Excitation protection circuit for industrial and mining diesel locomotive

Abstract

The present application relates to a kind of industrial internal combustion locomotive excitation protection circuit, belong to industrial internal combustion locomotive electrical control system technical field, including: excitation device, the positive pole of the excitation device is connected with the cathode of arc extinguishing device by contactor, the negative pole of the excitation device is connected with the anode of arc extinguishing device;Excitation winding, one end of the excitation winding is connected with the cathode of arc extinguishing device, the other end of the excitation winding is connected with the anode of arc extinguishing device.The present application can eliminate arc and voltage peak when excitation loop is disconnected by using arc extinguishing device, protect excitation contactor contact and power semiconductor switch, reduce electromagnetic interference, prolong equipment life.

Description

Technical Field

[0001] This invention relates to the field of electrical control system technology for industrial and mining diesel locomotives, specifically to an excitation protection circuit for industrial and mining diesel locomotives. Background Technology

[0002] During frequent start-stop operations, diesel locomotives in mining and industrial settings experience high-voltage back electromotive force (EMF) generated by electromagnetic induction when the large inductive load in the excitation winding is turned off. This EMF can reach 5-10 times the operating voltage, causing arcing and burning of the excitation contactor contacts, breakdown of power semiconductor devices, and equipment failure. Traditional fuse overcurrent protection has a delayed response and cannot effectively solve the problem of transient high voltage, leading to an increased locomotive repair rate. A low-cost, high-reliability dynamic protection scheme is needed. In actual operation, due to the complex mining environment, locomotives are frequently in a high-load, high-frequency start-stop state, resulting in drastic current changes in the excitation circuit, which can easily generate extremely high self-induced EMF at the moment of disconnection. This transient high voltage not only damages contactor contacts and power devices but also causes electromagnetic interference to the entire vehicle's electrical system, affecting the normal operation of other electronic equipment. Currently available protection measures such as absorption circuits and varistors have some effect, but they still suffer from slow response speed, short lifespan, high cost, or poor adaptability. Especially under the dusty and high-vibration conditions of mining environments, the reliability of these protection devices is further reduced. Furthermore, existing technologies lack effective status indication functions, making it difficult for maintenance personnel to promptly understand the operating status of protection devices, often resulting in accidents where the excitation device burns out during power outages. Therefore, there is an urgent need for an excitation protection circuit that can respond in real time, operate reliably, and is easy to maintain, in order to improve the overall operational reliability and economy of locomotives. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide an excitation protection circuit for industrial and mining diesel locomotives.

[0004] An excitation protection circuit for an industrial and mining diesel locomotive includes:

[0005] An excitation device, wherein the positive terminal of the excitation device is connected to the cathode of the arc-extinguishing device via a contactor, and the negative terminal of the excitation device is connected to the anode of the arc-extinguishing device;

[0006] An excitation winding, one end of which is connected to the cathode of the arc-extinguishing device, and the other end of which is connected to the anode of the arc-extinguishing device.

[0007] Preferred options also include:

[0008] A fast-blow fuse is provided, with one end connected to the cathode of the arc-extinguishing device and the other end connected to the negative terminal of the excitation device.

[0009] Preferred options also include:

[0010] A voltage monitoring indicator light, one end of which is connected to one end of the excitation winding, and the other end of which is connected to the other end of the excitation winding.

[0011] Preferably, the arc-extinguishing device is a diode.

[0012] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0013] This invention relates to an excitation protection circuit for industrial and mining diesel locomotives. Compared with the prior art, this invention can eliminate electric arcs and voltage spikes when the excitation circuit is disconnected by using an arc-extinguishing device, thereby protecting the excitation contactor contacts and power semiconductor switches, reducing electromagnetic interference, and extending equipment life.

[0014] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This invention provides an excitation protection circuit diagram for an industrial and mining diesel locomotive. Detailed Implementation

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] Please see Figure 1 An excitation protection circuit for an industrial and mining diesel locomotive includes:

[0021] An excitation device, wherein the positive terminal of the excitation device is connected to the cathode of the arc-extinguishing device via a contactor, and the negative terminal of the excitation device is connected to the anode of the arc-extinguishing device;

[0022] An excitation winding, one end of which is connected to the cathode of the arc-extinguishing device, and the other end of which is connected to the anode of the arc-extinguishing device.

[0023] Furthermore, it also includes:

[0024] A fast-blow fuse is provided, with one end connected to the cathode of the arc-extinguishing device and the other end connected to the negative terminal of the excitation device.

[0025] A voltage monitoring indicator light, one end of which is connected to one end of the excitation winding, and the other end of which is connected to the other end of the excitation winding.

[0026] In practical applications, the cathode of the arc extinguishing device (D) is connected to the positive terminal of the excitation power supply, the anode is connected to the output terminal of the excitation winding, a series fast-blow fuse (FU) is used as a secondary overcurrent protection, and a voltage monitoring indicator (LED) is connected in parallel for status visualization.

[0027] The working process is as follows: Normally, when the excitation contactor K is closed, current flows through contactor K to the excitation winding L. Diode D is reverse-biased (not conducting). At the moment of turn-off, contactor K opens, generating a reverse high voltage in the excitation winding L. Diode D then conducts in the forward direction, forming a freewheeling circuit: "L1→D→L2". This converts the inductor's stored energy into heat energy, clamping the voltage below 1V (diode forward voltage drop). Status feedback: When the diode is conducting, an LED illuminates to indicate the protection action.

[0028] It should be noted that the arc extinguishing device is a DF-J0022A type arc extinguishing device, with a withstand voltage greater than twice the excitation voltage and a current greater than the peak value of the excitation current. The fuse is an RT18 type fast-blow fuse (operating time <1ms). The indicator light is a DC 110V LED warning light.

[0029] Installation method: Locate the positive terminal 317 below the excitation contactor K and connect it to the cathode of the arc extinguishing device. Connect a fast-blow fuse FU in series with the anode of the arc extinguishing device. Connect the other end of FU to the negative terminal 318. Connect the two thick red wires of the excitation coil. Connect the voltage monitoring LED directly in parallel to the excitation winding terminals. Embed the indicator light in the fault display panel on the driver's control panel.

[0030] Example working scenario: When the locomotive is unloaded, the excitation contactor K disconnects for protection: The excitation winding L generates a reverse high voltage, the diode D conducts instantaneously, and the freewheeling current path is "L1→D→L2". The voltage is clamped to 0.7V, the contactor K disconnects without arcing, and the LED lights up for 3 seconds (energy storage release time) before turning off.

[0031] Benefit verification: After installing this circuit on locomotive 5248, the maintenance cycle of the excitation device was extended from 2 months to more than 1 year, and the failure rate of the excitation circuit decreased by more than 60%. The number of excitation devices burned out due to electrical faults decreased by 2 per year, saving more than 90,000 yuan.

[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An excitation protection circuit for an industrial and mining diesel locomotive, characterized in that, include: An excitation device, wherein the positive terminal of the excitation device is connected to the cathode of the arc-extinguishing device via a contactor, and the negative terminal of the excitation device is connected to the anode of the arc-extinguishing device; An excitation winding, one end of which is connected to the cathode of the arc-extinguishing device, and the other end of which is connected to the anode of the arc-extinguishing device.

2. The excitation protection circuit for an industrial and mining diesel locomotive according to claim 1, characterized in that, Also includes: A fast-blow fuse is provided, with one end connected to the cathode of the arc-extinguishing device and the other end connected to the negative terminal of the excitation device.

3. The excitation protection circuit for an industrial and mining diesel locomotive according to claim 2, characterized in that, Also includes: A voltage monitoring indicator light, one end of which is connected to one end of the excitation winding, and the other end of which is connected to the other end of the excitation winding.

4. The excitation protection circuit for an industrial and mining diesel locomotive according to claim 3, characterized in that, The arc-extinguishing device is a diode.

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