CN-121984076-A - Energy storage system, energy storage device and control method of energy storage system

CN121984076ACN 121984076 ACN121984076 ACN 121984076ACN-121984076-A

Abstract

The application relates to an electric energy storage technology and discloses an energy storage system, an energy storage device and a control method of the energy storage system, wherein the energy storage system comprises a battery module, an energy storage converter, a power detection unit and an energy management system; the power management system is respectively communicated with the energy storage converter, the power detection unit, the battery management system and the power generation unit, and is configured to acquire real-time operation power of the power generation unit, execute a power distribution strategy based on the power data of the load fed back by the power detection unit, and control the energy storage converter to enter a charging state when the power data of the load is lower than the lower limit value of the preset power operation interval of the power generation unit so as to increase the output load of the power generation unit, so that the actual output power of the power generation unit is maintained in the preset power operation interval, and the system operation efficiency is improved.

Inventors

LIU HONGBIN
ZHAO QIANG
CAO RUI
DU JIANFENG

Assignees

首帆动力科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. An energy storage system for connecting in parallel with a power generation unit (50) to an ac bus to power a load (60), the energy storage system comprising: A battery module (10) including a battery management system (11) and a battery cluster (12); an energy storage converter (20), the direct current side of which is connected to the battery cluster (12), the alternating current side of which is connected to the alternating current bus and which is configured to operate in a virtual synchronous machine mode; The power detection unit (30) is arranged at the input end of the alternating current bus or the load (60) and is used for collecting power data of the load (60); An energy management system (40) in communication with the energy storage converter (20), the power detection unit (30), the battery management system (11) and the power generation unit (50), respectively, the energy management system (40) being configured to obtain real-time operating power of the power generation unit (50) and to perform a power distribution strategy based on power data of the load (60) fed back by the power detection unit (30): When the power data of the load (60) is lower than the lower limit value of the preset power operation interval of the power generation unit (50), the energy management system (40) controls the energy storage converter (20) to enter a charging state, and absorbs electric energy from the alternating current bus to increase the output load of the power generation unit (50), so that the actual output power of the power generation unit (50) is maintained in the preset power operation interval.
2. The energy storage system of claim 1, wherein the energy storage converter (20) is configured to employ a droop control strategy by monitoring the voltage magnitude and frequency of the ac bus and automatically adjusting the active and reactive power outputs of the energy storage converter (20) with a preset droop factor in response to power fluctuations of the load (60).
3. The energy storage system of claim 1, wherein the energy management system (40) is further configured to control the energy storage converter (20) to enter a discharge state when the total power of the load (60) exceeds an upper limit of the preset power operation interval of the power generation unit (50), assuming a load power exceeding the upper limit portion.
4. The energy storage system of claim 1, wherein the energy management system (40) is further configured to perform dynamic parameter adjustment by acquiring a state of charge of the battery module (10) in real time and dynamically modifying a sag curve parameter of the energy storage converter (20) in a virtual synchronous machine mode according to the state of charge value to change a response sensitivity of the energy storage converter (20) to a voltage amplitude or frequency change.
5. The energy storage system according to claim 1, wherein the preset power operation interval is set to 70% to 90% of the rated power of the power generation unit (50).
6. An energy storage device, characterized by comprising a housing (100) and an energy storage system according to any of claims 1-5 arranged on the housing (100).
7. A method of controlling an energy storage system, comprising the steps of: s1, establishing data interaction between an energy management system (40) and a controller of an external power generation unit (50), and acquiring real-time electrical parameters of the power generation unit (50); S2, controlling an energy storage converter (20) to operate in a virtual synchronous machine mode, following load fluctuation based on voltage-frequency droop characteristics, and monitoring total power of a load (60) in real time, comparing the total power of the load (60) with a preset power operation interval of a power generation unit (50), and when the total power of the load (60) is monitored to be lower than the lower limit value of the preset power operation interval, generating a charging instruction to be sent to the energy storage converter (20), and controlling a battery cluster (12) to charge so as to improve the load rate, so that the power generation unit (50) is maintained in the preset power operation interval; and/or generating a discharge instruction to compensate for a load power gap when it is monitored that the total power of the load (60) is higher than an upper limit value of the preset power operation interval.
8. The control method according to claim 7, characterized in that in step S2, in the process of controlling the battery cluster (12) to charge, a trend of change in the state of charge of the battery cluster (12) is calculated in real time, and when the state of charge reaches a preset overcharge prevention threshold value, a speed regulation instruction is sent to the controller of the power generation unit (50) through the energy management system (40), so that the mechanical power output of the power generation unit (50) is reduced.
9. The control method according to claim 7, characterized by further comprising the step of: s3, performing secondary regulation control for load power step change: When the step change of the power of the load (60) is monitored, the energy storage converter (20) automatically adjusts the output power based on the sagging characteristic to complete primary adjustment, and then the energy management system (40) recalculates the power set value of the energy storage converter (20) according to the total power data of the load (60) after the change and issues the power set value to complete secondary adjustment, so that the output power of the power generation unit (50) is locked in the preset power operation interval again.
10. The control method according to claim 7, characterized by further comprising the step of: S4, performing thermal runaway protection and electrical blocking: When a thermal runaway alarm signal is received, the energy management system (40) executes a bidirectional blocking strategy, namely blocking pulse output of the energy storage converter (20) on a direct current side and controlling a direct current breaker of the battery cluster (12) to be opened so as to cut off a direct current arc; on the alternating current side, an isolation instruction is sent to the power generation unit (50) through a communication interface, and the power generation unit (50) is controlled to be disconnected with an alternating current bus.

Description

Energy storage system, energy storage device and control method of energy storage system Technical Field The present application relates to the field of electric energy storage systems, and in particular, to an energy storage system, an energy storage device, and a control method of the energy storage system. Background In the scenes of engineering machinery operation, drilling platforms and the like, the fluctuation characteristic of load power is obvious, particularly in the processes of lifting a drill rod, starting high-power equipment and the like, instantaneous surge peak load can occur, and the load power is relatively stable under the conventional working condition. The power supply of the current scene mainly depends on power generation units such as a diesel generator set, and in order to cope with transient peak load demands, the power generation units with enough power redundancy need to be configured to run on line for a long time. The existing power supply scheme has obvious performance and cost contradiction that on one hand, a high-power generation unit configured for covering peak load is in a low-load operation state under most normal working conditions to form a low-efficiency mode of a large maraca trolley, so that fuel consumption is increased and power generation efficiency is reduced, on the other hand, when the power generation unit is operated under an unsteady working condition with frequently suddenly changed load, response speed is difficult to match load change, voltage and frequency fluctuation are easy to cause, operation safety of electric drive equipment is influenced, mechanical abrasion of a unit is also increased, maintenance frequency and shutdown risk are improved, and comprehensive operation and maintenance cost is increased. In addition, the traditional scheme lacks a flexible power buffering and regulating mechanism, and cannot realize the cooperation of efficient operation of the power generation unit and stable power supply of peak load. In order to alleviate the above problems, attempts have been made in the industry to improve the control strategy of the power generation unit or to add redundant configuration, but the contradiction between load fluctuation and efficient operation of the power generation unit cannot be solved, and there is still room for improvement in response speed, power adjustment accuracy and comprehensive cost control. Therefore, a power supply scheme capable of rapidly responding to load fluctuation and flexibly adjusting power distribution is needed, and the power generation unit is maintained in a high-efficiency operation interval while the stability of peak load power supply is ensured, so that the synchronous optimization of power supply reliability and economy is realized. Disclosure of Invention In order to solve the technical problems, the application provides an energy storage system, an energy storage device and a control method of the energy storage system. In a first aspect, the present application provides an energy storage system, which adopts the following technical scheme: An energy storage system is suitable for being connected to an alternating current bus in parallel to a power generation unit to supply power to a load, the energy storage system comprises a battery module, an energy storage converter, a power detection unit and an energy management system, the battery module comprises a battery management system and a battery cluster, the direct current side of the energy storage converter is connected with the battery cluster, the alternating current side of the energy storage converter is connected with the alternating current bus and is configured to operate in a virtual synchronous machine mode, the power detection unit is arranged at an input end of the alternating current bus or the load and is used for collecting power data of the load, the energy management system is respectively connected with the energy storage converter, the power detection unit, the battery management system and the power generation unit in a communication mode, the energy management system is configured to obtain real-time operation power of the power generation unit, and execute a power distribution strategy based on the power data of the load fed back by the power detection unit, when the power data of the load is lower than the lower limit value of a preset power operation interval of the power generation unit, the energy storage converter is controlled to enter a charged state, and electric energy is absorbed from the alternating current bus to increase the output load of the power generation unit, so that the actual output power of the power generation unit is maintained within the preset power operation interval. By adopting the technical scheme, the energy storage system and the power generation unit are connected in parallel to cooperatively work, and by means of the virtual synchronous machine mode and the power distribution strategy