A charging pile testing interface cable and a DC charging pile fault detector

Abstract

This invention discloses a charging pile detection interface cable and a DC charging pile fault detector. The cable includes a cable body and an interface; the cable body includes an axially extending conductor covered with an insulation layer and an outer shielding layer, housed within an outer sheath; the interface is installed at the end of the cable body and has a female connector that is in communication with the corresponding conductor; at least one of the female connectors has a non-contact protective branch, which is connected to a sampling capacitor, the other side of which is connected to the cable grounding terminal; the sampling capacitor is connected in parallel with a light-emitting diode. The DC charging pile fault detector includes the charging pile detection interface cable. The charging pile detection interface cable and DC charging pile fault detector provided by this invention, through the non-contact protective branch located on the interface female connector, sense abnormally energized charging piles, eliminating high-voltage leakage abnormalities before connecting the DC charging pile and the DC charging pile fault detector.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, and more specifically, relates to a charging pile testing interface cable and a DC charging pile fault detector. Background Technology

[0002] Electric vehicle charging pile technology is categorized by current type into AC slow charging and DC fast charging. AC charging piles use on-board chargers with a power of 7-22kW and a voltage of 220V / 380V, suitable for home overnight charging. DC charging piles have built-in rectifier modules with a power of 60-480kW and a voltage of 200-1000V, enabling direct fast charging of batteries. In terms of power development, early 60kW DC charging piles have been gradually replaced by 120-180kW piles. From 2023 onwards, liquid-cooled supercharging piles of 350kW and above have become standard equipment in newly built public charging stations, with companies such as Huawei and Tesla launching 600kW sub-megawatt solutions. By 2025, a key technological breakthrough is expected: BYD will release the world's first mass-produced megawatt-level (1000kW) flash charging technology for passenger vehicles, employing a 1000V high-voltage platform and a 1000A ultra-high current, enabling a range of 400 kilometers with just 5 minutes of charging, truly achieving "same speed for gasoline and electric vehicles." Currently, China has over 9 million charging piles, with high-voltage fast charging and megawatt-level technology developing in parallel. However, high-power equipment places higher technical demands on grid load, heat dissipation systems, and battery thermal management.

[0003] As the power of electric vehicle charging piles leaps from 7kW to 1000kW megawatts, and the voltage platform rises from 220V to 1000V high voltage, the risk of charging facility failure increases significantly. High power density leads to thermal runaway of components, accelerated insulation aging, and frequent hidden dangers such as leakage in liquid cooling systems and wear of charging cables. DC charging pile fault detectors can identify dangers such as overvoltage, overcurrent, and grounding faults in milliseconds by monitoring voltage and current waveforms, temperature field distribution, and insulation resistance changes in real time, thus preventing battery thermal runaway and fire accidents.

[0004] With the widespread adoption of megawatt-level fast charging, intelligent fault detection has become a necessary technological barrier for the safe operation of charging infrastructure. During inspections, using charging pile testers is crucial for ensuring the safety of inspection personnel and the healthy operation of the charging piles. However, charging piles requiring inspection are more likely to experience high-voltage electric shocks and arcing. When connecting charging pile cables for testing, this can cause damage to the testing equipment, or in severe cases, lead to safety accidents, threatening the lives and safety of inspection personnel. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a charging pile testing interface cable and a DC charging pile fault detector. The purpose is to add a non-contact protective branch to the end interface of the charging pile testing interface cable. This non-contact sensing of DC charging pile leakage through sampling capacitors prevents abnormal charging of faulty DC charging piles from causing safety accidents during fault detection. This solves the current technical problem of safety hazards posed by faulty DC charging piles, which could damage testing instruments or even endanger the lives and safety of inspection personnel.

[0006] To achieve the above objectives, according to one aspect of the present invention, a charging pile detection interface cable is provided, comprising a cable body and an interface; The cable body includes an axially extending conductor, which is covered with an insulation layer and an outer shielding layer, and is housed within an outer sheath. The interface is installed at the end of the cable body and has a female connector that is in communication with the corresponding conductor; At least one of the female connectors of the interface has a non-contact protection branch, the non-contact protection branch is connected to a sampling capacitor, and the other side of the sampling capacitor is connected to the grounding terminal of the cable; the sampling capacitor is connected in parallel with a light-emitting diode.

[0007] Preferably, the charging pile detection interface cable has a window at the cable body or interface; the light-emitting diode is located below the window, and the light signal of the light-emitting diode is observed through the window.

[0008] Preferably, the charging pile detection interface cable has a viewing window in the cable body; the non-contact protective branch is located inside the cable body shielding layer, and the shielding layer at the viewing window is perforated at the corresponding position so that the light signal of the light-emitting diode is emitted laterally.

[0009] Preferably, in the charging pile detection interface cable, a high-voltage isolation capacitor is connected in series between the female connector and the sampling capacitor.

[0010] Preferably, in the charging pile detection interface cable, the sampling capacitor and the high-voltage isolation capacitor are voltage divided in a ratio of 1:50 to 100.

[0011] Preferably, the high-voltage isolation capacitor of the charging pile detection interface cable has a capacitance value of 1~100pF.

[0012] Preferably, the forward voltage of the light-emitting diode in the charging pile detection interface cable is 0.7V or 0.3V.

[0013] Preferably, the charging pile detection interface cable has a DC positive terminal female connector, and the DC positive terminal female connector has a non-contact protective branch.

[0014] According to another aspect of the present invention, a DC charging pile fault detector is provided, which has the charging pile detection interface cable provided by the present invention.

[0015] Preferably, the DC charging pile fault detector has a DC positive terminal female connector on the interface of the charging pile detection interface cable, and the DC positive terminal female connector has a non-contact protection branch. The DC positive characteristic signal acquisition path of the DC charging pile fault detector is connected in parallel with the sampling capacitor. The DC positive characteristic signal acquired by the detector is analyzed by the processor to detect faults in the charging pile.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: The charging pile testing interface cable and DC charging pile fault detector provided by this invention, through the non-contact protective branch set in the interface female, senses abnormal energization of the faulty charging pile, eliminates high voltage leakage abnormalities before connecting the DC charging pile and the DC charging pile fault detector, and performs systematic fault detection and analysis under the premise of ensuring the life and safety of inspection personnel and avoiding damage to the instrument, thereby maintaining the charging pile and providing a safety guarantee for the market promotion of fast charging and supercharging charging piles. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the charging pile detection interface cable structure provided by the present invention; Figure 2 This is a schematic diagram of the end face of the charging pile detection interface cable interface from direction A, provided by the present invention. Figure 3 This is a schematic diagram of the cross-sectional structure of the charging pile detection interface cable provided in an embodiment of the present invention.

[0018] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1 is an interface, 101 is a DC positive female connector DC+, 102 is a DC negative female connector DC-, 103 is a charging connection confirmation female connector CC1, 104 is a charging connection confirmation female connector CC2, 105 is a CAN communication positive female connector S+, 106 is a CAN communication negative female connector S-, 107 is an auxiliary power positive female connector A+, 108 is an auxiliary power negative female connector A-, 109 is a protective grounding female connector PE, 2 is the cable body, 201 is a DC positive conductor DC+, 202 is a DC positive conductor DC+, 202 is a DC negative conductor DC+, 202 is a DC positive ... 203 is the DC negative conductor (DC-), 204 is the charging connection confirmation conductor (CC1), 205 is the charging connection confirmation conductor (CC2), 206 is the CAN communication positive conductor (S+), 207 is the CAN communication negative conductor (S-), 208 is the auxiliary power positive conductor (A+), 209 is the auxiliary power negative conductor (A-), 210 is the protective grounding conductor (PE), 211 is the flame-retardant polypropylene rope, 212 is the shielding layer, 213 is the inorganic fireproof layer, 214 is the outer sheath, 215 is the sampling capacitor, 216 is the light-emitting diode, 217 is the high-voltage isolation capacitor, and 218 is the viewing window. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] The charging pile testing interface cable provided by this invention, such as Figure 1 As shown, it includes the cable body and the interface; The cable body includes an axially extending conductor, which is covered with an insulation layer, wrapped with a shielding layer on the outside, and housed in an outer sheath; The interface is installed at the end of the cable and has a female connector that is connected to the corresponding conductor. At least one of the female connectors has a non-contact protection branch for non-contact leakage and abnormal current detection. The non-contact protection branch is connected to a sampling capacitor, the other side of which is grounded. The sampling capacitor is connected in parallel with a light-emitting diode (LED). The sampling capacitor, through the female connector, can sense the potential change at the interface location. When the interface is near the charging gun socket but not yet connected, it performs non-contact safety detection on the DC charging gun voltage. If the DC charging gun voltage leaks, the sampling capacitor generates an induced current, and the LED connected in parallel provides a visual light signal alarm. Before connecting the charging gun for electrical performance testing of the charging pile, inspection personnel can observe abnormal voltage, avoiding high-voltage electric shock and arc discharge, ensuring the health and safety of inspection personnel, and preventing damage to fault detection instruments. For convenient visual observation, the LED is preferably positioned below the viewing window, through which the LED's light signal is observed. The viewing window can be located near the interface on the cable or directly at the interface.

[0021] In a preferred embodiment, a high-voltage isolation capacitor is connected in series between the female connector and the sampling capacitor to reduce non-fault voltage and potential fault high voltage. The high-voltage isolation capacitor and the sampling capacitor are divided in a voltage ratio of 1:50 to 100 to prevent high voltage from damaging the components of the charging pile fault detector, while ensuring the signal-to-noise ratio of the characteristic signal. The capacitance value of the high-voltage isolation capacitor is 1 to 100 pF, preferably 47 pF; the capacitance value of the sampling capacitor is preferably 4700 pF, to drive the diode to emit light and provide the characteristic signal required for system detection.

[0022] Typically, the non-contact protection branch is connected to the positive DC female terminal of the interface, such as... Figure 2 As shown, the DC positive pin of the charging gun is most likely to experience high voltage leakage, leading to arc discharge. Therefore, the DC positive female connector of the charging pile detection interface cable is most likely to sense a dangerous potential difference. Connecting the non-contact protection branch to the DC positive female connector will maximize the protection effect.

[0023] When the DC charging pile fault detector interacts with the DC charging pile, if there is voltage leakage, the interface socket non-contactly senses the voltage. When the voltage drop across the sampling capacitor exceeds the conduction voltage of the LED, the LED emits a light signal, which can be observed by the inspection personnel through the viewing window. The detection is terminated before the charging gun pins make physical contact with the socket, thus achieving non-contact protection and avoiding risks to personnel and property.

[0024] The cable's shielding layer serves the same purpose as that of a standard DC charging pile cable: shielding against interference signals. Placing the non-contact protection branch inside the cable's shielding layer further reduces signal interference to this branch, preventing false alarms. In this design, a viewing window is preferably placed in the cable body for easier component placement in the non-contact protection branch. Perforations are made in the shielding layer at corresponding positions around the viewing window, allowing the light signal from the LED to be emitted laterally and thus observed.

[0025] The DC charging pile fault detector provided by this invention features a charging pile detection interface cable for connecting to the charging gun of the charging pile. A non-contact protection branch samples from the female connector of the interface, collecting characteristic signals for fault detection. Typically, the non-contact protection branch collects DC positive characteristic signals from the positive DC connector of the female connector, which are then analyzed by the detection module to detect faults in the charging pile.

[0026] When using the DC charging pile fault detector provided by this invention, the inspection personnel hold the charging pile detection interface cable and bring its interface close to the charging gun of the DC charging pile to be tested. If the LED emits a light signal alarm, the fault detector connection is terminated to confirm the leakage situation. If the LED does not emit a light signal, the DC charging pile charging gun is connected. The signals of each pin of the charging gun are directly connected to the charging pile detection interface or connected to the detection module after signal acquisition. The processor of the detection module analyzes the signals, performs comprehensive measurement and evaluation of the charging pile, and displays the corresponding fault code after determining the fault. Generally, the DC positive terminal female connector collects the DC positive characteristic signal through the high-voltage isolation capacitor and connects it to the detection module. The DC negative terminal female connector, charging connection confirmation female connector, CAN communication positive and negative terminal female connectors, auxiliary power supply positive and negative terminal female connectors, and protective grounding female connector are directly connected to the detection module.

[0027] The following is an example: This embodiment applies to fast charging and supercharging charging piles. The charging pile detection interface cable provided in this embodiment is as follows: Figure 1 As shown, it includes the cable body and the interface; The cross-section of the cable body is as follows Figure 3 As shown, it includes an axially extending conductor, which is covered with an insulating layer, wrapped with a shielding layer on the outside, and housed in an outer sheath. In this embodiment, the cable body is a 9-core cable. The conductors include: 35-95mm² DC positive and negative conductors (DC+, DC-), 0.5-1.0mm² charging connection confirmation conductors (CC1, CC2), 0.5-0.75mm² CAN communication positive and negative conductors (S+, S-), 1.0-2.5mm² auxiliary power positive and negative conductors (A+, A-), and 16-50mm² protective grounding conductor (PE). The conductor material is pure copper, and the insulation layer covering the conductors is made of thermoplastic elastomer (TPE). A flame-retardant polypropylene rope is added to fill the rounded, twisted bundle, and wrapped with a copper wire braided shielding layer. A polyether-based TPU outer sheath is set on the outside of the shielding layer. In addition, the DC positive and negative conductors have independent aluminum-plastic composite tape shielding layers, and the CAN communication positive and negative conductors have independent aluminum foil shielding layers. Optionally, the inner side of the shielding layer is filled with aramid reinforcement, nylon braided layer, inorganic fireproof material layer (e.g., silicate fiber), etc.

[0028] The interface is installed at the end of the cable body, such as... Figure 2 As shown, the device has female connectors that are connected to the corresponding conductors: DC positive and negative female connectors (DC+, DC-), charging connection confirmation female connectors (CC1, CC2), CAN communication positive and negative female connectors (S+, S-), auxiliary power supply positive and negative female connectors (A+, A-), and protective grounding female connectors (PE). The female connector contacts are gold-plated to improve conductivity stability and corrosion resistance.

[0029] The DC positive terminal (DC+) has a non-contact protection branch, which connects a high-voltage isolation capacitor and a sampling capacitor in series. The high-voltage isolation capacitor is used to isolate the high voltage generated when the charging pile malfunctions. In this embodiment, the capacitance of the high-voltage isolation capacitor is 47pF for easy debugging. The sampling capacitor is connected in parallel with a light-emitting diode to provide voltage division for the isolation capacitor and trigger the diode alarm. In this embodiment, the capacitance of the sampling capacitor is 4700pF. The other side of the sampling capacitor is grounded. In this embodiment, the grounding terminal is directly connected to the protective grounding conductor (PE). In this embodiment, the voltage of the DC positive terminal is stepped down by 100:1 and used as a characteristic signal. In case of abnormality, it drives the diode alarm. In case of normal operation, it sends the characteristic signal to the CPU of the detection module for system analysis of the charging pile.

[0030] In this embodiment, the LED is positioned below the interface window for easy observation when inspectors attempt to connect the charging gun. Once illuminated, the LED emits light through the window and triggers an alarm. A window is required at the location of the LED on the outer sheath, with corresponding holes drilled in the shielding layer at the window location. A non-contact protection branch is located inside the cable's shielding layer. The LED emits signal light from the holes in the shielding layer, which is observed by inspectors. In this embodiment, the LED's forward voltage is 0.3V. An alarm is triggered when the non-contact induced voltage is ≥30V.

[0031] The charging pile detection interface cable provided in this embodiment is used as a connector for a DC charging pile fault detector. The DC positive characteristic signal acquisition path of the DC charging pile fault detector is connected in parallel with the sampling capacitor. The DC positive characteristic signal acquired by the detector is connected to the detection module. The DC negative terminal socket, charging connection confirmation socket, CAN communication positive and negative terminal sockets, auxiliary power positive and negative terminal sockets, and protective grounding socket are directly connected to the detection module. The processor (CPU) of the detection module performs comprehensive measurement and evaluation of the signal and displays the corresponding fault code.

[0032] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A charging pile testing interface cable, characterized in that, Including the cable body and the connector; The cable body includes an axially extending conductor, which is covered with an insulation layer and an outer shielding layer, and is housed within an outer sheath. The interface is installed at the end of the cable body and has a female connector that is in communication with the corresponding conductor; At least one of the female connectors of the interface has a non-contact protection branch, the non-contact protection branch is connected to a sampling capacitor, and the other side of the sampling capacitor is connected to the grounding terminal of the cable; the sampling capacitor is connected in parallel with a light-emitting diode.

2. The charging pile testing interface cable as described in claim 1, characterized in that, A viewing window is provided at the cable body or interface; the light-emitting diode is located below the viewing window, and the light signal of the light-emitting diode is observed through the viewing window.

3. The charging pile testing interface cable as described in claim 2, characterized in that, A viewing window is provided in the cable body; the non-contact protective branch is located inside the cable body shielding layer, and holes are punched in the shielding layer at the corresponding position of the viewing window so that the light signal of the light-emitting diode is emitted laterally.

4. The charging pile testing interface cable as described in claim 1, characterized in that, A high-voltage isolation capacitor is connected in series between the female connector and the sampling capacitor.

5. The charging pile testing interface cable as described in claim 4, characterized in that, The sampling capacitor and the high-voltage isolation capacitor are divided in a voltage ratio of 1:50 to 100.

6. The charging pile testing interface cable as described in claim 4, characterized in that, The capacitance value of the high-voltage isolation capacitor is between 1 and 100 pF.

7. The charging pile testing interface cable as described in claim 1, characterized in that, The forward voltage of the light-emitting diode is 0.7V or 0.3V.

8. The charging pile testing interface cable as described in claim 1, characterized in that, The interface has a DC positive terminal female connector, and the DC positive terminal female connector has a non-contact protective branch.

9. A DC charging pile fault detector, characterized in that, The charging pile testing interface cable is as described in any one of claims 1 to 8.

10. The DC charging pile fault detector as described in claim 9, characterized in that, The interface of the charging pile detection interface cable has a DC positive female connector, and the DC positive female connector has a non-contact protection branch. The DC positive characteristic signal acquisition path of the DC charging pile fault detector is connected in parallel with the sampling capacitor. The DC positive characteristic signal acquired by the detector is analyzed by the processor to detect faults in the charging pile.

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