Temperature-based resistance braking closed loop control

Abstract

This document provides a system comprising: a resistive grid having a resistive element; and a sensor configured to sense conditions indicating the temperature of the resistive element. The system also includes processing circuitry including a memory communicatively coupled to one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the processing circuitry to perform the following operations: determining a speed of an electrically driven machine when resistive braking is applied; determining the temperature of the resistive element of the resistive grid when resistive braking is applied; calculating a maximum resistive braking speed in response to the temperature satisfying a temperature threshold; and a speed controller applying the maximum resistive braking speed to the electrically driven machine to prevent the electrically driven machine from exceeding the maximum resistive braking speed.

Description

Technical Field

[0001] This disclosure relates in general to the field of resistor gate assemblies for resistor braking systems of electrically driven machines, and more specifically to improved systems and methods for operating such resistor gate assemblies. Background Technology

[0002] Resistive grid systems for dynamic braking in machinery, such as electric and diesel-electric locomotives, off-highway machinery, and other heavy equipment, are well-known. An electric drive motor generates current during braking, and the resistive grid system comprises multiple resistive elements for dissipating the generated electricity as heat. Therefore, the resistive grid system can complement friction brakes and minimize wear on the friction braking components of the machine.

[0003] The heat dissipation capacity of a resistive grid is limited by the maximum permissible temperature of the resistive element. Therefore, the heat dissipation capacity of a resistive grid system may be reduced based on the system's component design, environmental conditions around the machine, and the altitude at which the machine operates. Complex models can estimate the utilization of the resistive grid, but failure to properly identify and manage the grid temperature may result in the full capacity of the resistive grid system being underutilized. Improved resistive grid system design and control systems are needed to extend the service life of resistive braking systems and achieve maximum braking capacity under various operating conditions. Summary of the Invention

[0004] The first aspect provided herein relates to an electrically driven machine. The electrically driven machine includes a resistive grid, a resistive element, a sensor, and a controller. The resistive grid includes the resistive element, and the sensor is configured to sense conditions indicating the temperature of the resistive element. The controller is configured to control the resistive braking speed of the electrically driven machine. The controller has at least one processing circuitry including at least one memory coupled to at least one processor. The at least one memory stores instructions therein that, when executed by the at least one processor, cause the at least one processor to perform operations. Specifically, the at least one processor is configured to: determine the resistive braking speed; receive a temperature threshold; determine the temperature of the resistive element; and compare the temperature of the resistive element with the temperature threshold. In response to the temperature satisfying the temperature threshold, the controller calculates a maximum resistive braking speed and prevents the electrically driven machine from exceeding the maximum resistive braking speed.

[0005] In some embodiments, the electric drive machine further includes a speed regulator configured to prevent the electric drive machine from exceeding the maximum resistive braking speed. In some embodiments, the temperature threshold is a predefined temperature below the maximum operating temperature of the resistive gate, and the at least one processor is configured to: determine the rate of change of the temperature of the resistive element; and, in response to the temperature of the resistive element reaching the predefined temperature, control a fan to manage the rate of change of the temperature, thereby preventing the resistive element from exceeding the maximum operating temperature of the resistive gate.

[0006] In some embodiments, the at least one processor is further configured to receive data indicating the thermal mass of the resistive gate. The at least one processor may calculate the maximum resistive braking speed based on the temperature of the resistive element, the rate of change of the temperature of the resistive element, the thermal mass of the resistive gate, and the resistive braking speed of the electric drive machine when resistive braking is applied to the electric drive machine.

[0007] The second aspect provided herein relates to a system for controlling the speed of resistive braking. The system includes: a resistive grid having a resistive element; and a sensor configured to sense conditions indicating the temperature of the resistive element. The system also includes processing circuitry including a memory communicatively coupled to one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the processing circuitry to perform the following operations: (1) determine the speed of an electric drive machine when resistive braking is applied to it; (2) determine the temperature of the resistive element of the resistive grid when resistive braking is applied to it; (3) calculate a maximum resistive braking speed in response to the temperature satisfying a temperature threshold; and (4) apply the maximum resistive braking speed to a speed controller of the electric drive machine to prevent it from exceeding the maximum resistive braking speed.

[0008] In some embodiments, the sensor is a temperature sensor configured to directly sense the temperature of the resistive element. In some embodiments, the condition indicating the temperature of the resistive element is the body insulator temperature. In some embodiments, the processing circuitry is configured to estimate the insulator surface temperature based on the body insulator temperature.

[0009] In some embodiments, the temperature threshold is a predefined temperature below the maximum operating temperature of the resistive gate. In additional embodiments, the processing circuit is further configured to: (1) determine the rate of change of the temperature of the resistive element; and in response to the temperature of the resistive element reaching the predefined temperature; (2) control a fan to manage the rate of change of the temperature, thereby preventing the resistive element from exceeding the maximum operating temperature of the resistive gate. In still other embodiments, the processing circuit is configured to receive data indicating the thermal mass of the resistive gate. In some embodiments, the processing circuit is further configured to calculate the maximum resistive braking speed based on the temperature of the resistive element, the rate of change of the temperature of the resistive element, the thermal mass of the resistive gate, and the speed of the electric drive machine when resistive braking is applied to the electric drive machine.

[0010] The third aspect provided herein relates to a method for controlling the speed of resistive braking. The method includes the following steps: (1) when resistive braking is applied to an electric drive machine, the one or more processors determine the speed of the electric drive machine; (2) when resistive braking is applied to the electric drive machine, the one or more processors determine the temperature of the resistive element of the resistive grid; (3) in response to the temperature satisfying a temperature threshold, the one or more processors calculate a maximum resistive braking speed; and (4) the one or more processors apply the maximum resistive braking speed to a speed controller of the electric drive machine to prevent the electric drive machine from exceeding the maximum resistive braking speed.

[0011] In some embodiments, the method further includes receiving data indicating the temperature of the resistive element by the one or more processors. In still other embodiments, the temperature of the resistive element is an insulator surface temperature, and the method further includes the step of calculating the insulator surface temperature by the one or more processors based on the data indicating the temperature of the resistive element. The method may also include receiving a temperature threshold by the one or more processors, and the temperature threshold may be a predefined temperature below the maximum operating temperature of the resistive gate.

[0012] In some embodiments, the method further includes: determining, by the one or more processors, the rate of change of the temperature of the resistive element; and, in response to the temperature of the resistive element reaching the predefined temperature, controlling a fan by the one or more processors to manage the rate of change of the temperature, thereby preventing the resistive element from exceeding the maximum operating temperature of the resistive gate. In still other embodiments, the method further includes: receiving, by the one or more processors, data indicating the thermal mass of the resistive gate. In some embodiments of the method, the maximum resistive braking speed is calculated by the one or more processors based on the temperature of the resistive element, the rate of change of the temperature of the resistive element, the thermal mass of the resistive gate, and the speed of the electric drive machine when resistive braking is applied to the electric drive machine.

[0013] The present invention is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features, and advantages of the apparatus or process described herein will become apparent from the detailed description set forth herein in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements. Attached Figure Description

[0014] Figure 1 This is a side view of a machine according to an embodiment of the present disclosure;

[0015] Figure 2 According to the embodiments, it is used for Figure 1 A schematic diagram of the electric drive of the machine.

[0016] Figure 3 This is a perspective view of a modular resistive gate system according to an embodiment.

[0017] Figure 4 yes Figure 3 An exploded view of the modular resistive grid system.

[0018] Figure 5 This is a perspective view of a modular resistive gate assembly according to an embodiment.

[0019] Figure 6 According to the embodiments Figure 5 A perspective view of the modular resistor gate of the modular resistor gate assembly.

[0020] Figure 7 This is a perspective view of a resistive element according to an embodiment.

[0021] Figure 8 This is a schematic diagram of a system for controlling the speed of a resistor braking according to an embodiment.

[0022] Figure 9 This is an observation from plane AA according to the embodiment. Figure 7 A perspective view of a portion of a resistive element.

[0023] Figure 10 This is a flowchart of a method for controlling the braking speed of a resistor according to an embodiment. Detailed Implementation

[0024] Before turning to the accompanying drawings, which illustrate certain embodiments in detail, it should be understood that this disclosure is not limited to the details or methods described in the specification or illustrated in the drawings. It should also be understood that the terminology used herein is for descriptive purposes only and should not be considered limiting.

[0025] Electric drive machine

[0026] Figure 1 The diagram schematically illustrates a machine 100 in which the disclosed embodiments may be implemented. Machine 100 can be generally described as any machine having an electric drive (which may be connected to one or more drive wheels). Machine 100 may include vehicles such as diesel locomotives, subway trams, off-highway trucks, or vehicles used for mining, construction, quarrying, and other applications. However, it will be apparent that any other vehicle having an electric drive or purely electric arrangement may be included in machine 100.

[0027] For the purposes of this disclosure, Figure 1 In this embodiment, machine 100 is exemplified as an off-highway truck. Machine 100 may include a chassis 102 for supporting various components of machine 100. Machine 100 may include a tiltable body 104 supported on chassis 102. Chassis 102 may also support an operator's cab 106, which is defined as an enclosed space. An operator in operator's cab 106 can control various functions of machine 100 by issuing various operator commands using control devices such as joysticks, levers, and touch-screen user interfaces.

[0028] The machine 100 may also include a set of drive wheels 108 for propulsion. In an embodiment, a set of idler wheels 110 may also be provided to allow the machine 100 to turn in different directions. Furthermore, the machine 100 may include an articulated chassis for steering. The set of drive wheels 108 and the set of idler wheels 110 may together serve as a ground engagement member of the machine 100. Figure 1 As illustrated, machine 100 also includes a modular resistor grid system 111 located adjacent to the operator's cab 106 within machine 100. However, it will be apparent that the modular resistor grid system 111 can be located in any position based on the design and available space within machine 100.

[0029] The machine 100 disclosed herein may be an electric motor with an electric drive 112. The electric drive 112 can provide electricity to drive various components in the machine 100. In embodiments, the electricity may be generated on-board by a generator, alternator, or other power generation device, which may be driven by an engine or any other power source. Alternatively, the electricity may not be generated on-board, but may be supplied externally from an overhead conductor via a pantograph, battery, series of capacitors, etc., to drive the machine 100.

[0030] In the illustrated embodiment, the electric drive 112 includes a power source 114, which may be an engine, such as an internal combustion engine (e.g., a diesel engine, gasoline engine, natural gas engine, etc.). The power source 114 can provide output torque at an output shaft 116 in the machine 100. The output shaft 116 can be connected to a generator 118, which may be a multiphase alternating current (AC) synchronous alternating current generator. During operation, the output shaft 116 drives the rotor of the generator 118 to rotate to generate electricity, for example, in the form of alternating current (AC). This generated electricity can be used to operate multiple drive motors 120, which are coupled directly or via intermediate components to the set of drive wheels 108. For the purposes of this disclosure, the drive motors 120 may be variable speed, reversible AC motors.

[0031] Electric drive and dynamic braking system

[0032] Figure 2 A schematic diagram of the electric drive 112 is illustrated. The electric drive 112 of this disclosure can be a direct series drive. Figure 2 The arrangement of various components of the electric drive 112 in the machine 100 according to an embodiment is illustrated. In this schematic diagram, the direction of power flow in the system is indicated by arrows. Solid arrows indicate power flow when the machine 100 is being propelled. Conversely, the power flow of the machine 100 during braking mode is... Figure 2 The dashed arrows represent the components of the electric drive 112, while the dotted arrows represent the control circuit connections between the various components.

[0033] Those skilled in the art will understand that generator 118 can generate electricity in the form of alternating current (AC). This electricity can be supplied to rectifier 122 and converted to direct current (DC). The rectified DC electricity can then be converted back to AC electricity by inverter circuit 124. Inverter circuit 124 can selectively adjust the frequency and / or pulse width of its output, allowing drive motor 120 connected to the output of inverter circuit 124 to operate at a variable speed. In embodiments, multiple inverter circuits 124 can be configured to connect to drive motor 120 in machine 100.

[0034] Figure 2A dynamic braking system 200 for machine 100 is also illustrated. The dynamic braking system 200 can be connected to the drive motor 120 of machine 100. Specifically, the dynamic braking system 200 can be operably configured to be connected to the inverter circuit 124 in machine 100. The dynamic braking system 200 can be configured to slow the propulsion of machine 100 during braking mode according to operator commands in machine 100.

[0035] According to this disclosure, the dynamic braking system 200 may include a control unit 202, which may be, but is not limited to, a combination of hardware components, computing devices or other processing equipment and memory (such as random access memory (RAM), read-only memory (ROM), flash memory, data structures, etc.). The control unit 202 may be configured to execute instructions (e.g., the processing equipment may be configured to execute instructions stored in the data structures of the control unit 202). The control unit 202 may be configured to receive operator commands from the machine 100. Furthermore, the control unit 202 may determine whether to place the machine 100 into braking mode based at least in part on the operator commands. To initiate braking of the machine 100, the control unit 202 may generate a braking signal (illustrated by dashed lines) for the inverter circuit 124. The dashed arrows indicate optional signals, inputs, or data 211 that the control unit 202 may receive from the modular resistive grid system 111 during operation.

[0036] The braking signal can be received by the inverter circuit 124 in machine 100. The braking signal can carry a command to reverse the torque polarity of the drive motor 120. This causes the drive motor 120 to act as a generator, thereby using mechanical power in the form of rotational energy from the set of drive wheels 108 to generate electricity. This electricity can be supplied back to the electric drive 112 in machine 100.

[0037] The dynamic braking system 200 can also be configured to provide regenerative braking in the machine 100. For this purpose, the dynamic braking system 200 may include an energy storage unit 204. The energy storage unit 204 may include a battery, multiple capacitors, etc., which are configured to be connected to the drive motor 120 in the electric drive 112. As during braking mode, the drive motor 120 can generate electricity, which the energy storage unit 204 can store for later use by the machine 100.

[0038] This disclosure applies to many machines commonly used in mines, construction sites, and quarries, such as large off-highway trucks, such as dump trucks. Machine 100 can have a high payload capacity and a travel speed of several miles per hour when fully loaded. Machine 100 can also be required to operate in a variety of environments, at a variety of altitudes, and climb steep slopes in dry or wet conditions.

[0039] Typically, friction brakes coupled to the set of drive wheels and idler wheels are used to stop or slow down such machines. These friction brakes are effective, but can wear out after prolonged use. To overcome this, the dynamic braking system 200 of the machine 100 of this disclosure can operate in combination with these friction brakes, or independently. The dynamic braking system 200 can supplement these friction brakes in the machine 100 and thus help reduce wear on such brakes.

[0040] The dynamic braking system 200 can put the machine 100 into braking mode according to operator commands. Specifically, the operator commands can be received by the control unit 202 in the dynamic braking system 200. The control unit 202 generates a braking signal that is at least partially determined by the operator commands. This determination or calculation can be based on various operating parameters of the machine 100, such as current speed, current payload, acceleration, desired speed, etc.

[0041] Subsequently, the braking signal can be received by the inverter circuit 124 in the electric drive 112 of machine 100. In braking mode, the electric drive 112 can switch the torque polarity of the drive motor 120, causing the drive motor 120 to act as a generator. In this mode, the drive motor 120 can use the power from the set of drive wheels 108, thereby ultimately releasing the mechanical energy of the set of drive wheels 108 and achieving deceleration or braking of machine 100. In addition, the drive motor 120 (consuming the mechanical power of the set of drive wheels 108) can generate electricity in the electric drive 112.

[0042] The generated electricity can be fed to the dynamic braking system 200 in the electric drive 112. The generated electricity (which can be in AC form) can be fed via inverter circuit 124, which converts AC power to DC power. In an embodiment where the machine 100 has regenerative braking, a portion of the generated electricity can be supplied to the modular resistive grid system 111 for heat dissipation, and the remainder of the generated electricity can be supplied to the energy storage unit 204 for subsequent use by the machine 100.

[0043] Modular resistive grid system

[0044] The dynamic braking system 200 may include a modular resistive grid system 111. The modular resistive grid system 111 may dissipate some or all of the generated electricity as heat. Figure 3 A perspective view of a modular resistive gate system 111 according to aspects of this disclosure is illustrated. Figure 4 Examples Figure 3 An exploded view of the modular resistive grid system.

[0045] refer to Figure 3 and Figure 4 The modular resistor grid system 111 includes a mounting bracket 302, a fan 310, and a modular resistor grid assembly 400. The mounting bracket 302 can be permanently or removably coupled to the machine 100. The mounting bracket 302 provides a support structure on which other components of the modular resistor grid system 111 can be secured, connected, and / or coupled to the dynamic braking system 200 of the machine 100. The mounting bracket 302 may include a frame 304 and one or more brackets 306. The frame 304 may include rigid support members (such as rods, rails, columns, tracks, or other suitable elements) to secure components of the modular resistor grid system 111 to the machine 100. The brackets 306 may be selectively movable, such that one or more brackets 306 can be fastened along the frame 304 to a first position, released to slide along the length of the frame 304 to a second position, and then fastened to secure the bracket 306 in the second position. The bracket 306 may also include a mounting feature 308 configured to align with or abut against components of the modular resistor grid system 111, such that these components can be fastened together by bolts, welds, or other suitable fasteners. For example, according to aspects of this disclosure, in Figure 3 and Figure 4 In this configuration, a movable bracket 306 is coupled to a mounting feature 308, which is shaped to fit the cylindrical profile of the modular resistor grid system 111. In this way, multiple modular resistor grid assemblies 400 with variable axial length L can be coupled to the mounting member 302 by sliding and securing the movable bracket 306 along the frame 304 as needed.

[0046] The modular resistive grid system 111 also includes a fan 310. The fan 310 is configured (e.g., during the resistive braking mode of the machine 100) to blow cooling air through the modular resistive grid assembly 400 to dissipate heat. The fan 310 may include a blade assembly 312 configured to direct air toward or through the modular resistive grid assembly 400 as the blade assembly 312 rotates. A power source 314 (e.g., a motor, battery, etc.) can power the fan 310, and a hub assembly 316 can direct air toward the modular resistive grid assembly 400 and / or enclose and protect components of the fan 310.

[0047] The modular resistive grid system 111 includes a modular resistive grid assembly 400. The modular resistive grid assembly 400 facilitates resistive braking by receiving power from the machine 100 and dissipating that power as heat. In some embodiments, the modular resistive grid assembly 400 may be formed as a single unit, or may be formed from a single modular resistive grid. In other embodiments, the modular resistive grid assembly 400 may be formed by coupling a plurality of modular resistive grids 402 together (e.g., see discussion below). Figure 5 and Figure 6 The modular resistor gate assembly 400 includes a housing 404 that provides support for the various components of the modular resistor gate system 111. Figures 3 to 5 In the illustrated example, the housing 404 has a cylindrical shape with an inner wall 406 and an outer wall 408. The housing 404 can be of any shape and can be divided into one or more modular segments. For example, the housing 404 of a modular resistor grid assembly 400 can be formed by coupling two or more modular resistor grids 402 together, each modular resistor grid having a housing 404 that encloses one or more resistive elements 410. The modular resistor grid 402 can be cylindrical, semi-cylindrical, quarter-circular, wedge-shaped, triangular, or other suitable shapes. The number of sub-segments of the housing 404 and the number of individual modular resistor grids 402 that can be coupled together to form the modular resistor grid assembly 400 can vary depending on space constraints in the machine 100.

[0048] For example, Figure 5 and Figure 6 An embodiment of a modular resistor gate assembly 400 is illustrated, which is divided into four quarter-circular modular resistor gates 402, which are assembled together in machine 100. Both the modular resistor gate assembly 400 and the modular resistor gates 402 include at least one resistive element 410 disposed between the inner wall 406 and the outer wall 408 of the housing 404. The modular resistor gate assembly and / or the modular resistor gate 402 may include two or more resistive elements 410 (e.g., multiple resistive elements 410) tightly packaged in a stacked configuration with an end-to-end orientation. The resistive elements 410 may be uniformly arranged in the housing 404 to maintain air gaps between them. This uniform spacing ensures adequate cooling airflow between the resistive elements 410 in the modular resistor gate system 111. Furthermore, one or more cooling air vents may be provided in the housing 404 for circulating cooling air within the modular resistor gate system 111.

[0049] Figure 7A resistive element 410 according to an embodiment is illustrated. The resistive element 410 includes a first insulator 412, a second insulator 414, and one or more resistive plates 416 mounted to the first insulator 412 and the second insulator 414. In the illustrated example, the resistive plates 416 are mounted between the first insulator 412 and the second insulator 414, which can then be fixed to the inner wall 406 and outer wall 408 of the housing 404 of the modular resistive grid assembly 400 and / or the modular resistive grid 402. Furthermore, one or more resistive elements 410 can be arranged in one or more rows, substantially parallel to each other and arranged in a close face-to-face relationship, thereby forming an axial airflow path therebetween. The plurality of resistive plates 416 of the resistive element 410 can be connected in series within each modular resistive grid 402 and / or modular resistive grid assembly 400 to provide a continuous current path between the input terminal 419 and the output terminal 420 of the modular resistive grid 402 and / or the modular resistive grid assembly 400 (see [link to documentation]). Figure 5 and Figure 6 For this purpose, conductive members can be provided in the housing 404 to electrically connect two or more resistor plates 416 in the modular resistor grid system 111. The conductive members can be conductive wires, welded parts, etc. The resistive elements 410 can be connected in such a way that the modular resistor grid system 111 can have two current circuits (i.e., a contactor power supply circuit and a chopper power supply circuit).

[0050] As illustrated, the first insulator 412 and the second insulator 414 can be in the shape of a block made of an insulating material, such as silicon-bonded laminated mica, ceramic, glass-reinforced material, etc. However, any other material with insulating properties can be used to form the first insulator 412 and the second insulator 414. The first insulator 412 can be secured to the outer wall 408 of the housing 404 by some fastening member, such as nuts and bolts, screws, etc. The second insulator 414 can be secured to the inner wall 406 of the housing 404 in a similar manner. The first insulator 412 and the second insulator 414 can each include one or more holes 418 formed in the first insulator and the second insulator. Furthermore, the holes 418 may not extend through the first insulator 412 or the second insulator 414 and can be configured to receive and mount a resistor plate 416 between the first insulator 412 and the second insulator 414.

[0051] The resistor plate 416 may be formed from a continuous strip of resistive material, such as stainless steel. The resistor plate 416 may include a body portion 421 extending along a longitudinal direction XX′ of the resistor plate 416. In one embodiment, the resistor plate 416 may also include a series of folded portions 422 disposed on opposite longitudinal sides of the body portion 421 of the resistor plate 416. In some configurations, the resistor plate 416 may extend along the longitudinal direction XX′ in the range of about 150 mm to about 200 mm. In a specific example, the resistive element 410 may have a length of about 175 mm. The resistor plate 416 may have a pointed portion 424 disposed at an end 426 remote from the body portion 421. Alternatively, the resistor plate 416 may include two or more pointed portions 424 disposed from both ends 426. The pointed portions 424 of the resistor plate 416 may be adapted to be received in apertures 418 of a first insulator 412 and a second insulator 414. The apertures 418 may provide clearance therein for movement of the pointed portions 424. This allows the resistor plate 416 to move along the longitudinal direction XX′ within the resistor element 410 during thermal expansion and contraction.

[0052] During the resistor braking mode, the generated power can enter the modular resistor grid system 111 via input terminal 419 and flow through the resistor plate 416 in the resistor element 410 of the modular resistor grid system 111 as heat dissipation. Specifically, the heat is mainly generated by the main body portion 421 of the resistor plate 416. This generated heat can radiate to the first insulator 412 and the second insulator 414, raising the temperature of the first insulator 412 and the second insulator 414 in the resistor element 410, which in turn can raise the temperature of the housing 404. According to industry standards, the normal continuous operating temperature of the first insulator 412 and the second insulator 414 is in the range of 300 to 400 degrees Celsius. For short intervals, the temperature of the first insulator 412 and the second insulator 414 may reach higher values ​​due to surges, but if the temperature rises above the critical or maximum operating temperature for an extended period of time, the lifespan of the first insulator 412 and the second insulator 414 may be significantly shortened. In addition, the mechanical stability of the resistor plate 416 may be affected, causing the resistor plate 416 to bend and ultimately leading to the rapid failure of the dynamic braking system 200.

[0053] Temperature-based resistance braking closed-loop control

[0054] Continue to refer to Figures 2 to 7During operation, the modular resistive grid system 111 has an energy dissipation capacity that can be expressed as a power capacity. For example, the power capacity of the modular resistive grid system 111 can be 1 MW. The power capacity of the modular resistive grid system 111 can vary depending on the geometry and characteristics of the resistive grid system and the operating conditions of the system. As a non-limiting example, the power capacity of the modular resistive grid system 111 in dissipating energy can depend on the operating conditions of the fan 310, the ambient air temperature, the ambient air density, the temperature of the resistive element 410, etc.

[0055] For example, the power capacity of the modular resistive gate system 111 can be reported or measured as either continuous power capacity or transient power capacity. The continuous power capacity of the modular resistive gate system 111 can be measured when the resistive element 410 is at its maximum sustainable temperature T. max The power capacity of the modular resistive gate system 111 may be limited by the maximum temperature T that the resistive element 410 can maintain. max This maximum temperature can depend on the material and geometry of the resistive element. To maximize the utilization of the resistive braking capacity, the modular resistive grid system 111, operating in continuous power capacity mode, can keep the resistive element 410 at a near-steady-state temperature (e.g., at T0). max Or near T. Conversely, below T max Temperature (e.g., T) max 50%, T max Operating at 70% (of its capacity) indicates that machine 100 failed to utilize the originally available resistive braking capacity. Therefore, below T... max Operating at temperatures below T is generally less efficient than operating at T max It operates efficiently at or near a steady-state temperature. At steady-state temperature, the modular resistive grid system 111 dissipates energy as heat at approximately the same rate as the energy supplied to the system as charge. Furthermore, by utilizing the full resistive braking capacity, the machine can operate at maximum resistive braking speed. Depending on various specific embodiments, the continuous power capacity of the modular resistive grid system 111 can depend on several variables, including but not limited to the length of the electrical path provided by the resistive elements, the resistive grid material, the thermal mass of the resistive grid system, the fan duty cycle, and convection factors (such as the angle and surface geometry of the lateral airflow presented by the grid elements to the fan operation).

[0056] Thermal models can be used to estimate the maximum resistive braking speed based on these variables. For example, such models could use braking speed as an independent variable and attempt to predict the resulting temperature of the resistive grid system and / or resistive element 410 based on various conditions such as braking speed, road gradient, operating altitude (e.g., sea level, approximately 5,000 ft above sea level, 10,000 ft above sea level), and other variables. However, these models can be computationally intensive, requiring significant resources and tuning (e.g., testing under various such conditions, such as different altitudes and gradients), and may result in the inability to utilize the full resistive braking capacity of the machine and a lower resistive braking speed. For example, a model might predict that a braking speed of 20 kph will result in a temperature close to T under conditions such as 5,000 ft above sea level, a specific road gradient, a specific atmospheric pressure, and a specific ambient temperature. max Therefore, the machine should not exceed 20 kph. However, without directly measuring the temperature of the modular resistive grid system and / or the resistive plate 416, the estimated temperature can be lower than T. max This means that the machine will reach T max Previously, it could travel at 25 kph, 30 kph, etc. Therefore, the apparatus, system, and method discussed in this paper utilize the measurement of the critical temperature of the resistive grid (whether direct or indirect) to optimize the resistive braking capacity for each transport cycle. By monitoring the temperature of the resistive grid system, the machine can achieve [specific speeds / capacities] at [specific temperatures]. max It operates at or near the location, and the machine can "adjust" the braking speed of the resistor so that the temperature does not exceed T. max In this way, the resistive braking speed can be optimized / maximized for each cycle at any slope / altitude without feeding multiple measurements into a computationally intensive empirical model.

[0057] refer to Figure 8 A schematic diagram of a control circuit 500 for a resistive braking system specifically implemented according to an example of this disclosure is provided. When the machine 100 is in resistive braking mode or performing resistive braking operation, the control circuit 500 can determine the temperature of the resistive grid. The control circuit 500 can monitor the temperature and determine the maximum resistive braking speed at which the temperature of the resistive element is close to but does not exceed the maximum operating temperature (T0) of the resistive grid system. max The control circuit 500 can be configured to provide control of the resistance braking system of the vehicle (including the power source, drive motor, inverter, and resistance grid system) as previously described, while receiving data on the operating temperature of components or portions of the resistance grid system.

[0058] like Figure 8As shown, the control circuit 500 may include a control unit 510, an inverter circuit 512, and a sensor 520. The control circuit 500 includes one or more processors 504 and a computer memory 502. In some embodiments, the control circuit 500 includes a secondary data source 518 and / or a display 516 for displaying data associated with the resistor braking operation. For example, the display may indicate the currently measured temperature of the resistor braking system, the temperature of the resistive element 410, the temperature of the housing 404, the current braking speed, the maximum braking speed, the rate of temperature change (e.g., the degree of heating / cooling of the resistive grid), the maximum operating temperature of the resistive grid, etc. In other embodiments, the display 516 may provide a thermal map of the modular resistive grid system, the power level of the fan 310, or other data associated with resistor braking.

[0059] Control unit 510 may be, but is not limited to, a set of instructions stored in computer memory 502, one or more processors 504 configured to execute the set of instructions, random access memory (RAM), read-only memory (ROM), flash memory, data structures, etc. Control unit 510 may also share components with, be identical to, communicate with, or otherwise interoperate with the control unit 202 of the dynamic braking system and / or the engine control unit (ECU) of machine 100. Control unit 510 is configured to receive and output signals. Control circuitry 500 is electrically coupled to sensor 520, which is configured to collect data or transmit signals 540 indicating the temperature of one or more portions of the resistive grid system 514 (e.g., modular resistive grid system 111), such as resistive element 410.

[0060] The control unit 510 can also be configured to transmit a braking signal 550 to the inverter circuit 512. The braking signal can be received by the inverter circuit 512 in the vehicle. The braking signal can carry a command to reverse the torque polarity of a drive motor (not shown) coupled to the inverter circuit 512, thereby providing braking to the vehicle and generating charge in the drive motor. Excess charge can be directed to a resistor grid system for heat dissipation or to a battery for storage.

[0061] As a non-limiting example, sensor 520 may be a sensor configured to directly measure the temperature of the resistive grid system 514. For example, sensor 520 may include a thermocouple, digital temperature sensor, infrared detector, thermopile sensor, resistance temperature detector (RTD), or negative temperature coefficient thermistor. Sensor 520 may provide control unit 510 with a signal 540 indicating one or more temperatures associated with one or more resistive elements 410. Measuring multiple resistive element locations increases data redundancy and may also help identify hot spots in the resistive grid. Such hot spots may indicate conduction or convection problems in the resistive grid. Alternatively or additionally, the temperature sensor may provide information corresponding to the temperature of other parts of the resistive grid system. For example, the temperature of the resistive insulator or grid cover may also be of interest and therefore can be measured. Specifically, sensor 520 may be located at or near the surface of the body of the first insulator 412 and / or the second insulator 414. In this way, sensor 520 may be configured to measure the surface temperature or body insulator temperature to indicate the current operating temperature of the resistive grid system and / or resistive elements 410. In some embodiments, control circuitry 500 may be configured to determine or estimate the temperature of resistive plate 416 based on a lookup table, algorithm, or other process that utilizes known thermodynamic properties of the insulator (e.g., second insulator 414) and various boundary conditions (e.g., ambient temperature, distance and contact between the insulator and resistive plate 416, rate of change of the bulk insulator temperature, etc.). In still other embodiments, sensor 520 may directly measure the temperature of resistive plate 416 by coupling at or near resistive plate 416.

[0062] Go to Figure 9 This shows the view from plane AA. Figure 7 A perspective view of a portion of the resistive element, illustrating an example placement of sensor 520. (As shown) Figure 9As shown, sensor 520 can be directly mounted in the second insulator 414, located on the underside of the body and within a hole defined at the bottom of the second insulator 414. In other embodiments, sensor 520 can be coupled to any other surface of the second insulator 414 and / or the first insulator 412 (e.g., against or adjacent to a sidewall, against or adjacent to a flange portion, at the top surface adjacent to the hole 418, at a distance of 1 mm to 5 mm from the insulator, at a distance of 1 mm to 5 mm from the resistor plate 416, etc.). Therefore, by positioning sensor 520 at or near the insulator, the temperature of the resistor grid system can be monitored during vehicle operation. In this way, the operator and / or control circuitry 500 can determine how close the resistor grid system is to operating at its maximum operating temperature and adjust the resistive braking speed accordingly to increase or decrease the temperature of the resistor grid system. As explained herein, feedback from sensor 520 enables the control unit to control the resistive braking mode to maintain a T-mode for an extended period or for substantially the entire duration of the resistive braking mode. max The vehicle or machine 100 operates at or near the temperature. Therefore, the vehicle or machine 100 can optimize its resistance braking speed by maximizing it without overheating or causing thermal damage to the resistance grid system.

[0063] In other embodiments, sensor 520 may be one or more virtual sensors that indirectly measure temperature by collecting data that can be used to determine, calculate, or estimate the temperature of the resistive grid system and / or resistive element 410. For example, sensor 520 may be arranged, positioned, located, or otherwise situated to sense the temperature at the inlet and outlet of a cooling air vent, thereby determining the inlet and outlet temperatures of the cooling air before and after it travels through the resistive grid system. Other sensors (e.g., airflow sensors, humidity sensors, etc.) may be used to estimate the temperature of the resistive element based on changes in the temperature of the cooling air. Other configurations of various sensors, readily apparent to those skilled in the art, are also contemplated within this disclosure. Control unit 510 may be configured to determine the temperature of resistive grid system 514 based on other data or sensed conditions such as ambient air temperature, ambient air density, ambient air pressure, fouling of the resistive element, the altitude at which the vehicle is operating, or the planned route of the vehicle. This list of potential conditions is not intended to be exclusive, and other variables may be considered when determining the operating temperature of resistive grid system 514.

[0064] Continue to refer to Figures 2 to 8Control unit 510 is configured to determine the resistance braking speed of machine 100 during resistance braking operation (e.g., using one or more processors 504 and memory 502). For example, control unit 510 may receive a signal 555 from electric drive 112 indicating the current speed of the vehicle (e.g., via one or more sensors configured to collect data from electric drive 112, via accelerometers, speedometers, etc.). In another example, sensors may determine the rotational rate of one or more wheels 108, 110, thereby allowing control unit 510 to determine the resistance braking speed. Control unit 510 may be configured to detect or identify resistance braking operation based on sensing or receiving signals indicating that the brakes of machine 100 have been applied, power is being dissipated through resistance grid system 514, etc.

[0065] The control unit 510 is also configured to receive a temperature threshold for comparison with the temperature of the machine 100. For example, the temperature threshold could be below the maximum operating temperature T of the resistive grid system. max The predefined temperature. The temperature threshold can be close enough to T. max (For example, within 5%, 10%, 15%, etc.), so that the resistive gate system 514 can be approaching T. max Or otherwise approaching the temperature maintained at T max Or its vicinity, and a steady-state condition where the resistive braking speed is optimized / maximized. As the temperature rises, the control unit 510 can collect empirical data regarding the rate of temperature change, the speed of the machine 100, etc. Alternatively, the control unit 510 can monitor only the temperature of the machine and compare that temperature to a temperature threshold. By comparing the machine temperature to the temperature threshold and determining that the temperature has reached or exceeded the threshold, the control unit 510 can begin monitoring the rate of temperature increase, the power level of the cooling fan, the speed of the machine, etc. Therefore, once the temperature reaches the temperature threshold, the control unit 510 can determine the maximum resistive braking speed, the power level of the operating fan, etc., thereby providing the maximum resistive braking speed while maintaining the temperature at T. max or its vicinity. In some embodiments, the temperature threshold may be below T. max The temperature range or a temperature range near it, defined by an upper and lower temperature limit. For example, the maximum operating temperature could be 400°C. In some embodiments, the temperature threshold could be a temperature range defined by a lower limit of 300°C and an upper limit of 375°C. Once the control unit 510 measures a temperature within this range (e.g., the temperature of the resistive grid system 514 reaches 300°C), the control unit 510 can begin monitoring the rate of temperature change, machine speed, and other factors to determine the temperature to be within T... max Under the condition of maintaining the operating temperature at T maxThe steady-state velocity at or near the location.

[0066] In some embodiments, control unit 510 may optionally be configured to receive additional signals 570 from secondary data source 518 to receive speed and / or temperature thresholds of machine 100. Secondary data sources may include, but are not limited to, remote or local databases or servers, other vehicles, processors, memory, and / or local or remote sensors. For example, control unit 510 may receive signals 570 corresponding to vehicle speed, thermal mass of a resistive grid system fitted to the vehicle, temperature thresholds associated with the vehicle's resistive grid system, altitude at which the vehicle is operating, time of day, information about the vehicle's planned route, etc. Although a single source 518 is shown, it should be understood that each of these data signals may be provided by a separate sensor or other data source, such as a temperature sensor configured to measure the temperature of the ambient air around the vehicle or an altimeter configured to measure the altitude at which the vehicle is operating. It should also be understood that a single source may provide multiple data points. For example, a remote server may send signals providing data about the vehicle's altitude, the gradient of the vehicle's path, and the vehicle's speed.

[0067] The control unit 510 can also be configured to control the speed or power level supplied to the fan 310. In this way, the control unit 510 can monitor and manage the temperature of the resistive grid system 514 and maintain the resistive grid system 514 at or near its maximum operating temperature during resistive braking mode. For example, if the control unit determines during resistive braking mode that the current braking speed is too high and there is a risk of exceeding the maximum operating temperature of the resistive grid system 514, the control unit can send a signal 555 (e.g., to the speed controller of the electric drive 112) to decelerate the vehicle, and / or can send a signal 580 to the fan 310 to increase the fan speed, thereby increasing the cooling rate and reducing the temperature of the resistive grid system 514, or bringing the resistive grid system 514 to a steady-state temperature and braking speed.

[0068] Control circuitry 500 can be configured to provide an output signal 560 to interface 516. Therefore, information determined, calculated, derived, identified, or otherwise present in control unit 510 can be transmitted to other device 516 via output signal 560. In some embodiments, interface 516 is a user interface such as a graphical display. As a non-limiting example, the display can be positioned in the driver's cab to show the vehicle operator the maximum resistance braking speed at the current gradient.

[0069] Go to Figure 10A method 600 for controlling the speed of resistive braking according to an embodiment is shown. In a first step 610, when resistive braking is applied, one or more processors on the vehicle can determine the speed of the electric drive machine from a secondary data source 518, etc. For example, control unit 510 can receive a signal from electric drive 112 indicating the current speed of the vehicle, and can detect a braking signal transmitted to inverter circuit 512 for initiating / causing resistive braking operation. During resistive braking mode, the speed of the vehicle can be recorded and stored by control unit 510 over time, stored as an average speed, or otherwise monitored.

[0070] At step 620, when resistive braking is applied to the electrically driven machine, the one or more processors may determine the temperature of resistive element 410 or another portion of resistive grid system 514. As described above, the temperature may be measured by various physical sensors (e.g., directly measuring temperature) or virtual sensors (e.g., indirectly measuring temperature) located near or inside the resistive grid system, on the vehicle, etc. For example, sensors may include thermocouples, digital temperature sensors, infrared detectors, thermopile sensors, resistance temperature detectors, or negative temperature coefficient thermistors. In other embodiments, sensors may include secondary sensors or other data sources (e.g., data sources providing information other than temperature), against which the temperature of the resistive grid system is calculated. For example, control unit 510 may receive information indicating the thermal mass of the resistive grid system, the composition of the resistive grid system, the flow rate of cooling air, the rate of temperature change associated with the resistive grid system 514, or other suitable measurements used to estimate / calculate the temperature of the resistive grid system 514.

[0071] At step 630, in response to the temperature of the resistive grid system 514 meeting a temperature threshold or after the temperature of the resistive grid system has met the temperature threshold, the control unit 510 calculates the maximum resistive braking speed. In some embodiments, prior to this step, the control unit 510 may receive the temperature threshold, which, as discussed above, may be a temperature or temperature range below the maximum operating temperature of the resistive grid system 514. In other embodiments, the temperature threshold may be pre-programmed or predefined on the control unit 510 (e.g., stored in memory 502 and not received during vehicle operation). At this step, once the operating temperature reaches the temperature threshold, the control unit 510 may begin monitoring or otherwise collecting data from the temperature channel associated with the operating temperature of the resistive grid system 514. The control unit 510 may allow the temperature to rise until it reaches the upper limit of the temperature threshold (e.g., a temperature limit). The control unit may then receive the machine speed at that temperature limit and allow the machine to operate at that speed. In this way, the control unit can collect empirical data based on the rate of temperature rise of the resistive grid system 514 during braking operation and the thermal mass of the resistive grid system 514, and initiate additional braking commands or otherwise adjust the vehicle speed or cooling fan power to ensure that the operating temperature does not exceed the maximum operating temperature. For example, as the temperature of the resistive grid system 514 approaches the maximum operating temperature, the control unit 510 can be configured to calculate the rate at which the rate of temperature change of the resistive grid system becomes zero.

[0072] The method may further include step 640, which involves determining the rate of temperature change of the resistive element 410 or a portion of the resistive grid system 514. In some embodiments, the control unit 510 may directly measure or calculate the rate of temperature change of the resistive grid system 514. In other embodiments, the control unit may receive data indicating the rate of temperature change (e.g., from a secondary data source 518). Once the rate of temperature change of the resistive grid system 514 has been determined, the control unit 510 may use other data (e.g., data indicating the thermal mass of the resistive grid) to calculate whether the machine 100 is operable and will not exceed the T0 of the resistive grid system 514. max The maximum speed. In other embodiments, at least one processor of the control circuit 500 is configured to calculate the maximum resistive braking speed based on the temperature of the resistive element, the rate of change of the temperature of the resistive element, the thermal mass of the resistive grid system 514, and the resistive braking speed of the electric drive machine when resistive braking is applied to the electric drive machine.

[0073] At step 650, control circuit 500 and / or control unit 510 can control a fan (e.g., fan 310) to manage the rate of temperature change, thereby preventing the resistive element from exceeding the maximum operating temperature of the resistive gate. For example, control unit 510 can base its control on the operating temperature of the resistive gate and the temperature at T... maxThe maximum resistance braking speed is determined by the zero rate of change of the resistance grid temperature at or near the point where the fan operates. Therefore, the control unit 510 can change the power of the fan 310 and determine that the vehicle can travel at a higher speed and maintain that steady-state temperature. In this way, the control unit 510 can be configured to determine the maximum resistance speed given the thermal mass of the resistance grid system 514, the system's operating temperature at a specific speed, and the power of the fan available to be allocated to the resistance grid system 514.

[0074] At step 660, control circuitry 500 and / or control unit 510 can prevent the electric drive machine from exceeding the maximum resistive braking speed. For example, in some embodiments, control unit 510 and / or control circuitry 500 signal a speed governor of the electric drive machine configured to prevent the electric drive machine from exceeding the maximum resistive braking speed. In some embodiments, the speed governor can be configured as part of the electric drive 112. In other embodiments, control unit 510 can selectively activate / deactivate the vehicle's friction braking system to adjust the speed to the maximum resistive braking speed. In still other embodiments, control unit 510 can automatically adjust the vehicle's cruise control system to increase the speed to the maximum resistive braking speed.

[0075] It should be understood that the methods disclosed in this article are not limited to exactly [specific methods]. Figure 10 The steps shown do not necessarily need to be performed in the order described. Multiple iterations of a step can be performed before or after performing another step. In some embodiments, the determination of the rate of change of the temperature of the resistive element 410 and the control of the fan 310 are not performed. In other embodiments, the determination of the rate of change of the temperature of the resistive element 410 is performed, but the control of the fan 310 is not performed.

[0076] The various operations described in this article can be implemented on a computer system. Figure 8 A block diagram of a representative computing system is shown, which includes one or more processors 504 and computer memory 502 capable of implementing this disclosure. The computing system may be implemented as, for example, a consumer device such as a smartphone, other mobile phone, tablet computer, wearable computing device (e.g., smartwatch, glasses, head-mounted display), desktop computer, laptop computer, or implemented using distributed computing devices. In some embodiments, control unit 510 is the computing system. In other embodiments, the computing system is a part or subsystem of control unit 510. In some embodiments, the computing system may include conventional computer components such as one or more processors 504, storage devices or computer memory 502, network interfaces, user input devices, and user output devices 516.

[0077] A network interface coupled to or otherwise communicating with a computer system can provide connectivity to a wide area network (e.g., the Internet), and the WAN interface of a remote server system can also be connected to that wide area network. The network interface may include a wired interface (e.g., Ethernet) and / or a wireless interface implementing various RF data communication standards, such as Wi-Fi, Bluetooth, UWB, or cellular data network standards (e.g., 3G, 4G, 5G, 60GHz, LTE, etc.).

[0078] User input devices may include any device (or devices) through which a user can provide signals to a computing system; the computing system may interpret these signals as indications of specific user requests or information. User input devices may include any or all of the following: keyboard, touchpad, touchscreen, mouse or other pointing device, scroll wheel, click wheel, dial, button, switch, keypad, microphone, sensor (e.g., motion sensor, eye-tracking sensor, etc.).

[0079] User output devices (e.g., display 516) can include any device through which a computing system provides information to a user. For example, display 516 can include a display for showing images generated by or transmitted to a computing system (e.g., control unit 510). The display can incorporate various image generation technologies (e.g., liquid crystal displays (LCDs), light-emitting diodes (LEDs) (including organic light-emitting diodes (OLEDs)), projection systems, cathode ray tubes (CRTs), etc.) and supporting electronics (e.g., digital-to-analog converters or analog-to-digital converters, signal processors, etc.). Devices that act as both input and output devices (such as touchscreens) can be used. Output device 516 can be provided as a supplement to or replacement for the display. Examples include indicator lights, speakers, haptic "display" devices, printers, etc.

[0080] Some specific implementations include electronic components (such as microprocessors, storage devices, and memories) that store computer program instructions in a computer-readable storage medium (e.g., a non-transitory computer-readable medium). Many of the features described in this specification can be implemented as processes, which are specified as a set of program instructions encoded on a computer-readable storage medium. When these program instructions are executed by one or more processors, they cause the processor to perform various operations indicated in the program instructions. Examples of program instructions or computer code include machine code (such as machine code generated by a compiler) and files that contain higher-level code executed by a computer, electronic component, or microprocessor using an interpreter. With appropriate programming, a processor can provide a variety of functionalities to a computing system, including any of the functionalities described herein as being performed by a server or client, or other functionalities associated with message management services.

[0081] It should be understood that the description of the computing system provided herein is illustrative, and variations and modifications to the configuration or specific implementation of the computer system are possible. Computer systems used in conjunction with this disclosure may have other capabilities not specifically described herein. Furthermore, although a computing system is described with reference to specific blocks, it should be understood that these blocks are defined for descriptive convenience and are not intended to imply a specific physical arrangement of the constituent parts. For example, different blocks may be located in the same facility, on the same server rack, on the same motherboard, or on the same circuit. Moreover, blocks do not necessarily correspond to physically different components. For example, blocks can be configured to perform various operations by programming the processor or providing appropriate control circuitry, and various blocks may or may not be reconfigurable depending on how the initial configuration is obtained. Specific implementations of this disclosure can be implemented in various devices, including electronic devices implemented using any combination of circuitry and software.

[0082] Unless otherwise specified, as used herein with respect to numerical ranges, the terms “approximately,” “about,” “basically,” and similar terms generally mean + / - 10% of the disclosed value. As used herein with respect to structural features (e.g., describing shape, size, orientation, direction, relative position, etc.), the terms “approximately,” “about,” “basically,” and similar terms are intended to cover minor structural variations that may occur, for example, during manufacturing or assembly, and are intended to have a broad meaning consistent with common usage accepted by one of ordinary skill in the art to which the subject matter of this invention pertains. Therefore, these terms should be interpreted as indicating that non-substantial or insignificant modifications or alterations to the described and claimed subject matter are considered to be within the scope of this disclosure as set forth in the appended claims.

[0083] As used herein, the term “coupling” and its variations mean that two components are directly or indirectly connected to each other. Such a connection can be static (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such a connection can be achieved by: two components being directly coupled to each other; two components being coupled to each other using a single intermediate component and any additional intermediate component; or two components being coupled to each other using an intermediate component that is integral with one of the two components to form a single whole. If “coupling” or its variations are modified by an additional term (e.g., direct coupling), the general definition of “coupling” provided above is modified by the colloquial meaning of the additional term (e.g., “direct coupling” means the connection of two components without any single intermediate component), resulting in a narrower definition than the general definition of “coupling” provided above. Such coupling can be mechanical, electrical, or fluid.

[0084] References to the location of elements herein (e.g., “top,” “bottom,” “above,” “below”) are used only to describe the orientation of the various elements in the accompanying drawings. It should be noted that, according to other embodiments, the orientation of the various elements may differ, and such variations are intended to be covered by this disclosure.

[0085] Hardware and data processing components for implementing the various processes, operations, exemplary logic, logic blocks, modules, and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed using a general-purpose single-chip or multi-chip processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some embodiments, specific processes and methods may be executed by dedicated circuitry specific to a given function. Memory (e.g., memory, memory cell, storage device) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage devices) for storing data and / or computer code for performing or facilitating the various processes, layers, and modules described herein. The memory may be or include volatile or non-volatile memory, and may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein. According to an exemplary embodiment, the memory is communicatively connected to a processor via processing circuitry and includes computer code for (e.g., by the processing circuitry or the processor) performing one or more of the processes described herein.

[0086] This disclosure contemplates methods, systems, and program products for implementing various operations on any machine-readable medium. Embodiments of this disclosure can be implemented using existing computer processors, or by a dedicated computer processor for a suitable system, combined for this or another purpose, or by a hardwired system. Embodiments within the scope of this disclosure include program products comprising machine-readable media for carrying or storing machine-executable instructions or data structures thereon. Such machine-readable media can be any available medium accessible by a general-purpose computer, a special-purpose computer, or other machine with a processor. By way of example, such machine-readable media may include RAM, ROM, EPROM, EEPROM, or other optical disc storage devices, magnetic disk storage devices, or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and accessible by a general-purpose or special-purpose computer or other machine with a processor. Combinations of the foregoing are also included within the scope of computer-readable media. Machine-executable instructions include, for example, instructions and data that cause a general-purpose computer, a special-purpose computer, or a special-purpose processing machine to perform a function or a set of functions.

[0087] Although the accompanying drawings and descriptions may illustrate a particular order of method steps, the order of such steps may differ from the order depicted and described unless otherwise specified above. Furthermore, unless otherwise specified above, two or more steps may be performed concurrently or partially concurrently. Such variations may depend on, for example, the chosen software and hardware system and the designer's choices. All such variations are within the scope of this disclosure. Similarly, software implementations of the described methods can be accomplished using standard programming techniques with rule-based logic and other logic to implement various connection steps, processing steps, comparison steps, and decision steps.

[0088] It is important to note that the constructions and arrangements of the various embodiments are merely illustrative. Additionally, any element disclosed in one embodiment may be used in conjunction with or together with any other embodiment disclosed herein.

Claims

1. A system for controlling the speed of resistive braking, the system comprising: A resistor grid having a resistive element (410). A sensor (520) configured to sense conditions indicating the temperature of the resistive element (410); The processing circuitry includes a memory (502) communicatively coupled to one or more processors (504), the memory (502) storing instructions that, when executed by the one or more processors (504), cause the processing circuitry to perform the following operations: When resistive braking is applied to the electric drive (112) machine (100), the speed of the electric drive (112) machine (100) is determined; When the resistive braking is applied to the electric drive (112) machine (100), the temperature of the resistive element (410) of the resistive grid is determined; The maximum resistance braking speed is calculated in response to the temperature satisfying a temperature threshold; and The maximum resistance braking speed is applied to the speed controller of the electric drive (112) machine (100) to prevent the electric drive (112) machine (100) from exceeding the maximum resistance braking speed.

2. The system according to claim 1, wherein the sensor (520) is a temperature sensor (520) configured to directly sense the temperature of the resistive element (410).

3. The system according to claim 1 or claim 2, wherein the condition includes the body insulator temperature.

4. The system of claim 3, wherein the condition includes the body insulator temperature, and wherein the processing circuitry is configured to estimate the insulator surface temperature based on the body insulator temperature.

5. The system according to any one of claims 1 to 4, wherein the temperature threshold is a predefined temperature below the maximum operating temperature of the resistive gate.

6. The system of claim 5, wherein the processing circuit is further configured to: Determine the rate of change of the temperature of the resistive element (410); and In response to the temperature of the resistive element (410) reaching the predefined temperature, the fan (310) is controlled to manage the rate of temperature change, thereby preventing the resistive element (410) from exceeding the maximum operating temperature of the resistive gate.

7. The system according to any one of claims 1 to 6, wherein the processing circuitry is further configured to receive data indicating the thermal quality of the resistive gate.

8. The system of claim 7, wherein the processing circuit is further configured to calculate the maximum resistive braking speed based on the temperature of the resistive element (410), the rate of change of the temperature of the resistive element (410), the thermal mass of the resistive grid, and the speed of the electric drive (112) machine (100) when resistive braking is applied to the electric drive (112) machine (100).

9. A method (600) for controlling the speed of resistive braking, the method (600) comprising: When resistive braking is applied to the electrically driven (112) machine (100), the speed of the electrically driven (112) machine (100) is determined by one or more processors (504); When the resistive braking is applied to the electric drive (112) machine (100), the temperature of the resistive element (410) of the resistive grid is determined by the one or more processors (504); In response to the temperature satisfying a temperature threshold, the maximum resistance braking speed is calculated by the one or more processors (504); and The maximum resistive braking speed is applied to the speed controller of the electric drive (112) machine (100) by the one or more processors (504) to prevent the electric drive (112) machine (100) from exceeding the maximum resistive braking speed.

10. The method (600) of claim 9, the method further comprising: The one or more processors (504) receive data indicating the temperature of the resistive element (410).

11. The method (600) of claim 10, wherein the temperature of the resistive element (410) is an insulator surface temperature, the method (600) further comprising: The insulator surface temperature is calculated by the one or more processors (504) based on the data indicating the temperature of the resistive element (410).

12. The method (600) of any of claims 9 to 11, the method further comprising: The temperature threshold is received by the one or more processors (504); and The temperature threshold is a predefined temperature below the maximum operating temperature of the resistive gate.

13. The method (600) according to claim 12, further comprising: The rate of change of the temperature of the resistive element (410) is determined by the one or more processors (504); as well as In response to the temperature of the resistive element (410) reaching the predefined temperature, the one or more processors (504) control the fan (310) to manage the rate of temperature change, thereby preventing the resistive element (410) from exceeding the maximum operating temperature of the resistive gate.

14. The method (600) according to any one of claims 9 to 13, the method further comprising: The one or more processors (504) receive data indicating the thermal quality of the resistive gate.

15. The method (600) according to claim 14, wherein the maximum resistive braking speed is calculated by the one or more processors (504) based on the temperature of the resistive element (410), the rate of change of the temperature of the resistive element (410), the thermal mass of the resistive grid, and the speed of the electric drive (112) machine (100) when resistive braking is applied to the electric drive (112) machine (100).

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