CN215071627U - Intelligent molded case circuit breaker applied to carriage electric system - Google Patents
Intelligent molded case circuit breaker applied to carriage electric system Download PDFInfo
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- CN215071627U CN215071627U CN202022484025.7U CN202022484025U CN215071627U CN 215071627 U CN215071627 U CN 215071627U CN 202022484025 U CN202022484025 U CN 202022484025U CN 215071627 U CN215071627 U CN 215071627U
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Abstract
The embodiment of the utility model provides an intelligent moulded case circuit breaker for carriage electrical system, including the singlechip that stores control program and built-in time controller, current sampling module, circuit breaker closed position signal module, tripping device, current sampling module includes current transformer and the sampling resistance R, integral unit, filtering unit, the amplifier N that connect gradually, two output terminals of secondary side of current transformer connect the both ends of sampling resistance R respectively; the current sampling circuit comprises a first reference voltage source, a second reference voltage source, a first resistor R and a third resistor R, wherein the first reference voltage source and the second reference voltage source respectively output a first reference voltage and a second reference voltage; the amplifier N is a differential amplifier N, so that the interference of coupling noise in the output signal of the current transformer can be effectively inhibited, the current sampling precision is improved, and the detection accuracy is improved.
Description
Technical Field
The utility model relates to a circuit breaker technical field especially relates to be applied to carriage electrical system's intelligent moulded case circuit breaker.
Background
The circuit breaker is a switching device capable of closing, carrying, and opening/closing a current under a normal circuit condition and a current under an abnormal circuit condition within a prescribed time. The circuit breaker can be used for manually switching on and off the current, can automatically cut off the circuit when the circuit where the circuit breaker is located is abnormal, and has wide application.
On the train, just be provided with a large amount of circuit breakers and provide the guarantee for the safe operation of train, and adopt intelligent circuit breaker more at present stage. The current sampling end of the intelligent circuit breaker mostly adopts a current transformer with linear current induction performance, a central part of the intelligent circuit breaker is an electronic release which bears various protection, alarm, display and control functions of the intelligent circuit breaker, a signal of the electronic release is usually taken from a secondary output side of the current transformer sleeved on a bus, the induced secondary current output is in direct proportion to the differential of primary bus current, and then the secondary current output is further converted into a digital signal through conditioning and AD conversion of a rear-stage circuit, and is received by a subsequent single chip microcomputer to judge whether a loop needs to be disconnected or not.
However, in the current sampling process, when a small current appears on the primary side of the current transformer, the induced signal is weak, and is easily interfered by the coupling noise on the secondary output line of the current transformer, the interference generally belongs to common-mode interference, and due to the existence of the common-mode interference, the measurement accuracy of the electronic release is poor when the small current appears on the primary side, so that the electronic release is not suitable for being used on a train with high safety performance requirements, and the problem is solved.
SUMMERY OF THE UTILITY MODEL
An object of the embodiment of the utility model is to provide a be applied to carriage electrical system's intelligent moulded case circuit breaker to realize intelligent moulded case circuit breaker measurement accuracy's promotion. The specific technical scheme is as follows:
in a first aspect, an intelligent molded case circuit breaker applied to a carriage electric system comprises a single chip microcomputer, a current sampling module, a circuit breaker closing position signal module and a tripping mechanism, wherein a control program is stored in the single chip microcomputer, a time controller is arranged in the single chip microcomputer, and the current sampling module comprises a current sampling circuit coupled with the single chip microcomputer;
the output end of the circuit breaker closing position signal module is connected with the single chip microcomputer, and the input end of the tripping mechanism is connected with the single chip microcomputer;
the current sampling module comprises a current transformer, a sampling resistor R2, an integrating unit, a filtering unit and an amplifier N2 which are connected in sequence, and two output ends of the secondary side of the current transformer are respectively connected with two ends of the sampling resistor R2;
the current sampling circuit comprises a first reference voltage source, a second reference voltage source, a first resistor R1 and a third resistor R3, wherein the first reference voltage source and the second reference voltage source output a first reference voltage and a second reference voltage respectively; the first reference voltage and the second reference voltage have opposite polarities and equal amplitudes; the first resistor R1 and the third resistor R3 are respectively connected with two ends of the sampling resistor R2, so that a series circuit formed by connecting the first resistor R1, the sampling resistor R2 and the third resistor R3 in series is formed; the two ends of the series circuit are respectively connected with the output end of the first reference voltage source and the output end of the second reference voltage source; the amplifier N2 is a differential amplifier N2.
In a possible implementation manner, the resistances of the first resistor R1 and the third resistor R3 are substantially equal and far greater than the internal resistance of the secondary side of the current transformer, the resistance of the sampling resistor R2 is far greater than the resistances of the first resistor R1 and the third resistor R3, and the amplitudes of the first reference voltage and the second reference voltage are greater than or equal to the maximum value of the induced voltage of the secondary side of the current transformer under the condition of no disconnection.
In one possible implementation, one of the first reference voltage source and the second reference voltage source is a level shifter, and an input terminal of the level shifter is connected to an output terminal of the other reference voltage source.
In a possible implementation manner, the integrating unit includes a third resistor R3, a fifth resistor R5, and a first capacitor C1, one end of the third resistor R3 and one end of the fifth resistor R5 are respectively connected to two ends of the sampling resistor R2, and the other end of the third resistor R3 and the other end of the fifth resistor R5 are respectively connected to two ends of the first capacitor C1; the third resistor R3 and the fifth resistor R5 have the same resistance.
In a possible implementation manner, the filtering unit includes a sixth resistor R6, a seventh resistor R7, and second to fourth capacitors C4, one end of the sixth resistor R6 and one end of the seventh resistor R7 are respectively connected to two output ends of the integrating unit, the other end of the sixth resistor R6 and the other end of the seventh resistor R7 are respectively connected to two ends of the third capacitor C3, one end of the third capacitor C3 is connected in series with the second capacitor and then grounded, and the other end of the third capacitor C3 is connected in series with the fourth capacitor C4 and then grounded.
In a possible implementation manner, the single chip microcomputer is connected with a microswitch, the input end of the microswitch is connected with the single chip microcomputer, and the output end of the microswitch is connected with the input end of the tripping mechanism.
In a possible implementation manner, the single chip microcomputer is connected with a first shunt input module and a second shunt input module which are used for connecting external shunt signals.
The embodiment of the utility model provides an intelligence moulded case circuit breaker, sampling signal after filtering through the filtering unit can carry out the AD conversion, then obtain accurate current value through the singlechip operation, and when current transformer's the side that once is the undercurrent, the signal that current transformer secondary side coil induction came out is more faint, owing to adopt differential amplifier N2 that has higher common mode rejection ratio, can effectively restrain coupling noise's among the current transformer output signal interference, improve current sampling precision, improve the accuracy of detection.
Of course, it is not necessary for any product or method of the invention to achieve all of the above-described advantages at the same time.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other embodiments can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic block diagram of the present invention;
fig. 2 is a schematic circuit diagram according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a circuit principle when a secondary side of a current transformer of the embodiment of the present invention is broken.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The embodiment of the utility model provides an intelligent moulded case circuit breaker applied to carriage electrical system, as shown in figure 1, it includes singlechip 1, current sampling module 2, circuit breaker closed position signal module 4, tripping device 4 that store control program and built-in time controller, current sampling module 2 includes the current sampling circuit that is coupled with the singlechip;
the output end of the circuit breaker closing position signal module 4 is connected with the single chip microcomputer 1, and the input end of the tripping mechanism 4 is connected with the single chip microcomputer 1;
the current sampling module 2 can detect electric signals such as current, voltage, power and the like of the power supply and transmit the signals to the singlechip 1. The output end of the circuit breaker closed position signal module 4 is connected with the single chip microcomputer 1, the input end of the tripping mechanism 4 is connected with the single chip microcomputer 1, and the circuit breaker closed position signal module 4 can detect the opening and closing state of the circuit breaker and transmit the opening and closing state to the single chip microcomputer 1.
The embodiment can control the shedding mechanism through the electronic element, has high control precision, can detect the power utilization condition of the circuit, can realize three-section protection of overload long delay, overload short delay and short circuit instant, and can play a better protection role on the circuit.
For example, the single chip microcomputer 1 can adopt an LPC1114ARM processor, the running speed is high, and the real-time performance of the processed signal can be ensured.
As shown in fig. 1 and fig. 2, the current sampling module includes a current transformer 22, and a sampling resistor R2, an integrating unit, a filtering unit, and an amplifier N2, which are connected in sequence, where two output terminals on a secondary side of the current transformer 22 are respectively connected to two ends of the sampling resistor R2;
the current sampling circuit further comprises a first reference voltage source, a second reference voltage source, a first resistor R1 and a third resistor R3, wherein the first reference voltage source and the second reference voltage source respectively output a first reference voltage Vref1 and a second reference voltage Vref 1; the first reference voltage and the second reference voltage have opposite polarities and equal amplitudes; the first resistor R1 and the third resistor R3 are respectively connected with two ends of the sampling resistor R2, so that a series circuit formed by connecting the first resistor R1, the sampling resistor R2 and the third resistor R3 in series is formed; the two ends of the series circuit are respectively connected with the output end of the first reference voltage source and the output end of the second reference voltage source; amplifier N2 is a differential amplifier N2.
In this embodiment, as shown in fig. 1, the current transformer 22 adopts an air-core current transformer 22, the reference voltage Vref1 and the reference voltage Vref2 are both directly supplied by a reference voltage source, a secondary coil L1 of the air-core current transformer 22 is respectively connected with two ends a and b of a sampling resistor R2, the reference voltage Vref1 is connected with the end a of a resistor R2 through a resistor R1, and the reference voltage Vref2 is connected with the other end b of the resistor R2 through a resistor R3; the two ends of the resistor R2 are sequentially connected with the integrating unit, the filtering unit and the amplifier N2.
The reference voltage Vref1 has a polarity opposite to that of the reference voltage Vref2 and a magnitude equal to that of the reference voltage Vref 2. The reference voltage Vref2 in the present embodiment is obtained by inputting the reference voltage Vref1 to the level shifter N1, but of course, the reference voltage Vref1 may be obtained by inputting the reference voltage Vref2 to the level shifter.
The amplifier N2 may be any of the existing amplifiers, preferably a differential amplifier, which has a high common mode rejection ratio, and can better reject the interference of the coupling noise, thereby further improving the sampling accuracy.
The integrating unit comprises a third resistor R3, a fifth resistor R5 and a first capacitor C1, one end of the third resistor R3 and one end of the fifth resistor R5 are respectively connected with two ends of the sampling resistor R2, and the other end of the third resistor R3 and the other end of the fifth resistor R5 are respectively connected with two ends of the first capacitor C1; the third resistor R3 and the fifth resistor R5 have the same resistance.
In this embodiment, R4 is equal to R5, the filtering unit includes a sixth resistor R6, a seventh resistor R7, and second to fourth capacitors C4, one end of the sixth resistor R6 and one end of the seventh resistor R7 are respectively connected to two output ends of the integrating unit, the other end of the sixth resistor R6 and the other end of the seventh resistor R7 are respectively connected to two ends of a third capacitor C3, one end of the third capacitor C3 is connected in series with the second capacitor and then grounded, and the other end of the third capacitor C3 is connected in series with the fourth capacitor C4 and then grounded. The sampling signal filtered by the filtering unit can be subjected to A/D conversion, and then an accurate current value is obtained through operation.
When the primary side of the hollow current transformer 22 is low current, the signal induced by the coil L1 on the secondary side of the hollow current transformer 22 is weak, and the interference of coupling noise in the output signal of the current transformer 22 can be effectively suppressed due to the adoption of an instrumentation amplifier or a differential amplifier with a high common mode rejection ratio, so that the current sampling precision is improved.
The resistance values of the first resistor R1 and the third resistor R3 are substantially equal and far greater than the internal resistance of the secondary side of the current transformer 22, the resistance value of the sampling resistor R2 is far greater than the resistance values of the first resistor R1 and the third resistor R3, and the amplitudes of the first reference voltage and the second reference voltage are greater than or equal to the maximum value of the induced voltage of the secondary side of the current transformer 22 under the condition of no disconnection. The current sampling circuit can further realize the detection of the disconnection or disconnection fault of the secondary side coil L1 through the design of circuit parameters.
When the secondary coil L1 of the air-core current transformer 22 is disconnected or disconnected, the equivalent circuit is as shown in fig. 3, the voltage difference UR2 across the sampling resistor R2 is a signal induced by the secondary coil L1 of the air-core current transformer 22 when the secondary coil L1 of the air-core current transformer 22 is normally connected, and the voltage difference UR2 across the sampling resistor R2 is. The internal resistance of the secondary side coil of the air-core current transformer 22 is generally 10-100 Ω, in this embodiment, the resistance R1 is R3, which is about 10k Ω, the resistance R2 is 100-200 k Ω, and the Vref1 has an amplitude of 1/2 of the power voltage of the amplifier N2, so when the secondary side coil L1 of the air-core current transformer 22 is disconnected or disconnected, the voltage difference UR2 across the sampling resistance R2 is about (Vref1-Vref2), when the secondary side coil L1 of the air-core current transformer 22 is normally connected, the voltage difference UR2 across the sampling resistance R2 is about USENSE, the maximum value of the USENSE is defined to be much smaller than (1-Vref 2), for example, (Vref1-Vref2) is at least twice the maximum value of the USENSE, the AD converter of the microprocessor N3 is obviously different between the measurement voltage read when the secondary side coil L1 is normally connected and the measurement voltage read when the secondary side coil L1 of the air-core current transformer 22 is disconnected or disconnected, that is, the microprocessor can easily identify whether the secondary side coil L1 of the air-core current transformer 22 is broken or disconnected.
One of the first reference voltage source and the second reference voltage source is a level shifter, and the input end of the level shifter is connected with the output end of the other reference voltage source. The single chip microcomputer is connected with a microswitch, the input end of the microswitch is connected with the single chip microcomputer, and the output end of the microswitch is connected with the input end of the tripping mechanism. The shunt release is a short-time working system, the coil power-on time generally cannot exceed 1S, otherwise, the wire is burnt, therefore, the input end of the release mechanism 4 is connected with the microswitch 5, the input end of the microswitch 5 is connected with the singlechip 1, after the circuit breaker is released and disconnected or when the singlechip 1 outputs an undervoltage signal and an overvoltage signal, the microswitch 5 is switched from a normally closed state to a normally open state, even if a button is manually pressed at the moment, the shunt coil cannot be powered on again, the coil burning situation is avoided, and when the circuit breaker is in a buckling brake or reset state, the microswitch is in the normally closed position again.
As a preferred embodiment of the present invention, the tripping mechanism 4 is an electromagnetic tripping mechanism.
The single chip microcomputer is connected with a first shunt input module and a second shunt input module which are used for being connected with external shunt signals. Therefore, shunt tripping can be realized through an external interrupt signal.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (7)
1. An intelligent molded case circuit breaker applied to a carriage electric system comprises a single chip microcomputer (1) which stores a control program and is internally provided with a time controller, a current sampling module (2), a circuit breaker closing position signal module (3) and a tripping mechanism (4), and is characterized in that the current sampling module (2) comprises a current sampling circuit (21) coupled with the single chip microcomputer (1);
the output end of the circuit breaker closing position signal module (3) is connected with the single chip microcomputer (1), and the input end of the tripping mechanism (4) is connected with the single chip microcomputer (1);
the current sampling module (2) comprises a current transformer 22, and a sampling resistor R2, an integrating unit, a filtering unit and an amplifier N2 which are connected in sequence, wherein two output ends on the secondary side of the current transformer 22 are respectively connected with two ends of the sampling resistor R2;
the current sampling circuit (21) comprises a first reference voltage source, a second reference voltage source, a first resistor R1 and a third resistor R3, wherein the first reference voltage source and the second reference voltage source output a first reference voltage and a second reference voltage respectively; the first reference voltage and the second reference voltage have opposite polarities and equal amplitudes; the first resistor R1 and the third resistor R3 are respectively connected with two ends of the sampling resistor R2, so that a series circuit formed by connecting the first resistor R1, the sampling resistor R2 and the third resistor R3 in series is formed; the two ends of the series circuit are respectively connected with the output end of the first reference voltage source and the output end of the second reference voltage source; the amplifier N2 is a differential amplifier N2.
2. The intelligent molded case circuit breaker as recited in claim 1, wherein the first resistor R1 and the third resistor R3 have substantially equal resistance values and are substantially larger than the internal resistance of the secondary side of the current transformer 22, the sampling resistor R2 has substantially larger resistance values than the first resistor R1 and the third resistor R3, and the magnitudes of the first reference voltage and the second reference voltage are substantially equal to or larger than the maximum value of the induced voltage of the secondary side of the current transformer 22 in the case of no disconnection.
3. The intelligent molded case circuit breaker of claim 2, wherein one of the first reference voltage source and the second reference voltage source is a level shifter having an input terminal connected to an output terminal of the other reference voltage source.
4. The intelligent molded case circuit breaker of claim 3, wherein the integration unit comprises a fourth resistor R4, a fifth resistor R5 and a first capacitor C1, one end of the third resistor R3 and one end of the fifth resistor R5 are respectively connected to two ends of the sampling resistor R2, and the other end of the third resistor R3 and the other end of the fifth resistor R5 are respectively connected to two ends of the first capacitor C1; the third resistor R3 and the fifth resistor R5 have the same resistance.
5. The intelligent molded case circuit breaker of claim 4, wherein the filtering unit comprises a sixth resistor R6, a seventh resistor R7, and second to fourth capacitors C4, one end of the sixth resistor R6 and one end of the seventh resistor R7 are respectively connected to two output terminals of the integrating unit, the other end of the sixth resistor R6 and the other end of the seventh resistor R7 are respectively connected to two ends of a third capacitor C3, one end of the third capacitor C3 is connected in series with the second capacitor and then grounded, and the other end of the third capacitor C3 is connected in series with the fourth capacitor C4 and then grounded.
6. The intelligent molded case circuit breaker according to claim 1, wherein: the single chip microcomputer (1) is connected with a microswitch (5), the input end of the microswitch (5) is connected with the single chip microcomputer (1), and the output end of the microswitch (5) is connected with the input end of the tripping mechanism (4).
7. The intelligent molded case circuit breaker according to claim 1, wherein: the single chip microcomputer (1) is connected with a first shunt input module (71) and a second shunt input module (72) which are used for connecting external shunt signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022484025.7U CN215071627U (en) | 2020-10-31 | 2020-10-31 | Intelligent molded case circuit breaker applied to carriage electric system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022484025.7U CN215071627U (en) | 2020-10-31 | 2020-10-31 | Intelligent molded case circuit breaker applied to carriage electric system |
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| Publication Number | Publication Date |
|---|---|
| CN215071627U true CN215071627U (en) | 2021-12-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022484025.7U Active CN215071627U (en) | 2020-10-31 | 2020-10-31 | Intelligent molded case circuit breaker applied to carriage electric system |
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| Country | Link |
|---|---|
| CN (1) | CN215071627U (en) |
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- 2020-10-31 CN CN202022484025.7U patent/CN215071627U/en active Active
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