Ground wire disconnection detection device

Abstract

The invention relates to a grounding wire disconnection detection device which comprises a voltage detection module, a disconnection detection module and a control module. Wherein a first input end of the voltage detection module is used for being connected with a zero line of a charging pile, a second input end of the voltage detection module is connected with a grounding line of the charging pile, an output end of the voltage detection module is connected with a control input end of the disconnection detection module, and a power supply input end of the disconnection detection module is used for being connected with a power supply. The output end of the offline detection module is connected with the control module; the disconnection detection module is used for responding to a first detection signal which is output by the voltage detection module and represents that the grounding wire is in a disconnection state, outputting a disconnection pulse signal to the control module, and responding to a second detection signal which is output by the voltage detection module and represents that the grounding wire is in a non-disconnection state; according to the technical scheme provided by the invention, whether the grounding wire is disconnected or not can be detected in real time, and the grounding wire disconnection detection precision is improved.

Description

Technical Field

[0001] This application relates to the field of disconnection detection technology for electrical systems of charging piles, and in particular to a grounding wire disconnection detection device. Background Technology

[0002] With the explosive growth of the new energy vehicle industry, charging piles, as core supporting facilities, have seen rapid expansion in deployment. As high-power outdoor electrical equipment, the safe operation of charging piles is crucial. The integrity of the protective grounding (PE) circuit is the core guarantee for preventing leakage and avoiding the risk of electric shock. However, charging piles are located outdoors for a long time and are affected by high temperature, humidity, rain, and vehicle collisions. PE terminals are prone to corrosion, and cable joints are prone to loosening and breakage. In some cases, improper construction of the grounding grid (excessive grounding resistance, oxidation of the grounding electrode) or misoperation during operation and maintenance (missing to connect the PE wire after maintenance) can also lead to PE circuit failure.

[0003] Furthermore, current charging pile PE circuit detection solutions include the following two types: one is manual periodic inspection, relying on a multimeter to measure grounding resistance or PE terminal continuity. However, this method is inefficient and cannot cover a large-scale charging pile network. It also carries the risk of "faults being missed during the inspection interval." If a PE disconnection occurs between two inspections, the charging pile may operate without protection, and a leakage could lead to a safety accident. The other method is to monitor the current in series with a sampling resistor in the PE circuit. However, the above method can only indirectly determine whether the PE circuit is conducting when a leakage fault occurs. It cannot perform routine pre-detection and is considered a "post-event response," which is not safe enough. Moreover, the sampling resistor will affect the grounding impedance of the PE circuit, which does not comply with the mandatory standard in GB / T 18487.1-2015 that "the PE circuit impedance must be less than 0.1Ω," thus increasing safety hazards. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a technical solution for a grounding wire disconnection detection device. Specifically, this application includes a voltage detection module, a disconnection detection module, and a control module. The disconnection detection module, in response to a first detection signal indicating the grounding wire is disconnected (output from the voltage detection module), outputs a disconnection pulse signal to the control module. Conversely, the disconnection detection module, in response to a second detection signal indicating the grounding wire is not disconnected (output from the voltage detection module), outputs a high-level signal to the control module. When the control module detects a change in the level signal from high to a disconnection pulse signal, it issues an alarm signal. This allows for real-time detection of grounding wire disconnection, improving the accuracy of grounding wire disconnection detection. Furthermore, it exhibits strong anti-interference capabilities, high compatibility, and does not affect the impedance of the grounding wire circuit, thereby ensuring the safe operation of the charging pile.

[0005] This application provides a grounding wire disconnection detection device, including a voltage detection module, a disconnection detection module, and a control module; The first input terminal of the voltage detection module is used to connect to the neutral wire of the charging pile, the second input terminal of the voltage detection module is connected to the ground wire of the charging pile, the output terminal of the voltage detection module is connected to the control input terminal of the disconnection detection module, the power supply input terminal of the disconnection detection module is used to connect to the power supply, and the output terminal of the disconnection detection module is connected to the control module. The disconnection detection module is used to output a disconnection pulse signal to the control module in response to a first detection signal output by the voltage detection module indicating that the grounding wire is in a disconnection state. The disconnection detection module is also used to output a high-level signal to the control module in response to a second detection signal output by the voltage detection module indicating that the grounding wire is in a non-disconnection state.

[0006] Furthermore, the voltage detection module includes a capacitor voltage divider unit and a voltage detection unit; The first input terminal of the capacitor voltage divider unit is connected to the neutral wire, the second input terminal of the capacitor voltage divider unit is connected to the ground wire, the first output terminal of the capacitor voltage divider unit is connected to the first input terminal of the voltage detection unit, the second output terminal of the capacitor voltage divider unit is connected to the second input terminal of the voltage detection unit, and the output terminal of the voltage detection unit is connected to the disconnection detection module.

[0007] Furthermore, the voltage detection unit includes a voltage regulation subunit, a voltage detection subunit, and a resistive-capacitive voltage divider subunit; One end of the voltage regulator subunit is connected to the first output terminal of the capacitor voltage divider unit, the other end of the voltage regulator subunit is connected to the first terminal of the voltage detection subunit, the second terminal of the voltage detection subunit is connected to the first input terminal of the resistor-capacitor voltage divider unit, the second input terminal of the resistor-capacitor voltage divider unit is connected to the second output terminal of the capacitor voltage divider unit, and the output terminal of the resistor-capacitor voltage divider unit is connected to the input terminal of the disconnection detection module.

[0008] Furthermore, the disconnection detection module includes a disconnection protection unit and a disconnection detection unit; The input terminal of the disconnection protection unit is connected to the output terminal of the voltage detection module, the output terminal of the disconnection protection unit is connected to the control input terminal of the disconnection detection unit, the power supply input terminal of the disconnection detection unit is connected to the power supply, and the output terminal of the disconnection detection unit is connected to the control module.

[0009] Furthermore, the disconnection protection unit includes a switching subunit, a voltage clamping subunit, and a discharge subunit; The first terminal of the switch subunit is connected to the output terminal of the voltage detection module. The second terminal of the switch subunit is connected to the first terminal of the voltage clamping subunit and the first terminal of the discharge subunit. The third terminal of the switch subunit, the second terminal of the voltage clamping subunit, and the second terminal of the discharge subunit are all grounded. The third terminal of the discharge subunit is connected to the control input terminal of the disconnection detection unit.

[0010] Furthermore, the disconnection detection unit includes a first current-limiting resistor, a second current-limiting resistor, a pull-up resistor, a π-type filter circuit, and an optocoupler; One end of the first current-limiting resistor is connected to the output terminal of the disconnection protection unit, and the other end of the first current-limiting resistor is connected to the first input terminal of the optocoupler. The second input terminal of the optocoupler is connected to the power supply through the second current-limiting resistor. The first output terminal of the optocoupler is connected to one end of the pull-up resistor and the π-type filter circuit, respectively. The second output terminal of the optocoupler is grounded. The π-type filter circuit is also connected to the control module.

[0011] Furthermore, the capacitor voltage divider unit includes a first capacitor and a second capacitor; One end of the first capacitor is connected to the grounding wire, the other end of the first capacitor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the neutral wire and the voltage detection unit, respectively.

[0012] Furthermore, the voltage regulator subunit includes a third capacitor, the voltage detection subunit includes a Zener diode, and the resistor-capacitor voltage divider subunit includes a fourth capacitor, a fifth capacitor, a sixth capacitor, a first resistor, a second resistor, and a switching diode; One end of the third capacitor is connected to the capacitor voltage divider unit, and the other end of the third capacitor is connected to the negative terminal of the Zener diode. The positive terminal of the Zener diode is connected to one end of the fourth capacitor. The other end of the fourth capacitor is connected to one end of the fifth capacitor and one end of the first resistor. The other end of the first resistor is connected to one end of the sixth capacitor, the first end of the switching diode, one end of the second resistor, and the switching subunit. The other ends of the fifth capacitor, the sixth capacitor, the second and third ends of the switching diode, and the second resistor are all connected to the capacitor voltage divider unit.

[0013] Furthermore, the switching subunit includes a transistor, the voltage clamping subunit includes a bidirectional transient voltage suppressor diode, and the discharge subunit includes a seventh capacitor, an eighth capacitor, and a third resistor; The base of the transistor is connected to the voltage detection module. The collector of the transistor is connected to one end of the bidirectional transient voltage suppressor diode, one end of the seventh capacitor, one end of the eighth capacitor, one end of the third resistor, and the control input terminal of the disconnection detection unit. The emitter of the transistor, the other end of the bidirectional transient voltage suppressor diode, the other end of the seventh capacitor, the other end of the eighth capacitor, and the other end of the third resistor are all grounded. One end of the third resistor is also connected to the control input terminal of the disconnection detection unit.

[0014] Furthermore, the π-type filter circuit includes a ninth capacitor, a tenth capacitor, and a fourth resistor; The first output terminal of the optocoupler is connected to one end of the ninth capacitor and one end of the fourth resistor, respectively. The second output terminal of the optocoupler is also connected to the other end of the ninth capacitor and one end of the tenth capacitor, respectively. The other end of the tenth capacitor is connected to the other end of the ninth capacitor. The ninth capacitor and the tenth capacitor are connected in parallel.

[0015] Implementing this application will have the following beneficial effects: This application incorporates a voltage detection module, a grounding wire disconnection detection module, and a control module. The grounding wire disconnection detection module, responding to a first detection signal from the voltage detection module indicating a disconnected grounding wire, outputs a disconnection pulse signal to the control module. Conversely, the grounding wire disconnection detection module, responding to a second detection signal from the voltage detection module indicating a non-disconnected grounding wire, outputs a high-level signal to the control module. When the control module detects a change in the signal level from high to a disconnection pulse signal, it issues an alarm signal. This allows for real-time detection of grounding wire disconnection, improving the accuracy of grounding wire disconnection detection. Furthermore, it exhibits strong anti-interference capabilities, high compatibility, and does not affect the impedance of the grounding wire loop, thus ensuring the safe operation of the charging pile. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a grounding wire disconnection detection device provided in an embodiment of this application; Figure 2 The circuit diagram corresponds to a grounding wire disconnection detection device provided in the embodiments of this application.

[0018] The corresponding reference numerals in the attached figures are: 1-Voltage detection module; 11-Capacitor voltage divider unit; 111-First capacitor; 112-Second capacitor; 12-Voltage detection unit; 121-Voltage regulator subunit; 1211-Third capacitor; 122-Voltage detection subunit; 1221-Zenith diode; 123-RC voltage divider subunit; 1231-Fourth capacitor; 1232-Fifth capacitor; 1233-Sixth capacitor; 1234-First resistor; 1235-Second resistor; 1236-Switching diode; 2-Disconnection detection module; 21-Disconnection protection unit 211-Switch subunit; 2111-Transistor; 212-Voltage clamping subunit; 2121-Bidirectional transient voltage suppression diode; 213-Bleeding subunit; 2131-Seventh capacitor; 2132-Eighth capacitor; 2133-Third resistor; 22-Disconnection detection unit; 221-First current limiting resistor; 222-Second current limiting resistor; 223-Pull-up resistor; 224-π-type filter circuit; 2241-Ninth capacitor; 2242-Tenth capacitor; 2243-Fourth resistor; 225-Optical coupler; 3-Control module; 4-Charging pile. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that the terms "first," "second," etc., 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 data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0021] Please see Figure 1 and Figure 2 The following is combined with Figure 1 and Figure 2 A detailed description is provided of a grounding wire disconnection detection device provided in the embodiments of this application.

[0022] This application provides a grounding wire disconnection detection device, such as... Figure 1 and Figure 2 As shown, the system specifically includes a voltage detection module 1, a disconnection detection module 2, and a control module 3. The first input terminal of the voltage detection module 1 is connected to the neutral wire N of the charging pile 4, the second input terminal of the voltage detection module 1 is connected to the ground wire PE of the charging pile 4, the output terminal of the voltage detection module 1 is connected to the control input terminal of the disconnection detection module 2, the power supply input terminal of the disconnection detection module 2 is connected to the power supply VCC, and the output terminal of the disconnection detection module 2 is connected to the control module 3. The disconnection detection module 2, in response to a first detection signal from the voltage detection module 1 indicating that the ground wire PE is in a disconnected state, outputs a disconnection pulse signal to the control module 3. The disconnection detection module 2 also, in response to a second detection signal from the voltage detection module 1 indicating that the ground wire PE is in a non-disconnected state, outputs a high-level signal to the control module 3.

[0023] In this embodiment, the voltage detection module 1 is used to detect the voltage between the neutral wire N and the grounding wire PE in the charging pile 4, and to perform voltage division on the voltage between the neutral wire N and the grounding wire PE. Then, by detecting the voltage between the neutral wire N and the grounding wire PE in the charging pile 4, if the grounding wire PE is in a disconnected state, the voltage detection module 1 sends a first detection signal indicating that the grounding wire PE is in a disconnected state to the disconnection detection module 2. The first detection signal is a sinusoidal wave detection signal of a preset frequency. If the grounding wire PE is not disconnected, the voltage detection module 1 sends a second detection signal indicating that the grounding wire PE is not disconnected to the disconnection detection module 2. The second detection signal is a low-level detection signal.

[0024] Furthermore, the disconnection detection module 2 is used to detect whether the grounding wire PE is in a disconnected state. Specifically, when it receives a sinusoidal detection signal from the voltage detection module 1 indicating that the grounding wire PE is in a disconnected state, the disconnection detection module 2 outputs a disconnection pulse signal to the control module 3. The disconnection pulse signal is a PWM signal. At this time, the control module 3 can issue an alarm signal. When it receives a low-level detection signal from the voltage detection module 1 indicating that the grounding wire PE is not disconnected, the disconnection detection module 2 outputs a high-level signal to the control module 3. At this time, the control module 3 issues a normal signal. Then, when the control module 3 recognizes that the level signal output by the disconnection detection module 2 changes from a high-level signal to a disconnection pulse signal, it can issue an alarm signal. This allows for real-time detection of whether the grounding wire PE of the charging pile 4 is in a disconnected state, thereby improving the accuracy of the grounding wire PE disconnection detection. Moreover, no sampling resistor is connected in series in the voltage detection module 1, so the grounding wire disconnection detection device will not affect the impedance of the grounding wire loop. It also has strong anti-interference and strong compatibility, thus ensuring the safe operation of the charging pile 4.

[0025] In one alternative implementation, see [link to implementation details]. Figure 1 and Figure 2 The voltage detection module 1 includes a capacitor voltage divider unit 11 and a voltage detection unit 12; wherein, the first input terminal of the capacitor voltage divider unit 11 is connected to the neutral line N, the second input terminal of the capacitor voltage divider unit 11 is connected to the ground line PE, the first output terminal of the capacitor voltage divider unit 11 is connected to the first input terminal of the voltage detection unit 12, the second output terminal of the capacitor voltage divider unit 11 is connected to the second input terminal of the voltage detection unit 12, and the output terminal of the voltage detection unit 12 is connected to the disconnection detection module 2.

[0026] In this embodiment, the capacitor voltage divider unit 11 is used to perform the first voltage divider process on the voltage between the neutral wire N and the ground wire PE. The voltage detection unit 12 is used to detect the voltage between the neutral wire N and the ground wire PE in the charging pile 4, and to perform a second voltage divider process on the voltage after being divided by the capacitor voltage divider unit 11. This can effectively distinguish between the high voltage when the ground wire PE is in the disconnected state and the low voltage when the ground wire PE is in the active state, while also ensuring that the voltage in the back-end circuit is not too high, thus protecting the ground wire disconnection detection device.

[0027] It should be noted that no sampling resistor is connected in series in the capacitor voltage divider unit 11 and the voltage detection unit 12. Therefore, the grounding wire disconnection detection device will not affect the impedance of the grounding wire circuit, thereby ensuring the safe operation of the charging pile 4.

[0028] In one specific implementation, see [link to implementation details]. Figure 1 and Figure 2 The voltage detection unit 12 includes a voltage regulator subunit 121, a voltage detection subunit 122, and a resistor-capacitor voltage divider subunit 123. One end of the voltage regulator subunit 121 is connected to the first output terminal of the capacitor voltage divider unit 11, the other end of the voltage regulator subunit 121 is connected to the first end of the voltage detection subunit 122, the second end of the voltage detection subunit 122 is connected to the first input terminal of the resistor-capacitor voltage divider subunit 123, the second input terminal of the resistor-capacitor voltage divider subunit 123 is connected to the second output terminal of the capacitor voltage divider unit 11, and the output terminal of the resistor-capacitor voltage divider subunit 123 is connected to the input terminal of the disconnection detection module 2.

[0029] In this embodiment, the voltage regulator subunit 121 is used to smooth, filter noise, and provide local energy storage for the voltage after voltage division by the capacitor voltage divider unit 11, thereby stabilizing the operating voltage and preventing voltage surges from impacting the precision circuitry at the back end. The voltage detection subunit 122 is used to detect the voltage between the neutral line N and the ground line PE, so as to effectively distinguish between the high voltage when the ground line PE is disconnected and the low voltage when the ground line PE is not disconnected. The resistor-capacitor voltage divider subunit 123 is used to further divide the voltage after voltage division by the capacitor voltage divider unit 11 to ensure the stable operation of the circuit at the back end of the resistor-capacitor voltage divider subunit 123.

[0030] It should be noted that the capacitor voltage divider unit 11 uses only capacitors connected in series for voltage division, while the resistor-capacitor voltage divider subunit 123 uses both capacitors and resistors for voltage division.

[0031] In one specific implementation, see [link to implementation details]. Figure 2 The capacitor voltage divider unit 11 includes a first capacitor 111 and a second capacitor 112; wherein, one end of the first capacitor 111 is connected to the grounding wire PE, the other end of the first capacitor 111 is connected to the first end of the second capacitor 112, and the second end of the second capacitor 112 is connected to the neutral wire N and the voltage detection unit 12 respectively.

[0032] In one specific implementation, see [link to implementation details]. Figure 2 The voltage regulator subunit 121 includes a third capacitor 1211, the voltage detection subunit 122 includes a Zener diode 1221, and the resistor-capacitor voltage divider subunit 123 includes a fourth capacitor 1231, a fifth capacitor 1232, a sixth capacitor 1233, a first resistor 1234, a second resistor 1235, and a switching diode 1236. One end of the third capacitor 1211 is connected to the capacitor voltage divider subunit 11, and the other end of the third capacitor 1211 is connected to the cathode of the Zener diode 1221. The anode of the Zener diode 1221 is connected to the cathode of the fourth capacitor 1231. The fourth capacitor 1231 is connected to one end of the fifth capacitor 1232 and one end of the first resistor 1234. The other end of the first resistor 1234 is connected to one end of the sixth capacitor 1233, the first end of the switching diode 1236, one end of the second resistor 1235, and the switching subunit 211. The other ends of the fifth capacitor 1232, the sixth capacitor 1233, the second end of the switching diode 1236, the third end of the switching diode 1236, and the other end of the second resistor 1235 are all connected to the capacitor voltage divider unit 11.

[0033] In one specific embodiment, the first capacitor 111, the second capacitor 112, the third capacitor 1211, and the fourth capacitor 1231 are all nF-class safety capacitors. The first capacitor 111 and the second capacitor 112 are connected in series, so the voltage between the neutral line N and the ground line PE can be divided by the series-connected first capacitor 111 and the second capacitor 112. The third capacitor 1211 is used to filter and stabilize the voltage after voltage division by the capacitor voltage divider unit 11, which plays a role in protecting the circuit behind the third capacitor 1211. The Zener diode 1221 is used to detect the voltage between the neutral line N and the ground line PE, so as to effectively distinguish the high voltage when the ground line PE is in the off-line state and the low voltage when the ground line PE is in the on-line state.

[0034] Specifically, it mainly utilizes the characteristic that the impedance of Zener diode 1221 is very small when it is broken down and in the conducting state, and infinitely large when it is not broken down. When the grounding wire PE is in a disconnected state, the voltage between the neutral wire N and the grounding wire PE will increase significantly, exceeding the breakdown voltage of Zener diode 1221. At this time, there is current in the circuit of voltage detection module 1. Since the charging pile 4 has a 50Hz AC output, the voltage in the circuit is a 50Hz sine wave. Therefore, voltage detection module 1 sends a sine wave detection signal indicating that the grounding wire PE is in a disconnected state to disconnection detection module 2. When the grounding wire PE is not disconnected, the voltage between the neutral wire N and the grounding wire PE is very small, which cannot cause Zener diode 1221 to break down. At this time, Zener diode 1221 is in a high-impedance state, and there is no current in the circuit of voltage detection module 1. Therefore, voltage detection module 1 sends a low-level detection signal indicating that the grounding wire PE is not disconnected to disconnection detection module 2.

[0035] In one specific embodiment, the fourth capacitor 1231 is used to smooth the voltage in the circuit, the first resistor 1234 is the current-limiting resistor of the base of the transistor 2111 in the switching subunit 211, and the first resistor 1234, the fifth capacitor 1232 and the sixth capacitor 1233 form a π-type filter network to improve the voltage division and filtering effect of the RC voltage divider subunit 123 and ensure the stable operation of the circuit behind the RC voltage divider subunit 123. The switching diode 1236 provides a freewheeling path when the sine wave in the circuit is in the negative half-cycle, and the second resistor 1235 is the pull-down resistor of the transistor 2111.

[0036] In one alternative implementation, see [link to implementation details]. Figure 1 and Figure 2The disconnection detection module 2 includes a disconnection protection unit 21 and a disconnection detection unit 22; wherein, the input terminal of the disconnection protection unit 21 is connected to the output terminal of the voltage detection module 1, the output terminal of the disconnection protection unit 21 is connected to the control input terminal of the disconnection detection unit 22, the power supply input terminal of the disconnection detection unit 22 is connected to the power supply VCC, and the output terminal of the disconnection detection unit 22 is connected to the control module 3.

[0037] In this embodiment, the disconnection protection unit 21 is used to receive a sinusoidal detection signal indicating that the grounding wire PE is in a disconnected state and a low-level detection signal indicating that the grounding wire PE is not disconnected, sent by the voltage detection module 1. When the sinusoidal detection signal is received, the unit alternates between on and off states, and when the low-level detection signal is received, the unit is in an off state to provide power-off protection for subsequent circuits. The disconnection detection unit 22 is used to detect whether the grounding wire PE is in a disconnected state. Specifically, when the grounding wire PE is in a disconnected state, the disconnection detection unit 22 generates a disconnection pulse signal and outputs it to the control module 3. When the grounding wire PE is not disconnected, the disconnection detection unit 22 generates a high-level signal and outputs it to the control module 3. This allows for real-time detection of whether the grounding wire PE of the charging pile 4 is in a disconnected state, improving the accuracy of grounding wire PE disconnection detection, and providing strong anti-interference and compatibility, thereby ensuring the safe operation of the charging pile 4.

[0038] In one specific implementation, see [link to implementation details]. Figure 1 and Figure 2 The disconnection protection unit 21 includes a switch subunit 211, a voltage clamping subunit 212, and a discharge subunit 213. The first end of the switch subunit 211 is connected to the output end of the voltage detection module 1. The second end of the switch subunit 211 is connected to the first end of the voltage clamping subunit 212 and the first end of the discharge subunit 213. The third end of the switch subunit 211, the second end of the voltage clamping subunit 212, and the second end of the discharge subunit 213 are all grounded. The third end of the discharge subunit 213 is connected to the control input end of the disconnection detection unit 22.

[0039] Specifically, the switching subunit 211 is used to receive the sinusoidal detection signal indicating that the grounding wire PE is in a disconnected state and the low-level detection signal indicating that the grounding wire PE is not disconnected, sent by the voltage detection module 1. When the sinusoidal detection signal is received, it is in an alternating on and off state, and when the low-level detection signal is received, it is in an off state. The voltage clamping subunit 212 is used to clamp the voltage so that the voltage is at a relatively safe voltage. The relatively safe voltage can be set according to the actual situation. The discharge subunit 213 is used to quickly guide the residual charge in the capacitor to the ground or dissipate it, thereby ensuring the safety of the grounding wire disconnection detection device and ensuring the stable and reliable operation of the system. At the same time, it is also used to provide a part of the filtering function for the signal to the pin of the optocoupler 225.

[0040] In one specific implementation, see [link to implementation details]. Figure 2 The switching subunit 211 includes a transistor 2111, the voltage clamping subunit 212 includes a bidirectional transient voltage suppressor diode 2121, and the discharge subunit 213 includes a seventh capacitor 2131, an eighth capacitor 2132, and a third resistor 2133. The base of the transistor 2111 is connected to the voltage detection module 1. The collector of the transistor 2111 is connected to one end of the bidirectional transient voltage suppressor diode 2121, one end of the seventh capacitor 2131, one end of the eighth capacitor 2132, one end of the third resistor 2133, and the control input terminal of the disconnection detection unit 22. The emitter of the transistor 2111, the other end of the bidirectional transient voltage suppressor diode 2121, the other end of the seventh capacitor 2131, the other end of the eighth capacitor 2132, and the other end of the third resistor 2133 are all grounded. One end of the third resistor 2133 is also connected to the control input terminal of the disconnection detection unit 22.

[0041] Specifically, the base of transistor 2111 is connected to Zener diode 1221 through first resistor 1234 and fourth capacitor 1231. Thus, when the grounding wire PE is de-energized, Zener diode 1221 is in a breakdown and conducting state. The base of transistor 2111 receives a sine wave detection signal and is in an alternating state of conduction and disconnection. That is, when the sine wave detection signal is in the positive half-cycle, transistor 2111 is in the conducting state, and when the sine wave detection signal is in the negative half-cycle, transistor 2111 is in the disconnected state. Furthermore, when the grounding wire PE is not de-energized, Zener diode 1221 is not in a breakdown state, and the base of transistor 2111 receives a low-level detection signal and is in the disconnected state.

[0042] In one specific embodiment, the bidirectional transient voltage suppression diode 2121 is used to clamp the voltage so that the voltage is at a relatively safe level. The seventh capacitor 2131, the eighth capacitor 2132, and the third resistor 2133 constitute a bleeder circuit. Furthermore, since the bleeder circuit composed of the seventh capacitor 2131, the eighth capacitor 2132, and the third resistor 2133 is also connected to the input terminal of the optocoupler 225, the bleeder circuit provides a partial filtering function for the signal to the pin of the optocoupler 225.

[0043] In one specific implementation, see [link to implementation details]. Figure 2 The disconnection detection unit 22 includes a first current-limiting resistor 221, a second current-limiting resistor 222, a pull-up resistor 223, a π-type filter circuit 224, and an optocoupler 225. One end of the first current-limiting resistor 221 is connected to the output terminal of the disconnection protection unit 21, and the other end of the first current-limiting resistor 221 is connected to the first input terminal of the optocoupler 225. The second input terminal of the optocoupler 225 is connected to the power supply VCC through the second current-limiting resistor 222. The first output terminal of the optocoupler 225 is connected to one end of the pull-up resistor 223 and the π-type filter circuit 224, respectively. The second output terminal of the optocoupler 225 is grounded. The π-type filter circuit 224 is also connected to the control module 3.

[0044] Furthermore, in one specific embodiment, the π-type filter circuit 224 includes a ninth capacitor 2241, a tenth capacitor 2242, and a fourth resistor 2243; wherein, the first output terminal of the optocoupler 225 is connected to one end of the ninth capacitor 2241 and one end of the fourth resistor 2243, respectively, and the second output terminal of the optocoupler 225 is also connected to the other end of the ninth capacitor 2241 and one end of the tenth capacitor 2242, respectively, and the other end of the tenth capacitor 2242 is connected to the other end of the ninth capacitor 2241, and the ninth capacitor 2241 and the tenth capacitor 2242 are connected in parallel.

[0045] Specifically, since the first input terminal of optocoupler 225 is connected to the collector of transistor 2111 through the first current-limiting resistor 221, and the second input terminal of optocoupler 225 is connected to the power supply VCC through the second current-limiting resistor 222, when transistor 2111 is in an open state because the grounding wire PE is not de-energized, the first input terminal of optocoupler 225 is in an ungrounded state. At this time, the light-emitting diode on the primary side of optocoupler 225 is not working, and the two output terminals on the secondary side of optocoupler 225 are in a cut-off state. Since the first output terminal of optocoupler 225 is connected to the regulated power supply VD3V3 through pull-up resistor 223, the output of optocoupler 225 is a high-level signal pulled up by pull-up resistor 223. Furthermore, when transistor 2111 alternates between on and off states due to the ground wire PE being de-energized, the light-emitting diode on the primary side of optocoupler 225 also alternates between on and off states. Consequently, the photodiode on the secondary side of optocoupler 225 also alternates between on and off states, thus optocoupler 225 outputs a disconnection pulse signal to control module 3. See also... Figure 2 The circuit includes multiple ground pins (GND) to provide zero potential.

[0046] In one specific embodiment, when the control module 3 receives a high-level signal output by the optocoupler 225 because the grounding wire PE is in a non-power-off state, it issues a normal signal. When the control module 3 receives a disconnection pulse signal output by the optocoupler 225 because the grounding wire PE is in a power-off state, it issues an alarm signal. This enables real-time detection of whether the grounding wire PE of the charging pile 4 is in a disconnection state, thereby improving the accuracy of grounding wire PE disconnection detection. It also has strong anti-interference and strong compatibility, thus ensuring the safe operation of the charging pile 4.

[0047] The following combination Figure 1 and Figure 2 This application introduces a specific embodiment of a grounding wire disconnection detection device.

[0048] The grounding wire disconnection detection device includes a voltage detection module 1, a disconnection detection module 2, and a control module 3. The voltage detection module 1 includes a capacitor voltage divider unit 11, a voltage regulator subunit 121, a voltage detection subunit 122, and a resistor-capacitor voltage divider subunit 123. The capacitor voltage divider unit 11 includes a first capacitor 111 and a second capacitor 112. The voltage regulator subunit 121 includes a third capacitor 1211. The voltage detection subunit 122 includes a Zener diode 1221. The resistor-capacitor voltage divider unit 123 includes a fourth capacitor 1231, a fifth capacitor 1232, a sixth capacitor 1233, a first resistor 1234, a second resistor 1235, and an open circuit. The diode 1236 is turned off. The disconnection detection module 2 includes a switch subunit 211, a voltage clamping subunit 212, a discharge subunit 213, a first current limiting resistor 221, a second current limiting resistor 222, a pull-up resistor 223, a π-type filter circuit 224, and an optocoupler 225. The switch subunit 211 includes a transistor 2111. The voltage clamping subunit 212 includes a bidirectional transient voltage suppression diode 2121. The discharge subunit 213 includes a seventh capacitor 2131, an eighth capacitor 2132, and a third resistor 2133. The π-type filter circuit 224 includes a ninth capacitor 2241, a tenth capacitor 2242, and a fourth resistor 2243.

[0049] The circuit structure of the above-mentioned device is as follows: one end of the first capacitor 111 is connected to the ground line PE, the other end of the first capacitor 111 is connected to the first end of the second capacitor 112, the second end of the second capacitor 112 is connected to the neutral line N and one end of the third capacitor 1211, the other end of the third capacitor 1211 is connected to the negative terminal of the Zener diode 1221, the positive terminal of the Zener diode 1221 is connected to one end of the fourth capacitor 1231, the other end of the fourth capacitor 1231 is connected to one end of the fifth capacitor 1232 and one end of the first resistor 1234, the other end of the first resistor 1234 is connected to one end of the sixth capacitor 1233, the first end of the switching diode 1236, one end of the second resistor 1235 and the base of the transistor 2111, the other end of the fifth capacitor 1232, the other end of the sixth capacitor 1233, the second end of the switching diode 1236, the third end of the switching diode 1236 and the other end of the second resistor 1235 are all connected to the other end of the first capacitor 111.

[0050] Furthermore, the collector of transistor 2111 is connected to one end of bidirectional transient voltage suppressor diode 2121, one end of seventh capacitor 2131, one end of eighth capacitor 2132, one end of third resistor 2133, and one end of first current-limiting resistor 221, respectively. The emitter of transistor 2111, the other end of bidirectional transient voltage suppressor diode 2121, the other end of seventh capacitor 2131, the other end of eighth capacitor 2132, and the other end of third resistor 2133 are all grounded. One end of third resistor 2133 is also connected to one end of first current-limiting resistor 221, and the other end of first current-limiting resistor 221 is connected to the first input of optocoupler 225. The second input terminal of the optocoupler 225 is connected to the power supply VCC through the second current limiting resistor 222. The first output terminal of the optocoupler 225 is connected to one end of the pull-up resistor 223, one end of the fourth resistor 2243, and one end of the ninth capacitor 2241. The second output terminal of the optocoupler 225 is grounded. The second output terminal of the optocoupler 225 is also connected to the other end of the ninth capacitor 2241 and one end of the tenth capacitor 2242. The other end of the tenth capacitor 2242 is connected to the other end of the ninth capacitor 2241. The ninth capacitor 2241 and the tenth capacitor 2242 are connected in parallel. The other end of the fourth resistor 2243 is also connected to the control module 3.

[0051] Based on the above circuit structure, when the grounding wire PE is not disconnected, the voltage between the neutral wire N and the grounding wire PE is very small, which cannot cause the Zener diode 1221 to break down. At this time, the Zener diode 1221 is in a high-impedance state, and the base of the transistor 2111 is affected by the second pull-down resistor 1235 and receives a low-level detection signal. At this time, the transistor 2111 is in an open state. Since the base of the transistor 2111 is connected to the first input terminal of the optocoupler 225 through the first current-limiting resistor 221, the first input terminal of the optocoupler 225 is in an ungrounded state, and the light-emitting diode on the primary side of the optocoupler 225 is in a non-working state. Therefore, the two output terminals on the secondary side of the optocoupler 225 are in a cut-off state. At the same time, since the first output terminal of the optocoupler 225 is connected to the regulated power supply VD3V3 through the pull-up resistor 223, the optocoupler 225 outputs a high-level signal pulled up by the pull-up resistor 223 to the control module 3.

[0052] Furthermore, when the grounding wire PE is in a de-energized state, the voltage between the neutral wire N and the grounding wire PE will increase significantly, exceeding the breakdown voltage of the Zener diode 1221. The Zener diode 1221 will be in a breakdown and conducting state. At this time, the voltage in the circuit is a 50Hz sine wave detection signal, and the transistor 2111 will be in an alternating state of conduction and disconnection. When the sine wave detection signal is in the positive half-cycle, the transistor 2111 is in the conducting state, and when the sine wave detection signal is in the negative half-cycle, the transistor 2111 is in the disconnected state. When the transistor 2111 is in an alternating state of conduction and disconnection due to the grounding wire PE being de-energized, the light-emitting diode on the primary side of the optocoupler 225 is in an alternating state of conduction and disconnection, and the photodiode on the secondary side of the optocoupler 225 is also in an alternating state of conduction and disconnection. As a result, the optocoupler 225 outputs a de-energized pulse signal to the control module 3.

[0053] Furthermore, when the control module 3 detects that the level signal output by the optocoupler 225 changes from a high level signal to a disconnection pulse signal, it can issue an alarm signal, thereby enabling real-time detection of whether the grounding wire PE of the charging pile 4 is in a disconnection state, thus improving the accuracy of grounding wire PE disconnection detection.

[0054] As can be seen from the above technical solutions of the embodiments of this application, the following technical effects are achieved: This application incorporates a voltage detection module, a grounding wire disconnection detection module, and a control module. The grounding wire disconnection detection module, responding to a first detection signal from the voltage detection module indicating a disconnected grounding wire, outputs a disconnection pulse signal to the control module. Conversely, the grounding wire disconnection detection module, responding to a second detection signal from the voltage detection module indicating a non-disconnected grounding wire, outputs a high-level signal to the control module. When the control module detects a change in the signal level from high to a disconnection pulse signal, it issues an alarm signal. This allows for real-time detection of grounding wire disconnection, improving the accuracy of grounding wire disconnection detection. Furthermore, it exhibits strong anti-interference capabilities, high compatibility, and does not affect the impedance of the grounding wire loop, thus ensuring the safe operation of the charging pile.

[0055] The structure shown in this embodiment is only a partial structure related to the solution of this application and does not constitute a limitation on the device to which the solution of this application is applied. Specific devices may include more or fewer components than shown, or combinations of certain components, or arrangements of different components. It should be understood that the methods, apparatuses, etc., disclosed in this embodiment can be implemented in other ways.

[0056] The above description is merely a specific embodiment of this application, but the scope of protection of this application 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 this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A grounding wire disconnection detection device, characterized in that, It includes a voltage detection module (1), a disconnection detection module (2), and a control module (3); The first input terminal of the voltage detection module (1) is used to connect to the neutral wire of the charging pile (4), the second input terminal of the voltage detection module (1) is connected to the ground wire of the charging pile (4), the output terminal of the voltage detection module (1) is connected to the control input terminal of the disconnection detection module (2), the power supply input terminal of the disconnection detection module (2) is used to connect to the power supply, and the output terminal of the disconnection detection module (2) is connected to the control module (3). The disconnection detection module (2) is used to output a disconnection pulse signal to the control module (3) in response to a first detection signal output by the voltage detection module (1) indicating that the grounding wire is in a disconnection state. The disconnection detection module (2) is also used to output a high-level signal to the control module (3) in response to a second detection signal output by the voltage detection module (1) indicating that the grounding wire is in a non-disconnection state.

2. The grounding wire disconnection detection device according to claim 1, characterized in that, The voltage detection module (1) includes a capacitor voltage divider unit (11) and a voltage detection unit (12); The first input terminal of the capacitor voltage divider unit (11) is connected to the neutral line, the second input terminal of the capacitor voltage divider unit (11) is connected to the ground line, the first output terminal of the capacitor voltage divider unit (11) is connected to the first input terminal of the voltage detection unit (12), the second output terminal of the capacitor voltage divider unit (11) is connected to the second input terminal of the voltage detection unit (12), and the output terminal of the voltage detection unit (12) is connected to the disconnection detection module (2).

3. The grounding wire disconnection detection device according to claim 2, characterized in that, The voltage detection unit (12) includes a voltage regulator subunit (121), a voltage detection subunit (122), and a resistor-capacitor voltage divider subunit (123); One end of the voltage regulator subunit (121) is connected to the first output terminal of the capacitor voltage divider unit (11), the other end of the voltage regulator subunit (121) is connected to the first terminal of the voltage detection subunit (122), the second terminal of the voltage detection subunit (122) is connected to the first input terminal of the resistor-capacitor voltage divider unit (123), the second input terminal of the resistor-capacitor voltage divider unit (123) is connected to the second output terminal of the capacitor voltage divider unit (11), and the output terminal of the resistor-capacitor voltage divider unit (123) is connected to the input terminal of the disconnection detection module (2).

4. The grounding wire disconnection detection device according to claim 1, characterized in that, The disconnection detection module (2) includes a disconnection protection unit (21) and a disconnection detection unit (22); The input terminal of the disconnection protection unit (21) is connected to the output terminal of the voltage detection module (1), the output terminal of the disconnection protection unit (21) is connected to the control input terminal of the disconnection detection unit (22), the power supply input terminal of the disconnection detection unit (22) is connected to the power supply, and the output terminal of the disconnection detection unit (22) is connected to the control module (3).

5. The grounding wire disconnection detection device according to claim 4, characterized in that, The disconnection protection unit (21) includes a switching subunit (211), a voltage clamping subunit (212), and a discharge subunit (213); The first end of the switching subunit (211) is connected to the output end of the voltage detection module (1). The second end of the switching subunit (211) is connected to the first end of the voltage clamping subunit (212) and the first end of the discharge subunit (213). The third end of the switching subunit (211), the second end of the voltage clamping subunit (212), and the second end of the discharge subunit (213) are all grounded. The third end of the discharge subunit (213) is connected to the control input end of the disconnection detection unit (22).

6. The grounding wire disconnection detection device according to claim 4, characterized in that, The disconnection detection unit (22) includes a first current-limiting resistor (221), a second current-limiting resistor (222), a pull-up resistor (223), a π-type filter circuit (224), and an optocoupler (225); One end of the first current-limiting resistor (221) is connected to the output terminal of the disconnection protection unit (21), and the other end of the first current-limiting resistor (221) is connected to the first input terminal of the optocoupler (225). The second input terminal of the optocoupler (225) is connected to the power supply through the second current-limiting resistor (222). The first output terminal of the optocoupler (225) is connected to one end of the pull-up resistor (223) and the π-type filter circuit (224) respectively. The second output terminal of the optocoupler (225) is grounded. The π-type filter circuit (224) is also connected to the control module (3).

7. The grounding wire disconnection detection device according to claim 2, characterized in that, The capacitor voltage divider unit (11) includes a first capacitor (111) and a second capacitor (112); One end of the first capacitor (111) is connected to the grounding wire, and the other end of the first capacitor (111) is connected to the first end of the second capacitor (112). The second end of the second capacitor (112) is connected to the neutral wire and the voltage detection unit (12) respectively.

8. The grounding wire disconnection detection device according to claim 3, characterized in that, The voltage regulator subunit (121) includes a third capacitor (1211), the voltage detection subunit (122) includes a Zener diode (1221), and the resistor-capacitor voltage divider subunit (123) includes a fourth capacitor (1231), a fifth capacitor (1232), a sixth capacitor (1233), a first resistor (1234), a second resistor (1235), and a switching diode (1236). One end of the third capacitor (1211) is connected to the capacitor voltage divider unit (11), and the other end of the third capacitor (1211) is connected to the negative terminal of the Zener diode (1221). The positive terminal of the Zener diode (1221) is connected to one end of the fourth capacitor (1231). The other end of the fourth capacitor (1231) is connected to one end of the fifth capacitor (1232) and one end of the first resistor (1234). The other end of the first resistor (1234) is connected to one end of the sixth capacitor (1233), the first end of the switching diode (1236), one end of the second resistor (1235), and the switching subunit (211). The other end of the fifth capacitor (1232), the other end of the sixth capacitor (1233), the second end of the switching diode (1236), the third end of the switching diode (1236), and the other end of the second resistor (1235) are all connected to the capacitor voltage divider unit (11).

9. The grounding wire disconnection detection device according to claim 5, characterized in that, The switching subunit (211) includes a transistor (2111), the voltage clamping subunit (212) includes a bidirectional transient voltage suppressor diode (2121), and the discharge subunit (213) includes a seventh capacitor (2131), an eighth capacitor (2132), and a third resistor (2133). The base of the transistor (2111) is connected to the voltage detection module (1). The collector of the transistor (2111) is connected to one end of the bidirectional transient voltage suppressor diode (2121), one end of the seventh capacitor (2131), one end of the eighth capacitor (2132), one end of the third resistor (2133), and the control input terminal of the disconnection detection unit (22). The emitter of the transistor (2111), the other end of the bidirectional transient voltage suppressor diode (2121), the other end of the seventh capacitor (2131), the other end of the eighth capacitor (2132), and the other end of the third resistor (2133) are all grounded. One end of the third resistor (2133) is also connected to the control input terminal of the disconnection detection unit (22).

10. The grounding wire disconnection detection device according to claim 6, characterized in that, The π-type filter circuit (224) includes a ninth capacitor (2241), a tenth capacitor (2242), and a fourth resistor (2243); The first output terminal of the optocoupler (225) is connected to one end of the ninth capacitor (2241) and one end of the fourth resistor (2243), respectively. The second output terminal of the optocoupler (225) is also connected to the other end of the ninth capacitor (2241) and one end of the tenth capacitor (2242), respectively. The other end of the tenth capacitor (2242) is connected to the other end of the ninth capacitor (2241). The ninth capacitor (2241) and the tenth capacitor (2242) are connected in parallel.

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