Multi-distributed power supply switching system and method

Abstract

The invention discloses a multi-distributed power supply switching system and method. The system comprises an electric input module, a first intelligent switching module, a second intelligent switching module, a timing module, a storage battery module and a multi-distributed power supply module, the commercial power input module is connected with the first intelligent switching module and is used for providing commercial power; the first intelligent switching module is connected with the second intelligent switching module, and is used for switching to the storage battery module to supply power to the load when receiving the commercial power outage instruction; the timing module is connected with the first intelligent switching module and is used for counting based on set time when the commercial power outage instruction is received, and sending a switching instruction when the counting time meets a first preset time threshold value; and the second intelligent switching module is connected with the multi-distributed power supply module and the storage battery module and is used for switching the storage battery module to the multi-distributed power supply module to supply power to the load when a secondary switching instruction is received, so that smooth switching among multiple power supplies can be realized, and the stability of power supply is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of distributed power supply, and in particular to a multi-distributed power switching system and method. Background Art

[0002] The multi-distributed power system combines multiple distributed power sources (such as renewable energy power generation devices like solar energy and wind energy) with the power grid, achieving the decentralization and diversification of power supply. In some medium and large-sized user-side owned distributed power systems, there are usually multiple types and numbers of mains power, storage batteries, and various distributed power sources. To ensure the normal power consumption of users, when the mains power fails, it is usually necessary to switch the power source to the storage battery or other distributed power sources to continue supplying power to at least a part of the load. For example, if the mains power fails, the power of the storage battery is supplied to the load. After a certain period of time, if the mains power does not resume, the distributed power source is started to further supply power to the load.

[0003] However, the traditional multi-power switching technology relies on complex power circuits and often faces the problem of difficult multi-power coordination during switching, resulting in an increased risk of power supply interruption and affecting the overall reliability of the system.

[0004] Therefore, it can be seen that how to achieve smooth switching of multiple distributed power sources and ensure the stability of coordinated power supply of distributed power sources has become an urgent technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention provides a multi-distributed power switching system and method to flexibly switch multiple distributed power sources in the face of medium and large-sized microgrid scenarios, and improve the overall reliability and stability of the power system by precisely managing and coordinating the power output and energy distribution of multiple distributed power sources.

[0006] To solve the above technical problems, an embodiment of the present invention provides a multi-distributed power switching system, including: Including: a mains power input module, a first intelligent switching module, a second intelligent switching module, a timing module, a storage battery module, and a multi-distributed power module composed of a plurality of power sources; The mains power input module is connected to the first intelligent switching module, and the mains power input module is used to provide mains power; The first intelligent switching module is connected to the second intelligent switching module, and the first intelligent switching module is used to disconnect the mains power and switch to the storage battery module to supply power to the load when receiving a mains power outage instruction; The timing module is connected to the first intelligent switching module. The timing module is configured to count based on a set time when receiving the power outage instruction of the mains power supply. When the counted time meets the first preset time threshold, a secondary switching instruction is sent. The second intelligent switching module is connected to the multi-distributed power supply module and the battery module. The second intelligent switching module is configured to switch the battery module to the multi-distributed power supply module to supply power to the load when receiving the secondary switching instruction.

[0007] Further: a first control unit and a first switching unit controlled by the first control unit, wherein, the first switching unit is connected to the mains power input module through the first control unit. When the mains power supply is cut off, the first control unit controls the disconnection / closure of corresponding contacts in the first switching unit, so that the power supply is switched to the battery module.

[0008] Further, the second intelligent switching module includes: a second control unit and a second switching unit controlled by the second control unit; When the count of the timing module reaches the first preset time threshold, the second control unit controls the disconnection / closure of corresponding contacts in the second switching unit, so that the power supply is switched from the battery module to the multi-distributed power supply module.

[0009] Further, when the power supply time of the multi-distributed power supply module meets the second preset time threshold, the multi-distributed power supply module is switched back to the battery module for power supply.

[0010] Further, the power supply of the timing module is supplied by the circuit connected between the load and the first intelligent switching module.

[0011] Further, the multi-distributed power supply module includes multiple distributed power supplies, supports dynamically increasing or decreasing the number of the distributed power supplies, and automatically switches when any one of the distributed power supplies fails.

[0012] Further, a master-slave cooperation module is further included, which is configured to designate one of the distributed power supplies as the master and the remaining distributed power supplies as slaves when multiple distributed power supplies are operating.

[0013] Further, when multiple distributed power supplies are operating, the slaves shield their autonomous operation functions and synchronize the parameters of the master and then perform grid-connected power supply.

[0014] Further, the master-slave cooperation module is configured to designate the master through an energy management system, hardware / software preset, or the slaves' real-time detection of grid characteristic fluctuations.

[0015] Another embodiment of the present invention provides a multi-distributed power switching method, which is applied to the above multi-distributed power switching system, and includes: The power state of the mains is monitored in real time through a voltage sensor. When a power outage of the mains is detected, a power switching process is triggered; In response to the power switching process instruction, the mains is disconnected and a timing module is started for countdown. The first contact corresponding to the battery input path in the first intelligent switching module is closed, so that the power supply of the load is switched from the mains to the battery module; When the timing module reaches the preset time threshold, the first contact is disconnected, and the second contact corresponding to the distributed power input path in the second switching unit is closed, so that the power supply of the load is switched from the battery module to the distributed power module; When it is monitored that the power supply of the distributed power module is interrupted, the first contact is re-closed, and the power supply is switched back to the battery module.

[0016] Compared with the prior art, the beneficial effects of the embodiments of the present invention are at least one of the following: The system of the present invention is composed of a mains input module, a first intelligent switching module, a second intelligent switching module, a timing module, a battery module and a multi-distributed power module composed of a plurality of power sources. The multi-distributed power module can uniformly manage and schedule each distributed power source, and through the combination of two groups of switching modules, while improving the overall energy efficiency of the system, it realizes a smooth switch from the battery to other distributed power sources when the mains power outage occurs, reduces the risk of power supply interruption, and improves the overall reliability of the system; the system supports the access and switching of multiple distributed power sources, enabling the system to flexibly adjust according to different energy demands and supply situations, and improving the adaptability and flexibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a multi-distributed power switching system in one embodiment of the present invention; Figure 2 is a schematic structural diagram of a multi-distributed power switching circuit in one embodiment of the present invention; Figure 3 is a schematic circuit diagram corresponding to the first control unit in one embodiment of the present invention; Figure 4 is a schematic circuit diagram corresponding to the second control unit in one embodiment of the present invention; Figure 5 is a schematic structural diagram of a multi-distributed power system based on Example 1 in one embodiment of the present invention; Figure 6It is a schematic flowchart of the master-slave collaborative operation based on Example 1 in one embodiment of the present invention; Figure 7 It is a schematic structural diagram of a multi-distributed power system based on Example 2 in one embodiment of the present invention; Figure 8 It is a schematic flowchart of the master-slave collaborative operation based on Example 2 in one embodiment of the present invention; Figure 9 It is a schematic structural diagram of a multi-distributed power system based on Example 3 in one embodiment of the present invention; Figure 10 It is a schematic flowchart of the master-slave collaborative operation of one based on Example 3 in one embodiment of the present invention; Figure 11 It is a schematic flowchart of the master-slave collaborative operation of another based on Example 3 in one embodiment of the present invention; Figure 12 It is a schematic flowchart of the multi-distributed power switching method in one embodiment of the present invention. Detailed implementation manners

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In the description of the present application, the terms "first", "second", "third", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0020] In the description of the present application, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. The terms "vertical", "horizontal", "left", "right", "up", "down" and similar expressions used herein are only for the purpose of illustration, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0021] In the description of the present application, it should be noted that, unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0022] It can be understood that when facing large and medium-sized microgrid systems and switching from a storage battery to other distributed power sources, since there may be multiple types and quantities of distributed power sources on the user side, such as new energy power stations, fuel cells, and small and micro hydropower, etc., how these distributed power sources cooperate and jointly supply power to the load stably requires corresponding cooperation strategies and control systems. Based on this, an embodiment of the present invention provides a multi-distributed power source switching system. Specifically, please refer to Figure 1 , Figure 1 which shows a schematic structural diagram of the multi-distributed power source switching system in one embodiment of the present invention.

[0023] It can be seen that the switching system includes: a first intelligent switching module M1, a second intelligent switching module M2, a storage battery module M3, a multi-distributed power source module M4 composed of a plurality of power sources, a timing module M5, and a mains input module M6.

[0024] The mains input module M6 is connected to the first intelligent switching module M1. In this embodiment, the mains input module M6 is mainly used to provide a mains power source, that is, when the mains power source is operating normally, it is used to supply power to the load.

[0025] The first intelligent switching module M1 is connected to the second intelligent switching module M2. The first intelligent switching module M1 is configured to disconnect the connection path between the mains power and the load when receiving a mains power outage instruction, and switch the power supply from the mains power to the battery module M3 to supply power to the load. In this embodiment, the battery module M3 is composed of corresponding batteries and is mainly used to supply power as an emergency power source when the mains power is out. It should be noted that in some other embodiments of the present invention, if the battery is in a state capable of supplying power when the mains power is out, it is used as an emergency power source for supply; if it is in a state without the ability to supply power, it is switched to a distributed power source.

[0026] The timing module M5 is connected to the first intelligent switching module M1. The timing module M5 is configured to count based on a set time when receiving the mains power outage instruction, and send a secondary switching instruction when the counted time meets the first preset time threshold. It can be understood that in the embodiment of the present invention, when the mains power is out, the counting module M5 is immediately triggered to start timing, and the set counting time is calculated based on the capacity consumption time of the battery. According to the set counting time, the power supply can be switched in time when the battery power supply is insufficient to ensure the stability of power supply. That is, regardless of the power supply state of the battery itself, the timing module M5 needs to be used for counting to fully ensure that the load can operate continuously and safely.

[0027] Correspondingly, the second intelligent switching module M2 is connected to the multi-distributed power module M4 and the battery module M3. The second intelligent switching module M2 is configured to switch the battery module M3 to the multi-distributed power module M4 to supply power to the load when receiving the secondary switching instruction. The multi-distributed power module M4 includes multiple distributed power sources of different types. The switching system supports dynamically increasing or decreasing the number of distributed power sources. When any one of the distributed power sources fails, it automatically switches between multiple distributed power sources. It should be noted that when the power supply time of the multi-distributed power module M4 meets the second preset time threshold, it will switch back to the battery module M3 for power supply. In this embodiment, the second preset time threshold is determined according to the time used for the power supply capacity of the multi-distributed power module to be consumed.

[0028] It can be seen that the embodiment of the present invention can comprehensively maintain the stability of the power system operation by setting two groups of switching mechanisms to cope with various emergencies. Among them, the first group of switching mechanisms is the process of switching to the battery when the mains power is out. The second group of switching mechanisms is the process of switching to the multi-distributed power source when the battery capacity is about to be exhausted.

[0029] Specifically, the first intelligent switching module M1 includes: a first control unit M11 and a first switching unit M12 controlled by the first control unit M11. The second intelligent switching module M2 includes: a second control unit M21 and a second switching unit M22 controlled by the second control unit M21.

[0030] Next, this embodiment will refine the operating principles of the above two sets of switching mechanisms in combination with the circuit structures corresponding to each module. Specifically, please refer to Figure 2 the content shown, Figure 2 which shows a schematic diagram of a multi-distributed power switching circuit structure in one embodiment of the present invention.

[0031] As Figure 2 shown on the left, the first switching unit M12 controlled by the first control unit M11 is composed of switch relays 11 and 12 connected to each other, and is connected to the mains input module M6 through the first control unit M11. Correspondingly, as Figure 2 shown on the right, the second switching unit M22 controlled by the second control unit M21 is composed of switch relays 21 and 22 connected to each other, and is connected to the battery and the multi-distributed power source through the second control unit M21.

[0032] In this embodiment, the first control unit M11 is connected between the switch relays 21 and 22 via the output terminal 2c of the second switching unit M21. When the corresponding switch relays are closed, the required connection loop is formed to achieve power switching. One output terminal of the timing module M5 is connected between the mains and the connection path of the first control unit M11, and the other output terminal is connected to the output terminal 1c of the first switching unit M12, and this output terminal 1c is connected to the load. Thus, the power supply of the timing module is supplied by the circuit connected between the load and the first intelligent switching module, so as to ensure that the timing module M5 can still work continuously when the mains power fails.

[0033] Regarding the first set of switching mechanisms, when the mains power fails, the first control unit M11 controls the switch relay 11 in the first switching unit M12 to disconnect and the switch relay 22 to close, and correspondingly, the second control unit M21 controls the switch relay 21 in the second switching unit M22 to close, so that the power supply is switched to the battery module M3. Among them, for the circuit structure of the first control unit M11, please refer to Figure 3 the figure shown. It can be seen that the first control unit M11 includes two sets of relays, relay X1 and relay X2, and the corresponding contacts aX1 and bX2 of relay X1, and the corresponding contacts aX2 and bX1 of relay X2.

[0034] It should be noted that, in order to physically isolate different power paths and prevent short circuits, the embodiments of the present invention design a relay interlock design, that is, by connecting the contacts of the relays in series / parallel (such as the reverse linkage of contact aX1 and contact bX2). That is, as Figure 3 shown, contact aX1 of relay X1 and contact bX2 of relay X2 are configured on circuit Q2. Then, by closing aX1 and bX2, circuit Q2 is closed, and at this time, the first intelligent switching module M1 is connected to the commercial power. Similarly, by closing aX2 and bX1, circuit Q3 is closed, so that the first intelligent switching module M1 is connected to other power sources (batteries and multiple distributed power sources). It should be noted that configuring contacts aX1, bX2, bX1, and aX2 opened and closed by relay X1 and relay X2 in the first intelligent switching module M1 can prevent short circuit accidents between the commercial power and other power sources.

[0035] From Figure 3 it can be seen that the timing module M5 is composed of a timing relay T1. Then, regarding the second group of switching mechanisms, in the state where the battery module M3 is connected to the first switching unit M1, after the timing relay T1 is turned on for a certain time (the time threshold set according to the battery capacity), the second control unit M21 controls the switch relay 21 in the second switching unit M22 to disconnect, while the switch relay 22 closes, so that the power supply is switched to the multi-distributed power module M4. The circuit structure of the second control unit M21 can be referred to Figure 4 shown. It can be seen that the second control unit M21 includes relay X3 and relay X4, contacts aX3 and bX4 corresponding to relay X3, contacts aX4 and bX3 corresponding to relay X4, and contacts aT1 and bT1 where relay X3 and X4 are connected in parallel with the timing relay T1.

[0036] Similar to the circuit structure of the first control unit M11, through relay interlock, contact aX3 of relay X3 and contact bX4 of relay X4 are connected in series on circuit Q4. Then, by closing aX3 and bX4, circuit Q4 is closed, so that the second intelligent switching module M2 is connected to the battery, and by closing aX4 and bX3, circuit Q5 is closed, so that the second intelligent switching module M2 is connected to the distributed power source. In addition, if the output of the distributed power module M4 stops, due to the disconnection of relay X4, the circuit connected in series with contact aX3 and bX4 of relay X3 is closed. At this time, the second intelligent switching module M2 will switch to the battery module M3 again to supply the power of the battery to the load. It should be noted that configuring contacts aX3, bX4, bX3, aX4 opened and closed by relay X3 and relay X4, and contacts aT1, bT1 corresponding to the opening and closing of the timing relay T1 in the second intelligent switching module M2 can prevent short circuit accidents between the commercial power and other power sources.

[0037] Specifically, for the results of operating according to the above two sets of mechanisms, please refer to the following table, which is the action table of the control circuit corresponding to the above control mechanism composed of relays, showing the relationship of the power supply states.

[0038] It can be seen that when the mains power is in the energized E1 state, at this time, if the battery or distributed power source is in the working state, not limited to the mains power, the battery or distributed power source can also supply electrical energy to the load. However, in order to maintain the previous state of relays X1 to X4, as long as the mains power is energized, even if the battery or distributed power source starts in the middle, the first intelligent switching module and the second intelligent switching module will not switch. Therefore, there will be no switching from the mains power to other power sources (battery and distributed power source).

[0039] After that, in the E2 state just after the mains power outage, if the battery is in a state where it can supply power, regardless of the state of the distributed power source, the power of the battery is supplied to the load.

[0040] However, in the case where the battery does not have the ability to supply power, it is switched to the distributed power source. Furthermore, in the state after the mains power has been out for a certain number of minutes, through the action of the timing relay T1, the power supply of the load is switched to the distributed power source. That is, regardless of the state of the battery, after the battery is enabled for a pre-set time (e.g., 30 minutes), the distributed power source is changed to supply power to the load.

[0041] However, in the case where the distributed power source does not have the supply ability, the power supply of the load will be switched back to be supplied with power from the battery 8. In this way, after the mains power outage (within the predetermined time), the battery power is supplied to the load connected to the circuit Q1. When the timer started due to the power outage counts beyond the predetermined time, the power supply is switched from the battery to the distributed power source. Therefore, when the mains power outage continues, the battery can also be switched to other power sources before the capacity is exhausted, ensuring that the battery can be used as an emergency power source and enabling the distributed power source to be used in a stable state. In addition, since the relays X1 to X4 in the first intelligent switching module and the second intelligent switching module constituted by the embodiments of the present invention are respectively driven by one kind of power supply, the switching control can be implemented without setting a complex power supply circuit, thereby reducing the cost of power supply switching.

[0042] The responses of multiple distributed power sources to the loss of mains power generally adopt an active operation mode. However, in this case, one of the distributed power sources needs to be set as the host and operate first to replace the missing mains power parameters. Then, the subordinate distributed power sources take the host power source as a reference and adjust their power parameters to be in phase with the host power parameters before grid connection. Based on this, in the embodiments of the present invention, a master-slave cooperation module is provided, which is used to designate one of the distributed power sources as the host and the rest as slaves when multiple distributed power sources are operating. During operation, the slaves need to shield their autonomous operation functions and synchronize the parameters of the host before grid-connected power supply. It can be understood that the slaves adjust the output voltage, frequency, and phase through a power regulator and close the grid connection switch after the parameters are consistent with those of the host. Preferably, the grid connection switch is a relay or a static switch, which is configured on the connection path between the slave and the host grid.

[0043] In some embodiments of the present invention, the master-slave cooperation module designates the host through any one of the following methods: an energy management system, hardware / software preset, or the slave's real-time detection of grid characteristic fluctuations. Specifically, the present invention will provide the following examples to elaborate on the above three implementation methods: Example 1: Designate the host through an energy management system (EMS), send a command to the slave to shield its autonomous operation function, and the slave synchronizes the voltage and frequency parameters output by the host before grid connection. Specifically, please refer to Figure 5 As shown, it can be seen that the system in this example includes multiple distributed power sources and a control device.

[0044] In this Example 1, three distributed power sources a, b, and c are selected, and each is configured to be composed of a control device, a power regulator, and an autonomous operation device. The control device consists of an EMS (energy management system). The control device is connected to the distributed power sources in a manner that enables communication, outputs and sends various control-related instructions to the distributed power sources. Each control device in the three distributed power sources is communicatively connected to the control device to receive the instructions output by the control device and control the corresponding distributed power source according to the received instructions. The power regulator set in this Example 1 can convert the power supplied and output by the distributed power source from direct current to alternating current that can be supplied to the load. In this Example 1, the autonomous operation device is used to prevent multiple distributed power sources from operating independently when detecting the interruption of power supply from the mains, which may cause non-synchronous grid connection.

[0045] Exemplarily, the communication methods between the distributed power source and the control device in this example include, but are not limited to: contact signals, analog signals, Ethernet, or serial signals.

[0046] Based on the above structure, when the system switches the storage battery to a distributed power source, for example, when the distributed power source a is set as the host, the distributed power sources b and c become slave units. In this case, the distributed power sources b and c will respectively shield the functions of the corresponding autonomous operation devices and use the distributed power source a set as the host as the power supply. It should be noted that in this example, the control device determines which of the distributed power sources a, b, and c should become the host. Specifically, the control device sends a main operation instruction to the distributed power source that becomes the host. During this process, a main operation instruction can be sent to any one of the distributed power sources, and a slave operation instruction is sent to the distributed power sources that become slave units. The distributed power source that receives the main operation instruction will start independent operation as the host, and the remaining distributed power sources that receive the slave operation instruction will shield their respective individual operation functions through the autonomous operation device, connect to the system, and operate.

[0047] Taking the case of sending a main operation instruction to the distributed power source a as an example, the connection and operation process of the distributed power sources in this Example 1 will be described below. Specifically, please refer to Figure 6 as shown, which includes the following steps: 1. Relay contact point monitoring: After the timing relay T1 is turned on for a certain period of time, that is, when the switch relay 21 is turned off and 22 is turned on, the control device sends a main operation instruction to the distributed power source a.

[0048] 2. The distributed power source a that receives this main operation instruction starts independent operation. For example, when the distributed power source a is a fuel cell, it starts autonomous independent operation by starting the fuel cell.

[0049] 3. The control device sends a slave operation instruction to the distributed power sources b and c that did not receive the main operation instruction in step 2. The distributed power sources b and c that receive the slave operation instruction respectively shield their autonomous operation devices and connect using the output electric energy of the distributed power source a as the commercial power. Among them, the slave operation instructions output by the control device can be sent to the distributed power sources b and c simultaneously or sequentially.

[0050] Example 2: The host is preset through hardware or software. After the host operates independently, it sends instructions to the slave units, and the slave units are connected to the grid according to the instructions. Specifically, please refer to Figure 7 as shown. Compared with Example 1, the system in this example does not include a control device, and the control devices in multiple distributed power sources are respectively connected in a state where they can communicate with each other.

[0051] In this Example 2, when the mains power fails and switches to battery power supply, and after the battery powers for a predetermined time and the electrical energy is converted into distributed power sources, the setting for a certain distributed power source to become the host is made in advance. Exemplarily, various methods can be considered for this setting method, such as setting the software and hardware structure of contact signals, switches or parameters. Any one of the distributed power sources a, b, and c can still be set as the host.

[0052] Since the distributed power source module of the present invention can dynamically increase the number of distributed power sources, even when a part of the already set distributed power sources are replaced, a part of the distributed power sources are removed, or new distributed power sources are added, hardware settings or software settings can be made. Subsequent operations such as instruction sending are the same as in Example 1 and will not be elaborated here.

[0053] Taking the case of outputting a main operation instruction to the distributed power source a as an example, the distributed power source connection operation process of this Example 2 will be described below. Specifically, please refer to Figure 8 as shown, which includes the following steps: 1. Relay contact point monitoring. After the timing relay T1 is turned on for a certain time, that is, when the switch relay 21 is turned off and 22 is turned on, the control device outputs an autonomous operation instruction to the distributed power source a.

[0054] 2. The control device outputs a slave operation instruction to the distributed power sources b and c. After receiving the slave operation instruction, actually the implementation steps of this Example 2 are similar to those of Example 1 and will not be elaborated here. The slave operation instructions output by the control device can be output by multiple control devices simultaneously or sequentially.

[0055] Example 3: The slave machine determines that the host has been put into operation by detecting the frequency stability or voltage fluctuation of the power grid, automatically shields the autonomous operation function and accesses the host system. Specifically, please refer to Figure 9 as shown, the system of this Example 3 is the same as that of Example 2. The difference is that in this Example 3, the control devices of multiple distributed power sources do not need to be able to communicate with each other separately. Therefore, each of the multiple distributed power sources does not need to receive a main operation instruction or a slave operation instruction from the regulation device or other distributed power sources.

[0056] In this Example 3, when the mains power fails and switches to battery power supply, and after the battery powers for a predetermined time and the electrical energy is converted into distributed power sources, the setting for a certain distributed power source to become the host or the slave is made in advance. The setting of the host and the slave is the same as that in Example 2 and Example 1, that is, any one can be the host or the slave. However, in this Example 3, only one of the multiple distributed power sources possessed by the system is set as the host. That is, instead of setting each distributed power source to become a slave, when setting multiple distributed power sources, the setting for one of them to become the host distributed power source can also be made.

[0057] When the system switches to multiple distributed power modules, the host starts independent operation according to its own judgment. Then, the slave machine detects that the host has started independent operation and, based on its own judgment, shields the function of the independent operation device of this machine and starts to operate by connecting to the power supply system established by the host. That is, when at least one of the changes in the mains frequency and voltage changes is less than a specified threshold, it is set that the distributed power in the slave machine determines that the host in the distributed power has started operation, and starts its own operation as a slave machine.

[0058] The independent operation device or the power regulator is designed to be able to detect the changes in the frequency and voltage of the collected voltage data.

[0059] It can be understood that when the distributed power as the host operates independently, the output of the host is a sine wave voltage of the reference frequency and the reference voltage. During this process, the power supplied from the mains generates frequency changes or voltage changes due to fluctuations in the rotational speed of the generator turbine, etc. The distributed power set as the slave machine can determine whether the system power supply is the original mains power or the power supplied by the distributed power that has just become the host and operates independently by monitoring the voltage data of the power supplied from the mains. Specifically, for the above-mentioned distributed power connection operation processing steps in this Example 3, please refer to Figure 10 as shown.

[0060] Furthermore, please refer to Figure 11 as shown. In another embodiment of this Example 3, the distributed power connection operation processing is a process executed by the control device of the distributed power preset as the slave machine. Taking the case where distributed power b is preset as the slave machine and distributed power a is preset as the host as an example, the supplementary description includes the following steps: 1. After the timing relay T1 is turned on for a certain time and the switch relay 21 is turned off and the switch relay 22 is turned on, the control device in the distributed power b as the slave machine starts to determine whether it is based on the independent operation of the host.

[0061] 2. When it is determined that the supplied power is not the host power, the distributed power connection operation processing in the slave machine ends. This can be understood as a scenario: for example, the mains switches to the battery and operates for a predetermined time, then switches to the distributed power, but immediately the mains power supply resumes.

[0062] 3. When it is determined that the supplied power is the host power, the control device, on the basis of shielding the function of the independent operation device of the distributed power b, connects and operates the distributed power b to the system with a as the host and the mains. In this way, after making the distributed power b start to operate as a slave machine, Figure 11The operation process of connecting the distributed power supply as shown is completed.

[0063] In summary, the system of the embodiment of the present invention is designed to include a mains input module, a first intelligent switching module, a second intelligent switching module, a timing module, a battery module, and a power switching system composed of a multi-distributed power module composed of a plurality of power supplies. The structure is simple and easy to operate, reducing the cost of power switching; through two sets of switching mechanisms, that is, controlling the switching between the mains and the battery through the first intelligent switching module, and controlling the switching between the battery and the distributed power supply through the second intelligent switching module. During this process, the timing module is used to set the consumption time of the power capacity, which can realize the smooth switching between the battery and the distributed power supply, and provide a master-slave machine cooperation module to coordinate the grid-connected operation of multiple distributed power supplies when the distributed power supply is powered, ensuring the stability of the grid-connected operation.

[0064] An embodiment of the present invention provides a multi-distributed power switching method, which is applied to the above multi-distributed power switching system. Specifically, please refer to Figure 12 As shown, it includes the following steps: S1. Real-time monitor the mains status through a voltage sensor. When the mains power outage is detected, trigger the power switching process; S2. In response to the power switching process instruction, disconnect the mains and start the timing module for countdown, and close the first contact corresponding to the battery input path in the first intelligent switching module, so that the power supply of the load is switched from the mains to the battery module; S3. When the timing module reaches the preset time threshold, disconnect the first contact and close the second contact corresponding to the distributed power supply input path in the second switching unit, so that the power supply of the load is switched from the battery module to the distributed power supply module; S4. When it is detected that the power supply of the distributed power supply module is interrupted, re-close the first contact and switch back to the battery module for power supply.

[0065] The technical features and technical effects of the multi-distributed power switching method proposed in the embodiment of the present invention are the same as those of the multi-distributed power switching system proposed in the embodiment of the present invention, and will not be elaborated here.

[0066] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A multi-distributed power supply switching system, characterized in that, Including: A mains power input module, a first intelligent switching module, a second intelligent switching module, a timing module, a battery module, and a multi-distributed power module composed of a plurality of power sources; The mains power input module is connected to the first intelligent switching module, and the mains power input module is used to provide mains power; The first intelligent switching module is connected to the second intelligent switching module. The first intelligent switching module is used to disconnect the mains power and switch to the battery module to supply power to the load when receiving a mains power outage instruction; The timing module is connected to the first intelligent switching module. The timing module is used to count based on a set time when receiving the mains power outage instruction. When the counting time meets a first preset time threshold, a secondary switching instruction is sent; The second intelligent switching module is connected to the multi-distributed power module and the battery module. The second intelligent switching module is used to switch the battery module to the multi-distributed power module to supply power to the load when receiving the secondary switching instruction.

2. The multi-distributed power supply switching system according to claim 1, characterized in that, The first intelligent switching module includes: a first control unit and a first switching unit controlled by the first control unit, wherein, the first switching unit is connected to the mains power input module through the first control unit. When the mains power is out, the first control unit controls the disconnection / closure of the corresponding contacts in the first switching unit to switch the power supply to the battery module.

3. The multi-distributed power supply switching system according to claim 1, characterized in that, The second intelligent switching module includes: a second control unit and a second switching unit controlled by the second control unit; When the counting of the timing module reaches the first preset time threshold, the second control unit controls the disconnection / closure of the corresponding contacts in the second switching unit to switch the power supply from the battery module to the multi-distributed power module.

4. The multi-distributed power supply switching system according to claim 1, characterized in that, When the power supply time of the multi-distributed power module meets a second preset time threshold, the multi-distributed power module is switched back to the battery module for power supply.

5. The multi-distributed power supply switching system according to claim 1, characterized in that, The power supply of the timing module is supplied by the circuit connected between the load and the first intelligent switching module.

6. The multi-distributed power supply switching system according to claim 1, characterized in that, The multi-distributed power module includes multiple distributed power sources, supports dynamically increasing or decreasing the number of distributed power sources, and automatically switches when any one of the distributed power sources fails.

7. The multi-distributed power supply switching system according to claim 6, characterized in that, It further includes a master-slave cooperation module for designating one of the distributed power sources as the master and the remaining distributed power sources as slaves when multiple distributed power sources are operating.

8. The multi-distributed power supply switching system according to claim 7, characterized in that, When multiple distributed power sources are operating, the slaves shield their autonomous operation functions and synchronize the parameters of the master and then perform grid-connected power supply.

9. The multi-distributed power supply switching system according to claim 7, characterized in that, The master-slave cooperation module is configured to designate the master through an energy management system, hardware / software preset, or the slaves' real-time detection of grid characteristic fluctuations.

10. A multi-distributed power supply switching method, characterized in that, Applied to the multi-distributed power switching system according to any one of claims 1 to 9, including: Real-time monitoring of the mains power status through a voltage sensor, and triggering the power switching process when detecting a mains power outage; In response to the power supply switching process instruction, disconnect the mains power and start the timing module for countdown, close the first contact corresponding to the battery input path in the first intelligent switching module, and switch the power supply of the load from the mains power to the battery module; When the timing module reaches the preset time threshold, disconnect the first contact and close the second contact corresponding to the distributed power input path in the second switching unit, so that the power supply of the load is switched from the battery module to the distributed power module; When it is detected that the power supply of the distributed power module is interrupted, re-close the first contact and switch back to the battery module for power supply.

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