Implementation method of metering monitoring line of charging pile cluster

Abstract

The invention relates to the technical field of charging pile metering, in particular to an implementation method of a metering monitoring circuit of a charging pile cluster. A first metering module is originally connected with a first charging gun in series through a first zero line to form a charging metering loop; the first metering module is connected to a second zero line where an adjacent second metering module is located through a wire; a first lead is led out from the second zero line and is connected with the first charging gun to form a charging metering loop of the first charging gun; and a first public electric energy sensor is connected in series on the second null line and between a node of the first metering module connected to the second null line and a node of a first lead led out from the second null line, so that a first-stage monitoring line is established, and a monitoring line in a whole charging pile cluster is established according to a mode of establishing the first-stage monitoring line. Therefore, the large-scale monitoring of the metering error of each metering module is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of charging pile metering, and particularly to a method for implementing a metering and monitoring circuit of a charging pile cluster. Background Art

[0002] A charging pile is a metering device for charging electricity transactions. To ensure the fairness and justice of transactions, it is necessary to implement electricity metering supervision on charging piles. In addition to the mandatory error verification stipulated by national metrology laws, regulations and verification procedures, there is also an urgent need in the market to monitor the metering errors of metering modules in operating charging piles. Existing methods for monitoring the metering errors of metering modules cannot achieve large-scale monitoring.

[0003] In view of this, overcoming the defects of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is:

[0005] When monitoring the metering error of the metering module in the existing charging pile, large-scale monitoring cannot be achieved, so the efficiency of monitoring the metering error of the metering module will be greatly reduced.

[0006] In a first aspect, the present invention provides a method for implementing a metering and monitoring circuit of a charging pile cluster. The metering modules of each charging pile are connected in series on the neutral line of the corresponding charging line. The implementation method includes:

[0007] Changing the design in which the first metering module is originally connected in series with the first charging gun through the first neutral line to form a charging metering circuit, so that the first metering module is connected to the second neutral line where the adjacent second metering module is located through a wire; after leading out a first wire on the second neutral line and connecting it to the first charging gun, a charging metering circuit for the first charging gun is formed;

[0008] A first common power sensor is connected in series on the second neutral line between the node where the first metering module is connected to the second neutral line and the node of the first wire led out on the second neutral line, thereby building a first-level monitoring circuit;

[0009] According to the method of building the first-level monitoring circuit for the first charging gun and the second charging gun, build the second-level monitoring circuit relationship between the original second metering module, the second charging gun, the third metering module, the third neutral line and the second common power sensor, until the charging metering circuit of the originally last charging gun in the entire charging pile cluster is adjusted, thereby building the monitoring circuit in the entire charging pile cluster.

[0010] Preferably, a first common power sensor is connected in series between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line on the second neutral line. The system further includes:

[0011] The second metering module is located on the second neutral line other than between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line.

[0012] Preferably, when performing error detection, the method further includes:

[0013] A power metering standard device is connected in series to the charging metering circuit of the first charging gun, and through the charging operation of the corresponding first charging gun, the metering error of the first metering module and / or the metering error of the first common power sensor are detected;

[0014] Based on the metering error of the first common power sensor, the first common power sensor is calibrated, and through the calibrated first common power sensor, during the charging operation of the corresponding second charging gun, the metering error of the second metering module and / or the metering error of the second common power sensor are detected.

[0015] Preferably, the step of connecting a power metering standard device in series to the charging metering circuit of the first charging gun and detecting the metering error of the first metering module and / or the metering error of the first common power sensor through the charging operation of the corresponding first charging gun specifically includes:

[0016] When the power metering standard device is connected in series between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line and is adjacent to the first common power sensor, through the charging operation of the corresponding first charging gun and / or the second charging gun, the metering error of the first common power sensor is detected; and further when it is confirmed that the first charging gun is working and the second charging gun is in an idle state, the metering error of the first metering module is detected by using the first common power sensor or the power metering standard device after calibration of the metering error.

[0017] Preferably, the step of connecting a power metering standard device in series to the charging metering circuit of the first charging gun and detecting the metering error of the first metering module and / or the metering error of the first common power sensor through the charging operation of the corresponding first charging gun further specifically includes:

[0018] When the power metering standard device is connected in series to the first neutral line and not on the second neutral line, through the charging operation of the corresponding first charging gun, the metering error of the first metering module is detected; and further when it is confirmed that the first charging gun is working and the second charging gun is in an idle state, the metering error of the first common power sensor is detected by using the first metering module or the power metering standard device after calibration of the metering error.

[0019] Preferably, it further includes an electric energy data collector and a computing system;

[0020] The electric energy data collector is used to collect the measurement values of the metering modules, public electric energy sensors, and electric energy metering standards in each charging pile and transmit them to the computing system;

[0021] The computing system is used to calculate the metering errors of the metering module and / or the public electric energy sensor.

[0022] Preferably, it further includes a detection load;

[0023] The detection load includes the power battery of an electric vehicle as an actual load for detection, a specially designed equivalent load, or a virtual load simulated by independent current sources and voltage sources.

[0024] Preferably, the monitoring line is permanently fixed and held, or the monitoring line is temporarily set up.

[0025] Preferably, the implementation method further includes:

[0026] A toggle switch or a wireless transmitter is provided in the charging gun of each charging pile;

[0027] Wherein, the toggle switch is in a closed state when the charging gun is working, so as to trigger the switch between the metering module and the AC / DC converter of the charging pile to be in a closed state; it is also in an open state when the charging gun is idle, so as to trigger the switch between the metering module and the AC / DC converter of the charging pile to be in an open state.

[0028] Preferably, the implementation method further includes:

[0029] A wireless transmitter is provided in the charging gun of each charging pile;

[0030] Wherein, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch between the metering module and the AC / DC converter of the charging pile to be in a closed state; it is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch between the metering module and the AC / DC converter of the charging pile to be in an open state.

[0031] In a second aspect, the present invention provides a method for detecting the metering error of electric energy with interconnected charging metering lines, including:

[0032] Each charging metering line is provided with its own electric energy sensor; every two adjacent charging metering lines are interconnected through a common electric energy sensor to form an interconnected structure of the electric energy metering error detection line;

[0033] By performing time-sharing charging on every two adjacent charging metering lines, the errors between their respective power sensors and the common power sensor are obtained to achieve the transfer measurement and calculation of the power metering errors between the charging metering lines.

[0034] Preferably, for every two adjacent charging metering lines, taking one as the first charging metering line and the other as the second charging metering line, then the time-sharing charging of every two adjacent charging metering lines and obtaining the errors between their respective power sensors and the common power sensor specifically include:

[0035] When the first charging metering line is charging, the electrical energy of the first charging metering line flows through the power sensor of the first charging metering line and the common power sensor to obtain the first power metering error of the power sensor of the first charging metering line relative to the common power sensor;

[0036] When the second charging metering line is charging, the electrical energy of the second charging metering line flows through the power sensor of the second charging metering line and the common power sensor to obtain the second power metering error of the power sensor of the second charging metering line relative to the common power sensor.

[0037] Preferably, the realization of the transfer measurement and calculation of the power metering errors between the charging metering lines specifically includes:

[0038] The third power metering error of the power sensor of the first charging metering line relative to the power sensor of the second charging metering line, that is, the power metering error between two adjacent charging metering lines, is obtained through the first power metering error and the second power metering error, and so on, to achieve the transfer measurement and calculation of the power metering errors between all charging metering lines.

[0039] Preferably, when the errors of the power sensor of the first charging metering line or the power sensor of the second charging metering line relative to the standard power sensor are both uncertain, the power metering error between the two power sensors is the difference between their true errors; when the error of one of the power sensor of the first charging metering line, the power sensor of the second charging metering line, and the common power sensor relative to the standard power sensor is determined, the errors of the remaining two power sensors are the true errors.

[0040] Preferably, the specific inclusion of each charging metering line being provided with its own power sensor is: the power sensor of each charging metering line is provided on the neutral line side of its own charging metering line.

[0041] Preferably, the specific connection of every two adjacent charging metering lines through a common power sensor includes: the neutral lines of every two adjacent charging metering lines equipped with power sensors commonly pass through the same common power sensor.

[0042] Preferably, the common power sensor between two adjacent charging metering lines is a DC current transformer.

[0043] Preferably, for two adjacent charging metering lines, when one charging metering line is charging alone, the other charging metering line is in a power-off and deactivated state, and when each charging metering line is charging, the common power sensor connected to it and its own power sensor are connected to the same voltage signal.

[0044] Preferably, a controllable switch is provided on each charging metering line to disconnect the connection of its own charging metering line when its adjacent charging metering line is charging, so that its own charging metering line is in a power-off and deactivated state.

[0045] Preferably, the power sensor on each charging metering line is one or more, specifically including one or more of the power sensors for billing settlement, the power sensors for error detection, and the power sensors for other purposes.

[0046] In a third aspect, an embodiment of the present invention provides an electric energy error detection method based on virtual quantity interconnection. The common power sensors of adjacent charging piles form a measurement system through their respective charging lines and satisfy the virtual electric energy conservation relationship. Moreover, the power sensors of each charging pile are connected in series on the neutral line of the corresponding charging line. The detection method includes:

[0047] Select two adjacent first charging pile and second charging pile. A first power sensor is provided on the charging line of the first charging pile, a second power sensor is provided on the charging line of the second charging pile, and moreover, the charging lines of the first charging pile and the second charging pile both pass through a third power sensor, forming an interconnection structure for electric energy error detection;

[0048] Install a standard power sensor on the charging line of the first charging pile, use the standard power sensor to calibrate the first power sensor and the third power sensor on the first charging pile, and obtain the absolute errors of the first power sensor and the third power sensor respectively;

[0049] Establish a virtual quantity interconnection electric energy conservation relationship model, and obtain the relationship function of the true electric energy values of the first power sensor, the second power sensor, and the third power sensor; use the calibrated electric energy measurement values of the first power sensor and the third power sensor, and the relationship function of the true electric energy values, to obtain the true value and absolute error of the second power sensor, and finally complete the calibration of the second power sensor.

[0050] Preferably, to achieve the detection of the electrical energy for the virtual quantity interconnection of all charging piles, after calibrating the second electrical energy sensor, it further includes calibrating the electrical energy sensors of the charging piles other than the first charging pile and the second charging pile. The specific calibration includes:

[0051] Taking the calibrated second electrical energy sensor or the third electrical energy sensor as the standard meter, calibrating the common electrical energy sensor of the charging pile adjacent to the second charging pile by using the series connection relationship, and obtaining the absolute error of the common electrical energy sensor;

[0052] Calibrating the electrical energy sensor of the charging pile itself adjacent to the second charging pile by using the virtual quantity interconnection electrical energy conservation relationship model and the series connection relationship, and obtaining the absolute error of the electrical energy sensor of the charging pile itself;

[0053] Then, taking the calibrated electrical energy sensor of the adjacent charging pile as the standard meter, sequentially detecting and calibrating the electrical energy sensors in the subsequent charging piles until all the electrical energy sensors in the charging piles are calibrated.

[0054] Preferably, the first charging pile and the second charging pile share the third electrical energy sensor, and the neutral lines of the charging lines of the first charging pile and the second charging pile respectively pass through the third electrical energy sensor.

[0055] Preferably, the operation of calibrating the first electrical energy sensor and the third electrical energy sensor on the first charging pile by using the standard electrical energy sensor is as follows:

[0056] Connect the charging gun of the first charging pile to make the charging line of the first charging pile in a conducting state. Keep the charging guns on the charging piles other than the first charging pile in a vacant state, and the switch located between the electrical energy sensor and the AC / DC converter of the charging pile is in a closed state;

[0057] Utilize the series connection relationship among the first electrical energy sensor, the third electrical energy sensor, and the standard electrical energy sensor in the conducting state to calibrate the first electrical energy sensor and the third electrical energy sensor.

[0058] Preferably, at least one electrical energy sensor is provided on each charging pile for the charging fee settlement of the charging pile.

[0059] Preferably, the absolute error represents the absolute value of the difference between the measured value and the true value of each electrical energy sensor.

[0060] Preferably, the detection method further includes:

[0061] A toggle switch or a wireless transmitter is provided in the charging gun of each charging pile;

[0062] Wherein, the toggle switch is used to be in a closed state when the charging gun is working, so as to trigger the switch located between the power sensor and the AC-DC converter of the charging pile to be in a closed state; and is also used to be in an open state when the charging gun is idle, so as to trigger the switch located between the power sensor and the AC-DC converter of the charging pile to be in an open state.

[0063] Wherein, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch located between the power sensor and the AC-DC converter of the charging pile to be in a closed state; and is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch located between the power sensor and the AC-DC converter of the charging pile to be in an open state.

[0064] Preferably, the two electrodes of the standard power sensor are set as pluggable plugs, and the pluggable plugs are matched with the charging gun.

[0065] Preferably, the power sensor of the charging pile includes the power sensor of the pile itself, the power sensor for charging fee settlement, and the power sensor shared by adjacent charging piles. The power error is jointly composed of the errors of the three parts: the power sensor of the pile itself, the power sensor for charging fee settlement, and the power sensor shared by adjacent charging piles.

[0066] In a fourth aspect, an embodiment of the present invention provides an electric energy error detection circuit based on virtual quantity interconnection. The detection circuit includes:

[0067] The power sensor of the pile itself of the charging pile, the standard power sensor, the charging fee power sensor, the AC-DC power supply of the charging pile, and the power sensor shared by adjacent charging piles are connected in series to form their respective charging circuits;

[0068] Two adjacent charging lines pass through a shared power sensor. The power sensors of the two adjacent charging piles respectively, and the shared power sensor form an electric energy error detection circuit with virtual quantity interconnection through the charging lines.

[0069] By changing the original charging metering circuit, the present invention transforms the design in which the first metering module originally forms a charging metering circuit by being connected in series with the first charging gun through the first neutral line, and instead, the first metering module is connected to the second neutral line where the adjacent second metering module is located through a wire; by leading out a first wire from the second neutral line and connecting it to the first charging gun, a charging metering circuit for the first charging gun is formed; and a first common power sensor is connected in series between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line on the second neutral line, thereby building a first-level monitoring line, and according to the way of building the first-level monitoring line, the monitoring lines in the entire charging pile cluster are built. If the metering error of any one metering module in the charging pile cluster with the monitoring lines built is known, the errors of the metering modules of the other charging piles in the monitoring line can be obtained. Therefore, large-scale monitoring of the metering errors of the metering modules in the charging piles can be realized, greatly improving the monitoring efficiency and reducing the monitoring cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0071] Figure 1 is a flowchart of a method for implementing a metering monitoring line of a charging pile cluster provided in Embodiment 1 of the present invention;

[0072] Figure 2 is a schematic structural diagram of a method for implementing a metering monitoring line of a charging pile cluster provided in Embodiment 1 of the present invention;

[0073] Figure 3 is a schematic structural diagram of a method for implementing a metering monitoring line of a charging pile cluster provided in Embodiment 1 of the present invention;

[0074] Figure 4 is a schematic structural principle diagram of a toggle switch provided in Embodiment 1 of the present invention;

[0075] Figure 5 is a schematic flowchart of a method for detecting the power metering error of interconnected charging metering lines provided in Embodiment 2 of the present invention;

[0076] Figure 6 is a schematic structural diagram of a charging pile cluster provided in Embodiment 3 of the present invention;

[0077] Figure 7 is a schematic diagram of adjacent charging metering lines provided in Embodiment 3 of the present invention;

[0078] Figure 8 It is a schematic flowchart of a method for detecting electric energy error based on virtual quantity interconnection provided in Embodiment 4 of the present invention;

[0079] Figure 9 It is the circuit diagram of a charging pile cluster provided in Embodiment 4 of the present invention;

[0080] Figure 10 It is the equivalent circuit diagram of the first charging pile connected in series with a standard electric energy sensor provided in Embodiment 4 of the present invention;

[0081] Figure 11 It is the equivalent circuit diagram of the first charging pile and the second charging pile in the on state provided in Embodiment 4 of the present invention;

[0082] Figure 12 It is a schematic flowchart of a method for detecting electric energy error based on virtual quantity interconnection provided in Embodiment 4 of the present invention;

[0083] Figure 13 It is a schematic flowchart of a method for detecting electric energy error based on virtual quantity interconnection provided in Embodiment 4 of the present invention;

[0084] Figure 14 It is the equivalent circuit diagram for calibrating the charging line of a charging pile provided in Embodiment 5 of the present invention;

[0085] Figure 15 It is the equivalent circuit diagram of a method for detecting electric energy error based on virtual quantity interconnection provided in Embodiment 5 of the present invention;

[0086] Figure 16 It is a schematic flowchart of a method for detecting electric energy error based on virtual quantity interconnection provided in Embodiment 5 of the present invention. Detailed implementation manners

[0087] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

[0088] In the description of the present invention, the orientation or positional relationship indicated by the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0089] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0090] Example 1:

[0091] To solve the foregoing problems, in this embodiment, the metering and monitoring circuit of the charging pile cluster is improved, which is applicable to the metering and monitoring circuit of the already constructed charging pile cluster. The metering and monitoring circuit is refitted, and the main improvement methods are as described below. The embodiments of the present invention focus on protecting the connection mode of the entire metering and monitoring circuit. The common power sensor and the metering module in the adjacent monitoring circuit mainly exist in the form of independent modules in the following text.

[0092] Embodiment 1 of the present invention provides a method for implementing the metering and monitoring circuit of a charging pile cluster, as Figure 1 shown. The metering modules of each charging pile are connected in series on the neutral line of the corresponding charging circuit. The implementation method includes:

[0093] Step 101: Change the design that the first metering module is originally connected in series with the first charging gun through the first neutral line to form a charging metering circuit, so that the first metering module is connected to the second neutral line where the adjacent second metering module is located through a wire; after leading out a first wire on the second neutral line and connecting it to the first charging gun, a charging metering circuit for the first charging gun is formed.

[0094] As Figure 2 shown, one charging pile corresponds to one charging gun, each charging gun has its own metering module, and each charging pile corresponds to a AC / DC converter; for example, the first charging pile (i.e., the 1# charging pile in Figure 2 ) corresponds to the first charging gun (i.e., the 1# charging gun in Figure 2 ) and the first metering module (i.e., W1J in Figure 2 ). The AC / DC converter A / D:1 is connected to the first metering module W1J through a switch and provides the electric energy required for charging the 1# charging gun; and so on. The second charging pile (i.e., the 2# charging pile in Figure 2 ) corresponds to the second charging gun (i.e., the 2# charging gun in Figure 2 ) and the second metering module (i.e., W2J in Figure 2 ). The AC / DC converter A / D:2 is connected to the first metering module W2J and provides the electric energy required for charging the 2# charging gun. This is not elaborated one by one here.

[0095] In this embodiment, change the design that the first metering module is originally connected in series with the first charging gun through the first neutral line to form a charging metering circuit to: the first metering module W1J is connected to the second neutral line where the adjacent second metering module W2J is located through a wire, and a first wire is led out on the second neutral line. After the first wire is connected to the 1# charging gun, a charging metering circuit for the 1# charging gun is formed.

[0096] Step 102: A first common power sensor is connected in series on the second neutral line, between the node where the first metering module is connected to the second neutral line and the node of the first wire drawn from the second neutral line, thereby establishing a first-level monitoring line.

[0097] On the second neutral line, between the node where the first metering module W1J is connected to the second neutral line and the node of the first wire drawn from the second neutral line, connect the first common power sensor (i.e., Figure 2 W1 in

[0098] ), thereby establishing a first-level monitoring line.

[0099] For example: The second metering module W2J is connected to the third neutral line where the adjacent third metering module W3J is located through a wire, and a second wire is drawn from the third neutral line. After the second wire is connected to the 2# charging gun, it forms the charging metering circuit of the 2# charging gun. And between the node where the second metering module W2J is connected to the third neutral line and the node of the second wire drawn from the third neutral line, connect the second common power sensor W2; The third metering module W3J is connected to the fourth neutral line where the adjacent fourth metering module W4J is located through a wire, and a third wire is drawn from the fourth neutral line. After the third wire is connected to the 3# charging gun, it forms the charging metering circuit of the 3# charging gun. And between the node where the third metering module W3J is connected to the fourth neutral line and the node of the third wire drawn from the fourth neutral line, connect the third common power sensor W3, and so on, until the charging metering circuits of all the original charging guns at the end of the entire charging pile cluster are adjusted, thereby completing the monitoring lines in the entire charging pile cluster.

[0100] The monitoring line is either permanently fixed or temporarily established. In the present invention, to implement the establishment of the above monitoring line, it can be achieved by permanently fixing and maintaining the monitoring line, or by temporarily completing the establishment of the monitoring line before the metering error detection. For the permanent method, its impact on the accuracy of the final metering error calculation is smaller; while for the temporary method, on the one hand, the convenience of assembly is not easy to control. Therefore, the recommended implementation method in the present invention is the above permanent method.

[0101] On the second neutral line, between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line, a first common power sensor is connected in series, and further includes:

[0102] The second metering module is located on the second neutral line outside the range between the node where the first metering module is connected to the second neutral line and the node of the first wire led out from the second neutral line. As Figure 2 described, specifically: for example, the second metering module W2J is located on the second neutral line outside the range between the node where the first metering module W1J is connected to the second neutral line and the node of the first wire led out from the second neutral line; for example, the third metering module W3J is located on the third neutral line outside the range between the node where the second metering module W2J is connected to the third neutral line and the node of the second wire led out from the third neutral line. The connection positions of other metering modules are as shown above and will not be elaborated one by one here.

[0103] When performing error detection, the method further includes:

[0104] Connect an electrical energy metering standard device in series on the charging metering loop of the first charging gun, and through the charging operation of the corresponding first charging gun, detect the metering error of the first metering module and / or the metering error of the first common power sensor;

[0105] Connect an electrical energy metering standard device WB in series on the charging metering loop of the No. 1 charging gun. This electrical energy metering standard device WB can be located between the node where the first metering module W1J is connected to the second neutral line and the node of the first wire led out from the second neutral line (as Figure 3 shown), or can also be located at a position outside the range between the node where the first metering module W1J is connected to the second neutral line and the node of the first wire led out from the second neutral line (as Figure 2 shown), so as to facilitate detecting the metering error of the first metering module W1J and / or the metering error of the first common power sensor W1.

[0106] Calibrate the first common power sensor based on the metering error of the first common power sensor, and through the calibrated first common power sensor, during the charging operation of the corresponding second charging gun, detect the metering error of the second metering module and / or the metering error of the second common power sensor.

[0107] Suppose the measurement error of the first common power sensor W1 is detected according to the power measurement standard device WB. Then, based on the measurement error of the first common power sensor W1, the first common power sensor W1 is calibrated. When the corresponding No. 2 charging gun is in the charging state, the measurement error of the second measurement module W2J and / or the measurement error of the second common power sensor W2 are detected. When the No. 2 charging gun is in the charging state and other charging guns are in the idle state, the measurement error W2J of the second measurement module W2J and the measurement error of the second common power sensor W2 can be obtained. When the No. 2 charging gun and the No. 3 charging gun are both in the charging state and other charging guns are in the idle state, the measurement error of the second measurement module W2J can be obtained.

[0108] Connect a power measurement standard device in series on the charging measurement loop of the first charging gun, and through the charging operation of the corresponding first charging gun, detect the measurement error of the first measurement module and / or the measurement error of the first common power sensor. Specifically, it includes:

[0109] When the power measurement standard device is connected in series between the node where the first measurement module is connected to the second neutral line and the node where the first wire is led out from the second neutral line, and is adjacent to the first common power sensor, through the charging operation of the corresponding first charging gun and / or the second charging gun, the measurement error of the first common power sensor is detected. Further, when it is confirmed that the first charging gun is working and the second charging gun is in the idle state, the measurement error of the first measurement module is detected by using the first common power sensor or the power measurement standard device after calibration of the measurement error.

[0110] As Figure 3 shown, when the power measurement standard device WB is connected in series between the node where the first measurement module W1J is connected to the second neutral line and the node where the first wire is led out from the second neutral line, and is adjacent to the first common power sensor W1, through the charging operation of the corresponding No. 1 charging gun and / or the No. 2 charging gun, the measurement error of the first common power sensor W1 is detected. Further, when it is confirmed that the No. 1 charging gun is working and the No. 2 charging gun is in the idle state, the measurement error of the first measurement module W1J is detected by using the first common power sensor W1 or the power measurement standard device after calibration of the measurement error. And by switching the charging state or idle state of each charging gun, the measurement errors of all measurement modules on the monitoring line are obtained. Specifically:

[0111] The first method: If both the No. 1 charging gun and the No. 2 charging gun are in the charging working state (i.e., the charging state), the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are the total value of the currents flowing through the No. 1 charging gun and the No. 2 charging gun. If the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are different, it indicates that the first common electric energy sensor W1 has a measurement error, and this measurement error is the difference between the electric energy metering standard device WB and the first common electric energy sensor W1. Calibrate the first common electric energy sensor W1 according to the detected measurement error of the first common electric energy sensor W1.

[0112] The second method: If the No. 1 charging gun is in the charging working state (i.e., the charging state) while the No. 2 charging gun is in the idle state, at this time, the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are the current flowing through the No. 1 charging gun. If the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are different, it indicates that the first common electric energy sensor W1 has a measurement error, and this measurement error is the difference between the electric energy metering standard device WB and the first common electric energy sensor W1. Calibrate the first common electric energy sensor W1 according to the detected measurement error of the first common electric energy sensor W1.

[0113] The third method: If the No. 2 charging gun is in the charging working state (i.e., the charging state) while the No. 1 charging gun is in the idle state, at this time, the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are the current flowing through the No. 2 charging gun. If the measurement values of the electric energy metering standard device WB and the first common electric energy sensor W1 are different, it indicates that the first common electric energy sensor W1 has a measurement error, and this measurement error is the difference between the electric energy metering standard device WB and the first common electric energy sensor W1. Calibrate the first common electric energy sensor W1 according to the detected measurement error of the first common electric energy sensor W1.

[0114] Based on the above three methods, the measurement error of the first common power sensor W1 can be obtained. After calibrating the first common power sensor W1 based on the measurement error, the 1# charging gun is in the charging state and the 2# charging gun is in the idle state. At this time, the measurement values of the power measurement standard device WB and the first common power sensor W1 are the same and are the current flowing through the 1# charging gun. At this time, the measurement error of the first measurement module W1J can be detected according to the power measurement standard device WB or the calibrated first common power sensor W1; since the measurement error of the first common power sensor W1 calibrated according to the measurement error is 0, based on the first common power sensor W1 calibrated according to the measurement error, the measurement errors of other measurement modules on the monitoring line can be obtained. For example, when the 2# charging gun is in the charging state and other charging guns are in the idle state, at this time, the current flow direction is: from the positive pole Join2+ of the AC / DC converter A / D:2, transmitted through the 2# charging gun to the second wire, transmitted through the second wire to the second common power sensor W2, and then from the second common power sensor W2 transmitted through the wire to the second measurement module W2J, and sequentially transmitted through the second measurement module W2J to the first common power sensor W1 and the power measurement standard device WB and then transmitted to the negative pole of the AC / DC converter A / D:2. Therefore, at this time, the measurement errors of the second measurement module W2J and the second common power sensor W2 can be obtained according to the calibrated first common power sensor W1; after the second common power sensor W2 is calibrated according to the measurement error, when the 3# charging gun is in the charging state and other charging guns are in the idle state, the measurement errors of the third measurement module W3J and the third common power sensor W3 can be obtained, and so on, the measurement errors of all measurement modules on the entire monitoring line can be obtained.

[0115] A power measurement standard device is connected in series on the charging measurement loop of the first charging gun, and through the charging work of the corresponding first charging gun, the measurement error of the first measurement module and / or the measurement error of the first common power sensor is detected. Specifically, it further includes:

[0116] When the power measurement standard device is connected in series on the first neutral line and not on the second neutral line, through the charging work of the corresponding first charging gun, the measurement error of the first measurement module is detected; and further confirm that when the first charging gun is working and the second charging gun is in the idle state, the measurement error of the first common power sensor is detected by using the first measurement module or the power measurement standard device calibrated according to the measurement error.

[0117] Such as Figure 2As shown, the electric energy metering standard device WB is connected in series on the first wire (i.e., connected in series on the first neutral wire and not on the second neutral wire). Through the charging operation of the corresponding No. 1 charging gun, the metering error of the first metering module W1J is detected, and it is further confirmed that when the No. 1 charging gun is in the charging state and the No. 2 charging gun is in the idle state, the metering error of the first common electric energy sensor W1 is detected by using the first metering module W1J or the electric energy metering standard device after calibration of the metering error, and according to the first common electric energy sensor W1 after calibration of the metering error and the metering errors of all metering modules on the monitoring line obtained by switching the charging state or idle state of each charging gun, specifically:

[0118] Put the No. 2 charging gun in the charging state, and all other charging guns are in the idle state. At this time, the current flow direction is: from the positive pole Join2+ of the AC / DC converter A / D:2, through the No. 2 charging gun, to the second wire, through the second wire to the second common electric energy sensor W2, then from the second common electric energy sensor W2 through the wire to the second metering module W2J, and through the second metering module W2J in sequence to the first common electric energy sensor W1 and the electric energy metering standard device WB, and then to the negative pole of the AC / DC converter A / D:2. Therefore, at this time, the metering errors of the second metering module W2J and the second common electric energy sensor W2 can be obtained according to the calibrated first common electric energy sensor W1; after the second common electric energy sensor W2 is calibrated according to the metering error, when the No. 3 charging gun is in the charging state and all other charging guns are in the idle state, the metering errors of the third metering module W3J and the third common electric energy sensor W3 can be obtained, and so on, and the metering errors of all metering modules on the entire monitoring line can be obtained, which will not be elaborated here one by one.

[0119] The metering monitoring line of the charging pile cluster further includes an electric energy data collector and a calculation system; the electric energy data collector is used to collect the metering values of the metering modules, common electric energy sensors and electric energy metering standard devices in each charging pile and transmit them to the calculation system; the calculation system is used to complete the calculation of the metering errors of the metering modules and / or common electric energy sensors. Among them, the transmission method usually adopts wireless transmission, such as transmission through the Bluetooth protocol, transmission through the wifi network or transmission through the 5G network, etc.

[0120] It also includes a detection load; the detection load includes the power battery of an electric vehicle as an actual load for detection, a specially designed equivalent load, or a virtual load simulated by independent current sources and voltage sources respectively.

[0121] Such as Figure 2 and Figure 3As shown in the figure, for each AC / DC converter A / D:n, a switch n is connected in series to its negative terminal, where n is a natural number. For example, the AC / DC converter A / D:1 corresponds to switch 1, the AC / DC converter A / D:2 corresponds to switch 2, and so on. Details are not elaborated here one by one.

[0122] The implementation method further includes: a toggle switch or a wireless transmitter is provided in the charging gun of each charging pile; wherein, the toggle switch is in a closed state when the charging gun is working, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in a closed state; and is also in an open state when the charging gun is idle, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in an open state.

[0123] As Figure 4 shown, the most suitable placement position of the toggle switch is on the side wall of the charging port of the charging gun. Utilizing the characteristic that the charging gun is plugged into the charging port on the vehicle, the charging male port on the vehicle pushes open the toggle switch arranged on the side wall of the charging female port of the charging gun, so that Figure 4 the toggle switch shown is closed, and the corresponding toggle switch is connected to the switch shown (for example: switch 1, switch 2 or switch n), and the corresponding switch belongs to a weak-current controlled electromagnetic switch. That is, when the toggle switch is closed, a corresponding weak-current forms a loop and provides an electromagnetic adsorption force to the electromagnetic switch, thereby completing the closing of the electromagnetic switch shown, so as to ensure that after having the improved structure shown, only when charging a load such as an electric vehicle, the metering module of the corresponding charging gun will be connected to the power supply circuit of the charging pile, otherwise the metering module is in an electrically isolated state relative to the charging pile. Figure 4 Figure 4 Figure 4

[0124] The implementation method further includes: a wireless transmitter is provided in the charging gun of each charging pile; wherein, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in a closed state; and is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in an open state.

[0125] Figure 4 Figure 4 ​​​​​For example, the switch 1 shown needs to be in the off state. In this case, the wireless transmitter lacks power supply, and when the charging gun is inserted into the charging interface of the load object, the first wireless signal cannot be transmitted. Therefore, during the implementation of the embodiments of the present invention, it is utilized that the charging interface of the load to be charged (such as an electric vehicle) will also release current after being connected with the charging gun. Therefore, the power interface of the wireless transmitter can be connected to the power supply interface of the charging gun, so that when the charging gun is inserted into the load for charging, the wireless transmitter is first supplied with power by the remaining power in the load to send the first wireless signal, thereby completing Figure 4 the closing of the switch located on one side of the AC / DC converter as shown, enabling the charging gun to be connected to the AC / DC converter, and thus entering the normal charging state.

[0126] Embodiment 2:

[0127] An electric vehicle charging pile is a specific product form of a charging pile. An electric vehicle charging pile is a measuring instrument for charging electricity trading, and the error detection technology for it is very important. The rapid development of electric vehicles has led to a sharp increase in the number of charging piles, and there is an urgent need for efficient charging pile electricity metering error detection technology in the market. Currently, there are two types of methods for detecting the electricity metering error of a charging pile cluster. One is to use a dedicated charging pile metering error detection device to detect and calibrate one charging pile at a time for the first error. This technology takes a long time and has a high cost, and cannot meet the market demand for the error calibration of the charging pile cluster; the other is to study adding intelligent devices, standard electricity meters, and / or other metering components to the charging pile. This type of method will increase the charging pile error detection cost and affect the reliability of the safe operation of the charging pile.

[0128] In order to be able to scale the detection of the electricity metering error of the charging pile cluster, improve the charging pile error detection efficiency, reduce the detection cost, and meet the market demand, the embodiments of the present invention provide a method for detecting the electricity metering error with interconnected charging metering lines. This method for detecting the electricity metering error is implemented based on the metering monitoring line modified in Embodiment 1. Among them, in the actual field of electric vehicle charging piles, some noun objects are adaptively modified. Herein, the charging metering line below can be understood as the monitoring line in Embodiment 1, the shared electricity sensor below can be understood as the public electricity sensor in Embodiment 1, and the electricity metering device below can be understood as the metering module in Embodiment 1 for charging.

[0129] In an actual application scenario, the power metering device inside the corresponding existing charging pile may not be able to interact with the computing system proposed in the embodiments of the present invention. In order to calibrate the error of the power metering device in the traditional charging pile, it is necessary to add a power sensor proposed in the embodiments of the present invention to the line where the power metering device is located in the traditional charging pile, and complete the power sensor that is assigned to each charging pile and is connected in series with the power metering device inside the corresponding charging pile through the method of reporting metering data through it. Thus, in the subsequent use process, it is convenient to directly compare the power metering device on the internal line of each charging pile and the calibrated power sensor connected in series with it, and then the calibration of the metering error of the existing charging pile can be realized.

[0130] Different from Embodiment 1, in the embodiment of the present invention, a power sensor is added to each charging metering line. The added power sensor R1 can have a numerical display function, so that relevant personnel can directly obtain and input it into the system; of course, it can also be without a display function, but instead, based on two identity elements, namely the charging pile identifier and the charging time, the data collected is used to establish an interaction between the computing system proposed by the present invention and the charging station data collection system at the server (cloud platform) level, so as to calculate the metering error of the metering sensor of the charging pile.

[0131] According to the method of this embodiment, it can be ensured that the computing system can obtain the power data on each charging metering line for error calibration. As Figure 5 shown, Embodiment 1 of the present invention provides a method for detecting power metering error with interconnected charging metering lines, and the method includes the following steps:

[0132] Step 100: Each charging metering line is provided with its own power sensor. The charging metering line in this step can be the charging metering line between the power supply of the electric vehicle charging pile and the charging gun. Each charging metering line can represent a charging pile. The power sensor used for each such charging metering line can be one or more. Functionally divided, the power sensor can be a power metering device for billing and settlement, or a power sensor connected in series with the power metering device and used to calculate the error of the power metering device through comparison, or a power sensor for other purposes. And from the measurement type, the power sensor can be a current sensor for measuring current or a voltage sensor for measuring voltage. The power sensor in this embodiment is preferably a current sensor for measuring current.

[0133] Step 200: Every two adjacent charging metering lines pass through a common power sensor to form an interconnection structure of the power metering error detection line. In this step of the preferred embodiment, the power sensors in each charging metering line are arranged on the neutral line side of their own charging metering line. Generally, the neutral lines of the power sensors in every two adjacent charging metering lines jointly pass through the same common power sensor and are connected to each other to realize the series connection of the power sensors of adjacent charging metering lines and the common power sensor. However, in some cases, the common power sensor does not necessarily need to be realized on the neutral line. For example, when the common power sensor between two adjacent charging metering lines is a DC current transformer, there may be no direct electrical connection between the two adjacent charging metering lines on the DC current transformer. In this way, there is no need to worry about the problem that the different voltages and potentials between the charging metering lines affect the accurate metering of electric energy.

[0134] Step 300: By performing time-sharing charging on every two adjacent charging metering lines, the errors between their respective power sensors and the common power sensor are obtained to realize the transfer measurement and calculation of the power metering errors between the charging metering lines. The above two steps realize the interconnection structure between the charging metering lines, and this step is based on the interconnection structure formed by the above steps. By performing time-sharing charging on every two adjacent charging metering lines, the transfer measurement and calculation of the power metering errors between the charging metering lines are realized.

[0135] In this preferred embodiment, for every two adjacent charging metering lines, one is the first charging metering line and the other is the second charging metering line. Then when the first charging metering line is charging, the electric energy of its adjacent charging pile, that is, the second charging metering line, is zero. The electric energy of the first charging metering line flows through the power sensor of the first charging metering line and the common power sensor to obtain the first power metering error of the power sensor of the first charging metering line relative to the common power sensor. When the second charging metering line is charging, the electric energy of its adjacent charging pile, that is, the first charging metering line, is zero. The electric energy of the second charging metering line flows through the power sensor of the second charging metering line and the common power sensor to obtain the second power metering error of the power sensor of the second charging metering line relative to the common power sensor. Based on the above measurements, the third power metering error of the power sensor of the first charging metering line relative to the power sensor of the second charging metering line, that is, the power metering error between two adjacent charging metering lines, is obtained through the first power metering error and the second power metering error. By analogy, the transfer measurement and calculation of the power metering errors between all charging metering lines are realized.

[0136] During the above error measurement process, when the error of the power sensor of the first charging metering circuit or the power sensor of the second charging metering circuit relative to the standard power sensor is uncertain, the power metering error between the two power sensors obtained is the difference between their true errors; when the error of one of the power sensors of the first charging metering circuit, the power sensor of the second charging metering circuit, and the common power sensor relative to the standard power sensor is determined, the errors of the remaining two power sensors obtained are the true errors. During this process, a standard power sensor can be serially arranged on the first charging metering circuit or the second charging metering circuit to obtain the true error relative to the standard, or the power sensor of a certain charging metering circuit or the common power sensor can be directly set as the standard power sensor to obtain the true errors of other power sensors.

[0137] In this preferred embodiment, for two adjacent charging metering circuits, when one of the charging metering circuits is charging alone, the other charging metering circuit is in a power-off and deactivated state, and when each charging metering circuit is charging, the common power sensor connected to it is connected to the same voltage signal as its own power sensor. Specifically, when two adjacent charging metering circuits charge separately at different times, they use the common power sensor separately. For example, when the first charging metering circuit uses the common power sensor, the common power sensor is connected to the same voltage signal as the power sensor of the first charging metering circuit; when the adjacent second charging metering circuit uses the common power sensor, the common power sensor is connected to the same voltage signal as the power sensor of the second charging metering circuit. When the first charging metering circuit and the second charging metering circuit use the common power sensor simultaneously, the error measurement and calculation of the power sensors of the charging metering circuits are not performed (this situation can be that two adjacent charging piles charge an electric vehicle at the same time. At this time, because the two charging metering circuits use the common power sensor simultaneously, if the data measured in this case is used for error calculation, the obtained error is inaccurate, so the error measurement and calculation are not performed in this case).

[0138] In this preferred embodiment, a controllable switch is provided on each of the charging metering lines, so that when its adjacent charging metering line is charging, the connection of its own charging metering line can be disconnected, and its own charging metering line is in a power-off and deactivated state. Generally, the controllable switch of each charging metering line is in an open state in the initial state. When charging is required, the controllable switch is closed to start charging. When error detection is not required, multiple charging metering lines (adjacent or non-adjacent) can simultaneously close the controllable switches to work, so as to charge multiple electric vehicles at the same time. When error detection is required, taking two charging metering lines as a group, the controllable switch of one charging metering line can be closed first to obtain the error between the power sensor of this charging metering line and the common power sensor of these two charging metering lines. Then, the controllable switch of this charging metering line is disconnected and the controllable switch of the other charging metering line is opened, so as to obtain the error between the power sensor of the other charging metering line and the common power sensor of these two charging metering lines. Then, the error between the power sensors of the two charging metering lines is obtained through these two errors relative to the common power sensor.

[0139] Based on the above design of the controllable switch, the error measurement process can be to measure the adjacent charging metering lines in sequence. For example, the first charging metering line and the second charging metering line are measured, then the second charging metering line and the third charging metering line are measured, and so on, until all the charging metering lines are measured. In this process, it should be noted that as long as it is not the first or the last charging metering line, each charging metering line in the middle has two common power sensors, one shared with the adjacent charging metering line in front and one shared with the adjacent charging metering line behind. Therefore, in the specific measurement process, when measuring the charging metering line in the middle, only one measurement is needed to obtain the relative error between its power sensor and the two common power sensors in the front and back, instead of measuring twice.

[0140] Considering the case of a relatively large number of charging piles / charging metering lines, this embodiment also provides another fast measurement method. After numbering the charging metering lines in the order of adjacent delay, the odd-numbered charging metering lines are divided into one group, and the even-numbered charging metering lines are divided into another group. During the test, by measuring the charging metering lines of the single-numbered group and the double-numbered group respectively, the relative errors between all charging metering lines can be obtained at one time. For example: the odd numbers such as the first charging metering line, the third charging metering line, and the fifth charging metering line are grouped together, and their controllable switches are closed simultaneously to obtain the relative errors between the power sensors of each charging metering line and the common power sensor connected to it. Because it is measured with a gap in numbers, each common power sensor still shares only one power with the power sensor of the charging metering line connected to it, and there will be no problem when two adjacent charging metering lines are used simultaneously. In this way, the error between the power sensor of each charging metering line and the common power sensor connected to it is still accurate. During this process, the power sensors of each charging metering line can also be numbered (the same as the charging metering line number, such as the first power sensor, the second power sensor, etc.), and the common power sensors connected in series between the power sensors of every two adjacent charging metering lines are also numbered. For example, the first common power sensor is between the first charging metering line and the second charging metering line, the second common power sensor is between the second charging metering line and the third charging metering line, the third common power sensor is between the third charging metering line and the fourth charging metering line, and so on. Then, the relative errors between the first power sensor and the first common power sensor, the relative errors between the third power sensor and the second common power sensor and the third common power sensor... can be obtained from the measurement of the single-numbered group. Similarly, after the measurement of the single-numbered group of charging metering lines is completed, the controllable switches of the single-numbered group are disconnected and the controllable switches of the double-numbered group of charging metering lines are closed. At this time, the relative errors between the second power sensor and the first common power sensor and the second common power sensor, the relative errors between the fourth power sensor and the third common power sensor and the fourth common power sensor... can be obtained. Finally, by unifying the relative errors measured for the single-numbered group and the double-numbered group of charging metering lines, the errors between the power sensors of each charging metering line can be obtained. When using this method, a controllable switch can be set on each charging metering line, and a main switch dedicated to controlling the unified closing and disconnection of the single-numbered group of charging metering lines and a main switch dedicated to controlling the unified closing and disconnection of the double-numbered group of charging metering lines can also be set.

[0141] In summary, the preferred embodiment provides an error detection technology for interconnecting charging metering lines, which can scale the detection of power metering errors in a charging pile cluster, improve the efficiency of charging pile error detection, reduce the detection cost, and meet the market demand.

[0142] Embodiment 3:

[0143] Based on the power metering error detection method for interconnecting charging metering lines provided in Embodiment 2 of the present invention, a specific circuit example is used to further elaborate on the present invention in detail.

[0144] As Figure 6 shown, it is a schematic diagram of the architecture of a charging pile cluster in this embodiment. In actual use, the architecture of the charging pile cluster usually shows that one charging pile is equipped with two independent charging guns, and the two charging guns have their own independent charging metering lines. A AC / DC converter can be independently connected to each charging metering line (as Figure 6 shown, the AC / DC converters A / D:1 and A / D:2 of the 1# charging pile pass through the first charging metering line and the second charging metering line respectively, and provide the electric energy required for charging for the 1# charging gun and the 2# charging gun respectively), or a more powerful AC / DC converter can provide the electric energy required for charging for the two charging guns (not directly shown in Figure 6 ).

[0145] Continuing with the architecture shown in Figure 6 as an example, assuming there are n charging piles in this embodiment, then there are 2n charging metering lines. Among them, the first charging metering line starts from the AC / DC converter A / D:1, passes through switch 1, power metering device W1, power sensor R1, and common power sensor R 12 , and finally reaches the 1# charging gun. The second charging metering line starts from the AC / DC converter A / D:2, passes through switch 2, common power sensor R 12 , power metering device W2, power sensor R2, and common power sensor R 23 , and finally reaches the 2# charging gun. The third charging metering line starts from the AC / DC converter A / D:3, passes through switch 3, common power sensor R 23 , power metering device W3, power sensor R3, and common power sensor R 34 , and finally reaches the 3# charging gun. And so on, until the 2nth charging metering line, which starts from the AC / DC converter A / D:2n, passes through switch 2n, common power sensor R 2n-1，2n , power metering device W 2n , power sensor R 2n , and finally reaches the 2n# charging gun.

[0146] The power metering devices such as W1, W2, and W3 in the above charging metering circuit are also the power metering devices used for billing and settlement mentioned in Embodiment 1, and are specifically used for billing and settlement when charging electric vehicles. The power sensors such as R1, R2, and R3 in the above charging metering circuit are also the power sensors of their respective charging metering circuits mentioned in Embodiment 1, and are specifically used for error measurement (in other embodiments, the power metering devices such as W1, W2, and W3 can also be multiplexed with the power sensors such as R1, R2, and R3). The R 12 、R 23 、R 34 and other common power sensors are also the common power sensors of each group of adjacent charging metering circuits mentioned in Embodiment 1, and are used to cooperate with the power sensors such as R1, R2, and R3 for error measurement. The switches such as switch 1, switch 2, and switch 3 in the above charging metering circuit are also the controllable switches mentioned in Embodiment 1, and are used to control the time-sharing charging and time-sharing error measurement of each charging metering circuit.

[0147] In this embodiment, to realize the interconnection relationship of the above charging metering circuit (interconnecting each charging metering circuit through a common power sensor), it can be in a way of permanently fixing and maintaining the interconnection relationship, or in a way of temporarily completing the connection of the interconnection relationship before the error detection of the charging pile.

[0148] For the permanent method, its impact on the accuracy of the final metering error calculation is smaller; while for the temporary method, on the one hand, the convenience of assembly is not easy to control. Even if a plug-and-play method is set at the corresponding interface to connect the detection wire in the original charging metering circuit of the charging pile, it will also bring problems of impedance consistency, thus bringing unnecessary noise interference to the final calculation result. Therefore, the recommended implementation method in this embodiment is the above permanent method.

[0149] Under the above design, when performing error detection, taking two adjacent charging metering circuits as a group, the controllable switch of one charging metering circuit can be closed first to obtain the error between the power sensor of this charging metering circuit and the common power sensors of these two charging metering circuits, and then the controllable switch of this charging metering circuit is disconnected and the controllable switch of the other charging metering circuit is opened, so as to obtain the error between the power sensor of the other charging metering circuit and the common power sensors of these two charging metering circuits, and then the error between the power sensors of the two charging metering circuits is obtained through these two errors relative to the common power sensor. As Figure 7 shown, taking two adjacent charging metering circuits of the 1# charging pile as an example, first close switch 1 and open switch 2, then the R1, R 12value, then close switch 2 and open switch 1, and the values of R 12 , R2, R 23 can be measured. According to the relative error of the values of R1, R 12 and the relative error of the values of R 12 , R2, the relative error between R1 and R2 can be obtained. The value of R 23 can be used for comparison with the third charging metering circuit in the next round. In the above case, assuming that R1 is a standard electric energy sensor, the relative error of R2 relative to R1 is its true error.

[0150] Continue to refer to Figure 6 , and by expanding and analogizing with the example shown in Figure 7 , the relative error measurement of R2 and R3, the relative error measurement of R3 and R4, and so on until the relative error measurement of R 2n can be carried out according to the time-sharing charging of the second charging metering circuit and the third charging metering circuit. In another way, the odd-numbered charging metering circuits can be grouped into one group, and the even-numbered charging metering circuits can be grouped into one group. First, by closing the switches of the odd-numbered charging metering circuits and opening the switches of the even-numbered charging metering circuits at one time, the values of R1, R 12 , R 23 , R3, R 34 ... R 2n-2，2n-1 , R 2n-1 , R 2n-1，2n are measured, so as to obtain the relative errors of R1, R3... R 2n-1 relative to each adjacent common electric energy sensor. Then, by opening the switches of the odd-numbered charging metering circuits and closing the switches of the even-numbered charging metering circuits at one time, the values of R 12 , R2, R 23 , R 34 , R4, R 45 ... R 2n-1，2n , R 2n are measured, so as to obtain the relative errors of R2, R4... R 2n relative to each adjacent common electric energy sensor. After obtaining the relative errors of each electric energy sensor relative to the adjacent common electric energy sensor, the relative errors between each electric energy sensor can be obtained. When one of all the electric energy sensors is a standard electric energy sensor, the error of other electric energy sensors relative to it is the true error. In one implementation manner, a standard electric energy sensor can also be directly connected in series in a certain charging metering circuit as the measurement standard, and the comparison with other electric energy sensors is the true error.

[0151] In this embodiment, the load for error detection includes the power battery of an electric vehicle as the actual load for detection, a specially designed equivalent load, or a virtual load simulated by independent current sources and voltage sources respectively.

[0152] In this embodiment, a toggle switch or a wireless transmitter is further provided in the charging gun of each charging pile; wherein, when the toggle switch is provided, the toggle switch is in a closed state when the charging gun is working, so as to trigger the switch located on the charging metering line to be in a closed state; it is also used to be in an open state when the charging gun is idle, so as to trigger the switch located on the charging metering line to be in an open state; as Figure 4 shown, the most suitable placement position of the toggle switch is on the side wall of the charging port of the charging gun. Utilizing the characteristic that the charging gun is plugged into the charging port on the vehicle, the charging male port on the vehicle pushes open the toggle switch provided on the side wall of the charging female port of the charging gun, so that Figure 4 the shown toggle switch is closed, and the corresponding toggle switch is connected to the switch shown in Figure 6 shown (for example: switch 1, switch 2 or switch n), and the corresponding switch belongs to a weak-current controlled electromagnetic switch, that is, when the toggle switch is closed, a corresponding weak current forms a loop and provides an electromagnetic adsorption force to the electromagnetic switch, so as to complete the closing of the electromagnetic switch shown in Figure 4 shown, so as to ensure that after having the improved structure shown in Figure 4 shown, only when charging a load such as an electric vehicle, the charging metering route of the corresponding charging pile will be connected to the power supply circuit of the charging pile, otherwise the charging metering route is in an electrically isolated state relative to the charging pile.

[0153] Wherein, when the wireless transmitter is provided, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch on the charging metering line to be in a closed state; it is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch on the charging metering line to be in an open state. Compared with Figure 4 the structure shown, here, if a wireless transmitter is used, because it is necessary to ensure that when the charging gun is not working, the switch 1 shown in Figure 6 shown needs to be in an open state, in this case, the wireless transmitter lacks power supply, and when the charging gun is inserted into the charging interface of the load object, it cannot send the first wireless signal. Therefore, in the implementation process of this embodiment of the present invention, it is utilized that the charging interface of the load to be charged (such as an electric vehicle) will also release current after connecting the charging gun. Therefore, the power supply interface of the wireless transmitter can be connected to the power supply interface of the charging gun, so that when the charging gun is inserted into the load for charging, first, the remaining power in the load supplies the wireless transmitter to send the first wireless signal, so as to complete Figure 6Closing the switch located on one side of the AC / DC converter as shown enables the charging gun to be connected to the AC / DC converter, thus entering the normal charging state.

[0154] In the embodiments of the present invention, the power sensors on the charging metering lines of all charging piles can be embodied as an electricity meter that directly displays values.

[0155] Embodiment 4:

[0156] In the foregoing Embodiment 1 to Embodiment 3, the built charging metering lines were respectively modified. If the metering error of any one metering module in the charging pile cluster with the monitoring line built is known, the errors of the metering modules of other charging piles on the monitoring line can be obtained. The foregoing embodiments focused on describing how to modify the line structure, with the focus on the system architecture, and did not focus on how to calculate the errors of each metering module. This embodiment gives an optimal calculation method process based on the system architecture of the foregoing embodiments; that is, how to most efficiently complete the error calculation method process of the metering sensors in the architecture proposed in the foregoing embodiments.

[0157] Embodiment 4 of the present invention provides an electric energy error detection method based on virtual quantity interconnection. The measurement systems formed by the power sensors common to adjacent charging piles through their respective charging lines satisfy the virtual electric energy conservation relationship, and moreover, the power sensors of each charging pile are connected in series on the zero line of the corresponding charging line, as Figure 8 shown, the detection method includes:

[0158] Step 201: Select two adjacent first charging pile and second charging pile. A first power sensor is provided on the first charging pile, a second power sensor is provided on the second charging pile, and moreover, a common third power sensor is also provided on the line common to the adjacent charging piles.

[0159] As Figure 9 the circuit diagram showing the charging pile cluster, where the power sensors labeled with R (such as R1, R2, R3...) in the figure represent the shared power sensors, the power sensors labeled with W (such as W1, W2, W3...) represent the power sensors of each charging pile of this pile, and the power sensors labeled with "standard" represent the standard power sensors. The first charging pile and the second charging pile in the embodiments of the present invention only represent any two adjacent charging piles in the charging pile cluster. For the convenience of explaining this solution and the consistency of expression, the power sensor for measuring the power of the first charging pile is called the first power sensor, and correspondingly, the sensor for measuring the power of the second charging pile is called the second power sensor. For the sake of distinction, the sensor common to two adjacent charging piles is called the third power sensor.

[0160] Step 202: Install a standard power sensor on the charging line of the first charging pile, use the standard power sensor to calibrate the first power sensor and the third power sensor on the first charging pile, and obtain the absolute error of each of the first power sensor and the third power sensor.

[0161] As Figure 10 shown, it represents the equivalent circuit diagram after the standard power sensor is connected in series to the first charging pile. Connecting the standard power sensor in series is mainly used to measure all the power sensors in the series circuit. In the series circuit, the current in the circuit is the same everywhere. When the standard power sensor is connected in series and the charging circuit in the first charging pile is turned on, the charging circuits of other charging piles remain disconnected. At this time, the first power sensor, the third power sensor, and the standard power sensor are in a series circuit, and the display current (the current value displayed on the sensor) of the three is obtained. In this series circuit, the display current of the standard meter is the standard value in the circuit (the actual current value of the circuit). From the relationship of the series circuit, it can be known that the absolute value of the difference between the first power sensor and the standard power sensor represents the error (absolute error) of the first power sensor. Correspondingly, the absolute value of the difference between the third power sensor and the standard power sensor represents the error of the third power sensor. After obtaining the error, the first power sensor and the third power sensor are calibrated. The actual calibration can be carried out during the measurement process. When the series circuit is turned on, just adjust the display current values of the first power sensor and the third power sensor to be equal to the current display value of the standard power sensor. It should be noted that the absolute current error represents the absolute value of the difference between the display current of the power sensor and the true current of the power sensor.

[0162] Step 203: Establish a virtual quantity interconnected electric energy conservation relationship model to obtain the relationship function of the true electric energy values of the first power sensor, the second power sensor, and the third power sensor; use the calibrated power measurement values of the first power sensor and the third power sensor, and the relationship function of the true electric energy values, to obtain the true value and absolute error of the second power sensor, and finally complete the calibration of the second power sensor.

[0163] Among them, the third power sensor is a power sensor shared by the first charging pile and the second charging pile. When both the first charging pile and the second charging pile are in the on state (charging state), a part of the current in the third power sensor comes from the first charging pile, and another part comes from the second charging pile. As Figure 11As shown, it is an equivalent circuit diagram indicating that the first charging pile and the second charging pile are in a connected state. By analyzing this circuit diagram using the node method, it can be known that the actual current of the third power sensor is equal to the sum of the actual currents of the first power sensor and the second power sensor. The actual currents of the first power sensor, the second power sensor, and the third power sensor form an electric energy conservation relationship function. After calibrating the third power sensor in the previous step, the third power sensor can be used as a standard power sensor to calibrate the shared power sensor connected to the second charging pile later. The corresponding calibration method is the same as that described before. Connect the charging circuit of the second charging pile, and the charging circuits of other charging piles are in a disconnected state; use the calibrated third power sensor as a standard watt-hour meter, and calibrate the second power sensor in the series circuit using the series connection relationship to obtain the absolute error of the second power sensor.

[0164] The present invention obtains the relationship among the first power sensor, the second power sensor, and the third power sensor of adjacent charging piles through the virtual quantity interconnected electric energy conservation relationship. Then, an external standard power sensor is used to calibrate the first power sensor in the first charging pile and the shared third power sensor, and their respective errors are obtained. Then, the calibrated third power sensor is used as a standard meter to achieve the calibration of the second power sensor and the measurement of the error. The measurement of the error of the power sensor in the present invention is actually for calibrating the charging pile. By installing a standard power sensor on the selected charging pile, it is possible to measure and calibrate the errors of all power sensors in adjacent charging piles, thereby improving the efficiency of charging pile error detection and reducing the detection cost; in addition, through intermittent testing, the relationship between the error and time can be obtained, and the longest time that needs to be calibrated within the allowable error time can be calculated, which is convenient for regular calibration of the charging pile.

[0165] After the above content is expanded, the core part of the electric energy error detection method based on virtual quantity interconnection proposed by the present invention has been presented. If it is necessary to specifically describe the process of electric energy detection for virtual quantity interconnection of all charging piles, correspondingly, after completing the calibration of the second power sensor, it also includes the calibration of the power sensors of charging piles other than the first charging pile and the second charging pile, as Figure 12 shown, the specific calibration includes:

[0166] Step 301: Use the calibrated second power sensor or third power sensor as a standard meter, and calibrate the shared power sensor of the charging pile adjacent to the second charging pile using the series connection relationship to obtain the absolute error of the shared power sensor;

[0167] Step 302: Calibrate the on-site power sensor of the charging pile adjacent to the second charging pile by using the virtual quantity interconnected electric energy conservation relationship model and the series connection relationship, and obtain the absolute error of the on-site power sensor;

[0168] Step 303: Then, take the calibrated power sensor of the adjacent charging pile as the standard meter, and sequentially detect and calibrate the power sensors in the subsequent charging piles until all the power sensors in all the charging piles are calibrated.

[0169] Among them, the calibration process of the embodiment of the present invention has transitivity. As Figure 12 shown, after calibrating the power sensor (including the shared third power sensor) in the first charging pile by using the standard power sensor, take the calibrated shared power sensor as the standard meter, calibrate the other shared power sensors on the adjacent charging piles and obtain the corresponding errors; then take the shared power sensor as a link and conduct transmission until the errors of all the power sensors in all the charging piles are obtained and all the power sensors in all the charging piles are calibrated.

[0170] Furthermore, the first charging pile and the second charging pile share the third power sensor, and the neutral lines of the respective charging lines of the first charging pile and the second charging pile jointly pass through the third power sensor.

[0171] For safety, the shared power sensor is set on the neutral line of two adjacent charging piles to ensure that there is no current in the shared power sensor when it is disconnected, and the cross-current loss between the two charging piles can be obtained when the adjacent charging piles are charging simultaneously. By comparing the shared power sensor with the allowed critical value, when the cross loss between two adjacent charging piles is too large (generally, there is an allowed range for the loss, and when it exceeds the allowed range, it can be considered that the loss is too large), it is necessary to repair or transform the lines in the charging pile.

[0172] The charging pile is mainly a metering device for charging electric vehicles. At least one power sensor is provided on each charging pile for the charging billing settlement of the charging pile. The power sensor for billing is only used for the real-time monitoring of the charging power of the electric vehicle; in the actual process, for convenience, a billing unit can be set on the on-site power sensor to replace the originally required additional series-connected power sensor for billing.

[0173] Furthermore, the calibration of the first power sensor and the third power sensor on the first charging pile by using the standard power sensor is as Figure 13 shown, and the specific operation is as follows:

[0174] Step 401: Connect the charging gun of the first charging pile to make the charging circuit of the first charging pile in a conducting state. Keep the charging guns on the charging piles other than the first charging pile in a vacant state. And, the switch located between the power sensor and the AC / DC converter of the charging pile is in a closed state;

[0175] Step 402: Utilize the series connection relationship among the first power sensor, the third power sensor, and the standard power sensor in the conducting state to calibrate the first power sensor and the third power sensor;

[0176] Among them, when the charging gun of the charging pile is in a vacant state, it means that the charging circuit of the charging pile is in an open state. There are two switches on the charging circuit of each charging pile. Whichever switch is opened will make the charging circuit in an open state.

[0177] For the convenience of charging, only by connecting the charging cable of the electric vehicle to the charging gun can charging be realized. The present invention has made certain improvements to the switch between the charging gun and the AC / DC converter of the charging pile. The detection method also includes:

[0178] A toggle switch or a wireless transmitter is provided in the charging gun of each charging pile;

[0179] Among them, the toggle switch is used to be in a closed state when the charging gun is working, thereby triggering the switch located between the power sensor and the AC / DC converter of the charging pile to be in a closed state; it is also used to be in an open state when the charging gun is idle, thereby triggering the switch located between the power sensor and the AC / DC converter of the charging pile to be in an open state; as Figure 11 shown, the most suitable placement position of the toggle switch is on the side wall of the charging port of the charging gun. Utilizing the characteristic that the charging gun is plugged into the charging port on the vehicle, the charging male port on the vehicle pushes open the toggle switch provided on the side wall of the charging female port of the charging gun, making Figure 11 the shown toggle switch closed. And the corresponding toggle switch is connected to the switch between the AC / DC converters of the charging pile. The corresponding switch is a weak-current controlled electromagnetic switch. That is, when the toggle switch is closed, the corresponding weak current forms a loop and provides electromagnetic adsorption force to the electromagnetic switch, thereby completing the closing of the electromagnetic switch as Figure 11 shown, so as to ensure that after having the improved structure as Figure 11 shown, only when charging a load such as an electric vehicle, the metering unit of the corresponding charging pile will be connected to the power supply circuit of the charging pile. Otherwise, the metering unit is in an electrically isolated state relative to the charging pile. Then, once it can be confirmed that each charging gun in the entire charging pile cluster is in an idle state, then a loop can be directly and smoothly formed for detection.

[0180] Among them, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch located between the power sensor and the AC / DC converter of the charging pile to be in a closed state; it is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch located between the power sensor and the AC / DC converter of the charging pile to be in an open state. Compared with Figure 11 the structure shown, here, if a wireless transmitter is used, because it is necessary to ensure that when the charging gun is not working and the switch between the first charging pile AC / DC converters is in an open state, in this case, the wireless transmitter lacks power supply, and when the charging gun is inserted into the charging interface of the load object, the first wireless signal cannot be sent. Therefore, in the implementation process of the embodiment of the present invention, it is utilized that the charging interface of the load to be charged (such as an electric vehicle) will also release current after being connected to the charging gun. Therefore, the power interface of the wireless transmitter can be connected to the power supply interface of the charging gun, so that when the charging gun is inserted into the load for charging, the wireless transmitter is first supplied with power by the remaining power in the load to send the first wireless signal, thereby completing the closing of the switch between the charging pile AC / DC converters, enabling the charging gun to communicate with the AC / DC converter, and thus entering the normal charging state.

[0181] The present invention makes an association between the switch between the charging gun and the AC / DC converter of the charging pile. When an electric vehicle is connected to the charging gun for charging, the paddle switch or the wireless transmitter in the charging gun can emit a signal, so that the switch between the AC / DC converters of the charging pile also performs a closing operation, thereby achieving the purpose of being able to charge as long as the charging gun is connected to the electric vehicle, and simplifying the charging process; when there is a line problem with the charging pile, disconnecting the switch between the charging gun and the AC / DC converter of the charging pile can achieve the disconnection of the other switch, ensuring the safety of the charging pile line.

[0182] The two electrodes of the standard power sensor are set as pluggable plugs, and the pluggable plugs are matched with the charging gun.

[0183] Among them, the charging gun can be understood as a socket-like structure. The charging process is actually a process of connecting the electric vehicle to the charging line, so that the AC / DC power of the charging pile is stored in the electric vehicle; in this process, the electric vehicle plays a role similar to a plug. The standard power sensor for detection is set as a pluggable plug. When detection is required, the standard power sensor can be connected to the charging gun by inserting it. And during the connection process, the charging gun will emit a signal to close the switch between the charging gun and the AC / DC converter of the charging pile, forming a conductive detection circuit. The detection efficiency is more convenient and higher through the plug-and-play method. It should be noted that when setting the standard power sensor as a socket-like structure, a load power supply needs to be set on the standard power sensor. When the standard power sensor is connected to the charging gun, the set load power supply can supply power to the wireless transmitter, thereby realizing the closing operation of the switch between the AC / DC converters of the charging pile.

[0184] Furthermore, the power sensors of the charging pile include the power sensor of this pile, the power sensor for charging fee settlement, and the power sensor shared by adjacent charging piles. The power error is jointly composed of the errors of the three parts: the power sensor of this pile, the power sensor for charging fee settlement, and the power sensor shared by adjacent charging piles.

[0185] Through the series connection method, the present invention can realize the error detection and calibration of all power sensors. By the virtual quantity interconnection and electric energy conservation relationship, the relationship between the power sensors of adjacent charging piles is obtained. Then, all the power sensors (including the common power sensor) on the charging line among many charging piles are selected for calibration and error detection, and the calibrated common power sensor is used as the standard power sensor. It can be realized that only by installing a standard power sensor on one selected charging pile, the error detection and calibration of all the power sensors of the charging piles can be achieved, thereby improving the charging pile error detection efficiency and reducing the detection cost.

[0186] Embodiment 5:

[0187] Such as Figure 14 、 Figure 15As shown in the figure, the electric energy error detection circuit based on virtual quantity interconnection of the present invention includes the on-pile electric energy sensor of the charging pile, the standard electric energy sensor, the billing electric energy sensor, the AC / DC power supply of the charging pile, and the electric energy sensor shared by adjacent charging piles, which are connected in series to form their respective charging circuits; it means that two adjacent charging lines pass through a shared electric energy sensor, and the electric energy sensors of each of the two adjacent charging piles and the shared electric energy sensor form an electric energy error detection circuit with virtual quantity interconnection through the charging lines. First, by connecting the circuit path with the standard electric energy sensor in series, the errors of all electric energy sensors in the path are detected, and all electric energy sensors in the series circuit are calibrated; then, using the electric energy error detection circuit with virtual quantity interconnection, the true current and error of the adjacent on-pile electric energy sensors are obtained, and the adjacent on-pile electric energy sensors are calibrated.

[0188] As Figure 16 shown, it represents the flow chart of using the error detection circuit to detect the errors of electric energy sensors in all charging piles, specifically including:

[0189] Step 501: By comparing the measured values of the standard electric energy sensor and other electric energy sensors of the charging pile, the absolute error of each electric energy sensor of the on-pile is obtained;

[0190] Step 502: Using the calibrated shared electric energy sensor as the standard electric energy sensor of the adjacent charging pile, measure the absolute error of each electric energy sensor of the adjacent charging pile, so as to obtain the measurement error of all electric energy sensors in all charging piles.

[0191] Step 503: Using the electric energy conservation relationship with virtual quantity interconnection and the true electric energy function relationship between the on-pile electric energy sensors of two adjacent charging piles and the shared electric energy sensor, obtain the true value of the on-pile electric energy sensor of the adjacent charging pile, and then obtain the error of the on-pile electric energy sensor of the adjacent charging pile, and perform calibration.

[0192] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. The storage medium can include: read-only memory (ROM, Read Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, etc.

[0193] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for implementing a metering and monitoring circuit of a charging pile cluster, characterized in that, The neutral line circuit of the current sensor with a billing electric energy metering device of the monitored charging pile passes through the current sensor of the electric energy sensor shared with the adjacent charging pile. The implementation method includes: Changing the original design of the first metering module forming a charging metering circuit by connecting in series with the first charging gun through the first neutral line, and instead connecting the first metering module to the second neutral line where the adjacent second metering module is located through a wire; after leading out a first wire on the second neutral line and connecting it to the first charging gun, a charging metering circuit for the first charging gun is formed; A first common electric energy sensor is connected in series on the second neutral line, and between the node where the first metering module is connected to the second neutral line and the node where the first wire is led out on the second neutral line, thereby building the first - level monitoring line; According to the method of building the first - level monitoring line for the first charging gun and the second charging gun, build the second - level monitoring line relationship between the original second metering module, the second charging gun, the third metering module, the third neutral line and the second common electric energy sensor, until the charging metering circuit of the original charging gun at the end of the entire charging pile cluster is adjusted, thereby building the monitoring line in the entire charging pile cluster.

2. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 1, wherein A first common electric energy sensor is connected in series on the second neutral line, and between the node where the first metering module is connected to the second neutral line and the node where the first wire is led out on the second neutral line. It also includes: The second metering module is located on the second neutral line other than between the node where the first metering module is connected to the second neutral line and the node where the first wire is led out on the second neutral line.

3. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 1, characterized in that, When performing error detection, the method further includes: Connect an electric energy metering standard device in series on the charging metering circuit of the first charging gun, and through the charging operation of the corresponding first charging gun, detect the metering error of the first metering module and / or the metering error of the first common electric energy sensor; Calibrate the first common electric energy sensor based on the metering error of the first common electric energy sensor, and through the calibrated first common electric energy sensor, during the charging operation of the corresponding second charging gun, detect the metering error of the second metering module and / or the metering error of the second common electric energy sensor.

4. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 3, characterized in that, The step of connecting an electric energy metering standard device in series on the charging metering circuit of the first charging gun and through the charging operation of the corresponding first charging gun to detect the metering error of the first metering module and / or the metering error of the first common electric energy sensor specifically includes: When the electric energy metering standard device is connected in series between the node where the first metering module is connected to the second neutral line and the node where the first wire is led out on the second neutral line and is adjacent to the first common electric energy sensor, through the charging operation of the corresponding first charging gun and / or the second charging gun, detect the metering error of the first common electric energy sensor; and further confirm that when the first charging gun is working and the second charging gun is in an idle state, use the first common electric energy sensor or the electric energy metering standard device after calibrating the metering error to detect the metering error of the first metering module.

5. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 3, characterized in that, A power metering standard device is connected in series to the charging metering circuit of the first charging gun, and through the charging operation of the corresponding first charging gun, the metering error of the first metering module and / or the metering error of the first common power sensor are detected. Specifically, it further includes: When the power metering standard device is connected in series to the first neutral wire and not on the second neutral wire, through the charging operation of the corresponding first charging gun, the metering error of the first metering module is detected; and further, when it is confirmed that the first charging gun is working and the second charging gun is idle, the metering error of the first common power sensor is detected using the first metering module or the power metering standard device after calibration of the metering error.

6. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 1, characterized in that, It further includes a power data collector and a calculation system; The power data collector is used to collect the metering values of the metering modules, common power sensors and power metering standard devices in each charging pile and transmit them to the calculation system; The calculation system is used to calculate the metering error of the metering module and / or the common power sensor.

7. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 1, characterized in that, It further includes a detection load; The detection load includes the power battery of an electric vehicle as an actual load for detection, a specially designed equivalent load, or a virtual load simulated by independent current sources and voltage sources respectively.

8. The implementation method of the metering and monitoring circuit of the charging pile cluster according to any one of claims 1-7, characterized in that, The monitoring line is permanently fixed or temporarily set up.

9. The implementation method of the metering and monitoring circuit of the charging pile cluster according to any one of claims 1-7, characterized in that, The implementation method further includes: A toggle switch or a wireless transmitter is provided in the charging gun of each charging pile; Among them, the toggle switch is in a closed state when the charging gun is working, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in a closed state; it is also in an open state when the charging gun is idle, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in an open state.

10. The implementation method of the metering and monitoring circuit of the charging pile cluster according to claim 9, characterized in that, The implementation method further includes: A wireless transmitter is provided in the charging gun of each charging pile; Among them, the wireless transmitter is used to send a first wireless signal when the charging gun is working, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in a closed state; it is also used to send a second wireless signal when the charging gun is idle, so as to trigger the switch located between the metering module and the AC / DC converter of the charging pile to be in an open state.

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