Detection circuit, three-phase detection circuit and charging pile

Abstract

The utility model discloses a detection circuit, a three-phase detection circuit and a charging pile, and relates to the technical field of circuit fault detection. The detection circuit comprises a relay module, a switch control module and a detection module, the relay module comprises a control unit and a first switch unit, the first end of the first switch unit is connected with the output end of an L-phase line, the control unit is used for transmitting a first control signal, and the first switch unit is used for responding to the first control signal to be switched on; the switch control module is connected with the two ends of the control unit and used for responding to the driving signal to conduct a power supply access to the control unit; the detection module is connected with the second end of the first switch unit, the detection module is used for limiting the input signal, the detection module is provided with a detection node, and the voltage of the detection node is changed when the detection module receives the electric signal input by the L phase line. The detection circuit provided by the utility model can be used for relay adhesion detection and line short circuit detection.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of circuit fault detection, in particular to a detection circuit, a three-phase detection circuit and a charging pile. BACKGROUND

[0002] An alternating current charging pile is a key equipment for supplementing energy of an electric vehicle and a hybrid vehicle. A relay is arranged in the alternating current charging pile. The relay controls a high-voltage circuit through low-voltage. High performance and high reliability of the relay are key to stable operation of the charging pile system.

[0003] However, due to the characteristics of the relay, in a large-current application scenario, the relay may not be normally disconnected. This is called relay sticking, which may cause safety hazards to the equipment. In addition, an output end line may be short-circuited, which may also cause safety hazards to the equipment. Therefore, it is necessary to detect the sticking of the relay and the short circuit of the output end line.

[0004] GB 44263-2024 Safety Requirements for Electric Vehicle Conductive Charging Systems stipulates that the charging pile equipment needs to be detected for sticking and short circuit. CONTENT OF THE INVENTION

[0005] The main purpose of the application is to provide a detection circuit, a three-phase detection circuit and a charging pile, which are used for detecting the sticking of the relay and the short circuit of the output end line.

[0006] To achieve the above purpose, in a first aspect, the application provides a detection circuit, which comprises:

[0007] A relay module comprising a control unit and a first switching unit, a first end of the first switching unit being connected with an output end of an L-phase line, the control unit being used for emitting a first control signal, and the first switching unit being used for conducting in response to the first control signal;

[0008] A switching control module connected with two ends of the control unit respectively, the switching control module being used for conducting the power supply path of the control unit in response to a driving signal, so that the control unit emits the first control signal;

[0009] A detection module connected with a second end of the first switching unit, the detection module being used for limiting processing of an input signal, wherein the detection module has a detection node, and a voltage of the detection node changes when the detection module receives an electrical signal input by the L-phase line, which indicates that there is relay sticking or LN-phase short circuit;

[0010] Wherein, when the L-phase relay is disconnected, the electrical signal of the detection node jumps from the first level to the second level, and the L-phase relay is stuck; when the L-phase relay is disconnected and the N-phase relay is closed, the electrical signal of the detection node jumps from the first level to the second level, and the L N-phase is short-circuited.

[0011] In an embodiment, the control unit comprises a first light-emitting device, and the first switch unit comprises a photosensitive switch.

[0012] The two ends of the first light-emitting device are connected with the switch control module respectively.

[0013] The first end of the photosensitive switch is connected with the output end of the L-phase line, and the second end of the photosensitive switch is connected with the detection module.

[0014] In an embodiment, the photosensitive switch comprises a photovoltaic diode and a field effect tube, the photovoltaic diode is connected with the gate of the field effect tube, the first pole of the field effect tube is connected with the output end of the L-phase line, and the second pole of the field effect tube is connected with the detection module.

[0015] In an embodiment, the control unit comprises an electromagnet, and the first switch unit comprises a contact switch.

[0016] The two ends of the electromagnet are connected with the switch control module respectively, for generating electromagnetic force to attract the moving contact of the contact switch when receiving the power supply of the switch control module, so as to make the contact switch conductive.

[0017] The first end of the contact switch is connected with the output end of the L-phase line, and the second end of the contact switch is connected with the detection module.

[0018] In an embodiment, the switch control module comprises:

[0019] A first current limiting unit is used for receiving a first power signal and is connected with the two ends of the control unit respectively.

[0020] A second switch unit, the first end of the second switch unit is connected with the first current limiting unit, and the second end of the second switch unit is connected with a common ground, and the second switch unit is used for connecting the first current limiting unit and the common ground in response to the driving signal.

[0021] In an embodiment, the first current limiting unit comprises:

[0022] A first current limiting resistor, the first end of the first current limiting resistor is used for receiving a first power signal.

[0023] A protection diode, a negative electrode of the protection diode is connected with the second end of the first current-limiting resistor and the first end of the control unit, and a positive electrode of the protection diode is connected with the second end of the control unit and the first end of the second switch unit respectively.

[0024] In an embodiment, the detection module comprises:

[0025] A second current-limiting unit, the second current-limiting unit is connected with the second end of the first switch unit;

[0026] An optical coupling isolation unit, comprising a second light-emitting device and a light-sensitive device, two ends of the second light-emitting device are connected with the second current-limiting unit respectively;

[0027] A first detection unit, for receiving a second power supply signal, and connected with two ends of the light-sensitive device and a common ground terminal respectively, a detection node of the first detection unit is used as a detection node of the detection module, and a voltage of the detection node changes when the light-sensitive device is turned on.

[0028] In an embodiment, the first detection unit comprises:

[0029] A first voltage dividing resistor, the first voltage dividing resistor is used for receiving the second power supply signal;

[0030] A first voltage stabilizing capacitor, a first end of the first voltage stabilizing capacitor is connected with a second end of the first voltage dividing resistor and a first end of the light-sensitive device respectively, and is used as the detection node;

[0031] A first grounding resistor, a first end of the first grounding resistor is connected with a second end of the light-sensitive device and a second end of the voltage stabilizing capacitor respectively, and a second end of the first grounding resistor is connected with the common ground terminal.

[0032] In an embodiment, the detection module comprises:

[0033] A third current-limiting unit, a first end of the third current-limiting unit is connected with the second end of the first switch unit;

[0034] A second detection unit, the second detection unit is used for receiving a second power supply signal, and connected with a second end of the third current-limiting unit and a common ground terminal respectively, a detection node of the second detection unit is used as a detection node of the detection module, and a voltage of the detection node changes when the second detection unit receives an electrical signal input by the L-phase line.

[0035] In an embodiment, the third current-limiting unit comprises:

[0036] at least one second current-limiting resistor, each of the second current-limiting resistor being arranged in series between the second end of the first switch unit and the detection node;

[0037] a second ground resistor, a first end of the second ground resistor being connected with the detection node, and a second end of the second ground resistor being connected with the common ground end.

[0038] In an embodiment, the second detection unit comprises:

[0039] a second voltage-dividing resistor, the second voltage-dividing resistor being configured to receive the second power supply signal;

[0040] a second voltage-stabilizing capacitor, a first end of the second voltage-stabilizing capacitor being connected with a second end of the second voltage-dividing resistor and a second end of the third current-limiting unit respectively, and the first end of the second voltage-stabilizing capacitor being configured as the detection node, and a second end of the second voltage-stabilizing capacitor being connected with the common ground end.

[0041] In a second aspect, the present application provides a three-phase detection circuit, the three-phase detection circuit comprising: three detection circuits as described in the first aspect, and the three detection circuits being respectively connected with output ends of three L-phase lines in a three-phase alternating current circuit.

[0042] In a third aspect, the present application further provides a charging pile, the charging pile comprising: a master control chip and a detection circuit as described in the first aspect, the master control chip being connected with the detection circuit, and the master control chip being configured to output the driving signal and receive a voltage signal of the detection node.

[0043] In an embodiment, the charging pile further comprises: a prompting unit, the prompting unit being electrically connected with the master control chip, and the prompting unit being configured to send a prompt information.

[0044] The detection circuit and the charging pile include a relay module, a switch control module and a detection module. The relay module includes a control unit and a first switch unit. A first end of the first switch unit is connected with an output end of an L-phase line, and a second end of the first switch unit is connected with the detection module. After the switch control module is turned on in response to a driving signal to turn on a power supply path of the control unit, the control unit transmits a first control signal to the first switch unit. The first switch unit is turned on in response to the first control signal, and the L-phase line is turned on with the detection module. Since the voltage of a detection node in the detection module changes when the detection module receives an electrical signal input by the L-phase line, whether the L-phase line transmits a voltage signal to the detection module can be determined by detecting whether the voltage of the detection node changes. Based on this, when the relay corresponding to the L-phase line is in an open state, the driving signal is output to the switch control module. If the voltage of the detection node changes, it is determined that the relay corresponding to the L-phase line is stuck, thereby realizing the relay sticking detection of the relay on the L-phase line. When the relay corresponding to the L-phase line is in an open state and the relay on the N-phase line is turned on, the driving signal is output to the switch control module. If the voltage of the detection node changes, it is determined that the output end of the L-phase line is short-circuited with the N-phase line, thereby realizing the short-circuit detection between the L-phase line and the N-phase line.

[0045] The three-phase detection circuit includes three detection circuits described above. The three detection circuits are respectively connected with the output ends of three L-phase lines in a three-phase alternating current line. The relay sticking detection of the relays on the three L-phase lines and the short-circuit detection between the three L-phase lines and the N-phase line can be realized by the three detection circuits. When the relays on the three L-phase lines are not stuck, the relays on part of the L-phase lines are closed, and the relays on part of the L-phase lines are opened. Based on the on-off states of the relays and the voltage of the detection node, the short-circuit detection between the L-phase lines can be realized, thereby realizing the relay sticking detection and the short-circuit detection between the lines by one type of detection circuit, without using different types of detection circuits for the relay sticking detection and the short-circuit detection between the lines. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the drawings shown.

[0047] Figure 1 It is a structural schematic diagram of the detection circuit in an embodiment of the present application.

[0048] Figure 2Fig. 1 is a schematic diagram of the association structure of the L-phase line and the L-phase relay in an embodiment of the present application;

[0049] Figure 3 Fig. 2 is a schematic diagram of the association structure of the N-phase line and the N-phase relay in an embodiment of the present application;

[0050] Figure 4 Fig. 3 is a schematic diagram of the structure of the detection circuit in another embodiment of the present application;

[0051] Figure 5 Fig. 4 is a schematic diagram of the structure of the detection circuit in still another embodiment of the present application;

[0052] Figure 6 Fig. 5 is a schematic diagram of the structure of the detection circuit in yet another embodiment of the present application;

[0053] Figure 7 Fig. 6 is a schematic diagram of the structure of the detection circuit in still another embodiment of the present application;

[0054] Figure 8 Fig. 7 is a structural block diagram of the charging pile in yet another embodiment of the present application.

[0055] Brief Description of the Drawings

[0056] 11 - relay module, 111 - control unit, 1111 - first light emitting device, 1112 - electromagnet, 112 - first switch unit, 1121 - photosensitive switch, 1122 - contact switch, 12 - switch control module, 121 - first current limiting unit, R01 - first current limiting resistor, D1 - protection diode, 122 - second switch unit, Q1 - triode, R1 - first resistor, R2 - second resistor, 13 - detection module, 131 - second current limiting unit, R3 - third resistor, R4 - fourth resistor, 132 - optical coupling isolation unit, 1321 - second light emitting device, 1322 - photosensitive device, 133 - first detection unit, R11 - first voltage dividing resistor, C1 - first voltage stabilizing capacitor, R21 - first grounding resistor, 134 - third current limiting unit, R02 - second current limiting resistor, R22 - second grounding resistor, 135 - second detection unit, R12 - second voltage dividing resistor, C2 - second voltage stabilizing capacitor, 14 - current limiting unit, 141 - current limiting resistor, 15 - main control chip, S1 - L-phase relay, S2 - N-phase relay, M1 - detection node.

[0057] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0058] With reference to the drawings and the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0059] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0060] In addition, if the embodiments of the present application involve descriptions such as “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is also not within the scope of protection claimed by the present application.

[0061] As described in the background, the alternating current charging pile is a key equipment for electric vehicles and hybrid vehicles to supplement energy. A relay is arranged in the alternating current charging pile, the relay controls a high-voltage circuit through a low-voltage, and high performance and high reliability of the relay are the key to ensure stable operation of the charging pile system.

[0062] During the charging process, there may be a situation of relay sticking, which will cause the charging pile to be unable to normally switch the working state, such as being unable to normally start or stop the charging process, thereby affecting the overall performance and reliability of the charging pile. The sticking relay may cause equipment damage due to overheating or other electrical problems, shorten the service life of the charging pile, and even cause electrical faults such as short circuit or overload, posing a safety threat to users using the charging pile. L-phase (fire wire) sticking may cause the charging pile to be live in a situation where it should not be live, increasing the risk of contact and the possibility of equipment damage. During the charging process, there may also be a situation of LN-phase line (fire wire and zero wire) short circuit, which will cause a large current to flow in the circuit and generate a large amount of heat. In an ideal state, the circuit breaker will automatically open the circuit to ensure the safety of the circuit. However, if the circuit breaker fails, the consequences will be quite serious, which may cause a fire. In addition, short circuit may also cause the charging pile and the electrical equipment connected thereto to be burned and damaged, posing a great safety risk to the user. Therefore, it is necessary to detect the sticking of the relay and the short circuit of the output line.

[0063] To solve the above problems, the embodiment of the present application provides a detection circuit, as shown in the figure, which comprises a relay module 11, a switch control module 12 and a detection module 13. Figure 1 Figure 1 In the figure, the L1 end is connected to the output end of the corresponding L-phase line.

[0064] The relay module 11 comprises a control unit 111 and a first switch unit 112, the first end of the first switch unit 112 is connected to the output end of the L-phase line, and the control unit 111 is used to emit a first control signal, and the first switch unit 112 is used to conduct in response to the first control signal.

[0065] Wherein, the first control signal is emitted by the control unit 111 to control the first switch unit 112 to conduct, and the on-off of the large power circuit can be controlled by a small current. In this way, a low-voltage and small-current control signal can be used to indirectly control a high-voltage and large-current circuit, avoiding the danger and inconvenience caused by directly operating a large current.

[0066] The switch control module 12 is connected to both ends of the control unit 111 respectively, and the switch control module 12 is used to conduct the power supply path to the control unit 111 in response to the driving signal Vd, so that the control unit 111 emits the first control signal.

[0067] ​The first end of the first switching unit 112 can be connected with the output end of the L-phase line through the current limiting unit 14, and the current limiting unit 14 can be a current limiting resistor 141. The reliability of the detection circuit is ensured by setting the current limiting unit 14. The driving signal Vd can be output by the master control chip 15. The master control chip 15 can control the output driving signal Vd to the switching control module 12, control the power supply path of the control unit 111 to be turned on, make the control unit 111 emit the first control signal, and then make the first switching unit 112 turn on in response to the first control signal. Therefore, the master control chip 15 can control the turn-on of the first switching unit 112 through the switching control module 12.

[0068] It should be noted that the control unit 111 and the first switching unit 112 are electrically isolated, which means that there is no direct electrical connection between the switching control module 12 and the high-power circuit where the first switching unit 112 is located. This isolation can effectively prevent high voltage and large current in the high-power circuit from interfering with and damaging the switching control module 12, thereby improving the stability and reliability of the entire system.

[0069] The detection module 13 is connected with the second end of the first switching unit 112, and the detection module 13 is used for limiting processing of the input signal to protect the subsequent circuit. The detection module 13 has a detection node, and the voltage of the detection node changes when the detection module 13 receives the L-phase line input electrical signal. The change in the voltage of the detection node indicates that there is a relay sticking or LN phase short circuit. In applications, the master control chip 15 can be connected with the detection node to realize relay sticking detection and line short circuit detection according to the voltage of the detection node and the conduction state of the relay on the corresponding line.

[0070] When the L-phase relay S1 is disconnected, the electrical signal of the detection node jumps from the first level to the second level, indicating that there is an L-phase relay sticking. When the L-phase relay is disconnected and the N-phase relay S2 is closed, the electrical signal of the detection node jumps from the first level to the second level, indicating that there is an L-N phase short circuit. Exemplarily, the first level can be a high level, and the second level can be a low level. When the N-phase relay S2 is disconnected, the electrical signal of the detection node jumps to a low level, indicating that there is an L-phase relay sticking. When the N-phase relay S2 is closed, the electrical signal of the detection node jumps to a low level, indicating that there is an L-N phase short circuit.

[0071] As shown in Figure 2 The L-phase relay S1 on the L-phase line (fire wire) can control the on-off of the L-phase line, and if the L-phase relay S1 sticks, the relay will remain in the conduction state, Figure 2 The OUT L1 end of the L-phase line is connected with the detection circuit L1 end. Similarly, as Figure 3As shown, the N-phase relay S2 on the N-phase line (zero line) can control the on-off of the N-phase line. It can be understood that, in the case that the first switching unit 112 is turned on, whether the detection module 13 has the electrical signal input by the L-phase line can be detected based on the voltage of the detection node. Since the L-phase line connected with the detection circuit will not input the electrical signal in the case of being disconnected, it can be determined whether the L-phase line actually is in the disconnected state. In the case that the relay on the L-phase line is disconnected, the main control chip 15 outputs the driving signal Vd to the switching control module 12, and the switching control module 12 drives the control unit 111 to emit the first control signal, so that the first switching unit 112 is turned on. If the voltage of the detection node changes after the first switching unit 112 is turned on, it can be determined that the L-phase line actually is not in the disconnected state, and it can be determined that the relay on the L-phase line is in the sticking state, thereby realizing the relay sticking detection. If the voltage of the detection node does not change after the first switching unit 112 is turned on, it can be determined that the L-phase line actually is in the disconnected state, and it can be determined that the relay on the L-phase line is not in the sticking state.

[0072] In the case that the L-phase relay S1 on the corresponding L-phase line is disconnected and the N-phase relay S2 on the N-phase line is turned on, the main control chip 15 outputs the driving signal Vd to the switching control module 12, and the switching control module 12 drives the control unit 111 to emit the first control signal, so that the first switching unit 112 is turned on. If the voltage of the detection node changes, it indicates that the voltage signal on the N-phase line is input to the detection circuit through the L-phase line, which causes the voltage of the detection node to change, and finally it can be determined that the output end of the L-phase line is short-circuited with the N-phase line, thereby realizing the short-circuit detection between the L-phase line and the N-phase line. If the voltage of the detection node does not change, it can be determined that the output end of the L-phase line is not short-circuited with the N-phase line.

[0073] In applications, for a multi-phase circuit with multiple L-phase lines, short-circuit detection between the L-phase lines is also needed. In this case, the number of detection circuits needs to be adapted according to the number of L-phase lines, so that each L-phase line is connected with each detection circuit one by one. For the short-circuit detection between the L-phase lines, the L-phase relay S1 on one L-phase line can be turned on, and the L-phase relays S1 on the other L-phase lines are disconnected. The short-circuit condition can be determined according to the voltage of the detection node corresponding to the other L-phase lines. If the voltage of the detection node corresponding to the target L-phase line changes, it can be determined that the target L-phase line is short-circuited with the reference L-phase line. The switching state of the L-phase relay S1 on each L-phase line is controlled, and the short-circuit condition between the L-phase lines can be determined based on the voltage of each detection node, thereby realizing the short-circuit detection between the L-phase lines.

[0074] It should be further noted that, for the charging pile, the relay sticking detection can be performed in the non-charging scene (before charging or after charging is completed), and the line short circuit detection can be performed before the vehicle enters the charging after the gun is inserted.

[0075] The detection circuit includes a relay module 11, a switch control module 12, and a detection module 13. The relay module 11 includes a control unit 111 and a first switch unit 112. The first end of the first switch unit 112 is connected to the output end of the L-phase line, and the second end of the first switch unit 112 is connected to the detection module 13. After the switch control module 12 responds to the driving signal Vd to turn on the power supply path of the control unit 111, the control unit 111 transmits a first control signal to the first switch unit 112. The first switch unit 112 responds to the first control signal to turn on, and the L-phase line is connected to the detection module 13. Since the voltage of the detection node in the detection module 13 changes when the detection module 13 receives the electrical signal input by the L-phase line, whether the L-phase line transmits the voltage signal to the detection module 13 can be determined by detecting whether the voltage of the detection node changes. Based on this, the relay sticking detection and the line short circuit detection can be realized according to the on-off state of each relay and the voltage state of the detection node, so that the relay sticking detection and the line short circuit detection can be realized by one type of detection circuit, without using different types of detection circuits for relay sticking detection and line short circuit detection.

[0076] In one embodiment, as shown in Figure 4 and Figure 5 The control unit 111 includes a first light emitting device 1111, and the first switch unit 112 includes a photosensitive switch 1121.

[0077] The two ends of the first light emitting device 1111 are respectively connected to the switch control module 12. The first end of the photosensitive switch 1121 is connected to the output end of the L-phase line, and the second end of the photosensitive switch 1121 is connected to the detection module 13. The photosensitive switch 1121 is turned on to connect the L-phase line and the detection module 13 when it receives the light signal.

[0078] The relay module 11 can be an optical coupling relay. The first light emitting device 1111 is used to emit a light signal as a first control signal, and the first light emitting device 1111 can be a light emitting diode (LED). The photosensitive switch 1121 can be a photosensitive transistor, a phototriode Q1, a thyristor, or other types of elements.

[0079] It can be understood that, in the case that the switch control circuit receives the driving signal Vd to turn on the power supply path of the first light emitting device 1111, the first light emitting device 1111 will receive an electrical signal, the first light emitting device 1111 will emit a light signal, the light signal will irradiate on the photosensitive switch 1121 through the air gap, so that the photosensitive switch 1121 is turned on. Since the first end of the photosensitive switch 1121 is connected with the output end of the L-phase line, and the second end of the photosensitive switch 1121 is connected with the detection module 13, the photosensitive switch 1121 is turned on, which will turn on the connection between the L-phase line and the detection module 13, so that the detection module 13 can receive the electrical signal from the L-phase line, so as to realize the relay sticking detection and the line short circuit detection according to the voltage of the detection node M1 and the on-off state of the relay on the corresponding line.

[0080] It should be noted that the volume of the optocoupler relay is small, and the use of the optocoupler relay in the relay module 11 is conducive to reducing the occupied space of the detection circuit, and the detection circuit is more easily integrated into various miniaturized electronic devices and circuit boards, thereby improving the overall integration of the device.

[0081] In one embodiment, the photosensitive switch 1121 includes a photovoltaic diode and a field effect tube, the photovoltaic diode is connected with the gate of the field effect tube, the first pole of the field effect tube is connected with the output end of the L-phase line, and the second pole of the field effect tube is connected with the detection module 13.

[0082] The photovoltaic diode is used to receive the light emitted by the light emitting diode. When light shines on the photovoltaic diode, a voltage is generated therein, thereby realizing the conversion of the light signal to the electrical signal. The field effect tube can be a metal oxide semiconductor field effect tube (MOSFET), and the drain and source of the field effect tube can not be distinguished. Therefore, the first pole of the field effect tube can be any one of the drain and the source, and the second pole of the field effect tube is the other one. The voltage generated by the photovoltaic diode is applied to the gate of the field effect tube, so that the drain and the source of the field effect tube are turned on, and the photosensitive switch 1121 is turned on.

[0083] It can be understood that, in the case that the switch control circuit receives the driving signal Vd to turn on the power supply path to the first light emitting device 1111, the first light emitting device 1111 receives the electrical signal, the first light emitting device 1111 emits the light signal, the light signal irradiates on the photovoltaic diode through the gap, and the voltage generated by the photovoltaic diode is applied to the gate of the field effect tube to make the first pole and the second pole of the field effect tube conductive. Since the first pole of the field effect tube is connected with the output end of the L-phase line, and the second pole of the field effect tube is connected with the detection module 13, when the first pole and the second pole of the field effect tube are conductive, the output end of the L-phase line is conductively connected with the detection module 13, so that the detection module 13 can receive the electrical signal from the L-phase line, so as to realize the relay sticking detection and the line short circuit detection according to the voltage of the detection node M1 and the conduction state of the relay on the corresponding line.

[0084] In another embodiment, as shown in Figure 6 and Figure 7 , the control unit 111 includes an electromagnet 1112, and the first switch unit 112 includes a contact switch 1122.

[0085] The two ends of the electromagnet 1112 are respectively connected with the switch control module 12, for generating an electromagnetic force to attract the movable contact of the contact switch 1122 when receiving the power supply of the switch control module 12, so as to make the contact switch 1122 conductive. The first end of the contact switch 1122 is connected with the output end of the L-phase line, and the second end of the contact switch 1122 is connected with the detection module 13.

[0086] Among them, the relay module 11 can be an electromagnetic relay. The electromagnet 1112 can generate an electromagnetic signal after being powered on, and attract the movable contact of the contact switch 1122 by electromagnetic force, so as to make the contact switch 1122 conductive.

[0087] It can be understood that, in the case that the switch control circuit receives the driving signal Vd to turn on the power supply path to the electromagnet 1112, the electromagnet 1112 is powered on to attract the movable contact of the contact switch 1122, so as to make the contact switch 1122 conductive. Since the first end of the contact switch 1122 is connected with the output end of the L-phase line, and the second end of the contact switch 1122 is connected with the detection module 13, when the contact switch 1122 is conductive, the L-phase line is conductively connected with the detection module 13, so that the detection module 13 can receive the electrical signal from the L-phase line, so as to realize the relay sticking detection and the line short circuit detection according to the voltage of the detection node M1 and the conduction state of the relay on the corresponding line.

[0088] In one embodiment, as shown in Figures 4 to 7 , the switch control module 12 includes a first current limiting unit 121 and a second switch unit 122.

[0089] The first current-limiting unit 121 is configured to receive the first power signal VCC1 and is connected to both ends of the control unit 111. The first end of the second switch unit 122 is connected to the first current-limiting unit 121, and the second end of the second switch unit 122 is connected to the common ground. The second switch unit 122 is configured to be turned on to connect the first current-limiting unit 121 and the common ground in response to the driving signal Vd.

[0090] It can be understood that, since the first current-limiting unit 121 receives the first power signal VCC1 and is connected to both ends of the control unit 111, the first end of the second switch unit 122 is connected to the first current-limiting unit 121, and the second end of the second switch unit 122 is connected to the common ground, the first current-limiting unit 121, the second switch unit 122, and the common ground form a power supply loop for the control unit 111. When the second switch unit 122 is turned on to connect the first current-limiting unit 121 and the common ground in response to the driving signal Vd, the power supply loop is turned on, and the first power signal VCC1 supplies power to the control unit 111, so that the control unit 111 sends out the first control signal, and the first switch unit 112 is turned on in response to the first control signal, thereby realizing the on-off control of the first switch unit 112, that is, realizing the on-off control of the L-phase line and the detection module 13. In addition, the current-limiting unit 14 can limit the current of the power supply loop to avoid damage to the control unit 111 and the second switch unit 122 due to excessive current.

[0091] In one example, the second switch unit 122 can include a transistor Q1, a first resistor R1, and a second resistor R2. The base of the transistor Q1 is connected to the main control chip 15 through the first resistor R1. The main control chip 15 can output the driving signal Vd to the first resistor R1, and the driving signal Vd is transmitted to the base of the transistor Q1 through the first resistor R1, thereby controlling the on-off of the transistor Q1. The collector of the transistor Q1 is connected to the second end of the control unit 111 and the first current-limiting unit 121 as the first end of the second switch unit 122. The emitter of the transistor Q1 is connected to the common ground as the second end of the second switch unit 122. The second resistor R2 is arranged between the base and the collector of the transistor Q1, and the second resistor R2 is also used to protect the safety of the transistor Q1.

[0092] In one embodiment, the first current-limiting unit 121 includes a first current-limiting resistor R01 and a protection diode D1.

[0093] The first end of the first current-limiting resistor R01 is configured to receive the first power signal VCC1. The negative electrode of the protection diode D1 is connected to the second end of the first current-limiting resistor R01 and the first end of the control unit 111. The positive electrode of the protection diode D1 is connected to the second end of the control unit 111 and the first end of the second switch unit 122, respectively.

[0094] It can be understood that the current of the power supply circuit can be reduced through the first current-limiting resistor R01, and the control unit 111 can be divided by voltage to realize the protection of the control unit 111 and the second switch unit 122. By setting the protection diode D1, connecting the negative electrode of the protection diode D1 to the first end of the control unit 111, and connecting the positive electrode of the protection diode D1 to the second end of the control unit 111, a freewheeling circuit can be formed between the control unit 111 and the protection diode D1 after the second switch unit 122 is turned off, reducing the risk of damage to the control unit 111 caused by the sudden turn-off of the second switch unit 122, and ensuring the safety of the control unit 111.

[0095] In one embodiment, as shown in Figure 4 and Figure 6 The detection module 13 includes a second current-limiting unit 131, an optical coupling isolation unit 132, and a first detection unit 133.

[0096] The second current-limiting unit 131 is connected to the second end of the first switch unit 112, and is configured to perform current-limiting processing on the input electrical signal when the first switch unit 112 is turned on.

[0097] The optical coupling isolation unit 132 includes a second light-emitting device 1321 and a light-sensitive device 1322, and the two ends of the second light-emitting device 1321 are connected to the second current-limiting unit 131. The second light-emitting device 1321 can be a light-emitting diode, and the light-sensitive device 1322 can be a light-sensitive transistor, a phototriode Q1, or other types of elements. For example, the light-sensitive device 1322 can be a phototriode Q1. When the second light-emitting device 1321 is powered and emits light, the light-sensitive device 1322 receives the light signal and turns on.

[0098] The first detection unit 133 is configured to receive a second power signal VCC2 and is connected to the two ends of the light-sensitive device 1322 and the common ground, respectively. The detection node M1 of the first detection unit 133 serves as the detection node M1 of the detection module 13, and the voltage of the detection node M1 changes when the light-sensitive device 1322 is turned on. The input of the second power signal VCC2 to the first detection unit 133 can give the detection node M1 an initial voltage, and after the light-sensitive device 1322 is turned on, the corresponding circuit involving the detection node M1 in the first detection unit 133 can be turned on to change the voltage of the detection node M1.

[0099] It can be understood that after the first switch unit 112 is turned on, the electrical signal input by the L-phase line is input to the second light-emitting device 1321 through the second current-limiting unit 131, the second light-emitting device 1321 is powered to emit light, and the photosensitive device 1322 receives the light signal to be turned on. Since the voltage of the detection node M1 changes when the photosensitive device 1322 is turned on, the voltage of the detection node M1 will change after the photosensitive device 1322 receives the light signal to be turned on. Therefore, after the first switch unit 112 is turned on, whether the L-phase line has an input electrical signal can be determined by detecting whether the voltage of the detection node M1 changes, that is, whether the L-phase line is in an open state. On this basis, the master control chip 15 can realize the relay sticking detection and the line short circuit detection based on the switching state of each relay and the voltage of the detection node M1.

[0100] In one example, the second current-limiting unit 131 includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected with the second end of the first switch unit 112, and the second end of the third resistor R3 is connected with the first end of the second light-emitting device 1321. The first end of the fourth resistor R4 is connected with the second end of the third resistor R3 and the first end of the second light-emitting device 1321 respectively, and the second end of the fourth resistor R4 is connected with the second end of the second light-emitting device 1321 and the common ground end respectively. The third resistor R3 and the fourth resistor R4 are matched to realize voltage division and current limiting of the second light-emitting device 1321, so as to protect the second light-emitting device 1321.

[0101] In another example, the optical coupling isolation unit 132 can include the photosensitive device 1322 and two second light-emitting devices 1321, the two second light-emitting devices 1321 being a first light-emitting diode and a second light-emitting diode respectively, the positive electrode of the first light-emitting diode being connected with the second end of the third resistor R3 and the first end of the fourth resistor R4 respectively, the negative electrode of the second light-emitting diode being connected with the second end of the third resistor R3 and the first end of the fourth resistor R4 respectively, and the negative electrode of the first light-emitting diode and the positive electrode of the second light-emitting diode being connected with the second end of the fourth resistor R4 respectively. With the above structure, any one of the first light-emitting diode and the second light-emitting diode emits light, and the photosensitive device 1322 is turned on by the light signal.

[0102] In one embodiment, as shown in Figure 4 and Figure 6 the first detection unit 133 includes a first voltage dividing resistor R11, a first voltage stabilizing capacitor C1 and a first grounding resistor R21.

[0103] The first voltage division resistor R11 is configured to receive the second power supply signal VCC2. The first end of the first voltage stabilizing capacitor C1 is connected to the second end of the first voltage division resistor R11 and the first end of the photosensitive device 1322, and serves as a detection node M1. The first end of the first grounding resistor R21 is connected to the second end of the photosensitive device 1322 and the second end of the voltage stabilizing capacitor, and the second end of the first grounding resistor R21 is connected to a common ground.

[0104] It can be understood that the detection node M1 is located at the first end of the first voltage stabilizing capacitor C1, and the first end of the first voltage stabilizing capacitor C1 is connected to the second end of the first voltage division resistor R11. Since the first voltage division resistor R11 receives the second power supply signal VCC2, the detection node M1 will have an initial voltage under the influence of the second power supply signal VCC2. Since the second end of the first voltage stabilizing capacitor C1 is connected to the common ground through the first grounding resistor R21, and based on the characteristics of the capacitor, the voltage at the first end of the first voltage stabilizing capacitor C1 is stable, i.e., the voltage at the detection node M1 is stable, without changing the state of the circuit. Since the first end of the first voltage stabilizing capacitor C1 is connected to the first end of the photosensitive device 1322, and the second end of the first voltage stabilizing capacitor C1 is connected to the second end of the photosensitive device 1322, it is obvious that the detection node M1 is grounded through the first grounding resistor R21 when the photosensitive device 1322 is turned on, and the voltage at the detection node M1 will change. The photosensitive device 1322 will only be turned on when the L-phase line input signal is input to the detection module 13. Therefore, whether the voltage at the detection node M1 changes can be used to detect whether the L-phase line input signal is input. The state of each relay and whether the L-phase line input signal is input can be used to realize the relay sticking detection and the line short circuit detection. Therefore, based on the switching state of each relay and the voltage at the detection node M1, the relay sticking detection and the line short circuit detection can be realized, and the detection circuit of the embodiment can realize the relay sticking detection and the line short circuit detection.

[0105] In another embodiment, as shown in Figure 5 and Figure 7 The detection module 13 includes a third current limiting unit 134 and a second detection unit 135.

[0106] The first end of the third current limiting unit 134 is connected to the second end of the first switching unit 112.

[0107] The second detection unit 135 is configured to receive a second power signal VCC2 and connected with the second end of the third current limiting unit 134 and the common ground, respectively. The detection node M1 of the second detection unit 135 is configured to be the detection node M1 of the detection module 13, and the voltage of the detection node M1 changes when the second detection unit 135 receives the electrical signal input by the L-phase line. The input of the second power signal VCC2 can make the detection node M1 have an initial voltage, and the voltage of the detection node M1 changes after the second detection unit 135 receives the electrical signal input by the L-phase line and is affected by the external signal.

[0108] It can be understood that the first end of the third current limiting unit 134 is connected with the second end of the first switch unit 112, and the second end of the third current limiting unit 134 is connected with the second detection unit 135. The third current limiting unit 134 can limit the current of the electrical signal input by the first switch unit 112 to avoid damage to the second detection unit 135 caused by receiving too high current. After the first switch unit 112 is turned on, the electrical signal input by the L-phase line is input to the second detection unit 135 through the third current limiting unit 134. Since the voltage of the detection node M1 changes when the second detection unit 135 receives the electrical signal input by the L-phase line. Therefore, after the first switch unit 112 is turned on, whether the L-phase line has an input electrical signal can be determined by detecting whether the voltage of the detection node M1 changes, that is, whether the L-phase line is in an open state. On this basis, the master control chip 15 can realize the relay sticking detection and the line short circuit detection based on the switching state of each relay and the voltage of the detection node M1.

[0109] In one embodiment, as shown in Figure 5 and Figure 7 The third current limiting unit 134 includes at least one second current limiting resistor R02 and a second ground resistor R22. Each second current limiting resistor R02 is connected in series between the second end of the first switch unit 112 and the detection node M1. The first end of the second ground resistor R22 is connected with the detection node M1, and the second end of the second ground resistor R22 is connected with the common ground.

[0110] In application, a plurality of second current limiting resistors R02 can be connected in series between the second end of the first switch unit 112 and the detection node M1 to increase the resistance of the plurality of second current limiting resistors R02, reduce the current received by the second detection unit 135, and protect the second detection unit 135. By arranging the second ground resistor R22, the anti-interference ability of the circuit can be improved to improve the stability and reliability of the circuit.

[0111] In one embodiment, as shown in Figure 5 and Figure 7 The second detection unit 135 includes a second voltage dividing resistor R12 and a second voltage stabilizing capacitor C2

[0112] The second voltage dividing resistor R12 is configured to receive a second power signal VCC2.

[0113] The first end of the second voltage stabilizing capacitor C2 is connected with the second end of the second voltage dividing resistor R12 and the second end of the third current limiting unit 134 respectively, and serves as a detection node M1, and the second end of the second voltage stabilizing capacitor C2 is connected with a common ground.

[0114] It can be understood that the detection node M1 is located at the first end of the second voltage stabilizing capacitor C2, and the first end of the second voltage stabilizing capacitor C2 is connected with the second end of the second voltage dividing resistor R12 respectively. Since the second voltage dividing resistor R12 receives the second power signal VCC2, the detection node M1 will have an initial voltage under the influence of the second power signal VCC2. Since the second end of the second voltage stabilizing capacitor C2 is connected with the common ground, based on the characteristics of the capacitor, the voltage at the second end of the voltage stabilizing capacitor can be ensured to be stable, i.e., the voltage at the detection node M1 is stable. Since the first end of the second voltage stabilizing capacitor C2 is connected with the second end of the third current limiting unit 134, obviously, after the L-phase line input electrical signal is input to the third current limiting unit 134 and then input to the detection node M1 through the third current limiting unit 134, the voltage at the detection node M1 will change, and thus whether the L-phase line inputs the electrical signal can be detected by detecting whether the voltage at the detection node M1 changes. The state of each relay and whether the L-phase line inputs the electrical signal can be determined, and thus the relay sticking detection and the line short circuit detection can be realized. Therefore, based on the switching state of each relay and the voltage at the detection node M1, the relay sticking detection and the line short circuit detection can be realized, and the detection circuit in the embodiment can realize the relay sticking detection and the line short circuit detection.

[0115] The embodiment of the present application further provides a three-phase detection circuit, comprising three detection circuits as described in any of the above solutions, and the three detection circuits are connected with the output ends of three L-phase lines in a three-phase alternating current circuit respectively.

[0116] The three-phase detection circuit comprises three detection circuits as described in any of the above solutions.

[0117] It is understandable that for the three L-phase lines in a three-phase AC line, the L-phase relays on each of the three L-phase lines can be sequentially checked for relay sticking. The three L-phase lines can be L1, L2, and L3. When the L1 phase relay is open, the voltage change at the detection node is detected after the first switch unit 112 in the corresponding detection circuit is turned on. This confirms that the L1 phase line is not actually open, and therefore the relay on the L1 phase line is stuck. Similarly, when the L2 phase relay is open, the voltage change at the detection node is detected after the first switch unit 112 in the corresponding detection circuit is turned on. This confirms that the L2 phase line is not actually open, and therefore the relay on the L2 phase line is stuck. Likewise, when the L3 phase relay is open, the voltage change at the detection node is detected after the first switch unit 112 in the corresponding detection circuit is turned on. This confirms that the L3 phase line is not actually open, and therefore the relay on the L3 phase line is stuck.

[0118] For three-phase AC lines, short-circuit detection between L-phase lines is also required. For short-circuit detection between the three L-phase lines, the L-phase relay S1 on one L-phase line can be turned on, using that L-phase line as the reference L-phase line. The L-phase relays S1 on the other L-phase lines are turned off. The short-circuit condition is determined based on the voltage at the detection nodes corresponding to the other L-phase lines. If the voltage at the detection node corresponding to the target L-phase line changes, a short circuit between the target L-phase line and the reference L-phase line can be determined. By controlling the switching state of the L-phase relays S1 on each L-phase line and based on the voltage conditions at each detection node, the short-circuit condition between L-phase lines can be determined, thus achieving short-circuit detection between L-phase lines.

[0119] The aforementioned three-phase detection circuit includes three detection circuits as described in any of the above schemes. Each of the three detection circuits is connected to one of the three L-phase lines in the three-phase AC line. These three detection circuits can then be used to detect relay sticking on the three L-phase lines, as well as short-circuit detection between the three L-phase lines and the N-phase line. When the relays on the three L-phase lines are not stuck, the control circuit closes some of the relays on the L-phase lines and opens others. Based on the on / off status of each relay and the voltage at detection node M1, short-circuit detection between the L-phase lines can be achieved. Thus, relay sticking detection and short-circuit detection between lines can be achieved using a single type of detection circuit, eliminating the need for separate detection circuits of different types.

[0120] This application also provides a charging pile, such as... Figure 8 As shown, the charging pile includes: a main control chip 15 and a detection circuit as described above. The main control chip 15 is connected to the detection circuit. The main control chip 15 is used to output a drive signal Vd and receive the voltage signal of the detection node.

[0121] It can be understood that, since the charging pile adopts all the technical solutions of the above-mentioned embodiments, it has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0122] In one embodiment, the charging pile further comprises a prompting unit, the prompting unit being electrically connected with the master control chip 15, and the prompting unit being used to send a prompt information.

[0123] The prompt information can include at least one of sound information, light information and vibration information.

[0124] In the application, the master control chip 15 can realize the relay sticking detection and the line short circuit detection according to the voltage of the detection node and the conduction state of the relay on the corresponding line, and when it is determined that the charging pile has an abnormal condition (for example, the relay sticking), the master control chip 15 can control the prompting unit to send a prompt information to timely prompt the user of the fault condition, so that the user can subsequently take corresponding measures.

[0125] The above-mentioned is only an exemplary embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A detection circuit, characterized by, The detection circuit comprises: A relay module comprising a control unit and a first switching unit, a first end of the first switching unit being connected to an output end of an L-phase line, the control unit being configured to emit a first control signal, and the first switching unit being configured to be turned on in response to the first control signal; A switching control module connected to two ends of the control unit, the switching control module being configured to turn on a power supply path of the control unit in response to a driving signal, so that the control unit emits the first control signal; A detection module connected to a second end of the first switching unit, the detection module being configured to perform limiting processing on an input signal, wherein the detection module has a detection node, and a voltage of the detection node changes when the detection module receives an electrical signal input by the L-phase line, indicating that there is a relay sticking or LN-phase short circuit; When the L-phase relay is disconnected, the electrical signal of the detection node jumps from a first level to a second level, indicating that there is an L-phase relay sticking; when the L-phase relay is disconnected and the N-phase relay is closed, the electrical signal of the detection node jumps from the first level to the second level, indicating that there is an LN-phase short circuit.

2. The detection circuit of claim 1, wherein, The control unit comprises a first light-emitting device, and the first switching unit comprises a photosensitive switch; Two ends of the first light-emitting device are respectively connected to the switching control module; A first end of the photosensitive switch is connected to the output end of the L-phase line, and a second end of the photosensitive switch is connected to the detection module, and the photosensitive switch is turned on to connect the L-phase line and the detection module when receiving an optical signal.

3. The detection circuit of claim 2, wherein, The photosensitive switch comprises a photovoltaic diode and a field effect transistor, the photovoltaic diode is connected to a gate of the field effect transistor, a first pole of the field effect transistor is connected to the output end of the L-phase line, and a second pole of the field effect transistor is connected to the detection module.

4. The detection circuit of claim 1, wherein, The control unit comprises an electromagnet, and the first switching unit comprises a contact switch; Two ends of the electromagnet are respectively connected to the switching control module, and the electromagnet is configured to generate an electromagnetic force to attract a moving contact of the contact switch when receiving power supply of the switching control module, so that the contact switch is turned on; A first end of the contact switch is connected to the output end of the L-phase line, and a second end of the contact switch is connected to the detection module.

5. The detection circuit of claim 1, wherein, The switching control module comprises: A first current limiting unit configured to receive a first power signal and connected to two ends of the control unit; A second switching unit, a first end of the second switching unit being connected to the first current limiting unit, and a second end of the second switching unit being connected to a common ground, the second switching unit being configured to be turned on to connect the first current limiting unit and the common ground in response to the driving signal.

6. The detection circuit of claim 5, wherein, The first current limiting unit comprises: A first current limiting resistor, a first end of the first current limiting resistor being configured to receive a first power signal; A protection diode, a negative electrode of the protection diode being connected to a second end of the first current limiting resistor and a first end of the control unit, and a positive electrode of the protection diode being respectively connected to a second end of the control unit and a first end of the second switching unit.

7. The detection circuit of claim 1, wherein, The detection module comprises: A second current limiting unit is connected with the second end of the first switch unit; A light coupling isolation unit includes a second light emitting device and a light sensitive device, two ends of the second light emitting device are connected with the second current limiting unit respectively; A first detection unit is used for receiving a second power supply signal and is connected with two ends of the light sensitive device and a common ground terminal respectively, a detection node of the first detection unit is used as a detection node of the detection module, and a voltage of the detection node changes when the light sensitive device is turned on.

8. The detection circuit of claim 7, wherein, The first detection unit includes: A first voltage dividing resistor is used for receiving the second power supply signal; A first voltage stabilizing capacitor has a first end connected with a second end of the first voltage dividing resistor and a first end of the light sensitive device respectively and serving as the detection node; A first grounding resistor has a first end connected with a second end of the light sensitive device and a second end of the voltage stabilizing capacitor respectively, and a second end of the first grounding resistor is connected with the common ground terminal.

9. The detection circuit of claim 1, wherein, The detection module includes: A third current limiting unit has a first end connected with the second end of the first switch unit; A second detection unit is used for receiving a second power supply signal and is connected with a second end of the third current limiting unit and a common ground terminal respectively, a detection node of the second detection unit is used as a detection node of the detection module, and a voltage of the detection node changes when the second detection unit receives an electrical signal input by an L phase line.

10. The detection circuit of claim 9, wherein, The third current limiting unit includes: At least one second current limiting resistor is arranged in series between the second end of the first switch unit and the detection node; A second grounding resistor has a first end connected with the detection node and a second end connected with the common ground terminal.

11. The detection circuit of claim 9, wherein, The second detection unit includes: A second voltage dividing resistor is used for receiving the second power supply signal; A second voltage stabilizing capacitor has a first end connected with a second end of the second voltage dividing resistor and a second end of the third current limiting unit respectively and serving as the detection node, and a second end of the second voltage stabilizing capacitor is connected with the common ground terminal.

12. A three-phase detection circuit, characterized by The three-phase detection circuit includes three detection circuits as claimed in any one of claims 1 to 11, and the three detection circuits are connected with output ends of three L phase lines in a three-phase alternating current circuit respectively.

13. A charging station, characterized in that The charging pile includes a main control chip and a detection circuit as claimed in any one of claims 1 to 11, the main control chip is connected with the detection circuit, the main control chip is used for outputting the driving signal and receiving a voltage signal of the detection node.

Images