Microgrid system and control method thereof

Abstract

The invention relates to the technical field of electric power, in particular to a micro-grid system and a control method thereof. The micro-grid system comprises a power generation device and a first voltage acquisition device deployed on the side of the power generation device, and the power generation device is configured to improve power output in response to the fact that the bus voltage detected by the first voltage acquisition device is lower than rated voltage; the second voltage acquisition device is deployed on the side of the energy storage device, and the energy storage device is configured to determine a working mode according to the bus voltage detected by the second voltage acquisition device.

Description

Technical Field

[0001] The present disclosure relates to the field of electric power technology, and in particular to a microgrid system and a control method thereof. Background Art

[0002] A microgrid is a small power generation and distribution system. By building a microgrid system outside the main power grid for local power sources, it can effectively realize the flexible and efficient application of distributed power sources and solve the problem of grid connection of a large number of distributed power sources in various forms.

[0003] As people gradually increase the utilization rate of renewable resources, photovoltaic power generation, wind power generation, etc. are widely used and promoted. Therefore, more and more microgrid systems have photovoltaic power generation or wind power generation as power sources. Due to the instability of renewable resource power generation, microgrid systems including renewable resource power generation devices usually also need to have energy storage devices.

[0004] In the related art, when using the integrated power generation and energy storage microgrid system, it is necessary to establish communication interconnection between multiple devices in the microgrid system, and send instructions through the control device to achieve response scheduling between multiple devices. In the above scheme, in the process of using the instructions of the control device to control, the communication overhead between the devices in the microgrid system is large, which is easily interfered and has a large delay. Summary of the invention

[0005] The microgrid system in the related art has the problem that communication is susceptible to interference and has large delays.

[0006] In view of this, the present disclosure provides a microgrid system that can effectively solve the above problems.

[0007] According to one aspect of the present disclosure, a microgrid system is proposed, comprising: a power generation device and a first voltage acquisition device deployed on the power generation device side, the power generation device being configured to increase power output in response to a bus voltage detected by the first voltage acquisition device being lower than a rated voltage; an energy storage device and a second voltage acquisition device deployed on the energy storage device side, the energy storage device being configured to determine an operating mode according to the bus voltage detected by the second voltage acquisition device.

[0008] In the technical solution in the embodiments of the present disclosure, the microgrid system is controlled by each device based on the bus voltage detected by the voltage acquisition device, reducing the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing interference and delay in the microgrid system.

[0009] In some embodiments, the power generation device is further configured to: when the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than a first threshold, switch the power generation mode to a maximum power output mode to increase power output.

[0010] In the technical solution in the embodiments of the present disclosure, by additionally setting a first threshold, it is further limited that when the bus voltage is lower than the rated voltage by more than the first threshold, the power generation device switches to maximum power output, thereby avoiding misjudgment caused by voltage fluctuations, and by directly switching to maximum power output, the microgrid system can alleviate the bus voltage reduction to the greatest extent, thereby improving the stability of the microgrid system.

[0011] In some embodiments, the energy storage device is further configured to: in response to the bus voltage being lower than the rated voltage, wait for a first time delay, and determine an operating mode based on a comparison between the bus voltage and the rated voltage.

[0012] In the technical solution in the embodiment of the present disclosure, the energy storage device is specifically limited to wait for a first delay after detecting that the bus voltage is lower than the rated voltage, and then determine the working mode based on the comparison between the bus voltage and the rated voltage. The above process allows the energy storage device to determine whether the power generation device increases the power output based on the bus voltage, without the need for communication, thereby reducing interference and delays in the microgrid system. In the case where it is determined that the power generation device increases the power output, it waits for a period of time before determining whether the bus power supply has returned to normal, and determines the working mode based on the bus voltage, thereby avoiding conflicts in the additional power supply of the power generation device and the energy storage device, and realizing the flexible response of the microgrid system.

[0013] In some embodiments, the energy storage device is further configured to: determine that the operating mode is the charging mode when the bus voltage is not lower than the rated voltage, or when the bus voltage is lower than the rated voltage but the difference between the bus voltage and the rated voltage is less than a second threshold; and determine the operating mode according to the charge state of the energy storage device when the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than the second threshold.

[0014] In the technical solution in the embodiment of the present disclosure, by additionally setting a second threshold, it is further limited to the case where the bus voltage is not lower than the rated voltage or the degree to which the bus voltage is lower than the rated voltage is less than the second threshold, in which the bus voltage is judged to have returned to normal and the energy storage device continues to charge, thereby avoiding misjudgment due to voltage fluctuations and output conflicts between the energy storage device and the power generation device, thereby improving the stability of the microgrid system.

[0015] In some embodiments, the energy storage device is further configured to: when the state of charge of the energy storage device is less than the energy storage threshold, determine the working mode to be the charging mode; when the state of charge of the energy storage device is greater than the energy storage threshold, determine the working mode to be the discharging mode.

[0016] In the technical solution in the embodiment of the present disclosure, by setting an energy storage threshold and judging whether the energy storage device is to discharge according to the energy storage threshold, the system can have a minimum backup energy source, thereby ensuring the safe operation of the microgrid system and improving the stability of the microgrid system.

[0017] In some embodiments, the microgrid system further includes: a load device and a third voltage acquisition device deployed on the load device side, wherein the load device is configured to adjust operating power according to the bus voltage detected by the third voltage acquisition device.

[0018] In the technical solution in the embodiment of the present disclosure, the load device is also controlled according to the bus voltage, which reduces the communication overhead between the various devices in the microgrid system, thereby reducing the interference and delay in the communication in the microgrid system.

[0019] In some embodiments, the load device is further configured to: in response to the bus voltage being lower than the rated voltage, wait for a second time delay, and reduce operating power if the bus voltage is still lower than the rated voltage.

[0020] In the technical solution in the embodiment of the present disclosure, the load device is specifically limited to wait for the second delay after detecting that the bus voltage is lower than the rated voltage, and then determine whether to reduce the operating power based on the comparison between the bus voltage and the rated voltage. The above process allows the energy storage device to determine whether the power generation device increases the power output based on the bus voltage, without the need for communication, thereby reducing interference and delays in the microgrid system. In the case where it is determined that the power generation device increases the power output, it waits for a period of time before determining whether the bus power supply has returned to normal, and determines the working mode based on the bus voltage, thereby avoiding conflicts in the additional power supply of the power generation device and the energy storage device, and realizing the flexible response of the microgrid system.

[0021] The above process allows the load device to determine whether the power generation device increases power output and whether the energy storage device has completed the work mode based on the bus voltage, without the need for communication, reducing interference and delay in the microgrid system. After the power generation device increases power output and the energy storage device determines the work mode, it waits for a period of time before determining whether the bus power supply has returned to normal, and determines whether to reduce the operating power based on the bus voltage, avoiding the load device still reducing the operating power when the power generation device and energy storage device can restore the bus voltage to normal, and realizing the flexible response of the microgrid system.

[0022] In some embodiments: the first voltage acquisition device includes a first integration circuit; the second voltage acquisition device includes a second integration circuit; the power generation device includes a first voltage converter; and the energy storage device includes a second voltage converter.

[0023] In the technical solution in the embodiments of the present disclosure, through the integration circuit and the voltage converter, the voltage acquisition circuit in the power generation device and the energy storage device can detect the changes in the bus voltage over a period of time, and adjust the input / output power through the voltage converter according to the bus voltage, thereby improving the flexibility response capability of the microgrid system.

[0024] In some embodiments, the third voltage acquisition device includes a third integration circuit; and the load device includes a third voltage converter.

[0025] In the technical solution in the embodiment of the present disclosure, through the integration circuit and the voltage converter, the voltage acquisition circuit in the load device can detect the change of voltage over a period of time, and adjust the input power through the voltage converter, thereby improving the flexibility response capability of the microgrid system.

[0026] According to another aspect of the present disclosure, a control method is proposed, which is applied to a microgrid system as described in any one of the above items, including: the power generation device increases power output in response to the bus voltage detected by the first voltage acquisition device being lower than the rated voltage; the energy storage device determines the operating mode according to the bus voltage detected by the second voltage acquisition device.

[0027] In the technical solution in the embodiments of the present disclosure, the microgrid system is controlled by each device based on the bus voltage detected by the voltage acquisition device, reducing the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing interference and delay in the microgrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0029] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0030] Figure 1 is a block diagram illustrating a microgrid system according to some embodiments of the present disclosure;

[0031] Figure 2 is a schematic diagram showing the structure of a microgrid system according to some embodiments of the present disclosure;

[0032] Figure 3is a circuit diagram showing a voltage collection device according to some embodiments of the present disclosure;

[0033] Figure 4 is a flowchart showing a control method of a microgrid system in some embodiments of the present disclosure;

[0034] Figure 5 is a block diagram showing a microgrid system according to some other embodiments of the present disclosure;

[0035] Figure 6 is a flowchart showing the operation of a microgrid system according to some embodiments of the present disclosure;

[0036] Figure 7 is a schematic diagram showing the structure of a microgrid system according to other embodiments of the present disclosure;

[0037] Figure 8 is a block diagram illustrating a computer system for implementing some embodiments of the present disclosure.

[0038] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0039] Various embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps described in these embodiments should be interpreted as being merely illustrative and not as a limitation.

[0040] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0041] It should also be understood that any component, data or structure mentioned in the embodiments of the present disclosure can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0042] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0043] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0044] In a traditional microgrid system, control is performed using instructions from a control device. The communication overhead between devices in the microgrid system is large, and the system is susceptible to interference and has large delays.

[0045] In view of this, the present disclosure proposes a microgrid system, which can reduce communication interference and delay in the microgrid system.

[0046] First, combine Figure 1 A microgrid system in the present disclosure is described. Figure 1 is a block diagram illustrating a microgrid system according to some embodiments of the present disclosure.

[0047] like Figure 1 As shown, the microgrid system 1 includes: a power generation device 11 and a first voltage acquisition device 12 deployed on the side of the power generation device 110, wherein the power generation device 11 is configured to increase power output in response to the bus voltage detected by the first voltage acquisition device 12 being lower than the rated voltage; an energy storage device 21 and a second voltage acquisition device 22 deployed on the side of the energy storage device 21, wherein the energy storage device 21 is configured to determine an operating mode according to the bus voltage detected by the second voltage acquisition device 22.

[0048] The power generation device 11 may include, for example, a traditional power generation device such as a diesel generator, or may include a renewable power generation device such as a photovoltaic power generation device and a wind power generation device.

[0049] The energy storage device 21 may include, for example, a compressed air energy storage system (CAESS), a flywheel energy storage system (FESS), or a battery such as a fuel cell or a flow battery. The energy storage device 21 may store energy when power demand is low and release energy during peak power demand periods to help balance the load on the power grid. Accordingly, the working modes of the energy storage device include a charging mode and a discharging mode.

[0050] In the above embodiment, the power generation device 11 and the energy storage device 21 are controlled according to the bus voltages detected by the first voltage acquisition device 12 and the second voltage acquisition device 22 respectively. No communication is required between the power generation device 11 and the energy storage device 21, thereby reducing communication overhead.

[0051] Reference below Figure 2 The structure of the microgrid system in the embodiment of the present disclosure is further introduced. Figure 2 is a schematic diagram showing the structure of a microgrid system according to some embodiments of the present disclosure.

[0052] like Figure 2 As shown, in the microgrid system 1 , the power generation device 11 and the first voltage collection device 12 are deployed in one branch of the bus 10 , and the energy storage device 21 and the second voltage collection device 22 are deployed in another branch of the bus 10 .

[0053] like Figure 2 As shown, in some embodiments, the power generation device 11 may further include a first voltage converter 111 , and the energy storage device 21 may further include a second voltage converter 211 .

[0054] The first voltage converter 111 and the second voltage converter 211 include, for example, a DC / DC voltage converter or a DC / AC voltage converter.

[0055] Through the voltage converter, the energy storage device 21 can adjust the voltage across the voltage converter and switch between working modes. In addition, the power generation device 11 and the energy storage device 21 can also adjust the power of the output or input electric energy by adjusting the voltage across the voltage converter.

[0056] Figure 2 The deployment of the first voltage collection device 12 and the second voltage collection device 22 shown is only exemplary, and the technical solution disclosed in the present invention does not limit the deployment of the first voltage collection device 12 and the second voltage collection device 22. For example, the first voltage collection device 12 can be deployed in parallel on the side of the power generation device 11, such as Figure 2 As shown, it can also be deployed between the power generation device 11 and the busbar 10, or integrated into the power generation device 11, etc.

[0057] The first voltage acquisition device 12 detects the bus voltage and sends the detected voltage to the power generation device 11 , and the second voltage acquisition device 22 also detects the bus voltage and sends the detected voltage to the energy storage device 21 .

[0058] In some embodiments, the circuit diagram of the voltage collection device is as follows: Figure 3 shown. Figure 3 is a circuit diagram showing a voltage collection device according to some embodiments of the present disclosure.

[0059] Figure 3 The voltage acquisition device 3 is divided into three parts: a voltage divider circuit 31 composed of multiple resistors and capacitors; an integration circuit 32 composed of capacitors, resistors, and operational amplifiers; and a processing circuit 33 composed of capacitors, resistors, and a digital signal processor.

[0060] like Figure 3 As shown, the voltage divider circuit 31 is composed of resistors R211 to R218, R221 to R223, and capacitor C192. By connecting multiple resistors in series, the voltage divider circuit 31 can make the voltage input to the subsequent integration circuit 32 and the processing circuit 33 only a part of the bus voltage. For example, in this embodiment, the voltage input to the integration circuit 32 is one sixth of the bus voltage, thereby preventing the bus voltage from being too high and causing damage to the integration circuit 32.

[0061] The integration circuit 32 is composed of a capacitor C191, a resistor R220 and an operational amplifier 200. Through such an integration circuit, the input voltage signal can be converted into an output current proportional to its time integral, thereby realizing the monitoring of the bus voltage change within a period of time.

[0062] The processing circuit 33 is composed of a resistor R219, a capacitor C190 and a digital signal processor V_BUS_DSP, and is used to process the output of the integration circuit 32 to obtain the bus voltage.

[0063] The first voltage acquisition device 12 and the second voltage acquisition device 22 can be, for example, Figure 3 In some embodiments, the first voltage acquisition device 12 includes a first integration circuit, and the second voltage acquisition device 22 includes a second integration circuit. Through the integration circuit, the voltage acquisition device can detect the change of the bus voltage over a period of time, avoid misjudgment caused by instantaneous fluctuations in the bus voltage, and improve the flexibility response capability of the microgrid system.

[0064] In the above embodiment, when the power generation device 11 detects that the bus voltage is lower than the rated voltage, it can increase the power output to try to increase the bus voltage and restore the bus voltage to normal. The energy storage device 21 will also determine whether the supply and demand in the microgrid system are restored to balance according to the bus voltage and perform corresponding control.

[0065] In the microgrid system shown in the above-mentioned embodiment of the present disclosure, each device performs its own control based on the bus voltage detected by the voltage acquisition device, thereby reducing the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing interference and delay in the microgrid system.

[0066] Based on the above Figures 1 to 3The basic structure of the microgrid system disclosed in this disclosure is introduced. Figure 4 The control method of the microgrid system in some embodiments of the present disclosure is introduced, and the control method is used to show how to achieve flexible response without the need for communication between the power generation device and the energy storage device.

[0067] Figure 4 is a flow chart showing a control method of a microgrid system in some embodiments of the present disclosure. Figure 4 As shown, the control method of the microgrid system includes steps S41 to S42.

[0068] Under certain circumstances, the bus voltage may decrease. For example, when a main grid failure occurs, the grid devices connected to the main grid in the microgrid system will limit the output power of the main grid, resulting in a decrease in the bus voltage.

[0069] In step S41, the power generation device increases power output in response to the bus voltage detected by the first voltage acquisition device being lower than the rated voltage. Figure 4 In the embodiment described above, the rated voltage is, for example, 400V.

[0070] Specifically, the power generation device can be further configured to: when the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than a first threshold, switch the power generation mode to a maximum power output mode to increase power output.

[0071] By additionally setting a first threshold, it is further limited that when the bus voltage is lower than the rated voltage by more than the first threshold, the power generation device switches to maximum power output, thereby avoiding misjudgment caused by voltage fluctuations. By directly switching to maximum power output, the microgrid system can alleviate the bus voltage reduction to the greatest extent, thereby improving the stability of the microgrid system.

[0072] The first threshold is, for example, 3V. bus When it drops below 400V-3V, the power generation device determines that an abnormality has occurred and switches the power generation mode to the maximum power output mode to increase the power output, thereby increasing the bus voltage.

[0073] In step S42, the energy storage device determines an operating mode according to the bus voltage detected by the second voltage acquisition device.

[0074] In some embodiments, the energy storage device may be further configured to: in response to the bus voltage being lower than the rated voltage, wait for a first time delay, and determine an operating mode based on a comparison between the bus voltage and the rated voltage.

[0075] In the above embodiment, the energy storage device is specifically limited to wait for the first delay after detecting that the bus voltage is lower than the rated voltage, and then determine the working mode based on the comparison between the bus voltage and the rated voltage. The above process can enable the energy storage device to determine whether the power generation device increases the power output based on the bus voltage without communication, thereby reducing interference and delay in the microgrid system.

[0076] When the energy storage device determines that the power generation device increases its power output, it waits for a period of time before determining whether the bus power supply has returned to normal, and determines the working mode based on the bus voltage. This can avoid the energy storage device still judging that the bus voltage is abnormal when the power generation device increases its power output and can restore the bus voltage, thereby realizing the flexible response of the microgrid system.

[0077] For example, when the bus voltage V bus When the voltage drops to 380V, which is lower than the rated voltage of 400V, the first voltage acquisition device and the second voltage acquisition device will detect that the bus voltage is lower than the rated voltage. At this time, the power generation device increases the power output in response to the bus voltage detected by the first voltage acquisition device being lower than the rated voltage.

[0078] If the energy storage device also determines the working mode according to the bus voltage at this time, for example, it is determined to be the discharge mode, which may cause the power in the bus to be too high, which in turn affects the stability of the microgrid system. By setting the energy storage device to wait for a period of time before determining whether the bus power supply has returned to normal when it determines that the power generation device has increased its power output, and determining the working mode based on the bus voltage, the above situation can be effectively avoided, thereby achieving a flexible response of the microgrid system.

[0079] The process of determining the working mode of the energy storage device based on the comparison between the bus voltage and the rated voltage may specifically include: determining that the working mode is the charging mode when the bus voltage is not lower than the rated voltage, or when the bus voltage is lower than the rated voltage but the difference between the bus voltage and the rated voltage is less than a second threshold value; and determining the working mode according to the charge state of the energy storage device when the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than a second threshold value.

[0080] By additionally setting a second threshold, it is further limited that when the bus voltage is not lower than the rated voltage or the degree to which the bus voltage is lower than the rated voltage is less than the second threshold, it is judged that the bus voltage has returned to normal, and the energy storage device continues to charge until the charging is completed, that is, the charge state of the energy storage device reaches 100%.

[0081] The above configuration avoids misjudgment caused by voltage fluctuations and output conflicts between the energy storage device and the power generation device, thereby improving the stability of the microgrid system.

[0082] In a further embodiment, the energy storage device determines the working mode according to the charge state, specifically including: when the charge state of the energy storage device is less than the energy storage threshold, determining the working mode as the charging mode; when the charge state of the energy storage device is greater than the energy storage threshold, determining the working mode as the discharging mode.

[0083] The energy storage threshold of the energy storage device is, for example, 20%. When the state of charge of the energy storage device is higher than the energy storage threshold, it can be considered that the energy storage device has sufficient electrical energy for output, the working mode can be determined to be the discharge mode, and the auxiliary bus voltage returns to normal.

[0084] When the state of charge of the energy storage device is lower than the energy storage threshold, it is necessary to first ensure that the energy storage device has a minimum amount of electrical energy, thereby ensuring the safe operation of the microgrid system in an emergency and improving the stability of the microgrid system.

[0085] Combined with the above Figure 4 The control method of the microgrid system in the embodiment of the present disclosure is introduced. The power generation device and the energy storage device in the microgrid system proposed by the present disclosure can be controlled separately without communication, and the control status of the other device is judged according to the bus voltage, which reduces the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing the interference and delay in the microgrid system. Figure 5 The microgrid system in other embodiments of the present disclosure is introduced. Figure 5 is a block diagram showing a microgrid system according to some other embodiments of the present disclosure.

[0086] like Figure 5 As shown, the microgrid system 1' comprises a power generation device 11' and a first voltage acquisition device 12', an energy storage device 21' and a second voltage acquisition device 22', a load device 31' and a third voltage acquisition device 32'. Among them, the power generation device 11' is similar to the power generation device 11, the first voltage acquisition device 12' is similar to the first voltage acquisition device 12, the energy storage device 21' is similar to the energy storage device 21, and the second voltage acquisition device 22' is similar to the second voltage acquisition device 22, which will not be described here, and the load device 31' and the third voltage acquisition device 32' will be described in detail below.

[0087] The third voltage acquisition device 32' in the microgrid system 1' is deployed on the load device 32' side, and the load device 32' is configured to adjust the operating power according to the bus voltage detected by the third voltage acquisition device.

[0088] In the above embodiment, the load device 32' is also controlled according to the bus voltage, which further reduces the communication overhead between the various devices in the microgrid system, thereby reducing the interference and delay received by the communication in the microgrid system.

[0089] Similar to the power generation device, energy storage device, first voltage acquisition device, and second voltage acquisition device in the above described embodiments, the load device 31' may also include a third voltage converter, and the third voltage acquisition device 32' may also include a third integration circuit.

[0090] Through the integration circuit and the voltage converter, the voltage acquisition circuit in the load device can detect the change of voltage over a period of time, and adjust the input power through the voltage converter, thereby improving the flexibility response capability of the microgrid system.

[0091] The load device 31 ′ may include a DC load and / or an AC load. According to the type of the load included in the load device 31 ′ and the voltage type of the bus, the third voltage converter may include a DC / DC voltage converter and / or an AC / DC voltage converter.

[0092] In some embodiments, the load device 31 ′ may also be further configured to: in response to the bus voltage being lower than the rated voltage, wait for a second time delay, and reduce the operating power when the bus voltage is still lower than the rated voltage.

[0093] The second time delay is, for example, equal to the first time delay, or the second time delay may be greater than the first time delay, so that the load device can wait for a period of time after the energy storage device determines the working mode, and then determine whether the bus voltage returns to normal.

[0094] The above process enables the load device to determine whether the power generation device increases power output and whether the energy storage device completes the determined working mode based on the bus voltage, without the need for communication, thereby reducing interference and delay in the microgrid system.

[0095] After the power generation device increases its power output and the energy storage device determines its working mode, the load device waits for a while before determining whether the bus power supply has returned to normal, and determines whether to reduce the operating power based on the bus voltage. This avoids the situation where the load device still reduces the operating power when the power generation device and the energy storage device can restore the bus voltage to normal, thereby achieving a flexible response of the microgrid system.

[0096] Combined with the above Figures 1 to 5 The basic structure of the microgrid system and the operation process of each device are introduced separately. Figure 6 and Figure 7 The microgrid system and its operation process in some embodiments of the present disclosure are introduced. Figure 6 is a flowchart showing the operation of a microgrid system according to some embodiments of the present disclosure. Figure 7 is a schematic diagram showing the structure of a microgrid system according to some other embodiments of the present disclosure.

[0097] like Figure 6 As shown, the operation process of the microgrid system includes steps S61 to S68.

[0098] In step S61, the bus voltage V bus Reduce, specifically, in special circumstances such as a main grid failure, the bus voltage is reduced.

[0099] In step S62, the power generation device responds to the bus voltage V detected by the first voltage acquisition device. bus When the voltage is lower than the rated voltage of 400V and the difference with 400V is greater than 3V, it switches to the maximum power output mode.

[0100] The generator can be the first to respond to a decrease in the bus voltage by switching to maximum power output mode, ie increasing power output.

[0101] In step S63, the energy storage device waits for 5 seconds and then sends the bus voltage V detected by the second voltage acquisition device to the bus Compare with 400V, and determine the working mode based on the comparison result.

[0102] In step S64, the result of the comparison in step S63 is the bus voltage V bus When the voltage is not less than 400V or the difference with 400V is less than 3V, the working mode is determined to be the charging mode, and the energy storage device is charged until it reaches 100% charge state.

[0103] In step S65, the result of the comparison in step S63 is the bus voltage V bus When the voltage is less than 400V and the difference from 400V is greater than 3V, the state of charge is compared with the energy storage threshold of 20%.

[0104] In step S66, when the result of the comparison in step S65 is that the state of charge is greater than the energy storage threshold, the operating mode is determined to be the discharge mode. After the discharge, the microgrid system can perform cyclic monitoring on the bus voltage until the bus voltage returns to normal.

[0105] In step S67, when the result of the comparison in step S65 is that the state of charge is less than the energy storage threshold, the operating mode is determined to be the charging mode until the state of charge reaches 20%.

[0106] The energy storage device can determine whether to discharge through the above steps, and secondly respond to the reduction of the bus voltage.

[0107] In step S68, after the energy storage device determines the working mode, the load device determines whether the operating power needs to be reduced according to the bus voltage.

[0108] The load devices may respond to the reduction in bus voltage by determining whether to reduce operating power or a third one.

[0109] Through the above-mentioned microgrid system operation process, the microgrid system is controlled by each device based on the bus voltage detected by the voltage acquisition device, which reduces the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing interference and delay in the microgrid system.

[0110] Figure 7 is a complete structural diagram showing a microgrid system according to some embodiments of the present disclosure.

[0111] like Figure 7 As shown, the complete structure of the microgrid system 1'' that executes the above complete process may include: a power generation device 11'' and a first voltage acquisition device 12'', an energy storage device 21'' and a second voltage acquisition device 22'', a load device 31'' and a third voltage acquisition device 32'', and a grid device 34''.

[0112] Among them, the power generation device 11'', the first voltage collection device 12'', the energy storage device 21'', the second voltage collection device 22'', the load device 31'' and the third voltage collection device 32'' can perform the following steps: Figure 6 The complete process of the flexibility response of the microgrid system in the described embodiment.

[0113] The power generation device 11 ″ specifically includes a first voltage converter 111 ″, the energy storage device 21 ″ specifically includes a second voltage converter 211 ″, and the load device 31 ″ specifically includes a third voltage converter 311 ″.

[0114] The grid device 34 ″ is a device for connecting the microgrid system to the main grid. The specific implementation is not limited. For example, the microgrid system and the main grid can be connected through a voltage converter or the like to realize power exchange between the grids.

[0115] Figure 7 In the microgrid system shown, each device performs its own control based on the bus voltage detected by the voltage acquisition device, which reduces the communication overhead required to achieve the flexible response of the microgrid system, thereby reducing interference and delay in the microgrid system.

[0116] Figure 8 is a block diagram illustrating a computer system for implementing some embodiments of the present disclosure.

[0117] like Figure 8 As shown, the computer system 8 may be in the form of a general purpose computing device. The computer system 8 includes a memory 81, a processor 82, and a bus 80 that connects the various system components.

[0118] The memory 81 may be a computer-readable storage medium in various forms, such as a system memory, a non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application program, a boot loader (BootLoader), and other programs. The system memory may include a volatile storage medium, such as a random access memory (RAM) and / or a cache memory. The non-volatile storage medium may store, for example, instructions for executing the corresponding embodiment of the control method. The non-volatile storage medium includes, but is not limited to, a disk storage, an optical storage, a flash memory, etc.

[0119] The processor 82 may be implemented by a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gates or transistors, and other discrete hardware components. Accordingly, each module may be implemented by a central processing unit (CPU) running instructions in a memory that execute corresponding steps, or by a dedicated circuit that executes corresponding steps.

[0120] The bus 80 may use any of a variety of bus architectures, including, but not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, and a Peripheral Component Interconnect (PCI) bus.

[0121] The computer system 8 may also include an input / output interface 83, a network interface 84, a storage interface 85, etc. These interfaces 83, 84, 85, the memory 81, and the processor 82 may be connected via a bus 80. The input / output interface 83 may provide a connection interface for input / output devices such as a display, a mouse, and a keyboard. The network interface 84 may provide a connection interface for various networked devices. The storage interface 85 may provide a connection interface for external storage devices such as a floppy disk, a USB flash drive, and an SD card.

[0122] According to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, some embodiments of the present disclosure include a computer program product, which, when running on a computer, enables the computer to implement the control method described in any of the foregoing embodiments. The computer program product includes computer instructions carried on a computer-readable medium, and the computer instructions include program code for executing the method shown in the flowchart.

[0123] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0124] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A microgrid system, comprising: A power generation device and a first voltage collection device deployed on the side of the power generation device, wherein the power generation device is configured to increase power output in response to a bus voltage detected by the first voltage collection device being lower than a rated voltage; An energy storage device and a second voltage acquisition device deployed on the side of the energy storage device, wherein the energy storage device is configured to determine an operating mode according to a bus voltage detected by the second voltage acquisition device.

2. The microgrid system according to claim 1, wherein: The power generation device is further configured as: When the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than a first threshold, the power generation mode is switched to a maximum power output mode to increase power output.

3. The microgrid system according to claim 1, wherein: The energy storage device is further configured as: In response to the bus voltage being lower than the rated voltage, after waiting for a first time delay, an operating mode is determined based on a comparison between the bus voltage and the rated voltage.

4. The microgrid system according to claim 3, wherein: The energy storage device is further configured as: When the bus voltage is not lower than the rated voltage, or the bus voltage is lower than the rated voltage but the difference between the bus voltage and the rated voltage is less than a second threshold, determining that the operating mode is the charging mode; When the bus voltage is lower than the rated voltage and the difference between the bus voltage and the rated voltage is greater than a second threshold, the operating mode is determined according to the charge state of the energy storage device.

5. The microgrid system according to claim 4, wherein: The energy storage device is further configured as: When the state of charge of the energy storage device is less than the energy storage threshold, determining that the working mode is a charging mode; When the state of charge of the energy storage device is greater than the energy storage threshold, the operating mode is determined to be the discharge mode.

6. The microgrid system according to claim 1, further comprising: A load device and a third voltage acquisition device deployed on the load device side, wherein the load device is configured to adjust the operating power according to the bus voltage detected by the third voltage acquisition device.

7. The microgrid system according to claim 6, wherein: The load device is further configured as: In response to the bus voltage being lower than the rated voltage, after waiting for a second time delay, the operating power is reduced when the bus voltage is still lower than the rated voltage.

8. The microgrid system according to claim 1, wherein: The first voltage acquisition device includes a first integration circuit; The second voltage acquisition device includes a second integration circuit; The power generation device includes a first voltage converter; The energy storage device includes a second voltage converter.

9. The microgrid system according to claim 6, wherein: The third voltage acquisition device includes a third integration circuit; The load device includes a third voltage converter.

10. A control method, applied to the microgrid system according to any one of claims 1 to 9, comprising: The power generation device increases power output in response to the bus voltage detected by the first voltage acquisition device being lower than the rated voltage; The energy storage device determines an operating mode according to the bus voltage detected by the second voltage acquisition device.

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