Distributed stacked energy storage system

Abstract

The utility model provides a distributed stacked energy storage system, which comprises a solid-state battery module, a power module, a PCS module and an energy management and control module, the energy management and control module is responsible for driving, protection and temperature control of the system, the power module is used for realizing maximum power output for converting light energy into electric energy, and the solid-state battery module is used for storing and releasing the electric energy. The PCS module is used for realizing bidirectional energy conversion between the battery pack and a power grid; the output end of the energy management and control module is connected with the input end of the power module, the output end of the power module and the output end of the solid-state battery module are connected with the input end of the PCS module, and the input end of the solid-state battery module is connected with a power grid. Power output expansion is realized through parallel connection of the power modules while maximum power point output is guaranteed; the output voltage of the battery in each solid-state battery module is consistent with the voltage of the direct-current bus, so that parallel series flow can be avoided, and the efficient utilization of the battery is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage systems, and in particular to a distributed stacked energy storage system. Background Art

[0002] At the current stage of development of energy storage technology, stacked energy storage systems are mainly limited to simple single battery module stacking. Although this stacking method can improve the energy storage capacity to a certain extent, it inevitably brings about the circulation problem when the battery pack is connected in parallel, and the resulting uneven temperature rise of the battery. These problems not only make it difficult for the battery pack to reach a full charge state during charging, but also difficult to fully release the electrical energy during discharge, which in turn affects the overall efficiency of the energy storage system.

[0003] At the same time, due to technical limitations and cost considerations, batteries of different models and capacities are often used in parallel. Although this practice seems to improve the flexibility of the energy storage system in the short term, it actually buries hidden dangers. Because when batteries of different models and capacities are used in parallel, it is more likely to produce circulation, resulting in differences in the depth of discharge (DOD) of the parallel batteries. This will not only affect the overall performance of the battery pack, but will also further aggravate the attenuation of the battery life, bringing great challenges to the long-term stable operation of the energy storage system.

[0004] More importantly, due to the temperature difference and circulation between batteries, the cycle life of the battery is greatly shortened, which is extremely unfavorable for the long-term stable operation of the energy storage system. In addition, the existing stacked energy storage system also shows a lack of flexibility in overall scheduling, making it difficult to quickly and accurately allocate energy according to actual needs.

[0005] In summary, the current stacked energy storage system still needs to be further optimized and improved in design and technology, especially in solving the problems caused by the circulation of parallel batteries, temperature rise differences, insufficient scheduling flexibility, and the parallel use of batteries of different models and capacities. More research and innovation are needed. Utility Model Content

[0006] In order to overcome the shortcomings of the prior art, the present application provides a distributed stacked energy storage system, which realizes the expansion of system power and energy storage, manages the battery pack's charging and discharging individually while ensuring the maximum power point, avoids circulation phenomenon, and extends the battery pack's service life.

[0007] The technical solution adopted by the utility model to solve its technical problems is: a distributed stacked energy storage system, which is improved in that it includes: a solid-state battery module, a power module, a PCS module, and an energy management and control module. The energy management and control module is responsible for the drive, protection and temperature control of the system, the power module is used to achieve the maximum power output of light energy conversion into electrical energy, the solid-state battery module is used to store and release electrical energy, and the PCS module is used to achieve bidirectional energy conversion between the battery pack and the power grid; the output end of the energy management and control module is connected to the input end of the power module, the output end of the power module and the output end of the solid-state battery module are respectively connected to the input end of the PCS module, and the input end of the solid-state battery module is connected to the power grid.

[0008] The solid-state battery module in the above technical solution includes a solid-state battery pack, a bidirectional DC-DC circuit and a voltage-current dual closed-loop circuit. The bidirectional DC-DC circuit includes an inductor L1, a capacitor C1, a resistor R1, a current sensor A1, a voltage sensor A2, a MOS tube Q1 and a MOS tube Q2, wherein; the inductor L1 is connected in series with the capacitor C1 and then connected to the positive and negative electrodes of the battery pack, one end of the inductor L1 is also connected to the in-phase input end of the current sensor A1, and the output end of the current sensor A1 is connected to the voltage-current dual closed-loop circuit. The inverting input end of the current sensor A1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the drain of the MOS tube Q1 and the source of the MOS tube Q2, the source of the MOS tube Q1 is connected to one end of the capacitor C1 and the inverting input end of the voltage sensor A2, the gate of the MOS tube Q1 is connected to the first output end of the voltage-current dual closed-loop circuit; the drain of the MOS tube Q2 is connected to the non-inverting input end of the voltage sensor A2, and the gate of the MOS tube Q2 is connected to the second output end of the voltage-current dual closed-loop circuit.

[0009] The voltage-current dual closed-loop circuit in the above technical solution includes a first PID controller, a second PID controller, and a pulse modulation generator; the input of the first PID controller is the voltage value output by the bidirectional DC-DC circuit and the AC power, and the current value modulated by the first PID controller and the output of the bidirectional DC-DC circuit is used as the input of the second PID controller, the output end of the second PID controller is connected to the pulse modulation generator, and outputs a first modulation signal PWM1 and a second adjustment signal PWM2, the first modulation signal PWM1 is connected to the gate of the MOS tube Q1, and is used to modulate the current in the bidirectional DC-DC circuit, and the second modulation signal PWM2 is connected to the gate of the MOS tube Q2, and is used to adjust the voltage in the bidirectional DC-DC circuit.

[0010] The power module in the above technical solution includes an MPPT unit and a boost circuit. The maximum power point of the power module is tracked and found through the MPPT unit, and the boost circuit is used to realize voltage disturbance during the tracking process.

[0011] The MPPT unit in the above technical solution tracks and finds the maximum power point of the power module, including the following steps: calculating the current power value of the power module; performing voltage disturbance through the boost circuit, and comparing the power value after the disturbance with the current power value; if the power value after the disturbance is greater than the current power value before the disturbance, it indicates that the disturbance direction is correct, and then continue to disturb in the same direction; if the power value after the disturbance is less than the current power value before the disturbance, then continue to disturb in the opposite direction.

[0012] The boost circuit in the above technical solution includes an inductor L2, an inductor L3, a capacitor C2, a capacitor C3, a resistor R2, a resistor R3, a MOS tube Q3 and a diode D1; the inductor L2 is connected in series with the capacitor C2 and then connected to the positive and negative electrodes of the battery pack, the collector of the MOS tube Q3 is connected to one end of the inductor and the positive electrode of the battery pack, the emitter of the MOS tube Q3 is connected to the capacitor C2 and the negative electrode of the battery pack, the resistor R3 is connected in parallel with the diode D1 and then connected to the collector of the MOS tube Q3, and the other end is connected to one end of the inductor L3, the other end of the inductor L3 is connected to the capacitor C3, and the other end of the capacitor C3 is connected to the emitter of the MOS tube Q3.

[0013] The PCS module in the above technical solution includes a bidirectional DC-AC circuit, which realizes bidirectional energy conversion between the battery pack and the power grid and has the characteristics of a grid-connected inverter.

[0014] The beneficial effects of the utility model are as follows: the modules inside the system are independent of each other, thus realizing the expansion of system power and energy storage, while ensuring the maximum power point, the battery pack is individually charged and discharged, thus avoiding the circulation phenomenon and extending the service life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A structural block diagram of a distributed stacked energy storage system provided by the utility model;

[0016] Figure 2 A schematic diagram of a solid-state battery module provided by the utility model;

[0017] Figure 3 A voltage and current double closed loop circuit schematic diagram provided by the utility model;

[0018] Figure 4 A logic step flow chart of an MPPT unit provided by the utility model;

[0019] Figure 5 A schematic diagram of a power module provided by the utility model. DETAILED DESCRIPTION

[0020] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0021] The following will clearly and completely describe the concept, specific structure and technical effects of the utility model in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the utility model. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the utility model can be combined interchangeably without conflicting with each other.

[0022] As mentioned above, in traditional system designs, batteries of different models and capacities are used in parallel, which results in circulating currents. This causes different depths of discharge (DOD) of the parallel batteries, which affects the battery life. Depth of discharge (DoD) refers to the ratio of the discharge amount to the total capacity of the battery during use. Specifically, it indicates the percentage of the battery's discharged capacity to the rated capacity. For example, if a battery's DoD value is 50%, it means that the battery has discharged half of its total capacity. Too deep a depth of discharge (i.e., a higher DoD value) may cause battery damage or reduce battery life.

[0023] At the same time, when installing and expanding the battery pack, battery packs of the same batch specifications are required. When expanding the capacity later, the battery packs need to be completely replaced and the old batteries cannot be effectively used. After the battery pack is expanded, the light energy conversion efficiency cannot match the system capacity, which can easily cause waste of light energy.

[0024] In order to solve the deficiencies in the prior art, such as Figure 1 As shown, the utility model provides a distributed stacked energy storage system, including a solid-state battery module 1, a power module 2, a PCS module 3, and an energy management module 4. The energy management module 4 is responsible for the drive, protection and temperature control of the system. The power module 2 is used to achieve the maximum power output of light energy conversion into electrical energy. The solid-state battery module 1 is used to store and release electrical energy. The PCS module 3 is used to achieve bidirectional energy conversion between the battery pack and the power grid.

[0025] Among them, the output end of the energy management module 4 is connected to the input end of the power module 2, the output end of the power module 2 and the output end of the solid-state battery module 1 are respectively connected to the input end of the PCS module 3, and the input end of the solid-state battery module 1 is connected to the power grid.

[0026] In a possible implementation, the energy control module 4 can also monitor the operating status and operating mode of the PCS module 3 and other devices in real time, and can display historical data such as charging and discharging power curves and SOC conversion curves. When events such as energy storage charging and discharging exceeding the limit, temperature exceeding the limit, equipment failure or communication failure occur, the system can also issue a real-time alarm.

[0027] Through the above embodiments, while ensuring the maximum power output, the parallel connection of power modules can achieve power output expansion; the battery output voltage in each solid-state battery module is consistent with the DC bus voltage, which can avoid parallel flow and achieve efficient use of batteries; it can also achieve parallel expansion of batteries of different specifications, improve the battery use range, and achieve flexible expansion; the modules within the system are independent of each other, realizing the expansion of system power and energy storage.

[0028] In one possible implementation, Figure 2 As shown, the solid-state battery module 1 includes a solid-state battery pack, a bidirectional DC-DC circuit, and a voltage-current dual closed-loop circuit.

[0029] In an exemplary embodiment, the bidirectional DC-DC circuit includes an inductor L1, a capacitor C1, a resistor R1, a current sensor A1, a voltage sensor A2, a MOS transistor Q1 and a MOS transistor Q2, wherein;

[0030] The inductor L1 is connected in series with the capacitor C1 and then connected to the positive and negative electrodes of the battery pack. One end of the inductor L1 is also connected to the non-inverting input end of the current sensor A1. The output end of the current sensor A1 is connected to the input end of the voltage-current dual closed-loop circuit. The inverting input end of the current sensor A1 is connected to one end of the resistor R1. The other end of the resistor R1 is connected to the drain of the MOS tube Q1 and the source of the MOS tube Q2. The source of the MOS tube Q1 is connected to one end of the capacitor C1 and the inverting input end of the voltage sensor A2. The gate of the MOS tube Q1 is connected to the first output end of the voltage-current dual closed-loop circuit; the drain of the MOS tube Q2 is connected to the non-inverting input end of the voltage sensor A2, and the gate of the MOS tube Q2 is connected to the second output end of the voltage-current dual closed-loop circuit.

[0031] In an exemplary embodiment, if Figure 3 As shown, the voltage-current dual closed-loop circuit includes a first PID controller, a second PID controller, and a pulse modulation generator, wherein;

[0032] The input of the first PID controller is the voltage value output by the bidirectional DC-DC circuit and the 380V AC power supply. The current value modulated by the first PID controller and the output of the bidirectional DC-DC circuit serves as the input of the second PID controller. The output end of the second PID controller is connected to the pulse modulation generator, and outputs a first modulation signal PWM1 and a second adjustment signal PWM2. The first modulation signal PWM1 is connected to the gate of the MOS tube Q1 for modulating the current in the bidirectional DC-DC circuit. The second modulation signal PWM2 is connected to the gate of the MOS tube Q2 for adjusting the voltage in the bidirectional DC-DC circuit.

[0033] In a possible implementation, the power module 2 includes an MPPT unit and a boost circuit. The MPPT unit is used to track and find the maximum power point of the power module. The boost circuit is used to achieve voltage disturbance during the tracking process.

[0034] In an exemplary embodiment, if Figure 4 As shown, the MPPT unit tracks and finds the maximum power point of the power module, including the following steps:

[0035] Calculating the current power value of the power module;

[0036] Performing voltage disturbance through the boost circuit, and comparing the power value after the disturbance with the current power value;

[0037] If the power value after the disturbance is greater than the current power value before the disturbance, it means that the disturbance direction is correct, and the disturbance will continue in the same direction;

[0038] If the power value after disturbance is less than the current power value before disturbance, continue to disturb in the opposite direction.

[0039] In an exemplary embodiment, if Figure 5 As shown, the boost circuit includes an inductor L2, an inductor L3, a capacitor C2, a capacitor C3, a resistor R2, a resistor R3, a MOS tube Q3 and a diode D1;

[0040] The inductor L2 is connected in series with the capacitor C2 and then connected to the positive and negative electrodes of the battery pack. The collector of the MOS tube Q3 is connected to one end of the inductor and the positive electrode of the battery pack. The emitter of the MOS tube Q3 is connected to the capacitor C2 and the negative electrode of the battery pack. The resistor R3 is connected in parallel with the diode D1 and then connected to the collector of the MOS tube Q3. The other end of the resistor R3 is connected to one end of the inductor L3. The other end of the inductor L3 is connected to the capacitor C3. The other end of the capacitor C3 is connected to the emitter of the MOS tube Q3.

[0041] According to the above embodiments, the maximum power point of the power module is tracked and found through the MPPT unit, and the boost circuit is used to achieve voltage disturbance during the tracking process, thereby achieving maximum power output.

[0042] In a possible implementation, the PCS module 3 includes a bidirectional DC-AC circuit to achieve bidirectional energy conversion between the battery pack and the power grid, and has the characteristics of a grid-connected inverter.

[0043] Through the above embodiments, the utility model ensures that the maximum power point output is achieved while the parallel connection of power modules realizes power output expansion; the battery output voltage in each solid-state battery module is consistent with the DC bus voltage, which can avoid parallel flow and realize efficient use of batteries; it can also realize parallel expansion of batteries of different specifications, improve the battery use range, and achieve flexible expansion; the modules within the system are independent of each other, realizing the expansion of system power and energy storage.

[0044] The above is a specific description of the preferred implementation of the utility model, but the invention of the utility model is not limited to the described embodiments. Technical personnel familiar with the field can also make various equivalent deformations or substitutions without violating the spirit of the utility model. These equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A distributed stacked energy storage system, characterized in that: It includes a solid-state battery module, a power module, a PCS module, and an energy management module. The energy management module is responsible for the drive, protection, and temperature control of the system. The power module is used to achieve the maximum power output of light energy conversion into electrical energy. The solid-state battery module is used to store and release electrical energy. The PCS module is used to achieve bidirectional energy conversion between the battery pack and the power grid. The output end of the energy management module is connected to the input end of the power module. The output end of the power module and the output end of the solid-state battery module are respectively connected to the input end of the PCS module. The input end of the solid-state battery module is connected to the power grid. The solid-state battery module includes a solid-state battery pack, a bidirectional DC-DC circuit and a voltage-current dual closed-loop circuit. The bidirectional DC-DC circuit includes an inductor L1, a capacitor C1, a resistor R1, a current sensor A1, a voltage sensor A2, a MOS tube Q1 and a MOS tube Q2, wherein; The inductor L1 is connected in series with the capacitor C1 and then connected to the positive and negative electrodes of the battery pack. One end of the inductor L1 is also connected to the non-inverting input end of the current sensor A1. The output end of the current sensor A1 is connected to the input end of the voltage-current dual closed-loop circuit. The inverting input end of the current sensor A1 is connected to one end of the resistor R1. The other end of the resistor R1 is connected to the drain of the MOS tube Q1 and the source of the MOS tube Q2. The source of the MOS tube Q1 is connected to one end of the capacitor C1 and the inverting input end of the voltage sensor A2. The gate of the MOS tube Q1 is connected to the first output end of the voltage-current dual closed-loop circuit. The drain of the MOS tube Q2 is connected to the non-inverting input end of the voltage sensor A2. The gate of the MOS tube Q2 is connected to the second output end of the voltage-current dual closed-loop circuit. The power module includes an MPPT unit and a boost circuit, the MPPT unit is used to track and find the maximum power point of the power module, and the boost circuit is used to realize voltage disturbance during the tracking process; The PCS module includes a bidirectional DC-AC circuit to achieve bidirectional energy conversion between the battery pack and the power grid, and has the characteristics of a grid-connected inverter.

2. The distributed stacked energy storage system according to claim 1, characterized in that: The voltage-current dual closed-loop circuit includes a first PID controller, a second PID controller, and a pulse modulation generator; The input of the first PID controller is the voltage value output by the bidirectional DC-DC circuit and the AC power. The current value modulated by the first PID controller and the output of the bidirectional DC-DC circuit serves as the input of the second PID controller. The output end of the second PID controller is connected to the pulse modulation generator, and outputs a first modulation signal PWM1 and a second modulation signal PWM2. The first modulation signal PWM1 is connected to the gate of the MOS tube Q1 for modulating the current in the bidirectional DC-DC circuit. The second modulation signal PWM2 is connected to the gate of the MOS tube Q2 for adjusting the voltage in the bidirectional DC-DC circuit.

3. The distributed stacked energy storage system according to claim 1, characterized in that: The boost circuit includes an inductor L2, an inductor L3, a capacitor C2, a capacitor C3, a resistor R2, a resistor R3, a MOS tube Q3 and a diode D1; The inductor L2 is connected in series with the capacitor C2 and then connected to the positive and negative electrodes of the battery pack. The collector of the MOS tube Q3 is connected to one end of the inductor and the positive electrode of the battery pack. The emitter of the MOS tube Q3 is connected to the capacitor C2 and the negative electrode of the battery pack. The resistor R3 is connected in parallel with the diode D1 and then connected to the collector of the MOS tube Q3. The other end of the resistor R3 is connected to one end of the inductor L3. The other end of the inductor L3 is connected to the capacitor C3. The other end of the capacitor C3 is connected to the emitter of the MOS tube Q3.

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