Frequency converter power supply compensation and endurance system based on super capacitor

Abstract

The utility model discloses a frequency converter power supply compensation and endurance system based on a super capacitor, which comprises an external power grid, a load frequency converter electrically connected with the external power grid, a three-phase rectifier module electrically connected with the external power grid, and a power supply compensation and endurance unit arranged between the three-phase rectifier module and a direct current bus of the load frequency converter, the system control unit is matched with the power supply compensation and endurance unit, and the power supply compensation and endurance unit comprises a buck-boost bidirectional conversion module, an energy storage inductor, a super capacitor energy storage module and a unidirectional diversion module. According to the system, through cooperative work of the power supply compensation and endurance unit and the system control mainboard, effective utilization of external power grid power supply and stable power supply of the load frequency converter when the power grid fluctuates or power supply is insufficient are realized.

Description

Technical Field

[0001] The utility model relates to the field of electric power, and more specifically, to a frequency converter power supply compensation and endurance system based on a super capacitor. Background Technique

[0002] With the increasing application of frequency conversion technology in various fields, especially in the industrial field, a large number of frequency converters are newly added every year in the industry. Coupled with the cumulative quantity in the past, the total quantity has become very large.

[0003] According to the transmission characteristics of AC mains power, in the same power supply network or adjacent power supply networks, a large number of frequency converter devices exist simultaneously. At any moment, a large number of frequency converters may start simultaneously. When this situation occurs, it may cause an instantaneous voltage drop in the voltage of the same power supply point range. Especially in the industrial power supply network, it is common that when large power-consuming equipment transiently takes on the equipment work, it will cause a certain degree of heavy load impact on the power grid. This situation will also cause an instantaneous voltage drop in the voltage of the same power supply point range.

[0004] Moreover, due to the continuous development of various new energy technologies, the current grid connection of various unstable power generation networks such as photovoltaic power generation and wind power generation with the mains power will randomly cause fluctuations in the total power supply capacity of the power grid to different degrees. For example, a voltage stabilization device based on super capacitor energy storage disclosed in Patent No. CN201721331767.8, during the use of this device, because there is no unidirectional conduction module, during the charging and discharging process of the super capacitor, it is very easy to generate current impact on the internal circuit. Summary of the Invention

[0005] An object of the utility model is to solve at least the above problems and / or defects, and provide at least the advantages described later.

[0006] To achieve these objects and other advantages according to the utility model, a frequency converter power supply compensation and endurance system based on a super capacitor is provided, including: an external power grid, a load frequency converter electrically connected to the external power grid, and further including: a three-phase rectification module electrically connected to the external power grid, a power supply compensation and endurance unit arranged between the three-phase rectification module and the DC bus of the load frequency converter, and a system control unit cooperating with the power supply compensation and endurance unit. The power supply compensation and endurance unit includes: a buck-boost bidirectional conversion module, an energy storage inductor, a super capacitor energy storage module, and a unidirectional current guiding module;

[0007] Among them, the output terminals of the three-phase rectification module are electrically connected to the buck-boost bidirectional conversion module and the system control unit respectively. The output terminals of the buck-boost bidirectional conversion module are electrically connected to the energy storage inductor and the unidirectional current guiding module respectively. The output terminal of the energy storage inductor is electrically connected to the supercapacitor energy storage module and the system control unit respectively. The output terminal of the supercapacitor energy storage module is electrically connected to the load frequency converter through the unidirectional current guiding module. The unidirectional current guiding module is electrically connected to the system control unit. The unidirectional current guiding module is electrically connected to the load frequency converter through a parallel connection relay, and the parallel connection relay is connected to the system control unit.

[0008] Preferably, it further includes a filter circuit disposed between the three-phase rectification module and the load frequency converter.

[0009] Preferably, the three-phase rectification module is configured as any one of a three-phase rectifier bridge mode, a diode combination mode, an IGBT or MOS transistor combination mode.

[0010] Preferably, the supercapacitor energy storage module is configured to be obtained by connecting 200 supercapacitor monomers in series, and the capacitance range of the supercapacitor monomer is between 100F and 3000F.

[0011] Preferably, the system control main board is configured to include a DSP control unit, a wide voltage range power supply, a voltage detection circuit, and a current detection circuit. One end of the voltage detection circuit is connected to the DSP control module, and the other end is connected to the output terminal of the three-phase rectification module. One end of the current detection circuit is connected to the DSP control module, and the other end is connected to the output terminal of the unidirectional current guiding module. The DSP control module is connected to the parallel connection relay;

[0012] Among them, the wide voltage range power supply is configured to adopt a switching power supply mode, and its input voltage range is configured to be 100V to 800V. The wide voltage range power supply is used to ensure that each sub-circuit of the energy recovery system can be normally powered within the full voltage range of the three-phase commercial power;

[0013] The DSP control unit is configured to adopt TMS32F280025;

[0014] The voltage detection circuit is configured to perform detection by using high-precision resistor voltage division;

[0015] The current detection circuit is configured to perform capacitance detection by using a Hall current sensor method.

[0016] Preferably, the filter circuit is configured to include:

[0017] A filter capacitor C1 disposed between the three-phase rectification module and the buck-boost bidirectional conversion module;

[0018] A filter capacitor C2 is arranged between the energy storage inductor and the supercapacitor energy storage module, and C2 is electrically connected to the positive and negative terminals of the supercapacitor energy storage module.

[0019] Preferably, the filter capacitors C1 and C2 are configured as any one of electrolytic capacitors and thin-film capacitors.

[0020] Preferably, the unidirectional current guiding module is configured as any one of a three-phase rectifier bridge mode, a diode combination mode, an IGBT or MOS tube combination mode.

[0021] Preferably, it further includes a communication module and a display module connected to the DSP control module.

[0022] The present utility model has at least the following beneficial effects: The present utility model provides a frequency converter power supply compensation and endurance system based on supercapacitors. Through the collaborative work of the power supply compensation and endurance unit and the system control main board, the system realizes the effective utilization of the external power grid power supply and the stable power supply of the load frequency converter when the power grid fluctuates or the power supply is insufficient.

[0023] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the system composition block diagram of the present utility model;

[0025] Figure 2 It is the composition block diagram of the system control unit;

[0026] Figure 3 It is the wiring diagram of the load frequency converter of the present utility model and the present utility model;

[0027] Figure 4 It is the circuit diagram of the present utility model.

[0028] Reference numerals in the figures: 1, external power grid; 2, three-phase rectification module; 3, parallel connection relay; 4, load frequency converter; 5, power supply compensation and endurance unit; 51, buck-boost bidirectional conversion module; 52, energy storage inductor; 53, supercapacitor energy storage module; 54, unidirectional current guiding module; 6, system control unit; 61, DSP control module; 62, wide voltage range power supply; 63, voltage detection circuit; 64, current detection circuit; 7, filter capacitor C1; 8, filter capacitor C2; 9, communication module; 10, display module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following further describes the present utility model in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0030] It should be understood that terms such as "having", "including", and "comprising" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0031] It should be noted that in the description of the present utility model, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0032] In the description of the present utility model, unless otherwise clearly specified and defined, terms such as "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0033] In addition, in the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0034] Figure 1 There is shown a frequency converter power supply compensation and endurance system based on a super capacitor according to the present utility model, including: an external power grid 1, a load frequency converter 4 electrically connected to the external power grid 1, and further including: a three-phase rectification module 2 electrically connected to the external power grid 1, a power supply compensation and endurance unit 5 disposed between the DC bus of the three-phase rectification module 2 and the load frequency converter 4, and a system control unit 6 cooperating with the power supply compensation and endurance unit 5. The power supply compensation and endurance unit 5 includes: a buck-boost bidirectional conversion module 51, a storage inductor 52, a super capacitor energy storage module 53, and a unidirectional current guiding module 54;

[0035] Among them, the output terminals of the three-phase rectification module 2 are respectively electrically connected to the buck-boost bidirectional conversion module 51 and the system control unit 6. The output terminals of the buck-boost bidirectional conversion module 51 are respectively electrically connected to the energy storage inductor 52 and the unidirectional current guiding module 54. The output terminal of the energy storage inductor 52 is respectively electrically connected to the supercapacitor energy storage module 53 and the system control unit 6. The output terminal of the supercapacitor energy storage module 53 is electrically connected to the load frequency converter 4 through the unidirectional current guiding module 54. The unidirectional current guiding module 54 is electrically connected to the system control unit 6. The unidirectional current guiding module 54 is electrically connected to the load frequency converter 4 through the parallel connection relay 3. The parallel connection relay 3 is connected to the system control unit 6.

[0036] Working principle:

[0037] When the external power grid 1 powers on the internal system, the three-phase rectification module 2 converts the three-phase alternating current into direct current. The buck-boost energy conversion is realized through the buck-boost bidirectional conversion module 51 and the energy storage inductor 52. Through the closed-loop control of the system control unit 6, the current limiting and voltage limiting are realized to charge the supercapacitor energy storage unit. After charging to the rated 530V (the specific voltage can be set through the touch screen and communication in the system control unit 6), it enters the floating charge stage subsequently. Thereafter, the system control unit 6 connects the output direct current through the parallel connection relay 3 to the direct current bus of the matching frequency converter. When the voltage of the power grid suddenly drops, the system control unit 6 will seamlessly and automatically compensate electric energy for the frequency converter. When the power grid is powered off, the system control unit 6 will continuously supply power to the matching frequency converter according to the set power and time. After the duration ends, the system control unit 6 controls the parallel connection relay 3 to disconnect and stops the whole machine from working. During the continuous emergency power supply period, the voltage of the supercapacitor energy storage unit will decrease as it is used. When the voltage drops to a certain value (automatically judged by the system), the system control unit 6 will control the buck-boost bidirectional conversion module 51 to switch to the boost mode, boost the electric energy of the supercapacitor energy storage unit through self-booting, and continue to provide energy for the matching frequency converter, so as to achieve the purpose of improving the utilization rate of the supercapacitor capacity.

[0038] Among them, the buck-boost bidirectional conversion module 51 realizes the bidirectional high-frequency switching conversion of BUCK and BOOST. The internal drive unit realizes the high-frequency drive of the IGBT or MOS tube in the buck-boost bidirectional conversion module 51, and realizes the high-low tube interlock and pulse overcurrent protection. The energy storage inductor 52 realizes the energy conversion and temporary storage during the electromagnetic conversion of BUCK and BOOST.

[0039] In the above technical solution, it further includes a filter circuit disposed between the three-phase rectification module 2 and the load frequency converter 4. With this technical solution, the three-phase rectification module 2 generates harmonics during operation. If these harmonics are not processed, they will pollute the power grid, affecting the stability of the power grid and the normal operation of other devices. The filter circuit can effectively absorb or suppress these harmonics, reducing their impact on the power grid and subsequent devices. By filtering out harmonics and voltage fluctuations, the filter circuit can ensure that the voltage waveform supplied to the load frequency converter 4 is smoother and more stable, thereby improving the power quality of the entire system. This is particularly important for application scenarios that require a high-precision and high-stability power supply.

[0040] In the above technical solution, the three-phase rectification module 2 is configured as any one of a three-phase rectifier bridge mode, a diode combination mode, an IGBT or MOS transistor combination mode. With this technical solution, in the three-phase rectifier bridge mode, this mode has a simple structure and low cost, and is suitable for most application scenarios that require a DC power supply. In the diode combination mode, different rectification effects and voltage regulation capabilities can be achieved by selecting the number and connection method of diodes. The IGBT or MOS transistor combination mode uses controllable semiconductor switching devices (IGBT or MOS transistors), making the rectification process more flexible and controllable. By controlling the on and off of these switching devices, not only can the rectification function be achieved, but also the output voltage and current can be more precisely controlled and regulated. In actual operation, the appropriate mode can be selected according to actual needs.

[0041] In the above technical solution, the supercapacitor energy storage module 53 is configured to be obtained by connecting 200 supercapacitor monomers in series, and the capacitance range of the supercapacitor monomers is between 100F and 3000F. With this technical solution, the supercapacitor energy storage module 53 is configured to be obtained by connecting 200 supercapacitor monomers in series. This design with a high series number can significantly increase the voltage level of the energy storage module, thus meeting the requirements of high-voltage systems. At the same time, by connecting multiple monomers in series, different-capacity monomers can be selected for combination according to specific application requirements while ensuring the voltage level to achieve the required energy storage capacity. The capacitance range of the supercapacitor monomers is set between 100F and 3000F, covering a variety of capacity specifications from small to large. Different-capacity monomers can be flexibly selected for combination according to factors such as actual energy storage requirements, cost budget, and space limitations. Smaller-capacity monomers may be suitable for application scenarios that require fast charge and discharge but have low total energy storage requirements, while larger-capacity monomers are suitable for scenarios that require long-term energy storage or high-energy output.

[0042] A supercapacitor monomer equalization circuit adapted to the supercapacitor monomer, and the supercapacitor monomer equalization circuit is a prior art and will not be elaborated here. It is used to monitor the voltage status of each monomer in real time. This is a key link to ensure the safe and reliable operation of the supercapacitor energy storage module 53. Through voltage detection, the system can timely detect and handle voltage abnormalities, such as overvoltage, undervoltage or voltage imbalance of monomers, and achieve the purpose of equalizing the voltages of each monomer of the overall supercapacitor by releasing the energy of the higher-voltage monomers.

[0043] In the above technical solution, the system control main board is configured to include a DSP control unit, a wide-voltage-range power supply 62, a voltage detection circuit, and a current detection circuit 64. One end of the voltage detection circuit is connected to the DSP control module 61, and the other end is connected to the output end of the three-phase rectification module 2. One end of the current detection circuit 64 is connected to the DSP control module 61, and the other end is connected to the output end of the unidirectional current guiding module 54. The DSP control module 61 is connected to the parallel line relay 3;

[0044] Among them, the wide-voltage-range power supply 62 is configured to adopt a switching power supply method, and its input voltage range is configured at 100V~800V. The wide-voltage-range power supply 62 is used to ensure that each sub-circuit of the energy recovery system can be normally powered within the full voltage range of the three-phase commercial power;

[0045] The DSP control unit is configured to adopt TMS32F280025;

[0046] The voltage detection circuit is configured to perform detection by using high-precision resistor voltage division;

[0047] The current detection circuit 64 is configured to perform current detection by using a Hall current sensor. Adopting this technical solution, the wide-voltage-range power supply 62:

[0048] The wide-voltage-range power supply 62 designed by adopting the switching power supply method has its input voltage range set at 100V~800V, ensuring that the system can work normally within the full voltage range of the three-phase commercial power (usually alternating current, but here it may refer to the DC voltage range after three-phase rectification). This is particularly important for areas or application scenarios with large grid voltage fluctuations, and can significantly improve the adaptability and stability of the system. The high efficiency characteristic of the switching power supply also helps to reduce energy loss and improve the overall energy efficiency of the system.

[0049] The system control switch adopts a double-knife boat-shaped switch. This switch has the advantages of simple operation, reliable contact, long service life, etc., and is suitable for occasions that require frequent operation or as an emergency stop switch.

[0050] DSP control module 61:

[0051] The TMS32F280025 is selected as the DSP control unit. This DSP chip has high-performance computing capabilities, rich peripheral interfaces, and powerful control capabilities, making it very suitable for power electronic systems that require complex control algorithms. The introduction of the TMS32F280025 enables the system to implement fast and accurate control strategies, improving the system's dynamic response and stability.

[0052] Voltage detection circuit:

[0053] The voltage is detected by using a high-precision resistor voltage division method. The advantages of this method are simplicity, reliability, and low cost. Through a carefully designed voltage division resistor network, the voltage of each key node in the system can be accurately measured, providing an accurate voltage feedback signal for the DSP control unit, thereby achieving precise control of the system voltage.

[0054] Current detection circuit 64:

[0055] A Hall current sensor is selected for current detection because Hall current sensors have advantages such as non-contact measurement, high precision, high linearity, and good electromagnetic isolation performance. Through the Hall current sensor, the current in the system can be quickly and accurately measured, providing the necessary current feedback signal for the DSP control unit to achieve current closed-loop control and improve the stability and safety of the system. At the same time, the system control unit 6 is also provided with a display module 10 and a communication module 9. The system parameters can be manually designed through the touch display module 10 or externally / remotely set through the communication module 9. The set parameters will be saved in the DSP control module 61. When the system is powered off, the previously set parameters will be automatically recalled when the system is used next time.

[0056] The DSP control unit is connected to components such as the voltage detection circuit, current detection circuit 64, and parallel line relay 3, receives the signals they provide, and outputs corresponding control signals according to these signals and the preset control strategy.

[0057] In the above technical solution, the filter circuit is configured to include:

[0058] A filter capacitor C17 provided between the three-phase rectification module 2 and the buck-boost bidirectional conversion module 51;

[0059] The filter capacitor C28 is arranged between the energy storage inductor 52 and the supercapacitor energy storage module 53, and C2 is electrically connected to the positive and negative terminals of the supercapacitor energy storage module 53. With this technical solution, among them, the filter capacitor C17 is a high-voltage filter capacitor, and the filter capacitor C28 is a low-voltage filter capacitor. The filter capacitor C17 placed between the three-phase rectification module 2 and the buck-boost bidirectional conversion module 51 undertakes to smooth the high-voltage DC bus voltage. The DC voltage output by the three-phase rectification module 2 is usually relatively high and may be accompanied by large voltage fluctuations. The filter capacitor C17 can effectively absorb these voltage fluctuations and provide a stable high-voltage DC power supply for the subsequent buck-boost bidirectional conversion module 51. This is for protecting the electronic components in the buck-boost bidirectional conversion module 51, improving its conversion efficiency and stability.

[0060] In the above technical solution, the filter capacitors C17 and C2 are configured as any one of electrolytic capacitors and thin-film capacitors. With this technical solution, by selecting an electrolytic capacitor or a thin-film capacitor as the filter capacitors C17 and C2, it can be optimized according to the specific requirements of the system. For example, in the case where large-capacity filtering is required and cost is sensitive, an electrolytic capacitor can be selected; while in the case where high requirements for stability and lifespan are required, a thin-film capacitor can be selected. In addition, it can also be comprehensively considered according to factors such as the voltage level, current characteristics, and working environment of the system to select the most suitable type of filter capacitor.

[0061] In the above technical solution, it further includes: a communication module 9 and a display module 10 connected to the DSP control module 61. With this technical solution, the setting of the system parameters can be manually designed through the display module 10 or externally or remotely set through the communication module 9. The set parameters will be saved in the DSP control module 61. When the system is powered off, the previously set parameters will be automatically recalled when the system is used next time.

[0062] Although the embodiments of the present utility model have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present utility model. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present utility model is not limited to specific details and the illustrations shown and described here.

Claims

1. A frequency converter power supply compensation and endurance system based on supercapacitor, comprising: An external power grid, a load frequency converter electrically connected to the external power grid, characterized in that it also includes: a three-phase rectifier module electrically connected to the external power grid, a power supply compensation and endurance unit arranged between the three-phase rectifier module and the DC bus of the load frequency converter, and a system control unit coordinated with the power supply compensation and endurance unit, wherein the power supply compensation and endurance unit includes: a step-up and step-down bidirectional conversion module, an energy storage inductor, a supercapacitor energy storage module, and a unidirectional guide module; Among them, the output ends of the three-phase rectifier module are electrically connected to the buck-boost bidirectional conversion module and the system control unit respectively, the output ends of the buck-boost bidirectional conversion module are electrically connected to the energy storage inductor and the unidirectional conduction module respectively, the output ends of the energy storage inductor are electrically connected to the supercapacitor energy storage module and the system control unit respectively, the output end of the supercapacitor energy storage module is electrically connected to the load inverter through the unidirectional conduction module, the unidirectional conduction module is electrically connected to the system control unit, the unidirectional conduction module is electrically connected to the load inverter through the paralleling relay, and the paralleling relay is connected to the system control unit.

2. The inverter power supply compensation and endurance system based on supercapacitor according to claim 1 is characterized in that: Also includes: A filter circuit is arranged between the three-phase rectifier module and the load inverter.

3. The inverter power supply compensation and endurance system based on supercapacitor according to claim 1, characterized in that: The three-phase rectifier module is configured as any one of a three-phase rectifier bridge mode, a diode combination mode, an IGBT or MOS tube combination mode.

4. The inverter power supply compensation and endurance system based on supercapacitor according to claim 1, characterized in that: The supercapacitor energy storage module is configured to include 200 supercapacitor cells connected in series, and the capacity range of the supercapacitor cells is between 100F and 3000F.

5. The inverter power supply compensation and endurance system based on supercapacitor according to claim 1, characterized in that: The system control unit is configured to include a DSP control module, a wide voltage range power supply, a voltage detection circuit, and a current detection circuit. One end of the voltage detection circuit is connected to the DSP control module, and the other end is connected to the output end of the three-phase rectifier module. One end of the current detection circuit is connected to the DSP control module, and the other end is connected to the output end of the unidirectional guide module. The DSP control module is connected to the paralleling relay. The wide voltage range power supply is configured to adopt a switching power supply mode, and its input voltage range is configured in the range of 100V to 800V. The wide voltage range power supply is used to ensure that the energy recovery system sub-circuits can be powered normally within the full voltage range of the three-phase mains; The DSP control module is configured to adopt TMS32F280025; The voltage detection circuit is configured to use high-precision resistance voltage division for detection; The current detection circuit is configured to perform capacitance detection using a Hall current sensor.

6. The inverter power supply compensation and endurance system based on supercapacitor according to claim 2, characterized in that: The filter circuit is configured to include: A filter capacitor C1 is arranged between the three-phase rectifier module and the buck-boost bidirectional conversion module; A filter capacitor C2 is arranged between the energy storage inductor and the supercapacitor energy storage module, and C2 is electrically connected to the positive terminal and the negative terminal of the supercapacitor energy storage module.

7. The inverter power supply compensation and endurance system based on supercapacitor according to claim 6, characterized in that: The filter capacitors C1 and C2 are configured as any one of electrolytic capacitors and film capacitors.

8. The inverter power supply compensation and endurance system based on supercapacitor according to claim 1, characterized in that: The one-way flow guide module is configured to include any one of a three-phase rectifier bridge mode, a diode combination mode, and an IGBT or MOS tube combination mode.

9. The inverter power supply compensation and endurance system based on supercapacitor according to claim 5, characterized in that: Also includes: A communication module and a display module connected to the DSP control module.

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