Disclosure of Invention
The invention aims to provide a bus-based energy coordination control system of an energy storage power station, which is used for solving the problem of output consistency of a plurality of PCS (process control systems) of a large new energy station under the condition of quick response.
The technical scheme adopted by the invention is as follows:
The invention provides a bus-based energy storage power station energy coordination control method, which comprises the following steps:
step 1, a control host receives an instruction of a quick response requirement or detects the quick response requirement;
step 2, based on the instruction or response requirement received in the step 1, the control host calculates the active power of each PCS target;
Step 3, the control host transmits the single PCS target active power calculated in the step 2 to the local coordination controller through the real-time Ethernet network;
And 4, each local coordination controller transmits the PCS target active power received in the step 3 to the corresponding PCS through a communication bus, clock synchronization is carried out among the local coordination controllers, and each local coordination controller provides a corresponding PCS clock synchronization signal.
Preferably, in step 2, the calculation formula of the active power of each PCS target is as follows:
Wherein Pi is the target active output of a single PCS, Ptotal is the active total power adjustment instruction, Pmaxi is the i-th PCS discharge/charge maximum active power, mui is the charge/discharge active power coefficient, thetai is the enabling factor, and n is the number of PCS.
Preferably, θi =0 when the station PCS or battery fails;
PCS and battery are normal, θi =0 when corresponding to battery SOC >80% during charging, θi =0 when corresponding to battery SOC <20% during discharging;
Other cases θi =1.
The second aspect of the invention provides an energy coordination control system of an energy storage power station based on bus type, which comprises the following components:
a control host, an in-situ coordination controller, a real-time Ethernet, a communication bus and a PCS;
The control host is respectively connected with the scheduling end, the primary frequency modulation end and the on-site coordination controller through the real-time Ethernet, and the on-site coordination controller is connected with the PCS through a communication bus.
Preferably, the control host and the local coordination controller are of a double-machine double-ring network structure.
Preferably, the communication bus comprises a CAN bus and/or an RS485 bus.
Preferably, the in-situ coordination controller comprises a synchronization pulse generator, a real-time power calculation unit and a real-time ethernet communication bus interface;
The synchronous pulse generator is connected with the PCS through a low-delay pulse signal and is used for providing synchronous control pulses;
The real-time power calculation unit is used for collecting the output voltage and current values of the PCS on site and calculating the real-time active and reactive power output of the PCS;
the real-time Ethernet communication bus interface is connected with the control host through the real-time Ethernet.
The third aspect of the present invention provides a bus-type communication method, based on the control system of the bus-based energy coordination control system of the energy storage power station, comprising:
Step1, taking T as a period, a control host transmits a real-time Ethernet communication message frame, wherein a data part of the real-time Ethernet communication message frame comprises a PCS control field and a PCS information field;
Step 2, after receiving the communication message frame sent in step 1, the local coordination controller corresponding to the first PCS decodes the control field information belonging to the PCS in the control field, simultaneously writes the information of the PCS into the corresponding position of the information field of the communication message frame, and outputs the processed communication message frame;
Step 3, the communication message frame output in the step 2 is sent to the local coordination controller corresponding to the next PCS, the local coordination controller corresponding to the next PCS repeats the operation of the local coordination controller corresponding to the first PCS in the step 2 until the local coordination controller corresponding to the last PCS outputs the processed communication message frame, the communication message frame is returned to the control host, and the local coordination controllers corresponding to the PCS perform clock synchronization in the process of receiving and outputting the communication message frame;
and 4, the control host analyzes the communication message frame returned in the step 3 and acquires the state information of each PCS.
A fourth aspect of the present invention provides a terminal, including a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is operative according to the instructions to perform steps according to the method described above.
A fifth aspect of the present invention provides a computer-readable storage medium, having stored thereon a computer program,
Which when executed by a processor, implements the steps of the method described above.
The invention has the beneficial effects that:
(1) The bus-based energy storage power station energy coordination control system provided by the invention ensures the output synchronism of all PCS in quick response, and can realize minimum circulation under the condition that all PCS realize synchronous response, and the whole station can realize the functions of network construction control, black start and the like.
(2) The control host in the invention can form a plurality of independent communication networks through a plurality of real-time Ethernet communication bus interfaces and the local coordination controller, can meet the requirement that the PCS of the high-capacity energy storage station needs layering and branch line control, flexibly expands the control quantity of the PCS, and widens the application scene of the invention.
(3) The bus-based energy storage power station energy coordination control system provided by the invention does not need to read the active/reactive power of each PCS through communication with the PCS, but directly calculates the real-time power output of the PCS by the on-site coordination controller. Therefore, after the control host sends out the PCS output instruction from top to bottom, the PCS can respond quickly, and the response speed of the whole system is greatly improved.
(4) The bus-based energy coordination control system of the energy storage power station provided by the invention has the advantages that the local coordination controller and the control host communicate and transmit control instructions and state information through the real-time Ethernet bus. All PCS state information and control instructions on the bus can be completed by only one Ethernet communication message frame, and an in-situ coordination controller and a control host corresponding to each PCS are not required to independently transmit and receive messages, so that the number of communication messages in a network is greatly reduced, and the communication efficiency and the quick response speed of the whole system are improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. The described embodiments of the application are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art without inventive faculty, are within the scope of the application, based on the spirit of the application.
The existing energy coordination control system of the energy storage power station is mainly applied to scenes such as primary frequency modulation and inertia of quick response, but has a certain limit when the access quantity of PCS is determined by the CPU performance of the control system, and the existing system can not meet the requirements when the access quantity of PCS exceeds a certain quantity. For a large-scale energy storage power station, the coordination control of PCS has become an essential ring, so the embodiment of the invention provides the following technical scheme:
the embodiment of the invention provides a control method of an energy coordination control system of an energy storage power station based on a bus type, which comprises the following steps:
step 1, a control host receives an instruction of a quick response requirement or detects the quick response requirement;
As shown in fig. 3, when a new energy power station adopting chemical energy storage has a rapid response event, for example, a primary frequency modulation device detects the frequency change of a grid-connected point and needs to adjust the power output of the energy storage to achieve the purpose of frequency modulation, and the primary frequency modulation device issues a power value instruction to be adjusted to a control host.
Step 2, based on the instruction or response requirement received in the step 1, the control host calculates the active power of each PCS target;
the control host obtains the total Battery SOC of each container according to the received instruction value and PCS and BMS (Battery management system) information, and PCS maximum charging/discharging active power Pmaxi, so as to calculate the target active power of each PCS.
In a preferred but non-limiting embodiment of the present invention, the control host directly reads the information of the PCS and the BMS from the local coordination controller, the PCS itself does not need to calculate active/reactive power, and the local coordination controller obtains the real-time information of the PCS and calculates the active/reactive power, thereby improving the response speed of the whole control system.
However, in order to equalize the battery life of the total station, the control host needs to set an active power coefficient for each PCS to equalize the output of each PCS, where the active power coefficient is related to the SOH of the battery.
The PCS target active power calculation formula is as follows:
Wherein Pi is the active output of a single PCS target;
ptotal is an active total power adjustment instruction;
pmaxi is the i-th PCS discharge/charge maximum active power;
mui is the charging/discharging active power coefficient, and mui is 0-100% in value range;
θi is an enable factor;
n is the number of PCS. Wherein, when the PCS or the battery fails, θi =0, the PCS and the battery are normal, θi =0 when the corresponding battery SOC is more than 80% in the charging process, θi =0 when the corresponding battery SOC is less than 20% in the discharging process, and other cases θi =1.
The parameters can be adjusted according to specific conditions.
Step 3, the control host transmits the single PCS target active power calculated in the step 2 to the local coordination controller through the real-time Ethernet network;
Based on the single PCS target active power calculated by the control host and issued to each PCS, the single PCS target active power is issued to an in-situ coordination controller corresponding to each PCS through a real-time Ethernet network.
And 4, each local coordination controller transmits the PCS target active power received in the step 3 to the corresponding PCS through a communication bus mode, clock synchronization is carried out among the local coordination controllers, each local coordination controller provides a corresponding PCS clock synchronization signal, all PCS outputs are ensured to be simultaneously output, and the synchronization stability of power supply output is ensured.
In a preferred but non-limiting embodiment of the invention, the communication bus comprises a CAN bus and/or an RS485 bus.
According to the characteristics of the real-time Ethernet and the setting of clock synchronization signals, the real-time Ethernet system can ensure that the time difference of the synchronization signals sent to the PCS by each local coordination controller is in the nanosecond level, the time difference of the command value sent to the corresponding PCS by the first local coordination controller in the whole network and the time difference of the command value sent to the corresponding PCS by the last local coordination controller in the whole network are in the microsecond level, and thus the output synchronization of the PCS of the whole new energy station in the quick response occasion is ensured.
Meanwhile, the whole network adopts a clock synchronization technology, and layering and branching control can be flexibly performed when the quantity of the control PCS is large. Control consistency is not affected by network size and layering.
The bus-based energy storage power station energy coordination control system provided by the invention does not need to read the active/reactive power of each PCS through communication with the PCS, but directly calculates the real-time power output of the PCS by the on-site coordination controller. Therefore, after the control host sends out the PCS output instruction from top to bottom, the PCS can respond quickly, and the response speed of the whole system is greatly improved.
As shown in fig. 1, the embodiment of the invention further provides an energy coordination control system of the energy storage power station based on bus type, which comprises a control host, an in-situ coordination controller, a real-time ethernet, a communication bus and a PCS. The control host is connected with the AGC/AVC port and the primary frequency modulation port of the scheduling end through a real-time Ethernet, connected with the local coordination controller through the real-time Ethernet, and connected with the PCS through a communication bus. The control host and the local coordination controller both adopt double-machine double-ring network redundancy setting, thereby realizing equipment redundancy and communication redundancy.
The real-time Ethernet can ensure that each local coordination controller and a control host keep clock synchronization through a high-precision network time synchronization technology, ensure that the synchronous pulse difference sent to the PCS is at a nanosecond level, and simultaneously ensure that the time difference between an instruction output by a first local coordination controller to the PCS and an instruction output by a last local coordination controller to the PCS at the same time is at a microsecond level, thereby ensuring the consistency of the output of the PCS of the whole new energy station in a fast response occasion.
As shown in fig. 2, the in-situ coordination controller provided by the embodiment of the invention comprises a synchronous pulse generator, a real-time power calculation unit and a real-time ethernet communication bus interface. The synchronous pulse generator is connected with the PCS through a low-delay pulse signal and used for providing synchronous control pulses, the real-time power calculation unit is used for locally collecting output voltage and current values of the PCS and calculating real-time active and reactive output of the PCS by taking 20ms as a period when the system is 50Hz, and the real-time Ethernet communication bus interface is connected with the control host through a real-time Ethernet.
The local coordination controller ensures that all local coordination controllers connected with the host computer in each control command period receive the control command and transmit the control command to the PCS through the control host computer preset proper time, and then sends out synchronous control pulses through the synchronous pulse generator.
The PCS receives and analyzes the control instruction of the local coordination controller connected with the PCS, and finally, the adjustment of the power module is triggered through the synchronous pulse, so that all PCS can be output simultaneously.
In a preferred but non-limiting embodiment of the invention, the in-situ coordination controller is connected to the PCS via a communication bus, including a CAN bus and/or an RS485 bus.
The in-situ coordination controller is connected with the in-situ coordination controller of the next PCS bin through two paths of real-time Ethernet, and the in-situ coordination controller and the control host form a real-time Ethernet system of the whole energy storage power station.
The control host acquires PCS real-time power output and BMS information from the on-site coordination controller through a real-time Ethernet, wherein the acquired information comprises PCS active power, PCS reactive power, PCS state, PCS real-time maximum amplified active power, PCS real-time maximum chargeable active power, PCS real-time maximum expandable reactive power, SOC state of the battery and SOH state of the battery.
Wherein the PCS state includes shutdown, operation, failure.
The embodiment of the invention can realize PCS power synchronous output regardless of network level and scale by adopting synchronous clock and double-ring network communication redundancy. And secondly, the output of each PCS is calculated in real time by adopting an on-site coordination controller, the on-site PCS power feedback value is not depended, the rapid control of each PCS is achieved, and the rapid response speed of the whole system is improved.
In the embodiment of the invention, the local coordination controller adopts the CAN bus isolation chip, and the remote communication real-time Ethernet adopts the optical fiber medium, so that the anti-interference capability and the system stability of the system are improved.
As shown in fig. 4, the embodiment of the invention further provides a bus type communication method, which aims to reduce the sending of communication messages for PCS state information in a large-scale energy storage control station.
And step 1, taking T as a period, a control host transmits a real-time Ethernet communication message frame, wherein the real-time Ethernet communication message frame data part comprises a control field and an information field, the control field of each PCS comprises control enabling, active power and reactive power, and the information feedback field of each PCS comprises PCS active power, PCS reactive power, a PCS state, PCS real-time maximum amplified active power, PCS real-time maximum chargeable active power, PCS real-time maximum expandable reactive power, a SOC state of a battery and an SOH state of the battery.
Wherein PCS states include shutdown, operation, and failure.
And 2, after receiving the communication message frame sent in the step 1, the local coordination controller corresponding to the first PCS decodes the control field information belonging to the PCS in the control field, writes the information of the PCS into the corresponding position of the information field of the communication message frame, and outputs the processed communication message frame.
And 3, transmitting the communication message frame output in the step 2 to the local coordination controller corresponding to the next PCS, and repeating the operation of the local coordination controller corresponding to the first PCS in the step 2by the local coordination controller corresponding to the next PCS until the local coordination controller corresponding to the last PCS outputs the processed communication message frame, and returning the communication message frame to the control host, wherein the local coordination controllers corresponding to the PCS perform clock synchronization in the process of receiving and outputting the communication message frame. The control host sends out instructions for controlling all PCS by sending a communication message frame once, and receives information of all PCS, so that communication efficiency is improved.
And 4, the control host analyzes the communication message frame returned in the step 3 and acquires the state information of each PCS.
In a preferred but non-limiting embodiment of the present invention, the above procedure requires only one real-time ethernet frame to complete 50 PCS control and PCS status information reception. The processing of the communication message by the local coordination controller corresponding to each PCS can be completed in an FPGA (Field Programmable GATE ARRAY ), and the time for processing one communication node is less than 1us.
The present disclosure may be a system, method, and/or computer program product. The computer program product may include a computer readable storage medium having computer readable program instructions embodied thereon for causing a processor to implement aspects of the present disclosure.
The computer readable storage medium may be a tangible device that can hold and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical encoding device, punch cards or intra-groove protrusion structures such as those having instructions stored thereon, and any suitable combination of the foregoing. Computer-readable storage media, as used herein, are not to be construed as transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., optical pulses through fiber optic cables), or electrical signals transmitted through wires.
The computer readable program instructions described herein may be downloaded from a computer readable storage medium to a respective computing/processing device or to an external computer or external storage device over a network, such as the internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers and/or edge servers. The network interface card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium in the respective computing/processing device.
The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction Set Architecture (ISA) instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source or object code written in any combination of one or more programming languages, including an object oriented programming language such as SMALLTALK, C ++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (for example, through the Internet using an Internet service provider). In some embodiments, aspects of the present disclosure are implemented by personalizing electronic circuitry, such as programmable logic circuitry, field Programmable Gate Arrays (FPGAs), or Programmable Logic Arrays (PLAs), with state information of computer readable program instructions, which can execute the computer readable program instructions.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention, and any modifications and equivalents are intended to be included in the scope of the claims of the present invention.