Power supply cabinet using super capacitor

Abstract

The utility model provides a power supply cabinet using a super capacitor, and relates to the technical field of power supply cabinets. The power supply cabinet comprises a cabinet body and a circuit structure located in the cabinet body, the circuit structure comprises a rectifier transformer, a super capacitor module C and a direct current feeder loop which are connected in sequence, the rectifier transformer is connected with an alternating current input end, and the direct current feeder loop is connected with a load end. And a super capacitor protection circuit is arranged between the rectifier transformer and the super capacitor module C. According to the power supply cabinet provided by the utility model, the super capacitor is adopted as an energy storage device, and the working effect and performance of the super capacitor are ensured by arranging the super capacitor protection circuit; on the basis, the problem that the reliability and the stability of a power supply system are affected due to the fact that a power supply cabinet in the prior art mostly adopts a storage battery as an energy storage device, various limitations exist, the good working effect of the power supply cabinet cannot be achieved easily is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply cabinets, in particular to a power supply cabinet using a super capacitor. Background Art

[0002] The power supply cabinet is an important electrical equipment in the power system, which is used to convert the electric energy of the high-voltage transmission line into low-voltage electric energy for supply to various electrical equipment. The power supply cabinet is usually located in the power distribution room of power plants, substations or industrial occasions, and has important significance and role in ensuring the reliability and stability of the power supply system. The power supply cabinet is equipped with an energy storage device. When the power supply of the power grid is normal, the power supply cabinet converts the AC power provided by the power grid into DC power and stores the charge in the energy storage device for future use. When the power grid fails, the energy storage device can be used to provide backup power and balance voltage fluctuations to maintain the normal operation of various electrical equipment. Therefore, the energy storage device is an important part of the power supply cabinet structure. In order to adapt to the current high-speed development of electricity demand, high-quality energy storage devices with high reliability, high capacity and long life should be used.

[0003] In most existing power supply cabinets, batteries are usually used as energy storage devices; for example, the Chinese patent with publication number CN115360824A provides an intelligent communication DC power supply cabinet, which includes a battery cabinet. However, battery-type energy storage devices have many limitations in practical applications. Specifically: First, due to the low power density of the battery, it is difficult to quickly meet the needs in situations where fast response and high power output are required, which is not conducive to ensuring the working effect of the power supply cabinet and may also affect the stability and reliability of the power supply system. Second, the charging and discharging speed of the battery is slow, usually taking several hours, which will limit the working flexibility and efficiency of the power supply cabinet. Third, the cycle life of the battery is limited and cannot meet long-term power supply needs. The battery needs to be replaced more frequently, which increases the operating cost and maintenance workload, and may also have an adverse effect on the power supply stability of the power supply cabinet. Fourth, the operating temperature range of batteries is relatively narrow, generally -15 to 40°C, which makes their performance more easily affected by the ambient temperature, which in turn affects the working effect of the power cabinet; Fifth, batteries have certain risks of combustion and explosion. For example, the chemical properties of lithium batteries are very unstable. When they are impacted, squeezed or the diaphragm is damaged, they may cause internal short circuits, thereby generating high temperatures and causing combustion or explosion. Therefore, batteries cannot fully meet the high safety requirements of power cabinets. Sixth, batteries often use heavy metals or other toxic substances, such as lead, nickel, cadmium, cobalt, etc., which are highly polluting and not conducive to environmental protection and sustainable development.

[0004] In summary, the utility model provides a power supply cabinet using supercapacitors, which can improve the problems existing in battery power supply cabinets from multiple dimensions, help to comprehensively improve the performance of the power supply cabinet, and thus improve the reliability and stability of the power supply system. Utility Model Content

[0005] The purpose of the utility model is to provide a power supply cabinet using a supercapacitor to solve the following technical problems mentioned in the above background technology: the power supply cabinets in the prior art mostly use batteries as energy storage devices, which have the limitations of low power density, slow charging and discharging speed, limited cycle life, susceptibility to ambient temperature, low safety, and strong pollution, which is not conducive to achieving a good working effect of the power supply cabinet, and thus affects the reliability and stability of the power supply system.

[0006] The utility model is realized by adopting the following technical solutions:

[0007] A power supply cabinet using a supercapacitor comprises a cabinet body and a circuit structure located inside the cabinet body, wherein the circuit structure comprises a rectifier transformer, a supercapacitor module C and a DC feeder loop connected in sequence, wherein the rectifier transformer is connected to an AC input end, the DC feeder loop is connected to a load end, and a supercapacitor protection circuit is also provided between the rectifier transformer and the supercapacitor module C.

[0008] In the power supply cabinet provided by the utility model, a supercapacitor is used as an energy storage device, and a supercapacitor protection circuit is set to ensure the working effect and performance of the supercapacitor. Compared with traditional batteries, the power supply cabinet using supercapacitors has the following advantages: First, the power density of supercapacitors is much higher than that of batteries, and can provide instantaneous high-power output, so in situations where rapid response and high-power output are required, supercapacitors can meet the needs more quickly, based on which it helps the power supply cabinet to manage power distribution more effectively, thereby improving the stability and reliability of the power supply system. Second, supercapacitors can complete the charging and discharging process in a very short time, usually only a few seconds to a few minutes, so it has obvious advantages in situations where frequent charging and discharging are required, so that the power supply cabinet can respond to load changes more quickly, which helps to improve the working flexibility and efficiency of the power supply cabinet. Third, the number of charge and discharge cycles of supercapacitors can reach hundreds of thousands or even millions of times, so its cycle life is far longer than that of batteries, which means that the power supply cabinet has lower operating costs and maintenance workload, thereby improving the overall economy of the power supply system. Fourth, supercapacitors can work in a wide temperature range, generally -40 to 70°C, so they are less likely to be affected by ambient temperature than batteries, which helps to ensure the working effect of the power supply cabinet. Fifth, the working mechanism of supercapacitors does not involve chemical reactions, and they can remain stable even in the case of overcharge or overdischarge, and are not prone to safety accidents such as combustion or explosion, which can meet the high safety requirements of the power supply cabinet. Sixth, supercapacitors do not contain pollutants such as heavy metals, which are relatively more environmentally friendly and in line with the concept of sustainable development.

[0009] Furthermore, the supercapacitor protection circuit includes an anti-breakdown protection circuit, which includes a pressure storage resistor R1 and an AC contactor. The coil JC1 of the AC contactor is connected in parallel to the primary side of the rectifier transformer, and the normally open contact NO1 of the AC contactor and the pressure storage resistor R1 are connected to form a series branch, which is connected in parallel with the supercapacitor module C.

[0010] In the above scheme, the supercapacitor is prevented from breakdown by setting up an anti-breakdown protection circuit. Specifically: if there is no load in the charging circuit and only the supercapacitor is working, the voltage borne by the supercapacitor is likely to exceed its rated voltage, which may easily cause the supercapacitor to break down; therefore, the pressure tank resistor R1 is set as a load to form an anti-breakdown protection for the supercapacitor. However, the pressure tank resistor R1 cannot be continuously connected to the supercapacitor during the discharge phase, otherwise it will discharge the electricity of the supercapacitor; therefore, an AC contactor is set to perform on-off control, so that the pressure tank resistor R1 is only connected to the charging circuit when the power grid is powered (i.e. charging the supercapacitor).

[0011] Furthermore, the supercapacitor protection circuit includes a charging current limiting protection circuit, which includes a current limiting resistor R2, a DC contactor and a voltage dividing resistor R3, the voltage dividing resistor R3 and the coil JC2 of the DC contactor are connected to form a series branch, the series branch is connected to the supercapacitor module C to form a parallel branch, the parallel branch is connected in series with the current limiting resistor R2, and the normally open contact NO2 of the DC contactor is connected in parallel to both ends of the current limiting resistor R2.

[0012] In the above scheme, a charging current limiting protection circuit is set to limit the charging current to the supercapacitor so that it will not be too large. Specifically, the internal resistance of the supercapacitor before charging is very small and can be regarded as 0. Therefore, if charging is carried out, the charging current to the supercapacitor will be relatively large, especially at the moment of starting charging, which can be close to infinity in theory, which will damage the performance and life of the supercapacitor and affect the safety of the circuit. Therefore, by connecting a current limiting resistor R2 in series on the front side of the supercapacitor, the charging current to the supercapacitor can be controlled to achieve the purpose of protection. However, if the current limiting resistor R2 continues to work for a long time, it will have adverse effects such as large voltage drop and high heat generation; therefore, combined with the rule that the final stage of the supercapacitor's charging current is a nonlinear curve (that is, when the supercapacitor is gradually close to being fully charged, the charging current will gradually decrease to approach 0), it can be seen that the operation of the current limiting resistor R2 can be appropriately terminated when the charging current is reduced to an appropriate value; by setting the voltage dividing resistor R3 and the DC contactor, when the charging voltage of the supercapacitor reaches an appropriate value (the change in the charging voltage is related to the change in the charging current, and the charging current also reaches an appropriate value at this time), the current limiting resistor R2 is short-circuited to terminate its voltage dividing and current limiting work.

[0013] Furthermore, the voltage-dividing resistor R3 is an adjustable resistor.

[0014] In the above scheme, the resistance value of the voltage-dividing resistor R3 affects the voltage of the DC contactor short-circuiting the current-limiting resistor R2. Since it is not necessary to wait until the charging current of the supercapacitor is 0 to terminate the operation of the current-limiting resistor R2, the voltage-dividing resistor R3 is set as an adjustable resistor, so that the specific termination time can be flexibly and dynamically adjusted by the technician according to actual needs.

[0015] Furthermore, the supercapacitor module C is connected in series with the circuit breaker switch S1.

[0016] In the above scheme, the circuit breaker switch S1 is set to facilitate the disassembly and assembly of the supercapacitor, and the discharge of the supercapacitor can be controlled. Specifically: the circuit breaker switch S1 is in a closed state by default. When the power grid is disconnected, the supercapacitor can be prevented from discharging by disconnecting the circuit breaker switch S1, thereby achieving the effect of power conservation. When the supercapacitor needs to be used for power supply, the circuit breaker switch S1 can be closed.

[0017] Furthermore, the circuit structure also includes an insulation monitoring relay KJ, and the insulation monitoring relay KJ is connected in parallel with the DC feeder loop.

[0018] In the above scheme, by setting up the insulation monitoring relay KJ, it is possible to monitor whether a ground fault occurs and give timely indications and alarms, thereby ensuring the normal operation of the power cabinet and the electrical equipment connected to it, and helping to ensure the reliability and stability of the power supply system.

[0019] Furthermore, the primary side of the rectifier transformer forms a delta-connected winding, and the secondary side of the rectifier transformer forms a star-connected winding and a delta-connected winding, respectively.

[0020] In the above scheme, by setting up star-connected windings and delta-connected windings at the same time, the advantages of the two connection methods can be fully utilized, so that the rectifier transformer can better adapt to various complex power grid environments and load requirements, thereby helping to improve the operating efficiency and stability of the power supply system.

[0021] The beneficial effects achieved by the utility model are:

[0022] A power supply cabinet using a supercapacitor is provided. By setting a supercapacitor as an energy storage device, the battery method in the prior art is replaced, and the cabinet has the advantages of high power density, fast charging and discharging speed, long cycle life, not easily affected by ambient temperature, high safety, and environmental protection and pollution-free. In addition, by setting a supercapacitor protection circuit, the working effect and performance of the supercapacitor can be guaranteed. The utility model can ensure the good working effect of the power supply cabinet, thereby improving the reliability and stability of the power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the circuit structure connection in the power cabinet described in the embodiment of the utility model. DETAILED DESCRIPTION

[0024] To clearly illustrate the solution in the utility model, further description is given below in conjunction with the accompanying drawings:

[0025] Example 1

[0026] This embodiment provides a power supply cabinet using a supercapacitor, the power supply cabinet comprising a cabinet body and a circuit structure located inside the cabinet body; please refer to Figure 1The circuit structure includes a rectifier transformer, a supercapacitor module C and four DC feeder loops connected in sequence. The rectifier transformer is connected to the AC input end, and the DC feeder loop is connected to the load end. A supercapacitor protection circuit is also provided between the rectifier transformer and the supercapacitor module C. The supercapacitor protection circuit includes an anti-breakdown protection circuit and a charging current limiting protection circuit. Specifically:

[0027] The anti-breakdown protection circuit includes a pressure storage resistor R1 and an AC contactor. The coil JC1 of the AC contactor is connected in parallel to the primary side of the rectifier transformer. The normally open contact NO1 of the AC contactor and the pressure storage resistor R1 are connected to form a series branch, which is connected in parallel with the supercapacitor module C.

[0028] The charging current limiting protection circuit includes a current limiting resistor R2, a DC contactor and a voltage dividing resistor R3. The voltage dividing resistor R3, the normally open contact NO1 of the AC contactor, and the coil JC2 of the DC contactor are connected to form a series branch. The series branch is connected to the supercapacitor module C to form a parallel branch. The parallel branch is connected in series with the current limiting resistor R2 located on its front side, and the normally open contact NO2 of the DC contactor is connected in parallel to both ends of the current limiting resistor. Among them, the voltage dividing resistor R3 is an adjustable resistor.

[0029] In addition, the supercapacitor module C is connected in series with the circuit breaker switch S1 located in front of it; the circuit structure also includes an insulation monitoring relay KJ, which is connected in parallel with the DC feeder loop; the primary side of the rectifier transformer forms a triangle-connected winding, and the secondary side forms a star-connected winding and a triangle-connected winding respectively.

[0030] In this embodiment, the AC input terminal provides 380V AC power, and the DC feeder loop outputs 220V DC power; the electrical parameters of the supercapacitor module C are 432V, 7.5F, internal resistance 0.48Ω, the model of the AC contactor is CJ20-40 / AC380V, the model of the DC contactor is CJ0-100 / 10, the pressure chamber resistor R1 is 250Ω; 2kW enamel ceramic resistor, the current limiting resistor R2 is 6Ω; 10kW cast iron resistor, the voltage divider resistor R3 is 1500Ω; 2kW (adjustable).

[0031] Based on the above structure, the working principle of this embodiment is as follows:

[0032] The rectifier transformer rectifies the AC power provided by the AC input end and converts it into DC power output. The output DC power is used to charge the supercapacitor module C and directly power the DC feeder loop. If the AC input end stops providing AC power, the supercapacitor module C directly powers the DC feeder loop.

[0033] During the charging process of the supercapacitor module C, the anti-breakdown protection circuit is used to prevent the supercapacitor from breaking down, and the charging current limiting protection circuit is used to limit the charging current to the supercapacitor from being too large. Specifically:

[0034] If there is no load in the charging circuit and only the supercapacitor is working, the virtual voltage borne by the supercapacitor is likely to exceed its rated voltage, which can easily cause the supercapacitor to break down. In the anti-breakdown protection circuit, since the coil JC1 of the AC contactor is connected in parallel to the primary side of the rectifier transformer, when the power grid is in a power supply state, that is, when AC power is input to the rectifier transformer, the coil JC1 of the AC contactor will be energized, so that the normally open contact NO1 of the AC contactor is closed, thereby connecting the pressure tank resistor R1 to the charging circuit of the supercapacitor module C, so the pressure tank resistor R1, as a load, can form anti-breakdown protection for the supercapacitor. When the power grid is in a non-power supply state, that is, when there is no AC power input to the rectifier transformer, the coil JC1 of the AC contactor will lose power, so that the normally open contact NO1 of the AC contactor is restored and disconnected, thereby making the pressure tank resistor R1 no longer connected to the supercapacitor module C, thereby ensuring that the pressure tank resistor R1 will not discharge the electricity of the supercapacitor during the discharge stage.

[0035] The internal resistance of a supercapacitor before charging is very small and can be regarded as 0. Therefore, if charging is carried out, the charging current to the supercapacitor will be relatively large, especially at the beginning of charging, which can be regarded as close to infinity. This will damage the performance and life of the supercapacitor and affect the safety of the circuit. In the charging current limiting protection circuit, when AC power starts to be input to the AC input terminal, that is, after the supercapacitor module C is charged, the current limiting resistor R2 connected in series on the front side of the supercapacitor module C will perform voltage division and current limiting to reduce the charging current to the supercapacitor module C. At the same time, the voltage dividing resistor R3 and the coil JC2 of the DC contactor will be connected to the supercapacitor module C through the normally open contact NO1 of the closed AC contactor; the resistance value of the voltage dividing resistor R3 will be pre-adjusted to an appropriate value, and the coil JC2 of the DC contactor will be controlled to start when it reaches a preset voltage under the voltage dividing action of the voltage dividing resistor R3, so that after the charging progress of the supercapacitor module C reaches the set level, the DC contactor starts, thereby closing the normally open contact NO2 of the DC contactor to short-circuit the current limiting resistor R2, thereby terminating its voltage division and current limiting work. When there is no more AC input at the AC input end, the coil JC1 of the AC contactor loses pressure, and the normally open contact NO1 of the AC contactor is released and disconnected. The coil JC2 of the DC contactor will also lose pressure, causing the normally open contact NO2 of the DC contactor to be released and disconnected, thereby releasing the short circuit of the current limiting resistor R2, so that the current limiting resistor R2 can still perform the voltage division and current limiting work normally when charging next time.

[0036] In addition, the circuit breaker switch S1 is closed by default. When the power grid is disconnected, the supercapacitor can be prevented from discharging by disconnecting the circuit breaker switch S1, thereby achieving the effect of power conservation. When the supercapacitor is needed for power supply, the circuit breaker switch S1 can be closed. The insulation monitoring relay KJ can monitor whether there is a ground fault and give timely indications and alarms, thereby ensuring the normal operation of the power cabinet and the electrical equipment connected to it.

[0037] It should be noted that the parts that are not described in detail or in detail in the above scheme, such as the specific monitoring principle of the insulation monitoring relay KJ and the specific principle of rectification achieved by the rectifier transformer, are all existing technologies and do not belong to the improvements made by the present invention on the existing technology, nor do they belong to the scope of protection of the technical scheme of the present invention. Therefore, they will not be repeated in this article.

[0038] Of course, the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and any equivalent changes and improvements made by ordinary technicians in the technical field within the essential scope of the present invention shall fall within the scope of the patent coverage of the present invention.

Claims

1. A power supply cabinet using a supercapacitor, comprising a cabinet and a circuit structure located inside the cabinet, characterized in that: The circuit structure includes a rectifier transformer, a supercapacitor module C and a DC feeder loop connected in sequence, the rectifier transformer is connected to the AC input end, the DC feeder loop is connected to the load end, and a supercapacitor protection circuit is also provided between the rectifier transformer and the supercapacitor module C.

2. The power supply cabinet using supercapacitors according to claim 1 is characterized in that: The supercapacitor protection circuit includes an anti-breakdown protection circuit, which includes a pressure storage resistor R1 and an AC contactor. The coil JC1 of the AC contactor is connected in parallel to the primary side of the rectifier transformer. The normally open contact NO1 of the AC contactor and the pressure storage resistor R1 are connected to form a series branch, which is connected in parallel with the supercapacitor module C.

3. The power supply cabinet using supercapacitors according to claim 1 is characterized in that: The supercapacitor protection circuit includes a charging current limiting protection circuit, which includes a current limiting resistor R2, a DC contactor and a voltage dividing resistor R3. The voltage dividing resistor R3 and the coil JC2 of the DC contactor are connected to form a series branch, and the series branch is connected to the supercapacitor module C to form a parallel branch. The parallel branch is connected in series with the current limiting resistor R2, and the normally open contact NO2 of the DC contactor is connected in parallel to both ends of the current limiting resistor.

4. The power supply cabinet using supercapacitors according to claim 3 is characterized in that: The voltage dividing resistor R3 is an adjustable resistor.

5. The power supply cabinet using supercapacitors according to claim 1 is characterized in that: The supercapacitor module C is connected in series with the circuit breaker switch S1.

6. The power supply cabinet using supercapacitors according to claim 1, characterized in that: The circuit structure further includes an insulation monitoring relay KJ, and the insulation monitoring relay KJ is connected in parallel with the DC feeder loop.

7. The power supply cabinet using supercapacitors according to claim 1, characterized in that: The primary side of the rectifier transformer forms a delta connection winding, and the secondary side of the rectifier transformer forms a star connection winding and a delta connection winding respectively.

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