SAFETY-COMPLIANT CATALYTIC CONVERTER HEATING AFTERTREATMENT SYSTEM

Abstract

A power conversion device comprising a main circuit board having a first surface, a second surface, and a thermal conductor core disposed between the first surface and the second surface. A first subordinate circuit is mounted on the main circuit board. A first plurality of power switches is mounted on the first subordinate circuit board. A second subordinate circuit is mounted on the main circuit board. A second plurality of power switches is mounted on the second subordinate circuit board. A first heat transfer circuit includes a first set of conductors thermally coupling the first plurality of power switches to the thermal conductor core. A second heat transfer circuit includes a second set of conductors thermally coupling the second plurality of power switches to the thermal conductor core.

Description

BACKGROUND

[0001] The present application relates to safety-compliant catalyst heating aftertreatment systems and related devices, methods, systems, and techniques. A number of proposals have been made for heating catalysts of aftertreatment systems for combustion systems. Existing approaches to aftertreatment catalyst heating suffer from a number of disadvantages, limitations, problems, and deficiencies, including those related to complexity, cost, reliability, and safety. There remains a significant need for the particular devices, methods, and systems disclosed herein. DISCLOSURE OF EMBODIMENTS

[0002] In order to clearly, concisely, and accurately describe embodiments of the present disclosure, the manner and method of making and using the same, and to enable the practice, manufacture, and use of the same, reference will now be made to specific embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It is to be understood, however, that no limitation upon the scope of the invention is thereby created, and that the invention, as set forth in the claims following this disclosure, is intended to include and protect such changes, modifications, and other applications of the embodiments as would occur to one skilled in the art having the benefit of this disclosure. DESCRIPTION OF THE INVENTION

[0003] Some embodiments include particular safety-compliant catalyst heating aftertreatment devices. Some embodiments include particular safety-compliant catalyst heating aftertreatment systems. Some embodiments include particular safety-compliant catalyst heating aftertreatment methods. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing certain aspects of an exemplary prime mover system. The Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6 are schematic representations of certain aspects of example electronic control system implementations. Fig. Figure 7 is a flowchart illustrating certain aspects of an example control process. DETAILED DESCRIPTION OF EMBODIMENTS

[0004] With reference to Fig. 1, an exemplary prime mover system 100 (also referred to herein as system 100) is illustrated that includes a prime mover in the form of an internal combustion engine (ICE) 102. The system 100 may be provided in a variety of forms, such as a vehicle or vehicle powertrain system (e.g., an on-road vehicle or vehicle powertrain system, or an off-road vehicle or vehicle powertrain system), a work machine or work machine powertrain system, a power unit or power unit powertrain system, or a hydraulic fracturing rig or hydraulic fracturing rig powertrain system, to name a few non-limiting examples. It should be understood that the system 100 may include a variety of other components as would occur to one of ordinary skill in the art with the benefit and appreciation of the present disclosure.Furthermore, while the engine 102 may be provided as the prime mover of the system 100 in the illustrated embodiment, other embodiments may include other types of prime movers, such as battery electric propulsion systems, hybrid internal combustion engine (ICE) and battery systems, a fuel cell electric propulsion system, or prime mover systems that include combinations of the foregoing and / or other types of prime mover systems as would occur to one of ordinary skill in the art having the benefit and knowledge of the present disclosure.

[0005] The system 100 includes an intake system 108 and an exhaust system 110. The engine 102 is in fluid communication with the intake system 108, through which charge air enters an intake manifold 104, and is also in fluid communication with the exhaust system 110, through which the exhaust gas resulting from combustion exits via an exhaust manifold 106. The engine 102 includes a bank of cylinders (e.g., cylinders 1 through 6) that form combustion chambers in which a charge stream mixture of fuel and air is combusted. The energy released by combustion drives the engine 102, for example, via pistons in the cylinders connected to a crankshaft. Intake valves control the intake of charge air into the cylinders, and exhaust valves control the exhaust of exhaust gases through the exhaust manifold 106 and ultimately to the atmosphere. The exhaust manifold 106 may be a single manifold or multiple exhaust manifolds.

[0006] The turbocharger 112 includes a compressor 114 configured to receive filtered intake air via an intake air throttle (IAT) 116 of the intake system 108 and operable to compress ambient air before the ambient air enters the intake manifold 104 of the engine 102 at elevated pressure. The air from the compressor 114 is pumped through the intake system 108, to the intake manifold 104, and into the cylinders of the engine 102, typically generating torque at the crankshaft. The IAT 116 is fluidly coupled to a charge air cooler (CAC) 120, which may cool the charge flow supplied to the intake manifold 104. The intake system 108 also includes a CAC bypass valve 122 that can be opened to direct some or all of the charge flow to bypass the CAC 120.By adjusting the bypass position of the CAC bypass valve 122, the temperature of the gas returned to the intake manifold 104 is progressively increased.

[0007] It is contemplated that the turbocharger 112 in the system 100 may be a variable geometry turbocharger (VGT) or a fixed geometry turbocharger. A variable geometry turbine allows for significant flexibility in the pressure ratio within the turbine. In diesel engines, for example, this flexibility may be used to improve low-speed torque, reduce turbocharger lag, and control exhaust gas recirculation flow. In one embodiment, the VGT 124 may be adjusted to increase engine load and thereby increase exhaust gas temperature. The system 100 also includes a turbine bypass valve 126 for bypassing the turbocharger 112. Since cooler ambient air is supplied to the turbocharger 112, opening the turbine bypass valve 126 may bypass the turbocharger 112 and maintain a higher intake air temperature at the intake manifold 104.

[0008] The exhaust system 110 includes an exhaust gas temperature sensor 128 for sensing the temperature of the gas exiting the exhaust manifold 106. The exhaust system 110 includes an exhaust gas recirculation (EGR) valve 129 that recirculates a portion of the exhaust gas from the exhaust manifold 106 back to the intake manifold 104. The exhaust system 110 includes an EGR cooler (EGR-C) 118 that cools the gas exiting the exhaust manifold 106 before it returns to the intake manifold 104. The exhaust system 110 may also include an EGR-C bypass valve 117 that can be opened to redirect some or all of the recirculated exhaust gas from the exhaust manifold 106 to bypass the EGR-C 118. By increasing the amount of gas bypassing the EGR-C 118, the temperature of the gas returning to the intake manifold 104 is increased. It should be understood that the intake system 108 and / or the exhaust system 110 may include other components not shown, such asadditional coolers, valves, bypasses, intake throttle valves, exhaust throttle valves and / or compressor bypass valves.

[0009] The system 100 includes an exhaust aftertreatment (AT) system 136, which includes a diesel oxidation catalyst (DOC) 138, a diesel particulate filter (DPF) 140, an aftertreatment heater (AT) 142, and a selective catalytic reduction (SCR) 144. In the exemplary embodiment, the AT heater 142 is optionally integrated within the AT system 136 to increase the temperature of the exhaust gas supplied to the SCR 144 within the AT system 136. It should be noted that the AT heater 142 may include one or more electrical heaters distributed at various locations on, within, or upstream of the SCR 144 or other catalyst elements of the AT system 136.

[0010] The system 100 includes an electronic control system (ECS) 130. In the illustrated embodiment, the ECS 130 includes an engine control unit (ECU) 132, an aftertreatment control unit (ACU) 133, a heater control unit (HCU) 134, and a power system control unit (PSCU) 135 operatively communicatively coupled via one or more data links 131, which may include one or more controller area networks (CANs) and / or other types of data links. The system 100 may include a variety of other control units and controllers as will occur to one of ordinary skill in the art with the benefit and appreciation of the present disclosure.

[0011] The ECU 132 is operatively communicatively coupled to and configured and operable to control the operation of and / or receipt of inputs from actuators, controllers, devices, sensors, and / or other components of the system 100, including, for example, a number of the previously mentioned features of the system 100.

[0012] The HCU 134 is operatively coupled to the AT heater 142 and is configured and operable to control the operation thereof and / or receive inputs therefrom. It should be noted that various communication hardware and protocols may be used for implementation, such as one or more Controller Area Networks (CAN) or other communication components.

[0013] The PSCU 135 is operatively communicatively coupled to an electrical power system of the system 100, such as a motor generator system, a battery system, or other types of electrical power system, and is configured and operable to control the operation thereof and / or receive inputs therefrom.

[0014] ECU 132, ACU 133, HCU 134, PSCU 135, and other components of ECS 130 may include one or more solid-state integrated circuit programmable controllers and one or more non-transitory storage media configured to store instructions executable by the one or more microcontrollers. For purposes of this application, the term "controller" also includes microcontrollers, microprocessors, application-specific integrated circuits (ASICs), other types of integrated circuit processors, and combinations thereof.

[0015] ECU 132, ACU 133, HCU 134, PSCU 135, and other components of ECS 130 may be implemented in any number of ways that combine or distribute the control function among one or more control units in various ways. ECS 130 may execute operational logic that defines various control, management, and / or regulation functions. This operational logic may be in the form of dedicated hardware, such as a hard-wired state machine, an analog computing engine, programming instructions, and / or any other form as would occur to one skilled in the art. ECS 130 may be provided as a single component or as a collection of operatively coupled components and may consist of digital circuitry, analog circuitry, or a hybrid combination of these two types.When the ECS 130 is implemented with multiple components, one or more components may be remotely located relative to the others in a distributed arrangement. The ECS 130 may include multiple processing units arranged to operate independently of one another, in a pipelined processing arrangement, in a parallel processing arrangement, or the like.It should further be noted that the ECS 130 and / or each of its components may include one or more signal conditioners, modulators, demodulators, arithmetic logic units (ALUs), central processing units (CPUs), limiters, oscillators, control clocks, amplifiers, signal conditioners, filters, format converters, communication ports, clamps, delay devices, memory devices, analog-to-digital (A / D) converters, digital-to-analog (D / A) converters, and / or other circuits or components that would occur to one of ordinary skill in the art to perform the desired communication.

[0016] ECU 132, ACU 133, HCU 134, PSCU 135, and other components of ECS 130 may include one or more non-transitory memory devices configured to store instructions in memory that can be read and executed by a controller to control operation of engine 102 as described herein. Certain control operations described herein include operations for determining one or more parameters. ECU 132, ACU 133, HCU 134, PSCU 135, and other components of ECS 130 may be configured to determine and may perform determination operations in various ways, such as calculating or computing a value, obtaining a value from a lookup table or using a lookup operation, receiving values ​​from a data link or network communication, receiving an electronic signal (e.g.,a voltage, frequency, current, or pulse width modulation (PWM) signal indicating the value, receiving a parameter indicating the value, reading the value from a memory location on a computer-readable medium, receiving the value as a runtime parameter, and / or receiving a value by which the interpreted parameter can be calculated, and / or referencing a default value that is interpreted as a parameter value.

[0017] With reference to the Fig. 2 and Fig. 3, certain aspects of an exemplary electronic control system (ECS) 230 are illustrated. In the illustrated example, the ECS 230 includes a first electronic control unit configured and provided as a heating control unit (HCU) 234. In the illustrated example, the ECS 230 also includes a second electronic control unit configured and provided as a functional safety control unit (FSCU) 232. In the illustrated example, the ECS 230 further includes a third electronic control unit configured and provided as a power system control unit (PSCU) 219.

[0018] The ECS 230 is an example of an electronic control system with at least one electronic control unit configured to meet a predetermined functional safety (FuSa) requirement and with at least one further electronic control unit configured not to meet the FuSa requirement. It should be noted that functional safety can be formally defined as the absence of a defined risk due to hazards caused by faulty behavior of electrical and / or electronic systems. Within the scope of this disclosure, several predetermined FuSa requirements are considered, including, for example, the Automotive Safety Integrity Level (ASIL) requirements of the ISO 26262 standard, namely ASIL A, ASIL B, ASIL C, and ASIL D.In addition, an electronic control unit may be configured not to meet a particular FuSa requirement because it only meets a lower FuSa requirement, e.g., a lower ASIL requirement, or because it does not meet a FuSa requirement, e.g., because it is configured according to the quality management (QM) level requirements of ISO 26262.

[0019] In the illustrated example, the FSCU 232 is configured to meet a predetermined FuSa requirement. In some embodiments, for example, the FSCU 232 may be configured to meet the FuSa requirements of ASIL C. In other embodiments, the FSCU 232 may be configured to meet other FuSa requirements, such as the requirements of a different ASIL level or other FuSa requirements according to other standards.

[0020] The HCU 234 is configured to not meet the specified FuSa requirements that the FSCU 232 is configured to meet. For example, in some embodiments, the HCU 234 may be configured to meet Quality Management (QM) requirements and not meet an ASIL level. In other embodiments, the HCU 234 may be configured to meet a lower FuSa requirement than the FSCU 232, e.g., a lower ASIL level than the FSCU 232 or a lower level of other FuSa requirements.

[0021] In some embodiments, the PSCU 219 may be configured to meet the predetermined FuSa requirements that the FSCU 232 is configured to meet, or to meet a higher FuSa requirement, e.g., a higher ASIL level. In some embodiments, the PSCU 219 may be configured not to meet the predetermined FuSa requirements that the FSCU 232 is configured to meet. For example, in some embodiments, the PSCU 219 may be configured to meet quality management (QM) requirements and not adhere to an ASIL level. In other embodiments, the PSCU 219 may be configured to meet a lower FuSa requirement than the FSCU 232, e.g., a lower ASIL level than the FSCU 232 or a lower level of other FuSa requirements.

[0022] In the illustrated example, the HCU 234 is configured and equipped with two output channels. A first output channel of the HCU 234 is configured to power the heater 242 using power from the power supply (PS) 220 and the power converter 236, which is operatively coupled to the power supply 220 and configured to receive electrical energy therefrom to selectively power the load 245 of the heater 242. A second output channel of the HCU 234 is configured to power the heating element 262 using power from the power supply 220 and the power converter 266, which is operatively coupled to the power supply 220 and configured to receive electrical energy therefrom to selectively power the load 265 of the heating element 262.

[0023] The PSCU 219 is configured and operable to control the operation of the power supply 220. The power supply 220 may be configured and provided in a variety of forms, such as electrical power systems including a battery-backed power source, an alternator- or generator-backed power source, a battery and alternator- or generator-backed power source, or other types of electrical power sources as will occur to one of ordinary skill in the art with the benefit and appreciation of the present disclosure. In some embodiments, the electrical power source may be configured and provided as a 48V DC power source.

[0024] It should be noted that the ECS 130 of the system 100 may be configured and provided in forms corresponding to the ECS 230 or variations thereof. In some of these forms, the HCU 134 may correspond to the HCU 234 and the heater 242 may correspond to the heater 142. In some of these forms, the FSCU 232 may correspond to the ECU 132. In some of these forms, the FSCU 232 may correspond to the ACU 133. In some of these forms, the FSCU 232 may correspond to another electronic control unit of the ECS 130. In some of these forms, the PSCU 219 may correspond to the PSCU 135.

[0025] The FSCU 232 is configured to send communications to and receive communications from the HCU 234 via one or more data links 210, which may be configured and provided, for example, as one or more Controller Area Networks (CAN) or one or more other types of data links. The FSCU 232 is also configured to supply electrical power to the HCU 234 via line 212 and the lock enable signal 211. The FSCU 232 is further configured to receive FuSa feedback 218 and FuSa feedback 268 from the HCU 234.

[0026] The FSCU 232 supplies power to the HCU 234 via line 212 and the high-side driver (HSD) 206 from the power supply 205. In the illustrated embodiment, the power supply 205 is provided separately from the power supply 220 and is configured to provide electrical power at a lower voltage than the power supply 220. In some embodiments, the power supply 205 may comprise, for example, a 12 V or 24 V electrical power supply. In other embodiments, the power supply 205 may be configured to provide power at the same voltage as the power supply 220. In some of these embodiments, the power supply 205 and the power supply 220 may be combined or comprise the same power supply.HSD 206 includes one or more switches controlled by microcontroller 207 to selectively turn on a supply of electrical power to HCU 234 and turn off the supply of electrical power to HCU 234 from power supply 205.

[0027] Microcontroller 207 is configured to receive FuSa feedback 218 and FuSa feedback 268 from HCU 234 and evaluate or process FuSa feedback 218 and FuSa feedback 268 to evaluate one or more FuSa conditions and perform one or more FuSa operations. Several types of FuSa feedback, FuSa evaluations, and FuSa operations are contemplated.

[0028] In some embodiments, the FuSa feedback 218 may include one or more voltage values ​​that may be evaluated by the microcontroller 207 relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 242. Similarly, the FuSa feedback 268 may include one or more voltage values ​​that may be evaluated by the microcontroller 207 relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 262.

[0029] In some embodiments, the FuSa feedback 218 may consist of, or substantially consist of, one or more voltage values ​​that may be evaluated by the microcontroller 207 with respect to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 242. Similarly, the FuSa feedback 268 may consist of, or substantially consist of, one or more voltage values ​​that may be evaluated by the microcontroller 207 with respect to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 262.

[0030] In some embodiments, the FuSa feedback 218 may include one or more current values ​​that may be evaluated by the microcontroller 207 with respect to one or more current thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 242. Similarly, the FuSa feedback 268 may include one or more current values ​​that may be evaluated by the microcontroller 207 with respect to one or more current thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater 262.

[0031] In some embodiments, FuSa feedback 218 may include one or more temperature values ​​that may be evaluated by microcontroller 207 relative to one or more temperature thresholds to evaluate or identify an overtemperature condition of heater 242. Similarly, FuSa feedback 268 may include one or more temperature values ​​that may be evaluated by microcontroller 207 relative to one or more temperature thresholds to evaluate or identify an overtemperature condition of heater 262.

[0032] In some embodiments, the FuSa feedback 218 and the FuSa feedback 268 may include combinations of the aforementioned values ​​or other values ​​that may be evaluated by the microcontroller 207 with respect to corresponding thresholds.

[0033] Microcontroller 207 may be configured to perform a number of FuSa operations. In some embodiments, in response to evaluating or determining that FuSa feedback 218 indicates a fault condition of heater 242 and / or FuSa feedback 268 indicates a fault condition of heater 262, microcontroller 207 may set latch enable 211 to a logical false value and output it to latch circuitry 233 of HCU 234. In response, latch circuitry 233 may disable operation of HCU 234 to power load 245 of heater 242 and / or operation of HCU 234 to power load 265 of heater 262. Such deactivation may be accomplished, for example, by disabling the operation of the driver IC (driver integrated circuit) 235 and / or the power converter 236.

[0034] In some cases, the disabling performed in conjunction with the interlock may be channel-specific, such that a determination of FuSa feedback 218 indicating a fault condition of heater 242 results in only the operation of HCU 234 to power load 245 of heater 242 being disabled, and a determination of FuSa feedback 268 indicating a fault condition of heater 262 results in only the operation of HCU 234 to power load 265 of heater 262 being disabled. In some cases, such deactivation may be channel-unspecific or channel-independent, such that a determination of a FuSa feedback 218 indicating a fault condition of the heater 242 and / or a FuSa feedback 268 indicating a fault condition of the heater 262 results in the operation of the HCU 234 to power the load 245 of the heater 242 being disabled and the operation of the HCU 234 to power the load 265 of the heater 262 being disabled.

[0035] In some embodiments, in response to evaluating or determining that the FuSa feedback 218 indicates a fault condition of the heater 242 and / or the FuSa feedback 268 indicates a fault condition of the heater 262, the microcontroller 207 may control the HSD 206 to turn off or disable power to the HCU 234 via line 212, which in turn disables the operation of the microcontroller 231, the driver IC 235, the power converter 236, the driver IC 265, and the power converter 266.

[0036] In some embodiments, in response to an evaluation or determination that the FuSa feedback 218 indicates a fault condition of the heater 242 and / or the FuSa feedback 268 indicates a fault condition of the heater 262, the microcontroller 207 may send one or more commands over the data link 210 to the HCU 234 that may be executed by the microcontroller 231 to terminate or suspend operation of the driver IC 235 and the power converter 236 and / or the driver IC 265 and the power converter 266.

[0037] In some embodiments, microcontroller 207 may be configured to implement and execute combinations of any pair of the above FuSa operations, or a combination of all three of the above operations. Microcontroller 207 may also be configured to implement and execute other functional safety logic and operations, as further described elsewhere herein. It should further be noted that microcontroller 207 and / or microcontroller 231 may be configured to perform a variety of diagnostics in response to the FuSa feedback disclosed herein. Examples of such diagnostics include first-order diagnostics such as overvoltage fault, undervoltage fault, overcurrent fault, undercurrent fault, and overtemperature fault conditions.Other examples of such diagnostics include higher-order diagnoses such as diagnoses or prognostics that indicate current or future component malfunction or failure, which may be based on trends and other analyses performed on multiple instances of first-order diagnoses and various other diagnoses.

[0038] The FSCU 232 supplies electrical power to the microcontroller 231 via line 212. In some embodiments, the FSCU 232 may additionally supply electrical power via line 212 to the driver IC 235, the driver IC 265, and the latch circuits 233, as well as to other control circuits of the HCU 234. The FSCU 232 may also selectively provide enable signals and control signals to the microcontroller 231 via one or more data links 210 to selectively enable the operation of the microcontroller 231 and instruct it to control the driver IC 235 and the power converter 236 to power a load 245 of the heater 242, and to selectively enable the operation of the microcontroller 231 and instruct it to control the driver IC 265 and the power converter 266 to power a load 265 of the heater 262.Additional control signals may similarly be provided to cause the microcontroller 231 to enter or wake up from a sleep mode or to otherwise customize, control, or program the microcontroller 231.

[0039] One or more sensors 246 are configured to sense one or more operating characteristics of or associated with the load 245 of the heater 242. The one or more sensors 246 may include, for example, one or more voltage sensors configured to sense a voltage from or associated with the load 245, one or more current sensors configured to sense a current from or associated with the load 245, and / or one or more temperature sensors configured to sense a temperature from or associated with the load 245.

[0040] The output of the one or more sensors 246 may be provided as or used in determining FuSa feedback 218. In the illustrated example, the FuSa feedback 218 is also provided to the microcontroller 231, which may perform similar evaluations of the FuSa feedback 218 as the microcontroller 207, but without fulfilling the FuSa requirements of the FSCU 232. The FuSa feedback 218 is preferably provided to the FSCU 232 via a communication link capable of operating independently of other control circuitry of the HCU 234, for example, via one or more dedicated communication links.

[0041] One or more sensors 266 are configured to sense one or more operating characteristics of or associated with the load 265 of the heater 262. The one or more sensors 266 may include, for example, one or more voltage sensors configured to sense a voltage from or associated with the load 265, one or more current sensors configured to sense a current from or associated with the load 265, and / or one or more temperature sensors configured to sense a temperature from or associated with the load 265.

[0042] The output of the one or more sensors 256 may be provided as, or used in determining, FuSa feedback 268. In the illustrated example, the FuSa feedback 268 is also provided to the microcontroller 231, which may perform similar evaluations of the FuSa feedback 268 as the microcontroller 207, but without fulfilling the FuSa requirements of the FSCU 232. The FuSa feedback 268 is preferably provided to the FSCU 232 via a communication link capable of operating independently of other control circuitry of the HCU 234, for example, via one or more dedicated communication links, which may be the same as, or separate and different from, the one or more dedicated communication links over which the FuSa feedback 218 is transmitted.

[0043] In the illustrated embodiment, power converter 236 is configured and provided as a DC-to-DC power converter operatively coupled to and configured to receive direct current from power supply 220, which may provide this electrical energy from one or more electrical storage and / or generation systems. In some embodiments, power converter 236 may be configured and provided in the form of a buck converter, such as a nested buck converter. In other embodiments, power converter 236 may be configured and provided as another type of DC-to-DC converter. In other embodiments, power converter 236 may be configured and provided as an AC-to-DC power converter operatively coupled to and configured to receive alternating current from power supply 220.

[0044] The power converter 236 is further operatively coupled to the heater 242 and configured to drive it with energy from the power supply 220. The driver integrated circuit (IC) 234 is operatively coupled to the microcontroller 231 and configured to receive control commands therefrom and, in response to such control commands, to provide an output for driving the power converter 236. The driver IC 235 is further operatively coupled to the latch circuit 233 and configured to receive an enable command or signal therefrom.

[0045] In the illustrated embodiment, power converter 266 is configured and provided as a DC-to-DC power converter operatively coupled to and configured to receive direct current from power supply 220, which may provide electrical energy thereto from one or more electrical storage and / or generation systems. In some embodiments, power converter 266 may be configured and provided as a buck converter, such as a nested buck converter. In other embodiments, power converter 266 may be configured and provided as another type of DC-to-DC converter. In other embodiments, power converter 266 may be configured and provided as an AC-to-DC power converter operatively coupled to and configured to receive alternating current from power supply 220.

[0046] The power converter 266 is further operatively coupled to the heater 242 and configured to supply it with power from the power supply 220. The driver IC 265 is operatively coupled to the microcontroller 231 and configured to receive control commands therefrom and, in response to such control commands, to provide an output for driving the power converter 266. The driver IC is further operatively coupled to the latch circuit 233 and configured to receive an enable command or signal therefrom.

[0047] The latch circuit 233 is operatively coupled to and configured to receive a latch enable signal 211 from the FSCU 232. In the illustrated embodiment, the latch circuit 233 is also operatively coupled to another latch enable signal from the microcontroller 231 and an enable signal from a watchdog timer, which may be implemented in or in conjunction with the microcontroller 231 or another control circuit, HCU 234 or FSCU 232. The latch circuit 233 may be configured to disable the operation of the HCU if one or more of the inputs it receives have a logically false value.

[0048] The FSCU 232 is configured to send communications to the PSCU 219 and receive communications from the PSCU 219 via one or more data links 210. The FSCU 232 is further configured to send an enable signal 281 to the PSCU 219. The enable signal 281 may be sent and used to turn off the PSCU 219 and thereby indirectly disable the operation of the HCU 234 under certain conditions, such as when a fault, error, or malfunction prevents the FSCU 232 from successfully disabling or shutting down the HCU 234 in the event of a fault, error, or malfunction.In some embodiments, the FSCU 232 may be additionally configured to send electrical energy to the control circuitry of the PSCU 219 and / or receive additional FuSa feedback from the PSCU 219 to provide a substantially similar functional safety relationship and functionality of the FSCU 232 and the PSCU 219 as that of the FSCU 232 and the HCU 234.

[0049] The ones in connection with the Fig. The architectures and topologies described in Figures 1-3 may be used and deployed in a variety of forms. Some such forms may include a first power converter channel, such as the channel of power converter 236, configured to supply a first heater, such as heater 242, and a second power converter channel, such as the channel of power converter 266, configured to supply a second heater, such as heater 262. Some such forms may include different arrangements of multi-channel power converters and heater loads, including the following examples.

[0050] In Fig. 4, certain aspects of another example electronic control system (ECS) 430 are illustrated, providing another example arrangement of multi-channel power converters and heating loads. Several of the illustrated features of the ECS 430 generally correspond to those of the ECS 230, with the reference numerals of the ECS 430 increased by 200. It is also to be understood that the ECS 430 includes the other features described in connection with the ECS 230, which are described in Fig. 4 are not shown.

[0051] In the ECS 430, the HCU 434 includes a first output channel through which the power converter 436 selectively outputs power to power the heater 442, and a second output channel through which the power converter 466 selectively outputs power to power the heater 442. With this arrangement, the heater can be supplied with twice the rated power that would be provided by a single output channel. For example, two 5 kW channels can supply a 10 kW heating load, or two 10 kW channels can supply a 20 kW heater.

[0052] In relation to Fig. 5, certain aspects of another example of an electronic control system (ECS) 530 are illustrated, which provides another example arrangement of multi-channel power converters and heating loads. Several of the illustrated features of ECS 530 generally correspond to those of ECS 230, with the reference numerals of ECS 530 being incremented by 300. It should also be noted that ECS 530 includes the other features described in connection with ECS 230 and not in Fig. 5 are shown.

[0053] In the ECS 530, the HCU 534 includes a first output channel through which the power converter 536 selectively outputs power to power the heater 542, and a second output channel through which the power converter 536 selectively outputs power to power the heater 542. The ECS 530 further includes a switch 503 controllable by the HCU 534 and / or the FSCU 532 to selectively couple and decouple the second output channel to the heater 542. This arrangement allows the heater to be selectively supplied with a single-channel power rating and a double single-channel power rating. For example, two 5 kW channels can be selectively operated to supply a heating load of 5 kW or 10 kW, or two 10 kW channels can be selectively operated to supply a heating load of 10 kW or 20 kW.

[0054] With reference to Fig. 6, certain aspects of another example of an electronic control system (ECS) 630 are illustrated, which provides another example arrangement of multi-channel power converters and heating loads. A number of the illustrated features of ECS 430 generally correspond to those of ECS 230, with the reference numerals of ECS 430 incremented by 400. Furthermore, additional instances of such features are indicated with reference numerals incremented by 400, followed by an apostrophe or prime symbol. It should also be noted that ECS 630 includes the other features described in connection with ECS 230 and not in Fig. 6 are shown.

[0055] In ECS 630, HCU 634 includes a first output channel through which power converter 636 selectively outputs power to power heater 642, and a second output channel through which power converter 666 selectively outputs power to power heater 642. This arrangement allows the heater to be powered with twice the rated power that would be provided by a single channel output. For example, two 5 kW channels can power a 10 kW heater load, or two 10 kW channels can power a 20 kW heater. It is further contemplated that a switch similar to switch 503 of ECS 530 may be provided to provide associated functionality.

[0056] In ECS 630, HCU 634' includes a first output channel through which power converter 636' selectively outputs power to power heater 642', and a second output channel through which power converter 666' selectively outputs power to power heater 642. This arrangement allows the heater to be supplied with twice the rated power that would be provided by a single channel output. For example, two 5 kW channels can supply a 10 kW heater load, or two 10 kW channels can supply a 20 kW heater. It is further contemplated that a switch similar to switch 503 of ECS 530 may be provided to provide associated functionality.

[0057] With reference to Fig.7 is a flowchart illustrating certain aspects of an example control process 700 (also referred to herein as process 700). Process 700 is described in connection with a first ECU and a second ECU. The first ECU may correspond to the HCU 234, one of the other HCUs described herein, or another electronic control unit configured to fail to meet a predetermined functional safety (FuSa) requirement. The second ECU may correspond to the FSCU 232, one of the other FSCUs described herein, or another electronic control unit configured to meet the predetermined FuSa requirement.

[0058] Process 700 begins at startup operation 702 and proceeds to operation 704, where the second ECU enables operation of the first ECU, for example, by setting a logic value of a lock enable signal to true and / or by issuing an enable signal to the first ECU. From operation 704, process 700 proceeds to operation 706, where the second ECU sends a power-on command to the first ECU. From operation 706, process 700 proceeds to operation 708, where the first ECU turns on one or more output channels to power a load (e.g., a heater coil) of one or more heaters.

[0059] From operation 708, process 700 proceeds to operation 710, where the second ECU reads one or more FuSa feedback parameters that provide information indicative of the state of one or more corresponding output channels of the first ECU. In some embodiments, the one or more FuSa feedback parameters may include one or more voltage values ​​that may be evaluated relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater. In some embodiments, the one or more FuSa feedback parameters may consist of, or substantially consist of, one or more voltage values ​​that may be evaluated relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater.In some embodiments, the one or more FuSa feedback parameters may include one or more current values ​​that may be evaluated relative to one or more current thresholds to evaluate or identify an undercurrent and / or overcurrent condition of the heater. In some embodiments, the one or more FuSa feedback parameters may include one or more temperature values ​​that may be evaluated relative to one or more temperature thresholds to evaluate or identify an overtemperature condition of the heater. In some embodiments, the one or more FuSa feedback parameters may include combinations of the above values ​​or other values ​​that may be related to corresponding thresholds.

[0060] From operation 710, process 700 proceeds to operation 712, where the second ECU evaluates the one or more FuSa feedbacks for one or more fault conditions. In some embodiments, evaluating the one or more FuSa feedback parameters may include evaluating one or more voltage values ​​relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition. In some embodiments, evaluating the one or more FuSa feedback parameters may consist of, or substantially consist of, evaluating one or more voltage values ​​relative to one or more voltage thresholds to evaluate or identify an undervoltage and / or overvoltage condition of the heater.In some embodiments, evaluating the one or more FuSa feedback parameters may include evaluating one or more current values ​​relative to one or more current thresholds to evaluate or identify an undercurrent and / or overcurrent condition of the heater. In some embodiments, evaluating the one or more FuSa feedback parameters may include evaluating one or more temperature values ​​relative to one or more temperature thresholds to evaluate or identify an overtemperature condition of the heater. In some embodiments, evaluating the one or more FuSa feedback parameters may include combinations of the foregoing evaluations or other evaluations relative to corresponding thresholds.

[0061] If condition 712 evaluates negatively, process 700 proceeds to operation 710. If condition 712 evaluates positively, process 700 proceeds to operation 714, where the second ECU sets an error value equal to true and disables operation of the first ECU, e.g., by setting a logic value of a lock enable signal to false, by turning off power to the first ECU, by instructing the first ECU not to operate, or by performing a combination of two or more of the foregoing operations or other operations.

[0062] From operation 714, process 700 proceeds to condition 716, which evaluates whether an error condition is true. If condition 716 evaluates negatively, process 700 continues with operation 714. If condition 716 evaluates positively, process 700 continues with condition 712.

[0063] As is apparent from this detailed description, several and various embodiments are provided in the present disclosure, including, without limitation, the following embodiments.

[0064] A first embodiment is a prime mover system comprising: an engine; an aftertreatment system configured to treat exhaust gases of the engine; an electrical power source; a heater configured to selectively heat the aftertreatment system;and an electronic control system comprising a first electronic control unit configured to selectively power the heater using power from the electrical power source, and a second electronic control unit configured to selectively enable and disable operation of the first electronic control unit to power the heater in response to feedback received from the first electronic control unit, wherein the second electronic control unit is configured to meet predetermined functional safety requirements and the first electronic control unit is configured not to meet the predetermined functional safety requirements;

[0065] A second embodiment includes the features of the first embodiment, wherein the first electronic control unit includes a power converter configured to convert energy from the electrical power source to power the heater, and a latch circuit configured to selectively enable and disable the power converter in response to a signal received from the second electronic control unit.

[0066] A third embodiment includes the features of the first embodiment, wherein the second electronic control unit is configured to provide electrical energy from a second electrical energy source to a control circuit of the first electronic control unit, the second electrical energy source being independent of the electrical energy source.

[0067] A fourth embodiment includes the features of the third embodiment, wherein the second electronic control unit is configured to selectively shut off the supply of electrical power to the control circuitry of the first electronic control unit in response to the feedback.

[0068] A fifth embodiment includes the features of the first embodiment, wherein the feedback includes feedback indicating a voltage of the heater.

[0069] A sixth embodiment includes the features of the fifth embodiment, wherein the second electronic control unit is configured to evaluate the feedback and selectively disable operation of the first electronic control unit to power the heater in response to an evaluation of the received feedback indicating an overvoltage condition or an undervoltage condition of the heater.

[0070] A seventh embodiment includes the features of the first embodiment, wherein the first electronic control unit has a first power output channel and a second power output channel configured to selectively supply the heater.

[0071] An eighth embodiment includes the features of the first embodiment, wherein the electronic control system includes a third electronic control unit configured to selectively power the heater using power from the electrical power source, the second electronic control unit configured to selectively enable and disable operation of the third electronic control unit to power the second heater in response to second feedback received from the third electronic control unit, the third electronic control configured to fail to meet the predetermined functional safety requirements.

[0072] A ninth embodiment includes the features of the first embodiment, wherein the electronic control system includes a third electronic control unit configured to selectively power a second heater using power from the electrical power source, the second electronic control unit configured to selectively enable and disable operation of the third electronic control unit to power the second heater in response to second feedback received from the third electronic control unit, the third electronic control being configured to fail to meet the predetermined functional safety requirements.

[0073] A tenth embodiment is a method for controlling a prime mover system having an engine, an aftertreatment system configured to treat exhaust gases of the engine, an electrical power source and a heater configured to selectively heat the aftertreatment system, and an electronic control system, the method comprising: operating a first electronic control unit of the electronic control system to selectively power the heater using power from the electrical power source, providing feedback from the first electronic control unit to a second electronic control unit of the electronic control system, and operating the second electronic control unit to selectively enable and disable operation of the first electronic control unit to power the heater in response to the feedback,wherein the operation of the second electronic control unit meets predetermined functional safety requirements, and the operation of the first electronic control unit does not meet the predetermined functional safety requirements.,

[0074] An eleventh embodiment includes the features of the tenth embodiment, wherein operating a first electronic control unit of the electronic control system to selectively power the heater using power from the electrical power source comprises operating a power converter of the first electronic control unit to convert power from the electrical power source to power the heater and operating a latch circuit to selectively enable operation of the power converter in response to a signal received from the second electronic control unit.

[0075] A twelfth embodiment includes the features of the tenth embodiment and includes operating the second electronic control unit to provide electrical energy from a second electrical energy source to a control circuit of the first electronic control unit, wherein the second electrical energy source is independent of the first electrical energy source.

[0076] A thirteenth embodiment includes the features of the twelfth embodiment and includes operating the second electronic control unit to selectively shut off the provision of electrical power to the control circuit of the first electronic control unit in response to the feedback.

[0077] A fourteenth embodiment includes the features of the tenth embodiment, wherein the feedback comprises feedback indicating a voltage of the heater.

[0078] A fifteenth embodiment includes the features of the fourteenth embodiment and includes operating the second electronic control unit to evaluate the feedback and selectively disabling operation of the first electronic control unit to power the heater in response to an evaluation of the received feedback indicating an overvoltage condition or an undervoltage condition of the heater.

[0079] A sixteenth embodiment includes the features of the tenth embodiment, wherein operating a first electronic control unit of the electronic control system to selectively power the heater using power from the electrical power source comprises selectively powering the heater with a first power output channel and a second power output channel of the first electronic control unit.

[0080] A seventeenth embodiment includes the features of the tenth embodiment, comprising: operating a third electronic control unit of the electronic control system to selectively power the heater using energy from the electrical energy source; providing a second feedback signal from the third electronic control unit to the second electronic control unit; and operating the second electronic control unit to selectively enable and disable operation of the first electronic control unit to power the heater in response to the feedback signal; wherein operating the third electronic control unit does not meet the predetermined functional safety requirements.

[0081] An eighteenth embodiment includes the features of the tenth embodiment, comprising: operating a third electronic control unit of the electronic control system to selectively power a second heater using energy from the electrical energy source; providing a second feedback signal from the third electronic control unit to the second electronic control unit; and operating the second electronic control unit to selectively enable and disable operation of the first electronic control unit to power the second heater in response to the feedback signal; wherein operating the third electronic control unit does not meet the predetermined functional safety requirements.

[0082] A nineteenth embodiment is an apparatus for controlling a prime mover system including an engine, an aftertreatment system configured to treat exhaust gases of the engine, an electrical power source, and a heater configured to selectively heat the aftertreatment system, the apparatus comprising: an electronic control system comprising: a first electronic control unit configured to selectively power the heater using power from the electrical power source, and a second electronic control unit configured to selectively enable and disable operation of the first electronic control unit to power the heater in response to feedback received from the first electronic control unit, the second electronic control unit being configuredthat it meets predetermined functional safety requirements, and the first electronic control unit is configured so that it does not meet the predetermined functional safety requirements.

[0083] A twentieth embodiment includes the features of the nineteenth embodiment, wherein the first electronic control unit includes a power converter configured to convert energy from the electrical power source to power the heater, and a latch circuit configured to selectively enable and disable the power converter in response to a signal received from the second electronic control unit.

[0084] A twenty-first embodiment includes the features of the nineteenth embodiment, wherein the second electronic control unit is configured to provide electrical power from a second electrical power source to a control circuit of the first electronic control unit, the second electrical power source being independent of the first electrical power source.

[0085] A twenty-second embodiment includes the features of the twenty-first embodiment, wherein the second electronic control unit is configured to selectively shut off the supply of electrical power to the control circuitry of the first electronic control unit in response to the feedback.

[0086] It should be understood that terms such as “a non-transitory memory,” “a non-transitory storage medium,” and “a non-transitory storage device” refer to a variety of types of devices and storage media that may be configured to store information, such as data or instructions, that can be read or executed by a processor or other components of a computer system, and that these terms include and encompass a single or unitary device or medium storing such information, multiple devices or media on or between which corresponding portions of such information are stored, and multiple devices or media on or between which multiple copies of such information are stored.

[0087] It is to be understood that terms such as "determine", "determined", "determining" and the like, when used in connection with a control method or process, an electronic control system or controller, electronic controls, or components or operations of the foregoing, refer to a set of acts, configurations, devices, operations, and techniques, including but not limited to calculating or determining a parameter or value, obtaining a parameter or value from a lookup table or using a lookup operation, obtaining parameters or values ​​from a data link or network communication, obtaining an electronic signal (e.g.a voltage, frequency, current, or pulse width modulation (PWM) signal) indicative of the parameter or value, receiving the output of a sensor indicative of the parameter or value, receiving other outputs or inputs indicative of the parameter or value, reading the parameter or value from a memory location on a computer-readable medium, receiving the parameter or value as a runtime parameter, and / or by receiving a parameter or value by which the interpreted parameter can be calculated, and / or by referring to a default value that is interpreted as the parameter value.

[0088] Although exemplary embodiments of the disclosure have been shown and described in detail in the drawings and the foregoing description, they are to be considered as illustrative and not restrictive, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications which come within the spirit of the claimed inventions are intended to be protected. It should be understood that the use of words such as preferably, preferentially, preferentially, or more preferably in the above description indicates that the feature so described may be more desirable, but that it may not be necessary, and that embodiments not having that feature may be considered within the scope of the invention, the scope being defined by the following claims.When reading the claims, it should be noted that the use of words such as "a," "an," "at least one," or "at least a part" is not intended to limit the claim to only one subject matter unless the claim expressly states otherwise. When the phrase "at least a part" and / or "a part" is used, the subject matter may include part and / or all of the subject matter unless expressly stated otherwise.

Claims

[1] Drive machine system (100) comprising: an engine (102); an aftertreatment system (136) configured to treat the exhaust gases of the engine; an electrical energy source (220); a heater (142, 242) configured to selectively heat the aftertreatment system; and an electronic control system (130, 230) comprising a first electronic control unit (134, 234) configured to selectively power the heater using energy from the electrical energy source, and a second electronic control unit (132, 232) configured to selectively enable and disable operation of the first electronic control unit to power the heater in response to feedback received from the first electronic control unit (134, 234), wherein the second electronic control unit (132, 232) is configured to meet predetermined functional safety requirements and the first electronic control unit (234) is configured not to meet the predetermined functional safety requirements. [2] The prime mover system (100) of claim 1, wherein the first electronic control unit (234) includes a power converter (236) configured to convert energy from the electrical power source to power the heater (242), and a latch circuit (233) configured to selectively enable and disable the power converter in response to a signal received from the second electronic control unit. [3] The prime mover system (100) of claim 1 or 2, wherein the second electronic control unit (232) is configured to provide electrical energy from a second electrical energy source (205) to a control circuit of the first electronic control unit (234), the second electrical energy source being independent of the electrical energy source (220). [4] The prime mover system (100) of claim 3, wherein the second electronic control unit (232) is configured to selectively shut off the supply of electrical energy to the control circuit of the first electronic control unit (234) in response to the feedback. [5] The prime mover system (100) of any preceding claim, wherein the feedback includes feedback indicative of a heater voltage. [6] The prime mover system (100) of claim 5, wherein the second electronic control unit (232) is configured to evaluate the feedback and selectively disable operation of the first electronic control unit (234) to power the heater in response to an evaluation of the received feedback indicating an overvoltage condition or an undervoltage condition of the heater. [7] The prime mover system (100) of any preceding claim, wherein the first electronic control unit (234) includes a first power output channel and a second power output channel configured to selectively supply the heater. [8] The prime mover system (100) of any one of claims 1 to 7, wherein the electronic control system includes a third electronic control unit (219) configured to selectively power the heater using power from the electrical power source, the second electronic control unit (232) configured to selectively enable and disable operation of the third electronic control unit to power the second heater in response to second feedback received from the third electronic control unit, the third electronic control being configured to fail to meet the predetermined functional safety requirements. [9] The prime mover system (100) of any one of claims 1 to 7, wherein the electronic control system includes a third electronic control unit (219) configured to selectively power a second heater using power from the electrical power source, the second electronic control unit (232) configured to selectively enable and disable operation of the third electronic control unit to power the second heater in response to second feedback received from the third electronic control unit, the third electronic control being configured to fail to meet the predetermined functional safety requirements. [10] A method of controlling a prime mover system (100) comprising an engine (102), an aftertreatment system (136) configured to treat exhaust gases of the engine, an electrical energy source (220), and a heater (142, 242) configured to selectively heat the aftertreatment system, and an electronic control system (130, 230), the method comprising: Operating a first electronic control unit (134, 234) of the electronic control system to selectively power the heater using energy from the electrical energy source, Providing feedback from the first electronic control unit to a second electronic control unit (132, 232) of the electronic control system, and Operating the second electronic control unit (132, 232) to selectively enable and disable the operation of the first electronic control unit (134, 234) to supply the heater in response to the feedback, wherein the operation of the second electronic control unit (134, 234) satisfies predetermined functional safety requirements, and the operation of the first electronic control unit (132, 232) does not satisfy the predetermined functional safety requirements. [11] The method of claim 10, wherein operating a first electronic control unit (234) of the electronic control system to selectively power the heater using energy from the electrical energy source comprises operating a power converter (236) of the first electronic control unit to convert energy from the electrical energy source to power the heater and operating a latch circuit (233) to selectively enable operation of the power converter in response to a signal received from the second electronic control unit. [12] The method of claim 10 or 11, comprising operating the second electronic control unit (232) to provide electrical energy from a second electrical energy source (205) to a control circuit of the first electronic control unit (234), wherein the second electrical energy source is independent of the first electrical energy source (220). [13] The method of claim 12, comprising operating the second electronic control unit (232) to selectively shut off the provision of electrical power to the control circuit of the first electronic control unit (234) in response to the feedback. [14] The method of any one of claims 10 to 13, wherein the feedback comprises feedback indicating a voltage of the heater. [15] The method of claim 14, comprising operating the second electronic control unit (232) to evaluate the feedback and selectively disabling operation of the first electronic control unit (234) to power the heater in response to an evaluation of the received feedback indicating an overvoltage condition or an undervoltage condition of the heater. [16] The method of any one of claims 10 to 15, wherein operating a first electronic control unit (234) of the electronic control system to selectively power the heater using energy from the electrical energy source comprises selectively powering the heater with a first power output channel and a second power output channel of the first electronic control unit. [17] Method according to one of claims 10 to 16, comprising: Operating a third electronic control unit (219) of the electronic control system to selectively power the heater using energy from the electrical power source; Providing a second feedback from the third electronic control unit to the second electronic control unit (232); and Operating the second electronic control unit to selectively enable and disable operation of the first electronic control unit to power the heater in response to the feedback; wherein the operation of the third electronic control unit does not meet the predetermined functional safety requirements. [18] Method according to one of claims 10 to 16, comprising: Operating a third electronic control unit (219) of the electronic control system to selectively power a second heater using energy from the electrical energy source; Providing a second feedback from the third electronic control unit to the second electronic control unit (232); and Operating the second electronic control unit to selectively enable and disable operation of the first electronic control unit to power the second heater in response to the feedback; wherein the operation of the third electronic control unit does not meet the predetermined functional safety requirements. [19] An apparatus for controlling a prime mover system (100) including an engine (102), an aftertreatment system (136) configured to treat exhaust gases of the engine, an electrical energy source (220), and a heater (142, 242) configured to selectively heat the aftertreatment system, the apparatus comprising: an electronic control system (130, 230) comprising: a first electronic control unit (134, 234) configured to selectively power the heater using energy from the electrical power source, and a second electronic control unit (132, 232) configured to selectively enable and disable the operation of the first electronic control unit to power the heater in response to feedback received from the first electronic control unit (134, 234), wherein the second electronic control unit (132, 232) is configured to meet predetermined functional safety requirements and the first electronic control unit (234) is configured not to meet the predetermined functional safety requirements. [20] The apparatus of claim 19, wherein the first electronic control unit (234) includes a power converter (236) configured to convert energy from the electrical power source to power the heater (242), and a latch circuit (233) configured to selectively enable and disable the power converter in response to a signal received from the second electronic control unit. [21] The apparatus of claim 19 or 20, wherein the second electronic control unit (232) is configured to provide electrical energy from a second electrical energy source (205) to a control circuit of the first electronic control unit (234), the second electrical energy source being independent of the first electrical energy source (220). [22] The apparatus of claim 21, wherein the second electronic control unit (232) is configured to selectively shut off the supply of electrical energy to the control circuitry of the first electronic control unit (234) in response to the feedback.

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