Contactor device and method for operating contactor device
By arranging the temperature sensor and control unit outside the contactor, calculating the internal temperature of the contactor, the problem of difficult to measure the internal temperature of the contactor is solved, and high-accurate temperature monitoring and safe operation of the contactor are achieved.
Patent Information
- Application Number
- CN202380062136.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-10-11
- Filing Date
- 2023-10-10
- Publication Date
- 2025-04-04
AI Technical Summary
In electric vehicles or other electronic devices carrying high currents, the movable contact elements inside the contactor may be damaged due to thermal stress, and it is difficult to directly measure the internal temperature of the contact bridge due to structural limitations and electromagnetic interference.
By arranging a first temperature sensor outside the housing of the contactor, directly contacting the first terminal or its busbar to measure the external temperature, and a second temperature sensor on the housing or on the carrier, the ambient temperature is measured. The internal temperature of the contact bridge is calculated using the control unit, based on external and ambient temperature readings, and provides a warning signal when the internal temperature exceeds a threshold.
The internal temperature of the contactor is calculated with high accuracy when approaching or reaching the thermal load limit, avoiding unnecessary reduction in ratings, and ensuring safe operation of the contactor as close to its design limit as possible.
Smart Images
Figure CN119768984A_ABST
Abstract
Description
[0001] A contactor device and a method for operating a contactor device are described in detail.
[0002] For example, contactors are used in electric vehicles or other electronic devices for carrying high currents (such as currents exceeding 100 amperes). For example, the contactor includes a fixed contact element and a movable contact element arranged in a housing. The contact element is electrically connected to the terminals of the contactor. Specifically, the movable contact element can disconnect or close the electrical connection between the two terminals by disconnecting or closing the contact with one or more fixed contact elements. For example, a movable contact element (such as a contact bridge) can use a fixed contact element to disconnect or close a single contact, or it can use two fixed contact elements connected to corresponding terminals to disconnect or close two contacts at the same time. The movable contact element can be moved by applying a force (such as a mechanical force or an electromagnetic force). For example, the contactor includes a driver coil, and if a current flows through the driver coil, the driver coil switches the movable contact element by magnetic force.
[0003] The movable contact element inside the contactor may carry a large current and may therefore exhibit large thermal stress. For example, heat is generated due to the contact resistance between the movable contact element and the fixed contact element. Excess heat may be trapped inside the contactor housing and may damage components of the contactor during operation. In order to avoid damage to the contactor during operation, if the temperature inside the contactor exceeds the maximum operating temperature, it will be beneficial to reduce the rating of the contactor. For example, after reducing the rating of the contactor, the current flowing through the contact bridge is reduced, so that the heat generated inside the contactor is reduced. However, due to structural limitations and / or due to, for example, electromagnetic interference, it may not be feasible to arrange the temperature sensor inside the contactor next to the contact bridge. In addition, arranging the temperature sensor inside the contactor may increase the production cost of the contactor.
[0004] It is an object of at least one of certain embodiments to provide a contactor device that operates without overheating and a method for operating the contactor device.
[0005] This object is achieved by the subject matter of the independent claims. Further embodiments and further advantageous developments are specified in the dependent claims.
[0006] According to an embodiment, the contactor device comprises a contactor having a contact bridge for switching an electrical connection between a first terminal and a second terminal during operation. For example, the contact bridge can be moved during operation and allows the electrical connection between the first terminal and the second terminal to be opened or closed. The first terminal and the second terminal are configured for external electrical contact of the contactor. For example, a busbar for transmitting high current to and from the contactor is connected to the first terminal and / or the second terminal.
[0007] According to another embodiment, the contactor device comprises a first temperature sensor, which is in direct contact with the first terminal or with a busbar electrically connected to the first terminal. For example, the first temperature sensor is arranged outside the housing of the contactor. Preferably, the first temperature sensor is configured to measure the temperature of the first terminal or the busbar connected to the first terminal during operation. Here and hereinafter, the temperature of the first terminal or the busbar connected to the first terminal measured by the first temperature sensor is denoted as "external temperature".
[0008] For example, the first temperature sensor is a temperature-dependent resistor or a thermistor. The thermistor may have a positive temperature coefficient (PTC) or a negative temperature coefficient (NTC). Advantageously, the first temperature sensor may be arranged as close as possible to the contact bridge.
[0009] According to another embodiment, the contactor device comprises a second temperature sensor, which is configured to measure the ambient temperature outside the contactor during operation. For example, the second temperature sensor is arranged on the housing of the contactor or on the carrier where the contactor is mounted. Specifically, the second temperature sensor is not in direct contact with the first terminal, the second terminal or the busbar connected to the first terminal or the second terminal. For example, the second temperature sensor is a temperature-dependent resistor or a thermistor.
[0010] According to another embodiment, the contactor device comprises a control unit configured to calculate the internal temperature of the contact bridge inside the contactor. In other words, the control unit predicts the internal temperature of the contact bridge. For example, the control unit comprises or consists of an integrated circuit or an application specific integrated circuit (ASIC). Specifically, the control unit obtains readings of external sensors (such as a first temperature sensor and a second temperature sensor) as input data. Preferably, the control unit processes the input data to generate an output. For example, the control unit comprises an analog-to-digital converter and a processing unit to perform mathematical operations on the input data.
[0011] In particular, the control unit is configured for calculating the internal temperature of the contact bridge as a function of time during operation. In other words, the internal temperature is calculated at a series of consecutive time steps during operation based on time-dependent input data.
[0012] Preferably, the control unit is configured to calculate the internal temperature with high accuracy. In other words, at any time during operation, the difference between the predicted internal temperature and the actual temperature of the contact bridge inside the contactor is small. For example, the predicted internal temperature differs from the actual temperature of the contact bridge by at most 20°C, or at most 10°C, or at most 5°C. Advantageously, by calculating the internal temperature with higher accuracy, the temperature safety margin required to safely operate the contactor device can be smaller, thereby improving the performance of the contactor device. Specifically, during safe operation, the internal temperature of the contactor will not exceed the maximum allowable operating temperature, thereby avoiding damage to the contactor device.
[0013] According to another embodiment of the contactor device, the internal temperature depends on the temperature readings of the first temperature sensor and the second temperature sensor. In other words, the control unit obtains the external temperature reading and the ambient temperature reading as input data in order to calculate the internal temperature of the contact bridge inside the contactor. In order to improve the accuracy of the calculated internal temperature, the first temperature sensor can be arranged as close as possible to the contact bridge.
[0014] According to another embodiment of the contactor device, the control unit is configured to provide a warning signal if the internal temperature exceeds a threshold value. For example, the warning signal is an output generated by the control unit based on a calculation performed on the input data. For example, after the warning signal is generated, a rating reduction of the contactor is performed. The rating reduction may involve reducing the current flowing through the contact bridge, for example in order to protect the contactor from thermal damage.
[0015] For example, the threshold value is a temperature value corresponding to the thermal load limit of the contactor. In other words, the threshold value corresponds to the maximum operating temperature of the contactor. For example, during continuous operation, the maximum operating temperature may correspond to 230°C, or for a maximum operating time of 5 minutes, the maximum operating temperature may correspond to 250°C. Specifically, if the internal temperature exceeds the maximum operating temperature, the contactor may be damaged. The threshold value may include a safety margin and may be lower than the maximum operating temperature of the contactor. For example, the threshold value may be 10°C lower, preferably 5°C lower than the maximum operating temperature.
[0016] For a contactor comprising more than one contact bridge, the control unit may be configured to calculate the internal temperature of each contact bridge individually. In this case, the control unit may provide a warning signal, for example, based on the maximum predicted temperature in the predicted temperatures.
[0017] According to a preferred embodiment, the contactor device comprises:
[0018] a contactor having a contact bridge for switching an electrical connection between the first terminal and the second terminal during operation,
[0019] a first temperature sensor in direct contact with the first terminal or with a busbar electrically connected to the first terminal,
[0020] - a second temperature sensor configured to measure the ambient temperature external to the contactor during operation, and
[0021] - a control unit configured to calculate the internal temperature of a contact bridge inside the contactor, wherein
[0022] - the internal temperature depends on the temperature readings of the first temperature sensor and the second temperature sensor, and
[0023] - The control unit is configured to provide a warning signal if the internal temperature exceeds a threshold value.
[0024] The contactor device disclosed herein is based on the following concept: calculating with high accuracy and thereby predicting the internal temperature of the contact bridge inside the contactor allows the contactor to operate close to or at its thermal load limit. In other words, by calculating the internal temperature, the contactor can be safely operated close to its maximum operating temperature without the need for a large safety margin based on the worst-case assumption. Specifically, in the absence of an accurate estimate of the internal temperature, the restrictive worst-case assumption will result in a substantial loss of performance of the contactor under normal operating conditions. For example, in the absence of an accurate estimate of the internal temperature, a reduction in the rating of the contactor may be triggered at a relatively low internal temperature compared to the maximum operating temperature, which is unnecessary. In contrast, the contactor device described in detail herein can be safely operated at all times and under all operating conditions without compromising its performance or with minimal performance loss. Here, performance refers to operating the contactor as close to its design limit as possible, and specifically operating as close to its maximum allowable operating temperature as possible.
[0025] For example, the actual temperature of the contact bridge inside the contactor depends on the pole resistance of the contact bridge, which may change during the operation of the contactor or over the life of the contactor and may be difficult to measure. In addition, due to structural limitations inside the contactor and / or due to electromagnetic interference caused by, for example, switching high currents during operation, it may be difficult to directly measure the actual temperature of the contact bridge. In addition, the difference between the external temperature and the internal temperature may be highly dependent on time and may increase as the current flowing through the contact bridge increases and / or due to changes in the pole resistance. Therefore, estimating the internal temperature based solely on the measurement results of the external temperature may not be sufficient to accurately determine the internal temperature. In contrast, the contactor device disclosed herein allows the internal temperature to be determined with high accuracy based on the measurement results of both the external temperature and the ambient temperature. Advantageously, it is not necessary to measure the temperature directly at the contact bridge to accurately determine the internal temperature.
[0026] According to another embodiment of the contactor device, the contact bridge is configured to carry a maximum current of at least 350 amperes. For example, the contact bridge is configured to carry a maximum current of at least 500 amperes or at least 1000 amperes. Specifically, the contact bridge is configured to carry the maximum current continuously without time limit. Due to carrying such high currents, the contact bridge may be subject to thermal stress. Therefore, determining the internal temperature of the contact bridge is beneficial to protect the contactor from thermal damage during operation.
[0027] According to another embodiment of the contactor device, the contactor includes an active or passive cooling member. For example, the housing of the contactor includes a passive cooling element or a radiator. Alternatively or in addition, the radiator can be arranged to be in thermal contact with a busbar next to the terminal so as to effectively dissipate the heat generated inside the contactor. For example, the contactor device may also include an active cooling system, such as a liquid cooling system, an electrically driven fan, a heat pump, or an evaporative cooler, so as to actively cool the contactor during operation. For example, the liquid cooling system includes a cooling plate thermally connected to the busbar, wherein a liquid coolant (such as water) flows through channels inside the cooling plate. Specifically, active or passive cooling may increase the electrical load limit of the contactor.
[0028] According to another embodiment, the contactor device further comprises an air pressure sensor for measuring the ambient air pressure outside the contactor, and the control unit is configured to calculate the internal temperature also depending on the reading of the air pressure sensor. In other words, the ambient air pressure is part of the input data of the control unit. For example, in addition to other input data (such as temperature readings from the first temperature sensor and the second temperature sensor), the control unit also calculates the internal temperature based on the ambient air pressure reading.
[0029] According to another embodiment, the contactor device further comprises a current sensor for measuring the current flowing through the contact bridge during operation, and the control unit is configured to calculate the internal temperature also depending on the reading of the current sensor. In other words, the current flowing through the contact bridge during operation is part of the input data of the control unit. For example, in addition to other input data (such as temperature readings from the first temperature sensor and the second temperature sensor and a reading from the ambient air pressure sensor), the control unit also calculates the internal temperature based on the current reading.
[0030] According to another embodiment of the contactor device, the internal temperature depends on the readings of the first temperature sensor at two consecutive time steps. For example, the calculated internal temperature depends on a current external temperature reading and a past external temperature reading. For example, the control unit comprises a memory for storing the external temperature reading at a time step before the time at which the internal temperature was calculated.
[0031] According to another embodiment of the contactor device, the time interval between two consecutive time steps is less than or equal to the characteristic heating time of the first terminal and / or the busbar. Here and hereinafter, the characteristic heating time of the first terminal is a characteristic of the contactor device, which specifies the time span over which the temperature of the first terminal reaches 63% of the equilibrium temperature when a constant current flows through the first terminal causing ohmic heating. Similarly, the characteristic heating time of the busbar is a characteristic of the contactor device, which specifies the time span over which the temperature of the busbar reaches 63% of the equilibrium temperature when a constant current flows through the busbar causing ohmic heating. Advantageously, by using a time interval between consecutive time steps that is less than the characteristic heating time of the first terminal and / or the busbar, the accuracy of the calculated internal temperature can be improved.
[0032] Further, a method for operating a contactor device is described in detail herein. Specifically, the method is configured to operate a contactor device as described in detail herein. All features of the contactor device are also disclosed for the method for operating the contactor device, and vice versa.
[0033] According to an embodiment, a method for operating a contactor arrangement comprises the step of measuring an external temperature of the contactor at a first terminal of the contactor or at a busbar electrically connected to the first terminal of the contactor.
[0034] According to another embodiment, a method for operating a contactor device comprises the following steps: measuring the ambient temperature outside the contactor. For example, the ambient temperature is measured at a distance from a current-carrying part of the contactor device, such as a busbar or a terminal of the contactor.
[0035] According to another embodiment, a method for operating a contactor device comprises the following steps: calculating an internal temperature of a contact bridge inside the contactor, wherein the internal temperature depends on the external temperature and the ambient temperature, and the contact bridge is configured to switch an electrical connection between a first terminal and a second terminal of the contactor. For example, the internal temperature is calculated by a control unit that obtains readings of the external temperature and the ambient temperature as input data.
[0036] According to another embodiment, the method for operating a contactor device comprises the following steps: if the internal temperature exceeds a threshold value, a warning signal is provided. For example, the threshold value corresponds to the maximum operating temperature of the contact bridge. For example, the warning signal is generated as an output of the control unit and can also be used to reduce the rating of the contactor in order to avoid damage caused by overheating.
[0037] In addition, the control unit can provide the rate of increase of the internal temperature as a function of time as an additional output. In other words, the control unit can provide information about the speed at which the internal temperature exceeds a threshold value. For example, the contactor can be derated according to the rate of increase of the internal temperature. For example, the derated when the current flowing through the contact bridge is reduced is proportional to the rate of increase of the internal temperature. The control unit can be used to reduce the rating of the contactor and / or control the contactor so that the contactor operates when it reaches its thermal load limit or approaches its thermal load limit, thereby avoiding performance loss.
[0038] According to a further embodiment of the method for operating a contactor arrangement, the internal temperature is calculated via the following relation:
[0039]
[0040] in, Indicates that at time t 2 The internal temperature at Represents an earlier time t 1 The internal temperature at i is the characteristic heating time of the contact bridge, and is determined from the measured external temperature and from the measured ambient temperature. Here and hereinafter, the characteristic heating time of the contact bridge is a characteristic of the contactor device which specifies the time span over which the temperature of the contact bridge reaches 63% of the equilibrium temperature when a constant current flows through the contact bridge causing ohmic heating.
[0041] Characteristic heating time τ i is a characteristic of the contactor device and can be used as a parameter for calculating the internal temperature. For example, the characteristic heating time can be determined during an initial calibration step and can be stored in the control unit. Alternatively or in addition, the characteristic heating time can be determined statistically from measurements of a large number of similar contactor devices.
[0042] Specifically, the calculated internal temperature Depends on the internal temperature calculated in the previous time step As an initial condition for calculating the internal temperature, the initial internal temperature can be set to the measured ambient temperature if the contactor has enough time to cool to the ambient temperature.
[0043] Alternatively, the initial condition for the calculated internal temperature may be determined according to the following relationship:
[0044]
[0045] This takes into account the local cooling of the contact bridge after the previous operation of the contactor. represents the initial condition of the internal temperature, is the ambient temperature at the initial time, is the internal temperature calculated when the contactor device was previously closed, and Δt is the cooling time span between the time when the contactor was closed and the initial time.
[0046] According to a further embodiment of the method for operating a contactor arrangement, It is calculated by the following relationship:
[0047]
[0048] in, and are respectively at time t 1 and t 2 The measured external temperature of the space, is at time t 2 is the measured ambient temperature, P is the calibration parameter, and τ e is the characteristic heating time of the first terminal and / or busbar. For example, the heating time of the busbar or the first terminal is greater than the heating time of the contact bridge, i.e. τ e >τ i Calibration parameter P and characteristic heating time τ e is a parameter used to calculate the internal temperature and can be stored in the control unit.
[0049] Specifically, the calibration parameter P is based on the assumption that the external temperature and the internal temperature are proportional to each other in thermal equilibrium. In other words, it is assumed that the following relationship holds:
[0050]
[0051] in, and are the steady-state values of the internal and external temperatures in thermal equilibrium, respectively, and represents the ambient temperature. For example, the steady-state value of the internal temperature is greater than the steady-state value of the external temperature, and therefore P>1.
[0052] According to a further embodiment of the method for operating a contactor arrangement, the characteristic heating time τ of the contact bridge i and / or the characteristic heating time τ of the first terminal or busbar e Depends on the ambient air pressure. For example, if τ is adjusted according to the ambient air pressure measured by the ambient air pressure sensor i and / or τ e , the accuracy of the calculated internal temperature can be improved.
[0053] According to another embodiment of the method for operating a contactor device, the calibration parameter P depends on the current flowing through the contact bridge during operation. Specifically, if P is adjusted according to the current flowing through the contact bridge measured by the current sensor, the accuracy of the calculated internal temperature can be improved.
[0054] Further advantageous embodiments and further embodiments of the contactor device and of the method for operating a contactor device become apparent from the following exemplary embodiments which are described in conjunction with the drawings.
[0055] Figure 1 and Figure 2 Schematic contactor arrangements according to various exemplary embodiments are shown.
[0056] Figure 3 The temperature evolution of a contactor arrangement according to an exemplary embodiment is shown.
[0057] Figure 4 A diagram corresponding to a method for operating a contactor arrangement according to an exemplary embodiment is shown.
[0058] Figures 5 to 15 Different temperature evolutions of contactor arrangements according to exemplary embodiments are shown.
[0059] Fig.16 and Fig.17 The calculated internal temperature T of the contactor device according to different initial conditions of the exemplary embodiment is shown. i The influence of time evolution.
[0060] Fig.18 1 shows the calculated internal temperature T of the contactor arrangement according to different arrangements of the first temperature sensor according to an exemplary embodiment. i The influence of time evolution.
[0061] Fig.19 A schematic top view of a portion of a contactor arrangement according to an exemplary embodiment is shown, wherein a first temperature sensor has different installation positions.
[0062] Fig. 20 and Fig.21 FIG. 4 shows the error of the second temperature sensor versus the calculated internal temperature T of the contactor device according to an exemplary embodiment. i The influence of time evolution.
[0063] Fig. 22 and Fig.23 FIG. 4 shows the error of the first temperature sensor versus the calculated internal temperature T of the contactor device according to an exemplary embodiment. i The influence of time evolution.
[0064] Fig.24 and Fig.25 FIG. 4 shows the effect of the time delay between the readings of the first temperature sensor and the second temperature sensor on the internal temperature T of the contactor device according to an exemplary embodiment. i Calculation.
[0065] Fig.26 and Fig. 27 The error of the characteristic heating time versus the calculated internal temperature T of the contactor device according to an exemplary embodiment is shown. i The influence of time evolution.
[0066] In the drawings, identical, similar or elements having the same effect are indicated by the same reference numerals. The drawings and the proportions of the elements shown in the drawings should not be considered to be drawn to true scale. On the contrary, individual elements may be shown exaggeratedly for better presentation and / or better understanding.
[0067] according to Figure 1 The contactor device 1 of the exemplary embodiment in the embodiment includes a contactor 2, a first temperature sensor 51, a second temperature sensor 52, and a control unit 7. The contactor 2 includes a housing 21 and a movable contact bridge 3 located inside the housing 21. The contact bridge 3 is configured to switch the electrical connection between the first terminal 41 and the second terminal 42. The busbar 6 for transmitting high current to and from the contactor 2 is electrically connected to the first terminal 41 and the second terminal 42. For example, the busbar 6 is also connected to a battery and a motor (not shown), and the contactor 2 is configured to switch the electrical connection between the battery and the motor during operation.
[0068] The first temperature sensor 51 is in direct contact with the busbar 6 connected to the first terminal 41 and is configured to measure the external temperature T e The second temperature sensor 52 is configured to measure the ambient temperature T outside the contactor housing 21. amb .
[0069] The control unit 7 is configured to calculate the internal temperature T of the contact bridge 3 based on the readings of the first temperature sensor 51 and the second temperature sensor 52. i Specifically, the control unit 7 calculates the internal temperature T as a function of time with high accuracy and dynamically at a series of discrete time steps during operation. i In addition, if the calculated internal temperature T i If the threshold value is exceeded, the control unit 7 is configured to generate a warning signal 71 in order to protect the contactor 2 from thermal damage during operation. For example, the threshold value is equal to the maximum operating temperature of the contactor 2.
[0070] About Figure 1Compared with the disclosed contactor device 1, according to Figure 2 The contactor device 1 of the exemplary embodiment in further includes an ambient air pressure sensor 8, a current sensor 9, and an element 10 for contactor cooling. The ambient air pressure sensor 8 is configured to measure the ambient air pressure H outside the contactor housing 21 during operation, and the current sensor 9 is configured to measure the current I flowing through the contact bridge 3 during operation. The element 10 for cooling is a heat sink thermally coupled to the busbar 6 of the contactor device 1. An element 10 for cooling may also be arranged at each busbar 6 to effectively dissipate the heat generated inside the contactor 2. Each of the ambient air pressure sensor 8, the current sensor 9, and the element 10 for cooling may be separately included as an optional element. Figure 1 in the implementation method.
[0071] The control unit 7 obtains the readings of the first temperature sensor 51 and the second temperature sensor 52, the ambient air pressure sensor 8 and the current sensor 9 to calculate the internal temperature T i .and Figure 1 The additional readings of the ambient air pressure sensor 8 and the current sensor 9 allow the internal temperature T to be calculated with greater accuracy compared to the exemplary embodiment in FIG. i .
[0072] Figure 3 Shows about Figure 1 The internal temperature T of the contactor device 1 described i and the measured external temperature T e As a function of time t. Specifically, Figure 3 shows that when a constant current of 350A is applied at an ambient temperature of 20°C amb Internal temperature T when the current flows through the contact bridge 3 i and the external temperature T e The time evolution of the internal temperature T i Than the external temperature T e Therefore, the characteristic heating time τ of the contact bridge 3 is i Less than the characteristic heating time τ of busbar 6 e In addition, the internal temperature T i Higher than the external temperature T e .
[0073] Figure 4 The diagram in FIG. 1 depicts a method for operating a contactor device according to an exemplary embodiment. Specifically, the control unit 7 acquires the external temperature T measured by the first temperature sensor 51. e and the ambient temperature T measured by the second temperature sensor 52 amb In addition, the control unit 7 takes the characteristic heating time τ of the contact bridge as input data. i, characteristic heating time τ of the first terminal or busbar e The stored value of and the calibration parameter P are retrieved together with the input data to calculate the internal temperature T of the contact bridge 3. i If the calculated internal temperature T i If the threshold value is exceeded, the control unit 7 provides a warning signal 71 as output data. In order to increase the predicted internal temperature T i To increase the accuracy of the measurement, the control unit 7 may use an optional ambient pressure H reading from the ambient pressure sensor 8 and an optional current I reading from the current sensor 9 as further input data.
[0074] Figures 5 to 15 shows the calculated internal temperature T i , the actual internal temperature T of the contact bridge 3 i,测量 and the measured external temperature T e In response to the flow according to the combination Figure 1 The time evolution of different time-dependent currents I of the contact bridge 3 of the contactor device 1 of the described exemplary embodiment. For different examples, the maximum current I of the corresponding time-dependent current curve max Take a value between 100A and 1500A. Specifically, Figures 5 to 16 shows that regardless of the detailed form of the current I curve, the calculated internal temperature T i The actual internal temperature T of the contact bridge 3 is accurately predicted. i,测量 .
[0075] Fig.16 Shows the combination Figure 1 The calculated internal temperature T of the contactor device 1 described i The time evolution of the contactor device is Figure 7 The current I curve shown is operated. Different internal temperatures T are calculated for initial condition deviations of the internal temperature of ±10°C and ±50°C. i After a period of about 300 seconds, the calculated internal temperature is roughly independent of the initial conditions.
[0076] Fig.17 Shown with Fig.16 Same data, but given the calculated internal temperature T for the reference initial condition i ,参考 From the calculated internal temperatures T corresponding to different initial conditions i Minus.
[0077] Fig.18 Shown with Figure 7 Similar data, but the calculated internal temperature T iCorresponding to a contactor device 1 in which the first temperature sensor 51 is arranged at a greater distance from the first terminal 41. Specifically, Fig.18 It is shown that if the first temperature sensor 51 is arranged at a greater distance from the contact bridge 3, Figure 7 Compared to the calculated internal temperature T i The actual internal temperature T of the contact bridge 3 i,测量 The difference between them is large, and therefore the calculated internal temperature T i The accuracy is lower.
[0078] Fig.19 The first temperature sensor 51 is shown in combination with Figure 1 Different mounting positions 511, 512 in the contactor device 1 are described. The first mounting position 511 is located at the first terminal 41, while the second mounting position is located on the busbar 6 at a certain distance from the first terminal 41. Specifically, Figure 7 The calculated internal temperature T is shown i Corresponding to the first temperature sensor 51 installed at the first installation position 511, Fig.18 The calculated internal temperature T is shown i Corresponding to the first temperature sensor 51 installed at the second installation position 512 .
[0079] Fig. 20 Shows the combination Figure 1 The calculated internal temperature T of the contactor device 1 described i The time evolution of the contactor device is Figure 7 The current I curve shown is operated. For the ambient temperature T of the second temperature sensor 52 amb Different exemplary errors of ±5°C and ±10°C of the reading, calculated for different internal temperatures T i curve.
[0080] Fig.21 Shown with Fig. 20 Same data, but at ambient temperature T amb The calculated internal temperature T when there is no error in the reading i,参考 From the different ambient temperature T amb The reading corresponds to the calculated internal temperature T i Specifically, the calculated internal temperature T i The error is less than the ambient temperature T amb Error in readings.
[0081] Fig. 22 Shows the combination Figure 1 The calculated internal temperature T of the contactor device 1 described iThe time evolution of the contactor device is Figure 7 The current I curve shown is operated. For the external temperature T of the first temperature sensor 51 e Different errors of ±5°C and ±10°C of the reading, calculated for different internal temperatures T i curve.
[0082] Fig.23 Shown with Fig. 22 Same data, but at external temperature T e The calculated internal temperature T when there is no error in the reading i,参考 From the different external temperature T e The reading corresponds to the calculated internal temperature T i Specifically, the calculated internal temperature T i The error is greater than the external temperature T e Error in readings.
[0083] Fig.24 Shows the combination Figure 1 The calculated internal temperature T of the contactor device 1 described i The time evolution of the contactor device is Figure 7 Specifically, T i,延迟 Corresponding to the calculated internal temperature T i The calculated internal temperature when the readings of the first temperature sensor 51 and the second temperature sensor 52 are delayed by 10 seconds.
[0084] Fig.25 Shown with Fig.24 Same data, but actual internal temperature T of contact bridge 3 i,测量 From the calculated internal temperature T i and T i,延迟 A 10-second time delay in the temperature measurement will cause the predicted internal temperature T i The offset is 10 seconds, resulting in a slight increase in the forecast under-estimation when the temperature increases and a slight increase in the forecast over-estimation when the temperature decreases. However, if the time delay is known, the calibration parameters can be adjusted to optimize the prediction.
[0085] Fig.26 Shows the combination Figure 1 The calculated internal temperature T of the contactor device 1 described i The time evolution of the contactor device is Figure 7 The current I curve is shown in Figure 1. The characteristic heating time τ of the contact bridge 3 and the busbar 6 i and τ e Different internal temperature curves T are calculated for the case of -10% error and no error i,误差and T i .
[0086] Fig. 27 Shown with Fig.26 Same data, but actual internal temperature T of contact bridge 3 i,测量 From the calculated internal temperature T i and T i,误差 Subtract. Characteristic heating time τ i and τ e Reduce by 10% the calculated internal temperature T i The impact on accuracy is negligible.
[0087] The present invention is not limited to the exemplary embodiments due to the description based on the exemplary embodiments. On the contrary, the present invention covers any new features and any combination of features, specifically including any combination of features in the patent claims and any combination of features in the exemplary embodiments, even if the feature or the combination itself is not explicitly described in the patent claims or the exemplary embodiments.
[0088] Reference numerals
[0089] 1 Contactor device
[0090] 2 Contactor
[0091] 21 Shell
[0092] 3 Contact bridge
[0093] 41 First terminal
[0094] 42 Second terminal
[0095] 51 First temperature sensor
[0096] 511 First installation position
[0097] 512 Second installation position
[0098] 52 Second temperature sensor
[0099] 6 Busbar
[0100] 7 Control unit
[0101] 71 Warning Signs
[0102] 8 Air pressure sensor
[0103] 9 Current sensor
[0104] 10 Cooling element
[0105] I Current
[0106] Imax Maximum current
[0107] H Ambient air pressure
[0108] T i Calculated internal temperature
[0109] T i,测量 Actual internal temperature
[0110] T i,延迟 Calculated internal temperature with time delay
[0111] T i,误差 Calculated internal temperature with error
[0112] T e External temperature
[0113] T amb Ambient temperature
[0114] t time
[0115] τ i Heating time of contact bridge
[0116] τ e Heating time of busbar / contact terminal
[0117] P calibration parameters
Claims
1. A contactor device (1), comprising: a contactor (2) having a contact bridge (3) for switching an electrical connection between a first terminal (41) and a second terminal (42) during operation, a first temperature sensor (51) in direct contact with the first terminal (41) or with a busbar (6) electrically connected to the first terminal (41), - a second temperature sensor (52) configured to measure the ambient temperature (T amb ),as well as - a control unit (7) configured to calculate the internal temperature (T i ),in, - the internal temperature (T i ) depends on the temperature readings of the first temperature sensor (51) and the second temperature sensor (52), and - the control unit (7) is configured to: if the internal temperature (T i ) exceeds a threshold, a warning signal (71) is provided.
2. The contactor device (1) according to the preceding claim, in, The contact bridge (3) is configured to carry a maximum current (I) of at least 350 amperes.
3. The contactor device (1) according to any one of the preceding claims, in, The contactor (2) comprises an active or passive cooling element (10).
4. The contactor device (1) according to any one of the preceding claims, wherein: - the contactor device (1) further comprises: an air pressure sensor (8) for measuring the ambient air pressure (H) outside the contactor (2), and - the control unit (7) is configured to calculate the internal temperature (T i ).
5. The contactor device (1) according to any one of the preceding claims, wherein: - the contactor device (1) further comprises: a current sensor (9) for measuring the current (I) flowing through the contact bridge (3) during operation, and - the control unit (7) is configured to calculate the internal temperature (T i ).
6. The contactor device (1) according to any one of the preceding claims, in, The internal temperature (T i ) depends on the reading of the first temperature sensor (51) at two consecutive time steps.
7. Contactor device (1) according to the preceding claim, in, The time interval between two consecutive time steps is less than or equal to the characteristic heating time (τ) of the first terminal (41) and / or the busbar (6). e ).
8. A method for operating a contactor device (1), comprising the following steps: - measuring the external temperature (T ) of the contactor (2) at the first terminal (41) of the contactor (2) or at the busbar (6) electrically connected to the first terminal (41) of the contactor (2) e ), -Measure the ambient temperature (T) outside the contactor (2) amb ), - Calculate the internal temperature (T i ), wherein the internal temperature (T i ) depends on the external temperature (T e ) and the ambient temperature (T amb ), and the contact bridge (3) is configured to switch the electrical connection between the first terminal (41) and the second terminal (42) of the contactor (2), - If the internal temperature (T i ) exceeds a threshold, a warning signal (71) is provided.
9. The method according to the preceding claim, in, The internal temperature (T i ) is through the relation To calculate, among which, represents the internal temperature at time t2, represents the internal temperature at an earlier time t1, τ i is the characteristic heating time of the contact bridge, and is based on the measured external temperature (T e ) and according to the measured ambient temperature (T amb ) to determine.
10. The method according to the preceding claim, in, Through the relation Calculated, where and are the external temperatures measured at time t1 and t2, respectively, is the ambient temperature measured at time t2, P is the calibration parameter, and τ e is the characteristic heating time of the first terminal (41) and / or the busbar (6).
11. The method according to claim 9 or 10, in, The characteristic heating time τ of the contact bridge (3) i and / or the characteristic heating time τ of the first terminal (41) or the busbar (6) e Depends on the ambient air pressure (H).
12. The method according to claim 10, in, The calibration parameter P depends on the current (I) flowing through the contact bridge (3) during operation.