Current type AC / DC live detection automatic grounding system

Abstract

The utility model relates to the technical field of power electronics, and discloses a current type AC / DC live detection automatic grounding system. Comprising a positive bus, a negative bus, a reactor, a resistor, a Hall current sensor, a grounding switch and a detection master control device, the input end of the reactor is connected with the positive bus, the output end of the reactor is connected with the input end of the resistor, and the output end of the resistor is connected with the negative bus. A Hall current sensor is connected in series between the output end of the resistor and the negative bus; the grounding switch input end is connected with the positive bus, and the grounding switch output end is connected with the negative bus. The system can adapt to real-time live-line detection and automatic grounding of AC / DC voltages of AC 27.5 KV, DC 1500V and DC 750V, and real-time voltage display and AC / DC characteristic display under the live-line condition by installing only one set of device; the grounding knife switch is automatically switched on, safety accidents and misoperation in the manual electricity testing and switching-on process are avoided, and the safety of the grounding working condition of a locomotive traction power supply system is effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and in particular relates to a current-type AC / DC live detection automatic grounding system for rail transit contact network. Background Art

[0002] Due to the rapid development of rail transportation, many rail locomotive manufacturing plants have been established, and each manufacturer has been equipped with a dedicated line for dynamic debugging of locomotives. The inventor found that the debugging lines of the current locomotive production plants usually use the same debugging power supply line for DC voltage DC1500V, DC750V and AC27.5KV. After the locomotive debugging is completed, the power supply line needs to be grounded to ensure safety. Before grounding, the line needs to be tested for power and the system line needs to be grounded after it is determined that the system line is not energized. At present, this method mainly has the following two problems. First, since it is a mixed AC and DC line, different test poles need to be distinguished. During the manual operation process, if the wrong test pole is used, breakdown or inaccurate power testing will occur, causing safety accidents. Secondly, if the line is found to be energized during the power test, the current real-time voltage cannot be accurately displayed. Second, since the grounding knife needs to be manually operated to close the switch after the power test is completed, there will be situations where the manual operation of the grounding knife is not in place or the grounding knife is not closed, causing safety hazards. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a current-type AC / DC live detection automatic grounding system, which solves the operational risks in the process of power testing and grounding knife closing.

[0004] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0005] A current-type AC / DC live detection automatic grounding system includes a positive bus, a negative bus, a reactor, a resistor, a Hall current sensor, a grounding switch, and a detection main control device. The input end of the reactor is connected to the positive bus, the output end of the reactor is connected to the input end of the resistor, the output end of the resistor is connected to the negative bus, and the Hall current sensor is connected in series between the output end of the resistor and the negative bus.

[0006] The input end of the grounding switch is connected to the positive bus, and the output end of the grounding switch is connected to the negative bus;

[0007] The input end of the detection main control device collects the current signal of the Hall current sensor, and the output end controls the opening and closing of the grounding switch.

[0008] Furthermore, in the above solution, the Hall current sensor is used to collect real-time current of the circuit.

[0009] Furthermore, in the above solution, when the system input voltage is DC 1500V or DC 750V, the reactor in the system has no inductive reactance effect on the DC, and only the reactor's own impedance.

[0010] Furthermore, when the system input voltage is AC27.5kV, the reactor in the system is composed of its own inductive reactance voltage and impedance voltage; the real-time current collected by the Hall current sensor is used to calculate the current system bus total voltage.

[0011] Furthermore, in the above solution, the detection main control device includes a control output module, an AD current sampling module, a display module and a controller.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The utility model realizes automatic live detection of AC and DC voltages. Only one set of devices is required to adapt to real-time live detection and automatic grounding of AC and DC voltages of AC27.5KV, DC1500V and DC750V, as well as real-time voltage display and AC and DC characteristic display under live conditions. It realizes automatic closing of the grounding knife, avoids safety accidents and misoperation during manual power testing and closing, and effectively improves the safety of the grounding working condition of the locomotive traction power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the utility model;

[0015] Figure 2 This is a control flow chart of the utility model;

[0016] Among them: 1. Positive bus; 2. Negative bus; 3. Reactor; 4. Resistor; 5. Hall current sensor; 6. Grounding switch; 7. Detection main control device. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] The present invention will be further described with reference to the accompanying drawings and embodiments:

[0019] Example 1:

[0020] A current-type AC / DC live detection automatic grounding system, reference Figure 1-Figure 2As shown, it includes a positive bus 1, a negative bus 2, a reactor 3, a resistor 4, a Hall current sensor 5, a grounding switch 6 and a detection main control device 7; the input end of the reactor 3 is connected to the positive bus 1, the output end of the reactor 3 is connected to the input end of the resistor 4, the output end of the resistor 4 is connected to the negative bus 2, and the Hall current sensor 5 is connected in series between the output end of the resistor 4 and the negative bus 2;

[0021] The input end of the grounding switch 6 is connected to the positive bus 1, and the output end of the grounding switch 6 is connected to the negative bus 2;

[0022] The input end of the detection main control device 7 collects the current signal of the Hall current sensor 5, and the output end controls the opening and closing of the grounding switch 6.

[0023] In this embodiment, the detection main control device 7 includes a control output module, a display module, an AD current sampling module and a microcontroller MCU;

[0024] Specifically, the control output module includes components such as a drive circuit, a power amplifier circuit, and a relay. The drive circuit receives control signals from the microcontroller and converts them into signals suitable for processing by the power amplifier circuit. The power amplifier circuit amplifies the drive signal to provide sufficient power to drive the relay. The relay acts as an actuator to control the opening and closing of the earthing switch.

[0025] This module receives control commands from the microcontroller (MCU) and controls the state of grounding switch 6 based on pre-set logic and detection results. When the system detects a need for grounding, the control output module drives a relay to close grounding switch 6, short-circuiting the positive bus 1 and the negative bus 2 to achieve grounding and preventing further bus power transmission. When the system receives a bus power transmission request, the control output module controls the relay to open, disconnecting grounding switch 6 and restoring the system to normal operation.

[0026] Specifically, the AD current sampling module consists of a signal conditioning circuit, an A / D converter, and an interface circuit. The signal conditioning circuit filters, amplifies, and isolates the analog current signal output by the Hall effect current sensor to improve signal quality and stability. The A / D converter converts the conditioned analog signal into a digital signal for processing by the microcontroller (MCU). The interface circuit facilitates data transmission and communication between the A / D converter and the MCU.

[0027] This module collects the current signal output by the Hall effect current sensor in real time and converts it into a digital signal that can be recognized by the microcontroller. By accurately sampling and converting the current signal, it provides the system with accurate current data for the microcontroller MCU to analyze and judge the data, thereby enabling system operation status monitoring and fault diagnosis.

[0028] Specifically, the display module utilizes an LCD screen to intuitively display the system's operating status, test data, and fault information. This allows operators to view real-time system parameters, such as current level and grounding switch status, for convenient system monitoring and operation. Furthermore, when a system fault occurs, the display module promptly displays the fault type and related information, helping maintenance personnel quickly locate and troubleshoot the problem.

[0029] Specifically, the microcontroller MCU is the core of the detection main control device 7. It is responsible for receiving the current data collected by the AD current sampling module, analyzing and processing it, and judging whether the system needs to be grounded based on preset algorithms and logic. It then issues corresponding control instructions to the control output module. At the same time, the microcontroller MCU is also responsible for managing the display module, sending the information to be displayed to the display module for display. In addition, the microcontroller MCU works in conjunction with other auxiliary circuits to ensure the stable operation of the entire detection main control device. The microcontroller MCU can be a high-performance 32-bit ARM Cortex-M series microcontroller.

[0030] In this embodiment, the inductive reactance of the reactor 3 is Lr, the impedance of the reactor 3 is Rr0, and the impedance of the resistor 4 is Rr1. The characteristic of the reactor 3 that it blocks direct current is used.

[0031] like Figure 1 As shown, a Hall current sensor 5 is connected in series between the output end of the resistor 4 and the negative bus 2 , and the Hall current sensor 5 is used to collect the real-time current of the line.

[0032] When the system input voltage is 1500V DC or 750V DC, the system reactor 3 has no inductive reactance to DC, only its own impedance Rr0. Therefore, the current total system bus voltage U is calculated using the real-time current I1 collected by the Hall effect current sensor 5 as: U = (I1 × Rr0) + (I1 × Rr1). The detection main control device 7 determines that the DC is live and displays the real-time DC voltage.

[0033] When the system input voltage is AC27.5kV, the reactor 3 in the system is composed of its own inductive reactance voltage and impedance voltage. Therefore, the real-time current I2 collected by the Hall current sensor 5 is used to calculate the current system bus total voltage U:

[0034] Impedance voltage U1=(I2×Rr0)+(I2×Rr1);

[0035] Inductive reactance voltage U2 = I2 × Lr;

[0036] Total bus voltage ;

[0037] The system determines that the AC is energized and displays the real-time voltage.

[0038] If the total system bus voltage is not zero, the system prohibits closing of grounding switch 6. If the total system bus voltage is zero, grounding switch 6 will automatically close after a delay.

[0039] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A current-type AC / DC live detection automatic grounding system, characterized in that: It includes a positive bus, a negative bus, a reactor, a resistor, a Hall current sensor, a grounding switch and a detection main control device. The input end of the reactor is connected to the positive bus, the output end of the reactor is connected to the input end of the resistor, the output end of the resistor is connected to the negative bus, and the Hall current sensor is connected in series between the output end of the resistor and the negative bus. The input end of the grounding switch is connected to the positive bus, and the output end of the grounding switch is connected to the negative bus; The input end of the detection main control device collects the current signal of the Hall current sensor, and the output end controls the opening and closing of the grounding switch.

2. A current-type AC / DC live detection automatic grounding system according to claim 1, characterized in that: The Hall current sensor is used to collect the real-time current of the circuit.

3. The current-type AC / DC live detection automatic grounding system according to claim 1, characterized in that: When the system input voltage is DC1500V or DC750V, the reactor in the system has no inductive reactance effect on the DC current, only the reactor's own impedance.

4. The current-type AC / DC live detection automatic grounding system according to claim 1, characterized in that: When the system input voltage is AC27.5kV, the reactor in the system is composed of its own inductive reactance voltage and impedance voltage; the real-time current collected by the Hall current sensor is used to calculate the current system bus total voltage.

5. The current-type AC / DC live detection automatic grounding system according to claim 1, characterized in that: The detection main control device includes a control output module, an AD current sampling module, a display module and a microcontroller MCU.

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