Method for insulation monitoring of an electrically operatable vehicle

Abstract

The invention relates to a method for monitoring the insulation of an electrically operable vehicle (1), the vehicle (1) having a first number of insulation monitors (32a-32i) and a second number of insulation stages (30a-30i), the insulation stages (30a-30i) each comprising at least one power electronic component and / or at least one power transmission component and / or at least one grounding component, the insulation monitors (32a-32i) being arranged in the first number of insulation monitors (32a-32i), and the insulation stages (30a-30i) being arranged in the second number of insulation stages (30a-30i). A suppression signal (I1) is output by a central control unit (34) of the vehicle (1) to a first group (G1) of a first number of insulation monitors in a first time period ([Delta] T1), the first group comprising at least one first insulation monitor (32a), the insulation monitors (32a, 32c-32i) of the first group (G1) are configured such that the insulation measurements (Ma) by the one or more insulation monitors (32a, 32c-32i) of the first group (G1) are completely stopped during a first time period ([delta] T1), and wherein the insulation monitors (32a, 32c-32i) of the first group (G1) are stopped during the first time period ([delta] T1). An insulation measurement (Mb) is at least temporarily performed on at least one insulation stage (30b) of the second number of insulation stages by means of at least one second insulation monitor (32b) that does not belong to the first group (G1).

Description

[0001] The invention relates to a method for insulation monitoring of an electrically operable vehicle, wherein the vehicle has a first number of insulation monitors and a second number of insulation stages, wherein the insulation stages each comprise at least one power electronic component and / or at least one current transmission component, and wherein insulation measurements are performed on at least one insulation stage of the second number of insulation stages by at least one insulation monitor of the first number of insulation monitors.

[0002] In electrically operable vehicles, in particular vehicles for operation on electrified roads, components of power electronics and control electronics are usually arranged on different insulation levels, which are insulated separately accordingly. In order to monitor the insulation levels, a plurality of monitoring devices, so-called insulation monitors, are usually installed in such vehicles. In this case, a test voltage is applied to the relevant insulation level by the insulation monitors in order to carry out insulation measurements.

[0003] However, if there are multiple insulation levels in the vehicle, which, for example, have more than one connection to the insulation monitor, the ranges of action of the individual insulation monitors may overlap and the insulation levels to which they are assigned may therefore overlap. These insulation monitors are assigned, for example, to a main battery, a DC transformer (or DC / DC regulator), different isolated grounding layers or (in overhead line vehicles) a pantograph (or pantograph collector) as the respective insulation level or circuit. The other insulation levels can here in particular be provided by other elements in the traction circuit of the vehicle.

[0004] If at least two insulation monitors carry out insulation measurements in succession (even simultaneously) without sufficient time for potential equalization after the application of the test voltage, the individual measurements can influence each other and can thus lead to malfunctions of the insulation monitors and thus to errors in the insulation monitoring. Depending on the set repetition frequency of the insulation measurements of the insulation monitors connected to the insulation level, errors or malfunctions can occur more or less frequently. Insulation monitors at the interface between original vehicle components and third-party components from other manufacturers (e.g. pantographs) are particularly susceptible to malfunctions, in particular because they can be assigned to different control units.

[0005] This can lead to erroneous measurement results, so-called "false positives". The presence of such false positive insulation faults has a negative impact on the availability of the vehicle, even though the fault recorded is only due to the fault in the insulation measurement and the vehicle can therefore continue to be operated safely, but the vehicle is often unable to continue operating due to the fault report.

[0006] The object of the present invention is therefore to provide a method by means of which insulation measurements can be carried out in an electrically operable vehicle having a plurality of insulation stages in a manner that is as trouble-free as possible.

[0007] The technical problem is provided according to the invention by a method for insulation monitoring of an electrically operable vehicle, the vehicle having a first number of insulation monitors and a second number of insulation stages, wherein the insulation stages each comprise at least one power electronic component and / or at least one power transmission component, and wherein an inhibition signal is output by a central control unit of the vehicle within a first time period to a first group of the first number of insulation monitors, the first group comprising at least one first insulation monitor, the central control unit being in particular configured to centrally control insulation measurements of the insulation stages.

[0008] According to the method, provision is made here that due to the suppression signal, insulation measurements by one or more insulation monitors of the first group are completely stopped during the first time period, and insulation measurements of at least one insulation stage of the second number of insulation stages are at least temporarily performed during the first time period by at least one second insulation monitor not belonging to the first group. Advantageous and partially independently inventive embodiments are the dependent claims and the technical solutions described below.

[0009] Electrically operable vehicles include in particular purely electrically operable vehicles, but also hybrid vehicles additionally having an internal combustion engine and / or a fuel cell. The electrical energy for the electrical operation of the vehicle can be provided in particular via overhead lines and / or at least partially via batteries.

[0010] Insulation monitoring includes, in particular, monitoring the insulation state of the relevant insulation level, for example, monitoring on the basis of an insulation resistance, which is preferably determined on the basis of a test voltage applied to the relevant insulation level.

[0011] The vehicle has a first number of insulation monitors which are each provided to carry out insulation measurements and / or to measure the insulation state, in particular the insulation resistance, for a limited area of ​​an electrical circuit in the vehicle, preferably for an insulation level.

[0012] Furthermore, the vehicle has a second number of insulation stages, wherein each insulation stage comprises at least one power electronic component and / or a power transmission component and / or a grounding component, in particular of a traction circuit. Such a power electronic component can be provided, for example, by a battery (as a main power source or power buffer) or a DC transformer; the power transmission component can also be provided, in particular, by a pantograph. The grounding component can be provided, in particular, by a metal component in the vehicle, for example a frame or the like. The second number can be different from or the same as the first number.

[0013] The central control unit can be provided in particular by a central control unit for all main vehicle functions of the vehicle, i.e. the vehicle has a central control unit for controlling the main functions, in particular the driving functions, which also outputs the inhibition signal in the method. However, the central control unit can also be provided by a control unit dedicated to the method, so that the control unit plays a central role only within the scope of the method according to the invention, while other main vehicle functions, in particular the driving functions, are controlled by one or more other control units.

[0014] In the first time period, the central control unit preferably outputs the inhibition signal to a first group of the first number of insulation monitors via one or more correspondingly adapted and configured interfaces, thereby outputting the inhibition signal to at least one first group of the first number of insulation monitors. The first group here has at least one first insulation monitor and can also have further insulation monitors or only the first insulation monitor.

[0015] The inhibition signal preferably represents a negative authorization, i.e. the insulation monitors of the first group are prohibited from performing insulation measurements within the first time period in which the inhibition signal is output. Due to the inhibition signal, the insulation measurements of the insulation monitors in the first group are completely stopped within the first time period. The stopping can be realized in particular by a separate control device, which is connected upstream of the individual insulation monitors and usually controls the corresponding insulation measurements of the insulation level (or its components) by the relevant insulation monitors. The control devices of the individual insulation monitors can be connected to the central control unit via corresponding interfaces in order to transmit the inhibition signal.

[0016] By “disabling” the insulation monitors in the divided first group from performing insulation measurement in the form of an inhibition signal, the insulation measurement in each insulation level monitored by the insulation monitors in the first group is stopped within the first time period.

[0017] The stopping of the insulation measurement triggered by the suppression signal can be used to ensure that a second insulation monitor which does not belong to the first group and is therefore not prevented from performing an insulation measurement by the suppression signal performs an insulation measurement at least temporarily within a first time period. The first group is preferably coordinated with the second insulation monitor in such a way that the first group includes those insulation monitors which are most likely to influence the second insulation monitor when performing insulation measurements simultaneously or in rapid succession (e.g. due to a lack of potential equalization between the insulation levels assigned to the relevant insulation monitors). The first group includes in particular all insulation monitors which are assigned to insulation levels adjacent to the insulation level assigned to the second insulation monitor.

[0018] When the second insulation monitor performs insulation measurement on the insulation level assigned to the second insulation monitor, it will not be interfered with or affected by the insulation monitor of the adjacent insulation level, thereby improving the reliability of the insulation measurement and, in particular, reducing false positives (for example, for resistance values ​​below the minimum resistance value), thereby significantly limiting unreasonable shutdowns of the train set.

[0019] Preferably, the suppression signal interrupts the insulation measurement being performed by the first insulation monitor on the assigned insulation level of the second number of insulation levels. In other words, the suppression signal not only causes no new insulation measurement to be started by the insulation monitors of the first group within the first time period, but also interrupts or terminates the insulation measurement being performed for the relevant insulation monitors. In this case, preferably all insulation measurements of the insulation monitors of the first group are terminated. For example, the termination can be achieved by the respective control devices of the corresponding insulation monitors. By immediately terminating the insulation measurement being performed, consistent conditions can be ensured with regard to potential equalization.

[0020] In an advantageous embodiment, the insulation measurement of the associated insulation level by the first insulation monitor is resumed after the suppression signal has ended. This means in particular that the insulation measurement originally performed by the first insulation monitor, which was interrupted at the beginning of the first time period due to the suppression signal, is continued or restarted after the end of the first time period and therefore after the suppression signal has ended. In particular, the insulation measurement can be preset as a "default" state in or for the control device of the corresponding insulation monitor, so that the insulation measurement is always performed when no suppression signal is received from the central control unit (via a corresponding interface).

[0021] Preferably, a monitoring voltage is applied to the insulation stages for the insulation measurement. This is understood in particular to mean that the monitoring voltage is applied to the corresponding components of the insulation stages (for example relative to ground or another reference potential). Depending on the design of the insulation monitor and the components of the insulation stages, the monitoring voltage is typically several 10s to several 100s of volts. This allows the ohmic resistance or the voltage drop to be determined and thus a reduced insulation resistance to be detected based on deviations from a nominal value or a theoretically determined value.

[0022] The first time period is preferably selected as a function of the time for potential equalization, which is carried out after the monitoring voltage is applied, and / or as a function of a minimum measurement duration for power electronics components or current transmission components for an insulation level, and / or as a function of a maximum permissible duration for which the first number or first group of insulation monitors do not carry out an insulation measurement for the respective insulation level. The first time period is therefore selected in particular at least to be long enough that the relative configuration of the insulation monitors of the first group allows potential equalization before the second insulation monitor carries out an insulation measurement for the relevant insulation level, and furthermore the minimum measurement duration for the components of the insulation level to be monitored by the second insulation monitor is observed. On the other hand, the first time period is preferably short enough that after the first time period has expired, a new insulation measurement can still be carried out in good time for the components of the insulation level monitored by the insulation monitors of the first group, without exceeding the maximum permissible duration for which no insulation measurement is carried out.

[0023] Advantageously, the suppression signal is output via a communication interface and / or to a control device, which is respectively assigned to the insulation monitors of the first group. This includes in particular the possibility that the suppression signal can be output directly to the individual insulation monitors by a central control unit with corresponding wiring, or that the suppression signal can be directly transmitted to the relevant insulation monitors or their control devices via a communication interface, in particular a communication interface at the individual insulation levels.

[0024] Preferably, the suppression signal is monitored in a control device of the relevant insulation monitors assigned to the first group. In particular, the control device controls the insulation measurement to be stopped or to be resumed within a first time period in accordance with the suppression signal. The control of the insulation measurement of the insulation level is differentiated into the actual insulation monitor and the control device is respectively connected upstream of the actual insulation monitor, which further reduces the fault susceptibility of the insulation measurement.

[0025] Advantageously, the inhibition signal is transmitted via a CAN bus of the vehicle, in particular from a central control unit of the vehicle to the corresponding insulation monitor, at least indirectly to an associated control device. The use of a CAN bus has the advantage that it is available in almost all modern vehicles. In addition, due to the operating principle of the CAN bus, the inhibition signal can be output via the CAN bus in such a way that the central control unit can implement the inhibition signal particularly easily, for example, in the context of the J1939 protocol, the character string "01" is output, while other character strings "00, 10, 11" have a significantly reduced error probability due to the combination of two bits. This reduces downtimes in driving operation due to errors in insulation measurement and corresponding measures.

[0026] It has also proven to be advantageous if, after the first time period has ended, in further time periods, suppression signals are output successively by the central control unit of the vehicle to further groups of the first number of insulation monitors, respectively, divided accordingly, wherein, due to the suppression signal, insulation measurements by one or more insulation monitors in the respective group are completely stopped in the relevant time period, and wherein, in the relevant time period, insulation measurements of at least one of the second number of insulation stages are at least temporarily performed by an insulation monitor not contained in the relevant group.

[0027] In other words, this includes, in particular, dividing the first number of insulation monitors into different groups, which may also partially overlap, but preferably no two groups completely overlap. Corresponding suppression signals are output successively to the insulation monitors of the respective groups, so that insulation measurements can be carried out by the insulation monitors outside the relevant group in the corresponding time period of the relevant suppression signal.

[0028] By correspondingly selecting the groupings, individual insulation levels that are relevant for operation can therefore be checked successively by means of corresponding insulation monitors.

[0029] Advantageously, by periodically sequencing the plurality of time periods and performing corresponding insulation measurements or stopping the insulation measurements for the divided plurality of groups, a monitoring interval is defined for at least some, preferably each, of the first number of insulation monitors, wherein the monitoring interval is in particular given by a predefined time period during which the insulation monitor does not perform insulation measurements. Thus, by correspondingly adapting the monitoring interval, individual insulation levels can be checked by the method without exceeding or falling below safety limits.

[0030] Preferably, the plurality of time periods are selected for the periodic ordering of the divided plurality of groups so that an insulation level classified as safety-critical has a shorter monitoring interval than an insulation level not classified as safety-critical. An insulation level is classified as safety-critical if there is a higher risk of contact or a higher risk of first failure for the relevant components of the insulation level.

[0031] Advantageously, the periodic ordering of the time periods is selected for the divided multiple groups according to the operating mode and / or operating information of the vehicle. This can be done differently for different insulation levels, so that correspondingly different monitoring intervals are generated. The operating mode can be, for example, driving on the overhead line or opening the doors for passengers to get on and off the vehicle while the vehicle remains connected to the overhead line. In this case, insulation measurements can be made more frequently for the insulation levels in the door area. The operating information can include, in particular, the vehicle speed, so that the insulation properties can be checked more frequently for specific components and the associated insulation levels, especially in the traction circuit.

[0032] The present invention also discloses an electrically operable vehicle, comprising: a first number of insulation monitors and a second number of insulation stages, wherein the insulation stages each comprise at least one power electronic component and / or a power transmission component, and the vehicle further comprises a central control unit, wherein the vehicle is configured to implement the aforementioned method.

[0033] The vehicle according to the invention has the same advantages as the method according to the invention. The advantages of the method and its developments can be substantially transferred to the electrically operated vehicle.

[0034] Embodiments of the present invention are described in more detail below with the aid of the accompanying drawings. In the accompanying drawings:

[0035] Figure 1 A schematic side view of an electrically operable vehicle is shown, and

[0036] Figure 2 Schematically showing the Figure 1 A flow chart of a method for insulation monitoring of a vehicle.

[0037] Parts and dimensions that correspond to one another are provided with the same reference symbols in all figures.

[0038] The figure schematically shows an electrically operable vehicle 1 in a side view, which is designed as a trolleybus 2. Other designs are also conceivable, such as a tram or other vehicle, especially a vehicle powered by an overhead line. The vehicle can also have an internal combustion engine or a similar device (not shown) for auxiliary or emergency purposes. The vehicle 1 is powered by an overhead line 4 for electrical operation. For this purpose, the vehicle 1 has a pantograph 6 (also commonly called a pantograph), which is pressed against the overhead line 4 during operation, especially during driving, by a spring mechanism not shown in detail, so that an electrical contact is established between the pantograph 6 and the overhead line 4, and thus the transmission of electrical power to the vehicle 1 is achieved. In the embodiment described, the pantograph 6 is electrically connected to a first DC transformer 10 arranged in the vehicle 1 (it is assumed here that there is a DC voltage in the overhead line 4; if there is an AC voltage in the overhead line 4, which is not shown, a rectifier is used instead).

[0039] The first DC transformer 10 is electrically connected to a plurality of electric motors 12, which are respectively arranged at the wheels 14 (or axles) of the vehicle 1 and drive the corresponding wheels 14 (or the corresponding axles). To this end, the first DC transformer 10 converts the DC supply voltage at the overhead line 4 into an operating voltage set or optimal for the corresponding electric motor 12. Each wheel 14 of the vehicle 1 may have its own assigned electric motor 12, or the electric motor 12 may drive each wheel group of the wheel 14 (for example, wheels on the same axle, or wheels on multiple axles in the case of a transmission), or the electric motor 12 may not drive each individual wheel 4. The electric motor 12 constitutes the primary load of the electric power provided to the vehicle 1 via the overhead line 4.

[0040] In addition, the vehicle 1 also has a plurality of secondary loads 16, which include, by way of example and not exhaustively, a fan 18 for cooling power electronic components, a temperature control device 20 (which includes a heating device and an air conditioning device not shown in detail), a lighting device 22, and on-board electronic devices 24, wherein the on-board electronic devices include, in particular, an automatic control device and a regulating device for the electric motor 12 and an electronic device for processing control instructions for the driver to control the vehicle 1. The secondary loads 16 are also electrically connected to the first DC transformer 10 and draw power via the DC transformer. In this case, an additional DC transformer can be connected in front of some of the secondary loads 16 in order to adjust the voltage output by the first DC transformer 10 and designed to operate the electric motor 12 to the operating voltage of the corresponding secondary load 16. However, this is not necessary in the case of a DC transformer. Figure 1 In FIG. 1 , only the onboard electronics 24 are schematically shown, upstream of which a second DC converter 26 is provided, wherein any further DC converters associated with the secondary loads 16 are not shown.

[0041] The first DC converter 10 additionally supplies power to a battery 28 of the vehicle 1. The battery 28 is designed and provided to supply power to the electric motor 12 in the event of a failure of the external energy supply (eg, a voltage drop due to external reasons or a power failure of the overhead line 4).

[0042] In order to achieve safe operation of the vehicle 1, the electric motor 12, the first DC transformer 10, the secondary loads 16 (and the second DC transformer 26), and the battery 28 as primary loads are respectively assigned individual insulation levels 30a to 30i, which should ensure that the relevant components of the insulation level are electrically insulated from other components and away from the technically specified power flow. The individual insulation levels 30a to 30i are introduced here to ensure that no danger to people occurs when a possible fault occurs, such as when an electrical connection is made to a power transmission component.

[0043] In order to ensure the above-mentioned insulation, in particular to prevent the resistance of each insulation level 30a to 30i from falling below the minimum resistance, there are respective insulation monitors 32a to 32i on these insulation levels, which are respectively provided by measuring devices for the above-mentioned resistance and perform insulation measurement on the relevant insulation levels 30a to 30i by correspondingly applied test voltages (in other words, monitoring voltages).

[0044] It may happen that, for technical reasons, a certain insulation monitor 32a to 32i (especially temporary or switchable or permanent) must check two insulation levels (not shown) of the insulation levels 30a to 30i. In addition, the insulation measurements performed at the individual insulation levels 30a to 30i (especially directly "adjacent" insulation levels) may influence each other due to the incomplete balance of the potentials of the test voltages applied in each insulation level, so that the individual insulation measurements may erroneously measure too low a resistance and thus measure insufficient insulation for their insulation level 30a to 30i. Therefore, although this is not actually necessary for technical reasons, safety measures may be taken due to incorrect and unreasonable insulation measurements, so that the vehicle 1 may be temporarily stopped or even completely stopped.

[0045] Therefore, in Figure 2 The block diagram schematically shows a method for Figure 1 The method flow of performing insulation monitoring on a vehicle 1 is shown. The vehicle 1 has a plurality of insulation levels 30a to 30i, and insulation monitors 32a to 32i are respectively assigned to these insulation levels, and the insulation monitors are arranged and designed to perform insulation measurements at the respective insulation levels 30a to 30i by applying corresponding test voltages. In order to prevent the aforementioned mutual influence between different insulation measurements, a suppression signal I1 (dashed line) is outputted by a central control unit 34 of the vehicle 1 to a first group G1 of the insulation monitors 32a to 32i via corresponding communication interfaces 36a to 36i within a first time period ΔT1. The communication interfaces 36a to 36i can be designed as part of a CAN bus, for example.

[0046] The first insulation monitor 32a in the first group G1 performs insulation measurement Ma at the assigned insulation level 30a until the start of the first time period ΔT1 (dash-dotted line). At the start of the first time period ΔT1, the other insulation monitors 32c to 32i of the first group G1 can also perform corresponding insulation measurements (not shown) at the associated insulation levels 30c to 30i. The suppression signal I1 is not received directly by the first insulation monitor 32a, but by a control device 38a assigned to the first insulation monitor 32a and controlling its insulation measurement.

[0047] Due to the reception of the suppression signal I1 via the communication interface 36a, the control device 38a interrupts the insulation measurement Ma of the first insulation monitor 32a. The same applies to all other insulation monitors 32c to 32i of the first group G1, or their control devices 38a, 38c-38i, so that the insulation monitors 32c to 32i of the first group G1 stop all insulation measurements at the beginning of the first time period ΔT1 (not shown).

[0048] After a short time Ta for potential equalization of the test voltage of the insulation measurement just completed, the second insulation monitor 32b not belonging to the first group G1 starts insulation measurement Mb at the insulation level 30b assigned to it by applying a corresponding test voltage (dash-dotted line).

[0049] Since the insulation monitors 32a, 32c of the adjacent insulation levels 30a and 30c (i.e. possibly suitable for creepage currents or leakage currents) do not now perform any insulation measurements, the insulation measurement Mb of the second insulation monitor 32b can be carried out without influencing the insulation measurement Ma (and possible other insulation measurements of the insulation monitors 32c to 32i of the first group G1), also due to the potential balancing that took place during the balancing time Ta.

[0050] At the end of the first time period ΔT1, the inhibition signal I1 of the first group G1 of the insulation monitors 32a, 32c to 32i also stops. During the second time period ΔT2, the central control unit 34 outputs an inhibition signal I2 (dotted line) to the second group G2 of the insulation monitors 32b to 32i (or the associated control devices 38b to 38i) in a similar manner, so that during this second time period ΔT2, no insulation measurement is performed at the corresponding insulation level 30b to 30i by the insulation monitors 32b to 32i of the second group G2. After a short balancing time Tb for potential balancing, insulation measurement can be performed at the associated insulation level by the insulation monitors that do not belong to the second group G2 with the aid of the corresponding test voltage. In this case, the first insulation monitor 32a can in particular resume the insulation measurement Ma (not shown) at the insulation level 30a.

[0051] In this way, insulation measurements can be performed successively for all insulation levels 30a to 30i, wherein the respective groups of these insulation levels are formed in such a way that the insulation monitors respectively remaining outside the relevant group can perform insulation measurements without being influenced by other insulation monitors. In other words, the groups are configured such that, for a specific insulation monitor that is to perform insulation measurements in a specific time period, all other insulation monitors that may influence the specific insulation monitor during insulation measurement are defined as part of the assigned group and therefore do not perform insulation measurements due to the suppression signal.

[0052] By means of a sequence of suppression signals and corresponding time periods in which no insulation measurement is performed, and by means of assigning certain insulation monitors to different groups of insulation monitors which in each case receive suppression signals and therefore do not perform insulation measurements, it is possible to define monitoring intervals (not shown) for each individual insulation monitor as the entire time period in which no insulation measurement is performed by the relevant insulation monitor. These monitoring intervals can also be preset in order to define the time periods and the assigned groups of insulation monitors which are to receive suppression signals in each case. The preset can be made dynamically, for example, depending on the driving speed, whether a door is open (in which case the monitoring intervals of the insulation level including components in the vicinity of the door are preferably shortened) or whether a component is generally safety-relevant (in which case the monitoring intervals of the assigned insulation level are also preferably selected to be shorter than the insulation levels of components which are not safety-relevant).

[0053] Although the details of the present invention have been illustrated and described in detail through preferred embodiments, the present invention is not limited to the disclosed examples, and those skilled in the art may derive other different variants therefrom without departing from the scope of protection of the present invention.

[0054] Reference numerals list

[0055] 1 Vehicle (electrically operated)

[0056] 2 Trolleybus

[0057] 4 Overhead lines

[0058] 6 Pantograph

[0059] 10. First DC Transformer

[0060] 12 Electric Motor

[0061] 14 Wheels

[0062] 16 Secondary load

[0063] 18 Fan

[0064] 20 Temperature control device

[0065] 22 lighting fixtures

[0066] 24 Vehicle Electronic Devices

[0067] 26 Second DC transformer

[0068] 28 Batteries

[0069] 30a-30i insulation class

[0070] 32a-32i Insulation Monitors

[0071] 32a, 32b First or second insulation monitor

[0072] 34 Central Control Unit

[0073] 38a-38i Control Device

[0074] G1, G2 First or second group

[0075] I1, I2 inhibition signal

[0076] Ma, Mb insulation measurement

[0077] Ta, Tb balance time

[0078] ΔT1 First time period

[0079] ΔT2 Second time period

Claims

1. A method for insulation monitoring of an electrically operable vehicle (1), wherein: The vehicle (1) has a first number of insulation monitors (32a-32i) and a second number of insulation stages (30a-30i), wherein the insulation stages (30a-30i) each include at least one power electronic component and / or at least one power transmission component and / or at least one grounding component, - wherein, in a first time period (ΔT1), a suppression signal (I1) is output by a central control unit (34) of the vehicle (1) to a first group (G1) of a first number of insulation monitors, the first group comprising at least one first insulation monitor (32a), - wherein, due to the suppression signal (I1), insulation measurements (Ma) performed by one or more insulation monitors (32a, 32c-32i) of the first group (G1) during the first time period (ΔT1) are completely stopped, - and wherein, during the first time period (ΔT1), an insulation measurement (Mb) is at least temporarily performed on at least one insulation stage (30b) of the second number of insulation stages by at least one second insulation monitor (32b) not belonging to the first group (G1).

2. The method according to claim 1, wherein: The suppression signal (I1) interrupts the insulation measurement being performed by the first insulation monitor (32a) on the associated insulation stage (30a) of the second number of insulation stages.

3. The method according to claim 1 or 2, wherein: After the suppression signal (I1) has ceased, the insulation measurement (Ma) of the associated insulation level (30a) by the first insulation monitor (32a) is resumed.

4. The method according to any one of the preceding claims, wherein: Monitoring voltages are applied to these insulation levels (30a-30i) to perform insulation measurements (Ma, Mb).

5. The method according to claim 4, wherein: The first time period (ΔT1) is selected according to the following aspects, namely, - the time for potential equilibration, which is carried out after application of the monitoring voltage, and / or - minimum measurement duration for power electronic components or power transmission components for insulation classes (30a-30i), and / or a maximum permissible duration during which the first number of insulation monitors do not carry out insulation measurements on the respective insulation level ( 30 a - 30 i ).

6. The method according to any one of the preceding claims, wherein: The suppression signal (I1) is output via a communication interface (36a-36i) and / or to a control device (38a, 38c-38i), which are respectively assigned to the insulation monitors (30a, 30c-30i) of the first group (G1).

7. The method according to claim 6, wherein: The damping signal (I1) is monitored in a control unit (30a, 30c-38i) of the associated insulation monitor (30a, 30c-30i) assigned to the first group (G1).

8. The method according to claim 6 or 7, wherein: The inhibition signal (I1) is transmitted via the CAN bus of the vehicle (1).

9. The method according to any one of the preceding claims, in, After the first time period (ΔT1) has ended, in a further time period (ΔT2), the central control unit (34) of the vehicle (1) successively outputs the inhibition signal (I2) to the correspondingly divided further groups (G2) of the first number of insulation monitors, wherein, due to the suppression signal (I2), insulation measurements (Mb) performed by one or more insulation monitors (32b) in the corresponding group (G2) are completely stopped within the relevant time period (ΔT2), And wherein, during the relevant time period (ΔT2), an insulation measurement (Ma) is at least temporarily performed on at least one insulation stage (30a) of the second number of insulation stages by an insulation monitor (32a) not contained in the relevant group (G2).

10. The method according to claim 9, wherein: By periodically sequencing the plurality of time periods (ΔT1, ΔT2) and performing corresponding insulation measurements (M1, Mb) on the divided plurality of groups (G1, G2) or stopping the insulation measurements, monitoring intervals are defined for at least some of the first number of insulation monitors (32a-32i).

11. The method according to claim 10, wherein: The plurality of time periods are selected for the periodic ordering of the divided plurality of groups such that the insulation levels (30a-30i) classified as safety-critical have shorter monitoring intervals than the insulation levels (30a-30i) not classified as safety-critical.

12. The method according to claim 10 or 11, wherein: The periodic ordering of the time periods is selected for the divided plurality of groups (G1, G2) according to the operating mode and / or operating information of the vehicle (1).

13. An electrically operable vehicle (1), comprising: - a first number of insulation monitors (32a-32i), - a second number of insulation levels (30a-30i), wherein each insulation level (30a-30i) comprises at least one power electronic component and / or power transmission component, and - a central control unit (34), The vehicle (1) is designed to carry out a method according to one of the preceding claims.

Images