Power supply control circuit and charging pile

Abstract

The present invention discloses a power supply control circuit and a charging pile, the power supply control circuit includes a signal sampling circuit, a first switch circuit, a second switch circuit and a main control circuit; the first switch circuit is arranged between the power grid connection end and the power supply output end; the second switch circuit is arranged between the ground connection end and the ground; the signal sampling circuit is connected to the power grid connection end and the main control circuit, and is used to collect power grid information and send the power grid information to the main control circuit; the main control circuit is connected to the first switch circuit and the second switch circuit, and is used to perform power supply anomaly detection according to the power grid information, obtain the anomaly detection result, and control the first switch circuit and / or the second switch circuit to work according to the anomaly detection result. The technical solution automatically and accurately identifies power supply anomalies, and can control the first switch circuit and / or the second switch circuit to disconnect when the power supply is abnormal, so as to ensure the safety of the power supply control circuit during operation.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a power supply control circuit and a charging pile. Background Art

[0002] With the rapid development of new energy vehicles, charging piles for new energy vehicles have been widely used, and the demand for charging piles is increasing. As equipment to provide energy supplement for new energy vehicles, charging piles have also been installed on a large scale. Therefore, the safety and reliability of charging piles are becoming more and more important.

[0003] However, the existing charging piles often have the phase line L and the neutral line N reversely connected during assembly or use; and the power supply system in some areas adopts the TN-CS system, which often causes the neutral line to be disconnected during charging, causing the charging pile shell or grounding terminal to be charged, resulting in electric shock safety accidents. Therefore, how to improve the safety of charging piles during use has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The embodiments of the present invention provide a power supply control circuit and a charging pile to solve the problem of poor safety during the use of existing charging piles.

[0005] A power supply control circuit comprises a signal sampling circuit, a first switch circuit, a second switch circuit and a main control circuit;

[0006] The first switch circuit is arranged between the grid connection terminal and the power supply output terminal;

[0007] The second switch circuit is arranged between the ground connection terminal and the ground;

[0008] The signal sampling circuit is connected to the grid connection terminal and the main control circuit, and is used to collect grid information and send the grid information to the main control circuit;

[0009] The main control circuit is connected to the first switch circuit and the second switch circuit, and is used to perform power supply anomaly detection according to the power grid information, obtain the anomaly detection result, and control the operation of the first switch circuit and / or the second switch circuit according to the anomaly detection result.

[0010] Furthermore, the grid connection terminal includes a phase line connection terminal and a neutral line connection terminal;

[0011] The signal sampling circuit includes a first voltage sampling circuit and a second voltage sampling circuit;

[0012] The first voltage sampling circuit is connected to the phase line connection terminal and is used to collect the phase line voltage;

[0013] The second voltage sampling circuit is connected to the neutral line connection end and is used for collecting the neutral line voltage.

[0014] Further, the first voltage sampling circuit includes a first voltage divider circuit and a first operational amplifier, wherein a first end of the first voltage divider circuit is connected to the phase line connection end, a second end of the first voltage divider circuit is grounded, a third end of the first voltage divider circuit is connected to a non-inverting input end of the first operational amplifier, an inverting input end of the first operational amplifier is used to connect a first reference voltage source, and an output end of the first operational amplifier is coupled to the main control circuit, and is used to output the phase line voltage with the main control circuit;

[0015] The second voltage sampling circuit includes a second voltage divider circuit and a second operational amplifier, the first end of the second voltage divider circuit is connected to the neutral line connection end, the second end of the second voltage divider circuit is grounded, the third end of the second voltage divider circuit is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is used to connect to a second reference voltage source, and the output end of the second operational amplifier is coupled to the main control circuit.

[0016] Furthermore, the main control circuit is used to:

[0017] Performing a positive and negative connection detection on the power grid according to the power grid information, and obtaining a positive and negative connection detection result;

[0018] If the forward and reverse connection detection result is forward connection, controlling the first switch circuit to be turned on;

[0019] If the forward and reverse connection detection result is reverse connection, the first switch circuit is controlled to be disconnected.

[0020] Further, the main control circuit is used to determine that the forward and reverse connection detection result is forward connection when the phase line voltage is greater than a first voltage threshold and the neutral line voltage is not less than the first voltage threshold;

[0021] When the phase line voltage is less than the first voltage threshold and the neutral line voltage is not greater than the first voltage threshold, it is determined that the forward and reverse connection detection result is reverse connection.

[0022] Furthermore, the main control circuit is used to:

[0023] Performing neutral line break detection according to the power grid information to obtain a first neutral line break detection result;

[0024] If the first disconnection detection result is that the neutral line is not disconnected, controlling the second switch circuit to be turned on;

[0025] If the first disconnection detection result is that the neutral line is disconnected, the second switch circuit is controlled to be disconnected.

[0026] Furthermore, the main control circuit is used to:

[0027] When the phase line voltage and the neutral line voltage are both within the second voltage threshold and the third voltage threshold, determining that the first line break detection result is that the neutral line is not broken;

[0028] When at least one of the phase line voltage and the neutral line voltage is less than the second voltage threshold or greater than a third voltage threshold, the first line break detection result is determined to be a neutral line break.

[0029] Furthermore, the main control circuit is used to:

[0030] Perform ground wire disconnection detection according to the power grid information to obtain a second ground wire disconnection detection result;

[0031] If the second disconnection detection result is that the ground line is not disconnected, controlling the first switch circuit and the second switch circuit to be turned on;

[0032] If the second disconnection detection result is that the ground line is disconnected, the first switch circuit and the second switch circuit are controlled to be disconnected.

[0033] Furthermore, the main control circuit is used to:

[0034] Comparing the phase line voltage and the neutral line voltage with a first voltage range respectively;

[0035] If at least one of the phase line voltage and the neutral line voltage is outside the first voltage range, the second disconnection detection result is that the ground line is disconnected;

[0036] If the phase line voltage and the neutral line voltage are both within the first voltage range, obtaining a first voltage fluctuation value of the phase line voltage within a first preset time and a second voltage fluctuation value of the neutral line voltage within the first preset time;

[0037] If the first voltage fluctuation value and the first voltage fluctuation value are both smaller than the preset fluctuation value, then the second disconnection detection result is that the grounding wire is not disconnected;

[0038] If the first voltage fluctuation value or at least one of the first voltage fluctuation values ​​is not less than a preset fluctuation value, the second disconnection detection result is that the ground wire is disconnected.

[0039] A charging pile comprises the above-mentioned power supply control circuit.

[0040] The above-mentioned power supply control circuit and charging pile, the power supply control circuit includes a signal sampling circuit, a first switch circuit, a second switch circuit and a main control circuit; the first switch circuit is arranged between the grid connection end and the power supply output end; the second switch circuit is arranged between the ground connection end and the ground; the signal sampling circuit is connected to the grid connection end and the main control circuit, and is used to collect grid information and send the grid information to the main control circuit; the main control circuit is connected to the first switch circuit and the second switch circuit, and is used to perform power supply anomaly detection according to the grid information, obtain the anomaly detection result, and control the first switch circuit and / or the second switch circuit to work according to the anomaly detection result, so as to automatically and accurately identify the power supply anomaly, and when the power supply is abnormal, it can control the first switch circuit and / or the second switch circuit to disconnect, so as to ensure the safety of the power supply control circuit during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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 labor.

[0042] Figure 1 is a circuit diagram of a power supply control circuit in one embodiment of the present invention;

[0043] Figure 2 is a circuit diagram of a signal sampling circuit in one embodiment of the present invention;

[0044] Figure 3 is a circuit diagram of a first switch circuit in one embodiment of the present invention;

[0045] Figure 4 FIG. 4 is a circuit diagram of a second switch circuit in an embodiment of the present invention.

[0046] In the figure: 1. signal sampling circuit; 11. first voltage sampling circuit; 111. first voltage divider circuit; 112. first operational amplifier; 12. second voltage sampling circuit; 121. second voltage divider circuit; 122. second operational amplifier; 2. first switch circuit; 3. second switch circuit; 4. main control circuit. DETAILED DESCRIPTION

[0047] 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 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.

[0048] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0049] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0050] The present embodiment provides a power supply control circuit, including a signal sampling circuit 1, a first switch circuit 2, a second switch circuit 3 and a main control circuit 4; the first switch circuit 2 is arranged between a grid connection terminal and a power supply output terminal; the second switch circuit 3 is arranged between a ground connection terminal and the ground; the signal sampling circuit 1 is connected to the grid connection terminal and the main control circuit 4, and is used to collect grid information and send the grid information to the main control circuit 4; the main control circuit 4 is connected to the first switch circuit 2 and the second switch circuit 3, and is used to perform power supply anomaly detection according to the grid information, obtain the anomaly detection result, and control the first switch circuit 2 and / or the second switch circuit 3 to work according to the anomaly detection result.

[0051] As an example, the power supply control circuit is applied in a charging pile, and the grid connection end is used to connect to the power supply grid. The power supply output end is used to connect a charging and discharging load or a power load. Exemplarily, the charging and discharging load is a load with charging and discharging functions. The charging and discharging load includes a new energy vehicle. The power load includes a household load. Exemplarily, the household load includes but is not limited to a mobile phone, a computer, an air conditioner, a refrigerator, and a television.

[0052] As an example, the first switch circuit 2 is provided between the grid connection terminal and the power supply output terminal, and is used to connect or disconnect the grid connection terminal and the power supply output terminal, so as to disconnect the power supply circuit when the power supply is abnormal. Exemplarily, the grid connection terminal is used to connect the phase line and the neutral line.

[0053] As an example, the second switch circuit 3 is provided between the ground connection terminal and the ground, and is used to connect or disconnect the ground connection terminal and the ground, so as to disconnect the ground loop when the power supply is abnormal. It should be noted that the ground connection terminal is used to connect the PE line.

[0054] As an example, the signal sampling circuit 1 is connected to the grid connection terminal and the main control circuit 4, and is used to collect grid information and send the grid information to the main control circuit 4. Optionally, the grid information includes phase line voltage and neutral line voltage.

[0055] As an example, the main control circuit 4 is connected to the first switch circuit 2 and the second switch circuit 3, and is used to perform power supply anomaly detection according to the power grid information, obtain the anomaly detection result, and control the first switch circuit 2 and / or the second switch circuit 3 to work according to the anomaly detection result. Optionally, the power supply anomaly detection includes power grid positive and reverse connection detection, neutral line break detection and ground line break detection. The anomaly detection result is the detection result obtained by performing power supply anomaly detection according to the power grid information. Exemplarily, when the charging pile is working, the first switch circuit 2 and the second switch circuit 3 of the power supply control circuit are normally turned on, the signal sampling circuit 1 collects the power grid information in real time, and sends the power grid information to the main control circuit 4, the main control circuit 4 automatically performs power supply anomaly detection, obtains the anomaly detection result, and controls the first switch circuit 2 and / or the second switch circuit 3 to work according to the anomaly detection result.

[0056] In this embodiment, the power supply control circuit includes a signal sampling circuit 1, a first switch circuit 2, a second switch circuit 3 and a main control circuit 4; the first switch circuit 2 is arranged between the grid connection end and the power supply output end; the second switch circuit 3 is arranged between the ground connection end and the ground; the signal sampling circuit 1 is connected to the grid connection end and the main control circuit 4, and is used to collect grid information and send the grid information to the main control circuit 4; the main control circuit 4 is connected to the first switch circuit 2 and the second switch circuit 3, and is used to perform power supply anomaly detection according to the grid information, obtain the anomaly detection result, and control the first switch circuit 2 and / or the second switch circuit 3 to work according to the anomaly detection result, so that when the power supply is abnormal, the first switch circuit 2 and / or the second switch circuit 3 can be controlled to be disconnected to ensure the safety of the power supply control circuit during operation.

[0057] In one embodiment, the grid connection terminal includes a phase line connection terminal L_IN_Power and a neutral line connection terminal N_IN_Power; the signal sampling circuit 1 includes a first voltage sampling circuit 11 and a second voltage sampling circuit 12; the first voltage sampling circuit 11 is connected to the phase line connection terminal L_IN_Power for collecting the phase line voltage; the second voltage sampling circuit 12 is connected to the neutral line connection terminal N_IN_Power for collecting the neutral line voltage.

[0058] In this embodiment, the first voltage sampling circuit 11 is connected to the phase line connection terminal L_IN_Power for collecting the phase line voltage; the second voltage sampling circuit 12 is connected to the neutral line connection terminal N_IN_Power for collecting the neutral line voltage, so as to perform power supply anomaly detection based on the phase line voltage and the neutral line voltage to ensure the accuracy of power supply anomaly detection.

[0059] In one embodiment, the first voltage sampling circuit 11 includes a first voltage divider circuit 111 and a first operational amplifier 112 (U1A), wherein a first end of the first voltage divider circuit 111 is connected to a phase line connection end L_IN_Power, a second end of the first voltage divider circuit 111 is grounded, a third end of the first voltage divider circuit 111 is connected to a non-inverting input end of the first operational amplifier 112, an inverting input end of the first operational amplifier 112 is used to connect a first reference voltage source, and an output end of the first operational amplifier 112 is coupled to a main control circuit 4, and is used to output a phase line voltage with the main control circuit 4; the second voltage sampling circuit 12 includes a second voltage divider circuit 121 and a second operational amplifier 122 (U1B), wherein a first end of the second voltage divider circuit 121 is connected to a neutral line connection end N_IN_Power, a second end of the second voltage divider circuit 121 is grounded, a third end of the second voltage divider circuit 121 is connected to a non-inverting input end of the second operational amplifier 122, an inverting input end of the second operational amplifier 122 is used to connect a second reference voltage source, and an output end of the second operational amplifier 122 is coupled to the main control circuit 4.

[0060] The first reference voltage source and the second reference voltage source may be the same reference voltage source, or may be different reference voltage sources. Exemplarily, the first reference voltage source and the second reference voltage source are 1.65 volt reference voltage sources.

[0061] As an example, the first voltage divider circuit 111 includes a first voltage divider resistor R1 and a second voltage divider resistor R6, the first voltage divider resistor R1 and the second voltage divider resistor R6 are arranged in series between the first end of the first voltage divider circuit 111 and the second end of the first voltage divider circuit 111, and the connection node between the first voltage divider resistor R1 and the second voltage divider resistor R6 is connected to the third end of the first voltage divider circuit 111. Further, a first capacitor circuit and a first resistor circuit connected in series are also provided between the first end of the first voltage divider circuit 111 and the phase line connection terminal L_IN_Power for input filtering. Exemplarily, the first capacitor circuit includes a capacitor C1 and a capacitor C2 connected in series, and the first resistor circuit includes a resistor R3, a resistor R4 and a resistor R5 connected in series. Further, the first voltage sampling circuit 11 also includes a first lightning protection circuit, the first end of the first lightning protection circuit is connected to the phase line connection terminal L_IN_Power, and the second end of the first lightning protection circuit is grounded. Exemplarily, the first lightning protection circuit includes a resistor RV1 and a discharge tube G1 arranged in series. Exemplarily, the first voltage sampling circuit 11 also includes a voltage stabilizing capacitor C3, the first end of which is connected to the in-phase input terminal of the first operational amplifier 112, and the second end of which is grounded. Further, the first voltage sampling circuit 11 also includes a first voltage follower circuit, the first end of which is connected to the reverse input terminal of the first operational amplifier 112, and the second end of which is connected to the output terminal of the first operational amplifier 112. Exemplarily, the first voltage follower circuit includes a resistor R7 and a capacitor C4 arranged in parallel. Exemplarily, the first reference voltage source is connected to the reverse input terminal of the first operational amplifier 112 through a resistor R8, and the output terminal of the first operational amplifier 112 is connected to the first detection terminal L_IN_MCU of the main control circuit 4 through a resistor R2. Further, the first voltage sampling circuit 11 also includes a first bidirectional diode D1, the first end of which is used to connect the power supply voltage CP3.3V, the second end of the first bidirectional diode is grounded, and the third end of the first bidirectional diode is connected to the output terminal of the first operational amplifier 112, for protecting the main control circuit 4.

[0062] As an example, the second voltage divider circuit 121 includes a third voltage divider resistor R9 and a fourth voltage divider resistor R15, the third voltage divider resistor R9 and the fourth voltage divider resistor R15 are arranged in series between the first end of the second voltage divider circuit 121 and the second end of the second voltage divider circuit 121, and the connection node between the third voltage divider resistor R9 and the fourth voltage divider resistor R15 is connected to the third end of the second voltage divider circuit 121. Further, a second capacitor circuit and a second resistor circuit connected in series are also provided between the first end of the second voltage divider circuit 121 and the neutral line connection terminal N_IN_Power for input filtering. Exemplarily, the second capacitor circuit includes a capacitor C5 and a capacitor C6 connected in series, and the second resistor circuit includes a resistor R12, a resistor R13 and a resistor R14 connected in series. Further, the second voltage sampling circuit 12 also includes a second lightning protection circuit, the first end of the second lightning protection circuit is connected to the neutral line connection terminal N_IN_Power, and the second end of the second lightning protection circuit is grounded. Exemplarily, the second lightning protection circuit includes a resistor RV2 and a discharge tube G2 arranged in series. Exemplarily, the second voltage sampling circuit 12 also includes a voltage-stabilizing capacitor C7, a first end of which is connected to the in-phase input terminal of the second operational amplifier 122, and a second end of which is grounded. Further, the second voltage sampling circuit 12 also includes a second voltage follower circuit, a first end of which is connected to the reverse input terminal of the second operational amplifier 122, and a second end of which is connected to the output terminal of the second operational amplifier 122. Exemplarily, the second voltage follower circuit includes a resistor R17 and a capacitor C8 arranged in parallel. Exemplarily, the second reference voltage source is connected to the reverse input terminal of the second operational amplifier 122 through a resistor R18, and the output terminal of the second operational amplifier 122 is connected to the second detection terminal N_IN_MCU of the main control circuit 4 through a resistor R10. Further, the second voltage sampling circuit 12 also includes a second bidirectional diode D2, a first end of which is used to connect the power supply voltage CP3.3V, a second end of the second bidirectional diode is grounded, and a third end of the second bidirectional diode is connected to the output terminal of the second operational amplifier 122, for protecting the main control circuit 4.

[0063] In one embodiment, the main control circuit 4 is used to perform positive and reverse connection detection of the power grid according to the power grid information and obtain the positive and reverse connection detection result; if the positive and reverse connection detection result is positive connection, the first switch circuit 2 is controlled to be turned on; if the positive and reverse connection detection result is reverse connection, the first switch circuit 2 is controlled to be turned off.

[0064] As an example, the first end of the first switch circuit 2 is connected to the phase line connection terminal L_IN_Power, the second end of the first switch circuit 2 is connected to the neutral line connection terminal N_IN_Power, the third end of the first switch circuit 2 is the phase line output terminal L_OUT_Power, and the fourth end of the first switch circuit 2 is the neutral line output terminal N_OUT_Power. In this example, when the positive and negative connection detection result is positive connection, that is, the first end of the first switch circuit 2 is connected to the phase line of the power supply grid through the phase line connection terminal L_IN_Power, and the first end of the second switch circuit 3 is connected to the neutral line of the power supply grid through the neutral line connection terminal N_IN_Power. When the positive and negative connection detection result is positive connection, that is, the first end of the first switch circuit 2 is connected to the neutral line of the power supply grid through the phase line connection terminal L_IN_Power, and the first end of the second switch circuit 3 is connected to the phase line of the power supply grid through the neutral line connection terminal N_IN_Power. The main control circuit 4 is used to perform positive and reverse connection detection of the power grid according to the power grid information, and obtain the positive and reverse connection detection result to determine whether the power supply grid is reversely connected. When the power supply grid is positively connected, the first switch circuit 2 is controlled to be turned on so that the power supply grid can supply power normally. When the power supply grid is positively connected, the first switch circuit 2 is controlled to be turned off to disconnect the power supply grid, thereby automatically realizing the positive and reverse connection detection of the power supply grid. When the power supply grid is reversely connected, the power supply grid is disconnected to ensure the safety of the user.

[0065] Further, the first switch circuit 2 may include a double-pole single-throw relay RL1, or two single-pole single-throw relays RL2. In this example, the first switch circuit 2 includes a double-pole single-throw relay RL1 and a first transistor. Exemplarily, the first moving contact of the double-pole single-throw relay RL1 is connected to the phase line connection terminal L_IN_Power, the second moving contact of the double-pole single-throw relay RL1 is connected to the neutral line connection terminal N_IN_Power, the first static contact of the double-pole single-throw relay RL1 is the phase line output terminal, and the second static contact of the double-pole single-throw relay RL1 is the neutral line output terminal. The first moving contact and the first static contact are normally closed contacts, and the second moving contact and the second static contact are normally closed contacts. One end of the coil of the double-pole single-throw relay RL1 is connected to the power supply VCC+5V, the other end is connected to the first end of the first transistor, the second end of the first transistor is grounded, and the third end of the first transistor is connected to the control end Relay_Col_02 of the main control circuit 4. Further, a resistor R11 and a resistor R16 are connected in series between the control terminal Relay_Col_02 of the main control circuit 4 and the ground DGND, and the connection node between the resistor R11 and the resistor R16 is connected to the third end of the first transistor. The first end of the first transistor is connected to the power supply VCC+5V through a diode D2, and the diode D2 is used to protect the first transistor. Exemplarily, the first transistor can be a bipolar transistor or a field effect transistor. The first end of the first transistor is a collector or a source, the second end of the first transistor is an emitter or a drain, and the third end of the first transistor is a base or a gate. In this example, when the control terminal Relay_Col_02 of the main control circuit 4 outputs a low-level control signal, the first transistor is disconnected, the coil of the double-pole single-throw relay RL1 is not energized, and the double-pole single-throw relay RL1 is turned on. When the control terminal Relay_Col_02 of the main control circuit 4 outputs a high-level control signal, the first transistor is turned on, the coil of the double-pole single-throw relay RL1 is energized, and the double-pole single-throw relay RL1 is disconnected.

[0066] In one embodiment, the main control circuit 4 is used to determine that the forward and reverse connection detection result is forward connection when the phase line voltage is greater than the first voltage threshold and the neutral line voltage is not less than the first voltage threshold; and to determine that the forward and reverse connection detection result is reverse connection when the phase line voltage is less than the first voltage threshold and the neutral line voltage is not greater than the first voltage threshold.

[0067] The first voltage threshold is a custom-set threshold, for example, in this example, the first voltage threshold is 32V.

[0068] As an example, when the main control circuit 4 determines that the phase line voltage is greater than 32V and the neutral line voltage is not less than 32V, it determines that the forward and reverse connection detection result is forward connection. When the main control circuit 4 determines that the phase line voltage is less than 32V and the neutral line voltage is not greater than 32V, it determines that the forward and reverse connection detection result is forward connection, thereby realizing the forward and reverse connection detection of the power supply network. Further, a first holding time can also be set to judge whether the holding time of the phase line voltage being greater than the first voltage threshold and the neutral line voltage being not less than the first voltage threshold, or the phase line voltage being less than the first voltage threshold and the neutral line voltage being not greater than the first voltage threshold is greater than the first holding time. If it is greater than the first holding time, the corresponding forward and reverse connection detection result is obtained to improve the fault tolerance of the forward and reverse connection detection result.

[0069] In one embodiment, the main control circuit 4 is used to perform neutral line break detection according to the power grid information and obtain a first break detection result; if the first break detection result is that the neutral line is not broken, the second switch circuit 3 is controlled to be turned on; if the first break detection result is that the neutral line is broken, the second switch circuit 3 is controlled to be turned off.

[0070] As an example, the second switch circuit 3 includes a single-pole single-throw relay RL2 and a second transistor. The third moving contact and the third static contact of the single-pole single-throw relay RL2 are arranged between the ground connection terminal PE_IN_Power and the ground DGND (PE_OUT_Power), one end of the coil of the single-pole single-throw relay RL2 is connected to the power supply VCC+5V, and the other end is connected to the first end of the second transistor, the second end of the second transistor is grounded, and the third end of the second transistor is connected to the control end Relay_Col_01 of the main control circuit 4. The first end of the second transistor is connected to the power supply VCC+5V through a diode D4, and the diode D4 is used to protect the second transistor. Further, resistors R22 and R23 are connected in series between the control end Relay_Col_01 of the main control circuit 4 and the ground DGND, and the connection node between the resistors R22 and R23 is connected to the third end of the second transistor. Exemplarily, the second transistor can be a bipolar transistor or a field effect transistor. The first end of the second transistor is a collector or source, the second end of the second transistor is an emitter or drain, and the third end of the second transistor is a base or gate. In this example, when the control end Relay_Col_01 of the main control circuit 4 outputs a low-level control signal, the second transistor is disconnected, the coil of the single-pole single-throw relay RL2 is not energized, and the single-pole single-throw relay RL2 is turned on. When the control end Relay_Col_01 of the main control circuit 4 outputs a high-level control signal, the second transistor is turned on, the coil of the single-pole single-throw relay RL2 is energized, and the single-pole single-throw relay RL2 is disconnected.

[0071] In this embodiment, the main control circuit 4 is used to perform neutral line break detection according to the power grid information and obtain a first break detection result; if the first break detection result is that the neutral line is not broken, the second switch circuit 3 is controlled to be turned on; if the first break detection result is that the neutral line is broken, the second switch circuit 3 is controlled to be disconnected, thereby realizing neutral line break detection and corresponding neutral line break protection, thereby improving safety.

[0072] In one embodiment, the main control circuit 4 is used to, when the phase line voltage and the neutral line voltage are both within the second voltage threshold and the third voltage threshold, determine that the first line break detection result is that the neutral line is not broken; when at least one of the phase line voltage and the neutral line voltage is less than the second voltage threshold, or greater than the third voltage threshold, determine that the first line break detection result is that the neutral line is broken.

[0073] The second voltage threshold is less than the third voltage threshold. Exemplarily, the second voltage threshold is 207V and the third voltage threshold is 253V.

[0074] In this embodiment, when the phase line voltage and the neutral line voltage are both within the range of 207V to 253V, it is determined that the neutral line is not disconnected, power can be supplied normally, and the second switch circuit 3 is controlled to be turned on. When at least one of the phase line voltage and the neutral line voltage is less than 207V or greater than 253V, it is determined that the neutral line is disconnected, power supply is stopped, and the second switch circuit 3 is controlled to be disconnected to prevent electric shock and improve circuit safety. Further, a second holding time can also be set to judge whether the holding time of the phase line voltage and the neutral line voltage, both within the second voltage threshold and the third voltage threshold, or the holding time of at least one of the phase line voltage and the neutral line voltage, less than the second voltage threshold, or greater than the third voltage threshold, is greater than the second holding time. If it is greater than the second holding time, the corresponding first disconnection detection result is obtained to improve the fault tolerance of the first disconnection detection result. The first holding time and the second holding time can be the same or different, and can be set according to actual experience, and are not limited here.

[0075] In one embodiment, the main control circuit 4 is used to perform ground wire break detection based on power grid information and obtain a second break detection result; if the second break detection result is that the ground wire is not broken, the first switch circuit 2 and the second switch circuit 3 are controlled to be turned on; if the second break detection result is that the ground wire is broken, the first switch circuit 2 and the second switch circuit 3 are controlled to be disconnected.

[0076] In this embodiment, when the main control circuit 4 performs ground wire break detection according to the power grid information and obtains the second break detection result, and determines that the second break detection result is that the ground wire is not broken, the first switch circuit 2 and the second switch circuit 3 are controlled to be turned on to enable the power supply grid to supply power normally; when it is determined that the second break detection result is that the ground wire is broken, the first switch circuit 2 and the second switch circuit 3 are controlled to be disconnected, thereby realizing ground wire break detection and ground wire break protection, thereby improving the safety line of the circuit.

[0077] In one embodiment, the main control circuit 4 is used to compare the phase line voltage and the neutral line voltage with the first voltage range respectively; if at least one of the phase line voltage and the neutral line voltage is outside the first voltage range, the second line break detection result is that the ground line is broken; if the phase line voltage and the neutral line voltage are both within the first voltage range, the first voltage fluctuation value of the phase line voltage within the first preset time and the second voltage fluctuation value of the neutral line voltage within the first preset time are obtained; if the first voltage fluctuation value and the first voltage fluctuation value are both less than the preset fluctuation value, the second line break detection result is that the ground line is not broken; if the first voltage fluctuation value or at least one of the first voltage fluctuation values ​​is not less than the preset fluctuation value, the second line break detection result is that the ground line is broken.

[0078] The first voltage range is a user-defined range. Preferably, the first voltage range is 85V to 264V.

[0079] In this embodiment, since the phase line voltage and the neutral line voltage will fluctuate irregularly within a certain voltage range when the ground wire is broken, the phase line voltage and the neutral line voltage are compared with the first voltage range respectively; if at least one of the phase line voltage and the neutral line voltage is outside the first voltage range, the second break detection result is that the ground wire is broken; if the phase line voltage and the neutral line voltage are both within the first voltage range, the first voltage fluctuation value of the phase line voltage within the first preset time and the second voltage fluctuation value of the neutral line voltage within the first preset time are obtained; if the first voltage fluctuation value and the first voltage fluctuation value are both less than the preset fluctuation value, the second break detection result is that the ground wire is not broken; if the first voltage fluctuation value or at least one of the first voltage fluctuation values ​​is not less than the preset fluctuation value, the second break detection result is that the ground wire is broken, and the ground wire break detection can be accurately realized.

[0080] This embodiment provides a charging pile, including the above-mentioned power supply control circuit.

[0081] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A power supply control circuit, characterized in that: It includes a signal sampling circuit, a first switch circuit, a second switch circuit and a main control circuit; The first switch circuit is arranged between the grid connection terminal and the power supply output terminal; The second switch circuit is arranged between the ground connection terminal and the ground; The signal sampling circuit is connected to the grid connection terminal and the main control circuit, and is used to collect grid information and send the grid information to the main control circuit; The main control circuit is connected to the first switch circuit and the second switch circuit, and is used to perform power supply anomaly detection according to the power grid information, obtain anomaly detection results, and control the operation of the first switch circuit and / or the second switch circuit according to the anomaly detection results; the power supply anomaly detection includes power grid positive and reverse connection detection, neutral line disconnection detection, and ground line disconnection detection; The grid connection terminal includes a phase line connection terminal and a neutral line connection terminal; The signal sampling circuit includes a first voltage sampling circuit and a second voltage sampling circuit; The first voltage sampling circuit is connected to the phase line connection terminal and is used to collect the phase line voltage; The second voltage sampling circuit is connected to the neutral line connection end and is used to collect the neutral line voltage; Wherein, the main control circuit is used for: Performing neutral line break detection according to the power grid information to obtain a first neutral line break detection result; If the first disconnection detection result is that the neutral line is not disconnected, controlling the second switch circuit to be turned on; If the first disconnection detection result is that the neutral line is disconnected, controlling the second switch circuit to be disconnected; Wherein, the main control circuit is used for: When the phase line voltage and the neutral line voltage are both within the second voltage threshold and the third voltage threshold, determining that the first line break detection result is that the neutral line is not broken; When at least one of the phase line voltage and the neutral line voltage is less than the second voltage threshold or greater than a third voltage threshold, the first line break detection result is determined to be a neutral line break.

2. The power supply control circuit according to claim 1, characterized in that: The first voltage sampling circuit comprises a first voltage divider circuit and a first operational amplifier, wherein a first end of the first voltage divider circuit is connected to the phase line connection end, a second end of the first voltage divider circuit is grounded, a third end of the first voltage divider circuit is connected to the in-phase input end of the first operational amplifier, an inverting input end of the first operational amplifier is used to connect a first reference voltage source, and an output end of the first operational amplifier is coupled to the main control circuit for outputting the phase line voltage with the main control circuit; The second voltage sampling circuit includes a second voltage divider circuit and a second operational amplifier, the first end of the second voltage divider circuit is connected to the neutral line connection end, the second end of the second voltage divider circuit is grounded, the third end of the second voltage divider circuit is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is used to connect to a second reference voltage source, and the output end of the second operational amplifier is coupled to the main control circuit.

3. The power supply control circuit according to claim 1, characterized in that: The main control circuit is used to: Performing a positive and negative connection detection on the power grid according to the power grid information, and obtaining a positive and negative connection detection result; If the forward and reverse connection detection result is forward connection, controlling the first switch circuit to be turned on; If the forward and reverse connection detection result is reverse connection, the first switch circuit is controlled to be disconnected.

4. The power supply control circuit according to claim 3, characterized in that: The main control circuit is used to determine that the forward and reverse connection detection result is forward connection when the phase line voltage is greater than a first voltage threshold and the neutral line voltage is not less than the first voltage threshold; When the phase line voltage is less than the first voltage threshold and the neutral line voltage is not greater than the first voltage threshold, it is determined that the forward and reverse connection detection result is reverse connection.

5. The power supply control circuit according to claim 1, characterized in that: The main control circuit is used to: Perform ground wire disconnection detection according to the power grid information to obtain a second ground wire disconnection detection result; If the second disconnection detection result is that the ground line is not disconnected, controlling the first switch circuit and the second switch circuit to be turned on; If the second disconnection detection result is that the ground line is disconnected, the first switch circuit and the second switch circuit are controlled to be disconnected.

6. The power supply control circuit according to claim 5, characterized in that: The main control circuit is used to: Comparing the phase line voltage and the neutral line voltage with a first voltage range respectively; If at least one of the phase line voltage and the neutral line voltage is outside the first voltage range, the second disconnection detection result is that the ground line is disconnected; If the phase line voltage and the neutral line voltage are both within the first voltage range, obtaining a first voltage fluctuation value of the phase line voltage within a first preset time and a second voltage fluctuation value of the neutral line voltage within the first preset time; If the first voltage fluctuation value and the second voltage fluctuation value are both smaller than the preset fluctuation value, the second disconnection detection result is that the grounding wire is not disconnected; If at least one of the first voltage fluctuation value or the second voltage fluctuation value is not less than the preset fluctuation value, the second disconnection detection result is that the ground wire is disconnected.

7. A charging pile, characterized in that: Comprising the power supply control circuit as described in any one of claims 1 to 6.

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