Voltage conversion circuit, magnetically controlled circuit breaker control circuit and feeder terminal

Abstract

The invention is suitable for the technical field of power supply control, and provides a voltage conversion circuit, a magnetic control circuit breaker control circuit and a feeder terminal, the voltage conversion circuit comprises a plurality of capacitors which are connected in sequence through a relay; the first switch of each relay is connected with the anode of the previous capacitor, and the second switch of each relay is connected with the cathode of the next capacitor; the normally-closed contact of the first switch is connected with the positive electrode of the next capacitor, and the normally-closed contact of the second switch is connected with the negative electrode of the previous capacitor. Normally open contacts of the first switch and the second switch are in short circuit; a coil of each relay is used for connecting a driving control circuit; the anode of the first capacitor is also used for connecting the anode of a charging power supply, and the cathode of the first capacitor is also used for connecting the cathode of the charging power supply and the cathode of the magnetically controlled circuit breaker; and the positive pole of the last capacitor is also used for connecting the positive pole of the magnetically controlled circuit breaker. The problem that the feeder terminal is difficult to meet the action voltage of the magnetically controlled circuit breaker can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply control, and in particular relates to a voltage conversion circuit, a magnetically controlled circuit breaker control circuit and a feeder terminal. Background Art

[0002] Feeder Terminal Unit (FTU) is an intelligent terminal device installed in the distribution room or feeder. It can communicate with the remote distribution substation, send the operation data of the distribution equipment to the distribution substation, and receive the control command of the distribution substation to control and adjust the distribution equipment.

[0003] The feeder terminal achieves rapid disconnection through a magnetically controlled circuit breaker. The external voltage of the secondary feeder terminal in the distribution network is generally 24V, while the operating voltage of a general magnetically controlled circuit breaker is around several hundred volts. When the secondary feeder terminal is used in conjunction with a magnetically controlled switch, it is difficult to meet the operating voltage of the magnetically controlled circuit breaker. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a voltage conversion circuit, a magnetically controlled circuit breaker control circuit and a feeder terminal to solve the problem that the feeder terminal is difficult to meet the operating voltage of the magnetically controlled circuit breaker.

[0005] A first aspect of an embodiment of the present invention provides a voltage conversion circuit, comprising: a plurality of capacitors, wherein the plurality of capacitors are sequentially connected via a relay;

[0006] The first switch of each relay is connected to the positive electrode of the previous capacitor, and the second switch of each relay is connected to the negative electrode of the next capacitor; the normally closed contact of the first switch is connected to the positive electrode of the next capacitor, and the normally closed contact of the second switch is connected to the negative electrode of the previous capacitor; the normally open contacts of the first switch and the second switch are short-circuited; the coil of each relay is used to connect to the drive control circuit;

[0007] The positive electrode of the first capacitor is also used to connect the positive electrode of the charging power source, and the negative electrode of the first capacitor is also used to connect the negative electrode of the charging power source and the negative electrode of the magnetically controlled circuit breaker;

[0008] The positive terminal of the last capacitor is also used to connect the positive terminal of the magnetically controlled circuit breaker.

[0009] In combination with the first aspect, in a possible implementation manner of the first aspect, the number of the capacitors and the relays is determined according to the following method:

[0010]

[0011] Z = Y-1;

[0012] Wherein, Y is the number of the capacitors; S is the action voltage required for the magnetically controlled circuit breaker to operate; X is the charging voltage of the charging power supply; and Z is the number of the relays.

[0013] In combination with the first aspect, in a possible implementation manner of the first aspect, a parameter of the capacitor satisfies the following conditions:

[0014] A*Y>S;

[0015] B*Y>H;

[0016] Among them, A is the rated voltage value of the capacitor; B is the capacitance of the capacitor; S is the action voltage required for the magnetically controlled circuit breaker to operate; Y is the number of the capacitors; and H is the capacitance required for the magnetically controlled circuit breaker to operate.

[0017] In combination with the first aspect, in a possible implementation of the first aspect, the voltage of the charging power supply is 24V; the number of the capacitors is 13; the number of the relays is 12; the rated voltage of the capacitor is 2.7V, and the capacitance is 1F.

[0018] A second aspect of an embodiment of the present invention provides a magnetically controlled circuit breaker control circuit, comprising: a drive control circuit and a voltage conversion circuit as described in the first aspect or any one of the implementations of the first aspect;

[0019] The drive control circuit comprises: a control chip, a triode and a control relay;

[0020] The control end of the transistor is connected to the control chip, the output end of the transistor is grounded, and the input end of the transistor is connected to the first driving power supply through the coil of the control relay;

[0021] The positive pole of the coil of each relay is connected to the positive pole of the second driving power supply through the normally open contact of the control relay; the negative pole of the coil of each relay is connected to the negative pole of the second driving power supply.

[0022] In combination with the second aspect, in a possible implementation manner of the second aspect, the drive control circuit further includes: a first resistor and a second resistor;

[0023] The control end of the transistor is connected to the control chip through the first resistor;

[0024] The output end of the transistor is also connected to the control chip through the second resistor.

[0025] In combination with the second aspect, in a possible implementation manner of the second aspect, the drive control circuit further includes: a unidirectional diode;

[0026] The positive pole of the coil of the control relay is also connected to the output end of the unidirectional diode;

[0027] The cathode of the coil of the control relay is also connected to the input end of the unidirectional diode.

[0028] In combination with the second aspect, in a possible implementation manner of the second aspect, the voltage of the first driving power supply is 5V, and the voltage of the second driving power supply is 24V.

[0029] In combination with the second aspect, in a possible implementation manner of the second aspect, the resistance value of the first resistor is 1 kiloohm, and the resistance value of the second resistor is 2.2 kiloohms.

[0030] A third aspect of the embodiments of the present invention provides a feeder terminal, comprising: a magnetically controlled circuit breaker and a magnetically controlled circuit breaker control circuit as described in the second aspect or any one of the implementations of the second aspect.

[0031] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0032] The voltage conversion circuit provided by the embodiment of the present invention includes multiple capacitors, which are connected in sequence through relays; the first switch of each relay is connected to the positive electrode of the previous capacitor, and the second switch of each relay is connected to the negative electrode of the next capacitor; the normally closed contact of the first switch is connected to the positive electrode of the next capacitor, and the normally closed contact of the second switch is connected to the negative electrode of the previous capacitor; the normally open contacts of the first switch and the second switch are short-circuited; the coil of each relay is used to connect the drive control circuit; the positive electrode of the first capacitor is also used to connect the positive electrode of the charging power supply, and the negative electrode of the first capacitor is also used to connect the negative electrode of the charging power supply and the negative electrode of the magnetic control circuit breaker; the positive electrode of the last capacitor is also used to connect the positive electrode of the magnetic control circuit breaker. Thus, when the coils of each relay are not energized, the charging power supply charges the multiple capacitors in parallel; when the coils of each relay are energized, the normally closed contacts are disconnected, the normally open contacts are closed, and the capacitors are discharged in series to provide the voltage required for the magnetic control circuit breaker to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 is a schematic diagram of the structure of a voltage conversion circuit provided by an embodiment of the present invention;

[0035] Figure 2It is a structural schematic diagram of a magnetically controlled circuit breaker control circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0037] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0038] In the distribution network, the magnetic circuit breaker has protection, measurement and metering functions in one, and has built-in electronic voltage and current precision sensors, which can realize the intelligence and miniaturization of FTU. In terms of line protection, the magnetic circuit breaker can realize the function of fast opening (opening time ≤ 10ms), and has ultra-low power consumption, closing current < 20A, and opening current < 5A.

[0039] However, the external voltage of the secondary feeder terminal in the distribution network is generally 24V, and the operating voltage of the general magnetic control switch is about several hundred volts. When the secondary feeder terminal is used with the magnetic control switch, it is necessary to output a control voltage corresponding to several hundred volts, and at this time a voltage conversion circuit is required to boost the voltage.

[0040] Below Figure 1 Take as an example to illustrate the voltage conversion circuit provided by the embodiment of the present invention.

[0041] like Figure 1 As shown, the voltage conversion circuit includes: multiple capacitors (E1-E13), and the multiple capacitors are connected in sequence through relays (JDQ1-JDQ12).

[0042] The first switch 7 of each relay is connected to the positive pole of the previous capacitor, and the second switch 2 of each relay is connected to the negative pole of the next capacitor; the normally closed contact 6 of the first switch 7 is connected to the positive pole of the next capacitor, and the normally closed contact 3 of the second switch 2 is connected to the negative pole of the previous capacitor; the normally open contacts 8 and 1 of the first switch 7 and the second switch 2 are short-circuited; the coil of each relay is used to connect the drive control circuit (24V+ / 24V-); the positive pole of the first capacitor is also used to connect the positive pole (24VIN+) of the charging power supply, and the negative pole of the first capacitor is also used to connect the negative pole (24VIN-) of the charging power supply and the negative pole (350VOUT-) of the magnetically controlled circuit breaker; the positive pole of the last capacitor is also used to connect the positive pole (350VOUT+) of the magnetically controlled circuit breaker.

[0043] In the above voltage conversion circuit:

[0044] When the line is fault-free and the power supply is normal, the coils of JDQ1~JDQ12 shall not be energized, all the positive poles of capacitors E1~E13 are short-circuited through the first switches 7 and the normally closed contacts 6 of JDQ1~JDQ12, and all the negative poles of capacitors E1~E13 are short-circuited through the normally closed contacts 3 and the second switch 2 of JDQ1~JDQ12. The magnetically controlled circuit breaker does not operate, and the charging power supply at the secondary feeder terminal charges the capacitors E1~E13 in parallel through the two ends (24VIN+) and (24VIN- / 350VOUT-) of capacitor E1.

[0045] When a line fault occurs, the magnetically controlled circuit breaker needs to perform an opening action, or when the line fault is restored, the magnetically controlled circuit breaker needs to perform a closing action. At this time, the coils controlling JDQ1~JDQ12 are energized, the normally closed contacts 6 and 3 of JDQ1~JDQ12 are disconnected, and the normally open contacts 8 and 1 are closed. Contacts 8 and 1 are always in a short-circuited state. After JDQ1~JDQ12 are simultaneously actuated, the positive pole of E1 is connected to the negative pole of E2 through contact 7→contact 8→contact 1→contact 2 of JDQ1, and the positive pole of E2 is connected to the negative pole of E3 through contact 7→contact 8→contact 1→contact 2 of JDQ2. In this way, capacitors E1~E13 are connected in series in sequence. The positive pole of capacitor E13 is the output positive pole after series connection (contact 6 of JDQ13), and the negative pole of E1 is the output negative pole after series connection (contact 3 of JDQ1). The discharge after series connection can provide the voltage required for the magnetically controlled circuit breaker to operate.

[0046] exist Figure 1 In the embodiment shown, 12 relays with a driving voltage of DC24V single coil, two groups of normally open contacts and two groups of normally closed contacts can be used to realize DC voltage conversion, and the contact capacity meets the maximum current when the magnetic control switch is actuated. 11 2.7V / 1F capacitors can be connected in series to form a 29.7V / 0.09F capacitor module to realize DC voltage charging and discharging. Since the secondary feeder terminal is a DC24V power supply system, the voltage value is basically around 27V, so the capacitor module needs to leave a voltage margin to protect the capacitor from overcharging and damage. The input voltage at both ends of parallel charging (24VIN+) and (24VIN- / 350VOUT-) is 27V; the output voltage at both ends of series discharge (350VOUT+) and (24VIN- / 350VOUT-) is 27V*13=351V, so it can meet the voltage required for the magnetic control circuit breaker to actuate.

[0047] It should be pointed out that the number of the above-mentioned capacitors and relays, as well as the parameters of the capacitors can be selected according to requirements.

[0048] For example, the number of relays and capacitors can be increased or decreased according to the changes in input voltage and output voltage. The number of capacitors and relays can be determined as follows:

[0049]

[0050] Z = Y-1;

[0051] Among them, Y is the number of capacitors; S is the operating voltage required for the magnetically controlled circuit breaker to operate; X is the charging voltage of the charging power supply; and Z is the number of relays.

[0052] The parameters of the capacitor can meet the following conditions:

[0053] A*Y>S;

[0054] B*Y>H;

[0055] Among them, A is the rated voltage value of the capacitor; B is the capacitance value of the capacitor; H is the capacitance required for the magnetically controlled circuit breaker to operate.

[0056] It can be seen that the voltage conversion circuit provided by the embodiment of the present invention includes multiple capacitors, and the multiple capacitors are connected in sequence through relays; the first switch of each relay is connected to the positive pole of the previous capacitor, and the second switch of each relay is connected to the negative pole of the next capacitor; the normally closed contact of the first switch is connected to the positive pole of the next capacitor, and the normally closed contact of the second switch is connected to the negative pole of the previous capacitor; the normally open contacts of the first switch and the second switch are short-circuited; the coil of each relay is used to connect the drive control circuit; the positive pole of the first capacitor is also used to connect the positive pole of the charging power supply, and the negative pole of the first capacitor is also used to connect the negative pole of the charging power supply and the negative pole of the magnetically controlled circuit breaker; the positive pole of the last capacitor is also used to connect the positive pole of the magnetically controlled circuit breaker. Thus, when the coils of each relay are not energized, the charging power supply charges the multiple capacitors in parallel; when the coils of each relay are energized, the normally closed contacts are disconnected, the normally open contacts are closed, and the capacitors are discharged in series to provide the voltage required for the magnetically controlled circuit breaker to operate. This voltage conversion circuit can meet the collocation requirements of different action voltage levels between primary and secondary devices.

[0057] Based on the above voltage conversion circuit, the embodiment of the present invention also designs a magnetically controlled circuit breaker control circuit, including: a drive control circuit and the above voltage conversion circuit. The specific implementation of the voltage conversion circuit can be found in Figure 1 The description in the embodiment will not be repeated in this embodiment. In this embodiment, the driving control circuit is mainly described.

[0058] See also Figure 2 As shown, the drive control circuit includes: a control chip, a transistor Q1 and a control relay JDQ13.

[0059] The control terminal a of transistor Q1 is connected to the IO_KZ pin of the control chip, the output terminal b of transistor Q1 is grounded, and the input terminal c of transistor Q1 is connected to the first driving power supply 5VCC through the coil of control relay JDQ13. The positive pole 5 (24V+) of the coil of each relay JDQ1~JDQ12 in the voltage conversion circuit is connected to the positive pole (24VKZ+) of the second driving power supply through the normally open contact of the control relay JDQ13; the negative pole 4 of the coil of each relay JDQ1~JDQ12 is connected to the negative pole of the second driving power supply.

[0060] The second driving power source here may be the charging power source of the secondary feeder terminal mentioned above. The transistor Q1 may be an NPN transistor or a PNP transistor.

[0061] This embodiment uses program-driven IO, and uses transistor Q1 and control relay JDQ13 with a single coil and a single set of normally open contacts with a driving voltage of DC5V to form a driving control circuit to control the on and off of the coil driving voltage of 12 relays JDQ1~JDQ12. Only when the driving JDQ13 is turned on can JDQ1~JDQ12 in the voltage conversion circuit be turned on at the same time to achieve voltage conversion.

[0062] The control chip determines whether the opening and closing operation should be performed through the program to control the high and low level changes of the pin IO_KZ. For example, when the protection telemetry mutation amount is detected to be started and it is judged that the line has a protection fault (the mutation amount here refers to the mutation value of the corresponding current and voltage when the overcurrent / overvoltage fault occurs in the line), the control chip controls the IO_KZ pin to output a high level to turn on the transistor Q1, and 5VCC drives the JDQ13 coil to short the normally open contact, and connects the 24VKZ+ of the secondary feeder terminal to the coil pin 5 of JDQ1~JDQ12 in the voltage conversion circuit. Because the pin 4 of the coil is directly connected to the negative pole of the power supply, it can drive all relays JDQ1~JDQ12 to operate. Similarly, when the remote control closing start command / manual closing remote signal set 1 signal is detected, the IO_KZ pin also outputs a high level, and the circuit action process is consistent with the above, which will not be repeated here.

[0063] Optionally, the drive control circuit further includes: a first resistor R1 and a second resistor R2. The control end a of the transistor Q1 is connected to the IO_KZ pin of the control chip through the first resistor R1; the output end b of the transistor Q1 is also connected to the IO_KZ pin of the control chip through the second resistor R2.

[0064] The first resistor R1 and the second resistor R2 are added to prevent the IO_KZ pin from being directly shorted to GND and failing to control the transistor. The resistance value of the first resistor can be set to 1 kiloohm, and the resistance value of the second resistor can be set to 2.2 kiloohm.

[0065] Optionally, the drive control circuit further includes: a unidirectional diode D1.

[0066] The positive pole of the coil of the control relay JDQ13 is also connected to the output end of the unidirectional diode D1;

[0067] The cathode of the coil of the control relay JDQ13 is also connected to the input end of the unidirectional diode D1.

[0068] The function of the unidirectional diode D1 is to prevent the residual energy in the coil from being released to the outside and causing problems in the circuit when the feeder terminal is powered off. Therefore, D1 is connected to form a loop. After the power outage, the residual energy in the coil can be self-consumed through the loop formed by D1.

[0069] The embodiment of the present invention further provides a feeder terminal, comprising: a magnetically controlled circuit breaker and the magnetically controlled circuit breaker control circuit as described above. For the connection between the magnetically controlled circuit breaker and the magnetically controlled circuit breaker control circuit, and the specific implementation of the magnetically controlled circuit breaker control circuit, see Figure 1 and Figure 2 Description in the examples.

[0070] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A voltage conversion circuit, characterized in that: include: A plurality of capacitors, wherein the plurality of capacitors are connected in sequence via a relay; The first switch of each relay is connected to the positive electrode of the previous capacitor, and the second switch of each relay is connected to the negative electrode of the next capacitor; the normally closed contact of the first switch is connected to the positive electrode of the next capacitor, and the normally closed contact of the second switch is connected to the negative electrode of the previous capacitor; the normally open contacts of the first switch and the second switch are short-circuited; the coil of each relay is used to connect to the drive control circuit; The positive electrode of the first capacitor is also used to connect the positive electrode of the charging power source, and the negative electrode of the first capacitor is also used to connect the negative electrode of the charging power source and the negative electrode of the magnetically controlled circuit breaker; The positive terminal of the last capacitor is also used to connect the positive terminal of the magnetically controlled circuit breaker.

2. The voltage conversion circuit according to claim 1, characterized in that: The number of the capacitors and the relays is determined as follows: Z = Y-1; Wherein, Y is the number of the capacitors; S is the action voltage required for the magnetically controlled circuit breaker to operate; X is the charging voltage of the charging power supply; and Z is the number of the relays.

3. The voltage conversion circuit according to claim 1, wherein: The parameters of the capacitor meet the following conditions: A*Y>S; B*Y>H; Among them, A is the rated voltage value of the capacitor; B is the capacitance of the capacitor; S is the action voltage required for the magnetically controlled circuit breaker to operate; Y is the number of the capacitors; and H is the capacitance required for the magnetically controlled circuit breaker to operate.

4. The voltage conversion circuit according to claim 1, wherein: The voltage of the charging power supply is 24V; the number of the capacitors is 13; the number of the relays is 12; the rated voltage of the capacitor is 2.7V, and the capacitance is 1F.

5. A magnetically controlled circuit breaker control circuit, characterized in that: include: A drive control circuit and a voltage conversion circuit as claimed in any one of claims 1 to 4; The drive control circuit comprises: a control chip, a triode and a control relay; The control end of the transistor is connected to the control chip, the output end of the transistor is grounded, and the input end of the transistor is connected to the first driving power supply through the coil of the control relay; The positive pole of the coil of each relay is connected to the positive pole of the second driving power supply through the normally open contact of the control relay; the negative pole of the coil of each relay is connected to the negative pole of the second driving power supply.

6. The magnetically controlled circuit breaker control circuit according to claim 5, characterized in that: The drive control circuit further includes: a first resistor and a second resistor; The control end of the transistor is connected to the control chip through the first resistor; The output end of the transistor is also connected to the control chip through the second resistor.

7. The magnetically controlled circuit breaker control circuit according to claim 5, characterized in that: The drive control circuit further includes: a unidirectional diode; The positive pole of the coil of the control relay is also connected to the output end of the unidirectional diode; The cathode of the coil of the control relay is also connected to the input end of the unidirectional diode.

8. The magnetically controlled circuit breaker control circuit according to claim 5, characterized in that: The voltage of the first driving power supply is 5V, and the voltage of the second driving power supply is 24V.

9. The magnetically controlled circuit breaker control circuit according to claim 5, characterized in that: The resistance value of the first resistor is 1 kilo ohm, and the resistance value of the second resistor is 2.2 kilo ohms.

10. A feeder terminal, characterized in that: include: A magnetically controlled circuit breaker and a magnetically controlled circuit breaker control circuit as claimed in any one of claims 5 to 9.

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