Multi-machine synchronous control method of energy storage converter and energy storage system

Abstract

In order to overcome the defects in the prior art, the invention provides an energy storage converter multi-machine synchronous control method and an energy storage system, and the method comprises a main control layer, a sub-control layer and an energy storage converter module. The master control layer receives and collects grid-connected point control information of the whole energy storage system to carry out phase locking calculation, and then sends a phase locking result and control power to the sub-control layer. And the sub-control layer analyzes the received phase locking result, controls power, synchronizes clock information according to the phase locking result, and performs power control on the corresponding energy storage converter module according to the control power information. When parallel operation of multiple energy storage converters is realized, all the converters are subjected to algorithm-level unified control, and numerous problems caused by asynchronous clocks and asynchronous responses during parallel operation of multiple energy storage converters are solved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a multi-machine synchronous control method of an energy storage converter and an energy storage system. Background Art

[0002] The power storage converter (PCS) can control the charging and discharging process of the battery, perform AC / DC conversion, and directly supply power to the AC load when there is no power grid. The PCS consists of a DC / AC bidirectional converter, a control unit, etc. The PCS controller receives background control instructions through communication, and controls the converter to charge or discharge the battery according to the sign and size of the power instruction, thereby adjusting the active power and reactive power of the power grid.

[0003] For energy storage systems with multiple energy storage inverters, due to the limitations of chip resources and communication speed, the existing technology adopts a method of independent control, which can easily cause clock asynchrony and response asynchrony, thereby causing many problems such as control lag and grid oscillation. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, one of the objectives of the present invention is to provide a method for synchronously controlling multiple machines of an energy storage converter, comprising: a main control layer, a sub-control layer, and an energy storage converter module.

[0005] After receiving and collecting the grid connection point control information of the entire energy storage system and performing phase-locking calculation, the main control layer sends the phase-locking result and control power to the sub-control layer.

[0006] The sub-control layer analyzes the received phase-locking result and controls the power, synchronizes the clock information according to the phase-locking result, and performs power control on the corresponding energy storage converter module according to the control power information.

[0007] Optionally, the sub-control layer is a layer including a plurality of sub-control terminals. The sub-control terminals parse the main control information sent by the main control layer to form energy storage converter module control information for the corresponding energy storage converter module.

[0008] The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

[0009] Optionally, the sub-control layer includes at least two layers, each sub-control layer includes several sub-control terminals, the sub-control layer connected to the main control layer signal is the highest level sub-control layer, and the sub-control layer connected to the energy storage converter module signal is the lowest level sub-control layer. At least one of the sub-control terminals in the high-level sub-control layer is connected to at least two of the sub-control terminals in the low-level sub-control layer, and the sub-control terminals at each level only receive one upper-level signal source information.

[0010] After receiving and parsing the main control information sent by the main control layer, the high-level sub-control layer forms the N-1th layer sub-control control information for the secondary sub-control layer or the energy storage converter module control information for the corresponding energy storage converter module, where N is the total number of sub-control layers.

[0011] After parsing the control information sent by the upper sub-control layer, the sub-control terminals at each level form the Mth sub-control control information for the lower sub-control layer or the energy storage converter module control information for the corresponding energy storage converter module, where M is the number of levels and M<N.

[0012] The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

[0013] Furthermore, the control information sent by the main control layer includes: a control signal package for each target energy storage converter module, and the control signal package includes: target address brief information, security key information, and encrypted energy storage converter module control information.

[0014] The target address brief information includes: hierarchical address and affiliation information between the sub-control layer connected to the main control layer signal and the sub-control layer connected to the energy storage converter module number.

[0015] The security key information is an encryption key synchronized between the master controller and the sub-controller.

[0016] The encrypted energy storage converter module control information is the energy storage converter module number and energy storage converter module control information encrypted based on the security key.

[0017] Furthermore, the sub-control terminal first obtains the target address brief information of each control signal packet during parsing, and intercepts the control signal packet related to its own address for sub-packetization or security key information parsing.

[0018] Furthermore, the subcontract is:

[0019] First, the address of the sub-control terminal and the addresses of the lower-layer sub-control terminals directly or indirectly connected to the sub-control terminal are obtained from the target address brief information.

[0020] Then, the security key information is parsed for the address information of the lower-level sub-control terminals that are not directly or indirectly connected to the sub-control terminal. For the address information of the lower-level sub-control terminals that are directly or indirectly connected to the sub-control terminal, the address information of the sub-control terminal is deleted, and the control signal packet is sent to all sub-control terminals of the next level connected to the sub-control terminal.

[0021] Furthermore, the security key information parsing includes:

[0022] First, the security key information is obtained, and the integrity of the security key information is verified according to the internal verification rules.

[0023] Then, the verified security key information is decrypted according to the internal decryption rules to obtain the decryption rules of the encrypted energy storage converter module control information.

[0024] Then, based on the obtained decryption rule of the encrypted energy storage converter module control information, the encrypted energy storage converter module control information is decrypted to obtain the energy storage converter module number and the energy storage converter module control information.

[0025] Finally, the corresponding energy storage converter module control information is sent to the corresponding energy storage converter module according to the obtained energy storage converter module number.

[0026] In addition, the present invention also provides an energy storage system, including: a plurality of batteries, a plurality of energy storage inverters matched with the batteries for controlling the charging and discharging of the batteries, and a control system for controlling all energy storage inverters. The plurality of energy storage inverters are divided into at least two groups, and the control system includes a plurality of sub-control terminals and at least one main control layer module. Each of the main control layer modules is connected to control at least two sub-control terminals, and each group of energy storage inverters is connected to the corresponding main control layer module signal through at least one sub-control terminal. The control system executes the steps in the above-mentioned energy storage inverter multi-machine synchronous control method.

[0027] Furthermore, the main control layer and the sub-control terminal, the upper-level sub-control terminal and the lower-level sub-control terminal, and the sub-control terminal and the energy storage converter module are connected by high-speed communication signals, and the phase-locking results are sent through clock synchronization optical fiber.

[0028] The beneficial effects of the present invention are:

[0029] 1. When the present invention realizes parallel operation of multiple energy storage converters, all converters are uniformly controlled at the algorithm level, thereby solving many problems caused by clock asynchrony and response asynchrony when multiple energy storage converters are operated in parallel.

[0030] 2. The present invention has good information security capabilities, and specific energy storage converter control instructions are encrypted for transmission, thereby improving the security of energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a schematic diagram of the structure of a first-level distributed control energy storage system.

[0032] Figure 2 Shown is a schematic diagram of the structure of a multi-level controlled energy storage system. DETAILED DESCRIPTION

[0033] The present invention will now be described in further detail with reference to the accompanying drawings.

[0034] Example 1

[0035] A method for synchronously controlling multiple machines of an energy storage converter comprises: a main control layer, a sub-control layer, and an energy storage converter module.

[0036] After receiving and collecting the grid connection point control information of the entire energy storage system and performing phase-locking calculation, the main control layer sends the phase-locking result and control power to the sub-control layer.

[0037] The sub-control layer analyzes the received phase-locking result and controls the power, synchronizes the clock information according to the phase-locking result, and performs power control on the corresponding energy storage converter module according to the control power information.

[0038] Compared with the prior art that requires independent control of several energy storage inverters, the present invention uses a master control combined with a sub-control method to uniformly control all inverters at the algorithm level, so that the energy storage inverters that need to be synchronously controlled can be synchronously controlled through the same sub-control terminal, effectively solving many problems caused by clock asynchrony and response asynchrony when multiple energy storage inverters are running in parallel.

[0039] Example 2

[0040] Based on the energy storage converter multi-machine synchronous control method of embodiment 1, Figure 1 As shown, the sub-control layer is one layer, including two or three or four sub-control terminals or other design required numbers. The sub-control terminals parse the main control information sent by the main control layer to form energy storage converter module control information for the corresponding energy storage converter module.

[0041] The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

[0042] At this time, the main control layer receives the control information of each energy storage inverter module, classifies the control information according to the network address or physical address information of the energy storage inverter module, and centrally and synchronously sends the synchronization control information of the same group of energy storage inverter modules through the corresponding sub-control terminals, so that the energy storage inverter modules connected to the same sub-control terminal can perform corresponding actions synchronously.

[0043] Example 3

[0044] Based on the energy storage converter multi-machine synchronous control method of embodiment 1, Figure 2As shown, the sub-control layer includes two, three, or four layers or other layers required by the design, and each sub-control layer includes two, three, or four or other sub-control terminals required by the design. The sub-control layer connected to the main control layer signal is the highest level sub-control layer, and the sub-control layer connected to the energy storage converter module signal is the lowest level sub-control layer. At least one of the sub-control terminals in the high-level sub-control layer is connected to at least two of the sub-control terminals in the low-level sub-control layer, and each sub-control terminal at each level only receives information from one upper-level signal source.

[0045] After receiving and parsing the main control information sent by the main control layer, the high-level sub-control layer forms the N-1th layer sub-control control information for the secondary sub-control layer or the energy storage converter module control information for the corresponding energy storage converter module, where N is the total number of sub-control layers.

[0046] After parsing the control information sent by the upper sub-control layer, the sub-control terminals at each level form the Mth sub-control control information for the lower sub-control layer or the energy storage converter module control information for the corresponding energy storage converter module, where M is the number of levels and M<N.

[0047] The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

[0048] by Figure 2 For example, at this time, the sub-control terminal has one input port and six output ports. N is the total number of sub-control layers, that is: N = 3, where the high-level sub-control layer connected to the main control layer is the third layer, and this layer is composed of sub-control terminals. The second layer has sub-control terminals and energy storage converters, among which some of the sub-control terminals of the third layer are respectively connected to 2-6 sub-control terminals of this layer, and the remaining sub-control terminals of the third layer are connected to 1-6 energy storage converter modules of this layer. The first layer has sub-control terminals and energy storage converters, among which some of the sub-control terminals of the second layer are respectively connected to 2-6 sub-control terminals of this layer, and the remaining sub-control terminals of the second layer are connected to 1-6 energy storage converter modules of this layer. The sub-control terminals of the first layer are respectively connected to 1-6 energy storage converter modules.

[0049] At this time, the main control layer receives the control information of each energy storage converter module, and classifies the control information according to the high-level sub-control layer according to the network address or physical address information of the energy storage converter module, and sends it to the corresponding sub-control terminals of the high-level sub-control layer. The sub-control terminals of the high-level sub-control layer split the information according to the received control information and the network address or physical address information of the corresponding lower-level energy storage converter module, and send it to the corresponding energy storage converter module or each sub-control terminal of the sub-control layer, and so on until all energy storage converter modules receive the corresponding control information. By constructing sub-control layer structures with different structures, this method can, on the one hand, centrally and synchronously send the synchronous control information of the energy storage converter modules in the same group through the corresponding sub-control terminals, so that the energy storage converter modules connected to the same sub-control terminal can perform synchronous corresponding actions. On the other hand, according to the number of energy storage converter module groups that need to be controlled differently and the number of energy storage converter modules in the same group, a multi-level hierarchical network can be built based on the connection capacity of the sub-control terminal or the physical address of the energy storage converter module, so that the networking capacity can be more flexible.

[0050] Example 4

[0051] Based on the energy storage converter multi-machine synchronous control method of the above embodiment, the control information sent by the main control layer includes: a control signal package for each target energy storage converter module, and the control signal package includes: target address brief information, security key information, and encrypted energy storage converter module control information.

[0052] The target address brief information includes: hierarchical address and affiliation information between the sub-control layer connected to the main control layer signal and the sub-control layer connected to the energy storage converter module number.

[0053] The security key information is an encryption key synchronized between the master controller and the sub-controller.

[0054] The encrypted energy storage converter module control information is the energy storage converter module number and energy storage converter module control information encrypted based on the security key.

[0055] The sub-control terminal first obtains the target address brief information of each control signal packet, and intercepts the control signal packet related to its own address for sub-packetization or security key information analysis.

[0056] The subcontracts are:

[0057] First, the address of the sub-control terminal and the addresses of the lower-layer sub-control terminals directly or indirectly connected to the sub-control terminal are obtained from the target address brief information.

[0058] Then, the security key information is parsed for the address information of the lower-level sub-control terminals that are not directly or indirectly connected to the sub-control terminal. For the address information of the lower-level sub-control terminals that are directly or indirectly connected to the sub-control terminal, the address information of the sub-control terminal is deleted, and the control signal packet is sent to all sub-control terminals of the next level connected to the sub-control terminal.

[0059] The security key information parsing includes:

[0060] First, the security key information is obtained, and the integrity of the security key information is verified according to the internal verification rules.

[0061] Then, the verified security key information is decrypted according to the internal decryption rules to obtain the decryption rules of the encrypted energy storage converter module control information.

[0062] Then, based on the obtained decryption rule of the encrypted energy storage converter module control information, the encrypted energy storage converter module control information is decrypted to obtain the energy storage converter module number and the energy storage converter module control information.

[0063] Finally, the corresponding energy storage converter module control information is sent to the corresponding energy storage converter module according to the obtained energy storage converter module number.

[0064] For information security considerations, the present invention encrypts the energy storage inverter module control information. The encryption method can be garbled information formed by disrupting the information based on specific rules, or encrypted information with a password attached. However, when the sub-control terminal processes the information, it needs to clarify which energy storage inverter module each energy storage inverter module control information is sent to. At this time, the existing technology will go to the sub-control terminal to decode first, and then send the energy storage inverter module control information connected to itself to the corresponding energy storage inverter module after obtaining all the information, or re-encrypt and send it to the next level of sub-control terminal, and the energy storage inverter module control information not connected to itself is discarded. Since the sub-control terminal needs to decode all the information, on the one hand, it causes the insecurity of the information transmission process, and on the other hand, it causes an increase in the resources required for the sub-control terminal operation, and the sub-control terminal usually does not have a strong computing power, which can easily cause a delay in information transmission.

[0065] Therefore, the present invention improves the composition of information and the corresponding information identification and judgment method, so that the control signal package includes: target address brief information, security key information, and encrypted energy storage inverter module control information. In this way, when the sub-control terminal identifies the information, the first step is to identify the target address brief information without decrypting and identifying the entire information. When the identified target address brief information is related to itself, the decryption method or encryption password of the encrypted energy storage inverter module control information is obtained according to the security key information to decrypt the encrypted energy storage inverter module control information, or send the entire control signal package to the lower-level sub-control terminal of the corresponding address without decryption, identification, and encryption. In the present invention, the energy storage inverter module control information only needs to be decrypted at the directly connected sub-control terminal, and the information is kept confidential during the rest of the sending process, which saves computing resources and ensures the security of the information.

[0066] Example 5

[0067] An energy storage system includes: a plurality of batteries, a plurality of energy storage converters matched with the batteries for controlling the charging and discharging of the batteries, and a control system for controlling all energy storage converters. The plurality of energy storage converters are divided into at least two groups, and the control system includes a plurality of sub-control terminals and at least one main control layer module. Each of the main control layer modules is connected to control at least two sub-control terminals, and each group of energy storage converters is connected to the corresponding main control layer module signal through at least one sub-control terminal. The control system executes the steps in the energy storage converter multi-machine synchronous control method in the above embodiment.

[0068] The main control layer and the sub-control terminal, the upper-level sub-control terminal and the lower-level sub-control terminal, and the sub-control terminal and the energy storage converter module are connected by high-speed communication signals, and the phase-locking results are sent through clock synchronization optical fiber.

[0069] The energy storage system uses the energy storage converter multi-machine synchronous control method of the present invention to centrally and uniformly control the energy storage converter, which can effectively solve many problems caused by clock asynchrony and response asynchrony when multiple energy storage converters are operated in parallel.

[0070] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for synchronously controlling multiple machines of an energy storage converter, characterized in that: include: Main control layer, sub-control layer, energy storage converter module; The main control layer receives and collects the grid connection point control information of the entire energy storage system for phase-locking calculation, and sends the phase-locking result and control power to the sub-control layer; The sub-control layer analyzes the received phase-locking result and controls the power, synchronizes the clock information according to the phase-locking result, and performs power control on the corresponding energy storage converter module according to the control power information.

2. The method for synchronously controlling multiple energy storage converters according to claim 1, characterized in that: The sub-control layer is a layer, including several sub-control terminals; the sub-control terminals parse the main control information sent by the main control layer to form energy storage converter module control information for the corresponding energy storage converter module; The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

3. The method for synchronously controlling multiple energy storage converters according to claim 1, characterized in that: The sub-control layer includes at least two layers, each of which includes several sub-control terminals. The sub-control layer connected to the main control layer signal is the highest level sub-control layer, and the sub-control layer connected to the energy storage converter module signal is the lowest level sub-control layer; at least one of the sub-control terminals in the high-level sub-control layer is connected to at least two of the sub-control terminals in the low-level sub-control layer, and each level of sub-control terminals only receives one upper-level signal source information; After receiving and parsing the main control information sent by the main control layer, the high-level sub-control layer forms the sub-control information of the N-1th layer of the secondary sub-control layer or the energy storage converter module control information of the corresponding energy storage converter module, where N is the total number of sub-control layers; After parsing the control information sent by the upper sub-control layer, the sub-control terminal of each level forms the M-th sub-control control information for the lower sub-control layer or the energy storage converter module control information for the corresponding energy storage converter module, where M is the number of levels and M<N; The energy storage converter module performs corresponding actions after receiving corresponding energy storage converter module control information.

4. The method for synchronously controlling multiple energy storage converters according to any one of claims 2 or 3, characterized in that: The control information sent by the main control layer includes: a control signal packet for each target energy storage converter module, the control signal packet includes: target address brief information, security key information, and encrypted energy storage converter module control information; The target address brief information includes: hierarchical address and affiliation information between the sub-control layer connected to the main control layer signal and the sub-control layer connected to the energy storage converter module number; The security key information is an encryption key synchronized between the master control and the sub-controller; The encrypted energy storage converter module control information is the energy storage converter module number and energy storage converter module control information encrypted based on a security key.

5. The method for synchronously controlling multiple energy storage converters according to claim 4, characterized in that: The sub-control terminal first obtains the target address brief information of each control signal packet, and intercepts the control signal packet related to its own address for sub-packetization or security key information analysis.

6. The method for synchronously controlling multiple energy storage converters according to claim 5, characterized in that: The subcontracts are: First, the address of the sub-control terminal and the addresses of the lower-layer sub-control terminals directly or indirectly connected to the sub-control terminal are obtained from the target address brief information; Then, the security key information is parsed for the address information of the lower-level sub-control terminals that are not directly or indirectly connected to this sub-control terminal; for the address information of the lower-level sub-control terminals that are directly or indirectly connected to this sub-control terminal, the address information of this sub-control terminal is deleted, and the control signal packet is sent to all sub-control terminals of the next level connected to this sub-control terminal.

7. The method for synchronously controlling multiple energy storage converters according to any one of claims 5 or 6, characterized in that: The security key information parsing includes: First, the security key information is obtained, and the integrity of the security key information is verified according to the internal verification rules; Then, the verified security key information is decrypted according to the internal decryption rules to obtain the decryption rules of the encrypted energy storage converter module control information; Then, based on the obtained decryption rule of the encrypted energy storage converter module control information, the encrypted energy storage converter module control information is decrypted to obtain the energy storage converter module number and the energy storage converter module control information; Finally, the corresponding energy storage converter module control information is sent to the corresponding energy storage converter module according to the obtained energy storage converter module number.

8. An energy storage system comprising: Several batteries, several energy storage inverters matched with the batteries for controlling the charging and discharging of the batteries, and a control system for controlling all the energy storage inverters, characterized in that the several energy storage inverters are divided into at least two groups, and the control system includes several sub-control terminals and at least one main control layer module; each of the main control layer modules is connected to control at least two sub-control terminals, and each group of energy storage inverters is connected to the corresponding main control layer module signal through at least one sub-control terminal; the control system executes the steps in the multi-machine synchronous control method of the energy storage inverter described in any one of claims 1-7.

9. The method for synchronously controlling multiple energy storage converters according to claim 8, characterized in that: The main control layer and the sub-control terminal, the upper-level sub-control terminal and the lower-level sub-control terminal, and the sub-control terminal and the energy storage converter module are connected by high-speed communication signals, and the phase-locking results are sent through clock synchronization optical fiber.

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