A power hybrid detection circuit and device for railway signal power supply panel

Abstract

This invention provides a power mixing detection circuit and device for railway signal power supply panels, including a first input interface, a second input interface, a sampling circuit, a voltage follower, a differential proportional operation circuit, and an addition / subtraction operation circuit. The first and second input interfaces are connected to the voltage follower through the sampling circuit. The output of the voltage follower is connected to the input of the differential proportional operation circuit and the input of the addition / subtraction operation circuit, respectively. The output of the differential proportional operation circuit serves as the first output of the power mixing detection circuit, and the output of the addition / subtraction operation circuit serves as the second output of the power mixing detection circuit. The solution of this invention acquires analog voltage signals with high accuracy and the acquisition circuit has low cost.

Description

Technical Field

[0001] This utility model relates to the field of power supply mixing detection technology for power supply panels, specifically, to a power supply mixing detection circuit and device for railway signal power supply panels. Background Technology

[0002] With the rapid development of the railway industry, railway power supply systems have become increasingly complex, evolving from simple early power supply modes to the coexistence of multiple power supply methods, such as AC power, DC power, and power supply systems of different voltage levels. The increased interconnection between different power systems has amplified the risk of power line mixing. Mixed power lines can easily affect equipment operation or cause irreparable damage. It should be noted that, for example, power line mixing can occur when the insulation of two power lines is damaged and the damaged portions come into contact.

[0003] In actual field situations, when detecting power supply mixing, the voltage of the power supply is usually measured manually using a megohmmeter at regular intervals. The degree of mixing needs to be judged based on the different voltage levels of each power supply and experience. This operation is risky, time-consuming, labor-intensive, and cannot guarantee the reliability of the data.

[0004] In the prior art, such as the patent document with authorization announcement number CN 209215561 U, entitled "Power Supply Mixed Detection Device," which includes an analog signal acquisition circuit connected to an ARM motherboard, the drawback of this analog signal acquisition circuit is that it uses a single-ended analog input acquisition method, which is easily affected by external noise, thus affecting signal accuracy. Moreover, this analog signal acquisition circuit has a large number of operational amplifier circuits, resulting in higher costs.

[0005] In order to solve the above problems, people have been seeking an ideal technological solution. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a power supply mixing detection circuit and device for railway signal power supply panels, thereby reducing costs and improving the accuracy of mixing detection.

[0007] To achieve the above objectives, the first aspect of this utility model provides a power supply mixing detection circuit for a railway signal power supply panel, comprising a first input interface, a second input interface, a sampling circuit, a voltage follower, a differential proportional operation circuit, and an addition and subtraction operation circuit;

[0008] The first and second input interfaces are connected to a voltage follower via a sampling circuit.

[0009] The output of the voltage follower is connected to the input of the differential proportional operation circuit and the input of the addition and subtraction operation circuit, respectively.

[0010] The output terminal of the differential proportional operation circuit serves as the first output terminal of the power supply mixing detection circuit.

[0011] The output terminal of the addition and subtraction operation circuit serves as the second output terminal of the power supply mixing detection circuit.

[0012] Based on the above, the differential proportional operational circuit includes resistors R2, R4, R7, R8, and a second operational amplifier.

[0013] The inverting input of the second operational amplifier is connected to the output of the voltage follower via resistor R4;

[0014] Resistor R2 is connected in parallel between the inverting input terminal and the output terminal of the second operational amplifier; the output terminal of the second operational amplifier serves as the output terminal of the differential proportional operational circuit.

[0015] The non-inverting input of the second operational amplifier is connected to the first power supply through resistor R7;

[0016] The non-inverting input of the second operational amplifier is grounded through resistor R8.

[0017] Based on the above, the addition and subtraction operation circuit includes resistors R10, R11, R12, R13, R14, R15 and a third operational amplifier;

[0018] The inverting input terminal of the addition / subtraction circuit is grounded through resistor R12;

[0019] Resistor R10 and resistor R12 are connected in parallel;

[0020] Resistor R11 is connected in parallel between the inverting input terminal of the addition / subtraction operation circuit and the output terminal of the third operational amplifier; the output terminal of the third operational amplifier serves as the output terminal of the addition / subtraction operation circuit.

[0021] The non-inverting input of the addition / subtraction circuit is connected to the output of the voltage follower through resistor R13;

[0022] The non-inverting input terminal of the addition and subtraction circuit is connected to the second power supply through resistor R14;

[0023] The non-inverting input terminal of the addition and subtraction circuit is grounded through resistor R15.

[0024] Based on the above, the sampling circuit includes a reference power supply circuit, resistor R3, resistor R5 and resistor R9;

[0025] The voltage follower includes resistor R1, resistor R6, and a first operational amplifier;

[0026] The non-inverting input of the first operational amplifier is connected to the first input interface through resistor R3; the inverting input of the first operational amplifier is connected to the second input interface in sequence through resistor R6, reference power supply circuit, and resistor R9; resistor R1 is connected in parallel between the inverting input of the first operational amplifier and the output of the first operational amplifier; resistor R5 is connected in parallel between the non-inverting input of the first operational amplifier and the first connection point, which is the connection point between the reference power supply circuit and resistor R6, and the first connection point is grounded;

[0027] The output of the first operational amplifier serves as the output of the voltage follower.

[0028] Based on the above, it also includes isolation amplifiers;

[0029] An isolation amplifier is connected in series between the output of the voltage follower and the second connection point, which is the connection point between the input of the differential proportional operation circuit and the input of the addition and subtraction operation circuit.

[0030] Based on the above, capacitor C1 is also included;

[0031] Capacitor C1 is connected in parallel with resistor R5.

[0032] Based on the above, a power supply mixing detection circuit for a railway signal power supply panel, including any of the above embodiments, is provided.

[0033] It also includes a power supply module, an analog-to-digital converter module, a DSP digital signal processing module, a CAN communication module, and a host computer;

[0034] The first and second output terminals are connected to an analog-to-digital converter module;

[0035] The analog-to-digital conversion module is connected in sequence to the DSP digital signal processing module, the CAN communication module, and then to the host computer.

[0036] The power supply module is used to supply power to the analog-to-digital conversion module, the DSP digital signal processing module, the CAN communication module, and the power supply mixing detection circuit.

[0037] Based on the above, a resistor R24 ​​and a common-mode suppressor L1 are connected in parallel between CANH and CANL of the CAN communication module.

[0038] Based on the above, the CAN communication module adopts the CAN isolation transceiver ADM3053;

[0039] The analog-to-digital converter module uses an ADS1271 analog-to-digital converter chip.

[0040] This invention has substantial features and advancements compared to existing technologies. Specifically, compared to acquisition circuits that only input one analog voltage signal to the analog-to-digital converter circuit, the acquisition circuit of this invention has two analog voltage signals input to the analog-to-digital converter circuit. One analog voltage signal acquisition circuit includes a differential proportional operation circuit, and the other analog voltage signal acquisition circuit includes an addition and subtraction operation circuit. During the acquisition process, only one analog voltage signal may be affected by external noise interference. Therefore, the acquisition circuit of this invention can improve the accuracy of the acquired analog voltage signal.

[0041] Furthermore, the analog signal acquisition circuit in the patent document with authorization announcement number CN 209215561 U has a large number of operational amplifier circuits, which leads to higher costs, while the circuit of this invention has fewer operational amplifier circuits, thus reducing costs. Attached Figure Description

[0042] Figure 1 This is a structural block diagram of a power mixing detection circuit for a railway signal power supply panel according to the present invention;

[0043] Figure 2 This is a schematic diagram of the differential proportional operation circuit and the addition / subtraction operation circuit of this utility model.

[0044] Figure 3 This is a schematic diagram of the power mixing detection circuit for a railway signal power supply panel according to the present invention.

[0045] Figure 4 This is a schematic diagram of the circuit principle of the analog-to-digital conversion module of this utility model;

[0046] Figure 5 This is a schematic diagram of the circuit principle of the CAN communication module of this utility model. Detailed Implementation

[0047] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0048] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application.

[0049] For a data acquisition circuit that only inputs one analog voltage signal to the analog-to-digital converter, the accuracy of the acquired voltage signal is low when the voltage signal is interfered with by external noise during the acquisition process. This invention improves the accuracy of the acquired analog voltage signal by using two analog signal acquisition circuits to input the signals separately to the analog-to-digital converter.

[0050] Example 1

[0051] like Figure 1 As shown in the figure, this embodiment provides a specific implementation of a power supply mixing detection circuit for a railway signal power supply panel.

[0052] A power mixing detection circuit for a railway signal power supply panel includes a first input interface, a second input interface, a sampling circuit, a voltage follower, a differential proportional operation circuit, and an addition and subtraction operation circuit.

[0053] The first and second input interfaces are connected to a voltage follower via a sampling circuit.

[0054] The output of the voltage follower is connected to the input of the differential proportional operation circuit and the input of the addition and subtraction operation circuit, respectively.

[0055] The output terminal of the differential proportional operation circuit serves as the first output terminal of the power supply mixing detection circuit.

[0056] The output terminal of the addition and subtraction operation circuit serves as the second output terminal of the power supply mixing detection circuit.

[0057] The first input interface connects to one of the two power supplies to be tested for hybrid power supply mixing, and the second input interface connects to the other power supply. Signals from both input interfaces are converted from high-voltage to low-voltage signals by a sampling circuit to obtain a suitable sampling voltage for subsequent analysis and processing. A voltage follower isolates the input and output circuits, improving circuit stability and reliability. A differential proportional operation circuit and an addition / subtraction operation circuit adjust the voltage signal to a range suitable for analog-to-digital conversion. The adjusted voltage signal is used to determine whether the power supplies are hybrid or the degree of hybridization.

[0058] It should be noted that when power supply mixing occurs, the current between the first and second input interfaces changes compared to when mixing does not occur. Consequently, the sampling voltage collected by the sampling circuit changes, and this is used to determine whether the power supply is mixed or the degree of mixing. Specifically, when the two power supplies to be detected are not mixed, the voltage and current between the first and second input interfaces are higher, resulting in a higher sampling voltage collected by the sampling circuit. Conversely, when the two power supplies are mixed, the voltage and current between the first and second input interfaces are lower, resulting in a lower sampling voltage collected by the sampling circuit. The differential proportional operation circuit and the addition / subtraction operation circuit perform calculations on the sampled voltage, outputting different voltage signals under mixed and non-mixed conditions. The voltages output by the differential proportional operation circuit and the addition / subtraction operation circuit are input to the digital signal processing module through the analog-to-digital conversion module for processing to determine whether the power supply is mixed or the degree of mixing.

[0059] Example 2

[0060] like Figure 2 As shown, the difference between this embodiment and Embodiment 1 is that a specific implementation method for a differential proportional operation circuit and an addition / subtraction operation circuit is provided.

[0061] The differential proportional operational circuit includes resistors R2, R4, R7, R8, and a second operational amplifier (U2A).

[0062] The inverting input of the second operational amplifier is connected to the output of the voltage follower via resistor R4;

[0063] Resistor R2 is connected in parallel between the inverting input terminal and the output terminal of the second operational amplifier; the output terminal of the second operational amplifier serves as the output terminal of the differential proportional operational circuit.

[0064] The non-inverting input of the second operational amplifier is connected to the first power supply through resistor R7;

[0065] The non-inverting input of the second operational amplifier is grounded through resistor R8.

[0066] It should be noted that the voltage of the first power supply is 2.5V. The voltage signal output by the voltage follower is calculated by the differential proportional operational circuit. The voltage at the output of the differential proportional operational circuit is -0.12*U7+2.5V, where * represents the multiplication sign, U7 is the output voltage of the voltage follower, and 2.5V is the voltage of the first power supply.

[0067] The addition and subtraction circuit includes resistors R10, R11, R12, R13, R14, R15 and a third operational amplifier (U2B).

[0068] The inverting input terminal of the addition / subtraction circuit is grounded through resistor R12;

[0069] Resistor R10 and resistor R12 are connected in parallel;

[0070] Resistor R11 is connected in parallel between the inverting input terminal of the addition / subtraction operation circuit and the output terminal of the third operational amplifier; the output terminal of the third operational amplifier serves as the output terminal of the addition / subtraction operation circuit.

[0071] The non-inverting input of the addition / subtraction circuit is connected to the output of the voltage follower through resistor R13;

[0072] The non-inverting input terminal of the addition and subtraction circuit is connected to the second power supply through resistor R14;

[0073] The non-inverting input terminal of the addition and subtraction circuit is grounded through resistor R15.

[0074] It should be noted that the voltage of the second power supply is 2.5V. The voltage signal output by the voltage follower is calculated by the addition and subtraction operation circuit, and the voltage at the output of the addition and subtraction operation circuit is 0.12*U7+2.5V, where 2.5V is the voltage of the second power supply.

[0075] Example 3

[0076] like Figure 3 As shown, the difference between this embodiment and Embodiment 1 or 2 is that it provides a specific implementation method for the sampling circuit and voltage follower.

[0077] The sampling circuit includes a reference power supply circuit, resistor R3, resistor R5, and resistor R9;

[0078] The voltage follower includes resistors R1 and R6 and a first operational amplifier (U1B).

[0079] The non-inverting input of the first operational amplifier is connected to the first input interface (IN1) via resistor R3; the inverting input of the first operational amplifier is connected in sequence to resistor R6, the reference power supply circuit, and resistor R9 before being connected to the second input interface (IN2); resistor R1 is connected in parallel between the inverting input of the first operational amplifier and the output of the first operational amplifier; resistor R5 is connected in parallel between the non-inverting input of the first operational amplifier and the first connection point, which is the connection point between the reference power supply circuit and resistor R6, and the first connection point is grounded;

[0080] The output of the first operational amplifier serves as the output of the voltage follower.

[0081] It also includes capacitor C1; capacitor C1 is connected in parallel with resistor R5.

[0082] The reference power supply circuit uses a 36-volt DC power supply, which serves as a reference voltage. This DC power supply voltage can be provided by a parallel voltage regulator, generated directly using an onboard power chip, or provided by an external reference power supply.

[0083] The function of resistors R3 and R9 is to reduce the voltage, and the function of resistor R5 is to sample the voltage.

[0084] Capacitor C1 is used to buffer the sampling voltage; the voltage follower works together with capacitor C1 to filter out input noise.

[0085] It should be noted that when the two power supplies to be tested are not mixing, the current between the first and second input interfaces is relatively large. This current flows through resistors R3, R9, and R5, generating a large voltage across resistor R5. This voltage across resistor R5 is filtered by capacitor C1 and a voltage follower, resulting in a relatively stable output voltage from the voltage follower. The voltage output from the voltage follower is then input to the differential proportional operation circuit and the addition / subtraction operation circuit for calculation.

[0086] When the two power supplies to be tested mix, the current between the first and second input interfaces is small. This current flows through resistors R3, R9, and R5, generating a small voltage across resistor R5. This voltage is filtered by capacitor C1 and a voltage follower, resulting in a relatively stable output voltage from the voltage follower. The voltage output from the voltage follower is then input to a differential proportional operation circuit and an addition / subtraction operation circuit for calculation.

[0087] Example 4

[0088] The difference between this embodiment and Embodiment 1 or 2 is that an isolation amplifier is added to the power supply mixing detection circuit.

[0089] An isolation amplifier is connected in series between the output of the voltage follower and the second connection point, which is the connection point between the input of the differential proportional operational circuit and the input of the addition / subtraction operational circuit. For example, an isolation amplifier that can guarantee a 3000V isolation withstand voltage can be selected.

[0090] Example 5

[0091] The difference between this embodiment and any of the above embodiments is that it provides a specific implementation method for a power supply mixing detection device for a railway signal power supply panel.

[0092] The power supply mixing detection device includes a power supply mixing detection circuit for a railway signal power supply panel according to any of the above embodiments;

[0093] It also includes a power supply module and an analog-to-digital converter module (such as...) Figure 4 (as shown), DSP digital signal processing module, CAN communication module (as shown) Figure 5 (as shown) and the host computer;

[0094] The power supply module is used to supply power to the analog-to-digital converter module, the DSP digital signal processing module, the CAN communication module, and the power supply mixing detection circuit;

[0095] The first and second output terminals are connected to an analog-to-digital converter module;

[0096] The analog-to-digital conversion module is sequentially connected to the DSP digital signal processing module, the CAN communication module, and the host computer. The DSP digital signal processing module is used to obtain the degree of power supply mixing or to determine whether power supplies are mixed. Specifically, for example, the DSP digital signal processing module can convert the output voltage of the power supply mixing detection circuit (the output voltage of the differential proportional operation circuit and the addition and subtraction operation circuit) into the corresponding line-to-line impedance value between the two power supplies, and then obtain the degree of power supply mixing or determine whether power supplies are mixed based on the line-to-line impedance value.

[0097] It should be noted that: the power supply mixing detection circuit is used to adjust the amplitude of the analog signal to a suitable range for analog-to-digital conversion and to remove noise and interference from the analog signal. The analog-to-digital conversion module is used to convert the analog signal into a digital signal for subsequent digital signal processing. The DSP digital signal processing module is used to analyze and process the digital signal to obtain the mixing status between the two power supplies. The CAN communication module is used to enable communication between the DSP digital signal processing module and the host computer.

[0098] The current between the first and second input interfaces is filtered and processed by a power supply mixing detection circuit to obtain an output voltage suitable for analog-to-digital conversion. This output voltage is then converted into a digital signal by the analog-to-digital conversion module. This digital signal is analyzed and processed by a DSP digital signal processing module to obtain the mixing information between the two power supplies. This mixing information is then transmitted to the host computer via a CAN communication module.

[0099] A resistor R24 ​​and a common-mode suppressor L1 are connected in parallel between CANH and CANL of the CAN communication module.

[0100] The CAN communication module uses a CAN isolation transceiver ADM3053; the analog-to-digital converter module uses an ADS1271 analog-to-digital converter chip.

[0101] In some embodiments, the second and third operational amplifiers may be rail-to-rail operational amplifiers.

[0102] In some embodiments: the resistance of resistors R3 and R9 is 240K ohms; the resistance of resistor R5 is 10K ohms; the resistance of resistors R1 and R6 is the same; the resistance of resistors R2, R7, R10, R11, R14 and R15 is 12K ohms; and the resistance of resistors R4, R8, R12 and R13 is 100K ohms.

[0103] In some embodiments, to improve anti-interference measures, isolation protection measures are adopted for the acquisition port, power interface and communication interface. Isolation protection can be achieved through isolation chips, opto-isolators or surge protectors.

[0104] In some embodiments, this invention can be used for detecting the mixed state of AC and DC power supplies within 250V.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A power supply mixing detection circuit for a railway signal power supply panel, characterized in that: It includes a first input interface, a second input interface, a sampling circuit, a voltage follower, a differential proportional operation circuit, and an addition and subtraction operation circuit; The first and second input interfaces are connected to a voltage follower via a sampling circuit. The output of the voltage follower is connected to the input of the differential proportional operation circuit and the input of the addition and subtraction operation circuit, respectively. The output terminal of the differential proportional operation circuit serves as the first output terminal of the power supply mixing detection circuit. The output terminal of the addition and subtraction operation circuit serves as the second output terminal of the power supply mixing detection circuit.

2. The power supply mixing detection circuit for a railway signal power supply panel according to claim 1, characterized in that: The differential proportional operational circuit includes resistors R2, R4, R7, and R8, and a second operational amplifier. The inverting input of the second operational amplifier is connected to the output of the voltage follower via resistor R4; Resistor R2 is connected in parallel between the inverting input terminal and the output terminal of the second operational amplifier; the output terminal of the second operational amplifier serves as the output terminal of the differential proportional operational circuit. The non-inverting input of the second operational amplifier is connected to the first power supply through resistor R7; The non-inverting input of the second operational amplifier is grounded through resistor R8.

3. The power supply mixing detection circuit for a railway signal power supply panel according to claim 1, characterized in that: The addition and subtraction circuit includes resistors R10, R11, R12, R13, R14, R15 and a third operational amplifier; The inverting input terminal of the addition / subtraction circuit is grounded through resistor R12; Resistor R10 and resistor R12 are connected in parallel; Resistor R11 is connected in parallel between the inverting input terminal of the addition / subtraction operation circuit and the output terminal of the third operational amplifier; the output terminal of the third operational amplifier serves as the output terminal of the addition / subtraction operation circuit. The non-inverting input of the addition / subtraction circuit is connected to the output of the voltage follower through resistor R13; The non-inverting input terminal of the addition and subtraction circuit is connected to the second power supply through resistor R14; The non-inverting input terminal of the addition and subtraction circuit is grounded through resistor R15.

4. A power supply mixing detection circuit for a railway signal power supply panel according to claim 1, 2, or 3, characterized in that: The sampling circuit includes a reference power supply circuit, resistor R3, resistor R5, and resistor R9; The voltage follower includes resistor R1, resistor R6, and a first operational amplifier; The non-inverting input of the first operational amplifier is connected to the first input interface through resistor R3; the inverting input of the first operational amplifier is connected to the second input interface in sequence through resistor R6, reference power supply circuit, and resistor R9; resistor R1 is connected in parallel between the inverting input of the first operational amplifier and the output of the first operational amplifier; resistor R5 is connected in parallel between the non-inverting input of the first operational amplifier and the first connection point, which is the connection point between the reference power supply circuit and resistor R6, and the first connection point is grounded; The output of the first operational amplifier serves as the output of the voltage follower.

5. A power supply mixing detection circuit for a railway signal power supply panel according to claim 1, 2, or 3, characterized in that: It also includes isolation amplifiers; An isolation amplifier is connected in series between the output of the voltage follower and the second connection point, which is the connection point between the input of the differential proportional operation circuit and the input of the addition and subtraction operation circuit.

6. A power supply mixing detection circuit for a railway signal power supply panel according to claim 4, characterized in that: It also includes capacitor C1; Capacitor C1 is connected in parallel with resistor R5.

7. A power supply mixing detection device for railway signal power supply panels, characterized in that: Includes a power supply mixing detection circuit for a railway signal power supply panel according to any one of claims 1 to 6; It also includes a power supply module, an analog-to-digital converter module, a DSP digital signal processing module, a CAN communication module, and a host computer; The first and second output terminals are connected to an analog-to-digital converter module; The analog-to-digital conversion module is connected in sequence to the DSP digital signal processing module, the CAN communication module, and then to the host computer. The power supply module is used to supply power to the analog-to-digital conversion module, the DSP digital signal processing module, the CAN communication module, and the power supply mixing detection circuit.

8. A power supply mixing detection device for a railway signal power supply panel according to claim 7, characterized in that: A resistor R24 ​​and a common-mode suppressor L1 are connected in parallel between CANH and CANL of the CAN communication module.

9. A power supply mixing detection device for a railway signal power supply panel according to claim 7 or 8, characterized in that: The CAN communication module uses a CAN isolation transceiver ADM3053. The analog-to-digital converter module uses an ADS1271 analog-to-digital converter chip.

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