Calibration signal injection for EVSE calibrator

Abstract

An electric vehicle supply equipment (EVSE) calibration device includes a primary conductor, one or more calibration coils, and an ammeter having one or more sensors. The ammeter is coupled to the primary conductor. In the EVSE calibration operating mode, the primary conductor conducts an EVSE current, and the ammeter measures a value indicating a first current induced in one or more sensors by the EVSE current conducted by the primary conductor. In the second operating mode, one or more calibration coils conduct a calibration current, and the ammeter measures a value indicating a second current induced in one or more sensors by the calibration current conducted by one or more calibration coils. The sensors may include sensing coils, magnetic flux sensors, and the like.

Description

[Technical Field]

[0001] This disclosure relates to the calibration of electric vehicle supply equipment (EVSE), also known as electric vehicle charging stations. In particular, this disclosure relates to calibration equipment used to verify whether the measured amount of electrical energy transmitted by an EVSE is accurate. [Background technology]

[0002] As described above, the EVSE needs to be calibrated to verify that the measured amount of electrical energy transmitted by the EVSE is accurate. The calibration process may be specified by regulations or standards and typically involves measuring current and voltage values ​​to determine the amount of power transmitted and verify the proper operation of the EVSE. The measured values ​​are compared to the expected values ​​of the EVSE. The current can typically range between zero and large currents (e.g., up to 1000 amperes) and may need to be measured at several different current levels during the calibration process.

[0003] The current supplied by the EVSE is typically measured by an EVSE calibration device by passing the current through a conductor. As the EVSE-supplied current passes through the conductor, a current, such as a magnetic current within the sensor's core, is induced within the sensor. The value representing the induced current in the sensor is measured by the calibration device, and this measured value is used to generate an index of the EVSE-supplied current.

[0004] The calibration process must be traceable against specified regulations or standards. Therefore, to ensure that the calibration process applied to EVSE is accurate, the calibration device must also be calibrated periodically.

[0005] To calibrate the current measurements of an EVSE calibration device, a calibration shunt can be used to supply the large current required to calibrate the EVSE calibration device. Alternatively, a calibration current source capable of delivering a large calibration current can be used to input a known current to the calibration device without requiring a separate calibration shunt. However, calibration shunts and calibration current sources capable of supplying large calibration currents are not common equipment. Furthermore, maintaining and calibrating a calibration shunt or calibration current source capable of supplying large currents can be costly and time-consuming. [Overview of the Initiative]

[0006] As described above, the current supplied by the EVSE is typically measured by an EVSE calibration device by passing a current through a primary conductor and measuring the current induced in the sensor by the current conducted through the primary conductor. For example, magnetic current can be induced in the core of the sensor. Calibration of an EVSE calibration device typically requires passing a large current through a primary conductor and using a calibration shunt or a calibration current source capable of supplying a large calibration current to perform the calibration measurement.

[0007] In one embodiment, instead of using a large calibration current, a small calibration current can be injected into the EVSE calibration device or calibrator using calibration signal injection, which appears to the EVSE calibration device as being much larger than the injected calibration current. A calibration coil of wire may be wound around the core of the sensor, and the small calibration current passes through the calibration coil of wire. The injected calibration current induces a magnetic current in the core of the sensor of the calibration device. The induced magnetic current appears to the sensor as a magnetic current induced by a current flowing through a primary conductor.

[0008] The ratio of the calibration current (and therefore the calibration current measurement of the EVSE calibration device) to the induced magnetic current is a function of the number of turns in the calibration coil. A large number of turns can be used so that a small calibration current can be used to calibrate a large current measurement by the EVSE calibration device. For example, a calibration coil with 1000 turns can be wound around the core of the EVSE calibration device. A calibration current of 1 ampere can be injected into the calibration coil to calibrate a 1000 ampere reading from the calibration device.

[0009] Since substantially smaller injection calibration currents can be used, calibration shunts or calibration current sources capable of providing larger calibration currents at low uncertainty levels are not required. Instead, the current measurements of the calibration device can be calibrated using a less expensive and more readily available calibration current source, such as a 1-ampere calibration current source.

[0010] In some embodiments, the calibration coil may be embedded in the calibration device, or an external port may be provided on the calibration device for injecting a calibration current into the calibration coil. Calibration devices (and EVSEs) are typically sealed to prevent tampering. Accessing the inside of a calibration device requires breaking the seal, which necessitates recalibrating the entire EVSE calibration device and also carries the risk of exposure to hazardous voltage conditions. By embedding the calibration coil inside the calibration device and providing an external port for injecting the calibration current, it becomes easier to calibrate the calibration device test without damaging the seal, avoiding the need to recalibrate the calibration device while reducing the risk of exposure to hazardous voltage conditions.

[0011] In the embodiment, a coupling having an external port for performing current and voltage calibration of the EVSE charging station calibration device may be provided on the calibration device. This facilitates performing both voltage and current calibration tests of the electric vehicle charging station calibration device using an external connection, eliminating the need to disassemble the calibration device during calibration. [Brief explanation of the drawing]

[0012] [Figure 1] An embodiment of a system including an electric vehicle supply equipment (EVSE) calibration device is shown. [Figure 2] Figure 1 is a conceptual diagram illustrating an embodiment of the calibration of the EVSE calibration device. [Figure 3] An embodiment of a system including an EVSE calibration device is shown. [Figure 4] This is a flowchart illustrating an embodiment of a method for performing a calibration operation. [Modes for carrying out the invention]

[0013] The following description, along with the accompanying drawings, details specific details to provide a complete understanding of the various embodiments disclosed. However, those skilled in the art will understand that the disclosed embodiments can be implemented with or without one or more of these specific details, or in various combinations with other methods, components, devices, materials, etc. In other examples, well-known structures or components related to the environment of this disclosure, including but not limited to interfaces, ports, meters, calibration current sources, coils, sensors, control circuits, electric vehicles, and EVSEs in the EVSE or calibration environment, are not illustrated or described to avoid unnecessarily obscuring the description of the embodiments. Furthermore, the various embodiments may be methods, systems, devices, etc.

[0014] Throughout this specification, claims, and drawings, unless the context indicates otherwise, the following terms have the meanings relating to this specification. The term "in this specification" refers to the specification, claims, and drawings relating to this application. The phrases "in one embodiment," "in another embodiment," "in various embodiments," "in some embodiments," and "in other embodiments," and their variations, refer to one or more features, structures, functions, or limitations of this disclosure. The terms refer to, or characteristics, and are not limited to identical or different embodiments unless specifically indicated in the context. The term "based on" is not exclusive and may refer to additional features, functions, aspects, or limitations not described unless the context indicates otherwise. Furthermore, throughout this specification, the meanings of "a," "an," "one," and "the" include singular and plural references.

[0015] For the purposes of this disclosure, unless otherwise indicated, the phrase "A and B" is non-exclusive and means one or more of (A) and one or more of (B); the phrase "A or B" is non-exclusive and means one or more of (A), one or more of (B), or one or more of (A and B); the phrase "A and / or B" means one or more of (A), one or more of (B), or one or more of (A and B); both the phrase "at least one of A and B" and "one or more of A and B" mean one or more of (A) and one or more of (B); both the phrase "at least one of A or B" and "one or more of A or B" mean one or more of (A), one or more of (B), or one or more of (A and B). As an extension, for example, the phrases "at least one of A, B, or C" and "one or more of A, B, or C" both mean one or more of (A), one or more of (B), one or more of (C), one or more of (A and B), one or more of (A and C), one or more of (B and C), and one or more of (A, B, and C). In the above, A, B, and C represent any form or type such as elements, features, arrangements, components, structures, aspects, actions, processes, etc.

[0016] As described above, the EVSE needs to be calibrated to verify that the measured amount of electrical energy transmitted by the EVSE is accurate. The calibration process may be specified by regulations or standards and typically requires a large amount of electrical energy to be transmitted from the EVSE to the calibration device within a short period of time. For example, some standards require a calibration test at 85% of the maximum transmission current of the EVSE until a specific amount of electrical power is transmitted.

[0017] The calibration device used to calibrate the EVSE typically measures the current and voltage values, determines the amount of power transmitted, and verifies the proper operation of the EVSE. The measured values are compared to the expected values of the EVSE. The current can typically range between zero current and a large current (e.g., up to 1000 amperes) and may need to be measured at multiple different current levels during the current calibration process.

[0018] The current supplied by the EVSE is typically measured by an EVSE calibration device by passing current through a primary conductor. When the current supplied by the EVSE passes through the conductor, a current is induced in one or more sensors. For example, a magnetic current can be induced within the core of the sensor. The value indicating the induced current is measured by the EVSE calibration device, and the measured value is used to generate an indicator of the current supplied by the EVSE. This indicator is compared to the expected value.

[0019] The calibration process needs to be traceable to the specified regulations or standards. Therefore, the EVSE calibration device also needs to be calibrated periodically to ensure that the calibration process is accurate.

[0020] Calibration shunts can be used to calibrate the current measurements of EVSE calibration devices. Calibration shunts need to have a specific resistance at a specific current and under specific environmental conditions. An uncalibrated current source can be used with a calibration shunt, but specific environmental conditions for using the shunt must be met, and such environmental conditions may differ at different current levels being measured. Calibration shunts are not common equipment and are therefore not readily available. Furthermore, in order to provide accurate calibration, the shunt itself must be regularly calibrated, tracked, and maintained in good condition.

[0021] Alternatively, a calibration current source can be used to input a known current to the calibration device. An unknown load or shunt can be used, and a calibration shunt is not required. The calibration current source needs to be able to supply a large calibration current (e.g., up to 1000 amperes) with substantially less uncertainty (e.g., up to four times less) than required under regulations or standards for EVSEs calibrated using the calibration device. Such calibration current sources are not readily available and are costly to use.

[0022] Instead of using a large calibration current, calibration signal injection can be used to inject a small calibration current into the EVSE calibration device or calibrator, which appears to the EVSE calibration device as being much larger than the injected calibration current. One or more calibration coils may be wound around the sensor core, and the small calibration current passes through one or more calibration coils. The injected calibration current induces a magnetic current within the sensor core of the EVSE calibration device, which appears to the EVSE calibration device as a current induced in the core by the current flowing through the primary conductor.

[0023] The ratio of the calibration current to the injected current is a function of the number of turns in one or more calibration coils. A large number of turns can be used, and as a result, significantly smaller calibration currents can be used to calibrate high-current measurements with EVSE calibration devices. For example, a calibration coil with 1000 turns can be wound around the core or toroid of the calibration device. A calibration current of 1 ampere can be injected into the calibration coil to calibrate a 1000-ampere reading from the EVSE calibration device.

[0024] Therefore, a calibration shunt or calibration current source capable of providing a larger calibration current at a small uncertainty level is not required. Instead, a less expensive and more readily available calibration current source, such as a 1-ampere calibration current source, can be used to calibrate the current measurement of the calibration device.

[0025] One or more calibration coils may be embedded in the calibration device, and an external port may be provided on the calibration device for injecting calibration current. EVSE calibration devices (and EVSEs) are typically sealed to prevent tampering. Accessing the inside of an EVSE calibration device requires breaking the seal, which necessitates recalibrating the entire EVSE calibration device. Embedding one or more calibration coils inside the calibration device and providing an external port for injecting calibration current facilitates calibrating the EVSE calibration device without damaging the seal.

[0026] A coupling with external ports for current and voltage calibration of the electric vehicle charging station calibration device may be provided on the calibration device. This coupling facilitates performing both voltage and current calibration tests on the EVSE calibration device using a single calibration instrument and a single cable.

[0027] The external port also eliminates the need to disassemble the EVSE calibration device during the calibration process, while simultaneously reducing the risk of exposure to dangerous voltage conditions.

[0028] Figure 1 shows an embodiment of a system 100 that includes an electric vehicle supply unit (EVSE) 110, also known as a charging station, for supplying electrical energy to an electric vehicle 120. As shown, the EVSE 110 includes a power coupler 112 and a charging cable 113, and the electric vehicle 120 includes a power coupler 122 and a battery 125.

[0029] During operation, electrical energy is supplied to the vehicle 120 by the EVSE 110 via the EVSE's power coupling 112, the charging cable 113, and the vehicle's power coupling 122. The supplied electrical energy can be used, for example, to charge the battery 125 of the electric vehicle 120.

[0030] The EVSE 110 includes a control circuit 114 that controls the distribution of electrical energy by the EVSE 110 and measures the distribution of electrical energy by the EVSE 110. The measured amount may be displayed, for example, on the display 116 of the EVSE 110. The measurement is used so that the amount of payment owned for the provided electrical energy can be determined.

[0031] As described above, the EVSE 110 needs to be calibrated (for example, periodically) to verify that the measured amount of electrical energy transmitted by the EVSE 110 is accurate. In the system 100 of Figure 1, an EVSE calibration device 130 is provided for calibrating the EVSE 110.

[0032] The EVSE calibration device 130 includes a meter 134 for measuring the amount of electrical energy transferred from the EVSE 110 to the EVSE calibration device 130, and a display 136 for displaying the measured amount of electrical energy transferred. Calibration processes that may be specified by regulations or standards typically require a large amount of electrical energy to be transferred from the EVSE (e.g., EVSE 110) to the calibration device (e.g., calibration device 130) in a short period of time. For example, some standards require calibration testing at 85% of the maximum transfer current of the EVSE charging station until a certain amount of power is transferred.

[0033] Referring to Figures 1 and 2, during the calibration of EVSE 110, electrical energy is used by EVSE Power is supplied to the EVSE calibration device 130 via the EVSE 110's power coupling 112, the charging cable 113, and the EVSE calibration device 130's input coupling 132. The charging cable 113 is shown as a dashed line in the coupling of the EVSE 110's power coupling 112 to the input coupling 132 of the EVSE calibration device 130 to indicate that the EVSE 110 will not typically be coupled to both the electric vehicle 120 and the EVSE calibration device 130 at the same time.

[0034] Current I related to the electrical energy supplied to the EVSE calibration device 130 by the EVSE 110. P is current I P The current I is measured by passing it through conductor 138. P This induces a current in one or more sensors 140. For example, sensor 140 may have a core 170. Conductor 138 passes through or is adjacent to core 170. Core 170 may be an air core or a magnetic core, and may be a hollow core of various shapes (e.g., a toroid such as a donut-shaped torus). Current I P When it passes through conductor 138, magnetic current I is introduced into core 170. EVSE This is induced. Sensor 140 detects magnetic current I EVSEIt can sense and use various sensing configurations, as well as combinations of different sensing configurations.

[0035] For example, some embodiments may use one or more sensing coils 172 wound around the core 170. The induced magnetic flux I EVSE induces a current in the sensing coil 172. The value of the current induced in the sensing coil may be measured and functions as an indicator of the induced magnetic flux I EVSE In another example, the core 170 may have one or more air gaps 174, and the sensor 140 may include a magnetic flux sensor 176 for measuring an indicator of the induced magnetic flux I EVSE For example, a Hall effect sensor, a fluxgate, a magnetoresistive sensor (e.g., anisotropic magnetoresistive sensor (AMR), giant magnetoresistive sensor (GMR), tunneling magnetoresistive sensor (TMR), etc.) may be used.

[0036] The sensed value corresponding to the induced current I EVSE is measured by a meter 134 which can be an ammeter, and the measured value is used to generate an indicator of the current supplied by the EVSE 110 to the EVSE calibration device 130. The indicator is displayed on the display 136 and can be compared with an expected value of the indicator. In an embodiment, the ammeter 134 can be rated to measure a current between 0 and 1000 amperes. In some embodiments, the ammeter 134 can be advantageously rated to measure a current between 25 and 500 amperes.

[0037] The EVSE calibration device 130 also needs to be calibrated to verify that measurements performed by the EVSE calibration device 130 for calibrating the EVSE 110 are accurate, for example, within a specified tolerance range. Calibration of the EVSE calibration device 130 may be performed, for example, periodically. To facilitate calibration of the EVSE calibration device 130, the EVSE calibration device 130 includes one or more calibration coils 142 and a calibration coupling 144. In the current calibration operation mode, the calibration coupling 144 is coupled to a calibration current source 160.

[0038] The illustrated calibration current source 160 includes an output coupling 162, a control circuit 164, and a display 166. The control circuit 164 controls the generation of calibration current by the calibration current source 160. The control circuit 164 can perform or control other functions of the calibration current source 160, such as generating a controlled voltage or performing measurement functions. The calibration current source may have a specified calibration current range, for example, a range of 0.0 to 10 amperes, a range of 0.1 to 10 amperes, a range of 0.0 to 30 amperes, a range of 0.01 to 30 amperes, etc.

[0039] During the calibration of the EVSE calibration device 130, the calibration current source 160 receives a calibration current I via the coupling 162 of the calibration current source 160, the cable 168, and the calibration coupling 144 of the EVSE calibration device 130. S The calibration current I is supplied to the EVSE calibration device 130. S The current passes through the calibration coil 142. In some embodiments, multiple calibration coils 142 may be used. For ease of reference, the operation of the embodiments will be described with reference to a single calibration coil 142.

[0040] Calibration current I S As the current passes through the calibration coil 142, the injected calibration current is transferred to the core 170 of the sensor 140 of the EVSE calibration device 130, which contains magnetic current I CAL Induces the induced magnetic current I CAL This means that the calibration device 130 will see the magnetic current as being induced by the current flowing through the primary conductor 138 (for example, induced magnetic current I EVSE (This will appear to be the case.)

[0041] The induced magnetic current I in the sensing coil 140 of the calibration current that has passed through the calibration coil 142 CALThe ratio to (and therefore to the current measurement of the EVSE calibrator 130) is a function of the number of turns of the calibration coil 142. A large number of turns can be used in the calibration coil 142, and as a result, large current measurements by the EVSE calibration device 130 can be calibrated using a small calibration current injection. For example, a calibration coil 142 with 1000 turns can be wound around the core or toroid of the calibration device 130. A calibration current of 1 ampere can be injected into the calibration coil 142 to calibrate a 1000 ampere reading by the calibration device 130. In embodiments, the calibration coil 142 may have 100 to 1000 turns. In practice, in some embodiments, a calibration coil having about 800 turns can be advantageously used.

[0042] Induced magnetic current I EVSE As mentioned above, regarding the induced current I CAL The detected value is measured by meter 134, and the measurement is used to generate an index of the current supplied to the EVSE calibration device 130 by the calibration current source 160. The index is displayed on display 136 and can be compared to the expected value of the index.

[0043] The illustrated system 100 also includes an optional resistive load 310 that facilitates voltage calibration measurements, as will be described in more detail below in the description of Figure 3.

[0044] Embodiments of system 100 in Figure 1 may have more or fewer elements than those shown, the shown elements may be combined, the shown elements may be divided into multiple elements, or otherwise may be modified in various ways. For example, the EVSE calibration device 130 may include a voltmeter and be configured to perform voltage measurements related to the electrical energy supplied to the EVSE calibration device by the EVSE 110. In another example, the EVSE calibration device 130 may include a switch to facilitate coupling of the ports of the calibration coupling 144 to the calibration coil 142 or to other components of the EVSE calibration device 130, such as the primary conductor 138. In yet another example, the EVSE calibration device 130 may include a case in which the various components of the EVSE calibration device 130 are housed, and a seal may be applied to the case to indicate that the EVSE calibration device 130 has not been exposed to hazards (e.g., not opened) since the last calibration operation. In other examples, one or more sensors or sensing coils 140 may be separate from the meter 134, or the calibration coil 142 may be included in the meter 134. The couplings 112, 132, 144, and 164 may have multiple ports, etc.

[0045] Figure 3 shows an embodiment of system 300 including an EVSE calibration device 130 and a calibration current source 160. In Figure 3, the same reference numerals are used to indicate elements similar to those in Figures 1 and 2, and a description of the structure and operation of such corresponding elements can be found in the above description of Figures 1 and 2.

[0046] The illustrated EVSE calibration device 130 includes a case 302 with a seal 304. Couplings 132, 144, and 162 include multiple ports 306. An optional alternative calibration coupling configuration 144' includes a switch 308. The illustrated system 300 also includes an optional resistive load 310 which can facilitate voltage calibration measurements, as will be described in more detail below.

[0047] The seal 304 applied to the seal case 302 restricts access to components of the EVSE calibration device 130, such as the display 136, meter 134, sensor 140, calibration coil 142, primary conductor 138, switch 308, and internal connections of input coupling 132 and calibration couplings 144 and 144' to port 306. Couplings 132, 144, and 144' provide external access to port 306, facilitating coupling the EVSE calibration device 130 to other devices such as the calibration current source 160 or an EVSE (see EVSE 110 in Figure 1). The case may provide restricted access to other components of the EVSE calibration device 130. For example, the display 136 may be visible through the case, and external control devices (not shown), such as switches, may be configurable without opening the case 302 and damaging the seal 304. The integrity of the seal 304 applied to case 302 may indicate that the EVSE calibration device 130 has not been exposed to hazards (e.g., not opened) since the last calibration operation.

[0048] In one embodiment, coupling 144 includes two externally accessible current calibration ports 306c coupled to a calibration coil 142 and two optional externally accessible voltage calibration ports 306v coupled to a primary conductor 138. In an alternative embodiment, coupling 144' includes two externally accessible ports 306' which can be selectively coupled by a switch 308 during operation to perform calibration operations. For example, the two externally accessible ports 306' can be coupled to the calibration coil 142 via the switch 308 to facilitate current calibration operations using calibration signal injection. The two externally accessible ports 306' may also be coupled to the primary conductor 138 and an optional resistive load 310 via the switch 308 to facilitate voltage calibration operations, and the voltage calibration operations are otherwise In this respect, it may be carried out in a conventional manner. The two externally accessible ports 306' can be disconnected from the internal components of the EVSE calibration device 130 by switch 308 in other operating modes, such as when the EVSE calibration device 130 is performing a calibration operation on the EVSE (see EVSE 110 in Figure 1).

[0049] The embodiment of system 300 in Figure 3 may have more or fewer elements than those shown, the shown elements may be combined, the shown elements may be divided into multiple elements, or otherwise may be modified in various ways. For example, the EVSE calibration device 130 or the calibration current source 160, or both, may include a voltmeter and be configured to perform voltage measurements. In another example, the sensor 140, the calibration coil 142, or both may be included in the meter 134.

[0050] Figure 4 illustrates an embodiment of a method 400 for performing a calibration operation, which may be used, for example, with the EVSE calibration device 130, the calibration current source 160, or both, of the system 100 in Figure 1 or the system 300 in Figure 3. Figure 4 will be described with reference to Figures 1 to 3.

[0051] Method 400 begins at 402 to perform a periodic calibration operation related to calibrating the EVSE calibration device 130, or to perform other operations such as calibrating the EVSE 110. Method 400 proceeds from 402 to 404. At 404, Method 400 determines whether to perform the current calibration operation related to the calibration of the EVSE calibration device 130. If at 404 it is not decided to perform the current calibration operation associated with calibrating the EVSE calibration device 130, Method 400 proceeds from 404 to 406, where other calibration operations associated with calibrating the EVSE calibration device 130 or associated with calibrating the EVSE 110 may be performed. For example, the EVSE 110 may be calibrated using the EVSE calibration device 130 as described above with reference to Figures 1 and 2.

[0052] If, in 404, it is decided to perform the current calibration operation associated with calibrating the EVSE calibration device 130, method 400 proceeds from 404 to 408. In 408, method 400 sets up the EVSE calibration device 130 and the calibration current source 160 to perform the current calibration operation associated with calibrating the EVSE calibration device 130. This may be done, for example, by coupling port 306 of coupling 162 of the calibration current source 160 to port 306 of coupling 144 of the EVSE calibration device 130 and configuring the calibration current source 160 to generate a calibration current. In some embodiments, port 306 of coupling 162 of calibration current source 160 is coupled to port 306' of coupling 144' of EVSE calibrator 130, and instead of coupling port 306 of coupling 162 of calibration current source 160 to port 306c of coupling 144 of EVSE calibrator 130, switch 308 may be controlled to couple port 306' to calibration coil 142.

[0053] Method 400 proceeds from 408 to 410. In 410, Method 400 generates a calibrated calibration current for injection into the EVSE calibration device 130. The calibration current can be generated in a conventional manner using a calibration current source 160. Method 400 proceeds from 410 to 412.

[0054] In 412, method 400 injects the generated calibration current into the EVSE calibration device 130. This can be done, for example, by conducting the calibration current through the calibration coil 142 of the EVSE calibration device 130. The method proceeds from 412 to 414.

[0055] In 414, method 400 measures an index of the current in the EVSE calibration device 130 induced by the injected calibration current. This is, for example, as described above, sensor 14 This can be done using 0 and meter 134. The method proceeds from 414 to 416.

[0056] In 416, method 400 determines whether the measured index value of the induced current is within a threshold range of the expected value of the measured index of the induced current. The expected value may be based on the value of the calibration current. A lookup table can be used. The threshold range may typically be 2 percent of the expected value of the calibration current. Other threshold ranges may also be used, such as 0.1 percent of the expected value of the calibration current.

[0057] If, in step 416, the measured index of the induced current is not determined to be within the threshold range of the expected value of the measured index of the induced current, method 400 proceeds from 416 to 418, where a calibration decision is made that the current measurement by the EVSE calibration device 130 is not within the acceptable range. In some embodiments, the index of the decision that the current measurement by the calibration device is not within the acceptable range may be transmitted (e.g., uploaded to a calibration application, to a remote server (not shown)), displayed (e.g., on display 136 or display 166 in Figure 1), documented (e.g., by printing and affixing a seal 304 to the case 302 indicating that the current measurement by the EVSE calibration device 130 is not within the acceptable range, by removing or destroying a seal 304 indicating that the EVSE calibration device 130 is within the acceptable range, by documenting it on paper such as a calibration report), and various combinations thereof. The procedure proceeds from 418 to 424, and other operations may be performed, such as initiating adjustment of the EVSE calibration device 130, recalibrating the EVSE calibration device 130, other operations related to the calibration of the EVSE calibration device 130, and various combinations thereof.

[0058] For example, in some embodiments, method 400 proceeds from 418 to 420, and the EVSE calibration device 130 may optionally be adjusted in response to a determination that the current measurement by the EVSE calibration device 130 is not within an acceptable range. For example, the EVSE calibration device 130 may be adjusted in 420 based on a comparison between the measured index of the induced current and the expected value of the measured index of the induced current. In some embodiments, the adjustment in 420 may include adjusting the offset applied to the current measurement performed by the EVSE calibration device. Method 400 returns from 420 to 402, and the calibration process of the adjusted EVSE calibration device 130 may be performed or repeated. Optional adjustments and recalibrations of the EVSE calibration device 130 are indicated by dashed lines in Figure 4.

[0059] If, in 416, it is determined that the measured index of the induced current is within the expected threshold range, method 400 proceeds from 416 to 422, where the calibration determination may determine that the current measurement by the EVSE calibration device 130 is within an acceptable range or partially within an acceptable range, and this determination may be transmitted, displayed, documented, or various combinations thereof, as described above. The method proceeds from 422 to 424, where other operations may be performed, such as documentation of any adjustments performed in 420 in the previous calibration loop, other operations related to calibrating the EVSE calibration device 130 (e.g., voltage measurement calibration operations), and various combinations thereof.

[0060] The embodiment of method 400 in Figure 4 may include additional operations not shown in Figure 4, may include all of the operations shown in Figure 4, may perform the operations shown in Figure 4 in various orders, may combine operations, may divide operations into individual operations, and may be modified in various ways. For example, Figure 4 may be modified to combine operations 410, 412, and 414, to perform operations 404, 408, 410, 414, 416, 420, and 422, etc., and various combinations thereof, without destroying the seal 304. [Examples]

[0061] In light of the foregoing description, the following list of non-exclusive embodiments illustrates specific implementations of the systems and methods contemplated by this disclosure.

[0062] Example 1: An electric vehicle supply equipment (EVSE) calibration device comprising: a primary conductor that optionally conducts an EVSE current in any EVSE calibration operating mode; one or more calibration coils that optionally conduct a calibration current in a second operating mode; and an ammeter having one or more sensors optionally coupled to the primary conductor, wherein in the EVSE calibration operating mode, the ammeter measures a value indicating a first current induced in one or more sensors by the EVSE current conducted by the primary conductor; and in the second operating mode, the ammeter measures a value indicating a second current induced in one or more sensors by the calibration current conducted by one or more calibration coils.

[0063] Example 2: Example 1, in which optionally, one or more sensors have a core and one or more calibration coils are wound around the core.

[0064] Example 3: Optionally, the core is a toroid, as in Example 2.

[0065] Example 4: Example 1, wherein optionally, one or more sensors include a magnetic flux sensor that measures magnetic flux during operation.

[0066] Example 5: Example 1, in which, optionally, one or more calibration coils contain 100 to 1000 turns.

[0067] Example 6: Optionally, the ammeter is rated to measure the current of the primary conductor between 25 and 1000 amperes, as in Example 5.

[0068] Example 7: Example 1, optionally comprising a coupling including an externally accessible calibration port, wherein in a second operating mode, one or more calibration coils receive a calibration current through one or more of the externally accessible calibration ports of the coupling.

[0069] Example 8: The coupling optionally includes one or more externally accessible current calibration ports, and in the second operating mode, one or more calibration coils receive calibration current via the externally accessible current calibration ports, as in Example 7.

[0070] Example 9: The coupling optionally includes one or more voltage calibration ports coupled to the primary conductor, as in Example 8.

[0071] Example 10: Example 7, optionally comprising a switch, the switch coupling one or more externally accessible calibration ports of coupling to one or more calibration coils in a second operating mode.

[0072] Example 11: Optionally, the case comprises a seal, the seal restricting access to the internal components of the EVSE calibration device, as in Example 7.

[0073] Example 12: Example 1, optionally comprising a case having a seal.

[0074] Example 13: A system comprising, optionally, a calibration current source and an electric vehicle supply equipment (EVSE) calibration device, the electric vehicle supply equipment (EVSE) calibration device comprising a conductor and an ammeter having one or more sensors and one or more calibration coils, wherein in any EVSE calibration operating mode, the conductor is configured to conduct EVSE current, and the ammeter measures a value indicating a first current induced in one or more sensors by the EVSE current. The system is configured such that, in any second operating mode, the EVSE calibration device is coupled to a calibration current source, one or more calibration coils are configured to conduct the calibration current generated by the calibration current source, and an ammeter is configured to measure a value indicating a second current induced in one or more sensors by the calibration current.

[0075] Example 14: Optionally, the ammeter is rated to measure current up to a maximum current, which is at least 500 amperes, as in Example 13.

[0076] Example 15: Optionally, the calibration current source is configured to generate a calibration current up to the maximum calibration current during operation, which is less than 30 amperes, as in Example 14.

[0077] Example 16: A method for calibrating an electric vehicle supply equipment (EVSE) calibration device, the method comprising: optionally using a calibration current source to generate a calibration current; conducting the calibration current through one or more calibration coils of the EVSE calibration device; measuring a value indicating the current induced in the EVSE calibration device by the calibration current conducted through one or more calibration coils; determining whether the measured value indicating the current induced in the EVSE calibration device is within a threshold range of expected values, wherein the expected values ​​are based on the calibration current; and transmitting or displaying a calibration decision based on the determination of whether the measured value indicating the current induced in the EVSE calibration device is within a threshold range of expected values.

[0078] Example 17: Optionally, Example 16, which includes documenting the calibration decision.

[0079] Example 18: Example 16, wherein generating a calibration current optionally includes generating a maximum calibration current of less than 10 amperes.

[0080] Example 19: Example 16, wherein determining whether a measurement is within the threshold range of the expected value optionally includes determining whether a measurement is within 2 percent of the expected value.

[0081] Example 20: Example 16, in which determining whether the measured value is within the expected threshold range optionally includes determining whether the measured value is within 0.5 percent of the expected value of the measured current.

[0082] Example 21: An electric vehicle supply equipment (EVSE) calibration device (130) comprising, optionally, a primary conductor (138) that conducts an EVSE current in any EVSE calibration operating mode, one or more calibration coils (142) that conduct a calibration current in any second operating mode, and an ammeter (134) having one or more sensors (140) coupled to the primary conductor (138), wherein in the EVSE calibration operating mode, the ammeter (134) measures a value indicating a first current induced in one or more sensors (140) by the EVSE current conducted by the primary conductor (138), and in the second operating mode, the ammeter (134) measures a value indicating a second current induced in one or more sensors (140) by the calibration current conducted by one or more calibration coils (142).

[0083] Example 22: Example 21, wherein one or more sensors (140) optionally comprise a core (170), and one or more calibration coils (142) optionally wind around the core (170), and optionally the core is a toroid.

[0084] Example 23: Any of Examples 21 and 22, wherein one or more sensors (140) optionally include a magnetic flux sensor (176) that measures magnetic flux during operation.

[0085] Example 24: Any of Examples 21-23, wherein one or more calibration coils (142) optionally contain 100 to 1000 turns, and optionally an ammeter (134) rated to measure current in a primary conductor (138) of 25 to 1000 amperes.

[0086] Example 25: Any of Examples 21-24, optionally comprising couplings (132, 144, 162) including externally accessible calibration ports (306, 306c, 306v), wherein in a second operating mode, one or more calibration coils (142) receive calibration current through one or more of the externally accessible calibration ports (306, 306c, 306v) of the coupling (132, 144, 162).

[0087] Example 26: The coupling (132, 144, 162) optionally includes one or more externally accessible current calibration ports (306c), and in the second operating mode, one or more calibration coils (142) receive calibration current via the externally accessible current calibration ports (306c), and optionally, the coupling (132, 144, 162) includes one or more voltage calibration ports (306v) coupled to the primary conductor (138), as in Example 25.

[0088] Example 27: Any of Examples 25 and 26, optionally comprising a switch (308), the switch (308) coupling one or more externally accessible calibration ports (306, 306c, 306v) of coupling (132, 144, 162) to one or more calibration coils (142).

[0089] Example 28. Any of Examples 21 to 27, optionally comprising a case (302) having a seal (302), preferably a seal (304) that restricts access to the internal components (134, 136, 138, 140, 142, 146, 170, 172, 174, 176) of the EVSE calibration device (130).

[0090] Example 29: A system (100, 300) comprising, optionally, a calibration current source (160), and an electric vehicle supply equipment (EVSE) calibration device (130), which optionally comprises a conductor (138), an ammeter (134) having one or more sensors (140) and one or more calibration coils (142), wherein in any EVSE calibration operating mode, the conductor (138) is configured to conduct EVSE current, and the ammeter (134) is configured to conduct EVSE current. A system (100, 300) configured to measure a value indicating a first current induced in one or more sensors (140) by an SE current, and in any second operating mode, an EVSE calibration device (130) is coupled to a calibration current source (160), and one or more calibration coils (142) are configured to conduct the calibration current generated by the calibration current source (160), and an ammeter (134) is configured to measure a value indicating a second current induced in one or more sensors (140) by the calibration current.

[0091] Example 30: The ammeter (134) is optionally rated to measure current up to a maximum current, preferably the maximum current is at least 500 amperes, and preferably the calibration current source (160) is configured to generate a calibration current up to a maximum calibration current during operation, preferably the maximum calibration current is less than 30 amperes, Example 29.

[0092] Example 31: A method (400) for calibrating an electric vehicle supply equipment (EVSE) calibration device (130), comprising: optionally using a calibration current source (160) to generate a calibration current (410); conducting the calibration current through one or more calibration coils (142) of the EVSE calibration device (130) (412); and induced in the EVSE calibration device (130) by the calibration current conducted through one or more calibration coils (142). A method (400) comprising measuring a value to be indicated (414), determining (416) whether a measured value indicating a current induced in an EVSE calibration device (130) is within a threshold range of expected values, the expected values ​​being based on a calibration current, and transmitting or triggering a calibration determination (418, 422) based on the determination of whether a measured value indicating a current induced in an EVSE calibration device is within a threshold range of expected values.

[0093] Example 32: Optionally, Example 31, including documenting the calibration decision (418, 422).

[0094] Example 33: Generating a calibration current (410) optionally includes generating a maximum calibration current of less than 10 amperes, as in any of Examples 31 and 32.

[0095] Example 34: Any of Examples 31-33, wherein determining whether the measured value is within a threshold range of the expected value (416) optionally includes determining whether the measured value is within 2 percent of the expected value.

[0096] Example 35: Any of Examples 31-33, wherein determining whether the measured value is within a threshold range of the expected value optionally includes determining whether the measured value is within 0.5 percent of the expected value of the measured current.

[0097] It should be understood that the various embodiments described above may be combined, and further embodiments may be obtained. These and other modifications can be made to the embodiments in consideration of the above "modes for carrying out the invention." In general, the terms used in the following "Claims" should not be interpreted as limiting the "Claims" to the specific embodiments disclosed in the specification and the "Claims," ​​but rather as including all possible embodiments along the entire scope of equivalents for which such "Claims" are granted.

Claims

1. An electric vehicle supply equipment (EVSE) calibration device, In EVSE calibration mode, the primary conductor conducts the EVSE current, In the second operating mode, one or more calibration coils conduct a calibration current, The system comprises an ammeter having one or more sensors coupled to the primary conductor. In the EVSE calibration operation mode, the ammeter measures a value indicating a first current induced in one or more sensors by the EVSE current conducted by the primary conductor. In the second operating mode, the ammeter measures a value indicating a second current induced in one or more sensors by the calibration current conducted by one or more calibration coils, in an electric vehicle supply equipment (EVSE) calibration device.

2. The EVSE calibration device according to claim 1, wherein the one or more sensors comprises a core, the one or more calibration coils are wound around the core, and optionally the core is a toroid.

3. The EVSE calibration device according to any one of claims 1 to 2, wherein the one or more sensors include a magnetic flux sensor that measures magnetic flux during operation.

4. The EVSE calibration device according to any one of claims 1 to 3, wherein the one or more calibration coils comprises 100 to 1000 turns, and optionally the ammeter is rated to measure a current in the primary conductor of 25 to 1000 amperes.

5. An EVSE calibration device according to any one of claims 1 to 4, comprising a coupling including an externally accessible calibration port, wherein in the second operating mode, one or more calibration coils receive the calibration current through one or more of the externally accessible calibration ports of the coupling.

6. The aforementioned connection is The EVSE calibration device according to claim 5, comprising one or more externally accessible current calibration ports, wherein in the second operating mode, the one or more calibration coils receive the calibration current via the externally accessible current calibration ports, and optionally, the coupling comprises one or more voltage calibration ports coupled to the primary conductor.

7. The EVSE calibration device according to any one of claims 5 and 6, comprising a switch, the switch coupling one or more externally accessible calibration ports of the coupling to one or more calibration coils in the second operating mode.

8. An EVSE calibration device according to any one of claims 1 to 7, comprising a case having a seal, preferably the seal restricting access to the internal components of the EVSE calibration device.

9. It is a system, Calibration current source and An electric vehicle supply equipment (EVSE) calibration device, A conductor and An electric vehicle supply equipment (EVSE) calibration device comprising an ammeter having one or more sensors and one or more calibration coils, In EVSE calibration operation mode, The aforementioned conductor is configured to conduct EVSE current, The ammeter is configured to measure a value indicating a first current induced in one or more sensors by the EVSE current. In the second operating mode, The EVSE calibration device is coupled to the calibration current source, The one or more calibration coils are configured to conduct the calibration current generated by the calibration current source. The ammeter is configured to measure a value indicating a second current induced in one or more sensors by the calibration current, in a system.

10. The ammeter is rated to measure current up to a maximum current, preferably the maximum current being at least 500 amperes. Preferably, the calibration current source is configured to generate a calibration current up to a maximum calibration current during operation, and preferably, the maximum calibration current is less than 30 amperes, the system according to claim 9.

11. A method for calibrating an electric vehicle supply equipment (EVSE) calibration device, Using a calibration current source to generate a calibration current, Conducting the calibration current through one or more calibration coils of the EVSE calibration device, The measurement of a value representing the current induced in the EVSE calibration device by the calibration current conducted through one or more calibration coils, The process involves determining whether the measured value indicating the current induced within the EVSE calibration device falls within a threshold range of the expected value, wherein the expected value is based on the calibration current. A method comprising transmitting or displaying a calibration decision based on the determination of whether the value of the measured value indicating the current induced in the EVSE calibration device is within the threshold range of the expected value.

12. A method for calibrating the EVSE calibration device according to claim 11, comprising documenting the calibration decision.

13. A method for calibrating an EVSE calibration device according to any one of claims 11 and 12, wherein generating the calibration current includes generating a maximum calibration current of less than 10 amperes.

14. A method for calibrating an EVSE calibration device according to any one of claims 11 to 13, wherein determining whether the measured value is within the threshold range of the expected value includes determining whether the measured value is within 2 percent of the expected value.

15. A method for calibrating an EVSE calibration device according to any one of claims 11 to 13, wherein determining whether the measured value is within the threshold range of the expected value includes determining whether the measured value is within 0.5 percent of the expected value of the measured current.

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