Electricity taking device

Abstract

The invention provides an electricity taking device. The electricity taking device comprises a voltage dividing module, a first transformer, a second transformer and a relay, the voltage division module is used for being connected with a power supply and carrying out voltage division processing on power supply voltage provided by the power supply to obtain input voltage; the relay is connected with the first transformer and the second transformer and used for controlling operation of the first transformer or the second transformer. The first transformer is connected with the voltage dividing module and is used for performing first voltage transformation processing on the input voltage in an operation state to obtain a first output voltage; the second transformer is connected with the voltage dividing module and is used for carrying out second voltage transformation processing on the input voltage in the operation state to obtain second output voltage. The first transformer and the second transformer are controlled to operate alternately through the relay, the voltage output by the power taking device can be adaptively adjusted, and the safety of the power taking device for supplying power to electric equipment is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrical equipment, and in particular to a power extraction device. Background Art

[0002] In the integrated primary and secondary pole-mounted circuit breaker, the power supply to the secondary equipment is provided by the power taking device. Specifically, the input voltage is transformed by the transformer in the power taking device, and then the transformed voltage is output to the secondary equipment. According to the national standard, the integrated primary and secondary pole-mounted circuit breaker needs to operate continuously for 1 minute at a voltage of 42 kilovolts (kV), and normal operation without damage is guaranteed during this period. The rated voltage of the secondary equipment is 27V. When the input voltage is 42kV, after the transformer in the power taking device transforms the voltage, the voltage output to the secondary equipment will reach 7.3 times the rated voltage, which can easily burn the secondary equipment. Summary of the invention

[0003] The embodiment of the present application provides a power supply device, which can control the alternating operation of a first transformer and a second transformer through a relay, adaptively adjust the voltage output by the power supply device, and improve the safety of the power supply device in supplying power to electrical equipment.

[0004] The technical solution of the embodiment of the present application is implemented as follows: The present application provides a power supply device, the device comprising: A voltage dividing module, a first transformer, a second transformer and a relay; the voltage dividing module is used to connect a power supply and perform voltage dividing processing on the power supply voltage provided by the power supply to obtain an input voltage; the relay is connected to the first transformer and the second transformer to control the operation of the first transformer or the second transformer; the first transformer is connected to the voltage dividing module to perform a first voltage transformation processing on the input voltage in a running state to obtain a first output voltage; the second transformer is connected to the voltage dividing module to perform a second voltage transformation processing on the input voltage in a running state to obtain a second output voltage.

[0005] The above-mentioned power taking device further includes: The voltage divider module includes: a first capacitor and a second capacitor; the first capacitor is used to connect the power supply and perform a first voltage division process on the power supply voltage provided by the power supply; the second capacitor is connected in series with the first capacitor and is used to perform a second voltage division process on the power supply voltage after the first voltage division process to obtain the input voltage.

[0006] The above-mentioned power taking device further includes: The first transformer includes a first primary winding and a first secondary winding, and the second transformer includes a second primary winding and a second secondary winding; the first primary winding is connected in parallel with the second capacitor for receiving the input voltage; the first secondary winding is connected with the relay for outputting the first output voltage; the second primary winding is connected in series or in parallel with the first primary winding for receiving the input voltage; the second secondary winding is connected in parallel with the first secondary winding and connected with the relay for outputting the second output voltage.

[0007] The above-mentioned power taking device further includes: The number of turns of the first primary winding is greater than the number of turns of the first secondary winding; the number of turns of the second primary winding is greater than the number of turns of the second secondary winding; the number of turns of the first primary winding is the same as the number of turns of the second primary winding; the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

[0008] The above-mentioned power taking device further includes: The relay includes: an electromagnet, a first switching element and a second switching element; the electromagnet is connected in parallel with the first secondary winding to control the closing and opening of the first switching element, and the closing and opening of the second switching element; the first switching element is connected in series with the first secondary winding to control the operation of the first transformer; the second switching element is connected in series with the second secondary winding to control the operation of the second transformer.

[0009] The above-mentioned power taking device further includes: When the first output voltage is less than a preset voltage threshold, the electromagnet controls the first switch element to close and controls the second switch element to open, so that the first transformer runs and the second transformer stops running; the input voltage is subjected to a first voltage transformation processing by the first transformer to obtain the first output voltage, and outputs it to the electrical equipment.

[0010] The above-mentioned power taking device further includes: When the first output voltage is greater than or equal to the voltage threshold, the electromagnet controls the first switch element to open and controls the second switch element to close, so that the second transformer runs and the first transformer stops running; the input voltage is subjected to a second voltage transformation by the second transformer to obtain the second output voltage, and outputs it to the electrical equipment.

[0011] The above-mentioned power taking device further includes: The ratio between the voltage threshold preset by the relay and the rated voltage of the electrical equipment is a first value; the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a second value; wherein the ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical equipment to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage. The above-mentioned power supply device also includes: The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a third value, and the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is the third value; wherein the third value is equal to the square root of the ratio between the standard voltage and the operating voltage.

[0012] The above-mentioned power taking device further includes: The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a fourth value, and the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; wherein, the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage, and is greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the operating voltage.

[0013] The embodiments of the present application have the following beneficial effects: The power taking device of the embodiment of the present application includes: a voltage dividing module, a first transformer, a second transformer and a relay. Among them, the voltage dividing module is used to connect the power supply, divide the power supply voltage provided by the power supply to obtain the input voltage, and the relay is connected to the first transformer and the second transformer. The relay can control the first transformer and the second transformer to operate alternately. In this way, when the voltage transformation capacity of the first transformer can meet the voltage transformation demand, the first transformer of the power taking device performs the first voltage transformation process on the input voltage, and the first output voltage output by the first transformer is used as the input voltage of the electrical equipment. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the demand, the second transformer is controlled to be put into operation through the relay, and the input voltage is subjected to the second voltage transformation process through the second transformer, so that the second output voltage output by the second transformer is reduced to the voltage range that the electrical equipment can bear, and the second output voltage is used as the input voltage of the electrical equipment to avoid burning of the electrical equipment. In this way, the present application controls the first transformer and the second transformer to operate alternately through the relay, and can adaptively adjust the voltage output by the power taking device, thereby improving the safety of the power taking device supplying power to the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the circuit structure of a power taking device in the related art; Figure 2This is a schematic diagram of an optional circuit structure of a power extraction device provided in an embodiment of the present application; Figure 3 This is another optional circuit structure diagram of the power extraction device provided in the embodiment of the present application; Figure 4 is a schematic diagram of the circuit structure of the power taking device provided in an embodiment of the present application when the first transformer is in operation; Figure 5 It is a schematic diagram of the circuit structure of the power taking device provided in an embodiment of the present application when the second transformer is in operation. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0016] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0017] In the following description, the terms "first\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0018] Unless otherwise defined, all technical and scientific terms used in the embodiments of the present application have the same meanings as those commonly understood by those skilled in the art. The terms used in the embodiments of the present application are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0019] Before further describing the embodiments of the present application in detail, the nouns and terms involved in the embodiments of the present application are explained. The nouns and terms involved in the embodiments of the present application are subject to the following interpretations.

[0020] 1) Primary and secondary integrated pole-mounted circuit breaker: a pole-mounted switchgear that combines distribution automation technology. "Primary and secondary integration" refers to the design that integrates primary equipment (main circuit equipment, such as circuit breakers) and secondary equipment (auxiliary equipment such as control, protection, and monitoring) into one.

[0021] 2) Power extraction device: A device that can extract energy from a specific environment and convert it into usable electrical energy, usually used to provide power for various monitoring equipment, sensors or remote communication equipment. The power extraction device in this application is a power extraction device in a primary and secondary integrated pole-mounted circuit breaker, which is used to provide power for secondary equipment. It can extract energy from the primary system to power secondary equipment such as protection relays, communication modules, automation devices, etc.

[0022] 3) Transformer: A stationary electrical device that is mainly used to change the size of AC voltage, and can increase or decrease the voltage as needed. The working principle of the transformer is based on electromagnetic induction, that is, when AC current passes through the primary coil (main coil), a voltage is generated in the secondary coil (secondary coil).

[0023] 4) Rated voltage: The voltage value specified when the equipment or system is designed, indicating the voltage that the equipment should withstand under normal working conditions.

[0024] 5) Minimum operating voltage: The lowest voltage value at which a device or electronic component can start normally and continue to work. It is one of the device design parameters, ensuring that the device can operate stably above this voltage value without performance degradation or failure to start due to low voltage.

[0025] 6) KA AC relay: A commonly used electromagnetic relay whose working principle is to use electromagnetic attraction to control the on and off of the circuit, where "KA" represents a model.

[0026] 7) High-voltage capacitor: A type of capacitor whose main feature is the ability to withstand higher voltages. Usually, its rated voltage is above 1kV. It is used for power factor compensation, voltage stabilization and harmonic filtering in high-voltage environments to improve the operating efficiency and stability of the power system.

[0027] 8) Low-voltage capacitors: usually refers to power capacitors with rated voltages ranging from 400 volts (V) to 6kV, which can provide capacitive reactive power to compensate for the reactive power caused by inductive loads (such as motors, transformers, etc.), thereby improving the power factor of the system and reducing the transmission of reactive power.

[0028] It should be noted that the low-voltage capacitor and high-voltage capacitor involved in the embodiments of the present application are two relative concepts. Specifically, the power-taking device in the present application includes at least a first capacitor and a second capacitor, wherein the first capacitor is connected to the high-voltage end and carries a relatively high voltage, and the second capacitor carries a relatively low voltage. For ease of explanation, in the embodiments of the present application, the high-voltage capacitor is referred to as the first capacitor, and the low-voltage capacitor is referred to as the second capacitor.

[0029] In the related art, the power taking device in the primary and secondary integrated pole-mounted circuit breaker is only one transformer. Figure 1, Figure 1 It is a schematic diagram of the circuit structure of the power-taking device in the related art. Among them, the positive electrode of the high-voltage capacitor 101 is used to connect the power supply, and the negative electrode is connected to the positive electrode of the low-voltage capacitor 102, so that the high-voltage capacitor 101 is connected in series with the low-voltage capacitor 102, and the negative electrode of the low-voltage capacitor 102 is used for grounding. The inductor 103 is connected in parallel with the low-voltage capacitor 102. The transformer 104 includes a primary winding 1041 and a secondary winding 1042. The primary winding 1041 is connected in series with the inductor 103, and the secondary winding 1042 is used to connect other devices. Under normal circumstances, the voltage output by the power supply 101 is 5.7kV, that is, the input voltage of the power-taking device is 5.7kV. After the transformer 104 is transformed, the power-taking device can output a voltage of 27V (the rated voltage of the electrical equipment) and output it to the secondary equipment. According to the national standard requirements, the primary and secondary integrated pole-mounted circuit breaker must meet the requirements of continuous operation at a voltage of 42kV for 1 minute, and ensure normal operation without damage during the period. Therefore, the input voltage of the power taking device needs to be gradually increased from 5.7kV to 42kV. When the input voltage increases to 42kV, the output voltage of the transformer 104 will increase to 7.3 times the rated voltage of the secondary equipment (ie 27V), which far exceeds the rated voltage of the secondary equipment and can easily burn the secondary equipment.

[0030] Based on the above-mentioned problems existing in the related art, an embodiment of the present application provides a power supply device, which can perform a first voltage transformation process on the input voltage through the first transformer of the power supply device when the voltage transformation capacity of the first transformer meets the voltage transformation demand, and use the first output voltage output by the first transformer as the input voltage of the electrical equipment. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the voltage transformation demand, the second transformer is controlled to be put into operation through a relay, and the input voltage is subjected to a second voltage transformation process through the second transformer, so that the second output voltage output by the second transformer is reduced to within the voltage range that the electrical equipment can withstand, and the second output voltage is used as the input voltage of the electrical equipment to avoid burning of the electrical equipment. In this way, the embodiment of the present application controls the alternating operation of the first transformer and the second transformer through a relay, and can adaptively adjust the voltage output by the power supply device, thereby improving the safety of the power supply device for the electrical equipment.

[0031] See also Figure 2 , Figure 2 This is an optional circuit structure diagram of the power extraction device provided in the embodiment of the present application. Figure 2 The circuit structure shown is explained.

[0032] In some embodiments, the power supply device includes a voltage divider module 201, a first transformer 202, a second transformer 203 and a relay 204; the voltage divider module 201 is used to connect a power supply and perform voltage division processing on the power supply voltage provided by the power supply to obtain an input voltage; the relay 204 is connected to the first transformer 202 and the second transformer 203, and is used to control the operation of the first transformer 202 or the second transformer 203; the first transformer 202 is connected to the voltage divider module 201, and is used to perform a first voltage transformation processing on the input voltage in the operating state to obtain a first output voltage; the second transformer 203 is connected to the voltage divider module 201, and is used to perform a second voltage transformation processing on the input voltage in the operating state to obtain a second output voltage.

[0033] Here, the relay 204 is a KA AC relay, which is used to control the alternating operation of the first transformer 202 and the second transformer 203 according to the size of the first output voltage. The first transformer 202 and the second transformer 203 can perform different degrees of transformation processing on the input voltage, and the transformation processing includes increasing or decreasing the input voltage. The first output voltage and the second output voltage are used as input voltages of the electrical equipment. Taking the application of the power taking device to a primary and secondary integrated pole-mounted circuit breaker as an example, the electrical equipment is a secondary device. In actual applications, the power supply outputs the power supply voltage to the voltage dividing module 201, and the voltage dividing module 201 divides the power supply voltage to obtain the input voltage, and outputs the input voltage to the first transformer 202 or the second transformer 203. The relay 204 controls the operation of the first transformer 202 or the second transformer 203 according to the size of the input voltage. Then, the first transformer 202 performs a first transformation processing on the input voltage to obtain a first output voltage and output it to the secondary device; or, the second transformer 204 performs a second transformation processing on the input voltage to obtain a second output voltage and output it to the secondary device.

[0034] In the embodiment of the present application, the alternating operation of the first transformer and the second transformer is realized by controlling the relay. When the voltage transformation capacity of the first transformer can meet the voltage transformation demand, the first transformer of the power taking device performs the first voltage transformation processing on the input voltage, and the first output voltage output by the first transformer is used as the input voltage of the power-consuming device. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the demand, the second transformer is controlled to be put into operation through the relay, and the second transformer performs the second voltage transformation processing on the input voltage, so that the second output voltage output by the second transformer is reduced to the voltage range that the power-consuming device can bear, and the second output voltage is used as the input voltage of the power-consuming device, so as to avoid the burning of the power-consuming device and improve the safety of the power taking device supplying power to the power-consuming device.

[0035] In some embodiments, see Figure 2The voltage dividing module 201 includes a first capacitor 11 and a second capacitor 12. The first capacitor 11 is connected to a power supply and is used to perform a first voltage dividing process on the power supply voltage provided by the power supply; the second capacitor 12 is connected in series with the first capacitor 11 and is used to perform a second voltage dividing process on the power supply voltage after the first voltage dividing process to obtain an input voltage.

[0036] Here, the first capacitor 11 is a high-voltage capacitor, and the second capacitor 12 is a low-voltage capacitor. Low-voltage capacitor and high-voltage capacitor are two relative concepts. "High voltage" refers to the part with a higher voltage level in the power system, usually above 1KV, and "low voltage" refers to the part with a lower voltage level in the power system, usually below 1KV. The positive pole of the first capacitor 11 is connected to the power supply, and the negative pole is connected to the second capacitor 12. The positive pole of the second capacitor 12 is connected to the negative pole of the first capacitor 11, and the negative pole of the second capacitor 12 is grounded. The first capacitor 11 performs a first voltage division process on the power supply voltage provided by the power supply and outputs it to the second capacitor 12. The second capacitor 12 receives the power supply voltage after the first voltage division process output by the first capacitor 11, and performs a second voltage division process to obtain the input voltage.

[0037] In the embodiment of the present application, the series combination of high-voltage capacitors and low-voltage capacitors can improve the energy storage capacity, voltage regulation capability, system protection capability and operating range of the power-taking device, thereby improving the overall performance and reliability of the system when the power-taking device is applied to the system.

[0038] In some embodiments, see Figure 2 The first transformer 202 includes a first primary winding 21 and a first secondary winding 22, and the second transformer 203 includes a second primary winding 31 and a second secondary winding 32; the first primary winding 21 is connected in parallel with the second capacitor 12 for receiving an input voltage; the first secondary winding 22 is connected to the relay 204 for outputting a first output voltage; the second primary winding 31 is connected in parallel with the first primary winding 21 for receiving an input voltage; the second secondary winding 32 is connected in parallel with the first secondary winding 22 and connected to the relay 204 for outputting a second output voltage.

[0039] Here, the winding is the core part of the transformer to achieve power transmission. The winding is usually wound with copper or aluminum wire. The primary winding is the winding connected to the input power supply, which is used to receive the power provided by the external power supply. The secondary winding is the winding connected to the load, which is used to output the power converted by the transformer. Among them, the first primary winding 21 and the second primary winding 31 are connected to the power supply as input terminals; the second primary winding 31 and the second secondary winding 32 are connected to the load (i.e., the electrical equipment) as output terminals. Taking the application of the power taking device to the primary and secondary integrated pole-mounted circuit breaker as an example, the load is the secondary equipment. The second primary winding 31 is connected in parallel with the first primary winding 21 to ensure that the input voltages of the first transformer 202 and the second transformer 203 are equal. The relay 204 is connected to the first secondary winding 22 and the second secondary winding 32, and can control whether the circuit between the first transformer 202 and the second transformer 203 and the electrical equipment is connected, thereby controlling the first transformer 202 and the second transformer 203 to be put into operation or enter the no-load state.

[0040] In some possible implementations, see Figure 3 , Figure 3 It is another optional circuit structure diagram of the power taking device provided in the embodiment of the present application. Among them, the first primary winding 301 is connected in series with the second primary winding 302. Here, when the specifications and parameters of the two transformers are consistent and the coil process meets the standards, the first transformer and the second transformer can be connected in parallel by connecting the primary windings of the first transformer and the second transformer in series and connecting the secondary windings of the first transformer and the second transformer in parallel.

[0041] In an embodiment of the present application, the first transformer and the second transformer are connected in parallel by connecting the primary windings of the two transformers in series or in parallel and the secondary windings in parallel. In this way, the input voltages of the primary windings of the two transformers are equal, which facilitates the alternating operation of the first transformer and the second transformer.

[0042] In some embodiments, the number of turns of the first primary winding is greater than the number of turns of the first secondary winding, the number of turns of the second primary winding is greater than the number of turns of the second secondary winding, the number of turns of the first primary winding is the same as the number of turns of the second primary winding, and the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

[0043] Here, the number of turns of the primary winding refers to the number of turns of the conductor in the coil wound on the primary side (primary) of the transformer, and the number of turns of the secondary winding refers to the number of turns of the conductor in the coil wound on the secondary side (secondary) of the transformer. The ratio of the number of turns of the primary winding to the number of turns of the secondary winding determines the ratio between the input voltage and the output voltage. If the number of turns of the primary winding is greater than the number of turns of the secondary winding, then the ratio of the number of turns of the primary winding to the number of turns of the secondary winding is greater than 1, that is, the ratio between the input voltage and the output voltage is greater than 1, that is, the transformer is a step-down transformer. In the embodiment of the present application, since the number of turns of the first primary winding is greater than the number of turns of the first secondary winding, and the number of turns of the second primary winding is greater than the number of turns of the second secondary winding, the first transformer and the second transformer are both step-down transformers. For a step-down transformer, when the number of turns of the primary winding is the same, the fewer the number of turns of the secondary winding, the greater the step-down capacity of the transformer. Since the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding, the step-down capacity of the second transformer is greater than the step-down capacity of the first transformer. For example, the first transformer can step down a voltage of 9V to 6V, and the second transformer can step down a voltage of 9V to 2V.

[0044] In the embodiment of the present application, the voltage reduction capability of the second transformer is made greater than that of the first transformer by controlling the number of turns of the secondary winding. In this way, when the voltage transformation capability of the first transformer can meet the voltage transformation requirement, the first transformer with low voltage reduction capability performs a first voltage transformation on the input voltage to obtain a first output voltage. When the input voltage increases and the voltage transformation capability of the first transformer is insufficient, the second transformer performs a second voltage transformation with a stronger voltage reduction effect on the input voltage, thereby strengthening the reduction of the output voltage of the power taking device and improving the safety of the power taking device in supplying power to the electrical equipment.

[0045] In some embodiments, see Figure 2 The relay 204 includes: an electromagnet 43, a first switch element 41 and a second switch element 42; the electromagnet is connected in parallel with the first secondary winding 22 to control the closing and opening of the first switch element 41, and the closing and opening of the second switch element 42; the first switch element 41 is connected in series with the first secondary winding 22 to control the operation of the first transformer 202; the second switch element 42 is connected in series with the second secondary winding 32 to control the operation of the second transformer 203.

[0046] Here, the first switch element 41 and the second switch element 42 are two independent switches, each of which has an independent armature, and the closing and opening of the switch are controlled by the position of the armature. It should be noted that in the embodiment of the present application, only one of the first switch element 41 and the second switch element 42 can be in a closed state. That is, the first switch element 41 is closed and the second switch element 42 is opened; or, the first switch element 41 is opened and the second switch element 42 is closed. The electromagnet 43 can convert electrical energy into mechanical energy. When the current passes through the coil of the electromagnet 43, a magnetic field is generated around it. The magnetic field can attract the armatures in the first switch element 41 and the second switch element 42, so that the position of the armature changes, thereby controlling the first switch element 41 and the second switch element 42 to close or open. The closing of the first switch element 41 can connect the circuit of the first transformer 202, thereby putting the first transformer 202 into operation; the closing of the second switch element 42 can connect the circuit of the second transformer 203, thereby putting the second transformer 203 into operation.

[0047] In the embodiment of the present application, the relay includes an electromagnet, a first switch element, and a second switch element. The electromagnet automatically controls the first switch element and the second switch element according to the received first input voltage, thereby controlling the operation of the first transformer or the second transformer. Therefore, the relay can realize the operation of the corresponding transformer adaptively switched according to the first input voltage, thereby improving the flexibility of the power taking device.

[0048] In some embodiments, see Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of the power taking device provided in the embodiment of the present application when the first transformer is in operation. When the first output voltage is less than the preset voltage threshold, the electromagnet 403 controls the first switch element 401 to close and controls the second switch element 402 to open, so that the first transformer 404 operates and the second transformer 405 stops operating; the first transformer 404 performs a first voltage transformation on the input voltage to obtain a first output voltage, which is then output to the power-consuming device.

[0049] Here, the preset voltage threshold is also referred to as the breaking voltage or disconnecting voltage of the relay, and the preset voltage threshold enables the electromagnet 403 to generate sufficient suction force to attract the armature. When the first output voltage is less than the preset voltage threshold, the electromagnet magnetic force cannot attract the armature to change its position, and the armature is in the default position. At this time, the first switch element 401 is closed and the second switch element 402 is disconnected; when the first output voltage is greater than the preset voltage threshold, the electromagnet magnetic force is enhanced, and the armature will change its position under the influence of the magnetic attraction force. At this time, the first switch element 401 is disconnected and the second switch element 402 is closed. That is to say, when the first output voltage is less than the preset voltage threshold, the armature control switch of the first switch element 401 is closed, the circuit between the first transformer and the electrical equipment is connected, the first transformer is put into operation, the input voltage is subjected to the first voltage transformation process, the first output voltage is obtained and output to the electrical equipment; the armature control switch of the second switch element 402 is disconnected, the circuit between the second transformer and the electrical equipment is disconnected, and the circuit enters the no-load state and stops running.

[0050] In the embodiment of the present application, the electromagnet in the relay can control the closing and opening of the first switch element and the second switch element according to the first output voltage of the first voltage generator, thereby controlling the operation of the first transformer or the second transformer. When the first output voltage is less than the preset voltage threshold, the voltage reduction capacity of the first transformer meets the demand, the first transformer operates, and the power taking device normally supplies power to the power-consuming equipment, thereby ensuring the stable operation of the power taking device.

[0051] In some embodiments, see Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of the power taking device provided in the embodiment of the present application when the second transformer is in operation. When the first output voltage is greater than or equal to the voltage threshold, the electromagnet 503 controls the first switch element 501 to be disconnected, and controls the second switch element 502 to be closed, so that the second transformer 505 is in operation and the first transformer 504 stops operating; the second transformer 505 performs a second voltage transformation on the input voltage to obtain a second output voltage, and outputs it to the power-consuming device.

[0052] Here, when the first output voltage is greater than the preset voltage threshold, the armature of the first switch element 501 is attracted by the magnetic force of the electromagnet 503 and moves to a position where the first switch element 501 is disconnected, and the armature of the second switch element 502 is attracted by the magnetic force of the electromagnet 503 and moves to a position where the second switch element 502 is closed. Since the first switch element 501 is connected in series with the first secondary winding of the first transformer, the first switch element 501 is disconnected to disconnect the circuit between the first secondary winding and the electrical device, and the first transformer stops running. The second switch element 502 is connected in series with the second secondary winding of the second transformer, so the second switch element 502 is closed to connect the circuit between the second secondary winding and the electrical device, and the second transformer performs a second transformation on the input voltage to obtain a second output voltage, and outputs it to the electrical device.

[0053] It should be noted that the first switch element 501 and the second switch element 502 have a reset function, that is, when the first output voltage decreases from greater than a preset voltage threshold to less than a preset voltage threshold, the armatures in the first switch element 501 and the second switch element 502 will return to a default state, that is, the first switch element 501 is closed again, and the second switch element 502 is opened again. Specifically, the reset function of the armature can be achieved by adding a spring to the armature part.

[0054] In the embodiment of the present application, when the first output voltage is greater than the preset voltage threshold, the voltage reduction capacity of the first transformer cannot meet the demand. If the first output voltage output by the first transformer continues to be used to power the electrical equipment, it may cause the electrical equipment to burn out due to overvoltage. Therefore, the operation of the second transformer is controlled by a relay, and the voltage reduction capacity of the second transformer is greater than that of the first transformer. Therefore, the voltage output by the power taking device can be reduced to a voltage range that the electrical equipment can withstand through the second transformer, thereby avoiding the electrical equipment from burning out, thereby improving the safety of the power taking device supplying power to the electrical equipment.

[0055] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a first value; the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a second value; wherein the ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical equipment to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage.

[0056] Here, standard voltage refers to the voltage value that the equipment needs to withstand according to the national standard. Operating voltage refers to the input voltage of the power-taking device when the first output voltage is equal to the rated voltage of the electrical equipment, that is, after the operating voltage is transformed by the first transformer, the output first output voltage is the rated voltage of the electrical equipment. The rated voltage of the electrical equipment refers to the standard working voltage specified when the equipment is designed, that is, the voltage value that the equipment should be connected to when it is running under optimal performance and safety. The minimum actual voltage of the electrical equipment refers to the lowest voltage level at which the equipment can work normally. The rated voltage and the minimum actual voltage are determined by the equipment manufacturer based on the electrical characteristics and use environment of the equipment, and are usually indicated on the nameplate or manual of the equipment. It should be noted that in the actual setting process, the calculation results of multiple data usually include multiple digits after the decimal point. In order to facilitate the setting of the parameters of each component, the approximate value of the actual calculation result is usually selected as the final calculation result. For example, the actual calculation result is 8.35967, and its approximate value 8.4 is taken as the final calculation result.

[0057] Take the power-taking device applied to the primary and secondary integrated pole-mounted circuit breaker as an example. According to the national standard requirements, the standard voltage is 42kV; the power-consuming equipment is the secondary equipment, the rated voltage is 27V, and the minimum actual voltage is 85% of the rated voltage; when the input voltage of the power-taking device is 5.7kV, the first output voltage of the first transformer is 27V, so the operating voltage is 5.7kV. X represents the first value, Y represents the second value, N1 represents the number of turns of the first secondary winding of the first transformer, and N2 represents the number of turns of the second secondary winding of the second transformer. Then, the voltage threshold preset by the relay is equal to X×27V, N1 / N2=Y, X / Y=0.85, XY=42kV / 5.7kV≈7.3. After calculation, it is found that X=2.49, Y=2.93. That is, the voltage threshold preset by the relay is 2.49 times the rated voltage of the power-consuming equipment, and the turn ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is 2.93. In this way, the voltage of the electrical equipment is equal from the moment before the first switching element is disconnected to the period when the input voltage reaches 42kV and lasts for one minute; at the moment when the first switching element is disconnected and the second switching element is closed, the voltage of the electrical equipment drops instantaneously from 2.49 times the rated voltage to 0.85 times the rated voltage; therefore, the minimum voltage of the electrical equipment is 85% of the rated voltage, and the maximum voltage is 2.49 times the rated voltage.

[0058] Through the embodiments of the present application, the maximum voltage that the electrical equipment needs to withstand can be reduced to the minimum value while meeting the minimum actual voltage of the electrical equipment, thereby protecting the electrical equipment and improving the safety of the power supply device to the electrical equipment.

[0059] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a third value, and the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a third value; wherein the third value is equal to the square root of the ratio between the standard voltage and the operating voltage.

[0060] Here, it is also necessary to explain that in the actual setting process, the calculation results of multiple data usually include multiple digits after the decimal point. In order to facilitate the setting of the parameters of each component, the approximate value of the actual calculation result is selected as the final calculation result. Taking the power-taking device applied to the primary and secondary integrated pole-mounted circuit breaker as an example, according to the national standard requirements, the standard voltage is 42kV; the power-consuming equipment is a secondary equipment, the rated voltage of the secondary equipment is 27V, and the minimum actual voltage is 85% of the rated voltage; when the input voltage of the power-taking device is 5.7kV, the first output voltage of the first transformer is 27V, that is, the operating voltage is 5.7kV. Therefore, the third value is equal to the square root of 42kV / 27V, which is approximately equal to 2.7. Therefore, the preset voltage threshold of the relay is 2.7×27V, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is 2.7. In this way, in actual operation, the minimum voltage of the power-consuming equipment is not lower than the rated voltage, and the maximum withstand voltage is 2.7 times the rated voltage.

[0061] Through the embodiments of the present application, the maximum voltage that the electrical equipment needs to withstand can be minimized while ensuring that the minimum voltage of the electrical equipment is not lower than the rated voltage, thereby improving the safety of the power supply provided by the power taking device to the electrical equipment.

[0062] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a fourth value, and the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; wherein the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage, and is greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the rated voltage.

[0063] Here, the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage, and the difference between the fourth value and the square root of the ratio between the standard voltage and the operating voltage is usually no more than 1. The fifth value is greater than the square root of the ratio between the standard voltage and the rated voltage, and the difference between the fifth value and the square root of the ratio between the standard voltage and the operating voltage is usually no more than 1. It should also be noted that in the actual setting process, the calculation results of multiple data usually include multiple digits after the decimal point. In order to facilitate the setting of the parameters of each component, the approximate value of the actual calculation result is selected as the final calculation result. Taking the power-taking device applied to the primary and secondary integrated pole-mounted circuit breaker as an example, according to the national standard requirements, the standard voltage is 42kV; the power-consuming equipment is a secondary device, the rated voltage of the secondary device is 27V, and the minimum actual voltage is 85% of the rated voltage; when the input voltage of the power-taking device is 5.7kV, the first output voltage of the first transformer is 27V, that is, the operating voltage is 5.7kV. Therefore, the square root of the ratio between the standard voltage and the operating voltage is the square root of 42kV / 27V, which is approximately equal to 2.7. Therefore, 0<fourth value<2.7, can be set to 2.5; fifth value is greater than 2.7, can be set to 3. In this way, before the first switch element is disconnected, the voltage of the electrical device is 2.4999... times the rated voltage. At the moment when the first switch element is disconnected and the second switch element is closed, the voltage of the electrical device is 2.5 / 3 times the rated voltage, which is slightly lower than the rated voltage. During the period when the power supply voltage lasts for one minute at 42kV, the voltage of the electrical device is 2.4 times the rated voltage.

[0064] In the embodiment of the present application, when the voltage of the electrical equipment is slightly lower than the rated voltage for a period of time, the maximum voltage that the electrical equipment needs to withstand can be reduced as much as possible, thereby improving the safety of the power supply provided by the power taking device to the electrical equipment.

[0065] In summary, in an embodiment of the present application, when the voltage transformation capacity of the first transformer can meet the voltage transformation demand, the first transformer of the power taking device performs a first voltage transformation on the input voltage, and the first output voltage output by the first transformer is used as the input voltage of the electrical equipment. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the demand, the second transformer is controlled to be put into operation through a relay, and the second transformer performs a second voltage transformation on the input voltage, so that the second output voltage output by the second transformer is reduced to a voltage range that the electrical equipment can withstand, and the second output voltage is used as the input voltage of the electrical equipment to avoid burning of the electrical equipment. In this way, the present application controls the alternating operation of the first transformer and the second transformer through a relay, and can adaptively adjust the voltage output by the power taking device, thereby improving the safety of the power taking device supplying power to the electrical equipment.

[0066] The above is only an embodiment of the present application and is not intended to limit the protection scope of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and scope of the present application are included in the protection scope of the present application.

Claims

1. A power extraction device, characterized in that: The device comprises: a voltage dividing module, a first transformer, a second transformer and a relay; The voltage dividing module is used to connect to a power supply and divide the power supply voltage provided by the power supply to obtain an input voltage; The relay is connected to the first transformer and the second transformer, and is used to control the operation of the first transformer or the second transformer; The first transformer is connected to the voltage dividing module and is used to perform a first voltage transformation on the input voltage in a running state to obtain a first output voltage; The second transformer is connected to the voltage dividing module and is used to perform a second voltage transformation on the input voltage in a running state to obtain a second output voltage.

2. The power extraction device according to claim 1, characterized in that: The voltage dividing module includes: a first capacitor and a second capacitor; The first capacitor is used to connect to the power supply and perform a first voltage division process on the power supply voltage provided by the power supply; The second capacitor is connected in series with the first capacitor and is used to perform a second voltage division process on the power supply voltage after the first voltage division process to obtain the input voltage.

3. The power extraction device according to claim 2, characterized in that: The first transformer comprises a first primary winding and a first secondary winding, and the second transformer comprises a second primary winding and a second secondary winding; The first primary winding is connected in parallel with the second capacitor and is used to receive the input voltage; The first secondary winding is connected to the relay and is used to output the first output voltage; The second primary winding is connected in series or in parallel with the first primary winding, and is used to receive the input voltage; The second secondary winding is connected in parallel with the first secondary winding and is connected to the relay for outputting the second output voltage.

4. The power extraction device according to claim 3, characterized in that: The number of turns of the first primary winding is greater than the number of turns of the first secondary winding; The number of turns of the second primary winding is greater than the number of turns of the second secondary winding; The number of turns of the first primary winding is the same as the number of turns of the second primary winding; The number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

5. The power extraction device according to claim 3, characterized in that: The relay comprises: an electromagnet, a first switching element and a second switching element; The electromagnet is connected in parallel with the first secondary winding and is used to control the closing and opening of the first switch element and the closing and opening of the second switch element; The first switch element is connected in series with the first secondary winding and is used to control the operation of the first transformer; The second switch element is connected in series with the second secondary winding and is used to control the operation of the second transformer.

6. The power extraction device according to claim 5, characterized in that: When the first output voltage is less than a preset voltage threshold, the electromagnet controls the first switch element to close and controls the second switch element to open, so that the first transformer operates and the second transformer stops operating; The first transformer performs a first voltage transformation on the input voltage to obtain the first output voltage, and outputs the first output voltage to the electrical equipment.

7. The power extraction device according to claim 6, characterized in that: When the first output voltage is greater than or equal to the voltage threshold, the electromagnet controls the first switch element to be disconnected, and controls the second switch element to be closed, so that the second transformer operates and the first transformer stops operating; The second transformer performs a second transformation process on the input voltage to obtain the second output voltage, and outputs the second output voltage to the electrical device.

8. The power extraction device according to any one of claims 1 to 7, characterized in that: The ratio between the voltage threshold preset by the relay and the rated voltage of the electrical equipment is a first value; a turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer being a second value; The ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical equipment to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage.

9. The power extraction device according to any one of claims 1 to 7, characterized in that: The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a third value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is the third value; The third value is equal to the square root of the ratio between the standard voltage and the operating voltage.

10. The power extraction device according to any one of claims 1 to 7, characterized in that: The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a fourth value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; The fourth value is smaller than the square root of the ratio between the standard voltage and the operating voltage and is greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the operating voltage.

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