Power distribution system based on bus voltage regulation and method thereof, storage medium

Abstract

This application relates to the field of microgrid technology, disclosing a power distribution system and method based on bus voltage regulation, as well as a storage medium. The system includes a DC power supply module and an AC power supply module, which are connected to a load via the same bus. The DC power supply module includes a first power adjustment unit, which adjusts the voltage output from the DC power supply module to the bus based on the actual output power and a preset maximum output power. The AC power supply module includes a second power adjustment unit, which adjusts the voltage output from the AC power supply module to the bus to its rated voltage after detecting that the bus voltage has been adjusted, thereby achieving power distribution between the DC and AC power supply modules. In this way, the entire system eliminates the need for communication control between a central controller and a local controller, reducing the system's dynamic response time and improving its responsiveness.

Description

Technical Field

[0001] This application relates to the field of microgrid technology, and in particular to a power distribution system and method based on bus voltage regulation, and a storage medium thereof. Background Technology

[0002] Against the backdrop of the global energy transition, new energy sources such as wind and solar power are developing rapidly. However, the large-scale grid connection of distributed power sources has impacted traditional power grids, highlighting their high operating costs and weak regulation capabilities. In contrast, distributed power supply has significant advantages such as high energy utilization, low environmental pollution, and strong power supply flexibility, making it an effective way to solve energy crises and environmental problems. Independent DC microgrids can effectively integrate distributed power sources and fully leverage their advantages.

[0003] In related technologies, microgrids typically employ centralized and distributed control. Centralized control involves the microgrid's central controller collecting real-time data from each distributed power supply unit via a communication network, calculating the control variables for each controlled unit, and sending this data back to the local controller to achieve global power allocation. Distributed control utilizes the local controller to exchange operational information between adjacent distributed power supply units via point-to-point bidirectional links, ultimately achieving global power allocation. Because these technologies still require communication control from either the central or local controller to achieve power allocation, the system's responsiveness is poor. Summary of the Invention

[0004] The purpose of this application is to provide a power distribution system and method based on bus voltage regulation, as well as a storage medium, which improves the responsiveness of the system.

[0005] To address the aforementioned technical problems, embodiments of this application provide a power distribution system based on bus voltage regulation, including a DC power supply module and an AC power supply module, which are connected to a load via the same bus. The DC power supply module includes a first power adjustment unit, which adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and a preset maximum output power. The AC power supply module includes a second power adjustment unit, which adjusts the voltage output from the AC power supply module to the bus to a rated voltage after detecting that the bus voltage has been adjusted, thereby achieving power distribution between the DC power supply module and the AC power supply module.

[0006] Embodiments of this application also provide a power distribution method based on bus voltage regulation. This method is applied to a power distribution system based on bus voltage regulation. The system includes a DC power supply module and an AC power supply module, which are connected to a load via the same bus. A first power adjustment unit in the DC power supply module adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and a preset maximum output power. After detecting that the bus voltage has been adjusted, a second power adjustment unit in the AC power supply module adjusts the voltage output from the AC power supply module to the bus to the rated voltage, thereby achieving power distribution between the DC power supply module and the AC power supply module.

[0007] Embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements any of the above-described power distribution methods based on bus voltage regulation.

[0008] In this embodiment, the first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on the comparison between the actual output power and the maximum output power of the DC power supply module. This allows the second power adjustment unit to automatically adjust the voltage output from the AC power supply module to the bus to the rated voltage after detecting that the bus voltage has been adjusted. This enables the redistribution of power in the system. The entire system does not require communication between the central controller and the local controller, reducing the dynamic response time of the system and thus improving its responsiveness. Attached Figure Description

[0009] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0010] Figure 1 This is a schematic diagram of a power distribution system based on bus voltage regulation according to an embodiment of this application;

[0011] Figure 2 This is a schematic diagram of a power distribution system based on bus voltage regulation according to another embodiment of this application;

[0012] Figure 3 This is a schematic flowchart of a power distribution method based on bus voltage regulation according to an embodiment of this application;

[0013] Figure 4 This is a schematic diagram of a discharge control strategy for a bidirectional energy converter according to an embodiment of this application;

[0014] Figure 5 This is a schematic diagram of a charging control strategy for a bidirectional energy converter according to an embodiment of this application;

[0015] Figure 6 This is a schematic diagram of the constant voltage control strategy of a constant voltage rectifier according to an embodiment of this application. Detailed Implementation

[0016] DC microgrid control strategies are mainly classified into three categories: centralized, decentralized, and distributed. The advantage of centralized control is that all relevant data is stored in the central controller, allowing for centralized processing of global data and providing a good foundation for advanced control functions. However, when the central controller fails, the transmission of control commands throughout the system will be interrupted, making it impossible to achieve the control objectives. In decentralized control, each power supply unit of the microgrid is controlled by its own local controller. Each power supply unit controls itself independently based on local measurement information (such as voltage and frequency), only receiving local information such as frequency and voltage. There is no digital communication link; power line carrier is used as the only physical communication medium for communication between power supply units. While this architecture avoids the risk of communication failure, the lack of global information interaction makes the system prone to unstable or undesirable operating states (such as voltage exceeding limits and uneven power distribution), and it is rarely used alone in practical engineering. In distributed control, the local controllers of each power supply unit use limited-range bidirectional communication (usually only exchanging data with adjacent nodes) to collaboratively avoid the problems of unachievable control objectives and lack of information interaction when the sole central controller fails.

[0017] When using centralized or distributed control to distribute power among the various power supply units in a DC microgrid, the central controller or local controller is still required for communication control. This results in communication delays, leading to a longer dynamic response time and poor system responsiveness.

[0018] Based on this, this application provides a power distribution system and method based on bus voltage regulation, as well as a storage medium. The first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on the comparison between the actual output power and the maximum output power of the DC power supply module. After detecting that the bus voltage has been adjusted, the second power adjustment unit automatically adjusts the voltage output from the AC power supply module to the bus to the rated voltage. This allows for the redistribution of power in the system. The entire system does not require communication between the central controller and the local controller, reducing the dynamic response time of the system and thus improving its responsiveness.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0020] Figure 1 This is a schematic diagram of a power distribution system based on bus voltage regulation according to an embodiment of this application.

[0021] like Figure 1 As shown, the power distribution system 10 based on bus voltage regulation includes a DC power supply module 101 and an AC power supply module 102, which are connected to the load 103 via the same bus.

[0022] The DC power supply module 101 includes a first power adjustment unit 1011, which is used to adjust the voltage output from the DC power supply module 101 to the bus according to the actual output power of the DC power supply module 101 and the preset maximum output power. The AC power supply module 102 includes a second power adjustment unit 1021, which is used to adjust the voltage output from the AC power supply module 102 to the bus to the rated voltage after detecting that the voltage of the bus has been adjusted, so as to realize the output power distribution between the DC power supply module 101 and the AC power supply module 102.

[0023] It is understood that the power distribution system 10 based on bus voltage regulation can be applied in off-grid communication base stations. During most operating hours, when the base station load is low at night or during daytime with sufficient sunlight, the DC power supply module 101 can independently support the load consumption, while the AC power supply module 102 is in standby or off state. The system operates quietly, efficiently, and at a low cost. Therefore, the power distribution system 10 based on bus voltage regulation mainly relies on the DC power supply module 101 for operation. When the power distribution system 10 based on bus voltage regulation detects that the energy stored in the DC power supply module 101 is insufficient or that the load demand suddenly surges, the AC power supply module 102 will intervene and become the main power source to help alleviate the power supply pressure on the DC power supply module 101.

[0024] like Figure 1As shown, DC power supply module 101 and AC power supply module 102 are connected to load 103 via the same bus. DC power supply module 101 provides DC power to load 103, and AC power supply module 102 provides AC power to load 103. The DC power supply module 101 primarily provides power to load 103. When the power provided by DC power supply module 101 is insufficient to support the consumption of load 103, AC power supply module 102 provides auxiliary power to load 103 to maintain its operation. AC power supply module 102 is also used to provide power to DC power supply module 101 when its stored energy is insufficient.

[0025] A busbar typically refers to a common connection point in a power transmission and distribution system. A busbar is a node in a power system where generators, batteries, and loads can all be connected. The actual output power of the DC power supply module 101 is calculated by sampling the voltage and current of the DC power supply module 101.

[0026] The maximum output power of the DC power supply module 101 is limited by its own voltage. When the voltage of the DC power supply module 101 is lower than the voltage threshold, the DC power supply module 101 switches from the discharge mode to the charging mode to prevent over-discharge. The maximum output power is shown in formula (1).

[0027] Formula (1)

[0028] in, The voltage of the DC power supply module 101 is sampled in real time. The rated full-charge voltage of the DC power supply module 101, The low voltage threshold of the DC power supply module 101 This is the maximum output power of the DC power supply module 101. The first power adjustment unit 1011 automatically adjusts the maximum output power according to the voltage of the DC power supply module 101. The lower the voltage, the lower the maximum output power.

[0029] Specifically, the first power adjustment unit 1011 of the DC power supply module 101 continuously monitors the actual output power consumption of the DC power supply module 101 and compares the actual output power with the maximum output power of the DC power supply module 101. Based on the comparison result, the voltage output to the bus is adjusted. When the actual output power is greater than the maximum output power, it indicates that the DC power supply module 101 has entered an overload state. If the DC power supply module 101 continues to supply power mainly to the load 103, it will damage the DC power supply module 101. The AC power supply module 102 is usually a generator or a high-capacity power device that can provide a stable and high-power DC output. Therefore, it is necessary to redistribute the power between the DC power supply module 101 and the AC power supply module 102, allowing the AC power supply module 102 to bear part of the output power, thereby protecting the DC power supply module 101 in a timely manner.

[0030] Similarly, when the actual output power is less than the maximum output power, it means that the output power provided by the DC power supply module 101 can meet the consumption of the load 103. The DC power supply module 101 is usually a local distributed power device such as a battery or photovoltaic. This power device usually stores energy in advance, and prioritizing the use of the stored energy can make effective use of it. Therefore, it is necessary to redistribute the power between the DC power supply module 101 and the AC power supply module 102 so that the DC power supply module 101 can bear most of the output power to meet the power consumption of the load 103.

[0031] Furthermore, in some embodiments, the first power adjustment unit 1011 is specifically used to: compare the actual output power of the DC power supply module 101 with the maximum output power, and when the actual output power is greater than the maximum output power, the first power adjustment unit 1011 reduces the voltage output by the DC power supply module 101 to the bus.

[0032] Continue to refer to Figure 1 The AC power supply module 102 starts first. Its internal second power adjustment unit 1021 adjusts the voltage output from the AC power supply module 102 to the bus, ensuring the output voltage is the rated voltage. At this time, the load 103 has not yet consumed energy, so no current flows in the AC power supply module 102. When the DC power supply module 101 is in discharge mode, it monitors the initial voltage of its bus before operation. Ideally, the initial voltage of the bus should be equal to the rated voltage output by the second power adjustment unit 1021. However, due to system losses or external influences, the initial voltage of the bus may be slightly lower than the rated voltage.

[0033] Next, the first power adjustment unit 1011 continuously monitors the actual output power of the DC power supply module 101 and compares the actual output power with the maximum output power of the DC power supply module 101. When the actual output power is greater than the maximum output power, it indicates that the DC power supply module 101 has entered an overload state. Therefore, it is necessary to redistribute the power between the DC power supply module 101 and the AC power supply module 102. At this time, the first power adjustment unit 1011 will reduce the voltage output from the DC power supply module 101 to the bus, so that the voltage at its output terminal is lower than the initial voltage of the bus, and the output power of the DC power supply module 101 is maintained at the maximum output power, thereby protecting the DC power supply module 101 in a timely manner while meeting the consumption of the load 103.

[0034] Next, the second power adjustment unit 1021 of the AC power supply module 102 detects that the DC power supply module 101 has reduced the bus voltage, and determines that the bus voltage is lower than the rated voltage of the AC power supply module 102 itself. The second power adjustment unit 1021 will readjust the voltage output to the bus to pull the bus voltage back to the rated voltage. At this time, since the load 103 continues to consume energy, the output current on the AC power supply module 102 side gradually increases, which causes the AC power supply module 102 to adjust the voltage at its output terminal to the rated voltage, and the output power at its output terminal is also increased compared with the output power at startup, thereby automatically compensating for the power consumption of the load 103.

[0035] In this way, the output voltage of the DC power supply module to the bus is adjusted by the first power adjustment unit, the output power of the microgrid is dynamically distributed, and the adjusted voltage is adjusted to the rated voltage by the second power adjustment unit, automatically compensating the output power, thereby eliminating the need for communication control by the central controller or local controller and improving the responsiveness of the system.

[0036] Furthermore, in some embodiments, the first power adjustment unit 1011 is specifically used to: increase the voltage output to the bus by the DC power supply module 101 when the actual output power is less than the maximum output power.

[0037] In other words, when the actual output power is less than the maximum output power of the DC power supply module 101, it means that the output power provided by the DC power supply module 101 can meet the consumption of the load 103. At this time, the first power adjustment unit 1011 will increase the voltage output from the DC power supply module 101 to the bus, so that the voltage at the output end is higher than the initial voltage of the bus. Then, the second power adjustment unit 1021 of the AC power supply module 102 will detect that the DC power supply module 101 has raised the voltage and determine that the bus voltage is higher than the rated voltage of the AC power supply module 102 itself. The second power adjustment unit 1021 will readjust the voltage output to the bus and pull the bus voltage back to the rated voltage, thereby reducing the output power of the AC power supply module 102 so that the DC power supply module 101 can meet the consumption of the load 103 and realize the redistribution of output power in the microgrid.

[0038] According to the power distribution system based on bus voltage regulation of this application, the first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on the comparison between the actual output power and the maximum output power of the DC power supply module. This allows the second power adjustment unit to automatically adjust the voltage output from the AC power supply module to the bus to the rated voltage after detecting that the bus voltage has been adjusted. This enables the redistribution of power in the system. The entire system does not require communication between the central controller and the local controller, reducing the dynamic response time of the system and thus improving the responsiveness of the system.

[0039] Figure 2 This is a schematic diagram of a power distribution system based on bus voltage regulation according to another embodiment of this application. Figure 2 As shown, in some embodiments, the DC power supply module 101 includes a DC power supply unit 1012 and a bidirectional energy converter 1013. The bidirectional energy converter 1013 is equipped with a first power adjustment unit 1011. The DC power supply unit 1012 is connected to the input side of the bidirectional energy converter 1013, and the output side of the bidirectional energy converter 1013 is connected to the load 103 via a bus. The AC power supply module 102 includes an AC power supply unit 1022 and a constant voltage rectifier 1023. The constant voltage rectifier 1023 is equipped with a second power adjustment unit 1021. The AC power supply unit 1022 is connected to the input side of the constant voltage rectifier 1023, and the output side of the constant voltage rectifier 1023 is connected to the load 103 via a bus.

[0040] Specifically, the bidirectional energy converter 1013 can be a bidirectional DC / DC driver (DC-DC driver). This bidirectional DC / DC driver is typically used in microgrids to coordinate energy distribution. It consists of power switching devices, inductors, capacitors, and other components. Based on pulse-width modulation (PWM) technology, it controls the magnitude and direction of the output voltage by adjusting the duty cycle of the power switching devices, thereby realizing bidirectional conversion and energy transfer between DC voltages (such as battery charging and discharging). The bidirectional energy converter 1013 can be in discharge mode or charging mode.

[0041] The constant voltage rectifier 1023 can be a constant voltage AC / DC driver (Alternating Current / Direct Current AC / DC driver) that can convert AC power into stable DC power to provide a precise and controllable DC power supply to the load 103. The constant voltage rectifier 1023 typically uses PWM technology to dynamically adjust the voltage by adjusting the duty cycle. The constant voltage rectifier 1023 can be in discharge mode.

[0042] The DC power supply unit 1012 can be a power device such as a battery or photovoltaic system. This DC power supply unit 1012 is connected to the bidirectional energy converter 1013 to provide power to the load 103. The AC power supply unit 1022 can be a power supply device that can provide AC power, such as a permanent magnet generator, synchronous generator, or asynchronous generator. This AC power supply unit 1022 is connected to the constant voltage rectifier 1023 to provide power to the load 103.

[0043] Continue to refer to Figure 2 The bidirectional energy converter 1013 and the constant voltage rectifier 1023 are connected to the same bus and together to the load 103. The constant voltage rectifier 1023 starts first, adjusting the voltage output to the bus to the rated voltage. At this time, the load 103 has not yet consumed energy, so there is no current flowing on the constant voltage rectifier 1023 side. When the bidirectional energy converter 1013 is in discharge mode, it monitors the initial voltage of its bus before operation.

[0044] When the bidirectional energy converter 1013 is in discharge mode, if it detects that the actual output power of the DC power supply unit 1012 is greater than the maximum output power, the bidirectional energy converter 1013 will reduce the voltage output from the DC power supply unit 1012 to the bus, so that the voltage at its output terminal is lower than the initial voltage of the bus, and the output power of the DC power supply unit 1012 is maintained at the maximum output power. In addition, when the constant voltage rectifier 1023 determines that the adjusted voltage is lower than the rated voltage of the AC power supply module 102 itself, it will readjust the adjusted voltage (i.e., increase the adjusted voltage) to the rated voltage. At this time, since the load 103 continues to consume energy, the output current on the AC power supply unit 1022 side gradually increases, which causes the AC power supply unit 1022 to adjust the voltage at its output terminal to the rated voltage, and the output power at its output terminal is also increased relative to the output power at startup, thereby automatically compensating for the consumption of the load 103.

[0045] Similarly, when the actual output power of the DC power supply unit 1012 is less than the maximum output power, the bidirectional energy converter 1013 will increase the voltage output from the DC power supply unit 1012 to the bus, so that the voltage at its output terminal is higher than the initial voltage of the bus. When the constant voltage rectifier 1023 determines that the adjusted voltage is higher than the rated voltage of the AC power supply module 102 itself, it will readjust the adjusted voltage (i.e. reduce the adjusted voltage) to the rated voltage, thereby reducing the output power of the AC power supply unit 1022 so that the bidirectional DC power supply unit 1012 can meet the consumption of the load 103.

[0046] In this way, the voltage of the bus is adjusted by a bidirectional energy converter, the output power distribution in the microgrid is dynamically adjusted, and the adjusted voltage is adjusted to the rated voltage by a constant voltage rectifier, automatically compensating for the output power, thus eliminating the need for communication control by a central controller or local controller and improving the responsiveness of the system.

[0047] Continue to refer to Figure 2 In some embodiments, the power distribution system 10 based on bus voltage regulation further includes a frequency converter 104, which is used to convert the DC power provided by the AC power supply module 102 and the DC power supply module 101 into AC power and supply the AC power to the load 103. The frequency converter 104 is a power electronic device, mainly used to convert DC power into AC power with adjustable frequency and voltage, and is typically used in scenarios involving grid connection of new energy sources.

[0048] Figure 3 This is a schematic flowchart illustrating a power distribution method based on bus voltage regulation according to an embodiment of this application. The method is applied to the power distribution system based on bus voltage regulation in the above embodiment. The system includes a DC power supply module and an AC power supply module 102, which are connected to the load via the same bus.

[0049] like Figure 3 As shown, the method includes:

[0050] S31: The first power adjustment unit in the DC power supply module adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and the preset maximum output power;

[0051] S32: After detecting that the bus voltage has been adjusted, the second power adjustment unit in the AC power supply module adjusts the voltage output from the AC power supply module to the bus to the rated voltage, so as to realize the output power distribution between the DC power supply module and the AC power supply module.

[0052] Specifically, the descriptions of the DC power supply module, AC power supply module, and load can be found in the above embodiments and will not be repeated here. Since the DC power supply module and AC power supply module are connected to the load through the same bus, the AC power supply module starts first. Its internal second power adjustment unit adjusts the voltage output from the AC power supply module to the bus so that the voltage output at its output terminal is the rated voltage. At this time, the load has not yet consumed energy.

[0053] When the DC power supply module is in discharge mode, the first power adjustment unit continuously monitors the actual output power of the DC power supply module and compares it with the maximum output power of the DC power supply module. When the actual output power is greater than the maximum output power, it indicates that the DC power supply module has entered an overload state. If the DC power supply module continues to supply power to the load, it will damage the DC power supply module. Therefore, it is necessary to redistribute the power between the DC power supply module and the AC power supply module. At this time, the first power adjustment unit will reduce the voltage output from the DC power supply module to the bus, and the output power of the DC power supply module will be maintained at the maximum output power, thereby protecting the DC power supply module in a timely manner.

[0054] Next, the second power adjustment unit of the AC power supply module detects that the DC power supply module has reduced the voltage and determines that the adjusted voltage is lower than the rated voltage of the AC power supply module itself. The second power adjustment unit then readjusts (i.e., increases) the adjusted voltage to the rated voltage. At this time, due to the continuous energy consumption of the load, the output current on the AC power supply module side gradually increases. Consequently, after the AC power supply module adjusts its output voltage to the rated voltage, its output power is also increased compared to the output power at startup, thus automatically compensating for the power consumption of the load. When the actual output power is less than the maximum output power, the corresponding power allocation strategy is described in the above embodiment and will not be repeated here.

[0055] According to the power distribution method based on bus voltage regulation of this application, the first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on the comparison between the actual output power and the maximum output power of the DC power supply module. This allows the second power adjustment unit to automatically adjust the voltage output from the AC power supply module to the bus to the rated voltage after detecting that the bus voltage has been adjusted. This enables the redistribution of power in the system. The entire system does not require communication between the central controller and the local controller, reducing the dynamic response time of the system and thus improving the responsiveness of the system.

[0056] In some embodiments, before the first power adjustment unit of the DC power supply module adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and the preset maximum output power, the power distribution method based on bus voltage regulation further includes: the bidirectional energy converter in the DC power supply module sampling the voltage of the DC power supply module; when the voltage is greater than the voltage threshold of the DC power supply module, the bidirectional energy converter enters a discharge mode to supply power to the load through the DC power supply module; when the voltage is less than the voltage threshold of the DC power supply module, the bidirectional energy converter enters a charging mode to charge the DC power supply module through the AC power supply module until the voltage is greater than the voltage threshold.

[0057] Specifically, the voltage threshold of the DC power supply module, as shown in formula (1), is (This refers to the low voltage threshold of the DC power supply module). The electrical energy stored in the DC power supply module is limited. To prevent over-discharge, a low voltage threshold is set. The bidirectional energy converter within the DC power supply module samples the module's voltage in real time. When the sampled voltage exceeds the voltage threshold, it enters discharge mode, supplying DC power to the load. When the voltage of the DC power supply module falls below the low voltage threshold... In order to protect the DC power supply module, the bidirectional energy converter enters charging mode at this time. It outputs AC power from the AC power supply module, and then its internal constant voltage rectifier converts the AC power into DC power, which is then transmitted to the bidirectional energy converter through the bus. The bidirectional energy converter then provides the DC power to the DC power supply module to charge it until the voltage of the DC power supply module is greater than the low voltage threshold. Then the charging operation to the DC power supply module will stop.

[0058] In this way, by monitoring the voltage of the DC power supply module through a bidirectional energy converter, the direction of energy transmission can be dynamically controlled under different voltage conditions, thereby switching between the discharge and charging states of the DC power supply module and preventing over-discharge of the DC power supply module.

[0059] In some embodiments, adjusting the voltage output from the DC power supply module to the bus includes: performing proportional-integral processing on the difference between the actual output power and the maximum output power to obtain a power output signal; performing proportional-integral processing on the power output signal and the difference between the current voltage and the target voltage to obtain a discharge current; performing proportional-integral processing on the difference between the discharge current and the current current of the DC power supply module to obtain a discharge voltage; and calculating the discharge duty cycle based on the discharge voltage and the current voltage, so that the first power adjustment unit adjusts the voltage output from the DC power supply module to the bus according to the discharge duty cycle.

[0060] Among them, the proportional-integral (PI) control works by making the output signal u(t) proportional to the current error signal e(t), enabling rapid response to voltage deviations. The integral-integral (I) control works by making the output signal u(t) proportional to the integral (cumulative sum) of the error signal e(t) over time, accumulating and eliminating historical errors to ensure long-term accuracy. The target voltage is a pre-set target voltage to be achieved during the discharge process.

[0061] For example, Figure 4 This is a schematic diagram of a discharge control strategy for a bidirectional energy converter according to an embodiment of this application. Figure 4 As shown, the second power adjustment unit in the bidirectional energy converter adjusts the voltage output to the bus while the bidirectional energy converter is in discharge mode, thereby adjusting the maximum output power of the DC power supply module. and the actual output power of the DC power supply module (The actual output power is calculated after sampling the voltage and current of the DC power supply module.) The difference is then processed to obtain the power deviation. The signal is then input to a power PI controller for PI processing to obtain the power output signal. Next, the target voltage of the bus where the bidirectional energy converter is located will be... and the current voltage sampled Perform differential processing to obtain the voltage deviation. The difference obtained is then compared with the power output signal. The input voltage is processed by a PI controller to obtain the discharge current. .

[0062] Finally, the discharge current and the current sampled by the bidirectional energy converter are used. Perform differential processing to obtain the current deviation. The current PI controller processes the output voltage to obtain the discharge voltage. Based on the discharge voltage and the current voltage, the discharge duty cycle is calculated. This allows the first power adjustment unit to adjust the voltage output from the DC power supply module to the bus according to the discharge duty cycle. At this point, the voltage at the output of the bidirectional energy converter is greater than the voltage at the input (determined by the DC power supply module), thus achieving dynamic adjustment of the voltage output to the bus. The power PI controller, voltage PI controller, and current PI controller are virtual control algorithms implemented through software design or digital logic, and their functions depend on physical hardware (such as the bidirectional energy converter).

[0063] It is understandable that traditional droop control is the core strategy for achieving non-communication power distribution in parallel operation of multiple generating units in a power system. Its design philosophy assumes that the line impedance from each distributed unit to the bus is the same, and by pre-setting a droop coefficient (virtual resistance), it achieves an ideal power distribution that is inversely proportional to the droop coefficient (the principle upon which traditional droop control is based). However, in the actual application scenarios of microgrids, the length of each line and the parameters such as the conductor are different, which makes the line impedance from each distributed power supply unit to the bus different. As a result, the power distribution is affected by the impedance and is not determined solely by the droop coefficient, thus leading to uneven power distribution and a large power distribution error.

[0064] To address the issue of large power distribution errors, this embodiment designs a power loop formed by the actual output power and the maximum output power, and performs integration processing on it to reduce the output power deviation of the bidirectional energy converter, thereby achieving more precise control over the output power.

[0065] In this way, the voltage output to the bus is adaptively adjusted through the voltage loop and current loop, and the output power is adaptively adjusted through the power loop, thereby realizing the redistribution of the system's power.

[0066] In some embodiments, charging a DC power supply module via an AC power supply module until the voltage exceeds a voltage threshold includes: performing proportional-integral processing on the difference between the target charging voltage of the DC power supply module and the current voltage to obtain an output current; performing current limiting processing on the output current to obtain a target current; performing proportional-integral processing on the difference between the target current and the current current of the DC power supply module to obtain a charging voltage; and calculating a charging duty cycle based on the charging voltage and the current voltage so that the bidirectional energy converter can adjust the charging current according to the charging duty cycle, thereby enabling the AC power supply module to charge the DC power supply module.

[0067] Specifically, the charging duty cycle is the ratio of the on-time of the switching transistor in the bidirectional energy converter to the switching cycle. The bidirectional energy converter adjusts the charging current according to the charging duty cycle, enabling the AC power supply module to charge the DC power supply module. The charging target voltage is a pre-set target voltage to be achieved during the charging process.

[0068] For example, Figure 5 This is a schematic diagram of a charging control strategy for a bidirectional energy converter according to an embodiment of this application. Figure 5 As shown, the target charging voltage of the DC power supply module is... The current voltage of the DC power supply module sampled by the bidirectional energy converter. Perform differential processing to obtain the voltage deviation. The current is then input to a voltage PI controller for PI processing to obtain the output current. The output current is then input to a current limiter for current limiting to obtain the target current in the current loop. Then the target current and the current sampled by the bidirectional energy converter Perform differential processing to obtain the current deviation. The input is then fed into a current PI controller for PI processing to obtain the charging voltage. Based on this charging voltage and the current voltage, the charging duty cycle is calculated. This allows the bidirectional energy converter to adjust the charging current according to the duty cycle, enabling the AC power supply unit in the AC power supply module to charge the DC power supply unit in the DC power supply module until the voltage exceeds a voltage threshold, at which point the DC power supply module is reconnected to the grid for discharge. The current limiter, voltage PI controller, and current PI controller are virtual control algorithms implemented through software design or digital logic, and their functions depend on physical hardware (such as the bidirectional energy converter).

[0069] In this way, the bidirectional energy converter limits the charging voltage to the DC power supply module through the voltage loop and dynamically controls the charging current supplied to the DC power supply module through the current loop, thereby protecting the DC power supply module and realizing automatic charging of the DC power supply module from the AC power supply module, thus preventing the DC power supply module from over-discharging.

[0070] In some embodiments, the power distribution method based on bus voltage regulation further includes: performing proportional-integral processing on the difference between the rated voltage and the current voltage to obtain the output current; and calibrating the output current to obtain the output duty cycle, so that the constant voltage rectifier controls the voltage of the current bus at the rated voltage according to the output duty cycle.

[0071] For example, Figure 6 This is a schematic diagram illustrating the constant voltage control strategy of a constant voltage rectifier according to an embodiment of this application. Figure 6As shown, the constant voltage rectifier controls the bus voltage at the rated voltage through this constant voltage control strategy, and the second power adjustment unit of the constant voltage rectifier can adaptively adjust the adjusted voltage after the first power adjustment unit of the bidirectional energy converter adjusts the bus voltage through this constant voltage control strategy, so as to stabilize it at the rated voltage.

[0072] like Figure 6 As shown, the rated voltage of the busbar and the current voltage sampled Perform differential processing to obtain the voltage deviation. The current is then input to a voltage PI controller for PI processing to obtain the output current. The voltage PI controller then undergoes calibration (the process of converting the current signal output by the voltage PI controller into a usable duty cycle command) to obtain the output duty cycle. The second power adjustment unit of the constant voltage rectifier controls the on-time of different switching transistors based on the output duty cycle to maintain the current voltage at the rated voltage. The voltage PI controller is a virtual control algorithm implemented through software design or digital logic, and it relies on physical hardware (such as the constant voltage rectifier) ​​to execute its functions.

[0073] In summary, according to the power distribution method based on bus voltage regulation provided in this application, the first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on the comparison between the actual output power and the maximum output power of the DC power supply module. This allows the second power adjustment unit to automatically adjust the voltage output from the AC power supply module to the bus to the rated voltage after detecting that the bus voltage has been adjusted. This enables the redistribution of power in the system. The entire system does not require communication between the central controller and the local controller, reducing the dynamic response time of the system and thus improving the system's responsiveness.

[0074] The steps described above are for clarity only. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this application.

[0075] Furthermore, the examples mentioned in the above embodiments can be freely combined, and any combination can be understood as an embodiment. The terms "embodiment" or "example" appearing in various locations in the specification do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0076] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0077] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0078] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the above-described embodiment of the power distribution method based on bus voltage regulation.

[0079] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0080] In the embodiments of this application, the first power adjustment unit dynamically adjusts the voltage output from the DC power supply module to the bus based on a comparison between the actual output power and the maximum output power of the DC power supply module. This allows the second power adjustment unit to automatically adjust the voltage output from the AC power supply module to the bus to the rated voltage upon detecting an adjustment in the bus voltage. This enables power redistribution within the system, eliminating the need for communication between the central controller and local controllers, reducing dynamic response time and improving system responsiveness. It is readily apparent that this embodiment is a method embodiment corresponding to the system embodiment described above, and this embodiment can be implemented in conjunction with the system embodiment described above. The relevant technical details mentioned in the system embodiments described above remain valid in this embodiment, and will not be repeated here to avoid repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the system embodiments described above.

[0081] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A power distribution system based on bus voltage regulation, characterized in that, It includes a DC power supply module and an AC power supply module, which are connected to the load via the same bus. The DC power supply module includes a first power adjustment unit, which is disposed in the bidirectional energy converter of the DC power supply module. The first power adjustment unit is used to adjust the voltage output by the DC power supply module to the bus according to the actual output power of the DC power supply module and the preset maximum output power. The AC power supply module includes a second power adjustment unit, which is configured in the constant voltage rectifier of the AC power supply module. The second power adjustment unit is used to adjust the voltage output from the AC power supply module to the bus to the rated voltage after detecting that the voltage of the bus has been adjusted, so as to realize the output power distribution between the DC power supply module and the AC power supply module.

2. The power distribution system based on bus voltage regulation according to claim 1, characterized in that, The first power adjustment unit is specifically used to: compare the actual output power of the DC power supply module with the maximum output power, and when the actual output power is greater than the maximum output power, the first power adjustment unit reduces the voltage output by the DC power supply module to the bus.

3. The power distribution system based on bus voltage regulation according to claim 2, characterized in that, The first power adjustment unit is specifically used to: when the actual output power is less than the maximum output power, the first power adjustment unit increases the voltage output by the DC power supply module to the bus.

4. The power distribution system based on bus voltage regulation according to claim 2, characterized in that, The DC power supply module includes a DC power supply unit and a bidirectional energy converter. The DC power supply unit is connected to the input side of the bidirectional energy converter, and the output side of the bidirectional energy converter is connected to the load through the bus. The AC power supply module includes an AC power supply unit and a constant voltage rectifier. The AC power supply unit is connected to the input side of the constant voltage rectifier, and the output side of the constant voltage rectifier is connected to the load through the bus.

5. A power distribution method based on bus voltage regulation, characterized in that, The method is applied to a power distribution system based on bus voltage regulation. The system includes a DC power supply module and an AC power supply module. The DC power supply module and the AC power supply module are connected to the load through the same bus. The bidirectional energy converter of the DC power supply module is equipped with a first power adjustment unit, and the constant voltage rectifier of the AC power supply module is equipped with a second power adjustment unit. The first power adjustment unit in the DC power supply module adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and the preset maximum output power; After detecting that the voltage of the bus has been adjusted, the second power adjustment unit in the AC power supply module adjusts the voltage output from the AC power supply module to the bus to the rated voltage, so as to realize the output power distribution between the DC power supply module and the AC power supply module.

6. The power distribution method based on bus voltage regulation according to claim 5, characterized in that, Before the first power adjustment unit of the DC power supply module adjusts the voltage output from the DC power supply module to the bus based on the actual output power of the DC power supply module and the preset maximum output power, the method further includes: The bidirectional energy converter in the DC power supply module samples the voltage of the DC power supply module; When the voltage is greater than the voltage threshold of the DC power supply module, the bidirectional energy converter enters a discharge mode so as to supply power to the load through the DC power supply module; When the voltage is less than the voltage threshold of the DC power supply module, the bidirectional energy converter enters a charging mode to charge the DC power supply module through the AC power supply module until the voltage is greater than the voltage threshold.

7. The power distribution method based on bus voltage regulation according to claim 5, characterized in that, The adjustment of the voltage output from the DC power supply module to the bus includes: The difference between the actual output power and the maximum output power is subjected to proportional-integral processing to obtain the power output signal; The discharge current is obtained by performing proportional-integral processing on the power output signal and the difference between the current voltage and the target voltage. The difference between the discharge current and the current current of the DC power supply module is processed by proportional-integral processing to obtain the discharge voltage. The discharge duty cycle is calculated based on the discharge voltage and the current voltage so that the first power adjustment unit can adjust the voltage output from the DC power supply module to the bus according to the discharge duty cycle.

8. The power distribution method based on bus voltage regulation according to claim 6, characterized in that, The step of charging the DC power supply module through the AC power supply module until the voltage is greater than the voltage threshold includes: The output current is obtained by performing proportional-integral processing on the difference between the target charging voltage of the DC power supply module and the current voltage. The output current is current-limited to obtain the target current; The difference between the target current and the current current of the DC power supply module is processed by proportional-integral processing to obtain the charging voltage. The charging duty cycle is calculated based on the charging voltage and the current voltage, so that the bidirectional energy converter can adjust the charging current according to the charging duty cycle, so that the AC power supply module can charge the DC power supply module.

9. The power distribution method based on bus voltage regulation according to claim 5, characterized in that, The method further includes: The output current is obtained by performing proportional-integral processing on the difference between the rated voltage and the current voltage. The output current is calibrated to obtain the output duty cycle, so that the constant voltage rectifier in the DC power supply module can control the voltage of the current bus at the rated voltage according to the output duty cycle.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the power distribution method based on bus voltage regulation as described in any one of claims 5 to 9.

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