Energy storage system and method for improving battery performance

Abstract

The present invention relates to a battery system and method. Two or more batteries may be connected to an output device in the same configuration. The batteries may be controlled by a control unit or logic chip that can be configured to operate in two phases. In the first phase, two or more batteries may be connected in series. In the second phase, two or more batteries may be connected in parallel. Switches may be connected to the positive and negative terminals of the batteries to switch the configuration from series to parallel or vice versa. The control unit may switch between the two phases at any suitable frequency to generate the desired output voltage and amperage. The switching speed between the two phases may be any number of revolutions per second.

Description

[Technical field]

[0001] The present invention relates to an energy storage system and method for improving battery performance. [Background technology]

[0002] Series and parallel connections are commonly known in the electronics field. Each type of connection has its own type of advantages and disadvantages and is used in different applications. Multiple power supplies placed in series may have a higher voltage, but multiple power supplies placed in parallel will increase the amperage but not the voltage.

[0003] For example, the output of two 12V and 100Ah batteries connected in series may be 24V and 100Ah. In comparison, the output of the same two batteries connected in parallel may be 12V and 200Ah. Thus, if these batteries were powering a device, the device could be powered in series at twice the voltage (24V compared to 12V) or the device could be powered in parallel for twice as long (200Ah instead of 100Ah) at the same 12V voltage. Summary of the Invention [Problem to be solved by the invention]

[0004] Additionally, a typical battery or energy storage system may not be able to charge and discharge at the same time. Therefore, it may not be able to drive a load while receiving a charge. This can be problematic when using energy storage systems with renewable energy sources. These systems often require a central controller to control the charging and discharging of the system. [Means for solving the problem]

[0005] A battery system and method may be shown and described. Two or more batteries may be connected to an output device in the same configuration. The batteries may be controlled by a control unit or logic chip that may be configured to operate in two phases.

[0006] In the first phase, two or more batteries may be connected in series. The negative terminal of the first energy storage unit may be connected to the positive terminal of the second energy storage unit, and the positive terminal of the first energy storage unit may be connected to the negative terminal of the second energy storage unit as well as to the output device.

[0007] In the second phase, two or more batteries may be connected in parallel. The positive terminals of all the batteries may be connected together and the negative terminals may be connected together. The positive and negative terminals in the parallel connection may then be connected to an output source in the same parallel manner.

[0008] The control unit may then switch between the two phases at any suitable frequency to produce the desired output voltage and amperage. The switching speed between the two phases may be any number of revolutions per second. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1 illustrates an exemplary embodiment of an energy storage system. [Figure 1B] FIG. 1 illustrates an exemplary embodiment of an energy storage system. [Diagram 2] FIG. 1 illustrates an exemplary embodiment of an energy storage system. [Figure 3A] FIG. 2 illustrates an exemplary embodiment of an output current signal waveform. [Figure 3B] FIG. 2 illustrates an exemplary embodiment of an output voltage signal waveform. [Figure 4] FIG. 1 illustrates an exemplary embodiment of a method for implementing a switching circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Advantages of embodiments of the present invention will become apparent from the following detailed description of exemplary embodiments, which should be considered in conjunction with the accompanying drawings, in which like numerals refer to like elements and in which:

[0011] Aspects of the present invention are disclosed in the following description of specific embodiments of the present invention and in the associated drawings. Alternate embodiments may be devised without departing from the spirit or scope of the present invention. Furthermore, well-known elements of exemplary embodiments of the present invention will not be described in detail or will otherwise be omitted so as not to obscure the relevant details of the present invention. Furthermore, to facilitate understanding of the description, explanations of some terms used herein follow below.

[0012] As used herein, the term "exemplary" means "serving as an example, instance, or illustration." The embodiments described herein are not limiting, but rather are merely illustrative. It is to be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the terms "embodiments of the invention," "embodiments," or "invention" do not require that all embodiments of the invention include the described feature, advantage or mode of operation.

[0013] An electric circuit having the advantages of both series and parallel circuits is shown and described in the exemplary embodiments described herein. By quickly switching between series and parallel configurations, the circuit can output an average of the series and parallel outputs. The output of the switching circuit can be adjusted by adjusting the phase frequency or the time between switches. If the circuit is in a series configuration, a higher voltage can be obtained by increasing the time the circuit is in the first phase. Alternatively, if the circuit is in a parallel configuration, a higher amperage can be obtained by increasing the time the circuit is in the second phase. A higher voltage may be desired for a circuit powering a larger load, or a higher amperage may be desired to increase the time the load is powered from the battery. Since the circuit may power any of several types of loads, it may be desirable to change the voltage or amperage depending on the load.

[0014] Now, referring to the exemplary FIG. 1A, the switching circuit may be in a parallel configuration. The two energy storage units in this exemplary embodiment, the first battery 102 and the second battery 104, may be connected by a set of switches. In this exemplary embodiment, the batteries may be 12V and 100Ah wet-cell lead acid batteries, respectively. The positive and negative terminals of each battery may be connected to a switch. The switch 106 may be permanently connected to the positive terminal of the battery 104, or may be connected to the positive terminal of the battery 102 in a parallel phase. Thus, the switch 106 may have a node connecting the positive terminals of the batteries 102 and 104, and the positive terminal of the output device.

[0015] Continuing with reference to the parallel phase of the exemplary FIG. 1A , an additional switch 108 may be connected to the negative terminal of the battery 104. During the parallel phase, the switch 108 may be configured to connect to the negative terminal of the battery 102. Thus, there may be a node at the switch 108 connecting the negative terminals of the batteries 102 and 104. Additionally, an output device may be connected to the switches 110 and 112. In the parallel phase, the switch 110 may be configured to connect the output device 120 to the node created by the positive terminals of the batteries 102 and 104. At the same time, the switch 112 may be configured to connect the negative terminal of the output device 120 to the node created by the negative terminals of the batteries 102 and 104. Thus, the positive terminals of the batteries and the positive terminals of the output device may all be connected, and the negative terminals of the batteries and the negative terminals of the output device may also be connected to form a parallel circuit.

[0016] Still referring to the exemplary FIG. 1B, the circuit may be in a series configuration. The series configuration may be performed in a different phase than the parallel configuration. In the series configuration, the switches 106, 108, 110, and 112 may all be switched in the opposite direction to the previous phase. The switches may be connected to switch simultaneously. To form a series configuration, the switches 106 and 110 may directly connect the positive terminal of the battery 104 to the output device 120. The negative terminal of the battery 104 may be connected to the positive terminal of the battery 102 via the switch 108. The negative terminal of the battery 102 may be connected to the output device 120 via the switch 112. The switches may be any one of many types of switches or interrupters. The switches may switch or commutate simultaneously. The output signals (current and voltage) may differ depending on the commutation or switching time between the two phases.

[0017] 2, the electrical assembly may include an output device 122 that may be configured to connect to the circuit only during a series phase, and another output device 124 that may be configured to connect to the circuit only during a parallel phase. This may be accomplished using switches 114 and 116 that may be configured to switch simultaneously with the other switches.

[0018] 2, the secondary output device 124 may be disconnected from the circuit during the parallel phase. For example, if the output device 124 is an energy storage system that is being charged from the switching circuit 100, it may continue to operate normally during the parallel phase and only be charged in the series phase.

[0019] An exemplary embodiment for analysis, such as the embodiment of FIG. 2, may include one or more batteries having a nominal voltage value of Vn and a nominal current value of In. The load of the output device 122 during the parallel phase is Z parallel =(2*Vn) / In.

[0020] In an exemplary embodiment, t1 may be the time spent in the first parallel phase and t2 may be the time spent during the second serial phase. Furthermore, the time T may represent a period corresponding to the fundamental frequency, such that T=1 / fundamental frequency=t1+t2. If f(t) represents the input signal, the average value of the signal may be calculated using the following formula:

[0021]

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[0025]

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[0026] In the aforementioned exemplary embodiment, each cell may have a nominal current of 100A and a nominal voltage of 12V. The combined voltage when the circuit is in series may be 24V and the combined current when the circuit is in parallel may be 200A. As a result, when the circuit is switching between the first and second phases at equal speeds, i.e., when the time of the first phase is equal to the time of the second phase, the current average value may be 150A and the voltage average value may be 18V. In another exemplary embodiment, the time spent in the parallel phase (t1) and the time spent in the series phase (t2) may be modified so that they are not equal. For example, when t1 is two-thirds (2 / 3) of a cycle and the same nominal voltage and current are used, the current average value may be 166.666A and the voltage average value may be 16V. Alternatively, when t1 is one-third (1 / 3) of a cycle, the current average value may be 133.3333A and the current average voltage may be 20V. Any ratio of t1 and t2 may be used to obtain the desired results.

[0027] In further exemplary embodiments, the circuit may be regulated by a control unit that can change the frequency of the phases. The control unit can set the switching speed or switching time between the two phases. The switching time may be the length of time spent in each phase. The control unit may select the switching time based on the number of revolutions per second, or other time measurement. Any number of switches or revolutions per second may vary from 1 to infinity. The control unit may configure the circuit to be in one phase much longer than the other phase. The lengths of the phases may not be equal. By changing the relative percentage of time spent in the phases, the output signal can be changed. The control unit may also be set to initially keep the circuit in a particular state. For example, the control unit may be configured to start with the parallel phases until the energy storage unit is fully charged. The control unit may then begin a cycle of switching.

[0028] The battery may be connected to an energy source. The circuit may be configured to be connected in series during a first phase in which the battery is connected to a load and can be discharged. Then, during a second phase, the battery may be connected in parallel as well with an energy source that can charge the battery during this phase. Thus, the battery may be discharged during the first series phase and charged during the second parallel phase. During the first cycle, the battery may discharge a small amount of energy. Furthermore, during the second cycle, a similar small amount of energy may be charged to compensate for the energy lost during the first cycle. This may improve battery performance.

[0029] An energy source with a larger current output can be selected so that a larger amount of energy is charged to the battery during the parallel phase. In an exemplary embodiment, the amount of charge from the energy source during the parallel phase may exceed the amount of charge discharged by the load during the series phase, so that the battery can gain charge over time. When the battery reaches a certain level, it is considered to prevent the excess charge from reaching the battery in order to reduce the risk of overcharging. In another embodiment, an energy source can be selected that charges an amount of energy equal to the amount released during the series phase. In this another exemplary embodiment, the energy storage unit can always hold the same amount of charge.

[0030] Furthermore, by charging and discharging the battery during these short cycles, the circuit may have the effect of simultaneously charging and discharging the battery or energy storage system. A typical battery or circuit may not be able to charge and discharge simultaneously, but may instead use a central controller to manage the charge and discharge cycles. A typical energy source may be directly connected to a load or to an energy storage system, but not both. As a result, an energy source may be configured to either charge a battery or drive a load, but not both. Exemplary embodiments of the simultaneous series and parallel circuits described herein may be configured such that the energy source is connected to an energy storage system, and the energy storage system can drive a load simultaneously. The load may draw power from the battery during a first phase, and the energy storage system may be charged during a second phase.

[0031] The energy source may be any type or combination of energy sources. In exemplary embodiments, renewable energy sources may be used, although it is envisioned that other energy sources may be utilized as desired.

[0032] Now referring to exemplary FIG. 4, a method for implementing a switching circuit such as the circuit of FIG. 2 is shown. In a first step, a first phase may be initiated (400). A control unit may initiate the first phase by sending a signal to the switches. In a next step, the switches may be switched (402) such that the circuit is switched into a series configuration. The control unit may switch multiple switches simultaneously. The switches may be interconnected such that they are switched simultaneously. In a third step, an energy storage unit (ESU) may charge a load (404). The load may be a rechargeable power source.

[0033] In a fourth step, a second phase may be started (406). The control unit may be configured to start the second phase after a certain time depending on the length of the first phase. The first and second phases may have different durations. In a next step, a switch may be toggled (408). During this step, the switch may be switched to the opposite position to that in step 402. The switch may be switched such that the ESU and the load are connected in a parallel configuration. In a final step, the energy source may charge the ESU (410). In another embodiment, the ESU may continue to discharge during the second cycle in the parallel phase. In this exemplary embodiment, the control unit may configure the ESU to continue to discharge in order to be connected to the load during both phases. The energy source may be connected to a switch that connects the energy source to the circuit during the second phase and connects the load to the circuit during the first phase. This switch may also be controlled by the control unit and may be toggled simultaneously with the other switches. After a predetermined period of time, the first phase may begin again with step 400 and a new cycle may be started.

[0034] While the above examples may employ a switching circuit including two batteries, it is contemplated that the batteries may instead be any component that a user desires to be switched between series and parallel. Also, while the above examples use two batteries for clarity, any number of batteries may be interconnected in a similar manner. Additional batteries may be configured to operate in additional (more than two) phases. The output device may be any suitable output device, such as another battery, an energy storage system, or other electrically connected component capable of receiving an input.

[0035] In an exemplary embodiment, the switching circuit may be implemented in an electric vehicle. The switching circuit may be configured such that the electric vehicle is powered during one phase and disconnected and charged during the other phase. In an exemplary embodiment, the same amount of energy may be charged during the second phase as is discharged during the first phase. During the powered phase, the battery may consume additional energy to make up for the energy lost during the unpowered phase. However, the battery may be activated half the time (in one of the two phases, rather than at constant power), thus improving efficiency.

[0036] Additionally, switching circuits allow multiple energy sources to be used simultaneously: for example, an electric vehicle powered by photovoltaic cells may be charged using alternative energy sources (wind, gas, etc.) during intermittent sunlight.

[0037] The above description and accompanying figures illustrate the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as limited to the particular embodiments described above. Additional variations of the above embodiments will be apparent to those skilled in the art.

[0038] Thus, the above-described embodiments should be considered as illustrative rather than restrictive, and it should be understood that modifications to these embodiments could be made by one skilled in the art without departing from the scope of the invention as defined by the following claims.

Claims

1. a first energy storage unit having a positive terminal and a negative terminal; a second energy storage unit having a positive terminal and a negative terminal; a series configuration output device and a parallel configuration output device; a control unit for regulating a cycle including a first phase and a second phase, During the first phase, a negative terminal of the first energy storage unit is connected to a positive terminal of the second energy storage unit, while a positive terminal of the first energy storage unit and a negative terminal of the second energy storage unit are connected to the series configuration output device, thereby connecting the first energy storage unit, the second energy storage unit, and the series configuration output device in series; a control unit, during the second phase, a positive terminal of the first energy storage unit is connected to a positive terminal of the second energy storage unit, while a negative terminal of the first energy storage unit is connected to a negative terminal of the second energy storage unit, both positive terminals are connected to the parallel configuration output device, and both negative terminals are connected to the parallel configuration output device, thereby connecting the first energy storage unit, the second energy storage unit, and the parallel configuration output device in parallel; a plurality of switches connected to positive and negative terminals of the energy storage unit, the plurality of switches thereby capable of configuring a circuit in a series configuration during the first phase and then in a parallel configuration during the second phase; Equipped with the control unit sets the relative duration of the first phase and the relative duration of the second phase, whereby the first phase comprises 0% to 100% of the duration of the cycle and the second phase comprises the remainder of the cycle, thereby varying the relative durations of the series configuration output device and the parallel configuration output device; an output of an output terminal is determined as a weighted average between a serial output and a parallel output, the weighted average being weighted based on the relative duration of the first phase and the relative duration of the second phase. Battery connection system in an electrical circuit.

2. The system of claim 1 , wherein the energy storage unit is an electrical storage device capable of accepting an electrical charge.

3. The system of claim 1 , wherein the first energy storage unit and the second energy storage unit each comprise a plurality of batteries.

4. The system of claim 1 , wherein a duration of the first phase is equal to a duration of the second phase.

5. a rechargeable power source connected to the output terminals; 2. The system of claim 1, wherein during the second phase, the control unit further connects the positive terminals of the first and second energy storage units to the positive terminal of the rechargeable power source and connects the negative terminals of the first and second energy storage units to the negative terminal of the rechargeable power source, such that the rechargeable power source is connected to the circuit using a parallel connection and receives charge from the circuit.

6. The system of claim 1 , wherein the plurality of switches are connected together so as to all operate simultaneously.

7. The system of claim 1 , wherein the control unit controls the plurality of switches.

8. 6. The system of claim 5, wherein during the first phase, the rechargeable power source is configured to be disconnected from the circuit and to drive a load instead.

9. 9. The system of claim 8, wherein during the first phase, a loss of energy occurs from the first energy storage unit and the second energy storage unit to the load, and then during the second phase, a recharge occurs from the electrical circuit to the first energy storage unit and the second energy storage unit.

10. The system of claim 1 , wherein the control unit operates at more than one cycle per second.

11. a first energy storage unit having a positive terminal and a negative terminal; a second energy storage unit having a positive terminal and a negative terminal; a series configuration output device and a parallel configuration output device; An output terminal; a plurality of switches connected to terminals of the energy storage unit and to the output terminal; a control unit that controls the plurality of switches to regulate a cycle including a first phase and a second phase, During the first phase, a negative terminal of the first energy storage unit is connected to a positive terminal of the second energy storage unit, while a positive terminal of the first energy storage unit and a negative terminal of the second energy storage unit are connected to the output terminal, thereby connecting the first energy storage unit, the second energy storage unit, and the output terminal in series; a control unit, during the second phase, a positive terminal of the first energy storage unit is connected to a positive terminal of the second energy storage unit, while a negative terminal of the first energy storage unit is connected to a negative terminal of the second energy storage unit, both positive terminals are connected to the output terminal, and both negative terminals are connected to the output terminal, thereby connecting the first energy storage unit, the second energy storage unit, and the output terminal in parallel; Equipped with the plurality of switches are connected to positive and negative terminals of the energy storage unit to configure the circuit in a series configuration during the first phase and then in a parallel configuration during the second phase; the control unit varies the relative duration of the first phase and the relative duration of the second phase, such that the first phase comprises 0% to 100% of the duration of the cycle and the second phase comprises the remainder of the cycle, thereby varying the relative durations of the series configuration output device and the parallel configuration output device; an output of the output terminals is determined as a weighted average between a series output and a parallel output, the weighted average being weighted based on the relative duration of the first phase and the relative duration of the second phase.

12. The circuit of claim 11 , wherein the multiple switches are interconnected to be switched or change position simultaneously.

13. 12. The circuit of claim 11, wherein the output terminal further comprises a switch for switching between two or more output devices per phase.

14. The circuit of claim 11 , wherein the control unit varies the duration of the first phase and the second phase to produce a particular output voltage and current.

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