Energy storage module, power supply system and control method of energy storage module

Abstract

The application discloses an energy storage module, a power supply system and a control method of the energy storage module. The energy storage module comprises a bidirectional DC / DC converter and an energy storage unit. The first end of the bidirectional DC / DC converter is connected with the energy storage unit. The control method of the energy storage module comprises the following steps: according to a current sharing bus signal provided by a power module connected with the second end of the bidirectional DC / DC converter, the working mode of the energy storage module is controlled, wherein the energy storage module is used for compensating input current fluctuation of the power module.

Description

Technical Field

[0001] This invention relates to the field of power supply, and in particular to an energy storage module, a power supply system, and a control method for the energy storage module. Background Technology

[0002] In server power supply applications, the common architecture of a power supply unit (PSU) is a two-stage topology: the front stage is a power factor correction circuit (PFC), and the back stage is a DC / DC converter.

[0003] With the development of AI (artificial intelligence) and high-performance computing, the power consumption of components such as graphics processing units (GPUs) and central processing units (CPUs) in servers is constantly increasing. As the demand for high-performance computing grows, server power supply systems need to cope with higher power requirements, greater heat dissipation pressure, and more stable voltage control requirements, and require more intelligent power management systems to ensure stable operation.

[0004] Because AI (artificial intelligence) loads often experience significant fluctuations, the server power output can vary, resulting in inconsistent AC input waveforms and unnecessary noise on the power grid, which can affect the quality of the input power grid.

[0005] Therefore, how to design an energy storage module, a power supply system, and a control method for the energy storage module so that it can achieve peak shaving and valley filling when the load of the power module changes significantly, and avoid the input current of the power module changing rapidly, is an important research topic of the inventors. Summary of the Invention

[0006] One objective of this invention is to provide a control method for an energy storage module, thereby solving the problems of the prior art.

[0007] To achieve the aforementioned objective, the present invention proposes a control method for an energy storage module, wherein the energy storage module includes a bidirectional DC / DC converter and an energy storage unit, and the first end of the bidirectional DC / DC converter is connected to the energy storage unit. The method is characterized by comprising: controlling the operating mode of the energy storage module according to a current sharing bus signal provided by a power module connected to the second end of the bidirectional DC / DC converter, wherein the energy storage module is used to compensate for input current fluctuations in the power module.

[0008] In one embodiment, the control method further includes: after the energy storage module is connected to the power module, controlling the energy storage module to enter a pre-charging mode to pre-charge the energy storage unit; when the voltage of the energy storage unit is charged to a preset value, controlling the energy storage module to enter a standby power mode; in the standby power mode, controlling the energy storage unit to charge or discharge to the power module according to the current sharing bus signal.

[0009] In one embodiment, the control method further includes: acquiring a current sharing bus signal to obtain a current sharing bus sampling signal, and controlling the operating mode of the energy storage module based on the difference between the reference signal and the current sharing bus sampling signal.

[0010] In one embodiment, the control method further includes: generating a current reference signal corresponding to the bidirectional DC / DC converter based on the difference between the reference signal and the current sharing bus sampling signal, and controlling the operating mode of the energy storage module based on the current reference signal and the inductor current of the bidirectional DC / DC converter.

[0011] In one embodiment, the control method further includes: in the pre-charge mode, setting the reference signal to k times the rated value of the current sharing bus signal, where k is less than 1, and the rated value of the current sharing bus signal characterizes the output current when the power module outputs rated power.

[0012] In one embodiment, the control method further includes: in standby mode, a reference signal characterizing the average power of the power module.

[0013] In one embodiment, the control method further includes: in pre-charging mode, controlling the current of the power module to charge the energy storage unit to not exceed a predetermined current limit value.

[0014] In one embodiment, the predetermined flow limit value is a fixed value.

[0015] In one embodiment, the predetermined current limiting value is a fixed first current limiting value in the first pre-charging phase and a value related to the power value of the power module charging the energy storage unit and / or the voltage of the energy storage unit in the second pre-charging phase.

[0016] In one embodiment, the control method further includes: when the voltage of the energy storage unit is less than a first voltage threshold, controlling the energy storage module to enter a first pre-charging stage, and controlling the current of the power module charging the energy storage unit to not exceed a first current limit value during the first pre-charging stage.

[0017] In one embodiment, the control method further includes: when the voltage of the energy storage unit reaches a first voltage threshold, controlling the energy storage module to enter a second pre-charging stage, and controlling the current of the power module charging the energy storage unit during the second pre-charging stage not to exceed the ratio of the first power threshold to the voltage of the energy storage unit.

[0018] In one embodiment, when entering the second pre-charging phase, the first power threshold is controlled to gradually increase from the power value at which the power module charges the energy storage unit at the end of the first pre-charging phase to the maximum power limit.

[0019] In one embodiment, when the power value of the power module charging the energy storage unit reaches the maximum power limit, the energy storage unit is charged at the maximum power limit until the voltage of the energy storage unit reaches the third voltage threshold. Then, the first power threshold is controlled to gradually decrease from the maximum power limit until the voltage of the energy storage unit reaches the preset value, thereby gradually exiting the pre-charging mode.

[0020] In one embodiment, the control method further includes: in standby mode, when the current sharing bus sampling signal is greater than the reference signal, controlling the energy storage unit to operate in discharge mode so that the energy storage unit releases energy to the load; when the current sharing bus sampling signal is less than the reference signal, controlling the energy storage unit to operate in charging mode so that the power module stores energy in the energy storage unit.

[0021] Another objective of this invention is to provide an energy storage module that addresses the problems of the prior art.

[0022] To achieve the aforementioned objectives, the energy storage module proposed in this invention includes a bidirectional DC / DC converter and an energy storage unit. A first terminal of the bidirectional DC / DC converter is connected to the energy storage unit, and a second terminal of the bidirectional DC / DC converter is connected to the output terminal of the power module. Each energy storage module also includes a controller configured to employ the aforementioned control method.

[0023] Another object of the present invention is to provide a power supply system that solves the problems of the prior art.

[0024] To achieve the aforementioned objectives, the power supply system proposed in this invention includes at least one power module and at least one energy storage module. The output terminal of each power module is connected to a load, wherein each power module converts its output current into a voltage signal and transmits it to a current-sharing bus. The output terminal of each energy storage module is connected, and each energy storage module includes a bidirectional DC / DC converter and an energy storage unit. A first terminal of the bidirectional DC / DC converter is connected to the energy storage unit, and a second terminal of the bidirectional DC / DC converter is connected to the output terminal of the power module. Each energy storage module also includes a controller configured to employ the aforementioned control method, wherein the voltage signal on the current-sharing bus is a current-sharing bus signal.

[0025] In one embodiment, the at least one power module is housed in the same housing.

[0026] In one embodiment, the at least one energy storage module is housed in the same housing.

[0027] Through the proposed control method and power supply system for the energy storage module, this invention has the following features and advantages: 1. By providing or receiving current through the energy storage module, the output current of the power supply module does not need to increase or decrease rapidly in a short period of time, thus maintaining a constant input current and reducing the impact on the power grid; 2. Preventing the power supply module from being overloaded during the pre-charging process of the energy storage unit; 3. Preventing the input current of the power supply module from jumping during the pre-charging process of the energy storage unit; 4. Maintaining the normal service life of the energy storage unit during the pre-charging process.

[0028] To gain a deeper understanding of the techniques, means, and effects employed by this invention to achieve its intended purpose, please refer to the following detailed description and accompanying drawings. It is believed that the purpose, features, and characteristics of this invention can be understood in a thorough and specific manner from these drawings. However, the drawings are provided for reference and illustration only and are not intended to limit the scope of this invention. Attached Figure Description

[0029] Figure 1 : This is a circuit block diagram of the power supply system of the power module combined with the energy storage module of the present invention;

[0030] Figure 2 : This is a circuit diagram of the energy storage module of the present invention;

[0031] Figure 3 This is a schematic block diagram of the single power supply module and the single energy storage module of the present invention.

[0032] Figure 4 This is a schematic block diagram of multiple power supply modules and multiple energy storage modules of the present invention;

[0033] Figure 5 : Block diagram of the control loop for pre-charging the energy storage unit of the present invention;

[0034] Figure 6 : This is a waveform diagram showing the pre-charging process of the energy storage unit of the present invention;

[0035] Figure 7 : This is a flowchart of the control method for the energy storage module of the present invention;

[0036] Figure 8 : This is a flowchart detailing the control method for the energy storage module of the present invention;

[0037] Explanation of reference numerals in the attached figures:

[0038] 10: Power supply module;

[0039] 10-1, 10-2: Power supply modules;

[0040] 20: Energy storage module;

[0041] 20-1, 20-2: Energy storage modules;

[0042] 11: Power factor correction circuit;

[0043] 12: DC / DC converter;

[0044] 21: Bidirectional DC / DC converter;

[0045] 22: Energy storage unit;

[0046] L1: Inductance;

[0047] S1: First switching transistor;

[0048] S2: Second switching transistor;

[0049] C1: Capacitor;

[0050] C2: Energy storage capacitor;

[0051] V_ishare: Current sharing bus signal;

[0052] 50: Load;

[0053] Vc: Voltage of the energy storage unit;

[0054] Vsamp: Current sharing bus sampling signal;

[0055] Vref: Reference signal;

[0056] iL: Sampling signal of inductor current;

[0057] Iref: Current reference signal for the energy storage unit;

[0058] Duty: The duty cycle of the control signal;

[0059] Vth1: First voltage threshold;

[0060] Vth2: Second voltage threshold;

[0061] Vth3: Third voltage threshold;

[0062] Vth4: Fourth voltage threshold;

[0063] S10~S30: Steps;

[0064] S100~S500: Steps. Detailed Implementation

[0065] The technical content and detailed description of the present invention are explained below with reference to the accompanying drawings.

[0066] Please see Figure 1The diagram shown is a circuit block diagram of the power supply system of the power module combined with the energy storage module of the present invention. The power supply system includes at least one power supply unit (PSU) 10 and at least one energy storage module (CBU) 20. The power supply module 10 includes, for example but not limited to, a front-end power factor correction circuit (PFC) 11 and a rear-end DC / DC converter 12. The front-end power factor correction circuit (PFC) 11 receives AC power Vac and converts it to DC power, which is then converted to DC power by the rear-end DC / DC converter 12 before being output. The output side of the rear-end DC / DC converter 12 is connected to a load 50 (see [reference]). Figure 3 or Figure 4 ), and to supply power to load 50. In some embodiments, the subsequent DC / DC converter 12 may also be a unipolar AC / DC converter.

[0067] The energy storage module 20 mainly includes a bidirectional DC / DC converter 21 and an energy storage unit 22. There are many architectures for the bidirectional DC / DC converter 21; this invention uses a common bidirectional buck / boost converter as an example, but this is not intended to limit the invention. Similarly, the energy storage unit 22 can be implemented using energy storage elements with energy storage functions; this invention uses an energy storage capacitor C2 (see [reference]). Figure 2 The invention is illustrated using an example, but is not limited thereto. Furthermore, the energy storage capacitor C2 can be, for example, a supercapacitor.

[0068] Specifically, such as Figure 1 As shown, the output of each power module 10 is connected to the load 50, and each power module 10 converts its output current into a voltage signal and transmits it to the current sharing bus. The output of each energy storage module 20 is connected, and each energy storage module 20 includes a bidirectional DC / DC converter 21 and an energy storage unit 22. The first terminal of the bidirectional DC / DC converter 21 is connected to the energy storage unit 22, and the second terminal of the bidirectional DC / DC converter 21 is connected to the output of the power module 10. Each energy storage module 20 also includes a controller configured to execute the control method of the energy storage module 20. The voltage signal on the current sharing bus is the current sharing bus signal.

[0069] Specifically, when the load 50 is too heavy, without the energy storage module 20, the input current of the power module 10 would be too high. However, when the energy storage module 20 is connected, it is controlled to operate in discharge mode, releasing energy from the energy storage unit 22 to the load 50 via the bidirectional DC / DC converter 21, thus working together with the power module 10 to supply power to the load 50 and keeping the input current constant. Conversely, when the load 50 is too light, the energy storage module 20 is controlled to operate in charging mode, allowing excess input power to be fed into the energy storage unit 22 via the bidirectional DC / DC converter 21 to charge the energy storage unit 22, thereby keeping the input current of the power module 10 constant. Therefore, by providing or receiving current through the energy storage module 20, the output current of the power module 10 does not need to increase or decrease rapidly in a short period of time. This allows the power module 10 to maintain a constant input current and reduce its impact on the power grid.

[0070] Please see Figure 2 The diagram shown is a circuit diagram of the energy storage module of the present invention. As previously described, the bidirectional DC / DC converter 21 of the energy storage module 20 is illustrated using a bidirectional buck-boost converter as an example. Therefore, the bidirectional DC / DC converter 21 includes an inductor L1, a first switch S1, a second switch S2, and a capacitor C1. When the energy storage module 20 operates in discharge mode, the bidirectional DC / DC converter 21 operates in boost mode; when the energy storage module 20 operates in charging mode, the bidirectional DC / DC converter 21 operates in buck mode. Of course, in other embodiments, the opposite may also occur, depending on the configuration of the energy storage unit 22.

[0071] Please see Figure 3The diagram shows a schematic block diagram of the single power supply module and single energy storage module of the present invention. The power supply module 10-1 converts its output current into a voltage signal and connects it to the current sharing bus. This voltage signal on the current sharing bus is called the current sharing bus signal V_ishare. For example, according to the ORV3 (Open Rack Standard V3) specifications, when the power supply module 10-1 outputs 50% of its rated current, the current sharing bus signal V_ishare is 3.5 volts; when the power supply module 10-1 outputs 100% of its rated current, the current sharing bus signal V_ishare is 7 volts. The energy storage module 20-1 can obtain the corresponding load information simply by sampling the current sharing bus signal V_ishare on the current sharing bus. Typically, the current sharing bus signal V_ishare is a signal positively correlated with the output current of the power supply module 10-1, allowing the energy storage module 20-1 to estimate the load condition using the current sharing bus signal V_ishare provided by the power supply module 10-1. For example, a large value of the current sharing bus signal V_ishare indicates that the load 50 requires more power. Conversely, a small value indicates that the load 50 requires less power. A large rate of change in the value of the current sharing bus signal V_ishare indicates that the load 50 is rapidly increasing or decreasing. Therefore, by using the current sharing bus signal V_ishare, there is no need to add additional devices to sample the output current of the power module 10-1 to obtain load information. Furthermore, since the power module 10-1 is typically a pre-packaged unit without a pre-defined location for current sampling, the load information can be cleverly obtained by utilizing the existing information within the power module 10-1.

[0072] Please see Figure 4 As shown, it is a schematic block diagram of multiple power supply modules and multiple energy storage modules of the present invention. Compared to Figure 3 The single power supply module 10-1 and the single energy storage module 20-1 shown are shown. Figure 4This diagram illustrates the parallel operation of multiple (two) power modules 10-1 and 10-2, in conjunction with the coordinated operation of multiple (two) energy storage modules 20-1 and 20-2. In this parallel power module architecture, each power module 10-1 and 10-2 converts its output current into a corresponding voltage signal, and these multiple voltage signals are connected to a shared current-sharing bus. Generally, systems with multiple power modules in parallel require current sharing. Therefore, each power module 10-1 and 10-2 compares its output current with the current-sharing bus signal V_ishare on the shared bus and makes corresponding adjustments to achieve current sharing. For example, if the voltage signal corresponding to the output current of power module 10-1 is lower than the current-sharing bus signal V_ishare, it indicates that power module 10-1 is supplying less current. In this case, the control circuit will control power module 10-1 to output more power, i.e., increase its output current, and vice versa. Therefore, the output current of each power module 10-1 and 10-2 tends to be the same, achieving the purpose of load sharing. That is, the current sharing bus signal V_ishare can characterize the average load information of multiple power modules.

[0073] Furthermore, through the coordinated operation of the two energy storage modules 20-1 and 20-2 and the two power modules 10-1 and 10-2, when the load 50 is too heavy, the energy storage modules 20-1 and 20-2 can be controlled to operate in discharge mode, releasing energy to the load 50; or when the load 50 is too light, the energy storage modules 20-1 and 20-2 can be controlled to operate in charging mode, so that the excess input power charges the energy storage units 22 of the energy storage modules 20-1 and 20-2, thus keeping the input current of the power modules 10-1 and 10-2 constant. In addition, although the figure uses two power modules and two energy storage modules as an example, it should be understood that the number of power modules and energy storage modules is not a one-to-one correspondence; the number of parallel modules can be set according to the needs of the load 50. In other embodiments, multiple power modules are connected in parallel and placed in the same housing, and multiple energy storage modules are connected in parallel and placed in the same housing, both placed in power supply racks.

[0074] Please see Figure 7 As shown, it is a flowchart of the control method of the energy storage module of the present invention, in conjunction with... Figures 1-4 The control method proposed in this invention is used to control energy storage modules (such as...). Figure 1Taking the energy storage module 20 shown as an example (but not as a limitation of the present invention), the control is used to compensate for the input current fluctuations of the power module 10, that is, to ensure that the input current of the power module 10 remains constant regardless of whether the load 50 is too heavy or too light, or even when it increases or decreases rapidly. The control method of the energy storage module 20 includes the following steps: First, the power module 10 provides a current sharing bus signal V_ishare (step S10). Then, according to the current sharing bus signal V_ishare, the operating mode of the energy storage module 20 is controlled (step S20), and the energy storage module 20 is used to compensate for the input current fluctuations of the power module 10 (step S30). The operating mode mentioned in step S20 includes the energy storage module 20 operating in a pre-charging mode or in a backup power mode, which will be described in detail later.

[0075] Specifically, please see Figure 8 The diagram shows a flowchart of the detailed control method for the energy storage module of the present invention. First, after the energy storage module 20 is connected to the power module 10, the energy storage module 20 is controlled to enter a pre-charge mode (step S100), and then the energy storage unit 22 of the energy storage module 20 is pre-charged (step S200). Through the pre-charge operation, the voltage of the energy storage unit 22 can be charged to a preset value.

[0076] Then, it is determined whether the voltage of the energy storage unit 22 has been charged to a preset value (step S300). If the determination in step S300 is "no", then step S200 is executed to continuously precharge the energy storage unit 22.

[0077] It is worth mentioning that in the pre-charging operation of the energy storage unit 22 of the energy storage module 20 in this invention, it is desirable to achieve two objectives: first, to prevent the energy storage unit 22 from causing overload of the power module 10 during the pre-charging process; and second, to prevent the input current of the power module 10 from fluctuating during the pre-charging process. Therefore, this invention further proposes a solution.

[0078] Please see Figure 5The diagram shows a block diagram of the control loop of the energy storage unit of the present invention. The current sharing bus signal V_ishare is sampled to obtain the current sharing bus sampling signal Vsamp, and the operating mode of the energy storage module 20 is controlled based on the difference between the reference signal Vref and the current sharing bus sampling signal Vsamp. In the pre-charge mode, the reference signal Vref is set to k times the rated value of the current sharing bus signal V_ishare, where k is less than 1. The rated value of the current sharing bus signal V_ishare represents the output current when the power module 10 outputs its rated power. In the backup power mode, the reference signal Vref represents the average power of the power module 10, and the reference signal Vref is obtained by processing the current sharing bus signal V_ishare. It should be understood that there are many ways to obtain the reference signal Vref. For example, the reference signal Vref can be the average value of the current sharing bus sampling signal Vsamp over a period of time, or the reference signal Vref can be the value obtained by filtering the current sharing bus sampling signal Vsamp. The present invention does not limit this.

[0079] During pre-charging of the energy storage unit 22, the relationship between the reference signal Vref and the current sharing bus sampling signal Vsamp is continuously monitored. The current sharing bus signal V_ishare, which is inherent in the power module 10, is used as the feedback quantity characterizing the output current of the power module 10, eliminating the need for an additional power module 10 output current sampling circuit. Furthermore, to prevent overload of the power module 10, the reference signal Vref is set to k * V_ishare_full, where V_ishare_full is the value of the current sharing bus signal V_ishare converted from the output current of the power module 10 at full load power (rated power). Here, k is less than 1. The purpose is to prevent the power module 10 from pre-charging the energy storage unit 22 when it is close to full load in pre-charging mode, thus avoiding overload of the power module 10.

[0080] For ease of explanation, assume that when the power module 10 outputs its rated power, the current sharing bus signal V_ishare is 7 volts. In one case, the reference signal Vref is set to 6 volts, i.e., k = 85.71%. When the current sharing bus sampling signal Vsamp (e.g., 3 volts) is less than the reference signal Vref, the difference between the reference signal Vref and the current sharing bus sampling signal Vsamp produces a positive error. This error is calculated by, for example, but not limited to, a PI controller to generate a positive current reference signal Iref, i.e., the current reference signal of the energy storage unit 22. Further, the error generated by subtracting the current reference signal Iref from the sampling signal iL of the inductor current in the bidirectional DC / DC converter 21 is calculated by, for example, but not limited to, a PI controller, and finally generates a control signal Duty that controls the duty cycle of the switching transistors in the bidirectional DC / DC converter 21. In this case, the power module 10 can continuously pre-charge the energy storage unit 22.

[0081] Once the current sharing bus sampling signal Vsamp (e.g., 6.5 volts) is greater than the reference signal Vref (6 volts), the difference between the reference signal Vref and the current sharing bus sampling signal Vsamp produces a negative error. This error is calculated by the PI controller, gradually reducing the current reference signal Iref to zero, ultimately controlling the bidirectional DC / DC converter 21 to stop operating. In this case, the power module 10 interrupts the pre-charging of the energy storage unit 22.

[0082] In this example, during the pre-charging process of the power module 10 to the energy storage unit 22, it is necessary to ensure that the power module 10 does not exceed a certain set load. Therefore, as long as the power output of the power module 10 does not exceed 85.71% of the full load power, the power module 10 can continuously pre-charge the energy storage unit 22. Once the power output of the power module 10 exceeds 85.71% of the full load power, pre-charging of the energy storage unit 22 will cease. In some embodiments, k can be set by estimating the average load based on the load conditions.

[0083] As mentioned above, in pre-charging mode, in addition to avoiding overload of the power module 10, it is also necessary to prevent the instantaneous excessive current from the power module 10 charging the energy storage unit 22 during rapid pre-charging, which could cause a jump in the input current of the power module 10. Therefore, in pre-charging mode, it is necessary to control the current of the power module 10 charging the energy storage unit 22 to not exceed a predetermined current limit value. In one embodiment, the predetermined current limit value can be set to a fixed value, but is not a limitation thereof. In other embodiments, the predetermined current limit value can be set to a fixed first current limit value in the first pre-charging stage, and a value related to the power value of the power module 10 charging the energy storage unit 22 and / or the voltage Vc of the energy storage unit 22 in the second pre-charging stage.

[0084] Please see Figure 6 As shown, this is a waveform diagram of the energy storage unit of the present invention undergoing pre-charging. Figure 6 As shown, the horizontal axis represents the voltage Vc of the energy storage unit 22, and the vertical axis represents the output power of the power module 10. To prevent the energy storage unit 22 from being pre-charged with a large current (high power) at the beginning, which would affect its lifespan, and to prevent the input current of the power module 10 from jumping during the pre-charging process, a small current is usually used at the beginning of the pre-charging (when the voltage Vc of the energy storage unit 22 is low), for example, a small constant current (relatively low power).

[0085] Therefore, as Figure 6 As shown, when the voltage Vc of the energy storage unit 22 is less than the first voltage threshold Vth1, the energy storage module 20 is controlled to enter the first pre-charging stage, and during the first pre-charging stage, the current supplied by the power module 10 to the energy storage unit 22 is controlled not to exceed the first current limit value. That is, the maximum value of the current reference signal Iref of the energy storage unit 22 is limited, i.e., Iref_limit = I1.

[0086] Then, when the voltage Vc of the energy storage unit 22 reaches the first voltage threshold Vth1, the energy storage module 20 is controlled to enter the second pre-charging stage. During the second pre-charging stage, the current supplied by the power module 10 to the energy storage unit 22 is controlled not to exceed the ratio of the first power threshold to the voltage of the energy storage unit 22, i.e., power-limited charging is entered, limiting the maximum value of the current reference signal Iref of the energy storage unit 22, i.e., Iref_limit = Plimit / Vc. Specifically, when entering the second pre-charging stage, the first power threshold is controlled to gradually increase the power value supplied by the power module 10 to the energy storage unit 22 from the end of the first pre-charging stage to the maximum power limit. At this time, the voltage Vc of the energy storage unit 22 is charged to the second voltage threshold Vth2, and thereafter the charging power value remains unchanged at this maximum power limit.

[0087] When the power value of the power module 10 charging the energy storage unit 22 reaches the maximum power limit, the power module 10 charges the energy storage unit 22 at the maximum power limit until the voltage of the energy storage unit 22 reaches the third voltage threshold Vth3. Then, the first power threshold is controlled to gradually decrease from the maximum power limit until the voltage Vc of the energy storage unit 22 reaches the preset value (e.g., the fourth voltage threshold Vth4), thereby gradually exiting the pre-charging mode.

[0088] Incidentally, in Figure 6 During the pre-charging process, even in the high-power pre-charging stage of the second pre-charging phase, it is still subject to... Figure 5 The control loop mechanism is limited to ensure that the power module 10 is not overloaded.

[0089] Please see again Figure 8 When the voltage Vc of the energy storage unit 22 is charged to a preset value, the energy storage module 20 is controlled to enter the backup power mode (step S400), and the pre-charging mode ends. In the backup power mode, the energy storage unit 22 is controlled to charge or discharge to the power module 10 according to the current sharing bus signal V_ishare (step S500). That is, after the pre-charging mode ends, the energy storage module 20 enters the backup power mode, thereby receiving the current sharing bus signal V_ishare provided by the power module 10, and controlling the energy storage unit 22 to be charged or the energy storage unit 22 to discharge to the power module 10 according to the current sharing bus signal V_ishare. Specifically, in the backup power mode, when the current sharing bus sampling signal Vsamp is greater than the reference signal Vref, the energy storage unit 22 is controlled to operate in the discharge mode so that the energy storage unit 22 releases energy to the load 50. Conversely, when the current sharing bus sampling signal Vsamp is less than the reference signal Vref, the energy storage unit 22 is controlled to operate in the charging mode so that the power module 10 stores energy in the energy storage unit 22.

[0090] In summary, the present invention has the following features and advantages:

[0091] 1. By providing or receiving current through the energy storage module 20, the output current of the power module 10 does not need to increase or decrease rapidly in a short period of time. In this way, the power module 10 does not need to rapidly increase or decrease the current it draws from its input power source, thus keeping the input current constant and reducing the impact on the power grid.

[0092] 2. To prevent the energy storage unit 22 from causing overload of the power module 10 during the pre-charging process.

[0093] 3. To prevent the input current of the power module 10 from jumping during the pre-charging process of the energy storage unit 22.

[0094] 4. During the pre-charging process, maintain the normal service life of the energy storage unit 22.

[0095] The above description is merely a detailed explanation and accompanying drawings of preferred embodiments of the present invention, and the features of the present invention are not limited thereto, nor are they intended to limit the present invention. The entire scope of the present invention should be determined by the following claims. All embodiments that conform to the concept of the claims of the present invention and similar variations thereof should be included in the scope of the present invention. Any variations or modifications that can be easily conceived by those skilled in the art within the field of the present invention can be covered by the following claims of the present invention.

Claims

1. A control method for an energy storage module, wherein the energy storage module includes a bidirectional DC / DC converter and an energy storage unit, wherein a first terminal of the bidirectional DC / DC converter is connected to the energy storage unit, characterized in that, The control method includes: controlling the operating mode of the energy storage module according to a current sharing bus signal provided by a power module connected to the second terminal of the bidirectional DC / DC converter, wherein the energy storage module is used to compensate for the input current fluctuation of the power module.

2. The control method according to claim 1, characterized in that, Also includes: After the energy storage module is connected to the power module, the energy storage module is controlled to enter a pre-charging mode to pre-charge the energy storage unit. When the voltage of the energy storage unit is charged to a preset value, the energy storage module is controlled to enter a backup power mode. In the backup power mode, the energy storage unit is controlled to charge or discharge to the power module according to the current sharing bus signal.

3. The control method according to claim 1, characterized in that, Also includes: The current sharing bus signal is sampled to obtain a current sharing bus sampling signal, and the operating mode of the energy storage module is controlled according to the difference between a reference signal and the current sharing bus sampling signal.

4. The control method according to claim 3, characterized in that, Also includes: The difference between the reference signal and the current sharing bus sampling signal generates a current reference signal corresponding to the bidirectional DC / DC converter, and the operating mode of the energy storage module is controlled based on the current reference signal and the inductor current of the bidirectional DC / DC converter.

5. The control method according to claim 3, characterized in that, Also includes: In a pre-charge mode, the reference signal is set to k times the rated value of the current sharing bus signal, where k is less than 1, and the rated value of the current sharing bus signal characterizes the output current when the power module outputs rated power.

6. The control method according to claim 3, characterized in that, Also includes: In a standby power mode, the reference signal characterizes the average power of the power module.

7. The control method according to claim 5, characterized in that, Also includes: In the pre-charge mode, the current supplied by the power module to the energy storage unit is controlled to not exceed a predetermined current limit value.

8. The control method according to claim 7, characterized in that, The predetermined flow limit value is a fixed value.

9. The control method according to claim 7, characterized in that, The predetermined current limiting value is a fixed first current limiting value in the first pre-charging phase and a value related to the power value of the power module charging the energy storage unit and / or the voltage of the energy storage unit in the second pre-charging phase.

10. The control method according to claim 9, characterized in that, Also includes: When the voltage of the energy storage unit is less than a first voltage threshold, the energy storage module is controlled to enter the first pre-charging stage, and during the first pre-charging stage, the current supplied by the power module to the energy storage unit is controlled not to exceed the first current limit value.

11. The control method according to claim 9, characterized in that, Also includes: When the voltage of the energy storage unit reaches the first voltage threshold, the energy storage module is controlled to enter the second pre-charging stage, and during the second pre-charging stage, the current of the power module charging the energy storage unit is controlled not to exceed the ratio of a first power threshold to the voltage of the energy storage unit.

12. The control method according to claim 11, characterized in that, During the second pre-charging phase, the first power threshold is controlled to gradually increase from the power value of the power module charging the energy storage unit at the end of the first pre-charging phase to the maximum power limit.

13. The control method according to claim 12, characterized in that, When the power value of the power module charging the energy storage unit reaches the maximum power limit, the energy storage unit is charged at the maximum power limit until the voltage of the energy storage unit reaches a third voltage threshold. Then, the first power threshold is controlled to gradually decrease from the maximum power limit until the voltage of the energy storage unit reaches a preset value, thereby gradually exiting the pre-charging mode.

14. The control method according to claim 3, characterized in that, Also includes: In a standby power mode, when the current sharing bus sampling signal is greater than the reference signal, the energy storage unit is controlled to operate in a discharge mode so that the energy storage unit releases energy to the load; when the current sharing bus sampling signal is less than the reference signal, the energy storage unit is controlled to operate in a charging mode so that the power module stores energy in the energy storage unit.

15. An energy storage module, characterized in that, include: A bidirectional DC / DC converter and an energy storage unit are provided, wherein a first terminal of the bidirectional DC / DC converter is connected to the energy storage unit, and a second terminal of the bidirectional DC / DC converter is connected to the output terminal of a power module; each energy storage module further includes a controller configured to employ the control method according to any one of claims 1-14.

16. A power supply system, characterized in that, include: At least one power module, the output of each power module is connected to a load, wherein each power module converts its own output current into a voltage signal and transmits it to a current sharing bus; At least one energy storage module, wherein the output terminals of each energy storage module are connected, and each energy storage module includes a bidirectional DC / DC converter and an energy storage unit, wherein a first terminal of the bidirectional DC / DC converter is connected to the energy storage unit, and a second terminal of the bidirectional DC / DC converter is connected to the output terminal of the power module; each energy storage module further includes a controller configured to employ the control method of any one of claims 1-14, wherein the voltage signal on the current sharing bus is the current sharing bus signal.

17. The power supply system according to claim 16, characterized in that, The at least one power module is housed in the same housing.

18. The power supply system according to claim 16, characterized in that, The at least one energy storage module is housed in the same casing.

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