Safety protection circuit of charging pile

Abstract

The invention discloses a safety protection circuit of a charging pile, and relates to the technical field of charging pile protection, and the safety protection circuit comprises an intelligent control module which is used for signal receiving and module control; the charging pile module is used for power supply control; the voltage sampling module is used for isolating voltage sampling and signal processing; the abrupt change judgment module is used for phase shift and signal superposition processing; the absolute value module is used for absolute value processing; the abnormity judgment module is used for comparing the input signal with the fault threshold value, and the intelligent control module reduces the voltage value of the fault threshold value; the gating control module is used for controlling a transmission path of a signal; and the anomaly detection module is used for electric energy storage and voltage anomaly judgment. According to the safety protection circuit of the charging pile, power-off protection can be carried out when the sudden change degree exceeds the fault threshold value, the fault threshold value is reduced and the sudden change degree is judged again when the sudden change degree does not exceed the fault threshold value, whether alternating current electric energy provided by the charging pile is abnormal or not can be predicted in advance, and the power supply safety of the charging pile is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of charging pile protection, and in particular to a safety protection circuit for a charging pile. Background Art

[0002] With the rapid development of the electric vehicle industry, charging piles, as the basic charging facilities for electric vehicles, have become increasingly prominent. To ensure the normal power supply of the charging piles, the safety protection circuits of the charging piles in the prior art generally use comparators and threshold devices. The threshold device is used to set the required overvoltage threshold or short-circuit threshold, and when the power voltage provided by the charging pile exceeds the set overvoltage threshold or short-circuit threshold, power-off protection control is performed. This method cannot quickly and effectively determine whether the AC power provided by the charging pile is abnormal when performing overvoltage or short-circuit detection on the AC power, and cannot predict in advance whether the AC power provided by the charging pile is abnormal, which causes certain safety hazards to the charging piles, and therefore needs to be improved. Summary of the invention

[0003] An embodiment of the present invention provides a safety protection circuit for a charging pile to solve the problems raised in the above background technology.

[0004] According to an embodiment of the present invention, a safety protection circuit of a charging pile is provided, comprising: an intelligent control module, a charging pile module, a voltage sampling module, a mutation judgment module, an absolute value module, an abnormality judgment module, a gating control module and an abnormality detection module;

[0005] An intelligent control module is connected to the strobe control module and the abnormality detection module, and is used to provide a start signal, set a first timing time and a second timing time, and when the first abnormality signal transmitted by the strobe control module is not received within the first timing time, the pre-detection signal is outputted on a regular basis, and when the duration of outputting the pre-detection signal exceeds the second timing time, the pre-detection signal is stopped from being outputted, and when the first abnormality signal transmitted by the strobe control module is received or the second abnormality signal is outputted by the abnormality detection module, the start signal is stopped from being outputted;

[0006] A charging pile module, connected to the intelligent control module, the gating control module and the abnormality detection module, for receiving AC power and transmitting AC power to the charging gun when receiving a start signal, and stopping receiving the start signal when receiving a first abnormality signal transmitted by the gating control module or a second abnormality signal output by the abnormality detection module;

[0007] A voltage sampling module, connected to the charging pile module, for performing isolation voltage sampling and signal amplification and filtering processing on the connected AC power and outputting a first sampling signal;

[0008] a mutation judgment module, connected to the voltage sampling module, for performing a 180-degree phase shift on the first sampling signal, detecting the phase-shifted signal and superimposing it with the received first sampling signal, and outputting a first voltage signal;

[0009] an absolute value module, connected to the mutation judgment module, and configured to perform absolute value processing on the first voltage signal and output a second voltage signal;

[0010] an abnormality judgment module, connected to the absolute value module, the intelligent control module and the mutation judgment module, and used to set a fault threshold, output a first abnormality signal when the first voltage signal or the second voltage signal is greater than the fault threshold, and reduce the voltage value of the fault threshold when receiving a pre-detection signal;

[0011] A gating control module, connected to the abnormality judgment module, for transmitting the first abnormality signal to the intelligent control module and the charging pile module, and transmitting the first abnormality signal to the abnormality detection module when receiving the pre-detection signal;

[0012] The abnormality detection module is connected to the gating control module and is used to store energy when receiving the first abnormality signal and the pre-detection signal transmitted by the gating control module and output a second abnormality signal when the stored electric energy reaches a set voltage threshold.

[0013] As a further solution of the present invention: the charging pile module includes a charging pile power interface, a first circuit breaker, a first circuit breaker, a charging gun, a first power supply, a first switch tube and a second switch tube; the intelligent control module includes a first controller;

[0014] Preferably, the first end and the second end of the charging pile power interface are respectively connected to the first moving end and the second moving end of the first circuit breaker, the first static end and the second static end of the first circuit breaker are respectively connected to the first end and the second end of the charging gun, one end of the first circuit breaker is connected to the first power supply, the other end of the first circuit breaker is connected to the collector of the first switch tube, the emitter of the first switch tube and the emitter of the second switch tube are both grounded, the collector of the second switch tube is connected to the base of the first switch tube and the IO1 end of the first controller, and the base of the second switch tube is connected to the selection control module and the abnormality detection module.

[0015] As a further solution of the present invention: the voltage sampling module includes a first mutual inductor and a signal processing device; the mutation judgment module includes a first resistor, a second resistor, a first capacitor, a second capacitor, a seventh resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a first operational amplifier;

[0016] Preferably, the first end and the second end of the first mutual inductor are respectively connected to the first end and the second end of the charging pile power interface, the third end and the fourth end of the first mutual inductor are respectively connected to the first input end and the second input end of the signal processing device, the output end of the signal processing device is connected to the first end of the sixth resistor and is connected to one end of the seventh resistor and the inverting end of the first operational amplifier through the first resistor and the second capacitor in sequence, the in-phase end of the first operational amplifier is connected to one end of the third resistor and is connected to one end of the fifth resistor and the output end of the first operational amplifier through the fourth resistor, the other end of the fifth resistor is connected to the second end of the sixth resistor, the absolute value module and the abnormality judgment module, and the other end of the seventh resistor is connected to the ground end of the signal processing device, the other end of the third resistor and the ground end through the first capacitor and the second resistor in sequence.

[0017] As a further solution of the present invention: the abnormality judgment module includes a first comparator, a second comparator, a second power supply, a ninth resistor, an eighth resistor, a first potentiometer and a third switch tube;

[0018] Preferably, the in-phase end of the second comparator is connected to the absolute value module, the inverting end of the first comparator is connected to the inverting end of the second comparator, one end of the eighth resistor and the collector of the third switch tube and connected to the second power supply through the ninth resistor, the emitter of the third switch tube is connected to one end of the first potentiometer and the slider end, the in-phase end of the first switch tube is connected to the second end of the sixth resistor, the other end of the eighth resistor is connected to the other end of the first potentiometer and the ground end, the base of the third switch tube is connected to the IO2 end of the first controller, and the output end of the first comparator is connected to the output end of the second comparator and the selection control module.

[0019] As a further solution of the present invention: the absolute value module includes an eleventh resistor, a twelfth resistor, a second operational amplifier, a third operational amplifier and a third diode;

[0020] Preferably, the inverting terminal of the second operational amplifier is connected to one end of the twelfth resistor and is connected to the second electrical energy of the sixth resistor through the eleventh resistor, the output terminal of the second operational amplifier is connected to the anode of the third diode, the non-inverting terminal of the second operational amplifier is grounded, the cathode of the third diode is connected to the other end of the twelfth resistor and the non-inverting terminal of the third operational amplifier, and the inverting terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier and the non-inverting terminal of the second comparator.

[0021] As a further solution of the present invention: the gating control module includes a first analog switch, a third power supply, a tenth resistor, a fourth switch tube and a first diode;

[0022] Preferably, the IN1 and IN2 terminals of the first analog switch are both connected to the output terminal of the first comparator, the OUT1 terminal of the first analog switch is connected to the IO3 terminal of the first controller and the anode of the first diode, the cathode of the first diode is connected to the base of the second switch tube, the CTRL1 terminal of the first analog switch is connected to the collector of the fourth switch tube and is connected to the third power supply through the tenth resistor, the emitter of the fourth switch tube is grounded, the base of the fourth switch tube is connected to the CTRL2 terminal of the first analog switch and the IO2 terminal of the first controller, and the OUT2 terminal of the first analog switch is connected to the abnormality detection module.

[0023] As a further solution of the present invention: the abnormality detection module includes a fourth power supply, a first logic chip, a fifth switch tube, a thirteenth resistor, a third capacitor, a fourteenth resistor, a sixth switch tube, a fifteenth resistor and a second diode;

[0024] Preferably, the A end and the B end of the first logic chip are respectively connected to the OUT2 end of the first analog switch and the IO2 end of the first controller, the Y end of the first logic chip is connected to the base of the fifth switch tube, the collector of the fifth switch tube is connected to the fourth power supply and the collector of the sixth switch tube, the base of the sixth switch tube is connected to one end of the third capacitor, one end of the thirteenth resistor and the emitter of the fifth switch tube through the fourteenth resistor, the other end of the thirteenth resistor is connected to the other end of the third capacitor, one end of the fifteenth resistor and the ground, the emitter of the sixth switch tube is connected to the other end of the fifteenth resistor, the base of the second switch tube and the anode of the second diode, and the cathode of the second diode is connected to the IO4 end of the first controller.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the safety protection circuit of the charging pile of the present invention can detect voltage mutations on the AC power provided by the charging pile by the voltage sampling module and the mutation judgment module, and when the mutation degree exceeds the abnormal judgment module, the charging pile module will be controlled by the selection control module to perform power-off protection. At the same time, when the mutation degree does not exceed the fault threshold set by the abnormal judgment module, the intelligent control module will output a pre-detection signal at a regular time and reduce the size of the fault threshold, and judge through the abnormal detection module that the mutation degree exceeds the fault threshold for a certain time, and when it exceeds, the charging pile module will be controlled in advance to perform power-off protection, so as to predict in advance whether the AC power provided by the charging pile is abnormal, thereby improving the power supply safety of the charging pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 A schematic block diagram of a safety protection circuit for a charging pile provided in an embodiment of the present invention.

[0028] Figure 2 A circuit diagram of a safety protection circuit for a charging pile provided in an embodiment of the present invention.

[0029] Figure 3 A circuit diagram of an absolute value module provided in an embodiment of the present invention.

[0030] Figure 4 A circuit diagram of an abnormality detection module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In one embodiment, see Figure 1 , a safety protection circuit of a charging pile, comprising: an intelligent control module 1, a charging pile module 2, a voltage sampling module 3, a mutation judgment module 4, an absolute value module 5, an abnormality judgment module 6, a gating control module 7 and an abnormality detection module 8;

[0033] Specifically, the intelligent control module 1 is connected to the strobe control module 7 and the abnormality detection module 8, and is used to provide a start signal, set a first timing time and a second timing time, and within the first timing time, when the first abnormality signal transmitted by the strobe control module 7 is not received, the pre-detection signal is outputted on a regular basis, and after the duration of outputting the pre-detection signal exceeds the second timing time, the pre-detection signal is stopped from being outputted, and when the first abnormality signal transmitted by the strobe control module 7 is received or the second abnormality signal is outputted by the abnormality detection module 8, the start signal is stopped from being outputted;

[0034] The charging pile module 2 is connected to the intelligent control module 1, the gating control module 7 and the abnormality detection module 8, and is used to receive the AC power and transmit the AC power to the charging gun when receiving the start signal, and stop receiving the start signal when receiving the first abnormal signal transmitted by the gating control module 7 or the abnormality detection module 8 outputs the second abnormal signal;

[0035] The voltage sampling module 3 is connected to the charging pile module 2 and is used to perform isolation voltage sampling and signal amplification and filtering on the connected AC power and output a first sampling signal;

[0036] The mutation judgment module 4 is connected to the voltage sampling module 3, and is used to perform a 180-degree phase shift on the first sampling signal and detect the phase-shifted signal and perform superposition processing on the received first sampling signal, and output a first voltage signal;

[0037] An absolute value module 5, connected to the mutation judgment module 4, for performing absolute value processing on the first voltage signal and outputting a second voltage signal;

[0038] The abnormality judgment module 6 is connected to the absolute value module 5, the intelligent control module 1 and the mutation judgment module 4, and is used to set a fault threshold. When the first voltage signal or the second voltage signal is greater than the fault threshold, the first abnormality signal is output, and when the pre-detection signal is received, the voltage value of the fault threshold is reduced;

[0039] A gating control module 7, connected to the abnormality judgment module 6, for transmitting the first abnormality signal to the intelligent control module 1 and the charging pile module 2, and transmitting the first abnormality signal to the abnormality detection module 8 when receiving the pre-detection signal;

[0040] The abnormality detection module 8 is connected to the gating control module 7, and is used to store energy when receiving the first abnormality signal and the pre-detection signal transmitted by the gating control module 7, and output a second abnormality signal when the stored electric energy reaches a set voltage threshold.

[0041] In a specific embodiment, the above-mentioned intelligent control module 1 can adopt a microcontroller circuit composed of a single-chip computer and a clock signal, integrating many components such as an operator, a controller, a timer, a memory, and an input and output device to realize functions such as signal processing, data storage, module control, and timing control; the above-mentioned charging pile module 2 can adopt a charging pile circuit composed of a charging pile power interface, a circuit breaker, a charging gun, etc., which can provide AC power connected to the charging pile and control the transmission of AC power; the above-mentioned voltage sampling module 3 can adopt a voltage sampling circuit composed of a voltage transformer and a signal processing device, which can perform isolated voltage sampling and signal amplification and filtering processing; the above-mentioned mutation judgment module 4 can adopt a mutation judgment circuit composed of a resistor, a capacitor, and an operational amplifier to perform a 180-degree phase shift on the input AC signal, and superimpose the phase-shifted signal with the received signal. When no voltage mutation occurs, the potential of the superimposed first voltage signal is zero. The larger the absolute value of the first voltage signal, the greater the degree of mutation. ; The above-mentioned absolute value module 5 can adopt an absolute value circuit composed of an operational amplifier, a resistor and a diode, and can perform absolute value processing on the input negative value signal; the above-mentioned abnormal judgment module 6 can adopt an abnormal judgment circuit composed of a comparator, a resistor, a transistor, etc., and can set a fault threshold. When the first voltage signal is greater than the fault threshold, it means that the voltage mutation degree is large, and the detection sensitivity can be improved by lowering the voltage of the fault threshold; the above-mentioned gating control module 7 can adopt a gating control circuit composed of an analog switch, a resistor, a transistor, etc., and can selectively transmit the input first abnormal signal to the abnormal detection module 8 and the charging pile module 2; the above-mentioned abnormal detection module 8 can adopt an abnormal judgment circuit composed of a logic chip, a transistor, a capacitor, etc., and can perform energy storage when performing voltage mutation prediction work and receiving the first abnormal signal output by the abnormal judgment module 6 transmitted by the gating control module 7. When the stored electrical energy reaches the set voltage threshold, it will output a second abnormal signal, indicating that the voltage mutation is more frequent.

[0042] In another embodiment, see Figure 1 , Figure 2 , Figure 3 and Figure 4 The charging pile module 2 includes a charging pile power interface, a first circuit breaker K1-1, a first circuit breaker K1, a charging gun, a first power supply VCC1, a first switch tube V1 and a second switch tube V2; the intelligent control module 1 includes a first controller U1;

[0043] Specifically, the first end and the second end of the charging pile power interface are respectively connected to the first moving end and the second moving end of the first circuit breaker K1-1, the first static end and the second static end of the first circuit breaker K1-1 are respectively connected to the first end and the second end of the charging gun, one end of the first circuit breaker K1 is connected to the first power supply VCC1, the other end of the first circuit breaker K1 is connected to the collector of the first switch tube V1, the emitter of the first switch tube V1 and the emitter of the second switch tube V2 are both grounded, the collector of the second switch tube V2 is connected to the base of the first switch tube V1 and the IO1 end of the first controller U1, and the base of the second switch tube V2 is connected to the selection control module 7 and the abnormality detection module 8.

[0044] In a specific embodiment, the charging pile power interface receives the AC power provided after being processed by the charging pile; the first circuit breaker K1-1 can adopt a double-pole double-throw switch, which is controlled to close by the first circuit breaker K1 by magnetic attraction; the first switch tube V1 and the second switch tube V2 can both adopt NPN transistors; the first controller U1 can be composed of a single-chip microcomputer and a clock chip.

[0045] Further, the voltage sampling module 3 includes a first mutual inductor PT1 and a signal processing device; the mutation judgment module 4 includes a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a seventh resistor R7, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a first operational amplifier OP1;

[0046] Specifically, the first end and the second end of the first mutual inductor PT1 are respectively connected to the first end and the second end of the charging pile power interface, the third end and the fourth end of the first mutual inductor PT1 are respectively connected to the first input end and the second input end of the signal processing device, the output end of the signal processing device is connected to the first end of the sixth resistor R6 and is connected to one end of the seventh resistor R7 and the inverting end of the first operational amplifier OP1 through the first resistor R1 and the second capacitor C2 in sequence, the in-phase end of the first operational amplifier OP1 is connected to one end of the third resistor R3 and is connected to one end of the fifth resistor R5 and the output end of the first operational amplifier OP1 through the fourth resistor R4, the other end of the fifth resistor R5 is connected to the second end of the sixth resistor R6, the absolute value module 5 and the abnormality judgment module 6, and the other end of the seventh resistor R7 is connected to the ground end of the signal processing device, the other end of the third resistor R3 and the ground end through the first capacitor C1 and the second resistor R2 in sequence.

[0047] In a specific embodiment, the first transformer PT1 may be a voltage transformer; the signal processing device may be composed of an operational amplifier, a resistor and a capacitor to perform signal amplification and filtering processing; the first operational amplifier OP1 may be an OP07 operational amplifier.

[0048] Furthermore, the abnormality judgment module 6 includes a first comparator A1, a second comparator A2, a second power supply VCC2, a ninth resistor R9, an eighth resistor R8, a first potentiometer RP1 and a third switch tube V3;

[0049] Specifically, the in-phase end of the second comparator A2 is connected to the absolute value module 5, the inverting end of the first comparator A1 is connected to the inverting end of the second comparator A2, one end of the eighth resistor R8 and the collector of the third switch tube V3 and connected to the second power supply VCC2 through the ninth resistor R9, the emitter of the third switch tube V3 is connected to one end of the first potentiometer RP1 and the slider end, the in-phase end of the first switch tube V1 is connected to the second end of the sixth resistor R6, the other end of the eighth resistor R8 is connected to the other end of the first potentiometer RP1 and the ground end, the base of the third switch tube V3 is connected to the IO2 end of the first controller U1, and the output end of the first comparator A1 is connected to the output end of the second comparator A2 and the selection control module 7.

[0050] In a specific embodiment, the first comparator A1 and the second comparator A2 can both use LM358 comparators; the second power supply VCC2, the ninth resistor R9 and the eighth resistor R8 set the fault threshold, and cooperate with the third switch tube V3 and the first potentiometer RP1 to adjust the voltage of the fault threshold, wherein the third switch tube V3 can use an NPN transistor.

[0051] Further, the absolute value module 5 includes an eleventh resistor R11, a twelfth resistor R12, a second operational amplifier OP2, a third operational amplifier OP3 and a third diode D3;

[0052] Specifically, the inverting end of the second operational amplifier OP2 is connected to one end of the twelfth resistor R12 and is connected to the second electric energy of the sixth resistor R6 through the eleventh resistor R11, the output end of the second operational amplifier OP2 is connected to the anode of the third diode D3, the non-inverting end of the second operational amplifier OP2 is grounded, the cathode of the third diode D3 is connected to the other end of the twelfth resistor R12 and the non-inverting end of the third operational amplifier OP3, and the inverting end of the third operational amplifier OP3 is connected to the output end of the third operational amplifier OP3 and the non-inverting end of the second comparator A2.

[0053] In a specific embodiment, both the first operational amplifier OP1 and the second operational amplifier OP2 may be made of LT1078 chips.

[0054] Further, the gating control module 7 includes a first analog switch IC1, a third power supply VCC3, a tenth resistor R10, a fourth switch tube V4 and a first diode D1;

[0055] Specifically, the IN1 terminal and the IN2 terminal of the first analog switch IC1 are both connected to the output terminal of the first comparator A1, the OUT1 terminal of the first analog switch IC1 is connected to the IO3 terminal of the first controller U1 and the anode of the first diode D1, the cathode of the first diode D1 is connected to the base of the second switch tube V2, the CTRL1 terminal of the first analog switch IC1 is connected to the collector of the fourth switch tube V4 and is connected to the third power supply VCC3 through the tenth resistor R10, the emitter of the fourth switch tube V4 is grounded, the base of the fourth switch tube V4 is connected to the CTRL2 terminal of the first analog switch IC1 and the IO2 terminal of the first controller U1, and the OUT2 terminal of the first analog switch IC1 is connected to the abnormality detection module 8.

[0056] In a specific embodiment, the first analog switch IC1 may be a CD4066 chip; the fourth switch tube V4 may be an NPN transistor.

[0057] Further, the abnormality detection module 8 includes a fourth power supply VCC4, a first logic chip J1, a fifth switch tube V5, a thirteenth resistor R13, a third capacitor C3, a fourteenth resistor R14, a sixth switch tube V6, a fifteenth resistor R15 and a second diode D2;

[0058] Specifically, the A end and the B end of the first logic chip J1 are respectively connected to the OUT2 end of the first analog switch IC1 and the IO2 end of the first controller U1, the Y end of the first logic chip J1 is connected to the base of the fifth switch tube V5, the collector of the fifth switch tube V5 is connected to the fourth power supply VCC4 and the collector of the sixth switch tube V6, the base of the sixth switch tube V6 is connected to one end of the third capacitor C3, one end of the thirteenth resistor R13 and the emitter of the fifth switch tube V5 through the fourteenth resistor R14, the other end of the thirteenth resistor R13 is connected to the other end of the third capacitor C3, one end of the fifteenth resistor R15 and the ground, the emitter of the sixth switch tube V6 is connected to the other end of the fifteenth resistor R15, the base of the second switch tube V2 and the anode of the second diode D2, and the cathode of the second diode D2 is connected to the IO4 end of the first controller U1.

[0059] In a specific embodiment, the first logic chip J1 can be an AND gate chip; the fifth switch tube V5 and the sixth switch tube V6 can be NPN transistors; the third capacitor C3 can be an energy storage capacitor, which cooperates with the fourteenth resistor R14 and the thirteenth resistor R13 to trigger the sixth switch tube V6 to turn on when the stored electric energy voltage reaches the trigger voltage of the sixth switch tube V6.

[0060] In a safety protection circuit of a charging pile in this embodiment, AC power is connected to the charging pile power interface, the IO1 terminal of the first controller U1 outputs a start signal to control the first switch tube V1 to be turned on, the first circuit breaker K1 is powered on and controls the first circuit breaker K1-1 to be closed, and the AC power is transmitted to the charging gun. The first transformer PT1 samples the isolation voltage of the AC power, and after the signal is processed by the signal processing device, a first sampling signal is output. The first sampling signal is passed through the first operational amplifier OP1, the first resistor R1, the second resistor R2, the first capacitor C1, the third resistor R3, the second capacitor C2, the fourth resistor R4 and the fifth After the resistor R5 performs 180 degree phase shift, the first sampling signal transmitted by the sixth resistor R6 is subjected to signal superposition processing, and a first voltage signal is output. When the potential of the first voltage signal is zero, it indicates that the AC power is stable. The second operational amplifier OP2 cooperates with the eleventh resistor R11, the second resistor R2, the third diode D3 and the third operational amplifier OP3 to perform absolute value processing on the first voltage signal in the negative state, and outputs a second voltage signal. When the first voltage signal or the second voltage signal is greater than the fault threshold set by the second power supply VCC2, the ninth resistor R9 and the eighth resistor R8, the first comparator A1 or the second comparator A2 will output a first abnormal The first analog switch IC1 is turned on by the first abnormal signal, and the IN1 and OUT1 terminals of the first analog switch IC1 are turned on, so that the first abnormal signal triggers the second switch tube V2 to turn on, the first switch tube V1 is turned off, and the first circuit breaker K1 loses power. After receiving the first abnormal signal, the IO3 terminal of the first controller U1 stops outputting the start signal. If the IO3 terminal of the first controller U1 does not receive the first abnormal signal within the set first timing time, it will output a pre-detection signal through the IO2 terminal of the first controller U1 within the second timing time, triggering the fourth switch tube V4 and the third switch tube V3 to turn on, and the B terminal of the first logic chip J1 becomes a high level. At this time, the fault threshold is reduced. If At this time, when the first voltage signal is greater than the fault threshold after the voltage is reduced, the first abnormal signal is output, the IN2 terminal and the OUT2 terminal of the first analog switch IC1 are turned on, so that the first logic chip J1 triggers the fifth switch tube V5 to turn on, and the third capacitor C3 stores energy. When the electric energy voltage stored in the third capacitor C3 in cooperation with the thirteenth resistor R13 and the fourteenth resistor R14 reaches the set voltage threshold, that is, when the turn-on voltage of the sixth switch tube V6 is reached, the sixth switch tube V6 is turned on, and the second switch tube V2 is controlled to turn on, the first circuit breaker K1 is connected to the mains, the charging gun is powered off, and the IO4 terminal of the first controller U1 receives and stops outputting the start signal.

[0061] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A safety protection circuit for a charging pile, characterized in that: The safety protection circuit of the charging pile includes: an intelligent control module, a charging pile module, a voltage sampling module, a mutation judgment module, an absolute value module, an abnormality judgment module, a gating control module and an abnormality detection module; The intelligent control module is connected to the strobe control module and the abnormality detection module, and is used to provide a start signal, set a first timing time and a second timing time, and when the first abnormality signal transmitted by the strobe control module is not received within the first timing time, the pre-detection signal is outputted regularly, and when the duration of outputting the pre-detection signal exceeds the second timing time, the pre-detection signal is stopped from being outputted, and when the first abnormality signal transmitted by the strobe control module is received or the second abnormality signal is outputted by the abnormality detection module, the start signal is stopped from being outputted; The charging pile module is connected to the intelligent control module, the gating control module and the abnormality detection module, and is used to receive the AC power and transmit the AC power to the charging gun when receiving the start signal, and stop receiving the start signal when receiving the first abnormal signal transmitted by the gating control module or the abnormality detection module outputs the second abnormal signal; The voltage sampling module is connected to the charging pile module and is used to perform isolation voltage sampling and signal amplification and filtering on the connected AC power and output a first sampling signal; The mutation judgment module is connected to the voltage sampling module, and is used to perform a 180-degree phase shift on the first sampling signal and detect the phase-shifted signal and perform superposition processing on the received first sampling signal, and output a first voltage signal; The absolute value module is connected to the mutation judgment module and is used to perform absolute value processing on the first voltage signal and output a second voltage signal; The abnormality judgment module is connected to the absolute value module, the intelligent control module and the mutation judgment module, and is used to set a fault threshold, output a first abnormality signal when the first voltage signal or the second voltage signal is greater than the fault threshold, and reduce the voltage value of the fault threshold when receiving a pre-detection signal; The gating control module is connected to the abnormality judgment module and is used to transmit the first abnormality signal to the intelligent control module and the charging pile module, and transmit the first abnormality signal to the abnormality detection module when receiving the pre-detection signal; The abnormality detection module is connected to the gating control module, and is used to store energy when receiving the first abnormality signal and the pre-detection signal transmitted by the gating control module, and output a second abnormality signal when the stored electric energy reaches a set voltage threshold.

2. The safety protection circuit of a charging pile according to claim 1, characterized in that: The charging pile module includes a charging pile power interface, a first circuit breaker, a first circuit breaker, a charging gun, a first power supply, a first switch tube and a second switch tube; the intelligent control module includes a first controller; The first end and the second end of the charging pile power interface are respectively connected to the first moving end and the second moving end of the first circuit breaker, the first static end and the second static end of the first circuit breaker are respectively connected to the first end and the second end of the charging gun, one end of the first circuit breaker is connected to the first power supply, the other end of the first circuit breaker is connected to the collector of the first switch tube, the emitter of the first switch tube and the emitter of the second switch tube are both grounded, the collector of the second switch tube is connected to the base of the first switch tube and the IO1 end of the first controller, and the base of the second switch tube is connected to the selection control module and the abnormality detection module.

3. The safety protection circuit of a charging pile according to claim 2, characterized in that: The voltage sampling module includes a first mutual inductor and a signal processing device; the mutation judgment module includes a first resistor, a second resistor, a first capacitor, a second capacitor, a seventh resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a first operational amplifier; The first end and the second end of the first mutual inductor are respectively connected to the first end and the second end of the charging pile power interface, the third end and the fourth end of the first mutual inductor are respectively connected to the first input end and the second input end of the signal processing device, the output end of the signal processing device is connected to the first end of the sixth resistor and is connected to one end of the seventh resistor and the inverting end of the first operational amplifier through the first resistor and the second capacitor in sequence, the in-phase end of the first operational amplifier is connected to one end of the third resistor and is connected to one end of the fifth resistor and the output end of the first operational amplifier through the fourth resistor, the other end of the fifth resistor is connected to the second end of the sixth resistor, the absolute value module and the abnormality judgment module, and the other end of the seventh resistor is connected to the ground end of the signal processing device, the other end of the third resistor and the ground end through the first capacitor and the second resistor in sequence.

4. The safety protection circuit of a charging pile according to claim 3, characterized in that: The abnormality judgment module includes a first comparator, a second comparator, a second power supply, a ninth resistor, an eighth resistor, a first potentiometer and a third switch tube; The non-inverting end of the second comparator is connected to the absolute value module, the inverting end of the first comparator is connected to the inverting end of the second comparator, one end of the eighth resistor and the collector of the third switch tube and is connected to the second power supply through the ninth resistor, the emitter of the third switch tube is connected to one end of the first potentiometer and the slider end, the non-inverting end of the first switch tube is connected to the second end of the sixth resistor, the other end of the eighth resistor is connected to the other end of the first potentiometer and the ground end, the base of the third switch tube is connected to the IO2 end of the first controller, and the output end of the first comparator is connected to the output end of the second comparator and the selection control module.

5. The safety protection circuit of a charging pile according to claim 4, characterized in that: The absolute value module includes an eleventh resistor, a twelfth resistor, a second operational amplifier, a third operational amplifier and a third diode; The inverting terminal of the second operational amplifier is connected to one end of the twelfth resistor and is connected to the second electric energy of the sixth resistor through the eleventh resistor, the output terminal of the second operational amplifier is connected to the anode of the third diode, the non-inverting terminal of the second operational amplifier is grounded, the cathode of the third diode is connected to the other end of the twelfth resistor and the non-inverting terminal of the third operational amplifier, and the inverting terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier and the non-inverting terminal of the second comparator.

6. The safety protection circuit of a charging pile according to claim 4, characterized in that: The gating control module includes a first analog switch, a third power supply, a tenth resistor, a fourth switch tube and a first diode; The IN1 and IN2 terminals of the first analog switch are both connected to the output terminal of the first comparator, the OUT1 terminal of the first analog switch is connected to the IO3 terminal of the first controller and the anode of the first diode, the cathode of the first diode is connected to the base of the second switch tube, the CTRL1 terminal of the first analog switch is connected to the collector of the fourth switch tube and is connected to the third power supply through the tenth resistor, the emitter of the fourth switch tube is grounded, the base of the fourth switch tube is connected to the CTRL2 terminal of the first analog switch and the IO2 terminal of the first controller, and the OUT2 terminal of the first analog switch is connected to the abnormality detection module.

7. A safety protection circuit for a charging pile according to claim 6, characterized in that: The abnormality detection module includes a fourth power supply, a first logic chip, a fifth switch tube, a thirteenth resistor, a third capacitor, a fourteenth resistor, a sixth switch tube, a fifteenth resistor and a second diode; The A end and the B end of the first logic chip are respectively connected to the OUT2 end of the first analog switch and the IO2 end of the first controller, the Y end of the first logic chip is connected to the base of the fifth switch tube, the collector of the fifth switch tube is connected to the fourth power supply and the collector of the sixth switch tube, the base of the sixth switch tube is connected to one end of the third capacitor, one end of the thirteenth resistor and the emitter of the fifth switch tube through the fourteenth resistor, the other end of the thirteenth resistor is connected to the other end of the third capacitor, one end of the fifteenth resistor and the ground, the emitter of the sixth switch tube is connected to the other end of the fifteenth resistor, the base of the second switch tube and the anode of the second diode, and the cathode of the second diode is connected to the IO4 end of the first controller.

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