Conduction interference wave measuring device

Abstract

To provide a conduction interference wave measuring device capable of performing an EMC test by using a signal not affected by noise due to a PLC.SOLUTION: Provided is a conduction interference wave measuring device that measures a conduction interference wave in an EMC test performed on a second device connected to a first device via a PLC circuit includes an analysis unit that acquires a target signal including a conduction interference wave by the second device and a PLC signal from the PLC circuit and analyzes the target signal, and a measurement unit that does not measure the target signal during a period in which the PLC signal is superimposed on the conduction interference wave and measures the target signal during a period in which the PLC signal is not superimposed on the conduction interference wave on the basis of the analysis result of the analysis unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an apparatus for measuring conducted interference waves in an EMC (Electro-Magnetic Compatibility) test performed on a vehicle while it is being charged. [Background technology]

[0002] Patent Document 1 describes an electromagnetic wave measurement system that measures the level of electromagnetic waves emitted from an object under test (such as an electrical and electronic device). This electromagnetic wave measurement system discloses that an EMI measurement device (EMI receiver) measures the level of electromagnetic waves using a signal that blocks external noise from the surroundings (EMI from peripheral devices, broadcast waves, urban noise, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-233833 A Summary of the Invention [Problem to be solved by the invention]

[0004] Electric vehicles that use the CCS (Combined Charging System) standard for their charging method communicate with the charging equipment via PLC (power line communication) while charging by connecting a cable to the charging equipment. For this reason, the frequency spectrum measured at the measurement terminal of the artificial power circuit network in the conducted interference measurement in the EMC test performed on an electric vehicle while it is being charged is the spectrum of the conducted interference conducted from the electric vehicle superimposed with the spectrum of the PLC signal. The frequency band of the PLC signal partially overlaps with the frequency band of the conducted interference.

[0005] If PLC noise is included in the EMC test signal, the EMI receiver will be affected by the noise during PLC communication and will be unable to accurately measure the interference spectrum in some frequency bands where the PLC signal and conducted interference overlap. If the interference spectrum cannot be measured accurately, the accuracy of the EMC test will decrease.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a conducted interference measurement device that can perform EMC testing using a signal that is not affected by PLC noise. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the disclosed technology is a conducted interference wave measuring device that measures conducted interference waves in an EMC test performed on a second device connected to a first device via a PLC line, the conducted interference wave measuring device comprising: an analysis unit that acquires a target signal including a conducted interference wave and a PLC signal from the second device from the PLC line and analyzes the target signal; and a measurement unit that, based on the analysis results of the analysis unit, does not measure the target signal during a period when the PLC signal is superimposed on the conducted interference wave, and measures the target signal during a period when the PLC signal is not superimposed on the conducted interference wave. Effect of the Invention

[0008] According to the conducted interference measurement device of the present disclosure, it is possible to perform an EMC test using a signal that is not affected by noise due to the PLC. [Brief description of the drawings]

[0009] [Figure 1] An example of the configuration of a measurement system using a conducted interference wave measuring device according to an embodiment of the present disclosure [Diagram 2] Examples of connections for charging equipment, electric vehicles and artificial mains networks for conducted disturbance measurements [Diagram 3] Example of spectrum measurement using a real-time spectrum analyzer [Figure 4A]A diagram explaining the state of conducted interference measurement when the trigger condition is met. [Figure 4B] A diagram explaining the state of conducted interference measurement when the trigger condition is not met. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The conducted interference measurement device according to the present disclosure focuses on the fact that PLC communication in the CCS standard charging method is performed intermittently, and measures the interference spectrum only during periods when PLC communication is not performed between the charging equipment and the electric vehicle. This makes it possible to perform EMC testing using signals that are not affected by PLC noise. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] <Embodiment> [composition] 1 shows a schematic configuration diagram of a measurement system 1 using a conducted interference measurement device 50 according to an embodiment of the present disclosure. The measurement system 1 shown in FIG. 1 is configured such that a charging facility 10 and an electric vehicle 20 are connected via an artificial power supply network 30, and a signal from the artificial power supply network 30 is acquired by the conducted interference measurement device 50.

[0012] The charging equipment 10 is equipment (first device) capable of charging based on the CCS standard, such as a charging station. The charging equipment 10 is capable of PLC communication with an object to be charged (such as an electric vehicle 20) during charging. The electric vehicle 20 is a vehicle (second device) such as an electric vehicle or a plug-in hybrid vehicle, and is an object to be charged that can receive power from the charging equipment 10 via a cable. The pseudo power supply network 30 is a circuit (PLC line) that enables the conducted interference measurement device 50 to measure conducted interference waves conducted from the electric vehicle 20.

[0013] Fig. 2 is a diagram showing an example in which a charging equipment 10, an electric vehicle 20, and a pseudo power supply circuit network 30 are connected for measuring conducted interference waves in CCS_Mode 4. In Fig. 2, the charging equipment 10 includes a charging equipment control unit 11, a PLC modem 12, and a DC power supply 13. The electric vehicle 20 includes an on-board charging control unit 21, a PLC modem 22, and a battery 23.

[0014] The charging equipment 10 and the electric vehicle 20 use a control pilot line (CP line) and a protective earth line (PE line) to perform PLC communication via PLC modems 12 and 22. The charging equipment 10 uses the DC+ line and DC- line of the charging power supply line to charge the battery 23 of the electric vehicle 20 with a DC power source 13 through a pseudo power supply network 30. Conducted interference waves from the electric vehicle 20 are input from the DC+ line and DC- line to the pseudo power supply network 30 and output to a measurement terminal 31. Since the PE line is also used for PLC communication, a PLC signal is superimposed on the conducted interference waves output to the measurement terminal 31.

[0015] The conducted interference measurement device 50 is a device for measuring conducted interference waves conducted from the electric vehicle 20. This conducted interference measurement device 50 includes a power splitter 51, a real-time spectrum analyzer 52, and an EMI test receiver 53.

[0016] The power splitter 51 is configured to split a signal (hereinafter referred to as the "target signal") output from the artificial power supply network 30 and targeted for the conducted interference measurement into two. This power splitter 51 corresponds to the frequency band of the conducted interference to be measured. One of the split target signals is input to a real-time spectrum analyzer 52, and the other of the split target signals (same as the first signal) is input to an EMI test receiver 53. Note that the power splitter 51 equally distributes the input power, so that each divided signal is half the size of the original signal (target signal), but the magnitude of each divided signal can be corrected by the function of the EMI test receiver 53.

[0017] The real-time spectrum analyzer 52 is a component (analysis unit) for measuring the spectrum of the entire frequency band of the target signal in real time. This real-time spectrum analyzer 52 is an analyzer using the FFT method with a frequency bandwidth of 30 MHz or more, and is equipped with a frequency mask trigger function and a trigger output. The real-time spectrum analyzer 52 observes (acquires) the spectrum of the conducted interference wave and the spectrum of the PLC signal, and can detect a period during which the PLC signal (carrier) is not output by appropriately setting a frequency mask trigger. This detected period during which the PLC signal (carrier) is not output is triggered and output as an analysis result.

[0018] The EMI test receiver 53 is a component (measurement unit) for measuring the conducted interference wave in the target signal. This EMI test receiver 53 has an external trigger input that can respond to a trigger output from the real-time spectrum analyzer 52. If the EMI test receiver 53 is tuned to the frequency of the conducted interference wave to be measured and the trigger output of the real-time spectrum analyzer 52 is connected to the external trigger input and the receiver is placed on standby, the EMI test receiver 53 is triggered in synchronization with the output trigger of the real-time spectrum analyzer 52, so that the spectrum of the conducted interference wave can be measured without being disturbed by the spectrum of the PLC signal.

[0019] If the EMI test receiver 53 is a frequency sweep type receiver, it is sufficient to use the meter function that measures the level of the set frequency without performing frequency sweeping. Also, if the EMI test receiver 53 is of the FFT type, the entire spectrum of the FFT frequency bandwidth can be obtained by setting the measurement time of the conducted interference spectrum shorter than the generation interval of the PLC signal (carrier) instead of a specific frequency.

[0020] [Measurement method] A method for measuring a conducted interference wave performed by the conducted interference wave measuring apparatus 50 according to this embodiment will be described with further reference to FIGS. 3, 4A, and 4B.

[0021] Fig. 3 is a diagram showing an example of spectrum measurement by the real-time spectrum analyzer 52. In Fig. 3, in the time domain T1, the target signal is only the conducted interference wave to be measured, so that the spectrum F1 of the conducted interference wave is measured. In the time domain T2, the PLC signal is superimposed on the conducted interference wave as the target signal, so that the spectrum F2 including the frequency components of both the conducted interference wave and the PLC signal is measured. In this embodiment, the frequency mask trigger function of the real-time spectrum analyzer 52 is used to selectively measure only the spectrum F1 of the conducted interference wave.

[0022] The frequency mask trigger of the real-time spectrum analyzer 52 is set so that it can detect the absence of a PLC signal spectrum. When the real-time spectrum analyzer 52 detects the absence of a PLC signal spectrum, the trigger condition is met and a trigger is output from the real-time spectrum analyzer 52. If the EMI test receiver 53 is tuned in advance to the frequency of the conducted interference wave and is in a trigger waiting state, the EMI test receiver 53 is triggered by the trigger output from the real-time spectrum analyzer 52, and the power level p1 of the frequency f1 at this time can be measured (FIG. 4A). FIG. 4A is a diagram for explaining the state of the conducted interference wave measurement when the trigger condition is met.

[0023] On the other hand, when the real-time spectrum analyzer 52 detects the presence of the spectrum of the PLC signal, the trigger condition is not satisfied and no trigger is output from the real-time spectrum analyzer 52. Therefore, the EMI test receiver 53 is not triggered either, and no power measurement is performed (FIG. 4B). FIG. 4B is a diagram for explaining the state of the conducted interference measurement when the trigger condition is not satisfied.

[0024] When using the FFT-type EMI test receiver 53, the spectrum can be measured in a frequency range that depends on the FFT bandwidth by appropriately setting the spectrum measurement time. Therefore, in this case, not only the value of the power level p1 described above but also the entire spectrum can be measured (FIG. 4A).

[0025] <Effects etc.> As described above, according to the conducted interference measurement device 50 according to an embodiment of the present disclosure, when measuring conducted interference in an EMC test performed on the electric vehicle 20 connected to the charging equipment 10 via the pseudo power supply network 30, the target signal including the conducted interference and the PLC signal from the electric vehicle 20 acquired from the pseudo power supply network 30 is analyzed by the real-time spectrum analyzer 52. Then, based on the analysis result of the real-time spectrum analyzer 52, the EMI test receiver 53 does not measure the target signal during a period when the PLC signal is superimposed on the conducted interference, and measures the target signal during a period when the PLC signal is not superimposed on the conducted interference. With this measurement method, the conducted interference measurement device 50 according to the present embodiment can perform an EMC test using a signal that is not affected by noise due to PLC.

[0026] In this embodiment, a conventional EMI receiver can be used to measure conducted interference waves. In addition, the EMI test receiver 53 only needs to satisfy the specifications and performance required by the necessary standards such as EMC testing, and the real-time spectrum analyzer 52 is not required. Therefore, since an EMI test receiver equipped with a high-speed, wideband FFT is not required, a measurement system can be configured at low cost.

[0027] In the configuration of the conducted interference measuring apparatus 50 described above, an attenuator for impedance matching may be inserted before the power splitter 51 (i.e., between the artificial mains network 30 and the power splitter 51). Furthermore, a pulse limiter for preventing transient excessive input, or a high-pass filter for preventing saturation due to excessive input in a frequency range outside the measurement target range may be inserted between this attenuator and the power splitter 51. [Industrial Applicability]

[0028] The conducted interference measuring device disclosed herein can be used to measure conducted interference in an EMC test performed on a vehicle while it is being charged. [Explanation of symbols]

[0029] 1. Measurement system 10 Charging equipment 11 Charging equipment control unit 12 PLC modem 13 DC power supply 20 Electric Vehicles 21 On-board charging control unit 22 PLC modem 23 Battery 30 Pseudo power supply network 31 Measurement terminal 50 Conducted interference measuring equipment 51 Power Splitter 52 Real-time Spectrum Analyzer 53 EMI Test Receiver

Claims

1. A conducted interference measurement device for measuring conducted interference in an EMC test performed on a second device connected to a first device via a PLC line, comprising: an analysis unit that acquires a target signal including the conducted interference wave and a PLC signal from the second device from the PLC line and analyzes the target signal; a measurement unit that, based on an analysis result of the analysis unit, does not measure the target signal during a period when the PLC signal is superimposed on the conducted interference wave, and measures the target signal during a period when the PLC signal is not superimposed on the conducted interference wave.

2. 2. The conducted interference measuring device according to claim 1, wherein the analysis unit is a real-time spectrum analyzer, and uses a frequency mask trigger function to output a trigger indicating the absence of a spectrum of the PLC signal to the measurement unit as the analysis result.

3. the second device is an electric vehicle; the first device is a charging facility that supplies electric power to the electric vehicle, 3. The conducted interference wave measuring device according to claim 1, wherein the EMC test is performed on the electric vehicle while it is being charged.

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