JP2022544130A - energy delivery system - Google Patents

Abstract

Combining multiple energy storage sources/systems of different chemical composition or physical structure with one common control system that is configured to output energy from the system in response to the different performance characteristics of each system, thus combining An energy delivery system that can optimize various operating characteristics of the system. The control system utilizes a separate variable impedance network for each energy storage system to optimize, for example, the cycle life, depth of discharge, temperature, power delivered, and/or perceived safety of each energy storage system. It is configured to adjust the relative output current or discharge rate of each energy storage system.

Description

This application is part of U.S. patent application Ser. continuation-in-part applications, both of which are hereby incorporated by reference. This application also claims priority to U.S. Provisional Patent Application No. 62/882,817, filed Aug. 5, 2019, which is hereby incorporated by reference. .

The present invention relates generally to energy sources for electronic devices, and more particularly to energy storage systems or systems for delivering energy from energy storage sources.

This article is intended to introduce various aspects of art that may be related to exemplary embodiments of the present disclosure. This discussion is believed to help provide a framework to facilitate a better understanding of certain aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light and not necessarily as an admission of prior art.

There is an ever-increasing reliance on energy devices that can be powered to enable technological convenience. Mainly, power comes from a continuously operating network grid. However, due to remote locations or obstructions where the power grid is unavailable, power must be supplied from off-grid sources. Energy is drawn from off-grid devices and systems using these sources, including chemical energy storage, potential energy storage, or kinetic energy storage, and is designed to be compatible with existing electrical grid frameworks. can be delivered or converted to complete electrical work. Examples of chemical energy storage systems include, but are not limited to, lithium batteries, nickel batteries, flow cell batteries, and lead acid batteries. Examples of potential energy storage systems include, but are not limited to, parametric devices such as lithium capacitors, supercapacitors, and electric double-layer capacitors (“Electric Double-Layer Capacitors, ELDCs”). Examples of kinetic energy storage systems include, but are not limited to, rotating mass systems such as flywheels and other mechanical devices coupled by mechanical/electrical conversion processes. Throughout this disclosure, these terms are used interchangeably in relation to energy delivery devices that are each capable of applying voltage, supplying current, and/or delivering electrical energy to perform work. may be

The performance characteristics of batteries, capacitors, or other energy storage systems are generally determined by the structure of the device and, in the case of electrochemical storage devices, by their chemical composition. Such properties include volumetric energy density (Watt-hours per unit volume), gravimetric energy density (Watt-hours per unit mass), power density (i.e., the rate at which energy can be drawn from the device), charge/discharge cycles. These include, but are not limited to, lifetime, operating temperature range, electrode voltage, overall stability over time, and the like. Moreover, in the case of batteries, some chemistries are more stable during fault conditions, thus producing batteries that are more resistant to thermal runaway; It is considered "safer" than the composition. For example, lithium ion batteries are one of the most commonly used electrochemical energy storage devices. In addition, due to fluctuations in the market price of certain raw materials, there can be significant price differences between battery cells of different compositions when considering the unit price per watt-hour of stored energy. .

International Patent Application No. PCT/US2017/068301 U.S. Patent Application No. 16/760,762

R. Rao et al., "Battery Modeling for Energy-Aware System Design," Computer, Vol. 36, No. 12, pp. 77-87.

Battery cells (also referred to herein as "energy cells") are typically coupled in series and/or parallel combinations to form a battery cell stack (also referred to herein as a "cell stack"). )” or “battery stack”) and, when combined with a suitable control system, form the basis of modern battery-based energy storage/delivery systems. However, an energy delivery system that can safely combine multiple different energy storage sources or systems (including, for example, battery cells based on multiple chemistries) has not yet been provided, and thus the need exists. be. Such energy storage/delivery systems may have not only electrical performance advantages, but also cost, safety, and/or longevity advantages. For example, by carefully combining cells of different chemical composition, an energy storage system can consist of cells that are chemically optimized for cost, safety, and/or extended calendar and cycle life. , another energy storage system may consist of cells that are optimized towards a number of different but otherwise important parameters.

One aspect of the invention provides an energy delivery system. The energy delivery system comprises a first energy storage system, a second energy storage system, a first variable impedance network coupled between the first energy storage system and the output terminal, comprising: A first variable impedance network having an adjustable impedance of unity and a second variable impedance network coupled between the second energy storage system and the output terminal, the second adjustable and (1) adjusting the first adjustable impedance to change the level of the first current delivered to the output terminal by the first energy storage system. and (2) adjusting the second adjustable impedance to reduce the second current delivered to the output terminal by the second energy storage system. and a control system configured to selectively signal the second variable impedance network to change the level.

1 is a schematic diagram of one model of a battery cell; FIG. 4 is a plot of direct current internal resistance (“DCIR”) and open circuit voltage as a function of state of charge for an exemplary battery cell; 1 is a schematic diagram of one model of a battery cell under DC load conditions; FIG. 4 is a graph of a family of voltage versus state of charge characteristic curves, each curve representing a different level of battery current for an exemplary single battery cell; 1 is a schematic diagram of a model of multiple battery cells coupled in series; FIG. 1 is a schematic diagram of a simplified model of multiple battery cells coupled in series; FIG. 4 is a graph of a family of voltage versus state of charge characteristic curves, with each curve taken at a different cell stack current level for an exemplary battery cell stack. 1 is a schematic diagram of a model of a battery cell stack coupled with a variable impedance network; FIG. FIG. 4 is a circuit block diagram in which the variable impedance network includes a plurality of switchable diodes coupled in series; FIG. 4 is a graph demonstrating an example of the effect on the family of characteristic curves of voltage versus state of charge of an exemplary battery cell stack as a result of introducing multiple switchable diodes coupled in series. FIG. 4 is a circuit block diagram in which the variable impedance network includes a plurality of switchable resistive elements coupled in parallel; FIG. 4 is a graph demonstrating an example of the effect on the voltage versus state of charge characteristic curve family of an exemplary battery cell stack as a result of introducing a resistive element. 1 is a block diagram of an energy delivery system; FIG. 1 is a block diagram of an energy delivery system configured in accordance with embodiments of the present disclosure; FIG. 15 is a schematic diagram of one model of the energy delivery system of FIG. 14; FIG. 15 is a schematic diagram of one model of the energy delivery system of FIG. 14, in which multiple switchable diodes are coupled in series in a variable impedance network; FIG. 1 is a flowchart diagram arranged in accordance with an embodiment of the present disclosure; FIG. 1 is a block diagram of an energy delivery system configured in accordance with embodiments of the present disclosure; FIG. 1 is a block diagram of an energy delivery system configured in accordance with embodiments of the present disclosure; FIG. FIG. 4 is a graph of an exemplary family of characteristic curves of voltage during discharge versus state of charge for two battery cell stacks having different chemical compositions. 2 is a plot of the discharge of two different battery cell stacks; 1 is a block diagram of an energy delivery system configured in accordance with embodiments of the present disclosure; FIG. 1 is a graph of a family of voltage versus state-of-charge characteristic curves for two different battery cell stacks having different chemical compositions; 2 is a plot of the discharge of two different battery cell stacks;

It will be appreciated that the particular embodiments described herein are presented by way of illustration and not as limitations on embodiments of the invention. The main features of the invention can be used in various embodiments without departing from the scope of the invention.

Embodiments of the present disclosure are described in terms of electrochemical storage systems (e.g., battery technology) due to their improved energy density compared to other types of energy storage and mechanical devices, as well as their deployed This is due to the ever-increasing applications and uses of However, embodiments of the present disclosure are not limited to the use of battery cells for energy storage systems, and the various embodiments of the present disclosure described herein include, but are not limited to, potential energy It is applicable to use of any type of energy storage system, such as the energy storage systems disclosed herein, including storage systems and kinetic energy storage systems.

Embodiments of the present disclosure combine multiple energy storage sources/systems of different chemical composition or physical structure with one common control system configured to deliver energy from the systems according to different performance characteristics of each system. , thus providing an energy delivery system that can optimize various operating characteristics of the combined system. According to certain embodiments of the present disclosure, energy delivery systems are provided that combine two or more batteries or other energy storage systems coupled in parallel and coupled to a common load. Each combined energy storage system includes battery cells of distinctly different chemical compositions, structures, or methods of operation. According to embodiments of the present disclosure, the control system utilizes a separate variable impedance network for each energy storage system to determine, for example, the cycle life, depth of discharge, temperature, power delivered, and/or perception of each energy storage system. It is configured to adjust the relative output current or discharge rate of each energy storage system to optimize safety. For example, according to embodiments of the present disclosure, an energy delivery system may include two or more battery cell stacks each having a different battery chemistry. Such multiple chemical systems combine two or more cells in series/parallel connection to form two or more battery stacks under the control of a common control system to provide an energy delivery system. It may contain individual groups. In such a non-limiting example, each battery stack can have unique and different performance characteristics therein determined by the chemical composition of the cells. Two or more separate battery stacks may be combined in parallel to create a battery system that will deliver output power to the combined load. According to certain embodiments of the present disclosure, the series cell count of each battery stack may be predetermined to optimally match the total stack voltage of each stack. According to certain embodiments of the present disclosure, the parallel cell count of each battery stack may be predetermined to optimize the Watt-hour capacity of each battery stack as required by the end-use application.

Lithium-ion battery cells can generally be divided into two classes related to energy or power capabilities. Lithium-ion "energy cells" are described as having maximized volumetric or gravimetric energy densities, and have an internal chemical composition that maximizes lithium-ion storage, but the 3C (here , “C” indicates battery capacity) have high internal impedances that limit their ability to deliver large currents. Such energy cells are utilized in applications such as notebook computers and cell phones, where energy is slowly withdrawn over a period of hours or days. Lithium-ion "power cells" are described as having maximized current delivery capability, minimizing internal impedance to allow unhindered lithium-ion mass transfer, thus , has an internal chemical composition that allows it to deliver very large pulsed or continuous currents without lowering the cell terminal voltage to its cutoff limit. A power cell can have a discharge rate greater than 8C up to 50C. Power cells typically have thicker current collectors compared to energy cells. These internal structural and chemical differences result in lower energy storage capacity and cycle life capability compared to energy cells. Power cells are commonly used in applications such as cordless drills and other tools, where high amounts of energy must be delivered over a short period of time and all of the stored energy is delivered within an hour, for example. of discharge time. Within each cell category (power or energy), there may be a wide range of numbers of cell parts with different energy densities and different internal resistance values.

Lithium-ion batteries are available in a wide range of chemical compositions and construction techniques, each with specific relative performance related to cycle life, cost, safety, and energy density listed in the following table (Table 1). with commercial advantages and disadvantages.

Each listed battery type could be said to have a substantially different chemical composition than the others. If a designer were tasked with designing an energy storage system with a required cycle life of 5000 charge and discharge cycles, from this table lithium iron phosphate (LFP) ) or lithium titanium oxide (“lithium titanium oxide, LTO”) would be a better choice, while lithium nickel manganese cobalt (“lithium nickel manganese cobalt, NMC”) would have a relatively shorter cycle life. It is clear that it is not a good choice due to It is also clear that since LFP and LTO are the two highest cost choices available, the relative cost of such systems will be higher. Also, the energy densities of these two cell types are relatively lower, so more cells are required to achieve any given system capacity in Watt-hours.

Interpreting the preceding exemplary information regarding the different relative characteristics of various energy storage sources/systems, for a large subset of the possible energy storage performance requirements, two or more can be configured into a single energy delivery system. of cell chemistries, such that at least some properties of the system are enhanced over those that can be achieved using only one cell chemistry.

To demonstrate the advantages of embodiments of the present disclosure, then a first battery stack comprising LFP cells combined in a Watt-hour capacity ratio of about 60% LFP and about 40% NMC; and An exemplary energy delivery system including a second battery stack energy storage system containing NMC cells is described, which takes advantage of the relatively longer life and enhanced safety properties of LFPs. but at a lower cost point and smaller size due to the lower relative cost and higher energy density characteristics of NMC. According to exemplary embodiments of the present disclosure, system performance and characteristics may be further configurable by adjusting the cell chemistry and cell types used and the ratios in which they are combined. Exemplary embodiments described hereinafter describe a system based on two stacks of energy storage elements, each based on a different chemical composition of a lithium-ion battery, according to various embodiments of the present disclosure. provided, but could also utilize other energy storage systems, such as systems based on a first stack of battery cells and a second stack of ELDCs, allowing optimization for peak pulse power. , allowing faster recharging than is possible using the battery alone. According to embodiments of the present disclosure, the Three or more energy storage systems (including at least two or more of such systems) may be included to further customize the overall system performance and/or characteristics of the energy delivery system.

A battery cell can be modeled as the electronic network shown in FIG. 1 (see, for example, R. Rao et al., "Battery Modeling for Energy-Aware System Design , Computer, Vol. 36, No. 12, pp. 77-87, December 2003). The commonly accepted model is the equivalent of an ideal voltage source, representing the open-circuit voltage (referred to herein as either “OCV” or “V _oc ”), the current (I _s ) through contains a flowing internal series resistance (R _s ) and a reactive component (R _n C _n ) of a combination of series and/or parallel connected resistors and capacitors, where I _n is the reactive component is the current flowing through Note that the model may contain a large number (ie, n, where n ≧ 1) of RC elements contributing to the total reactive component of the cell impedance.

The voltage at the battery terminals (“ _Vbatt” ) under direct current (“DC”) load conditions is given by the following equation:
V _{batt = V oc -RsIs -ΣRnIn}

A battery's internal series resistance (R _s +ΣR _n ) is sometimes referred to as direct current internal resistance (“DCIR”). DCIR varies with the state of charge (“SOC”) of the battery.

FIG. 2 illustrates a graph showing both battery cell DCIR and OCV as a function of SOC for a typical NMC battery cell. The higher the state of charge, the higher the _Voc voltage and the lower the DCIR. DCIR increases at low state of charge, especially when SOC drops below approximately thirty percent (30%).

Note that the time-based component can dominate transient response and Faraday contributions during abrupt load changes and charge and/or discharge cycles. When considering the overall behavior of a battery cell under DC load conditions where the current does not change with time, the resistive elements can be added and the capacitive elements can be neglected, so the model is
V _batt =V _oc -R _batt I _batt
can be simplified to

This simplified cell model is shown in FIG. As a result, V _batt can be characterized by a family of voltage versus SOC curves (also referred to herein as VI characteristic curves) at various currents taken at different I _batt current values. This family of VI characteristic curves for a typical single NMC cell is shown in FIG. (In FIG. 4 and other figures showing graphs of voltage vs. SOC curves, each line represents the voltage at a different current value related to C, the rated capacity of the battery.)

Referring to Figure 5, when a large number (n) of identical battery cells are coupled in series, the model is
V _batt =n(V _oc -R _batt I _batt )
where n is the number of battery cells in series. A simplified model is shown in FIG.

Referring to FIG. 7, similar to the single battery cell example described above, such a series-connected cell system (11 cells in this non-limiting example are connected in series). An exemplary family of VI characteristic curves can be generated for a typical NMC cell battery stack described above).

Referring to FIG. 8, the battery stack may be coupled to a variable impedance circuit (referred to herein as either " _Zvar " or " _Zvariable "). The term Z _var denotes the variable impedance of a circuit that can be configured as a network of switchable elements (hence the variable impedance circuit will also be referred to herein as the "variable impedance network"). For any given value of output current, the term _Zvar means that each energy source so equipped (e.g., battery cell stack) can be adjusted to its normal characteristic voltage by adjusting the value of _Zvar . Allows the position of the V _batt output characteristic curve to be shifted downward relative to the position of the curve (ie the discharge curve observed when Z _var =0).

Embodiments of the present disclosure may be configured to utilize any suitable circuitry in variable impedance circuits and/or circuitry. International Patent Application No. PCT/US2017/068301 (hereinafter referred to as "PCT/US2017/068301") describes a variable impedance network in accordance with various embodiments of the present disclosure described herein. Exemplary implementations of circuitry including switchable elements that can be utilized in are disclosed. As shown in FIG. 9, a first implementation disclosed in PCT/US2017/068301 (FIG. 6 from PCT/US2017/068301 is given as FIG. 9) includes several Utilizing series-connected switchable diode circuits 610a...610c, they are selectively inserted into the circuit according to a control algorithm performed by a control system 602 which can monitor the system 600 in real time. or removed from the circuit (using switching elements, eg, FETs). Although the embodiment shown in FIG. 9 shows three series-connected switchable diode circuits 610a-610c, more or fewer such switchable diode circuits may be used in an accurate system. May be utilized depending on configuration and end use requirements. Note that the remaining elements shown in FIG. 9 are not further described for simplicity, but can be referenced by reviewing PCT/US2017/068301.

FIG. 10 shows the effect on the position of the characteristic curve when several series-connected diodes (in this case five ideal diodes) are introduced into the circuit. Note that each characteristic curve is shifted downward (lower voltage) by the same amount relative to no impedance insertion (ie, Z _variable =0). In this non-limiting example, Z _variable =5*Vf, where Vf is the forward voltage of the ideal diode. Note that the battery current has no effect on the level of this shift, ie the curve for each current level shifts by the same amount. The variable nature of this embodiment, which uses series-connected switchable diodes, allows any number of diodes (i.e., from zero diodes up to the maximum number of implemented diodes) to be added or added to the circuit at any time. It arises from the fact that it can be removed from the circuit. Accordingly, the VI characteristic curve associated with an implemented battery cell stack can be shifted upwards or downwards at any time during operation of an energy delivery system configured with such variable impedance networks.

FIG. 11 provides a second exemplary implementation of circuitry including switchable elements disclosed in PCT/US2017/068301 (FIG. 7 from PCT/US2017/068301 is provided as FIG. 11). ). In this exemplary implementation, circuitry including switchable elements is configured as a parallel connection of switchable resistive elements 750a-750d. Each switchable resistive element may be selectively inserted into or removed from the circuit (using a switching element, eg, a FET) according to a control algorithm performed by control system 702. , the total impedance of a switchable resistor network is determined by the number of switchable resistive elements that are switched on or off at a given time. Adding or subtracting resistance in such circuitry in much the same way as described with respect to FIG. 9 will result in a shift in the position of the VI characteristic curve of the battery cell stack. Note that the remaining elements shown in FIG. 11 are not further described for simplicity, but can be referenced by reviewing PCT/US2017/068301.

FIG. 12 shows the characteristic curve with a circuit arrangement including a switchable resistive element set to a value of 0 ohms (ie Z _variable =0) and a value of 1 ohm (ie Z _variable =1 ohms) is shown in comparison to the curve with a circuit arrangement that includes a switchable resistive element. As can be seen, the resulting characteristic shift is of a different nature than demonstrated for the exemplary implementation when a switchable diode is implemented. Rather than all curves being shifted downward by an equal amount as shown in FIG. 10, the magnitude of the downward shift of each curve is proportional to the current represented by each curve. This results in the various characteristic curves "spreading apart" rather than all curves being shifted downward by a fixed voltage value. The voltage drop across a resistor is current times resistance, while the voltage drop across an ideal diode is a fixed voltage independent of current. So for a network of switchable resistive elements the effect on the VI characteristic curve is current dependent (e.g. 0 current results in 0 voltage drop, 1× current results in , resulting in a single voltage drop, twice the current resulting in a double voltage drop, etc.). This means that the VI characteristic curve at each particular current level will "spread" with resistance, the higher the resistance inserted, the more spread will result. do. For switchable diodes, the forward voltage drop is fixed regardless of the magnitude of the current. Therefore, all VI characteristic curves are shifted downward by the number of diodes that are switched into the circuit (ie, the number of diodes that are not shorted by the switch). Regardless of the amount of current present in the diodes, one diode will all shift the curve downward by the same amount (e.g., Vf=0.75V), and two diodes will shift the curve downward by 1.5V. , 5 diodes shifts the curve downward by 3.75V, and so on.

Referring to FIG. 13, a system 1300 is shown where a battery stack 1301 includes multiple series-connected battery cells and a variable impedance network 1302 presents a voltage at the V _o Positive terminal. For each cell in battery stack 1301 , its voltage is monitored by an analog front end measurement device (“analog front end measurement device, AFE”) 1303 . AFE 1303 may also collect temperature data and deliver the collected data to control system (eg, microcontroller “MCU”) 1304 . The cell stack 1301 can be coupled to V _o Negative through a sense resistor (Rsense) 1305 . Each side of the sense resistor 1305 is coupled to a fuel gauge integrated circuit (“IC”) 1306 to generate a voltage representing the value of the battery current (i _o ) whenever current is present across the sense resistor 1305 . Can be provided to gauge IC1306. Fuel gauge IC 1306 can communicate information regarding the state of charge (“SOC”) of battery stack 1301 to MCU 1304 . MCU 1304 is coupled to variable impedance network 1302 and controls variable impedance network 1302 . MCU 1304 can implement one or more control algorithms configured to control (eg, optimize) the operating state of system 1300 in a predetermined manner. For example, a control algorithm operated by control system 1304 determines the state of battery stack 1301 and manipulates variable impedance network 1302 to adjust the position of the VI characteristic curve that determines this parameter, V _o of system 1300 . It may be configured to control (eg, adjust or modify) the voltage presented to the Positive terminal. MCU 1304 may be configured to communicate data and/or information to an external host system (eg, via communication link or bus 1307).

Referring to FIG. 14, shown is an energy delivery system 1400 configured in accordance with an embodiment of the present disclosure. In energy delivery system 1400, a first battery cell stack 1401a is coupled in parallel to a second battery cell stack 1401b, where battery cell stacks 1401a and 1401b each have similar control circuitry and monitoring. can be coupled to the circuit. The battery cell stacks 1401a, 1401b may be coupled to a common control system (eg, microcontroller "MCU") 1404 whereby parametric information from each battery stack is collected (eg, simultaneously) and controlled by the variable impedance network 1402a. , 1402b may be implemented to control the operation of either or both. The voltage of each cell in battery stack 1401a can be monitored by analog front-end measurement equipment (“AFE”) 1403a. AFE 1403 a may also collect temperature data and deliver the collected data to control system 1404 . Battery stack 1401a may be coupled to V _o Negative through sense resistor (Rsense) 1405a. Each side of the sense resistor 1405a is coupled to a fuel gauge integrated circuit (“IC”) 1406a to generate a voltage representing the value of the battery current (i ₁ ) whenever current is present in the sense resistor 1405a. Can be provided to gauge IC1406a. The fuel gauge IC 1406a can communicate information to the control system 1404 regarding the state of charge (“SOC”) of the battery stack 1401a. The voltage of each cell in battery stack 1401b may be monitored by AFE 1403b. AFE 1403b may also collect temperature data and deliver the collected data to control system 1304 . Battery stack 1401b may be coupled to V _o Negative through sense resistor (Rsense) 1405b. Each side of sense resistor 1405b can be coupled to fuel gauge IC 1406b to provide fuel gauge IC 1406b with a voltage representing the (i ₂ ) value of the battery current whenever current is present in sense resistor 1405b. can. The fuel gauge IC 1406b can communicate with the control system 1304 information regarding the SOC of the battery stack 1401b. Essentially, the fuel gauge ICs 1406a, 1406b measure the instantaneous current, as well as the battery temperature, and then, from measured or digitally delivered data, determine the average current, instantaneous state of charge, and the battery stack experience. It can be configured to calculate the number of charge/discharge cycles performed, the resistance of the battery stack, and other parameters.

Note that according to certain embodiments of the present disclosure, the V _o Positive output terminal is common between variable impedance networks 1402a, 1402b. As a result, according to embodiments of the present disclosure, variable impedance networks 1402a, _1402b control the output voltage presented to terminal Vo Positive from control system 1404, as is done in system 1300. can be configured to control the level of current that flows through each variable impedance network 1402a, 1402b and is delivered to the output terminals under selective control by signals of . Selective control of the variable impedance networks 1402a, 1402b by the control system 1404 may be performed such that the battery stacks 1401a, 1401b, respectively, are maintained within predetermined output current ranges according to predetermined performance criteria of the energy delivery system 1400. can.

Control system 1404 may be configured to communicate data and/or information to external host systems (eg, via communication link or bus 1407). Internal communications between various components and/or external communications from control system 1404 may be wired or wireless. Available communication protocols include, but are not limited to, SMB, I2C, RS232, TTL, Serial, USB, CAN, Network.

In a non-limiting example, variable impedance network 1402a, 1402b includes a plurality of switchable resistive elements, such as the configuration of switchable resistive elements 750a...750d utilized in system 700 of FIG. You can Each switch 710a...710d can be individually opened or closed by the control system 1404 according to a predetermined control algorithm. Resistors 750a...750d can be configured with the same resistance value or with different resistance values. By altering the number of resistors 750a...750d coupled in parallel by their corresponding switches 710a...710d, the effective resistance of either or both of the variable impedance networks 1402a, 1402b can be adjusted to a predetermined range. (eg, from a predetermined minimum resistance value to a predetermined maximum resistance value).

Energy delivery system 1400 can be represented by the simplified model shown in FIG.
V _o Positive=V ₁ -R ₁ *i ₁ -i ₁ *Variable R1
V _o Positive=V ₂ -R ₂ *i ₂ -i ₂ *Variable R2
It can be described by i ₁ +i ₂ =i output.

Energy delivery systems 1400 have different sets of operating parameters (e.g., due to different materials and/or chemical compositions), where cell stack 1401a is configured with a higher cycle life relative to cell stack 1401b. and cell stack 1401b includes cells configured with a lower cycle life relative to cell stack 1401a, but may include cells of higher relative energy density. Consider a typical embodiment. Assume that the energy capacities of the two cell stacks are approximately the same. According to embodiments of the present disclosure, it is advantageous for the operation of energy delivery system 1400 that the cell stack with the higher relative cycle life (i.e., cell stack 1401a) delivers the majority of the energy during discharge. can be. For example, according to embodiments of the present disclosure, the control system 1404 ensures that the current drawn from the cell stack 1401a during discharge is less than the current drawn from the cell stack 1401b to take advantage of the longer cycle life of the cell stack 1401a. It can be configured to double, or in other words, the periodic energy drawn from cell stack 1401a is twice the periodic energy drawn from cell stack 1401b. Under such an exemplary operating scenario, the equations are:
i ₁ =2*i ₂ (i ₁ is always twice i ₂ )
V _o Positive=V ₁ -R ₁ *2*i ₂ -2*i ₂ *Variable R1, and
V _o Positive=V ₂ -R ₂ *i ₂ -i ₂ *Variable R2
can be rewritten.

The values V ₁ , V ₂ , R ₁ , and R ₂ can be found from cell characterization curves (such as those shown in FIG. 2) associated with the types of battery cells utilized in the cell stacks 1401a, 1401b, It is therefore trivial to solve the equations for the values of Variable R1 and Variable R2 so as to maintain the condition i ₁ =2*i ₂ and thus configure the variable impedance networks 1402a, 1402b with appropriate values.

Energy delivery system 1400 can also be represented by the simplified model shown in FIG. 16, where variable impedance networks 1402a, 1402b are each a switchable impedance network utilized in system 600 of FIG. It includes a plurality of switchable diodes, such as the arrangement of diodes 610a...610c. Each of the switchable diodes 610a...610c is coupled with a switch (eg, FET) that can bypass any current around the diode. The switches can be opened or closed according to control signals received from control system 1404 (eg, similar to control signals 621a...621c of FIG. 9). Each diode can be configured with the same or different forward voltage drop (Vf) values. The number of diodes whose associated switches are open, thus contributing to the forward voltage drop for their associated variable impedance networks 1402a, 1402b, and the number of diodes whose associated switches are closed, thus their associated variable impedance networks 1402a , 1402b is adjustable by the control system 1404, so the sum of the voltage drops is variable.

Similar to the example described with respect to Figure 15, this system uses the equation
V _o Positive=V ₁ -V _var1 -i ₁ *R _1
VoPositive =V2 _{- Vvar2 -} i2* _R2
It can be described by i ₁ + i ₂ =i outputs.

Again, as in the previous example, the energy delivery system 1400, for example, where cell stack 1401a includes cells configured with a very high cycle life relative to cell stack 1401b, cell stack 1401b Consider including two different battery cells that may include cells configured with a lower cycle life but higher relative energy density for cell stack 1401a. Assume that the energy capacities of the two cell stacks are approximately the same. Also, as in the previous example, we want i ₁ =2*i ₂ , so the equation becomes
i ₁ +i ₂ =i output
i ₁ =2*i ₂ (i ₁ is always twice i ₂ )
_VoPositive =V1 _{- Vvar1-2 *} i2* _{R1
VoPositive} =V2 _{- Vvar2 -} i2* _R2
Consider a rewritten energy delivery system 1400 .

_Again , the values V1, V2, _R1 , and _R2 are found from a cell characterization curve such as that shown in FIG. ₃ , thus maintaining the condition i1 _{= 2} *i2. It is trivial to solve the equations for the exact values of V _var1 and V _var2 as follows, and configure the number of active diodes in each impedance network with appropriate values.

Values V1, V2, _R1 , and _R2 can be known from cell characterization curves (such as those shown in _FIG . ₂ ) associated with the types of battery cells utilized in cell stacks 1401a, 1401b. and therefore solve the equations for the values of V _var1 and V _var2 to maintain the condition i ₁ =2*i ₂ , and thus the number of active diodes in each variable impedance network 1402a, 1402b by appropriate values. The configuration is self-explanatory. Since the value of Vf for each diode is a fixed characteristic value depending on semiconductor technology and device type, the exact value of each of the variable impedance networks 1402a, 1402b cannot be precisely adjusted, but rather It is important to note that it is some fixed multiple of the Vf value.

According to embodiments of the present disclosure, implementations of the energy delivery system 1400 are implemented with the variable impedance networks 1402a, 1402b utilizing switchable resistive elements, switchable diodes, or combinations thereof. Whether or not implemented, optionally embodying the formulas described with respect to either FIG. 15 or FIG. Control algorithms programmed within the control system 1404 may be utilized. Additionally, according to embodiments of the present disclosure, battery cell eigenvalues V ₁ , V ₂ , R ₁ , and R ₂ may be determined from their individual cell characterization curves. Since such values are highly variable with cell state of charge, temperature, and age, such values can be incorporated into some suitable database, such as a lookup table, to capture characterized data and A model may be created to estimate the properties.

According to embodiments of the present disclosure, control system 1404 may utilize control algorithms based on iterative approximation. For example, the initial state of the variable impedance networks 1402a, 1402b may be configured (eg, by solving the descriptive equations) before the energy delivery system 1400 is initialized and any energy discharge begins. . Then, once the discharge begins, the control system 1404 dynamically changes the energy delivery system 1400, such as the voltage, current, and SOC of each cell stack 1401a, 1401b, rather than performing continuous equation processing. It may loop repeatedly through a parametric measurement step in which operating conditions are measured, after which the output currents or other selected parameters of each cell stack 1401a, 1401b are measured relative to each other and targeted. A comparison step follows in which the performance is compared, followed by a correction step (e.g., a small in discrete steps). A delay may be added to the loop to allow the battery parameters to stabilize after each adjustment to either of the variable impedance networks 1402a, 1402b. For example, using the previous example of the energy _delivery system _{1400 described} with respect to _FIG . Constantly maintaining i1 to _a fixed percentage of i2 _only when SOC is above 25% and a different fixed percentage when SOC of cell stack 1401a is below 25%, or between cell stack temperatures may be configured to reduce the current of the hottest cell stack to 10% of the current of the coldest cell stack whenever the difference in . The preceding examples are not limited to the possible variations in possible control algorithms.

FIG. 17 shows a flowchart of a process 1700 including an exemplary control algorithm performed within the control system 1404 of the energy delivery system 1400 according to embodiments of the present disclosure. As further described, process 1700 may also be performed within control system 1804 of system 1800 described with respect to FIGS.

The energy delivery system 1400 may be initialized (startup). At processing block 1701 (Access Machine State), the state of the energy delivery system 1400 may be determined. For example, voltage (e.g., of cells in battery stack 1401a, 1401b via AFEs 1403a, 1403b), current (e.g., sensed by sense resistors 1405a, 1405b), (e.g., battery The temperature of the cells within the stack 1401a, 1401b) may be measured and this data may be collected by the control system 1404. FIG. Using this data, at processing block 1702 a determination can be made as to whether the energy delivery system 1400 is ready to discharge. If not, at processing block 1710 some corrective action can be taken.

For example, if the collected data determines that one or both of the cell stacks 1401a, 1401b are not fully charged, a charging current may be applied from an external energy source ( For example, see chargers 603, 703 in FIGS. 9 and 11, respectively). A cooling system (not shown) may be activated when the collected data determines that one or more cells in one or both of the cell stacks 1401a, 1401b are too hot. If the manual interlock is engaged, energy delivery system 1400 may be configured to wait for it to clear. After corrective actions have been initiated, process 1700 can return to process block 1701 where within control system 1404 process 1700 is ready to discharge energy of energy delivery system 1400 to a load (not shown). This loop may continue until it is determined.

Once the process 1700 within the control system 1404 determines that the energy delivery system 1400 is ready to discharge, both variable impedance networks 1402a, 1402b can be set to predetermined initial values. These initial values may be determined from equations performed within control system 1404 in real time (see, e.g., equations discussed with respect to FIGS. 15 and 16), or the SOC measured in processing block 1701, cell stack voltage, It may be set from a predetermined lookup table of predetermined initial values based on parameters such as temperature and/or from a predetermined lookup table based on VI characteristic curves associated with the cell stacks 1401a, 1401b.

Once the initial values of the variable impedance networks 1402a, 1402b are set, the process 1700, for example, couples the load circuits (eg, to the V _o Positive terminal and the V _o Negative terminal) to the energy delivery system 1400 while simultaneously coupling the load You can wait for the current discharge to start. This may include process 1700 looping back to process block 1701 . Once the discharge current is detected in processing block 1704, processing block 1705 extracts parameters ("parametric data ( AFEs 1403a, 1403b and current sensors 1405a, 1405b are utilized to collect, for example, voltage, current, temperature, SOC, charge/discharge cycles, resistance, impedance, etc.). At processing block 1706, this data may be analyzed to determine if continued discharge is permissible. For example, parameters that can terminate discharge include cell stack voltage below safe limits, cell stack current above safe limits, cell stack temperature outside safe limits, engagement of manual safety interlocks, and/or control system or any other disturbance in the measurement system. If it is determined at processing block 1706 that the discharge cannot be safely continued, process 1700 may proceed to processing block 1710 to take appropriate action.

If it is determined at processing block 1706 that the discharge can be safely continued, processing block 1707 determines if either or both of the variable impedance networks 1402a, 1402b need adjustment. can be done. For example, according to a non-limiting embodiment of the present disclosure, a control algorithm performed in the control system 1404 calculates the average current of operation (eg, measured by the current sensors 1405a, 1405b over a predetermined time period) to the cell stack. It can be configured to maintain equality for both 1401a, 1401b. As a result, if the most recently collected parametric data indicates that the average current in cell stack 1402a is higher than the average current in cell stack 1401b, the control algorithm performed by control system 1404 is to apply a correction It can be configured to take one of two possible actions. Either the MCU 1404 signals the switches in the variable impedance network 1402a to increase their total impedance value, or the control system 1404 signals the switches in the variable impedance network 1402b to increase their total impedance value. It is possible to either signal to decrease. Both options may be acceptable, but the control system 1404 may prioritize one of these corrective actions over the other according to any one or more predetermined factors. can be configured to For example, variable impedance network 1402a may already be set near its minimum impedance value, in which case control system 1404 instead causes variable impedance network 1402b to decrease its impedance value. may be configured. Since control system 1404 is configured to know the state of both variable impedance networks 1402a, 1402b, control system 1404 can be configured to select the most appropriate action. Once the corrective action is determined in processing block 1707, the control system 1404 causes the variable impedance networks 1402a, 1402b to perform the action (i.e., apply the new impedance setting) in processing block 1708. Send one or more control signals to one or both of them. _Once the new settings have been applied, process ₁₇₀₀ performs a , may be configured to implement a delay routine (processing block 1709). Once this delay has expired, process 1700 can return to process block 1705 . Note that the aforementioned algorithms described with respect to processing block 1707 are exemplary and non-limiting for embodiments of the present disclosure.

Embodiments of the present disclosure are further illustrated by the following examples, which are included to illustrate the presently disclosed subject matter and should not be construed as limiting. The examples confirm that embodiments of the present system are capable of conveying and publishing one or more pieces of information under various conditions that exemplify various environments in which embodiments of the present system may be utilized. I will explain the verification carried out for this purpose.

Referring to FIG. 18, an energy delivery system 1800 configured according to embodiments of the present disclosure is shown. In energy delivery system 1800, a first battery cell stack 1801a is coupled in parallel with a second battery cell stack 1801b, where each battery cell stack is connected to similar control and monitoring circuitry. can be combined. Battery cell stacks 1801a, 1801b may be coupled to a common control system (eg, microcontroller "MCU") 1804 whereby parametric information from each battery stack is collected (eg, simultaneously) and controlled by a variable impedance network. A control algorithm may be implemented to control the operation of either or both of 1802a, 1802b. The voltage of each cell in battery stack 1801a can be monitored by analog front-end measurement equipment (“AFE”) 1803a. AFE 1803 a may also collect temperature data and deliver the collected data to control system 1804 . Battery stack 1801a may be coupled to V _o Negative through sense resistor (Rsense) 1805a. Each side of the sense resistor 1805a is coupled to a fuel gauge integrated circuit (“IC”) 1806a to generate a voltage representing the value of the battery current (i ₁ ) whenever current is present in the sense resistor 1805a. Can be provided to gauge IC1806a. The fuel gauge IC 1806a can communicate information to the control system 1804 regarding the state of charge (“SOC”) of the battery stack 1801a. The voltage of each cell in battery stack 1801b may be monitored by AFE 1803b. AFE 1803b may also collect temperature data and deliver the collected data to control system 1804 . Battery stack 1801b may be coupled to V _o Negative through sense resistor (Rsense) 1805b. Each side of the sense resistor 1805b can be coupled to a fuel gauge IC 1806b to provide a voltage to the fuel gauge IC _1806b representing the value of the battery current (i2) whenever current is present in the sense resistor 1805b. can. The fuel gauge IC 1806b can communicate information regarding the SOC of the battery stack 1801b to the control system 1804. Control system 1804 may be configured to communicate data and/or information to external host systems (eg, via communication link or bus 1807). Internal communications between various components and/or external communications from control system 1804 may be wired or wireless. Available communication protocols include, but are not limited to, SMB, I2C, RS232, TTL, Serial, USB, CAN, Network.

Each variable impedance network 1802a, 1802b includes a number of diodes along with the bypassing switches described with respect to FIG. 16, for example. Although the number of diodes and corresponding switches are shown to be the same in each variable impedance network 1802a, 1802b, the actual number may be the same or different between the two. good. The number of diodes present in each variable impedance network 1802a, 1802b determines the maximum voltage drop from the high side of each battery cell stack 1801a, 1801b to the output terminal V _o Positive, which is the maximum voltage drop across all diodes is the sum of the forward voltage (Vf) drops of According to certain embodiments of the present disclosure, one or more of the diodes may have different parametric characteristics such that different forward voltage drops are achieved with each diode. The number of active diodes and the number of diodes bypassed in each variable impedance network 1802a, 1802b is such that the number of diodes bypassed and the number of diodes bypassed in each of the variable impedance networks 1802a, 1802b provide a predetermined amount of downward shift in the characteristic curve of each battery stack 1801a, 1801b, thus increasing the energy It can be controlled by a control system 1804 to affect the load current contribution of each cell stack 1801a, 1801b in the delivery system 1800.

FIG. 18 shows the variable impedance networks 1801a, 1801b such that the full forward voltage drop of all the diodes in each variable impedance network 1802a, 1802b is achieved between each battery stack 1801a, 1801b and the output terminal V _o Positive. Energy delivery system 1800 is shown with switches open at both 1802a, 1802b. Although FIG. 18 discloses a dual cell stack energy delivery system, embodiments of the present disclosure include three or more cells coupled in various series and/or parallel combinations and monitored and controlled by control system 1804. It may be configured by a battery stack.

According to an exemplary embodiment of the energy delivery system 1800, the battery stack 1801a includes battery cells (eg, LFP or LTO) configured with relatively high cycle life battery chemistries, thereby , its terminal voltage and VI characteristic curve overlap those of battery stack 1801b, which includes NMC battery cells, as illustrated by the exemplary VI characteristic curve in FIG. 20, for example. The LFP stack 1801a contains 13 cells with a typical full charge voltage between 44V and 46.8V (3.6V/cell). NMC battery stack 1801b contains 11 cells with a typical full charge voltage between 43.3V and 46.2V (4.0V/cell). Both the LFP battery stack and the NMC battery stack can be charged to the same voltage at full charge, or alternatively, the voltage of one of the battery stacks can be maintained higher than the voltage of the other battery stack. Additionally, the maximum charging voltage may be adjusted. In this embodiment, the LFP cell stack 1801a and the NMC cell stack 1801b are configured to have similar chemical capacities in ampere hours.

Referring to FIG. 19, in the default mode of operation, the system 1800 can be configured such that all of the diode switches in both variable impedance networks 1802a, 1802b are closed, bypassing the diodes, thereby The VI characteristic curve of each cell stack 1801a, 1801b will be exhibited at the V _o Positive terminal without any influence from the variable impedance networks 1802a and 1802b. Within the load current range of interest, the cell stacks 1801a, 1801b will, at all times during discharge, have their VI characteristics They will share the load based on their stack voltages as determined by the curve. At any given moment, the current in each cell stack is such that current i1 in LFP stack _1801a and current i2 in NMC stack _1801b are in their respective VI characteristic curves corresponding to equal voltages on the cell terminals. Become. The greater the difference in the positions of the VI characteristic curves, the greater the current difference between stacks 1801a and 1801b. Referring to the battery stack voltage as a function of state of charge shown in FIG. , NMC cell stack 1801b has a higher terminal voltage for about the first 10% depth of discharge. During the rest of the depth of discharge, the LFP cell stack 1801a has a higher terminal voltage and proportionally higher current share during discharge.

Figure 21 shows a graph of an exemplary discharge of the system 1800 configured in Figure 19 at a constant power of 100 W (the diode switches in both variable impedance networks 1802a, 1802b are all closed). , both become Z _var =0, which causes the battery stack voltage to be directly coupled to the output load). Each battery stack 1801a, 1801b is charged to a starting voltage of 44V. The discharge duration is approximately 1.8 hours. Each of the battery stacks 1801a, 1801b can be discharged and current balanced based on the VI characteristic curve of each battery stack. Consistent with the voltage curves of FIG. 20, when a load is coupled to the energy delivery system 1800, FIG. 21 shows that current i1 rises in LFP stack _1801a and voltage drops rapidly below that of NMC stack 1801b. is shown. This is due to the steepness of the open circuit voltage curve of the LFP chemistry near the full state of charge and the shift of the operating point from the light load VI curve to the higher current VI curve. The NMC stack 1801b soon achieves a slightly higher terminal voltage to the LFP stack 1801a and delivers a significant portion of the load current. After approximately 0.18 hours of discharge, the NMC voltage drops due to its reduced SOC and the stack voltage begins to droop into the range of the LFP stack 1801a. At this point in the discharge, LFP stack 1801a begins to deliver a higher rate of current. From this point on, the LFP stack 1801a maintains a higher voltage and a higher current than the NMC stack 1801b, causing the LFP stack 1801a to drop in SOC faster than the NMC stack 1801b and eventually deplete. The SOC of LFP stack 1801a slowly moves from 100% to about 5% over a period of about 1.4 hours. At this point in the discharge event, the LFP stack 1801a is nearly depleted of energy, causing its terminal voltage to drop below the terminal voltage of the NMC cell stack 1801b. NMC cell stack 1801b then takes over, increasing its current occupancy to nearly 100% for the last few minutes of discharge.

FIG. 22 illustrates an exemplary embodiment of the operation of processing blocks 1707-1708 of system 1800, the purpose of which is to bias the energy discharge from NMC stack 1801b to LFP stack 1801a so that from the beginning of the discharge the LFP The trick is to configure system 1800 so that LFP current i1 is always higher _than NMC current i2 until the energy in stack _1801a is completely depleted. In this exemplary embodiment, the diode switches in variable impedance network 1802a of LFP stack 1801a are closed to produce Z _var =0 for LFP stack 1801a and in variable impedance network 1802b for NMC stack 1801b. diode switch is opened to produce the maximum value of Z _var (Z _var =3*Vf). As can be seen from the graph shown in Figure 23, the LFP VI characteristic curve remains as in the previous example (see Figure 20), but now the NMC VI characteristic curve is equal to 3*Vf. is shifted downward by the amount.

As expected, based on the configuration of the energy delivery system 1800 shown in Figure 22, the voltage curve of the NMC stack 1801b is offset lower than the LFP stack 1801a due to the contribution of _Zvar . become. A shifted voltage curve is shown in FIG. The LFP voltage is higher than the NMC voltage for most of the SOC range, and this downward shift in the NMC voltage caused by its associated Z _var translates into a significant current bias into the LFP stack 1801a during most of the discharge. be.

FIG. 24 shows an exemplary discharge graph for the system 1800 configured in FIG. 22 at a constant power of 100W. Each battery stack 1801a, 1801b is charged to a starting voltage of 44V. The discharge duration is approximately 1.8 hours. In this example, the diode switch in variable impedance network 1802a is closed causing Z _var =0 and the LFP battery stack voltage is directly coupled to the output load V _o Positive while variable impedance network 1802b The diode switch in is left open, causing the NMC stack voltage to be offset downward by 3*Vf. The respective operating points of cell stacks 1801a, 1801b are adjusted to their respective VI characteristics such that the output current of energy delivery system 1800 is biased much more towards LFP stack 1801a than the examples of FIGS. become a point on the curve. Contrasting the discharge shown in FIG. 24 with the discharge shown in FIG. 21, due to the lower position of the NMC VI characteristic curve, initially NMC stack 1801b It can be seen to deliver approximately 20%. As the system operating point transitions through the VI characteristic curve according to the changing SOC of the various battery stacks, the NMC current ( _i2 ) initially rises above the LFP current ₍ i1) and then There is no "inversion" of the current, a sudden reversal of short duration. LFP stack 1801a maintains a higher percentage of total discharge current until such time as LFP stack 1801a is nearly depleted. The SOC of LFP stack 1801a slowly transitions from 100% to about 5% over a period of about 1.4 hours. At this point in the discharge event, the LFP cell stack 1801a is nearly depleted of energy, and in a low state of charge, such as in this case, the LFP VI characteristic curve is at a much higher NMC SOC, with the corresponding NMC VI The characteristic curve drops below and thus NMC stack 1801b takes over, steadily increasing its proportion of total power until the end of discharge.

Tuning each variable impedance network 1802a, 1802b, and thereby also the position of the corresponding VI characteristic curve, between different cell stacks to suit a particular purpose and optimize a particular performance characteristic. can be shifted to bias the discharge current towards one stack or the other. For example, biasing the discharge current towards a battery stack with a relatively high cycle life and from a stack with a relatively low cycle life results in hundreds of moderate duration discharge events. , higher cycle life battery stacks will deliver many times more cycle energy than other battery stacks.

The total depth of discharge of the energy storage system will depend on the load duration. Battery stacks often complete only a partial discharge where 40% to 70% of the total stored energy is delivered. As demonstrated in the example in FIG. 24, for a partial discharge lasting 1.3 hours, the high cycle life LFP cell stack 1801a discharged 95% of its energy (completed 0.95 cycles) and the NMC stack 1801b: Only about 40% of its energy has been discharged (only 0.40 cycles completed). If this same discharge were performed 1000 times, the LFP cell stack 1801a would be considered to have completed 950 cycles compared to only 400 cycles completed by the NMC cell stack 1801b.

According to various embodiments of the present disclosure, energy delivery systems 1400 and 1800 may be similarly configured, whereby the control system, AFE, fuel gauge IC, and sense resistor are connected to the energy storage to which they are coupled. They operate in substantially similar fashion, except for modifications that may be made to either system, depending on the type of system and the type of configuration utilized within the variable impedance network.

A digital communication link 1407, 1807 may be configured to transmit certain data from the control system 1404, 1804 to a host system (not shown). Energy delivery systems such as 1400, 1800 can be embedded in larger systems such as computers, electric bicycles or scooters, electric vehicles. Thus, these larger systems can be viewed as hosts to their implanted energy delivery systems and can rely on the up-to-date state of their supporting energy delivery systems for safe operation; and It may have other systems such as user interfaces or operator interfaces. In the case of electric vehicles, such a host system is a motor control system that can reduce the speed of the motor if the battery temperature exceeds some threshold or if the available energy drops below some threshold. it becomes possible to A digital communication link 1407, 1807 may be configured to deliver an instant description of the state of the energy delivery system 1400, 1800 upstream to the driving equipment.

According to embodiments of the present disclosure, the fuel gauges disclosed for the energy delivery system 1400, 1800 may be implemented as an integrated circuit, which may be in a separate package from the MCU 1404, 1804. However, its functionality can also be integrated within the MCU 1404,1804. The fuel gauge is configured to receive battery temperature and battery cell voltage information either by direct measurement or as packets of digital data from the AFE relayed to the fuel gauge by the MCU1404, 1804 and/or analog/digital configured as a coulomb counter that measures the analog voltage appearing across the current sense resistor and mathematically integrates these measurements continuously in either the digital or analog domain It may include a converter. This voltage developed across the sense resistor is a direct representation of the current flowing into or out of the battery cell stack, where a negative voltage is the current flowing out of the battery cell stack. (discharge), and a positive voltage represents the current (charge) flowing into the battery cell stack. By mathematically integrating these currents over time, the net charge change contained in the battery cell stack can be determined, and at any given time the net battery charge change and the known starting SOC The current SOC can be determined by adding Also, the fuel gauge is not just the sum of the net charge change and the current SOC, but the instantaneous current in the sense resistor, the average current in the sense resistor over some average time period (such as seconds or tens of seconds) Other parameters such as current, the total number of charge and discharge cycles (determined by the total charge passed in each direction starting from the date the battery cell stack was put into service), and the battery cell resistance can be measured using individual cells and/or The sum of all cells may be configured to include digital hardware and programmed instructions to compute.

According to embodiments of the present disclosure, the battery stacks disclosed for energy delivery systems 1400 and 1800 may include anti-backflow devices managed by a common control system. The function of such a backflow preventer is to prevent unwanted transfer of energy from one cell stack to another cell stack. The operation of such backflow preventers is described in PCT/US2017/068301.

According to alternative embodiments of the present disclosure, the variable impedance network may consist of several series-connected resistors and then associated switches connected in parallel. An energy delivery system constructed with such a variable impedance network provides the ability to manipulate the VI characteristic curves of separate battery stacks in a similar manner to reduce the discharge current between battery stacks or energy storage systems. Similar results can be achieved when biasing.

In yet another embodiment of the present disclosure, the variable impedance network is composed of parallel-connected resistors to provide finer resolution of the current-dependent voltage drop than series-connected resistors. obtain. The increased resolution in voltage steps can be used to further adjust the output voltage of the energy delivery system 1400,1800.

According to alternative embodiments of the present disclosure, one or more of the switchable diodes in any or all of the variable impedance networks may be replaced with a network of parallel switchable resistors. good. Under such a configuration, the control system may utilize the series diode for the "coarse" adjustment and the parallel resistor for the "fine" adjustment. Nevertheless, embodiments of the present disclosure may be implemented with one or more of variable impedance networks including switchable diodes, switchable resistors, or a combination of both.

Embodiments of the disclosure described herein find utility in uninterruptable power supply (“UPS”) systems and energy storage systems where high energy density is required to maximize volumetric energy storage. can do. They also require high cycle life, especially in repetitive deep discharge conditions. Energy storage systems may be configured to undergo a full charge/discharge cycle once a day. However, the depth of discharge of the system will change based on load demand. A low load demand will reduce the required energy delivered by the energy storage system, starving battery stacks designed for high cycle counts first before battery stacks designed for power density. Do not exhaust.

Embodiments of the present disclosure described herein are applicable to vehicle applications where long cycle life, long run time are prioritized, and where there is periodic demand for transient high current loads. .

As will be appreciated by those skilled in the art, aspects of the invention (eg, control systems 1404, 1804 and process 1700) may be embodied as systems, methods and/or program products. Thus, aspects of the present invention (eg, control system 1404, 1804, AFE, fuel gauge, variable impedance network) are entirely hardware embodiments, entirely software (including firmware, resident software, microcode, etc.). or software, which may all be referred to herein generally as a "circuit," "circuitry," "module," or "system." Embodiments may take the form of a combination of aspects and hardware aspects. Furthermore, aspects of the invention (eg, process 1700) may also take the form of a program product embodied in one or more computer-readable storage media having computer-readable program code embodied therein. (However, any combination of one or more computer readable media may be utilized, which may be a computer readable signal medium or a computer readable storage medium).

Also, each block in the circuit block diagram and/or function represented in process 1700, and combinations of blocks in the circuit block diagram and/or function represented in process 1700, may be dedicated hardware to perform the specified function or action. It will also be noted that it may be implemented by a hardware-based system, or a combination of dedicated hardware and computer instructions. For example, modules (eg, control systems 1404, 1804, AFEs, fuel gauges, variable impedance networks) may be custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, controllers, or other discrete components. It may be implemented as a hardware circuit comprising elements. Also, the modules (eg, control system 1404, 1804, AFE, fuel gauge, variable impedance network) may be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, or programmable logic devices. .

The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the specification. As used throughout this application, the word "may" has a permissive meaning (i.e., must) rather than a mandatory meaning (i.e., must That is, it is used in the sense of having the potential to. Similarly, the words "include," "including," "includes," "contain," "containing," and "contains" mean including, but are not limited to is not.

Various units, circuits, circuitry, or other components (e.g., control systems 1404, 1804, AFEs, fuel gauges, variable impedance networks) are "configured" to perform a task or tasks. configured)”. In such contexts, "configured to" generally means "having circuitry capable of" performing that task or tasks during operation. It is a broad description of the structure that is meant for the purpose. Thus, a unit/circuit/component can be configured to perform a task even if the unit/circuit/component is not currently turned on. Generally, circuitry forming structure corresponding to "configured to" may include hardware circuitry and/or software (including firmware, resident software, microcode, etc.). Similarly, various units/circuits/components may be described as performing a task or tasks for convenience of explanation. Such descriptions should be read to include the phrase "configured to". Note that listing a unit/circuit/component configured to perform one or more tasks does not invoke the interpretation of 35 U.S.C. §112, paragraph 6 for that unit/circuit/component. explicitly intended.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which the disclosed subject matter belongs. have

As used herein, the terms "about" and "approximately" refer to the endpoints of a numerical range even if a given value is "a little above the endpoints." )” or “a little below” is used to provide flexibility.

In the description herein, flowchart-style techniques may be described as a series of sequential actions. The order of actions, and the parties performing the actions, may be freely changed without departing from the scope of the teachings. Actions may be added, deleted, or modified in several ways. Similarly, actions may be reordered or looped. Further, while processes, methods, algorithms, or the like may be described in sequential order, such processes, methods, algorithms, or any combination thereof may be presented in an alternate order. It may be operable. Moreover, some actions within a process, method, or algorithm may occur concurrently, at least for some time (e.g., actions occurring in parallel may be wholly, partially, or any combination thereof).

Unless specified to the contrary, "or" indicates an inclusive or and not an exclusive or. For example, if the condition A or B is: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), A and B are both true (or present), satisfied by either one of

As used herein, the term "and/or", and the use of the character "/" between two words, when used in the context of listing entities, are present alone or in combination. Thus, for example, the phrase "A, B, C, and/or D" would not only include A, B, C, and D individually, but also A and , B, C, and D, including any and all combinations and subcombinations.

Also, use of "a" or "an" are employed to describe elements and resources described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural and vice versa unless it is obvious that it is meant otherwise. For example, when a single device is described herein, multiple devices may be used instead of a single device. Similarly, when more than one device is described herein, a single device may be substituted for that one device.

To the extent not set forth herein, many details regarding specific materials, processing acts, and circuits are conventional and are available in textbooks and other information within the computing, electronics, and software arts. can be found at the source.

600 system
602 control system
610a-610c Switchable Diode Circuit
621a to 621c control signals
702 Control System
710a-710d switches
750a-750d Switchable Resistive Elements, Resistors
1300 system
1301 Battery Stack
1302 Variable Impedance Network
1303 Analog front-end measurement equipment, AFE
1304 Control Systems, Microcontrollers, MCUs
1305 Sense Resistor (Rsense)
1306 Fuel Gauge Integrated Circuit, IC
1307 communication link or bus
1400 Energy Delivery System
1401a First battery cell stack
1401b Second battery cell stack
1402a, 1402b Variable Impedance Network
1403a, 1403b AFEs
1404 Common Control System, Microcontroller, MCU
1405a, 1405b Sense Resistor (Rsense)
1406a, 1406b Fuel Gauge Integrated Circuit, IC
1700 processed
1800 Energy Delivery System
1801a First battery cell stack
1801b Second battery cell stack
1802a, 1802b Variable Impedance Network
1803a, 1803b Analog Front End Measurement Equipment, AFE
1804 Common Control System, Microcontroller, MCU
1805a, 1805b sense resistor (Rsense)
1806a, 1806b fuel gauge integrated circuit, IC
1807 communication link or bus

Claims (20)

a first energy storage system;
a second energy storage system;
a first variable impedance network coupled between the first energy storage system and an output terminal, the first variable impedance network having a first adjustable impedance;
a second variable impedance network coupled between the second energy storage system and the output terminal, the second variable impedance network having a second adjustable impedance;
(1) the first variable impedance network to adjust the first adjustable impedance to change the level of the first current delivered by the first energy storage system to the output terminal; and (2) adjusting the second adjustable impedance to change the level of the second current delivered by the second energy storage system to the output terminal. and a control system configured to selectively signal a second variable impedance network. a plurality of switchable resistive resistors wherein the first variable impedance network is configured to adjust the effective resistance of the first variable impedance network over a predetermined range under control of the control system; 3. The energy delivery system of Claim 1, comprising an element. The first variable impedance network is configured to adjust, under control of the control system, over a predetermined range a number of forward diode voltage drops present within the first variable impedance network. 2. The energy delivery system of claim 1, comprising a plurality of switched switchable diodes. 2. The energy delivery system of claim 1, wherein said first energy storage system is substantially different than said second energy storage system. The first energy storage system is configured by a first VI characteristic curve, the second energy storage system is configured by a second VI characteristic curve, and the first VI characteristic curve is configured by the second VI characteristic curve. 5. The energy delivery system of claim 4, wherein the first VI characteristic curve crosses over the second VI characteristic curve at a given state of charge, unlike the VI characteristic curve of . The control system selects one of the first variable impedance network and the second variable impedance network to adjust where the first VI characteristic curve crosses over the second VI characteristic curve. 6. The energy delivery system of claim 5, wherein the energy delivery system is configured to signal at least one of the . The first energy storage system comprises a first battery cell stack of a plurality of battery cells each having a first chemical composition and the second energy storage system each having a second chemical composition. a second battery cell stack of a plurality of battery cells, wherein the first chemical composition is different than the second chemical composition, the first battery cell stack being responsive to the output terminal for the second battery cell stack; 5. The energy delivery system of claim 4, wherein the energy delivery system is coupled in parallel to a stack of battery cells. The first battery cell stack includes a first number of battery cells, the second battery cell stack includes a second number of battery cells, the first number equals the second number 8. The energy delivery system of claim 7, different from. wherein said first energy storage system is selected from a first group consisting of a chemical energy storage system, a kinetic energy storage system and a potential energy storage system, and said second energy storage system is selected from a chemical energy storage system, a kinetic energy storage system 5. The energy delivery system of claim 4, selected from the second group consisting of a storage system and a potential energy storage system. The first variable impedance network and the first variable impedance network are controlled such that the control system controls the relative proportions of current supplied to the output terminals by the first energy storage system and the second energy storage system. 6. The energy delivery system of claim 5, configured to signal at least one of two variable impedance networks. wherein the control system selectively activates the first variable impedance network and the second variable impedance network in response to parametric data collected from the first energy storage system and the second energy storage system; wherein the parametric data indicates the delivery of the first current by the first energy storage system and the delivery of the second current by the second energy storage system 8. The energy delivery system of claim 7, comprising measurements of voltage and current associated with . a first analog front end configured to measure a first voltage associated with the first energy storage system and communicate the first voltage to the control system;
a second analog front end configured to measure a second voltage associated with the second energy storage system and communicate the second voltage to the control system;
a first sense resistor coupled to the first energy storage system;
a first fuel gauge circuit coupled to the first sense resistor for determining first information in response to the first current sensed by the first sense resistor; a first fuel gauge circuit configured to communicate first information to the control system;
a second fuel gauge circuit coupled to a second sense resistor for determining second information in response to said second current sensed by said second sense resistor; a second fuel gauge circuit configured to communicate information of two to said control system;
The control system controls the first variable impedance network and the second variable impedance network in response to the first voltage, the second voltage, the first information, and the second information. configured to selectively signal to
11. The energy delivery system of Claim 1. A method for delivering energy to a load, comprising:
collecting first parametric data including voltage and current information relating to the supply of a first current to the load by a first energy storage system;
collecting second parametric data including voltage and current information relating to the supply of a second current to the load by a second energy storage system;
adjusting the first current with a first variable impedance network in response to the collected first parametric data and the collected second parametric data, wherein the first variable impedance a network is coupled between the first energy storage system and the load;
adjusting the second current by a second variable impedance network in response to the collected first parametric data and the collected second parametric data, wherein the second variable impedance A network is coupled between the second energy storage system and the load; the first energy storage system and the second energy storage system are coupled in parallel to the load; wherein one energy storage system has a different chemical composition or physical structure than said second energy storage system. The adjusting the first current is performed in response to a first control signal received from a control system that collected the first parametric data, and the adjusting the second current is performed in response to a first control signal. 14. The method of claim 13, performed in response to a second control signal received from the control system that also collected the second parametric data. said first variable impedance network comprising a plurality of switchable resistive elements configured to adjust the effective resistance of said first variable impedance network in response to said first control signal; said second variable impedance network comprising a plurality of switchable resistive elements configured to adjust the effective resistance of said second variable impedance network in response to said second control signal; 15. The method of claim 14. wherein the first variable impedance network is configured to adjust a number of forward diode voltage drops present within the first variable impedance network in response to the first control signal; of switchable diodes, wherein the second variable impedance network reduces a number of forward diode voltage drops present in the second variable impedance network in response to the second control signal. 15. The method of claim 14, comprising a plurality of switchable diodes configured to tune. The first energy storage system is configured by a first VI characteristic curve, the second energy storage system is configured by a second VI characteristic curve, and the first VI characteristic curve is configured by the second VI characteristic curve. , the first VI characteristic curve crosses over the second VI characteristic curve at a predetermined state of charge, and the control system detects that the first VI characteristic curve is different from the second VI characteristic curve. configured to signal at least one of said first variable impedance network and said second variable impedance network to adjust where the VI characteristic curve of The method described in 14. The first energy storage system comprises a first battery cell stack of a plurality of battery cells each having a first chemical composition and the second energy storage system each having a second chemical composition. 15. The method of claim 14, comprising a second battery cell stack of multiple battery cells, wherein the first chemical composition is different than the second chemical composition. wherein said first energy storage system is selected from a first group consisting of a chemical energy storage system, a kinetic energy storage system and a potential energy storage system, and said second energy storage system is selected from a chemical energy storage system, a kinetic energy storage system 15. The method of claim 14, selected from the second group consisting of a storage system and a potential energy storage system. The first variable impedance network and the second variable impedance network such that the control system controls the relative proportions of the currents supplied to the output terminals by the first current and the second current. 15. The method of claim 14, configured to signal at least one of the networks.

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