Test field with safe power-off of dc voltage ports

Abstract

The invention relates to a test field with safe power-off of DC voltage ports. A test field for a test object has an energy source and a test station connected to the energy source via a DC voltage bus, the test station having a DC voltage port for the test object, and comprising: a resonant converter having a transformer; a PWM generator for supplying a PWM signal generated by the DC voltage at the DC voltage bus to the primary side of the transformer when supplied with an operating voltage; and a switch arranged between the transformer and the DC voltage port so as to interrupt the electrical connection; the test field comprises a safety control part so as to cut off the PWM generator from the operating voltage and open the switch in the protection state. In a room layout system having at least two rooms and a test field, the test field is distributed in the at least two rooms in the room layout system such that a DC voltage port is arranged in a first room and at least a portion of the rest of the test field is arranged in a second room.

Description

Technical Field

[0001] This invention relates to a test range. The test range discussed herein is used to perform electrical tests on a test object (e.g., an electric drive or power battery of an electric vehicle) at relatively high power at DC voltages in the tens of kilowatts range. Multiple test stations are connected to, or can be connected to, any one of the test objects at the test range. Here, the test object can receive electrical power from and / or send electrical power to the test station. Background Technology

[0002] As known from WO 2021 / 174278 A1, test benches for electric operation typically include converter assemblies with multiple converters, whether used for testing the drive systems, mechanical components (such as transmissions), or battery storage devices of electric vehicles, hybrid vehicles, or conventional vehicles with internal combustion engine motors. In particular, testing of battery storage devices is often performed in parallel, where multiple battery cells, battery modules, or battery packs are tested simultaneously using converters arranged in parallel. Summary of the Invention

[0003] The objective of this invention is to propose improvements for testing grounds.

[0004] This task is accomplished using the test field described in claim 1. Preferred or advantageous embodiments of the invention, as well as other inventive scope, are derived from the additional claims, the following description, and the accompanying drawings.

[0005] A test chamber is a test chamber used for testing or connecting to an object under test (DUT). Test chambers are used to perform electrical tests on DUTs. DUTs are tested using current to be fed into and / or drawn from them. The specifications of the test chamber are determined to enable the DUT to withstand relatively high electrical power. The test chamber is designed to apply relatively high electrical power to the DUT. The typical rated / maximum electrical power for each DUT is 250kW to 1MW, the rated voltage is typically about 200V to 800V, and the rated current is typically 1000A to 2000A.

[0006] The test field includes a DC voltage bus for guiding DC voltage.

[0007] The test field contains at least one energy source. The energy source can supply electrical power to the rest of the test field and, if necessary, can also receive electrical power from the rest of the test field. Therefore, the terms "source / generator / etc." here should be interpreted broadly: for example, the "energy source" here may be designed bidirectionally if necessary, and may also function as an energy sink when needed.

[0008] Each energy source has a first DC voltage interface to send power to the DC voltage bus under DC voltage, and in particular, to receive power.

[0009] The test field also includes multiple test stations. Each test station is used to test or connect one object under test.

[0010] Each test station has a second DC voltage interface for the DC voltage bus. Each test station also has a DC voltage port. This DC voltage port is used to connect to its respective object under test.

[0011] In the test field, all test stations are connected to the DC voltage bus via their second DC voltage interface. All energy sources are also connected to the DC voltage bus via their first DC voltage interface. Therefore, all energy sources and test stations are electrically connected to each other via the DC voltage bus and can exchange energy with each other using DC voltage.

[0012] Each test station contains a resonant converter. Each resonant converter contains a transformer, which has a primary side and a secondary side. The primary side faces or is electrically connected to a second DC voltage interface, and the secondary side corresponds to a DC voltage port.

[0013] Each test station includes a PWM generator. This PWM generator is configured to supply a PWM signal generated by the DC voltage at the second DC voltage interface to the transformer's primary side. However, the PWM generator only performs this function when an operating voltage is supplied. Without an operating voltage, the PWM generator cannot generate a PWM signal. Therefore, the transformer will either not bear a DC voltage or, if absolutely necessary, bear a DC voltage. However, no energy is transferred from the primary side to the secondary side. Therefore, no voltage is generated on the secondary side, and no power is generated. Consequently, no voltage is generated at the DC voltage port. Therefore, the DC voltage port is switched to a no-voltage state.

[0014] Each test station also includes a switch arranged or connected between the secondary side of the transformer and the DC voltage port of the test station. This switch is particularly located in the DC voltage path of the test station. The switch is at least unipolar, and more particularly bipolar. The switch is used to interrupt or establish the electrical connection between the secondary side and the DC voltage port, depending on whether the switch is open or closed. When the switch is open, additional protection (in addition to the aforementioned interruption of the operating voltage) is established to switch the DC voltage port to a voltage-free state.

[0015] The test site includes a safety control unit, specifically, each test station includes a safety control unit. This safety control unit is configured to selectively be in a protected state or switch to a protected state. The protection state of each test station can be individually activated or deactivated. In the protected state, the safety control unit is configured to take the following actions regarding the test station or a selected test station (for which the protection state is active): In the protected state, the safety control unit disconnects the PWM generator in the relevant test station from the operating voltage and keeps the PWM generator disconnected. Furthermore, the safety control unit also disconnects the switch in the relevant test station and keeps the switch in the open state.

[0016] In other words, the safety control unit ensures that the PWM generator is no longer supplied with operating voltage in the protected state at the relevant test station, and therefore no longer generates PWM signals to supply the transformer. This prevents power transfer via the transformer. Furthermore, the safety control unit also disconnects the electrical connection between the transformer, or rather, the secondary side of the transformer, and the DC voltage port at the relevant test station. As a result, the DC voltage port at the relevant test station is in a state of no voltage and no power.

[0017] Conversely, if the protection device in one or more of the test stations is operating in normal mode instead of safety mode, the protection device establishes an operating voltage to the PWM generator so that the PWM generator can generate a PWM signal and close the switch, thereby providing an electrical connection between the transformer and the DC voltage port. Thus, the test station can be used to test the object under test.

[0018] These measures ensure that, under protected conditions, electrical isolation is provided between the primary and secondary sides of the transformer, which is in a stopped (electrically isolated) state. Therefore, the DC voltage port is connected to the transformer only "up to the secondary side," and is electrically isolated from the rest of the test area (primary side, intermediate circuit / DC voltage bus, power source). Furthermore, as a second level of safety or in a redundant manner, the electrical connection between the secondary side and the DC voltage port is also interrupted by a switch.

[0019] Therefore, although the test site itself may remain operational and thus any remaining unprotected DC voltage ports may still be used to test the test object, safe operations can be performed at these DC voltage ports since they have been switched to a voltage-free state.

[0020] In some cases, test equipment, such as a so-called DC (direct current) box, is first connected to the output of the test station. Only at this test equipment can the actual object under test (DUT) be connected / connected. The DC box (e.g., in the form of a switch cabinet) is fixedly connected to the output of the test station. Strictly speaking, the treatment of the pilot voltage section requiring safety protection occurs at the output of the DC box. In this respect, the term "DC voltage port" should be interpreted broadly and can also refer to a port downstream of the test station. However, the relevant statements still apply in their intended meaning. From another perspective, the test equipment can also be understood as part of the test station. In this case, the test station terminates at the output of the test equipment with a DC voltage port, and the "object under test" to be connected there is simplified to the DUT.

[0021] In a preferred embodiment, the switch is neither a Trennschalter nor a Lasttrennschalter. These terms should be understood in their strictly technical sense, for example, see the web pages accessed on January 16, 2025: https: / / de.wikipedia.org / wiki / Trennschalter and https: / / de.wikipedia.org / wiki / Lasttrennschalter. Therefore, the expensive, complex, and bulky disconnecting switch can be eliminated due to the protective design.

[0022] In a preferred variant of this implementation, the switch is a contactor ( The term should also be understood in a strictly technical sense, for example, see the webpage accessed on January 16, 2025: https: / / de.wikipedia.org / wiki / Sch%C3%BCtz_(Schalter). Based on the safety design according to the invention, relatively inexpensive, uncomplicated, and small contactors can also be used to safely disconnect DC voltage ports, since the contactor is incorporated into the safety design only as a redundant element, aside from stopping the transformer.

[0023] In a preferred embodiment, the safety control unit includes a protective device configured to protect the test station from reconnection of the operating voltage at the PWM generator of the relevant test station and from re-closing the switch. This ensures that the PWM generator is not accidentally activated or the switch is closed, thus eliminating the risk to personnel working at the DC voltage port of the relevant test station. Therefore, (after power is cut off to the DC voltage port) the safety of preventing the DC voltage port from being reconnected can be ensured in a professionally common manner. Thus, work at the DC voltage port can be carried out without risk. The protective device is, for example, a fastening device with a padlock installed to prevent the disconnect switch from being re-closed.

[0024] In a preferred embodiment, the test field includes at least one operating element. This operating element is configured to activate a protective state in the safety control unit with respect to at least one of the test stations. In other words, the operating element drives the safety control unit to disconnect the operating voltage and switch. The operating element is arranged at a DC voltage port. "Arranged at a DC voltage port" is understood to mean that the operating element is arranged with a specific distance radius from the associated DC voltage port, for example, within a distance of at most 30 cm, 50 cm, 100 cm, 2 m, or 5 m. Therefore, there is a local correlation between the DC voltage port and the operating element. The operator can thus visually identify that the operating element is associated with the corresponding DC voltage port in order to de-energize that DC voltage port. It is particularly conceivable that, with respect to multiple or all DC voltage ports, the operating element is arranged closer to the DC voltage port to which it is associated than to all other DC voltage ports.

[0025] In a preferred variant of this embodiment, the operating element is a remote control unit for use with a safety control unit located away from it. In other words, it is possible or provided that the operating element is installed remotely from the safety control unit so that the DC voltage port can be switched to or ensured to be in a voltage-free state from there. Therefore, it is possible to arrange the safety control unit remotely from the operating element, for example, near a PWM control unit, transformer, or switch. This is even when the DC voltage port is relatively far from the PWM control unit / transformer / switch, for example, located in different rooms of a building or a room layout system with several rooms.

[0026] In a preferred embodiment, the DC voltage port is connected to the rest of the test station via a power supply line and is located away from the rest of the test station. Thus, the rest of the test station may be located, for example, in a first room of the building / room layout system, while the DC voltage port may be located in another room. For example, the rest of the test station may be located in a specially cooled power supply room along with the generator, while the DC voltage port is located in the test room of the object under test.

[0027] In a preferred embodiment, the object under test (DUT) is not or cannot be connected to the DC voltage port via a plug connector. Especially for the high-power testing of the DUT currently under consideration, a reliable high-power electrical connection must exist between the DC voltage port and the DUT. This can be reliably achieved by eliminating the plug connector. The connection is achieved, for example, through direct contact / rail-based assembly. However, due to the safety design for de-energizing the DC voltage port, safe handling can be achieved during preparation, for example, on the rail, even without a plug connector.

[0028] In a preferred embodiment, the test station includes a monitoring unit. The monitoring unit includes an output unit. The output unit is located at a DC voltage port. The above description of the operating element also applies to the meaning of "located at a DC voltage port." The monitoring unit is configured to monitor, in a protected state, whether the PWM generator is actually not being supplied with operating voltage at the relevant test station, and whether the electrical connection via a switch between the secondary side of the transformer and the DC voltage port is actually disconnected. If at least one of these conditions is not met, the monitoring unit is configured to provide or output an alarm to the output unit. In this case, for safety reasons, the monitoring unit also prevents the test station from being reconnected. Therefore, safe disconnection is ensured even in the event of a single fault.

[0029] In a preferred variant of this implementation, the test field, particularly the monitoring unit, includes a (self)diagnostic unit. This self-diagnostic unit is associated with the monitoring unit and configured to perform (self)diagnostic checks on the functionality of the monitoring unit. This diagnosis is particularly based on monitoring the intermediate circuit voltage that occurs at the transformer output and is fed into the step-down regulator during operation. Specifically, the discharge of this voltage over a specific maximum time period is examined.

[0030] If the functionality is not confirmed or is not verified based on the diagnostic results, the diagnostic unit is configured to place the test range in a persistent fault state. "Persistent" means that the fault state cannot be reset from within the test range. This type of fault state can only be reset from outside the test range via special means (e.g., by service technicians). This provides a further level of security that also covers the failure of the monitoring unit.

[0031] The objective of this invention is also achieved by the room layout system according to claim 11.

[0032] The room layout system includes at least two rooms and a test field according to the invention. The test field is arranged in at least two of the rooms in the room layout system, such that a DC voltage port is located in a first room, while at least a portion of the remaining parts of the test field are located in other, second rooms within those rooms.

[0033] As described above, in particular, the operating element is arranged in the first room, that is, as a remote control unit for a security control unit arranged at least partially in other rooms.

[0034] As described above, in particular, the DC voltage port located in the first room is connected via a power supply line to the remainder of the test station, which is at least partially located in other rooms.

[0035] This room layout system allows for modular and advantageous construction of the entire test range, enabling portions of the test range to be housed in dedicated rooms. For example, individual rooms can be cooled, ventilated, or heated. Access to each room can also be restricted to specific personnel / groups (maintenance technicians / operators / inspection personnel).

[0036] This invention is based on the following understanding, observations, and considerations, and also has the following preferred embodiments. For simplicity, these embodiments are sometimes referred to as "this invention." These embodiments may also include, or correspond to, the embodiments described above, and / or incorporate implementations not mentioned to date.

[0037] According to the present invention, a safe power-off is achieved to the DC voltage source (DC voltage port).

[0038] The combination of safe isolation achieved by means of transformers and redundant disconnection achieved by means of switches (especially DC contactors) results in safe power outages that can be remotely controlled.

[0039] It is known in practice that power outages via the main AC switch of the entire facility, i.e., the test site (e.g., at the energy source), are cumbersome if necessary, or that disconnecting the DC output is unsafe. The present invention achieves a safety standard for power outages, particularly those that can be remotely controlled. Consequently, power outages can be performed directly at the connection point via a remote control unit.

[0040] This invention relates to facilities / topologies under consideration that are highly dynamic, regenerative DC voltage sources and DC voltage sinks (test stations) for testing electrical components (objects under test) and for simulating batteries and other electrical storage devices in a test bench (test module). Typical objects under test are drive components and storage assemblies such as batteries, electric drives, converters, fuel cells, solar cells, or supercapacitors.

[0041] In the topology under consideration, high DC power (typically 250kW to 1MW) is provided from the lead-out bus (DC voltage port) under high voltage (up to 1500V) and high current (up to 2000A) conditions.

[0042] Here, one or more test stations can be connected to an energy source.

[0043] This invention is based on the following understanding:

[0044] During setup (changing the device under test, especially when changing the DUT at the test equipment), work must be done at the test station's lead-out busbar (DC voltage port, or the test equipment's output if necessary, see above) to allow direct contact with the DUT at the busbar. Using plug connectors under high current and high voltage conditions is very cumbersome, or only allows for limited use, or is even completely unusable.

[0045] Therefore, it is necessary to touch live parts (parts that may be conducting dangerous voltages) during this preparation process. Therefore, measures must be taken to ensure protection against electric shock during the preparation process.

[0046] The basic rules for preventing electric shock are as follows: • Accidental contact with the part that is conducting voltage must be prevented. This is not possible here because the busbar must be kept exposed for contact. • Touchable parts must not carry dangerous voltages. Therefore, it is essential to ensure that there is no voltage.

[0047] In practice, ensuring no voltage is achieved by adhering to safety rules. Two key points are crucial in this discussion: disabling power and preventing reconnection. This requires safety isolation, which can be established, for example, through switching devices such as power switches, load disconnectors, and fuse-type load disconnectors.

[0048] This leads to the following problems at present:

[0049] In the current topology, this is equivalent to shutting off the grid isolation device (main switch) in the energy source and ensuring safety. However, this has the following drawbacks: • If the facilities (test site) are installed in multiple rooms (which is often the case), the main switch may be located in a distant room. • The assignment between the work location (the location of the DC voltage port, the object under test, or the test equipment) and the power grid disconnect switch (the location of the power grid disconnect switch) must be established through drawings or markings, and the installers must rely on these drawings or markings. • There is no intuitive connection between the isolation location (the location of the power grid isolation device) and the working location (the location of the DC voltage port, the object under test, or the test equipment). • Shutting down work requires multiple round trips, which may lead to an avoidance response due to inconvenience. • The power source may be supplying power to other test benches (other test stations) on the same DC intermediate circuit (DC voltage bus), which may need to remain operational during assembly. In this case, the main switch of the power source cannot be turned off. This can create organizational and management challenges for installers, potentially leading them to perform setup without proper power-off procedures.

[0050] The aforementioned shortcomings may lead to the neglect of safety regulations (organizational management measures) and the need for maintenance while the main switch is on.

[0051] The background of this invention relates to the following risk assessment regarding security risks: • Staff must work at the DC box (DC voltage port / test equipment) to prepare the object under test (DUT) there. At this time, staff must also be located on the facility's busbars. • Due to the high-risk situation and the accompanying high risk, it leads to a high-risk scenario (risk level is the 4th of the 5 possible levels). • Busbars are live parts that can carry up to 1000V DC voltage. • There is a risk of electric shock, which could result in serious injury or death. Therefore, a high level of technical and functional security is required.

[0052] The risk assessment is based on the following assumptions: • Serious (irreversible) injury or death is expected. • Exposure is occasional to infrequent, and / or short-term.

[0053] This invention is based on the following concept:

[0054] Due to the potentially high risk, and considering the foreseeable misoperation or avoidance response when power is cut off via the main switch, there is a need for a feasible solution to safely cut off power directly at the connection point (DC voltage port / test equipment / DC box).

[0055] For space and cost reasons, no additional disconnecting switch should be installed at the connection point (strictly speaking, see above). Instead, safe power disconnection should be achieved from the connection point to the rest of the test site via a remote control unit. Furthermore, existing switching and actuating elements in the test site that are readily available in practice should be used for power disconnection.

[0056] Two mechanisms are provided for this in the test environment known in practice: 1. Output contactor on the DC side (at the DC voltage output terminal) 2. Isolation transformers for primary / secondary isolation (in resonant converters)

[0057] Regarding point 1: According to the standard, contactors are not permitted as stand-alone protection against electric shock. However, since they contribute to the diversity and redundancy of isolation regardless of this regulation, DC-side output contactors are incorporated into the protection scheme.

[0058] Regarding point 2: In practice, transformers with safety isolation features are generally recognized as protection against electric shock, provided that these transformers generate non-hazardous voltage levels on the secondary side. This particularly includes all types of consumer power adapters / chargers used with electronic devices. Unlike these devices, the output voltage generated by the isolation transformers in the test station could be life-threatening if touched. Establishing safe isolation for these transformers means disconnecting them, i.e., stopping the flow of energy through them. The energy flow through the transformer is only realized when an AC voltage is applied to the input terminals of the transformer. This AC voltage is generated in the test field by an inverter (part of a resonant converter), which is driven by a PWM signal from an internal control unit (PWM generator). The principle of safe isolation of the transformer is based on the following: the operating voltage of the control unit (PWM generator) that generates and transmits the PWM signal is removed via a safe path. Without PWM, even if a component fails, the inverter will not generate AC voltage, and therefore energy transfer via the transformer can no longer be achieved.

[0059] By combining the output contactor with isolation via a transformer, measures for "power-off" and "prevention of reconnection" that are equivalent to or better than those established in practice are achieved in the test field.

[0060] This is ensured, in particular, through continuous monitoring of the two redundant disconnect paths (monitoring unit) and internal diagnostics of the operational functionality (diagnostic unit). This diagnostic function specifically includes monitoring for the discharge of hazardous intermediate circuit voltages within the facility at specific times. Violation of this condition will result in the facility entering a persistent fault state, which can only be reset by service technicians, due to the presence of a hardware defect. Attached Figure Description

[0061] Further features, effects, and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention and the accompanying drawings. These are illustrated schematically:

[0062] Figure 1 A schematic block diagram of the test site is shown, which includes two test stations and one energy source. Detailed Implementation

[0063] Figure 1 The test field 2 for this bipolar test object 4 is shown. In the example, there are actually two test objects 4 connected to the test field 2. Electrical tests are performed on the test objects 4 using the test field 2. For this purpose, a high-power electrical system 6 of up to 1 MW is fed into or derived from the test object 4, depending on the test requirements. In the example, the high-power electrical system 6 is represented by a double arrow.

[0064] In the example, each test object 4 is shown as both a test device 8 (here called a DC box) and a real test object 10 (DUT 10). The two DUTs 10 are, in this case, the power battery and drive motor of an electric vehicle. The DC box is used to connect the real test object in the form of the DUT 10 to the test field 2.

[0065] Test site 2 includes an energy source 12, which in turn includes a generator 14 and a converter 16. The generator 14 provides an AC voltage UW during operation, which in this example is a three-phase AC voltage of 400V. The converter 16 is connected to the generator 14 and is used to commutate the AC voltage UW into a bipolar (positive and negative) DC voltage UG, which is applied at the bipolar first DC voltage interface 18 of the converter 16, or rather, the energy source 12.

[0066] Test site 2 also includes two test stations 20. Each test station 20 is used for exactly one of the test subjects 4 in this same bipolar connection.

[0067] Each test station 20 includes a resonant converter 22 and a buck regulator 24. The resonant converter 22, or test station 20, has a bipolar second DC voltage interface 26. The buck regulator 24, or test station 20, has a bipolar DC voltage port 28 for its respective test object 4 on the side opposite to the resonant converter 22. The resonant converter 22 converts the DC voltage UG on the second DC voltage interface 26 into an AC voltage UW, which is then converted back into a DC voltage UG at the DC voltage port 28 by the buck regulator 24. As described above, the DC voltage port 28 also refers to this output terminal if necessary, when the output terminal of the test equipment 8 connected to the DUT 10 needs to be protected as an "interface" so that work (e.g., servicing the DUT 10) can be safely performed there.

[0068] Test site 2 also includes a bipolar DC voltage bus 30. A first DC voltage interface 18 and a second DC voltage interface 26 are both connected to this DC voltage bus 30 (its two conductive rails, not shown) to electrically connect these components to each other. The DC voltage bus 30 distributes DC voltage UG between the power source 12 and the test station 20.

[0069] Therefore, the DC voltage bus 30 implements a DC voltage intermediate loop in the test field 2, and transmits an 825V DC voltage UG during operation.

[0070] Each resonant converter 22 includes a transformer 32, which has a primary side 34 and a secondary side 36. The primary side 34 faces the second DC voltage interface 26, and the secondary side 36 faces the DC voltage port 28.

[0071] Each test station 20 also includes a PWM generator 38. This generator can be supplied with the operating voltage UB when the operating switch 40, as symbolically understood, is closed. The corresponding PWM generator 38 is configured to always and only supply the PWM signal PS generated or being generated by the DC voltage UG at the second DC voltage interface 26 to the primary side 34 of the transformer 32 when it is supplied with the operating voltage UB.

[0072] Each test station 20 also includes a switch 44, which is located between the secondary side 36 of the transformer 32 and the DC voltage port 28. Figure 1 The location of switch 44 should also be understood symbolically; this switch is not necessarily located within the step-down regulator 24. Switch 44 here is not an isolating switch, but a contactor.

[0073] Switch 44 is used to interrupt or establish the electrical connection between DC voltage port 28 and transformer 32, or the secondary side 36 of the transformer.

[0074] Test site 2 also includes a safety control unit 46, which is also associated with both test stations 20. The safety control unit 46 is configured to place one or more of the test stations 20 into a protection state SZ. In this protection state, the safety control unit switches the PWM generator 38 in the relevant test station 20 to be disconnected from the operating voltage UB by disconnecting switch 40, and maintains this disconnected state. Furthermore, in protection state SZ, the safety control unit also disconnects switch 44 in the relevant test station 20 and maintains its disconnected state.

[0075] Therefore, this operation occurs selectively on the selected test station 20, while the other test stations 20 in test field 2 can continue to operate in principle.

[0076] The safety control unit 46 also includes a protection device 42. This protection device prevents the reconnection of the operating voltage UB (closing switch 40) and the closing of switch 44 regarding the relevant test station 20. Therefore, the protection device ensures that voltage is not accidentally applied again at the DC voltage port 28 in the relevant test station 20 and endangers personnel safety there.

[0077] Test site 2 also includes operating elements 48, one for each test station 20. Operating elements 48 are configured to place the safety control unit 46 into a protected state SZ for the relevant test station 20, or to activate that protected state for the relevant test station 20. Operating elements 48 are respectively arranged at the relevant DC voltage port 28, i.e., within the local environment or effective range of the operator located at the DC voltage port 28 and wishing to perform work there. Therefore, the operator can operate the operating element 48 located nearby or there, thereby switching the DC voltage port 28 to a de-voltage state, allowing for safe work at that DC voltage port.

[0078] The operating element 48 is designed as a remote control unit because the safety control unit 46 is arranged away from the operating element 48.

[0079] Figure 1 A room layout system 52 is also shown, which includes a first room 54, a second room 56, and a third room 58. The energy source and safety control unit 46 are arranged together in the first room 54, the upper test station 20 and its operating elements 48 are arranged in the second room 56, and the lower test station 20 and its operating elements 48 are arranged in the third room 56.

[0080] Each DC voltage port 28 is also located in the second room 56 / third room 58 and is connected to the rest of the test station 20 in the first room 54 (here, the step-down regulator 24) via its respective power supply line 50. Therefore, the DC voltage ports 28 are located away from the rest of the test station 20 and are connected to the rest of the test station 20 only via the power supply line 50.

[0081] therefore, Figure 1 Room layout system 52 is also shown. This room layout system includes a first room 54 in which not only the energy source 12 is arranged but also the test station 20 (the rest of the room). The first room 54 is air-conditioned. Room layout system 52 also includes a second room 56 and a third room 58. Therefore, the first room 54 is the power supply room for the test site 2. The second and third rooms 56 and 58 are test rooms. The object under test 4 is located in these test rooms. The test equipment 8 here is a fixed-mount switch cabinet in the second room 56 and the third room 58, which is connected to the actual test station (not shown in detail in the figure). At the test station, the actual DUT 10 is connected to the test equipment 8 for testing.

[0082] Therefore, the operating element 48 is arranged in the respective second chamber 56 and third chamber 58, and is thus undoubtedly associated with the corresponding DC voltage port 28 in the second chamber 56 or third chamber 58 in order to reliably identify, accurately target, and quickly switch it to a voltage-free state. The power supply line 50 then extends from the first chamber 54 to the second chamber 56 and the third chamber 58, respectively.

[0083] The test object 4 is not connected to the DC voltage port 28 via a plug connector, but rather via a conductive rail (not shown). This connection requires direct operation on the uninsulated conductive rail. Specifically, the conductive rail needs to be manipulated at a location between the test equipment 8 and the DUT 10.

[0084] Test site 2 also includes a monitoring unit 60 with an output unit 62. The output unit 62 is also located at the relevant DC voltage port 28 in the second room 56 and the third room 58. The monitoring unit 60 is configured to monitor, under protection state SZ, whether the PWM generator 38 is actually not being supplied with the operating voltage UB for the relevant test station 20, and whether the electrical connection between the transformer 32 and the DC voltage port 28 is actually interrupted by the switch 44. If not, the monitoring unit 60 is configured to output an alarm at the relevant output unit 62.

[0085] The monitoring unit 60 is also equipped with a self-diagnostic unit 64. This self-diagnostic unit is configured to perform self-diagnostics on the functionality of the monitoring unit 60. If functionality cannot be guaranteed, the self-diagnostic unit is configured to place the test site 2 into a persistent fault state FZ. This fault state can only be reset by someone outside the test site 2 (here, by service technicians) after functionality is restored.

[0086] List of reference numerals

[0087] 2 Test Field

[0088] 4. Test Subjects

[0089] 6 High power

[0090] 8. Testing Equipment

[0091] 10 DUT

[0092] 12 Energy Sources

[0093] 14 Generator

[0094] 16 Converters

[0095] 18 First DC Voltage Interface

[0096] 20 test stations

[0097] 22 Resonant Converter

[0098] 24. Step-down regulator

[0099] 26 Second DC voltage interface

[0100] 28 DC voltage ports

[0101] 30 DC voltage bus

[0102] 32 Transformers

[0103] 34 Primary side

[0104] 36 secondary sides

[0105] 38 PWM generator

[0106] 40 Operation Switch

[0107] 42. Protective equipment (reconnect)

[0108] 44 Switches

[0109] 46. ​​Safety Control Department

[0110] 48 Operating elements

[0111] 50 power supply lines

[0112] 52-room layout system

[0113] 54 First Room

[0114] 56 Second Room

[0115] 58 Third Room

[0116] 60 monitoring units

[0117] 62 Output Units

[0118] 64 Self-diagnostic Unit

[0119] UW AC voltage

[0120] UG DC voltage

[0121] UB operating voltage

[0122] PS PWM signal

[0123] SZ Protection Status

[0124] FZ Fault Status

Claims

1. A test field (2) for a test object (4), the test field being used to perform electrical testing on the test object (4) by means of electrical high power at a DC voltage (UG) to be fed to and / or derived from the test object, - The test field has a DC voltage bus (30) for guiding DC voltage (UG). - The test field has at least one power source (12) having a first DC voltage interface (18) for the DC voltage bus (30). - The test field has multiple test stations (20), each test station is used for one of the test objects (4), the test station includes a second DC voltage interface (26) for the DC voltage bus (30) and a DC voltage port (28) for the respective test object (4). - in, All test stations (20) are connected to each other via the DC voltage bus (30) based on their second DC voltage interface (26) and all energy sources (12) based on their first DC voltage interface (18). - Each of the test stations (20) includes a resonant converter (22) which includes a transformer (32) having a primary side (34) facing the second DC voltage interface (26) and a secondary side (36) facing the DC voltage port (28). - Each of the test stations (20) includes a PWM generator (38) configured to supply a PWM signal (PS) generated by the DC voltage (UG) at the second DC voltage interface (26) to the primary side (34) when an operating voltage (UB) is supplied. - Each of the test stations (20) includes a switch (44) arranged between the secondary side (36) and the DC voltage port (28) to interrupt the electrical connection between the secondary side (36) and the DC voltage port (28). - The test field has a safety control unit (46) configured to: disconnect the PWM generator (38) from the operating voltage (UB) and keep it disconnected in the protection state (SZ), and disconnect the switch (44) and keep it disconnected.

2. The test field (2) according to claim 1. Its features are, The switch (44) is not an isolating switch or a load isolating switch.

3. The test field (2) according to claim 2. Its features are, The switch (44) is a contactor.

4. The test field (2) according to any one of the preceding claims. Its features are, The safety control unit (46) has a protection device (42) to prevent the operating voltage (UB) from being reconnected at the PWM generator (38) and to prevent the switch (44) from being reconnected.

5. The test field (2) according to any one of the preceding claims. Its features are, The test field (2) includes at least one operating element (48) configured to activate the protection state (SZ) with respect to at least one of the test stations (20) in the safety control unit (46), wherein the operating element (48) is arranged at a DC voltage port (28).

6. The test field (2) according to claim 5. Its features are, The operating element (48) is a remote control unit for a remotely deployed safety control unit (46).

7. The test field (2) according to any one of the preceding claims. Its features are, The DC voltage port (28) is connected to the rest of the test station (20) via a power supply line (50) and is arranged away from the rest of the test station (20).

8. The test field (2) according to any one of the preceding claims. Its features are, The tested object (4) is not or cannot be connected to the DC voltage port (28) via a plug connector.

9. The test field (2) according to any one of the preceding claims. Its features are, Each test station (20) in the test field (2) includes a monitoring unit (60) with an output unit (62) located at a DC voltage port (28). The monitoring unit (60) is configured to monitor, in protection state (SZ), whether the PWM generator (38) is actually not supplied with the operating voltage (UB) and whether the electrical connection via the switch (44) is actually disconnected, and if not, to provide an alarm at the output unit (62).

10. The test field (2) according to claim 9. Its features are, Each test station (20) of the test field (2) includes a diagnostic unit (64) which is associated with the monitoring unit (60) and is configured to perform self-diagnosis of the functionality of the monitoring unit (60) and, if the functionality is not confirmed, place the test field (2) in a persistent fault state (FZ).

11. Room layout system (52) The room layout system has at least two rooms (54, 56, 58) and a test field (2) according to any one of the preceding claims, the test field (2) being arranged in at least two of the rooms (54, 56, 58) of the room layout system (52), such that a DC voltage port (28) is arranged in a first room of the rooms (54, 56, 58), and at least a portion of the remaining portion of the test field (2) is arranged in a second room of the rooms (54, 56, 58).

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