Device for monitoring the contact between the charging conductors for charging an electric vehicle

Abstract

The invention relates to a technique for monitoring contact between charging conductors (114, 116) of a charging station (200) for charging an electric vehicle (150). According to one aspect, the device (200) comprises a signal generator (202) adapted to output an alternating test signal at the charging conductors (114, 116), and an analysis unit (204) adapted to determine, on the basis of the test signal, whether an electrically conductive contact exists between the charging conductors (114, 116).

Description

Technical Field

[0001] This invention relates to a technique for monitoring contact, preferably short circuit, between charging conductors in a charging station used for charging electric vehicles. Specifically, it discloses an apparatus for monitoring contact between charging conductors, a charging station having such an apparatus, and a charging plug having such an apparatus, but is not limited thereto. Background Technology

[0002] Existing technologies have disclosed methods for identifying short circuits, which involve charging a capacitor with a test voltage and applying the test voltage to the charging cable. Document DE 10 2010042 750 A1 describes such a method.

[0003] However, this conventional method is more complex and costly because a small DC voltage must be coupled to the charging conductor and measured, and the voltage measurement must meet insulation requirements, which requires more complex circuitry.

[0004] In addition, the time curve of the test voltage must be observed in the shortest possible time in order to reliably output the condition when the capacitor stops discharging, which is therefore a relatively slow conventional method.

[0005] Document DE 10 2015 107 161 A1 describes a safety module that monitors multiple sensor values, such as temperature, during charging. However, this monitoring is costly because multiple sensors must be installed and queried. Furthermore, in the presence of a short circuit, initiating charging carries a significant safety risk and a considerable risk of damage due to the large charging current. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a technique for reliably and quickly detecting short circuits between charging conductors.

[0007] The solution of this invention to achieve the above-mentioned objectives is characterized by the features of the independent claims. The beneficial technical solutions and advantageous further solutions of this invention are described in the dependent claims.

[0008] The embodiments of the present invention will now be described in part with reference to the accompanying drawings.

[0009] According to one aspect, an apparatus is provided for monitoring contact between charging conductors in a charging station used for charging electric vehicles. The apparatus includes a signal generator adapted to output alternating test signals on the charging conductors. Furthermore, the apparatus includes an analysis unit adapted to determine, based on the test signals, whether conductive contact exists between the charging conductors.

[0010] This alternating test signal can be a signal that does not only have a DC voltage component (DC component), for example, a signal without a DC component. Alternatively or supplementary, this alternating test signal can oscillate around an average value, for example, as an alternating signal. This alternating test signal can oscillate periodically or aperiodically. The average value may be equal to ground potential.

[0011] The test signal can be high-frequency. For example, the test signal can have a carrier frequency of at least 1 kHz or at least 10 kHz. In addition, the test signal can be monochromatic or harmonic.

[0012] As an alternative or supplementary approach, the test signal may have a distribution in the frequency space (i.e., power spectrum). This test signal may, for example, include pulses or chirps (technically referred to as "chirps").

[0013] Furthermore, each signal waveform (i.e., each carrier frequency or each distribution in the frequency space) can be repeated. Here, the terms "periodicity" and "frequency" (especially the term "high frequency") refer to the frequency of the test signal itself, such as the carrier frequency of the test signal or the frequency in the power spectrum of the test signal. As an alternative or supplementary option, the periodically repeating test signal can have a monitoring rate (monitoring rate).

[0014] Compared to conventional methods based on DC current components, the analysis unit can detect alternating test signals in a cost-effective and reliable manner to determine the contact.

[0015] By outputting alternating test signals, embodiments of the device can distinguish test signals from induced interference in the frequency space, thereby achieving robust short-circuit monitoring. Alternatively or supplementarily, due to frequency-selective attenuation, the test signal can be confined along the charging conductor to a specific test area, making short-circuit monitoring independent of charging stations or electric vehicle components outside the test area.

[0016] The charging conductors can be incorporated into the charging cable that connects to the charging station. The free end of the charging cable can have a charging plug. This charging plug can have contacts for each of these charging conductors.

[0017] Outputting a test signal at the charging conductor can include applying a test signal between the charging conductors or applying a test signal to the charging conductor.

[0018] The conductive contact between charging conductors (referred to as "contact") can also be called a short circuit.

[0019] This test signal can be a voltage signal. This test signal can be the voltage induced between the charging conductors.

[0020] The voltage of the test signal (e.g., the amplitude of the voltage) can be between 10mV and 100mV. When output to (e.g., fed into) the charging conductor, the voltage of the test signal can be converted to a smaller voltage and this voltage can be converted to a correspondingly larger voltage to determine the contact. The voltage can be converted by a coupling element, so, for example, a mV can be applied only at the charging conductor. This test signal is preferably equivalent to a low voltage corresponding to the contact hazard between the charging conductors. The voltage of this test signal is higher than 3V or 12V. Alternatively or supplementary, the voltage of this test signal can be lower than 24V or 50V.

[0021] Alternating test signals can be voltage signals, such as periodic or oscillating voltage distributions. This test signal can also be referred to as a monitoring signal.

[0022] The voltage of the test signal (e.g., the amplitude of alternating test signals) can be a fraction of the charging voltage used to charge the electric vehicle. The frequency of the test signal can differ from the frequency of the charging voltage (e.g., 0Hz for DC charging current).

[0023] The frequency of this alternating test signal can be below 100MHz or 10MHz. As an alternative or supplementary option, the frequency of this alternating test signal can be above 1kHz or 10kHz.

[0024] As an alternative or supplementary approach, the wavelength (e.g., a first wavelength) of the test signal (preferably relative to the charging conductor, which serves as the propagation medium for the test signal) can be greater than the length of the charging conductor and / or charging cable, preferably several times greater. The analysis unit can determine the impedance (e.g., a complex value) between the charging conductors based on the test signal.

[0025] As an alternative or supplementary approach, the wavelength (e.g., a second wavelength) of the test signal (preferably relative to the charging conductor, which serves as the propagation medium for the test signal) can be smaller than the length of the charging conductor and / or charging cable, preferably several times smaller. The analysis unit can be adapted (e.g., in response to the determination of contact between the charging conductors) to determine the propagation time of the test signal and / or the location of the contact. This location can be determined along the charging conductor and / or charging cable based on the propagation time and group velocity of the test signal.

[0026] The alternating test signal can be a harmonic signal. Preferably, this test signal does not include a DC current component.

[0027] The signal generator may include an oscillation circuit.

[0028] Furthermore, the device may include a coupling element connected between the signal generator and the charging conductors, the coupling element being adapted to output a test signal from the signal generator at the charging conductors. The coupling element may electrically isolate the charging conductors from each other and / or from the signal generator.

[0029] Insulation requirements can be met using this coupling element by alternating test signal outputs (e.g., coupled) to a charging conductor and measuring these test signals, without requiring complex circuitry. Alternatively or as a supplement, this coupling element can be adapted to convert the voltage of the test signals.

[0030] The coupling element can capacitively or inductively couple the signal generator to the charging conductor, allowing the signal generator to output a test signal at the charging conductor. Alternatively or as a supplement, this coupling element may include an impedance circuit.

[0031] The signal generator can be coupled to the charging conductor in an inductive and / or capacitive manner.

[0032] The device may include a control unit, or be signal-connected to or capable of signal-connecting to this control unit. This control unit may be adapted to control or regulate the charging or discharging of the electric vehicle.

[0033] The device may include a control unit or a control interface connected to or connectable to this control unit. Furthermore, the analysis unit may be adapted to send a signal to the control unit or at the control interface indicating whether there is conductive contact between the charging conductors.

[0034] If no contact exists, this analysis unit can be adapted to issue a signal to initiate charging. Alternatively or as a supplement, if contact exists, this analysis unit can be adapted to issue a short-circuit signal.

[0035] As an alternative or supplementary solution, the signal generator and / or the analysis unit can communicate with the control unit. This control unit can be adapted to implement or initiate monitoring of the contact between the charging conductors before charging the electric vehicle.

[0036] The control unit can be adapted to output a fault status and / or interrupt the charging current passing through the charging conductor and / or de-energize the charging conductor in the presence of contact.

[0037] The control unit may be adapted to output a fault condition as an alarm signal (e.g., visually and / or audibly and / or tactilely). The charging plug may, for example, include a vibration motor controlled by the control unit to output a tactile alarm signal in response to a contact measurement.

[0038] The control unit can be adapted to electrically isolate the charging conductors from the charging power supply before outputting a test signal and / or determining whether contact exists between the charging conductors. Alternatively or supplementarily, this control unit can be adapted to activate the main relay and / or charging relay of the charging station in response to the determination of contact between the charging conductors.

[0039] As an alternative or supplementary solution, the control unit may be adapted to electrically connect the charging conductor to the charging power source without the need for contact.

[0040] The charging power supply may include a power conversion unit. This power conversion unit may be adapted to apply charging current and / or charging voltage to the charging conductors according to a control unit. A main relay may, according to a control unit, optionally electrically isolate and connect the charging power supply to the power connector when the main relay is open and closed. Alternatively or supplementarily, a charging relay may, according to a control unit, optionally electrically isolate and connect the charging power supply to the charging conductors (preferably each of these charging conductors) when the charging relay is open and closed.

[0041] The control unit may be adapted to output test signals and / or determine the presence of contact by means of a signal generator or analysis unit before charging or discharging the electric vehicle and / or during the electrical isolation of the charging conductor and the power conversion unit and / or before the signal conductor sends a signal for the connection between the charging station and the electric vehicle.

[0042] The test area used to monitor the contact between charging conductors can be limited by means of electrical isolation (e.g., by means of the open state of a charging relay) and / or by means of at least one frequency-selective filtering element.

[0043] The at least one frequency-selective filter element may be arranged or intermediately connected (e.g., on each of the charging conductors or together on these charging conductors) in the output side of the charging station (e.g., the output side of the charging relay) and / or in the charging plug.

[0044] This frequency-selective filter element, or at least one or each of these frequency-selective filter elements, may individually or collectively encapsulate the charging conductor with ferrite and / or include other frequency-selective components (e.g., inductors and capacitors with damping resistance).

[0045] In the presence of contact, the control unit may be adapted to output a fault status of the charging cable or charging plug before the signal conductor of the charging cable or charging plug sends a signal for the connection between the charging station and the electric vehicle, and / or output a fault status of the electric vehicle after the signal conductor of the charging cable or charging plug sends a signal for the connection between the charging station and the electric vehicle.

[0046] The analysis unit is adapted to measure the current driven by the output test signal through the charging conductors. This analysis unit can also be adapted to determine whether there is contact between the charging conductors based on the measured current.

[0047] The analysis unit can be adapted to detect the voltage between the charging conductors constructed by the test signal and / or the current in the charging conductor driven by the test signal, and determine the impedance between the charging conductors based on this voltage and / or this current. Alternatively or supplementarily, if this impedance (preferably the numerical value of the impedance or the active portion of the impedance) is less than or greater than an impedance threshold, the analysis unit can determine that there is contact between the charging conductors.

[0048] The analysis unit can be adapted to detect the attenuation of the test signal. As an alternative or supplementary solution, if the attenuation is greater than or less than an impedance threshold, this analysis unit can determine that there is contact between the charging conductors.

[0049] The analysis unit can be adapted to measure the attenuation of the output test signal through the charging conductors. This analysis unit can also be adapted to determine whether contact exists between the charging conductors based on the measured attenuation. This attenuation can be measured as a change in the test signal applied at the input and / or output of the coupling element.

[0050] The device for monitoring contact can be arranged or implemented in the charging station.

[0051] According to another aspect, a charging station for charging an electric vehicle is provided. The charging station includes a charging power supply and a charging relay, the charging relay being adapted to optionally electrically isolate and connect the charging power supply to the charging conductors of a charging cable used for charging the electric vehicle, in both open and closed states. Furthermore, the charging station includes means for monitoring contact between the charging conductors of the charging station, according to one aspect of the device. Additionally, the charging station includes a control unit adapted to output a test signal at the charging conductors using a signal generator of the device when the charging relay is open, and to determine, using an analysis unit, whether conductive contact exists between the charging conductors based on the test signal. Furthermore, the control unit is adapted to output a fault status if contact exists and / or to close the charging relay to charge the electric vehicle if no contact exists.

[0052] The device for monitoring contact can be arranged or implemented in the charging plug or charging cable.

[0053] According to another aspect, a charging plug for charging an electric vehicle is provided. The charging plug includes charging conductors optionally electrically connected to a charging power source at a charging station via a charging cable, and means for monitoring contact between the charging conductors, according to one aspect of the device.

[0054] In each aspect, the control unit may be arranged or implemented in the charging station and / or in the device for monitoring contact and / or in the charging cable and / or in the charging plug.

[0055] In each aspect, the control unit for charging the electric vehicle can implement a charging method and / or control the charging power supply. The charging method may, for example, include an interrogation signal conductor to initiate charging and / or determine the maximum charging current. Alternatively or supplementarily, controlling the charging power supply may include adjusting the charging current in the charging conductor and / or the charging voltage across the charging conductor.

[0056] Furthermore, each aspect may include the features and functions disclosed within the scope of any other aspect, or the features and functions corresponding thereto. Attached Figure Description

[0057] The present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0058] in:

[0059] Figure 1 This is a schematic block diagram of a charging station, which has a device according to the first embodiment for monitoring the contact between the charging conductors of the charging station;

[0060] Figure 2 This is a schematic block diagram of a device for monitoring the contact between charging conductors according to the second embodiment;

[0061] Figure 3 A schematic block diagram of a charging plug and a device for monitoring contact between charging conductors according to a third embodiment;

[0062] Figure 4 A schematic block diagram of a charging station, a charging plug, and a device for monitoring contact between charging conductors according to a fourth embodiment; and

[0063] Figure 5 This is a schematic block diagram of a filtering element that can be used to limit the test area in each embodiment. Detailed Implementation

[0064] Figure 1This is a schematic block diagram of one embodiment of a charging station for charging an electric vehicle 150 (hereinafter referred to as a vehicle or EV), which is generally designated by reference numeral 100. The charging station 100 may be implemented, for example, as a wall-mounted charging station (also known as a "wall box") or a charging pole.

[0065] The charging station 100 includes a control unit 102 for monitoring or controlling the charging process. The control unit 102 may be adapted, for example, to control or regulate the distribution of charging current and / or charging voltage.

[0066] exist Figure 1 In the illustrated embodiment, charging is performed using direct current (DC). This embodiment of charging station 100, as well as each embodiment disclosed herein, can be modified for another charging method, such as charging using alternating current (AC), particularly using single-phase or multi-phase AC voltage. As an alternative or supplementary solution, each embodiment can be adapted to implement the charging method according to IEC 62196.

[0067] Charging station 100 includes a charging cable 110 with a charging plug 112, through which charging current is supplied to electric vehicle 150 via charging conductors 114 and 116. Additionally, charging station 100 provides a protective grounding conductor 118 (PE) to electric vehicle 150 via the charging cable 110 and its charging plug 112.

[0068] The electric vehicle 150 includes a charging socket 154 complementary to the charging plug 112. When plugged in, this charging socket electrically connects charging conductors 114 and 116 to the electric vehicle 150's power network 156 and / or the electric vehicle 150's traction energy storage device 156, for example, to charge or discharge the electric traction energy storage device 156 installed in the electric vehicle 150. The traction energy storage device 156 may include a battery management system and multiple electrochemical secondary batteries, preferably having lithium ions as mobile charge carriers.

[0069] Furthermore, the charging cable 110 includes a signal conductor for sending signals from the electric vehicle 150 to the charging station 100, preferably to the control unit 102 of the charging station 100. The signal conductor 103 (also referred to in technical terms as "Proximity Pilot" or PP) sends a signal indicating the connection between the charging station 100 and the electric vehicle 150. Optionally, the signal conductor PP sends a signal to the charging station 100 indicating the maximum load capacity of the charging cable 110. For this purpose, a resistor is placed between PP and PE on the electric vehicle 150 side, the value of which indicates the load capacity. The electric vehicle 150 sends a signal indicating its status (e.g., start of charging) to the charging station 100 via the signal conductor CP (Technical term "Control Pilot"), the specific value depending on the resistance between CP and PE.

[0070] Optionally, the control unit 102 includes a modem 104 adapted to communicate with the vehicle control unit 152 of the electric vehicle 150 via conductors CP and / or PE. This modem can modulate and demodulate the communication signals on conductors CP and / or PE using one or more carrier frequencies, i.e., implement carrier frequency communication (also known in technical terms as "Powerline Communication" or PLC). The vehicle control unit 152 of the electric vehicle 150 includes a corresponding vehicle modem 158.

[0071] If a short circuit exists in the charging cable 110 or on the charging plug 112, between the charging conductors 114 and 116 (DC+ and DC- in this case), caused by a conductive interference object at the charging cable 110 or the plug connectors 112 and 154, it is typically not detectable immediately or before the charging process. Instead, a protective element, such as a fuse or line protection switch, must be triggered only if a possible short circuit (e.g., through the resistance R_pre of the pre-charge circuit) is indirectly detected in a more complex test while the charging plug 112 and socket 162 are plugged into the electric vehicle 150, or—if this test is not performed.

[0072] Charging station 100 includes one embodiment of a device, generally indicated by reference numeral 200, for monitoring contact (e.g., impedance) between charging conductors 114 and 116. Device 200 is adapted to detect contact (e.g., impedance) between charging conductors 114 and 116 and determine whether contact exists, for example, whether the detected impedance indicates a short circuit or the presence of faulty impedance.

[0073] If the value of the impedance or the real part of the impedance (i.e., the active part) is less than the threshold value of the impedance (i.e., the minimum value of the impedance), then, for example, a short circuit or fault impedance may exist.

[0074] The device 200 may be adapted to output a fault status and / or interrupt the charging current passing through the charging conductors 114 and 116 and / or de-energize the charging conductors 114 and 116 in response to a detected fault impedance.

[0075] In one embodiment, the charging station 100 includes a charging power supply 106. The charging power supply 106 may be a power conversion unit 106, adapted to output charging current and / or charging voltage at charging conductors 114 and 116, preferably in accordance with the control unit 102. The power conversion unit 106 is powered by a power source (e.g., external to the charging station 100) through a power connector 101. The power conversion unit 106, for example, converts the alternating current supplied by the power source and / or supplied at the power connector 101 into a direct current as the charging current.

[0076] Charging station 100 includes a main relay 107, which is adapted to optionally electrically connect power conversion unit 106 to a power source and electrically isolate power conversion unit 106 from the power source. Alternatively or supplementarily, charging station 100 includes a charging relay 108, which is adapted to optionally electrically connect charging conductors 114 and 116 (preferably respectively) to power conversion unit 106 and electrically isolate power conversion unit 106 from power conversion unit 106.

[0077] This device can be adapted to open the main relay 107 and / or the charging relay 108 in response to a detected fault impedance.

[0078] The device used for impedance monitoring can be used to monitor the contact between charging conductors 114 and 116. A short circuit between charging conductors 114 and 116 is an electrical contact; therefore, contact monitoring can generally be used to detect short circuits.

[0079] The signal generator 202 may include an oscillation circuit.

[0080] The device 200 preferably includes an impedance circuit as a coupling element, having a signal input terminal for the signal generator 202 and a signal output terminal for the charging conductors 114 and 116. The control unit 102 is adapted to apply a test signal as an excitation signal to the signal input terminal. The impedance circuit is adapted to convert the excitation signal into a test signal to be output as a monitoring signal and output this monitoring signal at the signal output terminal for application to the charging conductors 114 and 116.

[0081] In each embodiment, the analysis unit 204 may be adapted to monitor changes in the signal applied to the impedance circuit and, in the event of a change in the signal, determine the contact between the charging conductors 114 and 116. The applied signal may be an excitation signal and / or a monitoring signal.

[0082] In one embodiment, the analysis unit 204 may be adapted to monitor changes in the excitation signal applied to the coupling element (e.g., applied to the impedance circuit) of the signal generator 202 and, in the event of a change in the excitation signal, determine the contact between the charging conductors 114 and 116.

[0083] As an alternative or supplementary solution, the analysis unit 204 can be adapted to detect changes in the monitoring signal.

[0084] Alternatively, in addition to coupling elements (such as impedance circuits), the control unit 102 may also include another signal monitoring circuit for detecting changes in the monitoring signal. This signal monitoring circuit may be adapted to detect changes in the monitoring signal by means of capacitive or inductive coupling.

[0085] Embodiments of device 200 are capable of (preferably even before the charging process of electric vehicle 150) monitoring for potential short circuits in charging conductors 114 and 116, i.e., determining whether a short circuit exists (i.e., short circuit detection). A short circuit is an electrical contact between charging conductors 114 and 116.

[0086] Embodiments of device 200 can determine the presence of a short circuit before the charging process, preferably before the charging plug 112 is inserted into the charging socket 154 of the electric vehicle 150. Device 200 is applicable in principle to both DC and AC charging and is independent of whether energy flows from the charging station 100 to the electric vehicle 150 or from the vehicle to the charging station (i.e., the electric vehicle 150 feeds energy into the network to which the charging station 100 is connected).

[0087] The short circuit measured between charging conductors 114 and 116 may be caused in the charging cable 110 and / or the charging plug 112. Alternatively or supplementarily, with the charging plug 112 of the charging station 100 plugged into the charging socket 154 of the electric vehicle 150, the short circuit measured between charging conductors 114 and 116 may occur in the electric vehicle 150. Variations of each embodiment of the device 200 disclosed herein can be adapted to detect short circuits that may occur in the electric vehicle 150 itself.

[0088] Device 200 can be adapted to distinguish short circuits in the charging cable 110 (or charging plug 112) from short circuits in the electric vehicle 150, for example, based on the propagation time of a signal reflected after output and / or based on the transmission of a signal at signal conductor 103. Other components (e.g., filtering elements) can optionally be integrated into the electric vehicle 150 to determine the presence of short circuits in the electric vehicle 150. Alternatively, device 200 can be adapted to detect these short circuits indiscriminately.

[0089] Figure 2This is a schematic block diagram of a second embodiment of a device 200 for monitoring contacts 212 between at least two charging conductors 114 and 116 used for charging an electric vehicle 150. This second embodiment can be implemented alone or as a further embodiment of the first embodiment. Consistent or interchangeable features in different embodiments are referred to by the same reference numerals.

[0090] The device 200 includes a contact monitoring circuit 205, i.e., a (preferably integrated) unit, which has a signal generator 202 and an analysis unit 204. The signal generator 202 may include an oscillator. The analysis unit 204 may be a detector for a contact (i.e., a short circuit) between the charging conductors 114 and 116.

[0091] In device 200 Figure 2 In the second embodiment shown, the signal generator 202 and the analysis unit 204 are arranged or implemented in the charging station 100.

[0092] Using a coupling element 206, which may be implemented as, for example, a transformer or converter, the test signal of the signal generator 202, applied at the signal input terminal 208 of the coupling element 206, is applied to the charging conductors 114 and 116 through the signal output terminal 210 of the coupling element 206. The charging conductors 114 and 116 carry the charging current (e.g., DC or AC charging current) of the electric vehicle 150. By appropriately determining the dimensions of the coupling element 206, insulation requirements between the control unit 102 or contact monitoring device 200 and the charging conductors 114 and 116, and / or between the charging conductors 114 and 116 and each other, can be met.

[0093] Charging conductors 114 and 116 extend from charging station 100 through charging cable 110 to charging plug 112, which is inserted into or can be inserted into electric vehicle 150 to power the battery or power unit in electric vehicle 150. The charging current for the charging process comes from a charging power source (e.g., charging power source 106, whose energy is fed through power connector 101). The charging process can be initiated, for example, by charging relay 108.

[0094] In the presence of short circuit 212 (especially when it occurs for the first time), as shown here for example by contact closure achieved by means of a nail, the analysis unit 204 determines that short circuit 212 is present and can send a signal (preferably report) to the control unit 102 as a fault condition.

[0095] Control unit 102 can execute, control, or initiate other consequences of signal transmission for short circuit 212. By controlling the open state of charging relay 108, control unit 102 can, for example, prevent the charging process from starting and / or output a fault status, such as as a signal tone.

[0096] The coupling element 206 preferably meets the insulation requirements. For example, the coupling element 206 has electrical isolation between the contacts of the output terminal 210 of the charging conductors 114 and 116 and / or electrical isolation between the input terminal 208 and the output terminal 210.

[0097] When cable 110 is activated by charging relay 108, which acts as a safety switch, a test signal is preferably applied to charging conductors 114 and 116 via coupling element 206. In this case, if cable 110 is not also plugged into electric vehicle 150 via charging plug 112, no contact should occur and testing can be performed.

[0098] If a short circuit 212 (i.e. a contact) exists, shown here for example by a nail that shorts the charging conductors 114 and 116 in cable 110, the contact monitoring circuit 205 can detect this point in advance and will not initiate the charging process.

[0099] Depending on the length of the charging cable 110, it may be advantageous to avoid selecting excessively high test signal frequencies or spectra to, for example, avoid self-resonance and / or radiation effects on the charging cable 110, which could make robust measurements difficult. The frequency or spectrum of the test signal is selected, for example, in such a way that the wavelength of the test signal on the charging conductors 114 and 116 is greater than (preferably much greater than or several times greater than) the length of the charging cable 110 (e.g., the actual or maximum length of the charging cable 110). In the case where the length of the charging cable 110 is several meters, advantageous frequencies may be in the kilohertz range or in the single-digit (maximum double-digit) megahertz range.

[0100] Figure 3 This is a schematic block diagram of a third embodiment of a device 200 for monitoring contacts 212 between at least two charging conductors 114 and 116 used for charging an electric vehicle 150. This third embodiment can be implemented alone or as a further embodiment of the first and / or second embodiments. Features indicated by the same reference numerals in different embodiments may be equivalent, interchangeable, or consistent.

[0101] Figure 3 Showing with Figure 2 A similar basic structure, wherein the charging station 100, charging cable 110, charging plug 112 and / or electric vehicle 150 may each have one or more features described within the scope of the first or second embodiment.

[0102] The third embodiment differs from the second embodiment in that the device 200, preferably the signal generator 202, and the analysis unit 204 or the contact monitoring circuit 205 are placed or implemented in the charging plug 112, for example, placed or implemented outside the charging station 100, unlike the second embodiment.

[0103] Based on the technology implemented in the charging plug 112, the third embodiment may be referred to as a charging plug for detecting short circuits or a smart charging plug 112.

[0104] Preferably, the control unit 102, implemented in the charging plug 112 (e.g., as part of the device 200), can be adapted to send signals to or communicate with the charging station 100. Alternatively or supplementarily, the control unit 102 can control or initiate the following steps using the analysis unit 204: outputting a test signal using a signal generator and / or determining the presence of contact 212. Optionally, the control unit 102 can control charging (or discharging).

[0105] That is, the control of charging can be achieved in the charging station 100 by means of the inherent control unit, or the control unit 102 in the charging plug 112 can also perform this function.

[0106] If the charging plug 112 already contains electronic components 113, such as a control unit 102 (preferably a processor, which may be a microprocessor with memory or a microcontroller), then the third embodiment can preferably be implemented.

[0107] As an alternative or supplementary solution, device 200, particularly control unit 102 within device 200, is connected to charging station 100 via other signal conductors 103 having a data interface and / or via power supply conductors 103 for power supply (e.g., 12V or 24V). This also allows control of signal generator 202 of device 200 from charging plug 112, and enables analysis of test signals (i.e., short-circuit detection signals) and transmission to charging station 100. These test signals are used for measurement (i.e., short-circuit detection) via coupling element 206 and analysis unit 204 of device 200.

[0108] Other components 113 may also be placed on the charging plug 112. These other components 113 may include, for example, a power supply section for powering the control unit 102 and / or the signal generator 202 and / or the analysis unit 204. Alternatively or as a supplement, the other components 113 may include a temperature monitoring unit for monitoring the temperature of the charging conductors 114 and 116.

[0109] To define a test area 111 (e.g., a section of the charging cable 110 and / or the charging plug 112) to determine the presence of a contact (i.e., short-circuit detection or short-circuit test), at least one of the following measures can be implemented. The first measure is to output a test signal and / or perform a short-circuit test only when the charging plug 112 is not plugged into the electric vehicle 150 (i.e., the charging socket 154). The control unit 102 can be adapted to detect the disconnected or unplugged state, for example, based on sending a signal (preferably detecting a resistance value) at the signal conductor 103 (e.g., at the signal conductor PP in the first embodiment). In the electric vehicle 150, a corresponding resistor can be connected between PP and PE. The second measure is to open the charging relay 108 (i.e., the relay contacts of the charging relay 108 are separated), such that the test area 111 for checking for short circuits is restricted in a defined manner toward the charging station 100 because each of the charging conductors 114 and 116 is electrically isolated. In the combination of the first and second measures, the test area of ​​each of the charging conductors 114 and 116 is limited by corresponding electrical isolation on both sides, thereby accurately monitoring the test area 111 until electrical isolation.

[0110] An alternative to opening this or these charging relays 108 is to define or limit the test area 111 (e.g., toward the charging station 100) by connecting or arranging a filter element 109 (e.g., a low-pass filter) on the output side of the charging relays 108 located on each of the charging conductors 114 and 116.

[0111] These filtering elements can be, for example, low-pass filter element 109. Low-pass filter element 109 may include ferrite. Figure 3 In this embodiment, the filter element 109 is implemented as a toroidal core or a clip-on ferrite, which is placed, for example, around the charging conductors 114 and 116.

[0112] The low-pass filter element 109 can have very low impedance to the charging current (e.g., DC charging current or low-frequency AC charging current). The frequency or spectrum of the test signal, which serves as the contact monitoring signal, is designed in such a way that the low-pass filter element 109 has high impedance to the test signal. In this way, any circuitry arranged behind the filter element 109 (e.g., in the charging station 100) from the perspective of the charging cable 110 will not affect the test signal.

[0113] In other words, if in Figure 3If a short circuit exists to the left of the filter element 109 (e.g., ferrite), this short circuit is excluded during measurement using the analysis unit 204 (i.e., it will not be detected by short circuit detection). The determination of contact refers only to contact between the filter element 109 and an unconnected or unplugged charging plug 112 in the test area 111. This characteristic is precisely what is desired, allowing the defined proportions to function, rather than allowing arbitrary wiring within the charging station 100 to impair the function of the device 200 (i.e., short circuit detection).

[0114] Furthermore, it may be advantageous to perform short-circuit monitoring only in exposed areas outside the charging station 100. Therefore, the filter element 109 can be placed, for example, as close as possible to the connection area of ​​the charging cable 110 inside the charging station 100.

[0115] Depending on the specific size, for example, a filter element 109 made of magnetic material may become saturated under high charging current, thus temporarily losing its filtering effect. Therefore, the control unit 102 is preferably adapted to implement or initiate short-circuit monitoring by means of the signal generator 202 and the analysis unit 204 when there is no charging current or no large charging current flowing through and the filter element 109 has no or no heavy load.

[0116] A short circuit occurring during the charging process can or should be disconnected as quickly as possible by a device other than device 200 (e.g., a fuse) so as not to cause destructive effects due to the short circuit during charging. For this application example (i.e., short circuit detection and safety shutdown during charging), device 200 may be optionally used.

[0117] Figure 4 This is a schematic block diagram of a fourth embodiment of a device 200 for monitoring contacts 212 between at least two charging conductors 114 and 116 used for charging an electric vehicle 150. This fourth embodiment can be implemented alone or as a further embodiment of the first, second, and / or third embodiments. Features indicated by the same reference numerals in different embodiments may be equivalent, interchangeable, or consistent.

[0118] In the fourth embodiment, the device 200 (i.e., the monitoring device) is implemented or placed in the charging station 100 (preferably as in the second embodiment). The device 200 includes a total of four or at least four filtering elements 109. For example, one filtering element 109 is arranged on each charging conductor 114 and 116 for limiting relative to the charging station 100 (e.g., on this or these charging relays 108) and relative to the electric vehicle 150 (e.g., in the charging plug 112).

[0119] In the fourth embodiment, even if the charging plug 112 is plugged into the electric vehicle 150 (i.e., plugged into the charging socket 154), the device 200 can determine whether contact exists (i.e., it can determine a defined state for the test area 111 to be monitored). Optionally, a filter element 109 or other filter element 109 for limiting relative to the electric vehicle 150 can be arranged in the electric vehicle 150.

[0120] Figure 5 This is a schematic block diagram illustrating one embodiment of the filter element 109. The filter element 109 can be used in any of the embodiments disclosed herein, preferably as a low-pass filter, high-pass filter, band-pass filter, or band-stop filter.

[0121] The filter element 109 includes an inductor 502, a capacitor 504, and a damping resistor 506. The filter element 109 can be connected in the charging conductors 114 and / or 116. For lower frequencies of the charging current, this inductor operates with low impedance, allowing (e.g., almost) the entire charging current to flow through the inductor 502. In this case, the potential loss resistance of the inductor must be kept low so that there is no significant loss during the charging process, thus preventing temperature rise. Alternatively, the inductor 502 can include a coil. As an alternative or supplementary solution, the wire inductance of the conductor segment of the charging conductors 114 or 116 can be used as the inductor.

[0122] Capacitor 504 and damping resistor 506 can be selected in a way that creates a band-stop at the frequency of the test signal (i.e., the short-circuit monitoring signal), meaning the total impedance of the filter element 109 is relatively large for the test signal (e.g., compared to the impedance of the charging current). This allows for the limitation (i.e., blocking) of the test signal, thereby enabling the defined test region 111 (i.e., the monitoring region).

[0123] This filtering element may include, for example, a parallel resonant circuit whose resonant frequency is the frequency of the test signal (i.e., the operating frequency or spectrum).

[0124] While ferrite and / or parallel resonant circuits are advantageous (e.g., compact, reliable and / or precisely adjustable) implementations of filter element 109, other solutions for implementing filter element 109 still exist.

[0125] As illustrated in the above exemplary embodiments, at least some embodiments can implement safety monitoring, such as determining whether there is contact between charging conductors 114 and 116 (i.e., detecting a short circuit), for example, by measuring in the charging cable 110 before the charging process is initiated. This allows for immediate detection of potential short circuits (e.g., caused by vandalism, such as someone pushing a conductive object like a paperclip into the contacts of the charging plug 112) and preferably reporting to the control unit 102 upon occurrence of a short circuit.

[0126] Monitoring is performed at a low voltage that poses no risk of contact, so there is no danger even in the event of an intentional short circuit, as the actual charging voltage has not yet been applied to any externally accessible contacts. Furthermore, optional electrical isolation via coupling element 206 enhances the overall system safety.

[0127] Although the invention has been described in conjunction with exemplary embodiments, it will be apparent to those skilled in the art that modifications can be made in different ways and equivalent solutions can be used as alternatives. Furthermore, numerous modifications can be made to adapt specific situations or materials to the technical principles of the invention. Therefore, the invention is not limited to the disclosed embodiments, but includes all embodiments falling within the scope of the appended claims.

[0128] Explanation of reference numerals in the attached figures

[0129] 100 charging stations

[0130] Power connector for 101 charging station

[0131] 102 Control Unit

[0132] 103 Signal conductors (such as PP or CP) or power supply conductors

[0133] 104 Modem of Control Unit

[0134] 106 charging power supply, with preferred power conversion unit

[0135] 107 Main Relay

[0136] 108 Charging Relay

[0137] 109 Filter Components

[0138] 110 charging cable

[0139] Test Area 111

[0140] 112 Charging cable plug

[0141] 113 Other components in the charging plug

[0142] 114 First charging conductor, such as the positive terminal

[0143] 116 Second charging conductor, such as the negative terminal

[0144] 118 Protective grounding conductor

[0145] 150 Electric Vehicle (EV)

[0146] 152 Vehicle control unit of electric vehicle

[0147] 154 Electric vehicle charging socket

[0148] 156 Electric vehicle power grid or traction energy storage device

[0149] 158 Electric Vehicle Modem

[0150] 200 Devices for monitoring contact

[0151] 201 Interface for the control unit of the charging station

[0152] 202 Signal Generator

[0153] 204 Analysis Unit

[0154] 205 Contact Monitoring Circuit

[0155] 206 Coupling element

[0156] 208 Input terminal of coupling element

[0157] 210 Output terminal of coupling element

[0158] 212 Contact or short circuit between charging conductors

Claims

1. A device (200) for monitoring the contact between charging conductors (114, 116) of a charging station (100) for charging an electric vehicle (150), comprising: A signal generator (202) is adapted to output alternating test signals at the charging conductors (114, 116); Analysis unit (204), the analysis unit is adapted to determine whether there is conductive contact between the charging conductors (114, 116) based on the test signal; as well as A coupling element (206) is connected between the signal generator (202) and the charging conductors (114, 116), the coupling element being adapted to output a test signal of the signal generator (202) at these charging conductors (114, 116); The analysis unit (204) is adapted to monitor changes in the signal applied to the coupling element (206) and, in the event of a change in the signal, determine the contact between the charging conductors (114, 116).

2. The apparatus (200) according to claim 1, wherein the test signal is a voltage signal.

3. The apparatus (200) according to claim 2, wherein the test signal is a voltage induced between the charging conductors (114, 116).

4. The apparatus (200) according to claim 2, wherein the test signal is a voltage between 10mV and 100mV, or between 3V and 24V, or between 12V and 50V.

5. The apparatus (200) according to claim 1 or 2, wherein the test signal is aperiodic or periodic.

6. The apparatus (200) according to claim 5, wherein the frequency of the test signal is less than 100MHz or 10MHz and / or greater than 1kHz or 10kHz, and / or wherein the wavelength of the test signal on the charging conductor (114, 116) is greater than the length of the charging conductor (114, 116).

7. The apparatus (200) according to claim 1, wherein the signal generator (202) includes an oscillation circuit.

8. The apparatus (200) according to claim 1, wherein the coupling element (206) electrically isolates the charging conductors (114, 116) from each other and / or electrically isolates the charging conductors (114, 116) from the signal generator (202).

9. The apparatus (200) according to claim 8, wherein the coupling element (206) capacitively and / or inductively couples the signal generator (202) to the charging conductors (114, 116) for outputting a test signal of the signal generator (202) at the charging conductors (114, 116), and / or the coupling element (206) includes an impedance circuit and / or a converter.

10. The apparatus (200) according to claim 1, wherein the apparatus (200) includes a control unit (102) or a control interface (201) connected to or capable of being connected to the control unit (102), and further wherein the analysis unit (204) is adapted to send a signal to the control unit (102) or at the control interface (201) indicating whether there is conductive contact between the charging conductors (114, 116).

11. The apparatus (200) according to claim 10, wherein the control unit (102) is adapted to output a fault state and / or interrupt the charging current passing through the charging conductors (114, 116) and / or de-energize the charging conductors (114, 116) in the presence of the contact.

12. The apparatus (200) according to claim 10 or 11, wherein the control unit (102) is adapted to Before outputting the test signal and / or determining whether there is contact between the charging conductors (114, 116), the charging conductors (114, 116) are electrically isolated from the charging power supply (106); and / or Without contact, the charging conductors (114, 116) are electrically connected to the charging power supply (106).

13. The apparatus (200) according to claim 12, wherein the charging power supply (106) includes a power conversion unit adapted to apply a charging current and / or a charging voltage to the charging conductors (114, 116) according to the control unit (102). The main relay (107), according to the control unit (102), can optionally electrically isolate and connect the charging power supply (106) to the power connector (101) in the open and closed states of the main relay (107); and / or The charging relay (108) can optionally electrically isolate and connect the charging power supply (106) to each of the charging conductors (114, 116) in the open and closed states of the control unit (102).

14. The apparatus (200) according to claim 1, wherein the test area (111) for monitoring the contact (212) between the charging conductors (114, 116) is limited by means of electrical isolation and / or by means of at least one frequency selective filter element (109).

15. The device (200) according to claim 14, wherein the electrical isolation is the open state of the charging relay (108).

16. The apparatus (200) according to claim 14, wherein the at least one frequency selective filter element (109) is arranged on the output side of the charging station (100) and / or the charging plug (112) in such a way that it is on each of the charging conductors (114, 116) respectively or together on the charging conductors (114, 116).

17. The apparatus (200) according to claim 16, wherein the at least one frequency selective filter element (109) is arranged on the output side of the charging relay (108).

18. The apparatus (200) according to claim 14 or 16, wherein the at least one frequency selective filter element (109) is respectively or jointly covered by ferrite with respect to the charging conductors (114, 116), and / or includes a parallel resonant circuit (502, 504) with a damping resistor (506), and / or includes a frequency selective component with an inductor and / or a capacitor with a damping resistor.

19. The apparatus (200) according to claim 10, wherein the control unit (102) is adapted to output a fault status of the charging cable (110) or the charging plug (112) before the signal conductor (103) of the charging cable (110) or the charging plug (112) sends a signal for the connection between the charging station (100) and the electric vehicle (150) in the presence of the contact, or to output a fault status of the electric vehicle (150) after the signal conductor (103) of the charging cable (110) or the charging plug (112) sends a signal for the connection between the charging station (100) and the electric vehicle (150).

20. The apparatus (200) of claim 1, wherein the analysis unit (204) is adapted to detect the voltage between the charging conductors (114, 116) constructed by the test signal and / or the current in the charging conductors (114, 116) driven by the test signal and to determine the impedance between the charging conductors (114, 116) based on the voltage and / or the current, wherein if the impedance is less than a threshold value of the impedance, the analysis unit (204) determines that the contact exists between the charging conductors (114, 116).

21. The apparatus (200) of claim 20, wherein the impedance is a numerical value of impedance or an active portion of impedance.

22. The apparatus (200) of claim 1, wherein the analysis unit (204) is adapted to detect attenuation of the test signal, wherein if the attenuation is greater than a threshold of impedance, the analysis unit (204) determines that the contact exists between the charging conductors (114, 116), or if the attenuation is less than the threshold of impedance, the analysis unit (204) determines that the contact exists between the charging conductors (114, 116).

23. A charging station (100) for charging an electric vehicle (150), comprising: Charging power supply (106); A charging relay (108) is adapted to optionally electrically isolate and connect the charging power supply (106) to the charging conductors (114, 116) of the charging cable (110) for charging the electric vehicle (150) in the open and closed states of the charging relay (108). The apparatus (200) for monitoring the contact between the charging conductors (114, 116) of the charging station (100) according to any one of claims 1 to 22; A control unit (102) is adapted to output a test signal at the charging conductors (114, 116) by means of a signal generator (202) of the device (200) when the charging relay (108) is open, and to determine, by means of an analysis unit (204), whether there is conductive contact between the charging conductors (114, 116) based on the test signal, wherein the control unit (102) is also adapted to output a fault status when the contact exists and / or to close the charging relay to charge the electric vehicle (150) when there is no contact.

24. A charging plug (112) for charging an electric vehicle (150), comprising: Charging conductors (114, 116) optionally electrically connected to the charging power supply (106) of the charging station (100) via a charging cable (110); and The apparatus (200) for monitoring the contact between the charging conductors (114, 116) of the charging station (100) according to any one of claims 1 to 22.

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