System and method for detecting an electrical short circuit

Abstract

To provide methods and systems of detecting short circuits in an electrical system, such as a dynamic braking grid of a vehicle.SOLUTION: The methods and systems measure a characteristic of an electrical current that is conducted through one or more resistive elements of an electrical system 104. The electrical current is supplied to the electrical system from a power source 102 as an applied voltage. A resistance change signal representative of a change in one or more electrical resistances of the one or more resistive elements is determined. The resistance change signal is based at least in part on a difference between the characteristic of the electrical current that is measured and a low pass filtered value of one or more of the characteristic of the electrical current that is measured or the applied voltage supplied by the power source. A short circuit event is identified based at least in part on the resistance change signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the inventive subject matter described herein relate to the detection of electrical short circuits in an electronic system, such as a power resistor.

Background Art

[0002] Known electronic systems include those that conduct current through a resistor to dissipate the current. For example, some vehicles include a grid having conductive ribbons that receive power generated by a motor during regenerative braking or dynamic braking. This power is generated by the motor and acts to slow or stop the movement of the vehicle. The power is conducted to the grid to be dissipated as heat from the vehicle's regenerative braking system.

[0003] The grid can be formed from one or more series of resistors. These resistors can be implemented in conductive plates that are positioned relatively close to each other. Over time, due to damage to the grid, standard wear, or other reasons, the relative positions of the resistors with respect to each other can begin to change. If the resistors come into contact with each other (e.g., due to vibration or other movement), an internal electrical short circuit can occur between the resistors. This short circuit can damage the grid, damage the regenerative braking system, and otherwise have an adverse effect on the operation of the vehicle.

Summary of the Invention

[0004] In one embodiment, a method (e.g., for detecting a short circuit in an electrical system) includes measuring characteristics of a current conducted through one or more resistive elements of the electrical system. The current is supplied to the electrical system from a power source as an applied voltage. The method also includes determining a resistance change signal representative of a change in one or more electrical resistances of the one or more resistive elements. The resistance change signal can be at least partially based on a difference between the measured characteristics of the current and one or more low-pass filtered values of the measured characteristics of the current or the applied voltage supplied by the power source. The method can also include identifying a short circuit event based at least partially on the resistance change signal.

[0005] In another embodiment, a system (e.g., a detection system) includes a sensing device and a processing assembly. The sensing device is configured to measure characteristics of a current conducted through one or more resistive elements of an electrical system. The current may be supplied to the electrical system from a power source as an applied voltage. The processing assembly may be configured to determine a resistance change signal representative of a change in an electrical resistance of one or more of the one or more resistive elements. The resistance change signal may be at least partially based on a difference between the measured characteristics of the current and one or more low-pass filtered values of the measured characteristics of the current or the applied voltage supplied by the power source. The processing assembly may be configured to identify a short circuit event based at least partially on the resistance change signal.

Brief Description of the Drawings

[0006] Reference is now made briefly to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0007] One or more embodiments of the inventive subject matter described herein detect an electrical short circuit in an electronic system. In one aspect, the systems and methods described herein may be used to detect an electrical short circuit in a dynamic braking grid (DBG) of a vehicle such as a railway vehicle or other off-highway vehicle (OHV). However, not all embodiments are limited to DBGs or railway vehicles. One or more embodiments may be used to detect a short circuit in other systems, including non-vehicle systems and vehicle systems other than railway vehicles or OHVs.

[0008] During operation of the DBG, an electrical short circuit may occur in the conductive plate of the DBG, and the current of the DBG may bypass at least a portion of the electrical resistance formed by the plate. The plate may short circuit, for example, when shaken by an air flow created by a blower (e.g., a fan) that dissipates heat generated by the current into the air around the plate. However, the plate may also short circuit due to the thermal cycle of the DBG, which may cause distortion and / or migration of the metal elements. These short circuits may form local hot spots between two or more plates, which may ultimately lead to sparks, melting, arcing, and failure of the DBG.

[0009] To prevent failures of the DBG, the systems and methods described herein may provide early detection of electrical short circuits. By detecting short circuits early, preventive inspections and maintenance can be performed, thereby avoiding more serious damage and / or downtime of the DBG or other electrical systems.

[0010] FIG. 1 illustrates a power system (100) in one embodiment. Although the power system (100) is shown as a locomotive, alternatively it may be a different type of system or a different type of vehicle that is not a vehicle. The system (100) includes a power source (102), such as a traction motor that generates power, for example, during regenerative braking operation. Alternatively, the power source (102) may represent an alternator, a generator, a battery, or other power source. The power source (102) generates an electric current, and the electric current is conducted to an electrical system (104). The electrical system (104) includes one or more resistive elements, such as power resistors. These resistive elements convert the electric current from the power source (102) into heat. The heat can be dissipated from the power system (100) by, for example, a blower (e.g., a fan). In the illustrated embodiment, the power source (102) may include a traction motor that generates an electric current during regenerative braking of the electric system (100). The electrical system (104) may include a DBG that converts electrical power into heat and dissipates it.

[0011] FIG. 2 illustrates a schematic diagram of an electrical system (104) and an electrical short circuit detection system (200) (referred to as the "detection system" in FIG. 2) in one embodiment. The system (104) includes several electrical resistive elements (202) connected in series with each other in a conducting state. In the illustrated embodiment, the resistive elements (202) are conducting plates, such as two-dimensional conductive bodies having an outer shape in which two orthogonal directions are longer than a third direction orthogonal to them. Alternatively, the resistive elements (202) may be other types of resistors. During operation of the system (104), the power from the power source (102) is conducted through the resistive elements (202). The resistive elements (202) reduce the flow of the electric current through the electrical system (104) and convert the power into heat. As one example, during regenerative braking of a vehicle, the power generated by the traction motor of the vehicle can be conducted to the resistive elements (202) (e.g., the DBG) and dissipated as heat.

[0012] The resistive elements (202) can be arranged at relatively close intervals. During operation, the resistive elements (202) may change their relative positions with respect to each other due to the air flow generated by the blower, and / or may bend or deform due to the heat generated by the power conducted to the resistive elements (202). Due to this position change and / or deformation, the resistive elements (202) may come into contact with each other and cause an electrical short circuit. The short circuit may damage the power system (100) and / or limit the operation of the power system (100).

[0013] The detection system (200) is conductively connected to the electrical system (104) at one or more locations and monitors the electrical characteristics of the current conducted through the electrical system (104). The detection system (200) monitors the change in the electrical resistance of the electrical system (104) over time and detects an electrical short circuit based on these changes. For example, while the resistive elements (202) are not in contact with each other, the voltage and / or current conducted through the resistive elements (202) may be proportional to the voltage generated by the power source (102). Since the voltage and / or current generated by the power source (102) and conducted to the electrical system (104) is the voltage or current applied to the resistive elements (202), it can be referred to as the applied voltage (V dc ) or applied current. The voltage and / or current conducted through the resistive elements (202) (referred to herein as the conduction voltage or conduction current) may be proportional to the applied voltage and / or applied current by one or more proportionality constants. For example, the product of the conduction voltage and the proportionality constant is equal to the input voltage, and / or the product of the conduction current and the same or another proportionality constant is equal to the input voltage. The proportionality constants are the same or substantially the same over time.

[0014] However, when two or more of the resistive elements (202) come into contact with each other at least momentarily and cause an electrical short circuit, the proportionality constant may change abruptly. Therefore, an abrupt change in the ratio of the conduction voltage and / or conduction current may mean an electrical short circuit. The detection system (200) monitors the changes in the conduction voltage or conduction current, and / or the changes in the ratio of these voltages and / or currents, in order to quickly identify the short circuit before the electrical short circuit damages the operation of the electrical system (104) and / or the power system (100).

[0015] Figure 3 is a circuit diagram of one embodiment for an electrical system (104) and a detection system (200). Various resistor element groups (202) are connected in parallel with each other, and the resistor elements (202) within those resistor element groups are connected in series with each other. For example, the resistor elements (202) labeled "1", "2", and "3" are connected in series with each other in the first group, the resistor elements (202) labeled "4", "5", and "6" are connected in series with each other in the second group, the resistor elements (202) labeled "7", "8", and "9" are connected in series with each other in the third group, and the resistor elements (202) labeled "10", "11", and "12" are connected in series with each other in the fourth group, and the first group, the second group, the third group, and the fourth group can be parallel to each other. A switch (304) is arranged on the opposite side of the resistor elements (202) of each group, and it is possible to control which resistor element (202) receives the applied current from the power supply (102).

[0016] The detection system (200) includes a sensing device (300) that is conductively connected to the resistor element (202). The sensing device (300) represents one or more device p that measures the characteristics of the current supplied to the electrical system (104) by the power supply (102). For example, the sensing device (300) can measure the conductive voltage and / or the conductive current. For example, the sensing device (300) can include one or more voltmeters and / or ammeters (302) ("VAM" in Figure 3), a high voltage filter (306) ("High V" in Figure 3), and / or a low voltage filter (308) ("Low V" in Figure 3). The voltmeter / ammeter (302) and / or the filters (306, 308) can measure the voltage between the resistor elements (202) at the positions shown in Figure 3 and / or at other positions, and / or the voltage drop between two or more resistor elements (202). Alternatively, the sensing device (300) can include another type of sensor that measures the voltage and / or current conducted between and / or through the resistor elements (202).

[0017] The detection system (200) may also include a processing assembly (310) operably connected to the sensing device (300). For example, the processing assembly (310) and the sensing device (300) can be connected by one or more wired and / or wireless connections. The processing assembly (310) includes one or more processors (312) ( "Processing" in FIG. 3, for example, a microprocessor, a controller, or other electrically logic-based device), and / or is connected to them, including hardware circuits and / or electrical circuits. This circuit can include an input / output module (314) ( "I / O" in FIG. 3) and an input / output board (316) ( "CIO" in FIG. 3). The input / output module (314) can represent hardware circuits and / or electrical circuits that include one or more processors that generate signals to be output for presentation to an operator (for example, signals transmitted to a display device to warn the operator of a detected short circuit), and / or are connected to them. The input / output board (316) can represent hardware circuits and / or electrical circuits that include one or more processors that transmit signals to a display device or other output device, and / or are connected to them. Optionally, the input / output board (316) can receive signal inputs from one or more other devices, such as a signal representing an applied voltage generated by the power supply (102) and conducted to the electrical system (104).

[0018] FIG. 4 is a flowchart relating to one embodiment of a method (400) for detecting a short circuit event. The method (400) can be implemented by a detection system (300) in one embodiment. At (402), the conduction voltage and the conduction current are measured by the sensing device (300). At (404), the applied voltage and / or the applied current supplied to the electrical system (104) by the power supply (102) is determined. For example, the sensing device (300) is connected to the electrical system (104) at one or more locations and measures the applied voltage from the power supply (102).

[0019] (406) calculates the difference between the measured voltage and / or measured current (e.g., conduction voltage and / or conduction current) and the ratio after filtering of the measured voltage and / or measured current to the applied voltage and / or applied current. These differences can be called resistance change signals.

[0020] The processing assembly (310) can calculate the ratio of the conduction voltage and / or conduction current and determine the proportionality constant of the electrical system (104). For example, the processing assembly (310) divides the conduction voltage measured between the second and third resistance elements (202) (elements "2" and "3" in FIG. 3) by the conduction voltage measured between the fifth and sixth resistance elements (202) (elements "5" and "6" in FIG. 3), between the eighth and ninth resistance elements (202) (elements "8" and "9" in FIG. 3), between the tenth and eleventh resistance elements (202) (elements "10" and "11" in FIG. 3), or between another pair of resistance elements (202). Additional ratios can be measured to calculate further proportionality constants for the electrical system (104).

[0021] During normal operation (e.g., when there is no short circuit), the proportionality constant is the same or substantially the same (does not change within a specified threshold, e.g., 1%, 3%, 5% or another value). However, over time, the resistance provided by the resistance elements (202) can change slowly with time. As a result, the proportionality constant can change slowly with time. The proportionality constant can be called a resistance change signal. In a normal state (e.g., when there is no short circuit), the change in the proportionality constant may simply include noise and is not an actual change in the proportionality constant. A short circuit can occur during a contact event between two or more resistance elements (202). In such a contact event, the resistance change signal rises above the noise and can indicate a short circuit.

[0022] In one embodiment, the processing assembly (310) can calculate the resistance change signal from the applied voltage and the conduction voltage. Alternatively, the resistance change signal can be calculated from the applied current and the conduction current. Although the description herein focuses on calculating the resistance change signal from voltage, not all embodiments are limited to the use of voltage.

[0023] One example of a resistance change signal that can be calculated by the processing assembly (310) is a ratio deviation signal. In one embodiment, the processing assembly (310) calculates the ratio deviation signal as follows: TIFF0007706300000001.tif15150 (Equation 1) At this time, RatioDeviation(t) represents the ratio deviation signal, V grid (t) represents the voltage of the electrical system (104) or the grid (e.g., the conduction voltage), V base (t) represents the applied voltage or the base voltage, or the applied voltage divided by a constant such as 6 or other numbers, and TIFF0007706300000002.tif15150 is TIFF0007706300000003.tif15150 represents the low-pass filtering of TIFF0007706300000004.tif15150 By performing low-pass filtering on the value of TIFF0007706300000005.tif15150 due to the change of within a short time less than the specified time, such as within 100 milliseconds, within 50 milliseconds, within 0.1 second or other times, the increase or decrease of TIFF0007706300000006.tif15150 that starts and ends can be ignored, while the increase or decrease of TIFF0007706300000007.tif15150 that continues longer than the specified time is TIFF0007706300000008.tif15150 used as the value of

[0024] TIFF0007706300000009.tif15150 The value of TIFF0007706300000010.tif15150 can be used as the baseline or expected value for the ratio deviation signal. Within a time period when the proportionality constant does not change significantly, TIFF0007706300000011.tif15150 the value of TIFF0007706300000012.tif15150 and the value of TIFF0007706300000013.tif15150 are close numerical values, and as a result, the ratio deviation signal is smaller or zero. However, within a time period when the proportionality constant changes significantly,

[0025] the value of TIFF0007706300000014.tif22150 (Equation 2) At this time, VoltageDeviation(t) represents the voltage deviation signal.

[0026] Another example of the resistance change signal that can be calculated by the processing assembly (310) is the following deviation squared signal: TIFF0007706300000015.tif11150 TIFF0007706300000016.tif8150 (Equation 3) At this time, TIFF0007706300000017.tif6150 represents the deviation squared signal, TIFF0007706300000018.tif8150 is TIFF0007706300000019.tif8150 represents the low-pass filtering of TIFF0007706300000020.tif8150 is TIFF0007706300000021.tif8150 represents the low-pass filtering of

[0027] (408) determines whether the difference between the measured voltage and / or measured current (e.g., the conduction voltage and / or conduction current) and the ratio of the filtered measured voltage and / or measured current to the applied voltage and / or applied current suggests a short-circuit event. For example, the processing assembly (310) can examine the resistance change signal to identify a short-circuit event.

[0028] Regarding the ratio deviation signal (RatioDeviation(t)) described above, a short - circuit event can be identified corresponding to the absolute value of the ratio deviation signal exceeding a threshold value (K). The threshold value is selectable, thereby changing the sensitivity of the detection system (200). For example, when the threshold value (K) is relatively small, the sensitivity to short - circuits is high, but the possibility of misidentifying short - circuit events is also high. When the threshold value (K) is relatively large, the sensitivity to short - circuits is low, but the possibility of misidentifying short - circuit events is low.

[0029] Regarding the voltage deviation signal (VoltageDeviation(t)) described above, a short - circuit event can be identified by the processing assembly (312) that monitors the value of the voltage deviation signal. For example, a short - circuit event can be identified corresponding to the absolute value of the voltage deviation signal exceeding the product of the threshold value (K) and V base (t).

[0030] Regarding the squared - deviation signal (VoltageSquaredDeviation(t)) described above, a short - circuit event can be identified by the processing assembly (312) that monitors the value of the squared - deviation signal. For example, a short - circuit event can be identified corresponding to the absolute value of the squared - deviation signal exceeding the product of the threshold value (K), V base (t) and <V base (t)>.

[0031] When a short - circuit event is detected, the flow of the method (400) can proceed to (410). Otherwise, the flow of the method (400) can return to (402) to additionally monitor the electrical system (104). At (410), the cumulative value of the short - circuit event is changed. For example, in contrast to determining that a short - circuit event has occurred each time the resistance - change signal indicates a short - circuit, the processing assembly (310) can track a cumulative value whose value changes based on the number, duration, and / or energy of the short - circuit events.

[0032] As an example, the processing assembly (310) can calculate the cumulative value of the short - circuit event as the total number of short - circuit events. An increase in the value of such a cumulative value can indicate an increase in the severity of the short - circuit event.

[0033] As another example, the processing assembly (310) can calculate a cumulative value as the total duration of the short - circuit event. For example, the total duration that the resistance change signal exceeds one or more of the above - described thresholds can be calculated as the cumulative value. If a short - circuit event lasts for 1 second, followed by a 0.5 - second short - circuit event and then another 2 - second short - circuit event, the total duration of the short - circuit event can be 3.5 seconds. An increase in the total duration can mean an increase in the damage to the resistive element (202) compared to a shorter total duration. The total duration can be reset to 0, for example, after the power system (100) has moved from the starting position to the target position.

[0034] As another example, the processing assembly (310) can calculate a cumulative value as the energy of the short - circuit event. For example, the processing assembly (310) can calculate the cumulative value as the time integral of the deviation - squared signal during short - circuit event detection. This cumulative value can indicate, and / or be proportional to, the thermal energy or heat quantity directed towards the contact point between the resistive elements (202) where the short - circuit event is occurring.

[0035] At (412), a determination is made as to whether the cumulative value indicates that the electrical system (104) is damaged (and thus, is causing a short - circuit event). In one embodiment, the processing assembly (310) can compare one or more of the cumulative values with a specified associated threshold. If the cumulative value exceeds the threshold, the processing assembly (310) can determine that the electrical system (104) appears to be damaged. As a result, the flow can continue to (414). Otherwise, the flow of the method (400) can return to (402).

[0036] (414) A warning signal is generated. This warning signal is generated by the processing assembly (310) and can be presented to the operator of the power system (100). The warning signal can indicate to the operator that the electrical system (104) is in an initial stage of damage such as detachment. In one aspect, the cumulative value can be compared to several different thresholds (e.g., various detachment stages) representing different levels of damage. The thresholds can be determined by testing the electrical system (104) to a destructive state while measuring the above quantity, and during that time, setting the thresholds based on engineering judgment. The warning signal can be used to control the operation of the power system (100). For example, the warning signal can disable the power system (100) to reduce the power output, or otherwise reduce the operation of the power system (100) to prevent further damage to the electrical system (104).

[0037] The method (400) can be repeated one or more times during the operation of the power system (100). For example, the flow of the method (400) can return to (402) for additional monitoring of the electrical system (104).

[0038] In one embodiment, the method (for example, for short - circuit detection in an electrical system) includes the step of measuring the characteristics of a current conducted through one or more resistive elements of the electrical system. The current is supplied to the electrical system from a power source as an applied voltage. The method further includes the step of determining a resistance change signal representing a change in the electrical resistance of one or more of the one or more resistive elements. The resistance change signal can be at least partially based on the difference between the measured characteristics of the current and one or more low - pass filtered values of the measured characteristics of the current or the applied voltage supplied by the power source. The method can further include the step of identifying a short - circuit event at least partially based on the resistance change signal.

[0039] In one aspect, the applied voltage can be generated by the traction motor of the vehicle during regenerative braking of the vehicle, one or more resistive elements can include one or more resistors of the regenerative braking grid, and / or the conduction voltage can include a voltage drop across one or more resistors.

[0040] In one aspect, the resistance change signal can represent a change in the electrical resistance of one or more resistive elements caused by an increase in heat within the one or more resistive elements due to a short - circuit event.

[0041] In one aspect, the characteristics of the measured current may include a voltage drop across at least one of the resistive elements.

[0042] In one aspect, the resistance change signal may represent the difference between the ratio of the voltage drop across at least one of the resistive elements to the applied voltage and the value after low-pass filtering of the ratio of the voltage drop across at least one of the resistive elements to the applied voltage.

[0043] In one aspect, a short circuit event may be identified corresponding to the absolute value of the resistance change signal exceeding a specified non-zero threshold.

[0044] In one aspect, the resistance change signal may represent the difference between the voltage drop across at least one of the resistive elements and the product of the applied voltage and the value after low-pass filtering of the ratio of the voltage drop across at least one of the resistive elements to the applied voltage.

[0045] In one aspect, a short circuit event may be identified corresponding to the absolute value of the resistance change signal exceeding the product of the applied voltage and a specified non-zero threshold.

[0046] In one aspect, the resistance change signal may represent the difference between a first product of the voltage drop across at least one of the resistive elements and the value after low-pass filtering of the applied voltage and a second product of the applied voltage and the value after low-pass filtering of the voltage drop across at least one of the resistive elements.

[0047] In one aspect, a short circuit event may be identified corresponding to the absolute value of the resistance change signal exceeding the product of the applied voltage, the voltage drop across at least one resistive element, and a specified non-zero threshold.

[0048] In one aspect, the method may further include monitoring the number of times a short circuit event is identified, and generating a warning signal indicative of damage to the electrical system corresponding to the number of times the short circuit event is identified exceeding a specified non-zero threshold.

[0049] In one aspect, the method may further include monitoring the combined duration of the short circuit events, and generating a warning signal indicative of damage to the electrical system corresponding to the total duration exceeding a specified non-zero threshold.

[0050] In one aspect, the method may further include monitoring the time integral of the resistance change signal, and generating a warning signal representative of damage to the electrical system corresponding to the time integral exceeding a specified non-zero threshold.

[0051] In one aspect, the method may further include generating a warning signal at least partially based on the identification of the short circuit event. The warning signal can indicate damage to the electrical system to an operator of a power system including the electrical system.

[0052] In another embodiment, a system (e.g., a detection system) includes a sensing device and a processing assembly. The sensing device is configured to measure characteristics of a current conducted through one or more resistive elements of an electrical system. The current may be supplied to the electrical system from a power source as an applied voltage. The processing assembly may be configured to determine a resistance change signal representative of a change in one or more electrical resistances of the one or more resistive elements. The resistance change signal may be at least partially based on a difference between the measured characteristics of the current and one or more low-pass filtered values of the measured characteristics of the current or the applied voltage supplied by the power source. The processing assembly may further be configured to identify a short circuit event at least partially based on the resistance change signal.

[0053] In one aspect, the applied voltage can be generated by a traction motor of a vehicle during regenerative braking of the vehicle, the one or more resistive elements can include one or more resistors of a regenerative braking grid, and the conduction voltage can include a voltage drop across the one or more resistors.

[0054] In one aspect, the resistance change signal can represent a change in one or more electrical resistances caused by an increase in heat in the one or more resistive elements due to a short circuit event.

[0055] In one aspect, the measured characteristics of the current can include a voltage drop across at least one of the resistive elements.

[0056] In one aspect, the resistance change signal can represent a difference between a ratio of a voltage drop across at least one of the resistive elements to the applied voltage and a low-pass filtered value of the ratio of the voltage drop across at least one of the resistive elements to the applied voltage.

[0057] In one aspect, the processing assembly can be configured to identify a short circuit event corresponding to an absolute value of the resistance change signal that exceeds a specified non-zero threshold.

[0058] In one aspect, the resistance change signal can represent a difference between a voltage drop across at least one of the resistive elements and a product of the applied voltage and a low-pass filtered value of a ratio of the voltage drop across at least one of the resistive elements to the applied voltage.

[0059] In one aspect, the processing assembly can be configured to identify a short circuit event corresponding to an absolute value of the resistance change signal that exceeds a product of the applied voltage and a specified non-zero threshold.

[0060] In one aspect, the resistance change signal can represent the difference between a first product of a value after low-pass filtering of at least one resistance element and an applied voltage, and a second product of a value after low-pass filtering of the applied voltage and a voltage drop across the at least one resistance element.

[0061] In one aspect, the processing assembly can be configured to identify a short-circuit event in response to an absolute value of the resistance change signal that exceeds a product of an applied voltage, a voltage drop across at least one resistance element, and a specified non-zero threshold.

[0062] In one aspect, the processing assembly can be configured to monitor the number of times a short-circuit event is identified and generate a warning signal indicative of damage to the electrical system corresponding to the number of times a short-circuit event is identified that exceeds a specified non-zero threshold.

[0063] In one aspect, the processing assembly can be configured to monitor the total duration of a short-circuit event and generate a warning signal indicative of damage to the electrical system corresponding to a total duration that exceeds a specified non-zero threshold.

[0064] In one aspect, the processing assembly can be configured to monitor the time integral of the resistance change signal and generate a warning signal indicative of damage to the electrical system corresponding to a time integral that exceeds a specified non-zero threshold.

[0065] In one aspect, the processing assembly can be configured to generate a warning signal based at least in part on the identification of a short-circuit event. The warning signal can indicate damage to the electrical system to an operator of a power system including the electrical system.

[0066] It should be understood that the above description is illustrative and not restrictive. For example, the embodiments (and / or aspects) described above may be used in combination with each other. In addition, without departing from the scope of the present invention, many modifications can be made to adapt the teachings of the inventive subject matter to a particular situation or material. The dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, but they are by no means restrictive and are typical embodiments. Upon review of the above description, many other embodiments will be apparent to those of ordinary skill in the art. Accordingly, the scope of the inventive subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which the claims are entitled. In the appended claims, the terms "including" and "in which" are used as plain English synonyms for "comprising" and "wherein", respectively. Also, in the following claims, the terms "first", "second", and "third", etc. are used merely as labels and are not intended to impose numerical requirements on their objects. Further, the limitations in the following claims are not written in the form of "means-plus-function", and such claim limitations are not intended to be construed under 35 U.S.C. § 112(f) unless the claim explicitly uses the phrase "means for" followed by a description of the function and then is further accompanied by additional structure or is further accompanied by additional structure thereafter.

[0067] In this written description, examples are used to disclose several embodiments of the inventive subject matter and to enable those of ordinary skill in the art to practice the embodiments of the inventive subject matter, including the making and use of any device or system and the performance of any methods included therein. The patentable scope of the inventive subject matter is defined by the claims, and other examples that may be contemplated by those of ordinary skill in the art can be included. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims or if they include equivalents of structural elements that do not differ substantially from the literal language of the claims.

[0068] The foregoing description of specific embodiments of the subject matter of the present invention will be better understood when read in conjunction with the accompanying drawings. To the extent that the figures show schematic views of functional blocks of various embodiments, the functional blocks are not necessarily meant to indicate a separation between hardware circuits. Thus, for example, one or more functional blocks (such as a processor or memory) can be implemented in a single piece of hardware (such as a general-purpose message processor, microcontroller, random access memory, hard disk, etc.). Similarly, a program can be an independent program, incorporated as a subroutine into an operating system, or a function of an installed software package. The various embodiments are not limited to the arrangements and means shown in the drawings.

[0069] As used herein, an element or step recited in the singular and preceded by the word "a" or "an" should be understood to exclude a plurality of the said elements or steps unless explicitly stated otherwise. Further, reference to "one embodiment" of the subject matter of the present invention is not intended to be construed as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, an embodiment "comprising", "including", or "having" one element or a plurality of elements having a particular characteristic can include additional elements not having that characteristic unless explicitly stated otherwise.

Claims

1. (1)A step of measuring the characteristics of a current flowing through one or more resistive elements of the electrical system, which is generated by supplying an applied voltage from a power source to the electrical system; (2)A step of determining a resistance change signal of the one or more resistive elements based on a filter process using the characteristics of the current measured in the step (1); (3)A method including a step of identifying a short - circuit event based on the resistance change signal determined in the step (2), wherein the characteristics of the measured current are determined by a voltage drop across the one or more resistive elements caused by the current flowing through the one or more resistive elements; furthermore, the filter process is a process of excluding the characteristics and / or the applied voltage that occur and end in a short time less than a specified time; in addition, the resistance change signal is determined by the following formula based on the difference between the voltage drop across the one or more resistive elements and the product of the applied voltage and the value after filter processing of the ratio of the voltage drop across the one or more resistive elements to the applied voltage, In the above formula, VoltageDeviation(t) is the voltage deviation signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is, the value after the filter processing of, characterized by the method.

2. The method according to claim 1, wherein the short - circuit event is identified in response to the resistance change signal exceeding the product of the applied voltage and a specified non - zero threshold value.

3. (1)A step of measuring the characteristics of a current flowing through one or more resistive elements of the electrical system, which is generated by supplying an applied voltage from a power source to the electrical system; (2)A step of determining a resistance change signal of the one or more resistive elements based on a filter process using the characteristics of the current measured in the step (1); (3)A method including a step of identifying a short - circuit event based on the resistance change signal determined in the step (2), wherein the characteristics of the measured current are determined by a voltage drop across the one or more resistive elements caused by the current flowing through the one or more resistive elements, and furthermore, the filter process is a process of excluding the characteristics and / or the applied voltage that occur and end in a short time less than a specified time; in addition, the resistance change signal is determined by the following formula based on the difference between the first product of the voltage drop across the one or more resistive elements and the value after the first filter processing of the applied voltage and the second product of the applied voltage and the value after the second filter processing of the voltage drop across the one or more resistive elements, In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is, which is the value after the first filtering process of is which is the value after the second filtering process of A method characterized by the above. **Claim 4** The method according to claim 3, wherein the electrical system is a power generation braking grid. **Claim 5** (1) Measuring the characteristics of a current conducted through one or more resistive elements of the electrical system, which is generated by applying a voltage from a power source to the electrical system; (2) Determining a resistance change signal of the one or more resistive elements based on a filtering process using the characteristics of the current measured in step (1); (3) Identifying a short - circuit event based on the resistance change signal determined in step (2), a method comprising: The filtering process is a process of excluding the characteristics and / or the applied voltage that occur and end in a short time less than a specified time; The characteristics of the measured current are determined by the voltage drop across the one or more resistive elements caused by the current flowing through the one or more resistive elements; The method Monitoring one or more of the number of times the short - circuit event is identified, the total duration of the short - circuit event, or the time integral of the resistance change signal; Generating a warning signal indicating damage to the electrical system in response to one or more of the number of times the short - circuit event is identified exceeding a first specified non - zero threshold, the total duration exceeding a second specified non - zero threshold, or the time integral exceeding a third specified non - zero threshold; Further comprising The resistance change signal is (1) The difference between the voltage drop across the one or more resistive elements determined by the following formula and the product of the value after the second filtering process of the ratio of the voltage drop across the one or more resistive elements to the applied voltage, where the value after the second filtering process is In the above formula, VoltageDeviation(t) is a voltage deviation signal, and V ｇｒｉｄ (t) is the voltage drop, and V(t) is the applied voltage, and ｂａｓｅ is the difference, which is the value after the second filtering process of and (2) The difference between the first product of the voltage drop across the one or more resistive elements determined by the following formula and the second product of the applied voltage and the value after the fourth filtering process of the voltage drop across the one or more resistive elements, where the value after the third filtering process of the applied voltage is In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is the value after the third filtering process of is the difference, which is the value after the fourth filtering process of Either of the above A method characterized by the above. **Claim 6** The method according to claim 5, wherein the electrical system is a power generation braking grid. **Claim 7** A detection device configured to measure the characteristics of a current conducted through one or more resistive elements of an electrical system, which occurs when an applied voltage is supplied from a power source to the electrical system, and a processing assembly configured to determine a resistance change signal determined based on a change in one or more electrical resistances of the one or more resistive elements, A system comprising: The resistance change signal is based on a filtering process using the measured characteristics of the current, The processing assembly is configured to identify a short circuit event based on the resistance change signal, The detection device is configured to measure a voltage drop across the one or more resistive elements, which is used to determine the characteristics of the current and is caused by the current flowing through the one or more resistive elements, The detection device further has a function of a filtering process to exclude the characteristics and / or the applied voltage that occur and end in a short time shorter than a specified time, The detection device also (1) The difference between the voltage drop across the one or more resistive elements determined by the following formula and the product of the value after the second filtering process of the ratio of the applied voltage to the voltage drop across the one or more resistive elements, In the above formula, VoltageDeviation(t) is a voltage deviation signal, and V ｇｒｉｄ (t) is the voltage drop, and V ｂａｓｅ (t) is the applied voltage, where is the value after the second filtering process of and, (2) The difference between the first product of the voltage drop across the one or more resistive elements determined by the following formula and the value after the third filtering process of the applied voltage, and the second product of the applied voltage and the value after the fourth filtering process of the voltage drop across the one or more resistive elements, In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, and V ｇｒｉｄ (t) is the voltage drop, and V ｂａｓｅ (t) is the applied voltage, where is the value after the third filtering process of where is the value after the fourth filtering process of A system configured to measure one or more from the group consisting of these as the resistance change signal.

8. The applied voltage is generated by a traction motor of the vehicle during regenerative braking of the vehicle, The system according to claim 7, wherein the one or more resistive elements include one or more resistors of a regenerative braking grid.

9. The system according to claim 7, wherein the electrical system is a regenerative braking grid.

10. A detection device configured to measure the characteristics of a current conducted through one or more resistive elements of the electrical system, which occurs when an applied voltage is supplied from a power source to the electrical system, and A processing assembly configured to determine a resistance change signal based on a change in one or more electrical resistances of the one or more resistive elements, wherein the resistance change signal is based on a filtering process using the characteristics of the measured current, and the processing assembly is configured to identify a short-circuit event based on the resistance change signal, the processing assembly; A system comprising; The characteristics of the measured current are determined by a voltage drop across the one or more resistive elements caused by the current flowing through the one or more resistive elements; The detection device has a function of a filtering process that excludes the characteristics and / or the applied voltage that occur and end in a short time less than a specified time; The processing assembly monitors one or more of the number of times the short-circuit event is identified, the total duration of the short-circuit event, or the time integral of the resistance change signal, and the number of times the short-circuit event is identified exceeds a specified non-zero threshold, the total duration exceeds a specified non-zero threshold, or the time integral exceeds a specified non-zero threshold, and is configured to generate a warning signal indicating damage to the electrical system in response to one or more of these; The resistance change signal is; (1) The difference between the voltage drop across the one or more resistive elements determined by the following formula and the product of the value after the second filtering process of the ratio of the applied voltage and the voltage drop across the one or more resistive elements with respect to the applied voltage, In the above formula, VoltageDeviation(t) is a voltage deviation signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is, the value after the second filtering process of, the difference, and, (2) The difference between the first product of the voltage drop across the one or more resistive elements and the value after the third filtering process of the applied voltage determined by the following formula and the second product of the applied voltage and the value after the fourth filtering process of the voltage drop across the one or more resistive elements, In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is, the value after the third filtering process of, is, the value after the fourth filtering process of, the difference, Any of these; A system characterized by this.

11. The system according to claim 10, wherein the electrical system is a power generation braking grid.

12. A detection device configured to measure the characteristics of a current conducted through one or more resistors of the electrical system, which is generated by supplying an applied voltage from a traction motor of a vehicle to the electrical system of the vehicle; A processing assembly configured to determine a resistance change signal based on a change in one or more electrical resistances of the one or more resistors of the electrical system; A system comprising: The processing assembly generates the resistance change signal based on a low-pass filtering process using the characteristics of the measured current; The detection device is configured to measure a voltage drop across the one or more resistors caused by the current flowing through the one or more resistors, which is used to determine the characteristics of the current; The detection device further has a function of low-pass filtering to exclude the characteristics and / or the applied voltage that occur and end in a short time less than a specified time; The detection device also (1) The difference between the product of the value after the second low-pass filtering process of the ratio of the voltage drop across the one or more resistors determined by the following formula and the value after the second low-pass filtering process of the ratio of the applied voltage and the voltage drop across the one or more resistors, In the above formula, VoltageDeviation(t) is a voltage deviation signal, and V ｇｒｉｄ (t) is the voltage drop, and V ｂａｓｅ (t) is the applied voltage, is the difference, which is the value after the second low-pass filtering process of and, (2) The difference between the first product of the value after the third low-pass filtering process of the voltage drop across the one or more resistors and the value after the third low-pass filtering process of the applied voltage determined by the following formula and the second product of the value after the fourth low-pass filtering process of the applied voltage and the value after the fourth low-pass filtering process of the voltage drop across the one or more resistors, In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, is the value after the third low-pass filtering process of is the difference, which is the value after the fourth low-pass filtering process of One or more selected from the group consisting of are configured to be measured as the resistance change signal; A system characterized by the above.

13. The system according to claim 12, wherein the electrical system is a power generation braking grid.

14. A detection device configured to measure the characteristics of a current conducted through one or more resistors of an electrical system, which is generated by supplying an applied voltage from a traction motor of a vehicle to the electrical system of the vehicle; A processing assembly configured to determine a resistance change signal based on a change in one or more electrical resistances of the one or more resistors of the electrical system; A system comprising: The characteristics of the measured current are determined by a voltage drop across the one or more resistors caused by the current flowing through the one or more resistors; The resistance change signal is based on a low-pass filtering process using the characteristics of the measured current. The detection device has a low-pass filter function that eliminates the characteristics and / or the applied voltage that occur and end in a short time less than the specified time. The processing assembly further monitors one or more of the number of times a short-circuit event in the electrical system is identified, the total duration of the short-circuit event, or the time integral of the resistance change signal, and responds to one or more of the number of times the short-circuit event is identified exceeding a specified non-zero threshold, the total duration exceeding a specified non-zero threshold, or the time integral exceeding a specified non-zero threshold, by generating a warning signal indicating damage to the electrical system. The resistance change signal is (1) the difference between the voltage drop across the one or more resistors determined by the following formula and the product of the value after the second low-pass filter processing of the ratio of the applied voltage and the voltage drop across the one or more resistors, In the above formula, VoltageDeviation(t) is a voltage deviation signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, where the difference is the value after the second low-pass filter processing of and is (2) the difference between the first product of the voltage drop across the one or more resistors and the value after the third low-pass filter processing of the applied voltage and the second product of the applied voltage and the value after the fourth low-pass filter processing of the voltage drop across the one or more resistors, determined by the following formula where In the above formula, VoltageSquaredDeviation(t) is the deviation squared signal, V ｇｒｉｄ (t) is the voltage drop, V ｂａｓｅ (t) is the applied voltage, the difference is the value after the third low-pass filter processing of and where the difference is the value after the fourth low-pass filter processing of and is either of these. A system characterized by this. **Claim 15** The system according to claim 14, wherein the electrical system is a power generation braking grid.

Images