage input from ports A and C is used as an example. The external power input ports A and C are connected to the pins of the IGBT rectifier circuit (GD25PJX120L3S) through internal circuits. If the input voltage of ports A and C is single-phase AC, the voltage is charged to the first capacitor C1 and the second capacitor C2 of the filter capacitor through D1, D6, and D5, D2. If the input of ports A and C is DC, the first capacitor C1 and the second capacitor C2 of the filter capacitor are charged through one of the two branches, D1, D6 or D5, D2, according to the positive and negative of A and C respectively. After passing through C1 and C2, the voltage U1 is generated.

[0053] Among them, the model of the IGBT rectifier circuit is GD25PJX120L3S, and its internal rectifier diodes D1, D2, D3, D4, D5, and D6 are all diodes with a withstand voltage of 1600V and a rated current of 25A.

[0054] Alternatively, see Figure 4 In another exemplary embodiment of the present application, the Boost circuit includes: a first boost circuit and a second boost circuit connected in parallel, the first boost circuit includes a first inductor and a seventh diode, and one end of the first inductor is connected to the cathode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the seventh diode, and the anode of the seventh diode is connected to the first input terminal of the IGBT inverter circuit; the second boost circuit includes a second inductor and an eighth diode, and one end of the second inductor is connected to the anode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the eighth diode, and the anode of the eighth diode is connected to the first input terminal of the IGBT inverter circuit.

[0055] The Boost boost circuit also includes a seventh power tube, an eighth power tube and a resistor. The drain of the seventh power tube is connected between the first inductor and the seventh diode, the source is connected to one end of the resistor, and the gate is the first Boost drive signal input end: the drain of the eighth power tube is connected between the second inductor and the eighth diode, the source end is connected to one end of the resistor, and the gate is the second Boost drive signal input end; the other end of the resistor is connected to the positive electrode of the diode included in the IGBT rectifier circuit.

[0056] like Figure 4 It can be seen that the two Boost driving signal input terminals are Boost1 and Boost2 respectively.

[0057] Alternatively, see Figure 5In another exemplary embodiment of the present application, the boost inverter system further includes a Boost drive circuit, which has two optocoupler isolation drives with the same configuration; for each optocoupler isolation drive, an original Boost drive signal receiving end and an amplified Boost drive signal output end are provided, the original Boost drive signal receiving end is connected to the control chip of the Boost boost circuit, and the amplified Boost drive signal output end is connected to the gate of the power tube of the Boost boost circuit.

[0058] The optocoupler is used to amplify the original Boost drive signal to obtain an amplified Boost drive signal. Furthermore, each optocoupler adopts ACPL-W314-500E.

[0059] The original Boost driving signals are recorded as BG1 and BG2.

[0060] Optionally, in another exemplary embodiment of the present application, the boost inverter system further includes a Boost control chip, which is signal-connected to the Boost drive circuit, thereby inputting an original Boost drive signal to the Boost drive circuit.

[0061] The boost control chip uses the LM5030, which can output two control signals with a built-in dead zone and a duty cycle of up to 50%. This chip is also powered by the boost drive voltage input terminal of the power circuit's inverter lower bridge. A 20Ω resistor connected in series in the circuit serves to limit the voltage. The control signal generated by the boost control chip is output to the boost drive circuit, which, after optical coupling isolation, generates a drive signal capable of driving the power device (HCCW120R080H1) in the boost circuit.

[0062] Furthermore, the boost circuit boosts U1 via two boost circuits. The inductor (first and second inductors) in each circuit has a rating of 800uH / 20A; the diodes (seventh and eighth diodes) have a rating of 1200V / 20A (G5S12010BM); the seventh and eighth power transistors are MOSFETs with a rating of 1200V / 20A (HCCW120R080H1); and the LM5030 controls the switching duty cycle based on the current-reducing resistor R. U1 is interleavedly boosted by the boost circuits, then filtered by C3 and C4 to form a stable voltage, U2. U2 can be used for DC-AC conversion in the IGBT inverter circuit.

[0063] The primary side of the optocoupler shares a common ground with the LM5030 and is driven by the original drive signal from the LM5030. The secondary side is powered by PL and generates a control signal that can drive the Boost power switch tube (HCCW120R080H1) based on the primary side signal.

[0064] The first inductor L1 and the second inductor L2 are 800uH / 20A.

[0065] Among them, the rectifier diodes D7 and D8 are 1200V / 20A SIC diodes, model G5S12010BM;

[0066] Among them, the power tubes (switching tubes) Q1 and Q2 are 1200V / 20A SIC MOSFETs, model HCCW120R080H1.

[0067] In addition, the BOOST boost circuit uses related chips to implement a dual-path interleaved working mode, which can reduce the single-path current, thereby reducing the BOOST switching loss and improving the boost efficiency.

[0068] In this application, the power supply circuit of the BOOST boost circuit and the power supply circuit of the BOOST drive circuit both use the power supply circuit in the original boost inverter system, which can effectively save electronic devices in the BOOST boost circuit, reduce functional circuits (such as the onboard power supply for power supply), and reduce system costs.

[0069] The BOOST circuit also utilizes a dual-path interleaved boost design, which increases the overall switching frequency, reduces losses in a single path, and reduces the size of the inductor, further improving the efficiency and reducing the size of the BOOST circuit. These innovations effectively address the issues of unstable IGBT inverter circuits in photovoltaic and single-phase power supply applications, as well as the high cost and bulk of existing boost inverter systems.

[0070] Alternatively, see Figure 6 In another exemplary embodiment of the present application, the IGBT inverter circuit includes: a first inverter branch, a second inverter branch, and a third inverter branch connected in parallel with each other; each inverter branch includes two power switching tubes connected in series, and the emitter of one power switching tube is connected to the collector of the other power switching tube, and the base is connected to the output end of the amplified inverter drive signal of the IGBT inverter drive circuit.

[0071] The input voltage of the IGBT inverter circuit is U2 after being boosted by the Boost circuit. This voltage is converted into the required AC power by the six power switch tubes (model GD25PJX120L3S) in the inverter circuit to complete the DC-AC conversion.

[0072] Furthermore, the six power switch tubes are respectively recorded as a first power switch tube Q1, a second power switch tube Q2, a third power switch tube Q3, a fourth power switch tube Q4, a fifth power switch tube Q5 and a sixth power switch tube Q6.

[0073] Alternatively, see Figure 7 In another exemplary embodiment of the present application, the IGBT inverter circuit includes a U-phase output, a V-phase output and a W-phase output, which are respectively denoted as U_out, V_out and W_out.

[0074] The power supply circuit includes a transformer, the input end of the transformer is connected to the output end of the Boost boost circuit, and is used to provide a working power supply for the transformer; the transformer is used to generate inverter drive voltages U_PH, V_PH, W_PH and PL, wherein the reference ground of U_PH is shared with the U-phase output of the IGBT inverter circuit, and is used to drive the upper bridge power device of the U phase of the inverter circuit; the reference ground of V_PH is shared with the V-phase output, and is used to drive the upper bridge power device of the V phase of the inverter circuit; the reference ground of W_PH is shared with the W-phase output, and is used to drive the upper bridge power device of the W phase of the inverter circuit. PL is used to drive the three-phase lower bridge power device of the inverter circuit. PL is also connected to the power device (optocoupler) in the Boost drive circuit to provide power for its drive.

[0075] The primary side of the transformer draws power from U2, and before the Boost circuit operates, U2 = U1. The transformer circuit generates inverter drive voltages U_PH, V_PH, W_PH, and PL. U_PH's reference ground is shared with the U-phase output, providing power for the inverter's U-phase upper bridge power device. V_PH's reference ground is shared with the V-phase output, providing power for the inverter's V-phase upper bridge power device. W_PH's reference ground is shared with the W-phase output, providing power for the inverter's W-phase upper bridge power device. PL provides power for the inverter's three-phase lower bridge power device and the power device (HCCW120R080H1) in the Boost circuit.

[0076] The main control chip of the power circuit is UC2845.

[0077] When the voltage of U2 is insufficient, the Boost driver circuit controls the Boost circuit to operate, thereby boosting the voltage of U1. When the voltage of U2 is sufficient, for example, when the external power supply inputs three-phase AC power, the voltage of U2 is sufficient, and the Boost driver circuit controls the Boost circuit to stop operating.

[0078] Alternatively, see Figure 8In another exemplary embodiment of the present application, the boost inverter system further includes an IGBT inverter drive circuit, which is driven by a 6-way optocoupler isolation circuit. The primary sides of these 6 optocouplers share a common ground with the DSP and receive control signals from the DSP. On the secondary side, the three optocouplers that control the lower bridge power devices of the inverter circuit are powered by PL, and the remaining three are powered by corresponding phase drive voltages.

[0079] Among them, the optocoupler model is TLP5701.

[0080] Among them, the IGBT inverter drive circuit is provided with a signal input terminal and a signal output terminal; among them, the signal input terminal is connected to the DSP, used to receive the original drive signal sent by the DSP, and is amplified by the optocoupler. The amplified signal is recorded as the amplified inverter drive signal and is sent to the IGBT inverter drive circuit by the signal output terminal.

[0081] Among them, see Figure 8 The signal input terminals include E+, E-, F+, F-, G+, G-, and the signal output terminals include UH, UL, VH, VL, WH, WL.

[0082] Optionally, the main control chip of the power supply circuit is UC2845, and the driving signal output terminal of the main control chip is connected to the driving signal input terminal of the power supply circuit to control the working state of the power supply circuit.

[0083] The model of the power device in the Boost circuit is HCCW120R080H1, for example, SIC MOSFET (silicon carbide MOSFET).

[0084] Optionally, in another exemplary embodiment of the present application, the boost inverter system further includes a DSP, and the DSP is signal-connected to the IGBT inverter drive circuit to provide a drive signal for the IGBT inverter drive circuit.

[0085] The boost inverter system provided in this application can boost the voltage of photovoltaic panels with different voltage combinations to a higher voltage platform (such as 540VDC), thereby providing power input to the inverter input terminal, thereby achieving a more efficient and stable power supply voltage for DC / AC conversion for the IGBT inverter circuit (or inverter). At the same time, the boost circuit and the inverter circuit can be integrated to increase power density. The same power supply winding can be used to power the boost circuit and the inverter circuit simultaneously, which can further reduce circuit space.

[0086] This circuit power supply is based on the original inverter (DC / AC), sharing most of the power devices to achieve the function of boosting the low voltage platform to the high voltage platform, and then performing DC / AC conversion. It can also boost 220VAC single-phase electricity to 540VDC to power the inverter, achieving more efficient conversion.

[0087] The purpose of this application is to address the following existing problems: 1. The output voltage range of solar photovoltaic panels varies greatly due to factors such as the influence of sunlight or uncertainty in power generation efficiency, resulting in poor working stability of the IGBT inverter circuit; 2. When the current 220V single-phase AC input voltage is used to power the IGBT inverter circuit, there is insufficient voltage (the voltage range of the single-phase AC input voltage after rectification and filtering is approximately 200VDC to 350VDC), resulting in unstable operation of the inverter; Therefore, this application adds a BOOST boost circuit to the original DC-AC inverter system (including an IGBT rectifier circuit, an IGBT inverter circuit, a power supply circuit, an IGBT inverter drive circuit, and a BOOST drive circuit), and uses the power supply circuit (also the power supply circuit in the original DC-AC system) as the power supply circuit. After the BOOST boost circuit adjusts the input voltage, the input voltage of the final inverter can be stabilized within a voltage range that allows it to operate reliably, thereby allowing the IGBT inverter circuit to operate reliably in the above-mentioned scenarios 1 and 2.

[0088] This application allows external input to be three-phase AC, single-phase AC and DC input, where the DC input range is (200~500VDC) and the AC input is 220VAC. After the external input is rectified by the internal rectifier bridge of the IGBT (GD25PJX120L3S) rectifier circuit, it is filtered by the first capacitor C1 and the second capacitor C2 of the filter capacitor to generate a DC voltage U1. U1 serves as the input voltage of the Boost boost circuit. After being boosted by the Boost boost circuit, it is filtered by the third capacitor C3 and the fourth capacitor C4 of the filter capacitor to generate a stable 540V voltage U2. U2 serves as the input voltage of the IGBT inverter circuit and completes the DC-AC conversion through the inverter circuit. The purpose of achieving reliable operation of the boost inverter system (or frequency converter) in photovoltaic and single-phase power input related application fields is achieved.

[0089] Furthermore, while adding a pre-made DC-to-DC boost circuit can also increase the inverter's input voltage to above 540VAC, enabling reliable operation, widespread adoption of this approach faces significant resistance due to the bulk, high cost, inconvenient installation, and complex design of a separate DC-to-DC converter. Therefore, this application integrates a BOOST circuit into the existing IGBT inverter circuit, allowing the boost circuit to use the same power supply as the IGBT inverter circuit. This design offers advantages such as high efficiency, compact size, low cost, easy installation, and a simple design.

[0090] 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.

[0091] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A boost inverter system, characterized in that: include: IGBT rectifier circuit, Boost boost circuit, IGBT inverter circuit, first capacitor, second capacitor, third capacitor, fourth capacitor, power supply circuit, Boost drive circuit and IGBT inverter drive circuit; The IGBT rectifier circuit, the first capacitor, the second capacitor, the Boost circuit, the third capacitor, the fourth capacitor, and the IGBT inverter circuit are connected in parallel in sequence; The voltage input end of the power supply circuit is connected to the output end of the Boost boost circuit; the inverter upper bridge drive voltage output end of the power supply circuit is connected to the upper bridge power input end of the IGBT inverter drive circuit; the inverter lower bridge-BOOST drive voltage input end of the power supply circuit is connected to the lower bridge power input end of the IGBT inverter drive circuit and the power input end of the Boost drive circuit; The drive signal output terminal of the IGBT inverter drive circuit is connected to the drive signal input terminal of the IGBT inverter circuit; The driving signal output terminal of the Boost driving circuit is connected to the driving signal input terminal of the Boost voltage-increasing circuit.

2. The boost inverter system according to claim 1, characterized in that: The IGBT rectifier circuit includes: a first rectifier branch, a second rectifier branch, and a third rectifier branch connected in parallel; the first rectifier branch includes a first diode and a second diode connected in series, and the connection direction is consistent; the first diode and the third rectifier branch are connected in parallel; Second diode A first power input port is provided between the two rectifier branches; the two rectifier branches include a third diode and a fourth diode connected in series, and the connection directions are consistent; a second power input port is provided between the third diode and the fourth diode; the three rectifier branches include a fifth diode and a sixth diode connected in series, and the connection directions are consistent; a third power input port is provided between the fifth diode and the sixth diode.

3. The boost inverter system according to claim 1, characterized in that: The Boost circuit includes: a first boost circuit and a second boost circuit connected in parallel, the first boost circuit includes a first inductor and a seventh diode, one end of the first inductor is connected to the cathode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the seventh diode, and the anode of the seventh diode is connected to the first input terminal of the IGBT inverter circuit; the second boost circuit includes a second inductor and an eighth diode, one end of the second inductor is connected to the anode of the diode included in the IGBT rectifier circuit, and the other end is connected to the anode of the eighth diode, and the anode of the eighth diode is connected to the first input terminal of the IGBT inverter circuit; The Boost boost circuit also includes a seventh power tube, an eighth power tube and a resistor. The drain of the seventh power tube is connected between the first inductor and the seventh diode, the source is connected to one end of the resistor, and the gate is the first Boost drive signal input end: the drain of the eighth power tube is connected between the second inductor and the eighth diode, the source end is connected to one end of the resistor, and the gate is the second Boost drive signal input end; the other end of the resistor is connected to the positive electrode of the diode included in the IGBT rectifier circuit.

4. The boost inverter system according to claim 1, characterized in that: The Boost drive circuit has two optocoupler isolation drives with the same configuration; for each optocoupler isolation drive, an original Boost drive signal receiving end and an amplified Boost drive signal output end are provided, the original Boost drive signal receiving end is connected to the control chip of the Boost boost circuit, and the amplified Boost drive signal output end is connected to the gate of the power tube of the Boost boost circuit.

5. The boost inverter system according to claim 4, characterized in that: The boost inverter system further includes a Boost control chip, and the Boost control chip is signal-connected to the Boost drive circuit.

6. The boost inverter system according to claim 1, characterized in that: The IGBT inverter circuit includes: a first inverter branch, a second inverter branch and a third inverter branch connected in parallel; each inverter branch includes two power switching tubes connected in series, and the emitter of one power switching tube is connected to the collector of the other power switching tube, and the base is connected to the output end of the amplified inverter drive signal of the IGBT inverter drive circuit.

7. The boost inverter system according to claim 6, characterized in that: The IGBT inverter circuit includes a U-phase output, a V-phase output and a W-phase output, which are respectively denoted as U_out, V_out and W_out; The power supply circuit includes a transformer, the input end of the transformer is connected to the output end of the Boost boost circuit, and is used to provide a working power supply for the transformer; the transformer is used to generate inverter drive voltages U_PH, V_PH, W_PH and PL, wherein the reference ground of U_PH is shared with the U-phase output of the IGBT inverter circuit, and is used to drive the upper bridge power device of the U phase of the inverter circuit; the reference ground of V_PH is shared with the V-phase output, and is used to drive the upper bridge power device of the V phase of the inverter circuit; the reference ground of W_PH is shared with the W-phase output, and is used to drive the upper bridge power device of the W phase of the inverter circuit. PL is used to drive the three-phase lower bridge power device of the inverter circuit, and PL is also connected to the power device in the Boost drive circuit to provide power for its drive.

8. The boost inverter system according to claim 1, characterized in that: The IGBT inverter drive circuit is driven by a 6-way optocoupler isolation. The primary sides of these 6 optocouplers share a common ground with the DSP and receive control signals from the DSP. On the secondary side, the three optocouplers that control the lower bridge power devices of the inverter circuit are powered by PL, and the remaining three are powered by corresponding phase drive voltages.

9. The boost inverter system according to claim 4, characterized in that: The boost inverter system further includes a DSP, which is signal-connected to the IGBT inverter drive circuit to provide a drive signal to the IGBT inverter drive circuit.

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