Digital high-power inverter circuit

Abstract

The invention discloses a digital high-power inverter circuit, which comprises an auxiliary power unit, a power unit, a control unit and a heat dissipation unit, and is characterized in that the auxiliary power unit is connected with the control unit, the power unit is connected with the control unit, and the heat dissipation unit is connected with the power unit; the power unit comprises an input filtering unit and a DC-AC converter, the DC-AC converter comprises a switching tube, a filtering inductor, a filtering capacitor and the like, the control unit comprises a main control unit and a driving unit, the main control unit and the driving unit are connected, the main control unit and the driving unit are both connected with the auxiliary power unit, and the driving unit is further connected with the power unit; the device is used for achieving the functions of overvoltage and overcurrent flexible setting, sound and light alarm, fault display and the like. The problems of low flexibility, applicability, reliability and the like of a traditional inverter unit are effectively solved.

Description

Technical Field

[0001] The invention relates to an inverter technology for electric energy conversion, and in particular to a digital high-power inverter circuit. Background Art

[0002] With the continuous development of power electronics technology and the continuous expansion of its application fields, inverter technology, as one of the four major categories of power conversion, has been widely used in life, production and other occasions. Its core function is to convert direct current into alternating current to meet the needs of various devices for alternating current. As one of the core components of power electronic equipment, the research on inverter unit plays an important role in meeting market demand and promoting industrial development.

[0003] Traditional inverter units mostly use analog control or a combination of analog and digital control systems. This control method requires a large number of discrete components and circuit boards, resulting in high hardware costs and reduced system reliability. At the same time, the complexity of the control circuit also increases the difficulty of debugging and maintenance. Once the hardware circuit is completed, the control strategy cannot be changed, and it cannot adapt to changes in requirements in different application scenarios, lacking flexibility.

[0004] Traditional inverter units have certain problems with output waveform quality. Due to the limitations of analog control methods, the AC waveform output by the inverter unit may have problems such as distortion and high harmonic content, which affects the power supply quality. Since the hardware circuit of traditional inverter units is fixed, it is difficult to upgrade. If performance needs to be improved or new functions need to be added, the entire inverter unit often needs to be redesigned or modified.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a digital high-power inverter circuit to solve the above technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] The digital high-power inverter circuit of the present invention comprises an auxiliary power unit, a power unit, a control unit, and a heat dissipation unit, wherein the auxiliary power unit is connected to the control unit, the power unit is connected to the control unit, and the heat dissipation unit is connected to the power unit;

[0009] The power unit includes an input filter unit and a DC-AC converter, wherein the DC-AC converter includes switch tubes Q1-Q4, filter inductors L1-L2, and filter capacitors Cout, and the switch tubes Q1-Q4 include IGBTs;

[0010] The collectors of the switch tubes Q1 and Q3 are both connected to the positive electrode of the input filter unit, the collector of the switch tube Q2 is respectively connected to the emitter of the switch tube Q1 and the filter inductor L1, the collector of the switch tube Q4 is respectively connected to the emitter of the switch tube Q3 and the filter inductor L2, and the emitters of the switch tubes Q2 and Q4 are connected to the negative electrode of the input filter unit;

[0011] The filter capacitor Cout is connected in parallel between the filter inductors L1 and L2;

[0012] The control unit includes a main control unit and a drive unit, the main control unit is connected to the drive unit, and both are connected to the auxiliary power unit, wherein the drive unit is also connected to the power unit;

[0013] The main control unit includes an SPWM drive module;

[0014] The driving unit includes gate drivers US1 to US4, wherein the gate driver US1 is connected to the gate of the switch tube Q1, the gate driver US2 is connected to the gate of the switch tube Q2, the gate driver US3 is connected to the gate of the switch tube Q3, and the gate driver US4 is connected to the gate of the switch tube Q4;

[0015] The gate drivers US1 - US4 include IGBT drivers.

[0016] Compared with the prior art, the digital high-power inverter circuit provided by the present invention can achieve high-power output, and its power capacity can reach several kilowatts. It adopts an intelligent control unit, and its control method can reduce the no-load waveform distortion rate. It has built-in various protection and communication functions. The operating status and related data of the inverter, configuration parameters, and control method of the setting module can be queried through serial port communication, which effectively solves the problems of low flexibility, applicability, and reliability of traditional inverter units. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a principle block diagram of the intelligent high-power inverter unit of the present invention;

[0018] Figure 2 for Figure 1 Schematic diagram of the circuit topology of the medium power unit;

[0019] Figure 3 for Figure 1 Principle block diagram of the control unit. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0021] First, the terms that may be used in this article are explained as follows:

[0022] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0023] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0024] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0025] The contents not described in detail in the examples of the present invention belong to the prior art known to professionals in the field. If no specific conditions are specified in the examples of the present invention, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used in the examples of the present invention, they are all conventional products that can be purchased commercially.

[0026] The digital high-power inverter circuit of the present invention comprises an auxiliary power unit, a power unit, a control unit, and a heat dissipation unit, wherein the auxiliary power unit is connected to the control unit, the power unit is connected to the control unit, and the heat dissipation unit is connected to the power unit;

[0027] The power unit includes an input filter unit and a DC-AC converter, wherein the DC-AC converter includes switch tubes Q1-Q4, filter inductors L1-L2, and filter capacitors Cout, and the switch tubes Q1-Q4 include IGBTs;

[0028] The collectors of the switch tubes Q1 and Q3 are both connected to the positive electrode of the input filter unit, the collector of the switch tube Q2 is respectively connected to the emitter of the switch tube Q1 and the filter inductor L1, the collector of the switch tube Q4 is respectively connected to the emitter of the switch tube Q3 and the filter inductor L2, and the emitters of the switch tubes Q2 and Q4 are connected to the negative electrode of the input filter unit;

[0029] The filter capacitor Cout is connected in parallel between the filter inductors L1 and L2;

[0030] The control unit includes a main control unit and a drive unit, the main control unit is connected to the drive unit, and both are connected to the auxiliary power unit, wherein the drive unit is also connected to the power unit;

[0031] The main control unit includes an SPWM drive module;

[0032] The driving unit includes gate drivers US1 to US4, wherein the gate driver US1 is connected to the gate of the switch tube Q1, the gate driver US2 is connected to the gate of the switch tube Q2, the gate driver US3 is connected to the gate of the switch tube Q3, and the gate driver US4 is connected to the gate of the switch tube Q4;

[0033] The gate drivers US1 - US4 include IGBT drivers.

[0034] The inverter circuit is realized by a power unit and a digital drive unit.

[0035] The switching tubes are driven by gate drivers US1 to US4 to realize inverter output.

[0036] Digital high-power inverter output is achieved by controlling the switch tubes Q1 to Q4.

[0037] In summary, it can be seen that the digital high-power inverter circuit of the embodiment of the present invention adopts a vertical multi-layer layout, which reduces the size of the module and adopts domestically produced devices. The output can be connected to inductive loads, capacitive loads and other devices. It has multiple protection functions, providing DC bus overvoltage and undervoltage protection, AC output undervoltage protection, overload alarm prompt, overload protection indication, overcurrent protection indication, overtemperature protection indication and short circuit protection indication, etc.; built-in UART serial port communication function, through which the inverter operation status and related data, configuration parameters, and setting module voltage mode and current mode control mode can be queried.

[0038] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the embodiments of the present invention are described in detail with specific embodiments below.

[0039] Example 1

[0040] like Figure 1 , 2 、3 as shown:

[0041] Reference Figure 1 As shown, the intelligent high-power inverter unit is divided into four parts: an auxiliary power unit, a power unit, a control unit, and a heat dissipation unit. It can convert the 310V~400V DC high-voltage DC bus voltage supplied by the previous stage into a single-phase AC 220V pure sinusoidal wave voltage.

[0042] Reference Figure 2 As shown in the figure, the power unit uses a full-bridge inverter circuit topology. The full-bridge inverter can convert direct current into alternating current and can achieve high power output. Its power capacity can reach several kilowatts. Therefore, the full-bridge inverter is widely used in power electronic equipment, inverter power supply, and motor drive system. The full-bridge inverter uses resonance technology to reduce switching losses and improve transmission efficiency. Its output voltage presents a sinusoidal waveform. Because its output voltage is stable and not prone to noise interference, it has a wide range of applications. The full-bridge inverter has the advantages of large power capacity, high efficiency, good output voltage waveform, high reliability, and easy control.

[0043] Reference Figure 3 As shown in the figure, the main control unit in the control unit adopts the EGS005Q model SPWM drive module, and then the KA962F driver of the drive unit adjusts the drive waveform to drive the IGBT. The LD20-23B24R2 module of the auxiliary power unit provides a DC 24V voltage for the KA962F driver, and the EG1185 module provides a DC 15V and 5V supply voltage for the EGS005Q model SPWM drive module.

[0044] DC-AC converters generally use voltage-mode SPWM control as the main control, and the switching frequency is generally around 20KHz. The selected LC filter inductance is relatively large, and the inductance is easy to saturate under heavy load. The EGS005Q model SPWM driver module is small in size and highly integrated. It uses two control modes, voltage mode and current mode, to achieve no-load waveform distortion rate less than 1.5%, full-load waveform distortion rate less than 3%, and high-precision output voltage characteristics, which can meet the waveform requirements of the inverter. EGS005Q integrates two 600V half-bridge high-voltage MOS tube drivers with a driving capacity of ±2A; four independent MOS tube peak current protection circuits and a comparator with four built-in 200mV reference sources can set the protection value; four high-speed op amps and one high-speed comparator, two op amps are used for AC current amplifiers, one op amp is used for AC output voltage feedback, one op amp is used for short-circuit protection, and one comparator is used for current limiting protection; the output voltage and output current are processed in real time for each PWM cycle, which can achieve accurate tracking. It has multiple protection functions, including DC bus overvoltage and undervoltage protection, AC output undervoltage protection, overload alarm, overload protection indication, overcurrent protection indication, overtemperature protection indication and short circuit protection indication, etc. It has built-in UART serial communication function, which can query the inverter operation status and related data, configure parameters, and set the module voltage mode and current mode control mode through serial communication.

[0045] The driving waveform generated by EGS005Q is connected to the KA962 single-tube medium-to-high-power IGBT driver, which can drive an IGBT below 300A / 1700V, increasing the driving capability of the EGS005Q driver module. It can be used directly according to the default value, or the blind time, soft shutdown speed, and restart time after a fault can be adjusted as needed.

[0046] The intelligent high-power inverter unit adopts a vertical multi-layer layout. The heat dissipation unit adopts an aluminum substrate. The power tube devices with severe heat generation are placed on the bottom plate, and the auxiliary power unit and control unit are placed on the upper layer, which reduces the size of the intelligent high-power inverter unit.

[0047] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A digital high-power inverter circuit, characterized in that: It includes an auxiliary power unit, a power unit, a control unit, and a heat dissipation unit, wherein the auxiliary power unit is connected to the control unit, the power unit is connected to the control unit, and the heat dissipation unit is connected to the power unit; The power unit includes an input filter unit and a DC-AC converter, wherein the DC-AC converter includes a switch tube (Q1-Q4), a filter inductor (L1-L2), and a filter capacitor Cout, and the switch tube (Q1-Q4) includes an IGBT; The collectors of the switch tubes (Q1 and Q3) are both connected to the positive electrode of the input filter unit, the collector of the switch tube 2 (Q2) is respectively connected to the emitter of the switch tube 1 (Q1) and the filter inductor 1 (L1), the collector of the switch tube 4 (Q4) is respectively connected to the emitter of the switch tube 3 (Q3) and the filter inductor 2 (L2), and the emitters of the switch tubes (Q2 and Q4) are connected to the negative electrode of the input filter unit; The filter capacitor Cout is connected in parallel between the filter inductors (L1-L2); The control unit includes a main control unit and a drive unit, the main control unit is connected to the drive unit, and both are connected to the auxiliary power unit, wherein the drive unit is also connected to the power unit; The main control unit includes an SPWM drive module; The driving unit comprises gate drivers (US1-US4), wherein gate driver one (US1) is connected to the gate of switch tube one (Q1), gate driver two (US2) is connected to the gate of switch tube two (Q2), gate driver three (US3) is connected to the gate of switch tube three (Q3), and gate driver four (US4) is connected to the gate of switch tube four (Q4); The gate drivers (US1-US4) include IGBT drivers.

2. The digital high-power inverter circuit according to claim 1, characterized in that: The inverter circuit is realized by a power unit and a digital drive unit.

3. The digital high-power inverter circuit according to claim 2, characterized in that: The gate driver (US1 to US4) drives the switch tube to realize the inverter output.

4. The digital high-power inverter circuit according to claim 3 is characterized in that: Digital high-power inverter output is achieved by controlling the switch tubes (Q1-Q4).

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