CN-121984630-A - Master-slave synchronous communication method suitable for cascade high-voltage direct-hanging energy storage system

CN121984630ACN 121984630 ACN121984630 ACN 121984630ACN-121984630-A

Abstract

The invention relates to the field of high-voltage equipment communication, in particular to a master-slave synchronous communication method suitable for a cascading high-voltage direct-hanging energy storage system, which comprises the following steps that each channel of a master controller is provided with an independent transmission timer, each transmission timer of each channel is provided with an independent transmission period, and the transmission period is obtained by subtracting a communication delay calculated according to the last communication between the master and slave from a reference period; the master controller sends data to each slave controller, when the data of the last channel of the master controller is sent and the response signals of the corresponding slave controllers are received, the sending timers of all channels are restarted, when the sending timers reach the sending period, the master controller restarts the next sending of the data, each channel of the slave controller is provided with an independent sending timer, and a synchronous communication control mechanism from the slave controller to each power unit adopts a synchronous starting mechanism between the master controller and each slave controller. The invention can synchronously control the high precision of each level of power units.

Inventors

MAO YIFAN
GAO SHUAI
ZHONG ZHIWEN
GUO HAIYAN
WU SHENGBING
ZHOU YUNPENG

Assignees

广州智光电气技术有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. The master-slave synchronous communication method suitable for the cascade high-voltage direct-hanging energy storage system is based on a communication architecture of a master controller, a slave controller and a power unit and is characterized by comprising the following steps of: S1, each channel of the master controller is provided with an independent transmission timer, each transmission timer of each channel has an independent transmission period, the transmission period is obtained by subtracting communication delay from a reference period T, wherein the communication delay is obtained by calculation according to the last communication between the master controller and the corresponding slave controller; And S2, the communication architecture from the slave controller to each power unit is the same as that from the master controller to each slave controller, an independent transmission timer is arranged on each channel of the slave controller, and a synchronous communication control mechanism from the slave controller to each power unit adopts a synchronous starting mechanism between the master controller and each slave controller in the step S1.
2. The master-slave synchronous communication method according to claim 1, wherein in step S2, for the communication from the slave controller to each power unit, the transmission timer of each channel of the slave controller is restarted when the data transmission of the last channel of the slave controller is completed and the response signal of the corresponding power unit is received, and until the master controller transmits data to the slave controller.
3. The master-slave synchronous communication method according to claim 1, wherein in step S2, the transmission period of the transmission timer of each channel of the slave is obtained by subtracting the corresponding communication delay from the communication delay buffer period T' of the slave and the power unit, wherein the corresponding communication delay is calculated from the last communication between the slave and the corresponding power unit.
4. The master-slave synchronous communication method according to claim 1, wherein step S1 comprises: S11, when the transmission timer of each channel of the master controller is started, loading the same reference period T as an initial value, simultaneously starting to decrease, and after the transmission timer is zeroed, starting an independent communication delay timer of each channel and transmitting data to each slave controller; s12, each slave controller waits for data to be received, and immediately returns a response signal when the data is normally received; s13, each channel of the master controller waits for a response of the corresponding slave controller after sending data; s14, after the corresponding channel of the master controller receives the response signal of the slave controller, stopping the communication delay timer, and calculating to obtain the communication delay; S15, according to the obtained communication delay, counting down the transmission timer of the corresponding channel of the main controller in the next communication, setting the transmission completion flag of the corresponding channel to be 1, and restarting the transmission timers of all channels after the transmission completion flag of all channels of the main controller is set to be 1.
5. The method according to claim 4, wherein in step S12, each slave controller is provided with a reception timeout determination mechanism, and if the last reception timeout is reached, a communication failure is indicated.
6. The master-slave synchronous communication method according to claim 4, wherein in step S13, the master controller is provided with a response timeout fault judging mechanism, if the response signal is received timeout, the number of frame errors is accumulated first, and the transmission completion signal is put in place to wait for the next transmission, and when the number of frame errors is accumulated to a preset upper limit, the communication fault is reported.
7. The master-slave synchronous communication method according to claim 4, wherein in step S14, the transmission communication delay between the master controller and the slave controller is equal to the reception communication delay, and the value of the communication delay timer is twice the communication delay of the corresponding channel at the present time of communication.
8. The master-slave synchronous communication method according to claim 4, wherein in step S15, assuming that the communication delay of the kth communication of the channel x is d x (k), there is: T x (k+1) = T - d x (k); Wherein T x (k+1) counts down the transmit timer for the corresponding channel at the k+1th communication; after the count down T x (k+1) of the transmission timer is calculated, the transmission completion flag of the corresponding channel is set to 1.
9. A master-slave synchronous communication method according to claim 3, wherein for the communication between the master controller and each slave controller, T > d max +t ', where T is a reference period, d max is a communication maximum delay of the master controller and the slave controller, and T' is a communication delay buffer period of the slave controller and the power unit; For communication between the slave and each power cell, the slave to power cell communication delay buffer period T' is greater than the slave to power cell communication maximum delay.
10. A storage medium having stored thereon computer instructions, which when executed by a processor, implement the steps of the master-slave synchronous communication method of any of claims 1-9.

Description

Master-slave synchronous communication method suitable for cascade high-voltage direct-hanging energy storage system Technical Field The invention relates to the field of high-voltage equipment communication, in particular to a master-slave synchronous communication method suitable for a cascading high-voltage direct-hanging energy storage system. Background The cascading type high-voltage direct-hanging energy storage system has become a key technology for large-scale energy storage application due to the remarkable advantages of the cascading type high-voltage direct-hanging energy storage system in terms of topological structure, output voltage quality and modularization. In the cascade high-voltage direct-hanging energy storage system, communication synchronization between a main controller and each power unit is a core technology foundation for realizing unified and coordinated operation of the system. The main controller relies on real-time, accurate and periodic consistent communication to synchronously collect key parameters such as voltage, current, temperature and the like of each unit, and realize unified issuing of PWM pulse signals. Any communication dyssynchrony will cause a timing deviation when a pulse command propagates among hundreds of units, thereby causing an increase in internal circulation and distortion of output voltage, and even threatening the stability of a power grid when serious. Communication synchronization is also a prerequisite for implementing voltage-sharing and current-sharing control and realizing a safety protection function. Only under a strictly synchronous communication architecture, the main controller can accurately judge the state difference of each unit, realize dynamic voltage-sharing and current-limiting management, and timely locate and isolate fault units. If the communication is out of sync, the system will lose its ability to quickly protect, possibly causing overload or chain damage to the unit. In addition, advanced functions including battery state assessment, life prediction are also highly dependent on timing consistency of data acquisition and transmission in the communication system. In order to effectively manage a large number of power cells in an energy storage system, one way is to employ a layered master-slave control architecture of "master-slave-power cells". In this architecture, the master controller issues higher-level instructions, and each slave controller (one per bin) receives the instructions and forwards the instructions to its managed N power units. The stable operation of the system, in particular the realization of high quality electrical energy output (such as low THD) and power equalization between the modules, is highly dependent on the high precision synchronization of the switching actions of all power units. However, in the secondary forwarding process of the "master-slave", the communication signal inevitably introduces a delay, resulting in that the delay time for each power unit to receive the control instruction is finally inconsistent. This will directly lead to the switching sequences of the units being disordered, causing circulation, harmonic distortion and even over-voltage or over-current of the individual units, which seriously threatens the system safety. Thus, a suitable communication scheme is urgently needed, so that a truly synchronous control of all power units is achieved. Currently, for a hierarchical master-slave control architecture, there are the following communication schemes: (1) The system is provided with high-precision clock sources for all master and slave controllers, and establishes a global unified time reference. The master controller, upon issuing a control command, will timestamp the data packet with a "future" absolute time (e.g., current time T + fixed offset Δt). All slave controllers, upon receiving the instruction, do not forward it immediately, but rather buffer it until the moment the local global clock reaches the absolute timestamp specified by the packet, and do not issue instructions to the respective managed power units at the same time. (2) Based on a synchronous communication mechanism triggered by hardware, a special hardware synchronous signal line (such as differential signal) is additionally introduced in the scheme. After sending the data message, the main controller sends out a hardware synchronization pulse. The pulse signal is transferred to all slave controllers via a star or daisy-chained topology. And the slave controller issues the previously received and cached master controller instruction to the power unit at the moment of receiving the synchronization pulse, so that the synchronization of actions is realized. For the synchronous communication mechanism based on the global time stamp, although the mechanism can realize higher instruction synchronous precision, the disadvantage of the mechanism is not ignored. First, the system needs to configure a high-precision