ELECTRICAL SYSTEM
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- GM GLOBAL TECHNOLOGY OPERATIONS LLC
- Filing Date
- 2023-10-05
- Publication Date
- 2026-07-23
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
INTRODUCTION
[0001] Electrified drive systems of motor vehicles and other mobile electrical systems include a electrical system configured to power one or more electric motors to drive a For example, an electric traction motor can be connected to the wheels of an electric vehicle connected, with the generated output torque being directed to the wheels to drive the electric vehicle on the For this purpose, a high-voltage bus of the electric vehicle is equipped with a rechargeable Energy storage system (´´RESS´´), the main component of which is a traction battery pack with a capacity The number and configuration of electrochemical battery cells is suitable for the application. The connection between Battery pack and motor is connected via an intermediate inverter module when the electrical Traction motor is configured as a multi-phase / AC machine.
[0002] Mobile and stationary high-voltage electric drive systems often have a separate Low-voltage bus for supplying numerous auxiliary devices. The terms ´´low voltage´´ and ´´Auxiliary voltage´´ includes voltage levels of approximately 12-50 volts (V) or less. Examples of auxiliary devices are internal and external lights, radios, screens and dashboard displays. Such devices are controlled via the Low voltage bus, with a DC-DC converter (DC-DC), e.g. an auxiliary power module, between the high-voltage and low-voltage bus. Since the voltage capacity of the high-voltage bus exceeds the nominal values of the auxiliary voltage of 12-50 V, the auxiliary power module is used to To isolate the high voltage side of the electrical system from the low voltage side. DESCRIPTION
[0003] An electrical system having a plurality of power converters, each having an input in electrical connection to a power source and an output in electrical connection with a load is presented here. A controller is configured to provide an output power request for the plurality of power converters The controller can then select at least one power converter from the plurality of power converters, to determine the output power requirement based on a power conversion efficiency of each of the plurality the power converters and an operating life of each of the plurality of power converters, and the instruct at least one power converter to generate power to meet the output power requirement.
[0004] Another aspect of the disclosure may be a system in which the efficiency of the power conversion each of the plurality of power converters includes an efficiency corresponding to an output power at or below the requested output power.
[0005] Another aspect of the disclosure may be a system in which the controller is configured to selects at least one power converter based on efficiency that results in the lowest power loss for which at least one power converter is required to meet the output power requirement.
[0006] Another aspect of the disclosure may be a system in which the controller controls the at least one Power converter based on the power conversion efficiency of the at least one power converter by comparing the power conversion efficiency with a percentage of the remaining usable Lifespan of at least one power converter scaled.
[0007] Another aspect of the disclosure may be a system in which the controller controls the at least one Power converters based on the remaining useful life of at least one power converter which is close to a maximum designed useful life of the at least one power converter.
[0008] Another aspect of the disclosure may be a system in which the at least one power converter at least two power converters configured to meet the output power requirement provide.
[0009] Another aspect of the disclosure may be a system in which the controller controls the at least one power converter based on the operating lifetime of each of the plurality of power converters by selecting the minimum selects a power converter with a remaining useful life.
[0010] Another aspect of the disclosure may be a system in which the remaining useful life is determined by a remaining period of time is defined in which the at least one power converter has a non-zero can generate output power.
[0011] Another aspect of the disclosure may be a system in which the remaining useful life is determined by the total remaining energy throughput that the at least one power converter can generate.
[0012] Another aspect of the disclosure may be a system in which the controller controls the at least one power converters based on the operating lifetime of each of the plurality of power converters by the at least one power converter based on a remaining useful life and the Replacement costs of at least one power converter.
[0013] Another aspect of the disclosure may be a system in which the controller controls at least one of the Power converters based on operating lifetime using a lookup table, a continuous function or a discrete function.
[0014] Another aspect of the disclosure may be a system in which the controller controls the at least one power converters based on the operating lifetime of each of the plurality of power converters by Reduces the total number of power converters in operation at any given time.
[0015] Another aspect of the disclosure may be a system in which the controller controls the at least one Power converters based on a cost hysteresis for switching between the power converters of the variety of power converters.
[0016] Another aspect of the disclosure may be a system in which the plurality of power converters Auxiliary power modules are configured to perform DC-DC power conversion.
[0017] Another aspect of the disclosure may be a system in which the plurality of current transformers are on-board Charging modules are configured to perform AC-to-DC power conversion.
[0018] Another aspect of the disclosure may be a system in which the at least one power converter comprises at least two power converters and the control is configured to control the amount of output power between the at least two power converters to meet the output power requirement.
[0019] Herein, a method for operating an electrical system with a plurality of power converters The method includes receiving an output power request for the plurality of power converters and selecting at least one power converter of the plurality of power converters to Output power requirement based on a power conversion efficiency of each of the plurality of Power converters and an operating lifetime of each of the multiple power converters. In addition, the method comprises instructing the at least one power converter to generate power to to meet output power requirements.
[0020] As disclosed herein, a vehicle system includes a traction motor, a traction battery connected to the traction motor in connection, and a plurality of power converters, each having an input in electrical connection with a power source and an output in electrical connection with a load. The system also includes a controller, configured to receive an output power request for the plurality of power converters and at least one power converter of the plurality of power converters to select the output power requirement to based on a power conversion efficiency of each of the plurality of power converters and a operating life of each of the multiple power converters. In addition, the controller is configured to that they have the min instructs at least one power converter to generate power to meet the output power requirement.
[0021] The above features and advantages, as well as other features and associated advantages of this disclosure are derived from the following detailed description of illustrative examples and modes for carrying out the This disclosure is readily apparent when taken in conjunction with the accompanying drawings and the accompanying claims. Furthermore, this disclosure expressly excludes combinations and Subcombinations of the elements and features shown above and below. BRIEF DESCRIPTION OF THE CHARACTERS Fig. 1 shows an example of an electrical system used to charge a high voltage battery pack wherein the high voltage battery pack is configured to supply power to a Low voltage bus supplies. Fig. 2 shows an example graph of output power (kW) versus efficiency (η) for several exemplary power converters. Fig. 3 is a diagram showing exemplary power outputs for power converters of the electrical system of Fig. 1 shows that have efficiencies as in Fig. 2 and according to a first set of parameters to meet optimized for a given output power requirement. Fig. 4 is a diagram showing the example power outputs for the power converters of the electrical system of Fig. 1 with the efficiencies shown in Fig. 2, which according to a second set of parameters for Optimized to meet the given output power requirement. Fig. 5 shows a method of operating the electrical system of Fig. 1 with a plurality of power converters.
[0022] The attached figures are not necessarily to scale and represent a somewhat simplified Representation of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, positions and shapes. Details associated with such features are determined in part by the intended application and environment. DETAILED DESCRIPTION
[0023] In the drawings, like reference numerals refer to like or similar components in the various figures. Fig. 1 shows an electrical system 12, e.g., an electrified drive system of a Motor vehicle 40 having a vehicle body 41 defining a vehicle interior 42. The motor vehicle 40 of Fig. 1 may also include a front trunk 46 or other compartment that allows the user access to a Charging socket REC. The motor vehicle 40 also includes wheels 43 for movement on roads. The wheels 43 can be driven / powered by the electrical system 12 or can be non-driven / free-running, as in Described in more detail below.
[0024] The electrical system 12 includes separate high-voltage and low-voltage buses. The high-voltage bus 20-H is in electrical connection with a high-voltage battery pack 13, e.g. a traction battery, and the Low voltage bus 20-L is in electrical connection with an auxiliary battery (B) 30. At least two or more AUX On-board charging modules (OBCMs) 22-1, 22-2 and 22-N contain inputs that can be connected to the charging socket REC as Current transformer to convert an AC power source from a charging station 50 into DC power at a socket to charge the battery pack 13. At least two or more auxiliary power modules (APMs) 21-1, 21-2, 21-N separate the high voltage bus 20-H from the low voltage bus 20-L with inputs connected to the High voltage bus 20-H and outputs connected to low voltage bus 20-L to charge the auxiliary battery 30 and operate vehicle accessories such as seat heating, electric windows or Navigation systems. The OBCMs 22 and APMs 21 are both connected to an electronic Control 28 in electrical system 12.
[0025] The electronic controller 28 may include a computer and / or processor and may include software, hardware, Memory, algorithms, connections, etc. for managing and controlling the operation of the motor vehicle 40. As Such a procedure can be described below and generally shown in Fig. 5 is provided, be embodied as a program or algorithm that can be partially operated on the controller 28. It should be appreciated that the controller 28 may comprise a device capable of receiving data from the Analyze sensors, compare data, make the necessary decisions to ensure the operation of the motor vehicle 40 and to perform the necessary tasks to ensure the operation of the motor vehicle 40 steer.
[0026] The controller 28 may be implemented as one or more digital computers or host machines, each one or more processors, a read-only memory (ROM), a random access memory (RAM), an electrically programmable read-only memory (EPROM), optical drives, magnetic drives, etc., a High-speed clock generators, analog-to-digital (A / D) circuits, digital-to-analog (D / A) circuits and input / Output (I / O) circuits, I / O devices and communication interfaces as well as signal conditioning and The computer-readable memory may be a non-transferable / tangible medium involved in the provision of data or computer-readable instructions. The memory may be non-volatile or volatile. Non-volatile media include, for example, optical or magnetic Hard disks and other permanent storage devices. An example of volatile media is dynamic random access memory (DRAM), which can represent main memory. Other examples of memory are flexible disks, hard disks, Magnetic tapes or other magnetic media, CD-ROMs, DVDs and / or other optical media as well as other possible Storage devices such as flash memory.
[0027] The controller 28 includes a tangible, non-transferable memory in which computer-executable Instructions, including one or more algorithms, for regulating the operation of the motor vehicle 40 The algorithm(s) concerned may include, in particular, an algorithm used to Optimization of the energy consumption of the motor vehicle 40 is configured.
[0028] In the example shown, features and functions of the power converters, such as the auxiliary power modules 21-1, 21- 2, 21-N or the on-board charging modules 22-1, 22-2, 22-N of Fig. 1, partially or completely into the structure of the electrical System 12. In addition, this teaching applies to a wide range of mobile and stationary Electrical system variants 12, including but not limited to electrified drive systems of Aircraft, ships, rail vehicles, agricultural equipment, transport equipment and other mobile Platforms on land, water or in the air as well as power plants, lifting equipment, conveyor systems and the like. The descriptions contained herein of the specific vehicle usage scenario shown in Fig. 1 are therefore not restrictive and only illustrate one possible implementation.
[0029] As for the representative electrical system 12 of Fig. 1, the electrical system 12 is characterized by its separate high-voltage and low-voltage buses, designated ´´20-H´´ and ´´20-L´´ respectively. In embodiments where the electrical system 12 is part of the motor vehicle 40, e.g., in an electric vehicle, which is available as a battery-powered electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle. range, the term ´´high voltage´´ can refer to battery voltage capabilities of about 300 volts (V) or more. Such voltages are suitable for generating drive torques for vehicle drive functions and to supply various high-voltage accessories on board the motor vehicle 40. The term ´´Low voltage´´ refers to auxiliary voltage levels of typically 12-50 V. Low voltage conductor (not shown) connect the low voltage bus 20-L to one or more low voltage accessories on On board the motor vehicle 40, including but not limited to lighting, radio equipment, infotainment screens, Sensors etc.
[0030] In the exemplary embodiment of Fig. 1, the battery pack 13 is connected via a series of high-voltage contactors 15 selectively connected to and disconnected from a load. The applied load in the configuration shown includes an intermediate circuit capacitor (C1), an inverter module (´´inverter´´) 16 with a plurality of Semiconductor switches 17, which are connected to an electric traction motor ('M') 18. As is known in the art, Inverters such as the inverter 16 shown in Fig. 1 use several semiconductor switches 17 as fast responsive ON / OFF switching devices, e.g., insulated gate bipolar transistors (IGBTs), metal oxide semiconductor Field effect transistors (MOSFETs), thyristors, etc. In a typical three-phase configuration of the electrical drive motor 18, the semiconductor switches 17 are switched on or off at predetermined switching intervals in order to AC waveform to the electric traction motor 18.
[0031] The electric drive motor 18 shown in Fig. 1 is connected to a rotatable output element 19, for example a motor shaft and a connected gearbox (not shown). In the drive modes, the inverter 16 controlled by pulse width modulation (PWM) or other suitable switching control technology to to excite the phase windings of the electric traction motor 18. As shown, the electric Traction motor 18 is a multi-phase AC motor, in this case a three-phase machine. The rotation of the Output element 19 finally transmits a torque (To) to a coupled load, including one or several wheels 43 of the motor vehicle 40. During the discharge / drive modes, the electrical energy stored in the electrochemical battery cells (not shown) of the high-voltage battery pack 13, for driving one or more wheels 43. Other embodiments of the motor vehicle 40 may be more or less Use impellers 43. In addition, some of the impellers 43 may be non-driven / free-running, e.g., in Rear-wheel drive or front-wheel drive configurations, or the wheels 43 may be driven / powered, e.g. B. in an all-wheel drive or four-wheel drive configuration, without restriction.
[0032] The electrical system 12 of Fig. 1 may also include additional components for supplying power to various Systems or functions on board the motor vehicle 40. For example, the battery pack 13, as shown, connected to the APMs 21-1, 21-2, 21-N. As such, the APMs 21-1, 21-2, 21-N are capable of generating a DC voltage of High voltage bus 20-H, e.g. 300 V or more, as mentioned above, to a typical auxiliary voltage level of 12-50 V for the low-voltage bus 20-L. The auxiliary battery 30, e.g. a 12V / 48V lead-acid or lithium Auxiliary battery, can be electrically connected to the APMs 21-1, 21-2, 21-N, whereby the internal switching operation of the APMs ensures that the auxiliary battery 30 remains charged, ie that the voltage of the auxiliary battery (V ) is approximately 12-50V. AUX
[0033] In order to determine the output power requirements received from the controller 28 for the electrical system 12 of the Motor vehicle 40, several power converters of a certain type, such as APMs or OBCMs, For example, if the output power requirement is low-voltage DC power, more than one of the APMs 21-1, 21-2 or 21-N may be required at any given time to Output power requirement for the low voltage bus 20-L. Likewise, with a Output power requirement for high voltage direct current more than one of the OBCMs 22-1, 22-2 or 22-N to a required at a specific time to meet the output power requirement for charging the battery pack 13.
[0034] A feature of this disclosure is the improvement of the power conversion efficiency of a electrical system when the power conversion is carried out using one or more power converters, such as OBCMs or APMs. The power converters can have the same maximum rated power and the same efficiency or have different maximum power ratings and efficiencies. This disclosure also includes the possibility of extending the service life of the electrical system 12 by selectively operating different combinations of power converters at a given time. This will extend the electrical system operating costs and the maintenance costs for the electrical system 12 required maintenance intervals. This disclosure achieves the above-mentioned features by selecting of at least one of the power converters based on the efficiency and lifetime of the Power converters to meet the output power requirement for different types of power converters in electrical to meet System 12.
[0035] In one example, the above features are achieved by minimizing a cost equation based on of the efficiency (η) and the lifetime of the power converters. Equation (1) shows an example of a Cost equation that can be minimized to increase the efficiency and lifetime of power converters in electrical system 12. ∑i=1N(Output Poweri*(1Efficiencyi-1)+F2i(Usable Life Remaining of PCi, Output of Pwr PCi)+f3i(Output Pwr of PCi))
[0036] The above example equation (1) indicates real or artificial costs in the form of watts for the operation of one or several power converters PC at a certain output power, which is the sum of the requested i Output power for the APMs or OBCMs. The real costs are calculated based on the actual Power loss calculated by the operation of a specific power converter PC i at a given output power based on its efficiency, and the artificial costs are determined by quantifying the effects of operating one or more power converters at a given Time calculated on the service life of the electrical system 12.
[0037] The first line of equation (1) calculates the cost in watts for operating one of the power converters at a specific output power, which either alone or together with other power converters, Output power requirement for the electrical system 12. Fig. 2 shows that the efficiencies (η) of the Power converters PC-1, PC-2, PC-3 to PC-N depending on the specific output power generated by the power converter For example, with an output power of less than 400 W, the PC-1 power converter less efficient than the power converter PC-2. Conversely, the power converter PC-1 is more efficient than the Power converter PC-2 if the output power is between 400 W and 1000 W.
[0038] Equation (1) uses the efficiency values shown in Fig. 2 to calculate the costs for the Power converter at a given output power. For example, Fig. 2 shows an efficiency of approximately 0.90 or 90% at 800 W for PC-1 and about 0.85 or 85% at 800 W for PC-2. This results in efficiency costs of 88.9 W for the operation of the power converter PC-1 at 800 W and costs of 141.2 W for the operation of the PC-2 power converter at 800 W. Based on these operating costs at an output power of 800 W, The controller 28 therefore prefers the power converter PC-1 to the power converter PC-2, since PC-1 at 800 W compared to to PC-2 has lower costs. Since the controller 28 in this disclosure controls the conversion and the load in the electrical System 12 can be individually controlled, the controller 28 can select the power converter(s) with the highest efficiency to minimize the power losses associated with power conversion by optimizing the system This is optimized. The controller 28 can also apply a calibration factor K to the first line of equation (1) 1 to vary the weighting of efficiency in its selection.
[0039] A feature of the controller 28 is the ability to individually control power converters with a specific output power to minimize the power consumed by an energy source, such as the battery pack 13 for the APMs 21 or the charging station 50 for the OBCMs 22. Since the controller 28 can provide a supervisory control, which specifies a current / power level for each power converter in the electrical system 12 such that a maximum number of power converters is kept in their optimal power conversion efficiency range, minimises the electrical system, the total energy losses due to conversion inefficiencies. The advantages of the control unit 28, which performs a monitoring function as described here, the available range of the motor vehicle 40 increase by directing more energy to the drive by reducing losses during power conversion become.
[0040] In addition, the controller 28 may limit the peak output power of the power converter PC. i In particular, the controller 28 may determine the peak power based on the remaining useful life of the Limit power converter PCs when the remaining useful life of the power converter PC is close to the maximum ii The usable lifespan of the power converter PC can be reduced by the i Total operating hours or total energy throughput can be defined.
[0041] In another example, the controller 28 may bias the electrical system 12 so that less than the Total number of power converters N is used by modifying the first line of equation (1) so that the Sum is formed over M power converters instead of N power converters. The controller 28 influences the electrical system 12 in such a way that less than the total number of power converters N is used by M limited to an integer greater than 0 and less than or equal to N. The controller 28 can also set the value of M on the Based on the overall age of the electrical system and output power requirements.
[0042] The function f in equation (1) creates artificial costs in watts associated with the operation of a given 2i power converter PC, based on a remaining lifetime of the given power converter i PC . The following equation (2) illustrates an example equation for quantifying the lifetime for the i Function f in equation (1). f2i=Xi*K2*Hrs of Life Utilized PCiMax Designed Life PCi 2i
[0043] Equation (2) quantifies the lifetime of the power converter PC in terms of lifetime hours required for the i Power converter PC used over a maximum designed service life for the power converter PC in hours ii In equation (2), X is a function of the output power of the power converter PC, where X is equal to 1 when iii the power converter PC has a non-zero output power, and X is zero if the power converter PC has a iii has zero output power.
[0044] In addition, K is a calibration factor that approximates the cost of using the given power converter PC 2 i the end of the maximum intended service life (e.g. operating hours). The calibration factor K is in watts 2 to obtain the function f in watts. Additionally, in one example, a value of K can be a single 2i 2 constant value for the power converter PC. i
[0045] In a further non-limiting example, K is a unique constant K for a particular 2 i Power converter PC . The value K can provide other information about the lifetime of the given power converter PC iii such as the relative costs of the power converters PC in the electrical system 12. A value of K could ii For example, the replacement costs (e.g., component and installation costs) for the power converter PC. Therefore i a power converter with higher replacement costs would have a calibration factor K that is greater than i a calibration factor K for a power converter with lower replacement costs to measure the electrical x System 12 to use the power converter with lower replacement costs. Controller 28 can also determine the values for the calibration factors using a lookup table with predefined values for power converter, or the controller 28 can provide a unique calibration factor for a power converter based on inputs regarding the replacement costs associated with replacing this power converter.
[0046] The controller 28 uses the function f to control the electrical system 12 so that individual current transformers in 2i a system with multiple current transformers approaching the end of a specified service life for a certain current transformers. By avoiding the use of power transformers, approaching the end of their predetermined operating life, the power conversion becomes more even over the several power converters in the electrical system 12 to extend the operating life of the electrical system 12 in Motor vehicle 40 to be extended.
[0047] In another example, the function f may be calculated based on the energy throughput for the power converter- 2i PC should be calculated according to equation (3) instead of based on hours using equation (2). Equation (3) i quantifies the lifetime of the power converter PC based on the total amount of energy throughput of the i Power converter PCs over a maximum designed operating lifetime of the power converter’s energy throughput i PCs . In an example, the terms X and K for equation (3) are calculated in the same way as above with respect ii2 described in equation (2). In another example, X could be equal to the PC's output power in watts, where ii K is a unitless constant. f2i=Xi*K2*Total Energy Throughput PCiMax Designed Energy Throughput PCi 2
[0048] While the disclosure uses example equations (2) and (3) for calculating the function f in equation (1) 2i a value for the function f could be taken from the controller 28 from a lookup table, a continuous 2i function or a discrete function.
[0049] In another non-limiting example, the controller 28 may determine the efficiency-based Combine or scale the calculation from the first line of equation (1) with the lifetime function f. 2i The following equation (4) illustrates an example of the implementation of this approach. ∑i=1N(Output Poweri*f2i( ULR of PCi, OP of PCi)*(1Efficiencyi-1))
[0050] The above equation (4) scales the calculation of the efficiency of the power converter PC by multiplying i the efficiency value taken from Fig. 2 with the value that represents the remaining predetermined lifetime for the power converter PC from equations (2) or (3). This approach results in the control 28 i from the use of power converters with a high efficiency and a low predetermined remaining lifetime for the use of a power converter with a lower efficiency and a longer predetermined remaining lifetime. A feature of this approach is to create a balanced use of power converters in the electrical system 12.
[0051] The function f in equation (1) generates the costs associated with the simultaneous operation of several power converters 3i and their impact on the lifetime of the entire power converter system in the electrical System 12. The following equation (5) illustrates an example function for quantifying the lifetime for the function f in equation (1). f3i=K3*Xi 3i
[0052] In equation (5), X is a function of the output power of the power converter PC , where X is equal to 1 when the iii Power converter PC has a non-zero output power, and X is zero if the power converter PC has a iii output power of zero. The calibration factor K in equation (5) also indicates the cost of the simultaneous 3 Operation of multiple power converters. The simultaneous operation of multiple power converters results in the Overall system of a specific power converter type, such as APMs or OBCMs, its system-specified The calibration factor K is given in power units of watts to 3 to obtain common units with the rest of equation (1).
[0053] A feature of the implementation of the function f by the controller 28 is the management of the lifetime of N 3i Power converters of a particular type as opposed to managing lifetime based on individual Power converter with the function f . The function f also causes the controller 28 to calculate the total number of 2i 3i power converters located in the system, since the calibration factor K is proportional to the total number of power converters with a 3 output power not equal to zero, as described above.
[0054] The function f manages the overall lifetime of the power converter system by calculating the cost of 3i simultaneous operation of more than one power converter. Based on this function, the Control 28 the electrical system 12 so that at a given time fewer power converters are operated This will determine the total number of operating hours of a particular power converter type in the electrical system 12, which increases the service life and prevents premature failure of a single power converter in a electrical system with multiple power converters.
[0055] In another example, the costs associated with f could be defined more broadly, with the costs being based on the 3i Based on a sum of the values X for N power converters, the control could be i 28 use a lookup table to determine a calibrated price for a possible value for the sum of the values X i for N power converters. In addition, the controller 28 could apply a function to the function f, e.g. 3i B. K multiplied by a square of the sum of the values X for N power converters to control 28 from the 3 i Selection of multiple power converters.
[0056] The controller 28 can also provide rapid switching between the states of the power converter at simultaneously meeting the output power requirement by applying a cost hysteresis, such as by the following equation (6): Minimum Costt-1-Minimum Costt>CostHysteresis
[0057] For an electrical system with N power converters of a certain type, the above equation (1) could be every 100 ms. The above equation (6) identifies the optimized costs from equation (1) in conjunction with a current time step as minimum cost and the optimized costs associated with the previous time step t are considered as Minimum Cost . Equation (6) also assumes that the output power requirement of the current t-1 time step and the previous time step are the same.
[0058] With these assumptions, a cost hysteresis Cost can be defined as a calibratable value to determine the Hysteresis To balance the efficiency and lifetime of the power converter with system stability. Using equation (6) the controller 28 can select the power converter load, which is determined by Mini mum Cost . Otherwise, the controller 28 can select the power converter utilization determined by Minimum Cost and t t-1 set Minimum Cost = Minimum Cost . t t-1
[0059] Figures 3 and 4 show example implementations of the controller 28 for implementing equation (1) for a electrical system 12 with two power converters and different output power requirements. The Equation (7) below illustrates an example implementation of equation (1) with two power converters. K 1*(Output Power1*(1&eegr;1-1)+Output Power2*(1&eegr;2-1))+K2*(X1*Hrs of Life Utilized PC1Max Designed Life PC1+X2*H rs of Life Utilized PC2Max Designed Life PC2)+(X1+X2)*K3
[0060] In the example shown in Fig. 3, the power converter PC-1 has a maximum output power of 1000 W and has reached 10% of its useful life. The PC-2 power converter has a maximum output power of 1500 W and has reached 50% of its useful life. The value for K is one, and the values for K and K 1 2 3 are zero kW. The efficiencies of the power converters PC-1 and PC-2 at the given output powers are from Fig. 2. Since the values of K and K in this example are zero kW, the controller 28 selects the most efficient 2 3 Power distribution across both power converters to generate the output power requirement, with the Sum of the output power of the power converters PC-1 and PC-2 equals the requested output power at the OPR management is.
[0061] Fig. 4 illustrates an example in which the controller 28 tends to select a power converter that has exhausted a larger percentage of its maximum service life. This preload behavior is determined by the calibration factor K, which is 999 kW. The value for K was compared to the example in Fig. 3 2 2 As shown in Fig. 4, this change causes the controller 28 to switch the power converter PC-1 on for a power requirement up to 1 kW, although the PC-2 power converter has a higher efficiency for Power requirements up to 400 W.
[0062] Fig. 5 shows an example of a method 100 according to this disclosure for operating an electrical system with a plurality of power converters. The method 100 includes receiving an output power request for the plurality of power converters (block 102). In one example, the signal received from the controller 28 provides Output power requirement a monitoring control that each power converter 21, 22 in the electrical system 12 sets a current / power level in a way that keeps the power converters in their optimal Power conversion efficiency range.
[0063] The controller 28 may then select at least one power converter from the plurality of power converters, to meet the output power requirement (block 104). The controller 28 supports the selection of the power converter on the power conversion efficiency of the multiple power converters at a given output power and an operating lifetime of the multiple power converters. The above equation (1) is an example of how the Control 28 the selection of at least one power converter on the efficiency and the service life of the multiple power converters. If the controller 28 bases its selection on the efficiency of the power conversion of the at least one power converter, the efficiency may be an efficiency of the at least one power converter at or below the requested output power.
[0064] Once the controller 28 has selected the at least one power converter, the controller 28 assigns the at least one power converter that provides the output power required to meet the output power requirement (Block 106). If more than one power converter is used to meet the output power requirement the output power of each power converter may differ to ensure the efficiency as to maximize as described above.
[0065] Accordingly, this disclosure provides an approach to operating an electrical system 12 that Improve the efficiency of the power converters and ensure a balanced use of the lifetime of each of the power converters to maximize the overall life of the electrical system 12. With the electrical System 12 installed in the motor vehicle 40, this will increase the range of a vehicle by providing more Energy can be used for propulsion than with of energy conversion, while at the same time ensuring the longevity of the electrical system’s ability to Energy conversion is maximized.
[0066] The detailed description and the drawings or illustrations are supporting and descriptive of the present teaching, but the scope of the present teaching is defined exclusively by the claims. While some of the best modes and other embodiments for carrying out the present teachings are described in detail There are various alternative designs and embodiments for carrying out the present teachings in defined in the appended claims.
Claims
1. An electrical system comprising: a plurality of power converters, each having an input in electrical connection with a power source and a Have an output in electrical connection with a load; and a controller configured to: Receiving an output power request for the plurality of power converters; Selecting at least one power converter from the plurality of power converters to fulfill the Output power requirement based on a power conversion efficiency of each of the plurality of power converters and an operating lifetime of each of the plurality of power converters; and Instructing the at least one power converter to generate power to meet the output power requirement.
2. Electrical system according to claim 1, wherein the power conversion efficiency of each of the plurality of Power converter includes an efficiency that corresponds to an output power at or below the Output power requirement.
3. Electrical system according to claim 2, wherein the controller is configured to control the at least one Selects power converters based on the efficiency that results in the least power loss for the at least one power converter required to meet the output power requirement.
4. Electrical system according to claim 1, wherein the controller controls the at least one power converter based on the efficiency of the power conversion of the at least one power converter by selecting the efficiency the power conversion with a percentage of the remaining useful life of at least one Power converter scaled.
5. Electrical system according to claim 1, wherein the controller controls the at least one power converter based on the remaining useful life of the at least one power converter that is close to a maximum designed useful life of at least one power converter.
6. Electrical system according to claim 1, wherein the at least one power converter comprises at least two power converters configured to provide the output power requirement.
7. Electrical system according to claim 1, wherein the controller controls the at least one power converter based on the operating life of each of the plurality of power converters by selecting the at least one power converter with a remaining useful life.
8. Electrical system according to claim 7, wherein the remaining useful life is determined by a remaining period of time is defined in which the at least one power converter can produce an output power other than zero.
9. Electrical system according to claim 7, wherein the remaining useful life is determined by the total remaining Energy throughput is defined that the at least one power converter can generate.
10. Electrical system according to claim 7, wherein the controller controls the at least one power converter based on the operating life of each of the multiple power converters by selecting the at least one power converter based on a remaining useful life and the Replacement costs of at least one power converter.