Systems and methods of distributing propulsion load power drawn from high-energy and high-power batteries

Abstract

The present disclosure relates to systems and methods of distributing propulsion load power drawn from high-energy and high-power batteries. Specifically, a system and method of distributing load power drawn from a plurality of batteries for electric propulsion of a vehicle. The system includes: a high-energy battery and a high-power battery designed for optimal production of DC power during high specific energy propulsion and high specific power propulsion, respectively; and a battery health management system configured to monitor state of charge and state of health of the batteries and generate battery state signals. The system further includes a propulsion load configured to produce propulsion force using power converted from power generated by at least one of the batteries; and a system controller configured to distribute load power drawn from the high-energy battery and the high-power battery for use by the propulsion load according to a propulsion phase of the vehicle and the battery state.

Description

Technical Field

[0001] This disclosure generally relates to battery-dependent hybrid and all-electric systems for providing power to connected loads such as propulsion loads of aircraft or other vehicles. Background Technology

[0002] As used herein, the term "propulsion load" refers to an electric propeller that consumes (active) electricity. This is different from a power source such as a battery that generates electricity. As used herein, the term "load power" refers to the electricity drawn from the battery and consumed by the electric propeller. As used herein, in the context of a battery, the term "connected" means connecting the battery to supply load power, and the term "disconnected" means disconnecting the battery to stop supplying load power.

[0003] Some aircraft have electric propulsion systems (hereinafter referred to as "electric aircraft"). In such aircraft, electric motors convert electrical electricity into mechanical power to power the propulsion system. For example, an electric motor can rotate one or more propellers on the aircraft to provide thrust. Electric aircraft can take many forms. For example, an electric aircraft can be an aircraft, a rotorcraft, a helicopter, a quadcopter, an unmanned aerial vehicle, or some other suitable type of aircraft.

[0004] When an electric motor is used for propulsion in an aircraft or other vehicle, electrical energy is supplied by a power source. For example, this power source can be a DC power supply comprising a "battery" connected between positive and negative high-voltage direct-current (HVDC) buses. As used herein, in the context of DC, the term "high voltage" refers to a voltage greater than 270V. DC Any DC voltage. The battery supplies power to the electric motor, which is configured to convert electrical power into mechanical power for the propulsion system of the aircraft or other vehicle.

[0005] Some electric propulsion vehicles have a hybrid power architecture (e.g., hybrid-powered aircraft), in which at least two different types of power sources are connected in parallel to the propulsion load. The electrical energy sources typically have different electrical characteristics. For example, the electrical energy source could be a battery and a generator driven by an internal combustion engine or gas turbine.

[0006] One limiting factor for future hybrid and all-electric systems that rely on advanced battery technology is the battery's specific energy. (As used in this article, "specific energy" refers to the energy capacity of a battery per unit weight.) Several battery cell manufacturers are researching technologies that enable specific energy exceeding 350 Wh / kg, but these technologies tend to have performance limitations such as high specific power capabilities. (As used in this article, "specific power" refers to watt-level load capacity per unit weight.) Batteries are typically sized for both energy and power, resulting in overly large and bulky batteries. If power demand exceeds the capabilities of the cell technology, designers must either increase battery size to meet the requirements or use different cell technologies with better power capabilities but lower specific energy.

[0007] For future hybrid and all-electric systems that depend on advanced battery technology, lightweight, high-performance batteries are desired. Summary of the Invention

[0008] The subject matter disclosed below in considerable detail relates to a system and method for distributing load power drawn from a battery system comprising multiple batteries of different designs for the electric propulsion of a vehicle. The design of individual batteries is optimized to minimize overall battery weight while meeting the power requirements of different operating modes. According to one embodiment, the battery system includes a battery (hereinafter referred to as the "HE battery") designed to achieve optimal performance during high specific energy propulsion and a high-power battery (hereinafter referred to as the "HP battery") designed to achieve optimal performance during high specific power propulsion. The overall system also includes a system controller configured such that the battery system achieves optimal performance and reduced weight while avoiding oversizing the battery system to handle peak loads.

[0009] More specifically, the system controller is configured to distribute the load power drawn from the HE and HP batteries and then control multiple DC-AC converters to supply AC power to the corresponding AC-powered devices (e.g., electric propellers). In the case of a vehicle, the system controller is configured to adjust the load power distribution according to the changing power demand during the vehicle's propulsion. In at least some cases, the load power drawn by the device is distributed to the HE and HP batteries according to the vehicle's operating mode (e.g., the flight phase of the aircraft).

[0010] According to one implementation, the system controller is configured to determine the relationship between the amount of DC power to be provided by the HE battery and the amount of DC power to be provided by the HP battery in a specific operating mode. The system controller receives information indicating the system's power demand and then determines how to allocate the load power drawn from the HE and HP batteries to meet that demand. To make this determination, the system controller needs to know the status and health (e.g., state of charge, years of service life, impedance, capacity, temperature, etc.) of the HE and HP batteries. Each battery in the HE and HP batteries has a corresponding dedicated state of charge (SOC) and state of health (SOH) monitoring / management system (hereinafter referred to as the "SOC / SOH manager") associated with it, which is connected to the system controller. The SOC / SOH manager sends battery status signals to the system controller and receives command signals from the system controller. The corresponding load power drawn from the HE and HP batteries during various phases of the task is allocated by the system controller, which controls the corresponding DC voltage conversion system to receive high-voltage DC power from the HE and HP batteries. The resulting DC power can then be converted into AC power to power one or more AC-powered devices (e.g., AC motors).

[0011] According to one proposed implementation, the individual cells in the HE and HP batteries can be composed of corresponding battery packs. As used herein, the term "battery pack" refers to one or more battery modules wired in series, parallel, or a combination thereof, each battery module consisting of a large number of battery cells. For example, the HE battery can be a first battery pack managed by a first SOC / SOH manager, while the HP battery can be a second battery pack managed by a second SOC / SOH manager. The SOC / SOH manager can be a corresponding processor or computer, or a corresponding module hosted by a computer. In either case, an apparatus is provided for transmitting SOC and SOH data acquired by the SOC / SOH manager to a system controller. The system controller and the SOC / SOH manager can be a battery health management system equipped with other components, configured to perform various disconnection and protection functions in response to the occurrence of a fault in the battery pack (e.g., a short circuit).

[0012] Although various embodiments of systems and methods for the electric propulsion of a vehicle to distribute load power drawn from HE and HP batteries will be described in considerable detail below, one or more of these embodiments can be characterized by one or more of the following aspects.

[0013] One aspect of the subject matter disclosed in detail below is a system for distributing load power drawn from a battery system for the electric propulsion of a vehicle, the system comprising: a high-energy battery designed to optimally produce DC power during high-specific-energy propulsion; a high-energy battery health management system configured to monitor the state of charge and health of the high-energy battery and generate a first battery state signal representing the state of charge and health of the high-energy battery; and a high-power battery. The vehicle includes a high-power battery designed for optimal DC power production during high-power-density propulsion; a high-power battery health management system configured to monitor the state of charge and health of the high-power battery and generate a second battery status signal representing the state of charge and health of the high-power battery; a propulsion load configured to produce propulsion using power converted from electricity generated by at least one of the high-power battery and the high-power battery; and a system controller configured to receive the first battery status signal and the second battery status signal, and then allocate load power drawn from the high-power battery and the high-power battery for use by the propulsion load based on the propulsion phase of the vehicle and the states of the high-power battery and the high-power battery represented by the first battery status signal and the second battery status signal.

[0014] According to one embodiment of the system described immediately following the preceding paragraph, the vehicle is an aircraft, the propulsion phase is the flight phase, and the system controller is configured to: (1) during high-demand periods (such as the high-power phase of the aircraft, which includes takeoff, climb, and secondary climb)) allocate appropriate load power to be drawn from the high-energy battery and the high-power battery; and (2) during low-demand periods (such as the cruise phase of the aircraft, which includes cruise and hover) allocate a first load power to be drawn from the high-energy battery (without allocating any load power to the high-power battery) and a second load power to be drawn from the high-energy battery for charging the high-power battery.

[0015] Another aspect of the subject matter disclosed in detail below is a computer-implemented method for distributing load power drawn from a battery system for the electric propulsion of a vehicle. This battery system includes a high-energy battery designed for optimal production of DC power during high-specific-energy propulsion and a high-power battery designed for optimal production of DC power during high-specific-power propulsion. The method includes the following steps: (a) monitoring the state of charge and state of health of the high-energy battery; (b) generating a first battery state signal representing the state of charge and state of health of the high-energy battery; (c) monitoring the state of charge and state of health of the high-power battery; (d) generating a second battery state signal representing the state of charge and state of health of the high-power battery; and (e) distributing load power drawn from the high-energy battery and the high-power battery based on the propulsion phase of the vehicle and the states of the high-energy battery and the high-power battery as represented by the first and second battery state signals.

[0016] Another aspect of the subject matter disclosed below is a system for distributing load power drawn from a battery system for the electric propulsion of a vehicle. This system includes: a DC distribution bus; a first DC voltage conversion system connected to the DC distribution bus; a high-energy battery connected to the first DC voltage conversion system, the high-energy battery being designed for optimal DC power production during high-specific-energy propulsion; a high-energy battery health management system configured to monitor the state of charge and health of the high-energy battery and generate a first battery status signal representing the state of charge and health of the high-energy battery; a second DC voltage conversion system connected to the DC distribution bus; and a high-power battery connected to the second DC voltage conversion system, the high-power battery being... Designed for optimal DC power production during high-power-density propulsion; a high-power battery health management system configured to monitor the state of charge and health of the high-power battery and generate a second battery status signal representing the state of charge and health of the high-power battery; and a system controller configured to receive the first and second battery status signals and send commands to a first and a second DC voltage conversion system, which allocate load power drawn from the high-energy and high-power batteries based on the propulsion phase of the vehicle and the status of the high-energy and high-power batteries as represented by the first and second battery status signals. According to some embodiments, the system further includes: a first DC-AC converter connected to a DC distribution bus; a first propulsion load connected to receive AC power from the first DC-AC converter; a second DC-AC converter connected to the DC distribution bus; and a second propulsion load connected to receive AC power from the second DC-AC converter, wherein the system controller is further configured to send commands to the first DC-AC converter and the second DC-AC converter to control the amount and frequency of corresponding AC power supplied to the first propulsion load and the second propulsion load.

[0017] Other aspects of systems and methods for distributing load power drawn from HE and HP batteries to the electric propulsion of a vehicle are disclosed below. Attached Figure Description

[0018] The features, functions, and advantages discussed in the preceding chapters can be implemented independently in various embodiments or combined in other embodiments. Hereinafter, for the purpose of illustrating the above and other aspects, various embodiments are described with reference to the accompanying drawings. In the drawings, rectangles drawn with solid lines indicate enabled components, while rectangles drawn with dashed lines indicate disabled components.

[0019] Figure 1It is a block diagram that identifies the components of a typical aerospace electric propulsion system architecture with a single propeller.

[0020] Figure 2 This is a block diagram illustrating the architecture of a system designed to distribute load power drawn from a battery system according to one embodiment.

[0021] Figure 3 It is a block diagram identifying the components of a system that, according to one embodiment, distributes load power drawn from high-energy batteries and high-power batteries to the electric propulsion of an aircraft.

[0022] Figure 4 It is an instruction based on Figure 3 The flowchart depicts the proposed implementation of the system, showing the electrical flow during the takeoff or climb phase of aircraft flight.

[0023] Figure 5 It is an instruction based on Figure 3 The flowchart depicts the proposed implementation of the system and the power flow during the cruise phase of the aircraft's flight.

[0024] Figure 6 It is an instruction based on Figure 3 The flowchart depicts the proposed implementation of the system and the electrical flow during the descent / deceleration phase of the aircraft's flight.

[0025] Figure 7 It is an instruction in Figure 3 The flowchart depicts the power flow of the system operating in fault-tolerant mode.

[0026] Figure 8 It is an instruction in Figure 3 The flowchart depicts the power flow of the system when it is operating in ground charging mode.

[0027] The accompanying drawings are described below, in which similar elements in different drawings have the same reference numerals. Detailed Implementation

[0028] The following is a fairly detailed description of an exemplary implementation of a system and method for distributing load power drawn from HE and HP batteries for the electric propulsion of a vehicle. However, not all features of an actual implementation are described in this specification. Those skilled in the art will recognize that in developing any such implementation, numerous specific implementation decisions must be made to achieve the developer's specific objectives (such as compliance with system-related and business-related constraints), which will vary from one implementation to another. Furthermore, it should be appreciated that such development work can be complex and time-consuming, but is merely a routine task for those of ordinary skill in the art who will benefit from this disclosure.

[0029] For illustrative purposes, a system for distributing load power drawn from multiple batteries for the electric propulsion of an electric aircraft is described below. However, the technology presented herein is not limited to its application in aircraft, but can also be applied to the propulsion of other types of electric vehicles, such as automobiles, industrial trucks, and trains.

[0030] Figure 1 This is a block diagram illustrating the components of a typical aerospace electric propulsion system architecture with a single propeller. The propeller is partially formed by a motor controller 24, an AC motor 28, and a propeller 30. The motor controller 24 converts DC power to AC power, the AC motor 28 receives AC power from the motor controller, and the propeller 30 is driven to rotate by the AC motor 28. The propeller 30 includes an output shaft mechanically coupled to the AC motor 28. Figure 1 (not shown) propeller shaft Figure 1 (not shown) and multiple propeller blades ( Figure 1 (Not shown).

[0031] In some implementations, the motor controller 24 has three channels that supply AC current to corresponding groups of stator windings in the AC motor 28. Each channel of the motor controller 24 includes a corresponding inverter with a power switch. Figure 1 (not shown), and the corresponding inverter controller that controls the state of the power switch ( Figure 1 (Not shown) (these are collectively referred to herein as "inverter / controller"). Connect the inverter to the windings of AC motor 28 ( Figure 1 (Not shown). The operation of the inverter is controlled by an inverter controller, which communicates via switching signal lines (…). Figure 1 (Not shown) Sends switching control signals to the inverter and receives switching status signals from the inverter. The inverter converts DC power into multiphase AC power for the AC motor 28.

[0032] exist Figure 1 In the depicted system, the HVDC power source is battery 18. For example, battery 18 may include a large number of battery modules configured to form a battery pack. Figure 1 (Not shown). Each battery module is a parallel / series arrangement of individual cells. Each battery module can be monitored by an associated module monitoring unit (…). Figure 1 (Not shown) is monitored. Each module monitoring unit includes sensors for independently measuring the virtual cell voltage and individual cell temperature. The module monitoring unit also includes a balancing circuit.

[0033] Figure 1The described system also includes a DC voltage conversion system 20 configured to receive low-voltage DC power from battery 18 and convert it into high-voltage DC power. The DC voltage conversion system 20 includes a converter controller and a voltage converter (collectively referred to herein as "converter / controller"). The converter controller generates control signals based on a specific switching modulation algorithm (e.g., pulse width modulation, phase shift modulation, and interleaved modulation, or a combination of two or three of these). By controlling the voltage converter using one of the aforementioned specific modulation methods, the converter controller converts the input current at the input voltage into the output current at the output voltage, while simultaneously achieving specific electric performance requirements, such as improved efficiency, reduced current ripple, and minimized noise.

[0034] Figure 1 The system described also includes DC distribution bus 22 ( Figure 1 The DC distribution bus 22 is connected to receive high-voltage DC power from the DC voltage conversion system 20. The motor controller 24 also receives high-voltage DC power from the DC distribution bus 22.

[0035] Figure 1 The system described also includes a battery health management system 14. The operation of battery 18 is managed by the battery health management system 14. The monitoring units of each module incorporated into battery 18 transmit sensor data representing virtual cell voltage and individual cell temperature to the battery health management system 14. The battery health management system 14 can be configured to ensure redundancy protection, fail-safe operation, and selective shutdown of battery strings. The battery health management system 14 can also be configured to provide battery overcharge protection or prevent other events or combinations of events that could lead to battery thermal runaway. More specifically, the contactor ( Figure 1 The switching state (not shown) is controlled by the battery health management system 14 to disconnect in response to the detection of a fault condition (e.g., short circuit).

[0036] As in Figure 1 As seen in the image, the system also includes a system controller 12. The system controller 12 is interfaced with the battery health management system 14. The inverter controller of the motor controller 24... Figure 1 (Not shown) is communicatively connected to receive control signals from system controller 12 and send feedback signals to system controller 12. System controller 12 performs the supervisory and coordination role of all inverter controllers. System controller 12 also receives pilot thrust and pitch input from thrust control stick and pitch control stick. Figure 1(Not shown). The system controller 12 monitors and coordinates the operation of the inverter controller based on information from sensor and guide rod inputs.

[0037] replace Figure 1 The electric propulsion system described herein, featuring a single battery 18, proposes an improved electric propulsion system comprising integrated HE and HP batteries (e.g., a battery pack). This improved electric propulsion system is designed to minimize battery weight while meeting the power requirements of different operating modes of the electric propulsion system. The HE battery is designed for optimal DC power production during high-specific-energy propulsion; the HP battery is designed for optimal DC power production during high-specific-power propulsion. High-specific-energy propulsion is typically associated with relatively low power demand conditions, for which high-specific-energy batteries offer the advantage of low weight. HP batteries, with relatively low specific energy (~200 Wh / kg), allow discharge rates greater than 5C, while HE batteries, with relatively high specific energy (~400 Wh / kg), allow a 1C rate to maintain healthy battery operation. In describing the batteries, the discharge current is typically expressed relative to the C-rate to normalize it to battery capacity. The C-rate is a measure of the rate at which a battery discharges relative to its maximum capacity. Therefore, incorporating HP batteries is particularly beneficial during high-power demand modes (e.g., during takeoff and climb of the aircraft). HE and HP batteries are controlled separately but coordinated through the system controller. The battery design presented in this paper ensures the proper distribution of the appropriate load power drawn from the HE and HP batteries under load demand and system controller commands.

[0038] Figure 2 This is a block diagram illustrating the architecture of a system designed to distribute load power drawn from HE and HP batteries by the aircraft's propellers (not shown). Figure 2 The described system includes: an HE battery health management system 14a configured to monitor the state of charge and state of health of an HE battery and generate a first battery state signal 32a representing the state of charge and state of health of the HE battery; and an HP battery health management system 14b configured to monitor the state of charge and state of health of an HP battery and generate a second battery state signal 32b representing the state of charge and state of health of the HP battery.

[0039] Each battery health management system includes sensors for monitoring various characteristics of individual battery cells, such as cell voltage, cell current, and cell temperature. Voltage, current, and temperature sensors are connected to corresponding analog-to-digital converters (ADCs). These ADCs acquire battery data in analog form from the sensors, convert the data into digital output, and then send the digital output to a processor unit (e.g., a SOC / SOH manager). The processor unit can be a processor, microcontroller, multiple processors, a multi-core processor, and / or a microprocessor. The processor unit is configured to process the sensor data and derive battery performance information, such as the battery voltage, battery current, battery temperature, state of charge (SOC), and state of health (SOH) of each battery cell. At a given time, the battery has a maximum energy storage potential. This maximum energy storage potential can change over time. The state of charge (SOC) is the comparison between the amount of energy stored in the battery and the maximum amount of energy the battery can currently store. The state of health is determined by detecting, predicting, and isolating various anomalies, which may include, but are not limited to, capacity degradation, unusual temperature behavior, charge loss, changes in internal resistance, abnormal pressure, and dimensional changes. Health status is a comparison of the aforementioned parameters with their values ​​when the battery was new.

[0040] The system also includes a system controller 12, which is connected to the flight computer 10 and the HE battery health management system 14a and HP battery health management system 14b. The flight computer 10 receives mission inputs (such as destination, flight conditions, restricted airspace, fuel reserves, etc.) and then outputs flight data related to the propulsion control of the system controller 12. Figure 2 The arrow labeled "Flight Control Input" indicates that the flight data is transmitted to the system controller 12. The system controller 12 also receives a first battery status signal 32a and a second battery status signal 32b from the HE battery health management system 14a and the HP battery health management system 14b. The system controller 12 is configured to allocate load power drawn from the HE and HP batteries for use by the propulsion load, based on the aircraft's flight phase (represented by the flight control input) and the status of the HE and HP batteries (represented by the battery status signals). The system controller 12 allocates the drawn load power by sending control signals 34 to the corresponding DC voltage conversion systems.

[0041] Figure 3 This is a block diagram illustrating the components of a system, according to one embodiment, that distributes load power drawn from the battery system 11 to the DC power distribution bus 22 for the electric propulsion of a vehicle. The operation of the overall system is controlled by a system controller 12, which is communicatively connected to the various components of the battery system 11.

[0042] Battery system 11 includes an HE battery 18a and an HP battery 18b, which are connected in parallel to the DC distribution bus 22 to provide one-fault tolerance. The HE battery 18a is designed for optimal DC power production during high specific energy propulsion, and the HP battery 18b is designed for optimal DC power production during high specific power propulsion. Battery system 11 also includes a DC voltage converter / controller 20a of a DC voltage conversion system connected to the HE battery 18a and the DC distribution bus 22; and a second DC voltage conversion system of a DC voltage converter / controller 20b connected to the HP battery 18b and the DC distribution bus 22. Each DC voltage converter / controller sends feedback signals to and receives command signals from system controller 12, and executes specific charging or discharging control algorithms with appropriate current, voltage, and power levels. The batteries to which each converter / controller is connected provide a stable, compact, and narrow bandwidth for the DC bus voltage, allowing for lighter distribution, protection, and load equipment.

[0043] The battery system 11 further includes: an HE battery health management system including a first SOC / SOH manager 16a, the first SOC / SOH manager 16a being configured to monitor the state of charge and state of health of the HE battery 18a and generate battery status signals representing the state of charge and state of health of the HE battery 18a; and an HP battery health management system including a second SOC / SOH manager 16b, the second SOC / SOH manager 16b being configured to monitor the state of charge and state of health of the HP battery 18b and generate battery status signals representing the state of charge and state of health of the HP battery 18b. More specifically, the SOC / SOH managers 16a and 16b send battery status signals to the system controller 12 (described below) and receive command signals from the system controller 12.

[0044] System controller 12 is configured to process battery status signals received from SOC / SOH managers 16a and 16b, and then send commands to DC voltage converters / controllers 20a and 20b to allocate load power drawn from HE batteries 18a and 18b. System controller 12 is configured (e.g., programmed) to determine optimal load power allocation based at least on the aircraft's flight phase (represented by flight control inputs) and the status of HE and HP batteries 18b (represented by first and second battery status signals). Other data can also be factored into the load allocation calculation.

[0045] Figure 3The depicted system also includes a first inverter / controller 24a of a first motor controller and a second inverter / controller 24b of a second motor controller. Each inverter / controller is configured to perform DC-to-AC conversion at a required frequency that controls the shaft speed of the motor-propeller assembly of the propulsion load. Both motor controllers receive DC power from DC distribution bus 22. The first propulsion load is connected to receive AC power from the first inverter / controller 24a; the second propulsion load is connected to receive AC power from the second inverter / controller 24b. System controller 12 is also configured to send commands to the inverter controllers to control the magnitude and frequency of the AC power output. More specifically, each inverter / controller receives command signals from system controller 12 and sends feedback signals to system controller 12, and executes a specific DC-AC conversion algorithm to provide AC power of appropriate magnitude and frequency. The frequency of the AC power determines the speed of the motor shaft. The required propulsion speed is determined by system controller 12.

[0046] On the load side, Figure 3 The illustrated example system includes: a first propulsion load 26a connected to receive AC power from inverter / controller 24a; a second propulsion load 26b connected to receive AC power from inverter / controller 24b; a non-propulsion load 6 connected to receive DC power from DC distribution bus 22; and a charging station 8 also connected to DC distribution bus 22 for charging the battery in charging mode. The non-propulsion load 6 may be a composite load, which may include multiple individual loads. All loads are controlled by system controller 12.

[0047] The system controller 12 is configured to optimize load power distribution once a specific mission profile has been received. For example, a typical mission profile includes a cycle of operating modes (flight phases), such as taxiing, takeoff, climb, cruise, descent / deceleration, landing, taxiing, and reserve, where the reserve phase requires sufficient remaining battery energy for a second climb and a certain period of hovering before landing.

[0048] The power requirements during the cruise phase are significantly lower than those during takeoff or climb, typically less than half the power required during takeoff / climb. Other modes (such as descent, landing, and taxiing) require even less power. Therefore, the system controller 12 is configured to control the DC voltage converter / controller so that load power during cruise, descent, landing, and taxiing phases is drawn solely from the HE battery, or optimally distributed between the HE and HP batteries as needed.

[0049] Typically, two flight phases require the majority of the energy stored in the battery system: (1) the high-power phase, which includes takeoff, climb, and secondary climb; and (2) the cruise phase, which includes cruising and hovering. Low-power phases of control tower commands (such as descent, landing, taxiing, and standby) can be accounted for within the cruise phase by adding an appropriate percentage of overhead. This overhead can be considered when issuing the actual mission brief. Therefore, the high-power phase and the cruise phase are major factors influencing battery design during battery system design.

[0050] Figure 4 It is based on the identification Figure 3 The flowchart depicts the proposed implementation of the power flow process (stage) during takeoff or climb mode in the system. Arrows leaving DC voltage converter / controller 20a indicate the power flow from HE battery 18a to DC distribution bus 22; arrows leaving DC voltage converter / controller 20b indicate the power flow from HP battery 18b to DC distribution bus 22. Load power demand is greatest during takeoff and climb. Battery system 11 is activated to discharge power generated by HE battery 18a and HP battery 18b to DC distribution bus 22. However, the proportion of total power provided by HP battery 18b is higher than that provided by HE battery 18a. The specific allocation of load power drawn from HE battery 18a and HP battery 18b is determined by system controller 1 and implemented by the two sets of DC voltage converters / controllers 20a / 20b.

[0051] The functions of each DC voltage converter / controller 20a and 20b include: (1) receiving command signals from system controller 12 regarding battery power output requirements; (2) sending back power delivery status to system controller 12; and (3) providing a control and power conversion interface for the associated battery using DC distribution bus 22 during charging and discharging. In any operating mode (e.g., during climb phase), system controller 12 (or flight control system) sends power demand signals to each DC voltage converter / controller to deliver a specific amount of power to DC distribution bus 22. Therefore, the load power distribution between HE battery 18a and HP battery 18b is determined by system controller 12. Each DC voltage power converter / controller then executes a specific control algorithm to deliver the required power to DC distribution bus 22 accordingly.

[0052] Figure 5 It is an instruction based on Figure 3The flowchart depicts a proposed implementation of the system, illustrating the power flow during the cruise phase of aircraft flight. During cruise, the load's power demand decreases significantly. HE battery 18a, under the control of system controller 12, supplies power to all loads (as indicated by the arrow pointing from HE battery 18a to DC distribution bus 22). During this period, HE battery 18a also charges HP battery 18b under the control of system controller 12 (as indicated by the arrow pointing from DC distribution bus 22 to HP battery 18b). Depending on the specific design, HP battery 18b can retain sufficient energy to be deactivated during the cruise phase.

[0053] Figure 6 It is an instruction based on Figure 3 A flowchart illustrating the power flow during the descent / deceleration phase of an aircraft's flight, representing a proposed implementation of the system, is provided. In this context, regeneration is possible. During descent, the aircraft utilizes regenerative power generation, where individual AC motors transform into generators that rotate via propellers, allowing the use of free energy provided by gravity or aerodynamic drag to partially recharge the batteries. Thus, one or both batteries can collect regenerative energy and operate in charging mode. The power flow from inverters / controllers 24a and 24b to HE batteries 18a and HP batteries 18b is... Figure 6 The arrows indicate the direction of the signal: (a) from inverter / controller 24a to DC distribution bus 22; (b) from DC distribution bus 22 to DC voltage converter / controller 20a; (c) from DC voltage converter / controller 20a to HE battery 18a; (d) from inverter / controller 24b to DC distribution bus 22; (e) from DC distribution bus 22 to DC voltage converter / controller 20b; and (f) from DC voltage converter / controller 20b to HP battery 18b.

[0054] Figure 7 It is an instruction in Figure 3 The depicted flowchart illustrates the power flow of the system operating in fault-tolerant mode. If a battery fails, the associated converter / controller deactivates and isolates the failed battery from DC distribution bus 22. Healthy batteries supply power to the load at a reduced power level. In this case, some unnecessary load shedding may be required. Figure 7 In the example depicted, in response to the SOC / SOH manager 16a detecting a fault in the HE battery 16a, the DC voltage converter / controller 20a has been deactivated and the HE battery 18a has been isolated (shown by the dashed box).

[0055] Figure 8 It is an instruction in Figure 3 The diagram depicts a flowchart of the power flow when the system is operating in ground charging mode. In ground charging mode, all propulsion loads are deactivated. Some non-propulsion loads may also be deactivated. In this case, charging station 8, under the control of system controller 12, provides power (as indicated by the arrow pointing from charging station 8 to DC distribution bus 22) to charge HE battery 18a and HP battery 18b.

[0056] The flowcharts and block diagrams in the different depicted embodiments illustrate, in the exemplary embodiments, some possible implementations of the device and method, their architecture, functionality, and operation. In this respect, each block in the flowchart or block diagram can represent a module, segment, function, and / or part of an operation or step. For example, one or more of these blocks can be implemented as program code, in hardware, or as a combination of program code and hardware. When implemented in hardware, the hardware can, for example, take the form of an integrated circuit manufactured or configured to perform one or more operations according to the flowchart or block diagram.

[0057] The embodiments disclosed above use one or more controllers. Such devices include processors or computers, such as central processing units, microprocessors, reduced instruction set computer processors, application-specific integrated circuits, programmable logic circuits, field-programmable gate arrays, digital signal processors, and / or any other circuitry or processing means capable of performing the functions described herein.

[0058] The methods described herein can be encoded as executable instructions embodied in a non-transitory tangible computer-readable storage medium (including, but not limited to, storage devices and / or memory devices). When executed by a processing or computing system, such instructions cause a system device to perform at least a portion of the methods described herein.

[0059] While systems and methods for distributing load power drawn from HE and HP batteries to the electric propulsion of a vehicle have been described with reference to various embodiments, those skilled in the art will understand that various changes can be made without departing from the scope of the teachings herein, and that elements thereof can be substituted with equivalents. Furthermore, many modifications can be made to adapt the teachings to specific situations without departing from the scope of the teachings. Therefore, the claims are not intended to limit the specific embodiments disclosed herein.

[0060] As used in the claims, the term "DC to AC converter (DC-AC converter)" should be interpreted to cover inverters controlled by an inverter controller and their structural equivalents.

[0061] Note: The following paragraphs describe other aspects of this disclosure:

[0062] A1. A system for distributing load power drawn from a battery system to the electric propulsion of a vehicle, the system comprising:

[0063] DC power distribution bus;

[0064] The first DC voltage conversion system connected to the DC power distribution bus;

[0065] A high-energy battery is connected to the first DC voltage conversion system, which is designed to optimally produce DC power during high-specific-energy propulsion.

[0066] A high-energy battery health management system is configured to monitor the state of charge and health of the high-energy battery and generate a first battery state signal representing the state of charge and health of the high-energy battery.

[0067] A second DC voltage conversion system connected to the DC power distribution bus;

[0068] A high-power battery is connected to a second DC voltage conversion system, which is designed to produce DC power optimally during high-specific-power propulsion.

[0069] A high-power battery health management system is configured to monitor the state of charge and state of health of a high-power battery, and generate a second battery status signal representing the state of charge and state of health of the high-power battery; and

[0070] The system controller is configured to receive a first battery status signal and a second battery status signal, and to send commands to a first DC voltage conversion system and a second DC voltage conversion system, which allocate load power drawn from the high-energy battery and the high-power battery according to the propulsion phase of the vehicle and the status of the high-energy battery and the high-power battery as indicated by the first battery status signal and the second battery status signal.

[0071] A2. According to the system described in paragraph A1, the system further includes:

[0072] The first DC-AC converter connected to the DC power distribution bus;

[0073] The first propulsion load is connected to receive AC power from the first DC-AC converter;

[0074] A second DC-AC converter connected to the DC distribution bus; and

[0075] It is connected as a second propulsion load to receive AC power from a second DC-AC converter.

[0076] The system controller is also configured to send commands to the first DC-AC converter and the second DC-AC converter to control the amount and frequency of the corresponding AC power supplied to the first propulsion load and the second propulsion load.

Claims

1. A system for distributing load power drawn from a battery system to the electric propulsion of an aircraft, the system comprising: A high-energy battery designed to optimally produce DC power during high-specific-energy propulsion; A high-energy battery health management system is configured to monitor the state of charge and health of the high-energy battery and generate a first battery state signal representing the state of charge and health of the high-energy battery. A high-power battery designed for optimal DC power production during high-specific-power propulsion; A high-power battery health management system is configured to monitor the state of charge and health of the high-power battery and generate a second battery status signal representing the state of charge and health of the high-power battery. A propulsion load, the propulsion load being configured to produce propulsion using electricity converted from power generated by at least one of the high-energy battery and the high-power battery; A flight computer configured to receive mission input and then output flight data related to propulsion control; as well as A system controller, configured to receive the flight data and the first battery status signal and the second battery status signal, and then, based on the flight phase of the aircraft represented by the flight data and the status of the high-energy battery and the high-power battery represented by the first battery status signal and the second battery status signal, allocates load power drawn from the high-energy battery and the high-power battery for use by the propulsion load. The system controller is further configured to, in response to a first battery status signal indicating a fault condition in the high-energy battery, disable the voltage converter and controller associated with the high-energy battery, disable and isolate the high-energy battery, and distribute the load power to be drawn from the high-power battery in a reduced power scale.

2. The system of claim 1, wherein, The system controller is configured to allocate appropriate load power to be drawn from the high-energy battery and the high-power battery during the climb phase of the aircraft.

3. The system according to claim 1, wherein, The system controller is configured to allocate a first load power to be drawn from the high-energy battery without allocating any load power to the high-power battery during the cruise phase of the aircraft, and wherein the system controller is further configured to allocate a second load power to be drawn from the high-energy battery for charging the high-power battery while drawing the first load power.

4. The system according to claim 1, wherein, The system controller is also configured to allow at least one of the high-energy battery and the high-power battery to be partially recharged using the free energy provided by gravity and aerodynamic drag during the descent phase of the aircraft.

5. The system according to claim 1, wherein, The system controller is also configured to, in response to a second battery status signal indicating a fault condition in the high-power battery, disable and isolate the high-power battery, and distribute the load power to be drawn from the high-power battery in a reduced power scale.

6. A computer-implemented method for distributing load power drawn from a battery system for the electric propulsion of an aircraft, the battery system comprising a high-energy battery designed for optimal production of DC power during high specific energy propulsion and a high-power battery designed for optimal production of DC power during high specific power propulsion, the method comprising the steps of: (a) Calculate flight data related to propulsion control based on mission input received by the flight computer onboard the aircraft; (b) Monitor the state of charge and health status of the high-energy battery; (c) Generate a first battery state signal representing the state of charge and health of the high-energy battery; (d) Monitor the state of charge and health status of the high-power battery; (e) Generate a second battery state signal representing the state of charge and health of the high-power battery; as well as (f) Distribute the load power drawn from the high-energy battery and the high-power battery according to the flight phase of the aircraft represented by the flight data and the states of the high-energy battery and the high-power battery represented by the first battery state signal and the second battery state signal. The method further includes the following steps: in response to a first battery status signal indicating a fault condition in the high-energy battery, disabling the voltage converter and controller associated with the high-energy battery, disabling and isolating the high-energy battery, and distributing the load power to be drawn from the high-power battery in a reduced power scale.

7. The computer implementation method according to claim 6, wherein, Step (e) includes: during the takeoff phase of the aircraft, allocating the appropriate load power to be drawn from the high-energy battery and the high-power battery.

8. The computer implementation method according to claim 6, wherein, Step (e) includes: during the climb phase of the aircraft, allocating the appropriate load power to be drawn from the high-energy battery and the high-power battery.

9. The computer implementation method according to claim 6, wherein, Step (e) includes: during the cruise phase of the aircraft, allocating a first load power to be drawn from the high-energy battery without allocating any load power to the high-power battery; step (e) also includes: while drawing the first load power, allocating a second load power to be drawn from the high-energy battery for charging the high-power battery.

10. The computer-implemented method according to claim 6, further comprising the following steps: At least one of the high-energy battery and the high-power battery is partially recharged using the free energy provided by gravity and aerodynamic drag during the descent phase of the aircraft.

11. The computer-implemented method according to claim 6, further comprising the following steps: In response to a second battery status signal indicating a fault condition in the high-power battery, the high-power battery is deactivated and isolated, and the load power to be drawn from the high-power battery is distributed in a reduced power scale.

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