CN-121984101-A - Multistage power control method and system of alternating current-direct current integrated energy storage unit

CN121984101ACN 121984101 ACN121984101 ACN 121984101ACN-121984101-A

Abstract

The application provides a multistage power control method of an alternating current-direct current integrated energy storage unit, which comprises the steps that a unit controller sets a single optimal operation power value W1 and a single suboptimal operation power value W2 of an energy storage converter, after the unit controller receives a power instruction W, the power instruction W is respectively compared with a total optimal operation power value n1W1 and a total suboptimal operation power value n1W2 of the energy storage converter in a normal fault-free state, and the number of the energy storage converters required to enter the operation state and the power distributed to each energy storage converter entering the operation state are calculated according to a comparison result. The application also provides a multistage power control system of the alternating current-direct current integrated energy storage unit. The multistage power control method of the alternating current-direct current integrated energy storage unit can realize simultaneous control of all energy storage converters, and the loss of energy storage equipment is minimum.

Inventors

LIU QINGYUN
HUA XINQIANG
JIAN HUI
JIANG SHUNPING
DING YONG
LIAN JIANYANG

Assignees

思源清能电气电子有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (11)

1. The multistage power control method of the alternating current-direct current integrated energy storage unit is characterized by comprising a multistage power control system for the alternating current-direct current integrated energy storage unit, wherein the multistage power control system of the alternating current-direct current integrated energy storage unit comprises a unit controller and n energy storage converters, each energy storage converter is in communication connection with the unit controller, and n is a non-zero positive integer; the multistage power control method of the alternating current-direct current integrated energy storage unit comprises the following steps: The unit controller sets a single optimal operation power value W1 and a single suboptimal operation power value W2 of the energy storage converter; After the unit controller receives a power command W, the power command W is respectively compared with a total optimal operation power value n1W1 and a total optimal operation power value n1W2 of n1 energy storage converters in a normal fault-free state, wherein n1 is a non-zero positive integer less than or equal to n, and at least n1 of the n energy storage converters are in the normal fault-free state; And calculating the number of energy storage converters required to enter the running state and the power distributed to each energy storage converter entering the running state according to the comparison result, wherein the unit controller transmits a state switching signal and a power value to each energy storage converter, each energy storage converter receives and executes an instruction and then transmits a standby/running state and a real-time power value to the unit controller, and the unit controller compares the standby/running state and the real-time power value with the state switching signal and the power value transmitted by the unit controller after receiving the instruction, so that the instruction execution is ensured to be error-free.
2. The multistage power control method of an ac/dc integrated energy storage unit according to claim 1, wherein when W is less than or equal to n1W1, the unit controller calculates the number n2 of energy storage converters to be switched to an operation state according to the principle that the operation power value of a single energy storage converter is less than or equal to W1, n2 is a positive integer less than or equal to n1, issues n2 operation state switching instructions to the energy storage converters, sequentially distributes W1 power to the energy storage converters switched to the operation state according to the principle of preferentially distributing the optimal operation power value W1, so that the energy storage converters enter the optimal operation power state, and the last energy storage converter distributes the residual power.
3. The method for controlling the multi-level power of the ac/dc integrated energy storage unit according to claim 1, wherein when n1W1< W is less than or equal to n1W2, the unit controller issues n1 operation state switching instructions to the energy storage converters, and distributes the n1 operation state switching instructions to the energy storage converters according to the combination of the optimal operation power value W1 and the optimal operation power value W2, so that the energy storage converters enter the optimal operation power state or the optimal operation power state, and the last energy storage converter distributes the remaining power.
4. The method for controlling the multi-stage power of the ac/dc integrated energy storage unit according to claim 1, wherein when W > n1W1, the unit controller issues n1 operation state switching instructions to the energy storage converters, and distributes power to each of the energy storage converters as required according to a power balance distribution principle, so that each of the energy storage converters enters a balanced power state.
5. The multi-stage power control method of an ac/dc integrated energy storage unit according to claim 1, wherein the unit controller fixedly allocates numbers 1 to n to the energy storage converters according to the port positions of the energy storage converters connected to the unit controller.
6. The method for controlling the multi-stage power of the ac/dc integrated energy storage unit according to claim 5, wherein when W is equal to or less than n1W1, according to the principle of preferentially allocating the optimal operation power value W1, W1 power is sequentially allocated to the energy storage converters switched to the operation state according to the number size, so that the energy storage converters enter the optimal operation power state.
7. The method according to claim 5, wherein when n1W1< W is less than or equal to n1W2, the energy storage power is allocated to the energy storage converter according to the combination of the optimal operation power value W1 and the optimal operation power value W2, and the energy storage converter is adaptively allocated according to the number of the energy storage converter, so that the energy storage converter enters an optimal operation power state or an optimal operation power state.
8. A multistage power control system of an alternating current-direct current integrated energy storage unit is characterized by comprising a unit controller and n energy storage converters, wherein each energy storage converter is in communication connection with the unit controller, and n is a non-zero positive integer; the multistage power control system of the alternating current-direct current integrated energy storage unit further comprises: The set controller sets a single optimal operation power value W1 and a single suboptimal operation power value W2 of the energy storage converter; The comparison module is used for comparing the power command W with a total optimal operation power value n1W1 and a total optimal operation power value n1W2 of the energy storage converters in a normal fault-free state respectively after the unit controller receives the power command W, wherein n1 is a non-zero positive integer less than or equal to n, and at least n1 of the n energy storage converters are in a normal fault-free state; The distribution module calculates the number of energy storage converters required to enter the running state and the power distributed to each energy storage converter entering the running state according to the comparison result, the unit controller transmits a state switching signal and a power value to each energy storage converter, each energy storage converter receives and executes an instruction and then transmits a standby/running state and a real-time power value to the unit controller, and the unit controller compares the standby/running state and the real-time power value with the state switching signal and the power value transmitted by the unit controller after receiving the instruction, so that the instruction execution is ensured to be error-free.
9. The system of claim 8, wherein when the configured energy storage system is of small capacity, the system comprises a unit controller, a coordination controller and n energy storage converters, the coordination controller is connected with the unit controller, the coordination controller controls the unit controller, each energy storage converter is in communication connection with the unit controller, and n is a non-zero positive integer.
10. The system of claim 8, wherein when the configured energy storage system is of small capacity, the system comprises a coordination controller, n energy storage converters, each of the energy storage converters being communicatively connected to the coordination controller, and n being a non-zero positive integer.
11. The system of claim 8, wherein when the configured energy storage system has a large capacity, the system comprises a plurality of unit controllers, a coordination controller and n energy storage converters, the unit controllers and the coordination controller are connected through optical fibers to form a ring network, the unit controllers are controlled by the coordination controller, each energy storage converter is connected with the unit controllers in a communication way, and n is a non-zero positive integer.

Description

Multistage power control method and system of alternating current-direct current integrated energy storage unit Technical Field The application relates to the technical field of power supplies, in particular to a multistage power control method and system of an alternating current-direct current integrated energy storage unit. Background With the continuous growth of energy demands and increasingly prominent environmental problems, the development and utilization of new energy has become an important trend in the field of global energy development. Because of the instability and intermittence of the new energy, the large-scale access of the new energy to the power grid can cause great influence on the operation of the power grid. The energy storage technology can effectively solve the defect of new energy, so that the energy storage technology is widely applied to electric power systems to balance supply and demand differences, improve renewable translation and improve the reliability and stability of a power grid. The energy storage converter is a core device of energy storage technology, is power electronic equipment capable of realizing electric energy conversion and control, can convert direct current electric energy stored in energy storage equipment (such as a lithium battery pack, a super capacitor and the like) into alternating current electric energy to be output to a power grid or provided for a load to be used, and can also convert the alternating current electric energy in the power grid into direct current electric energy to be stored in the energy storage equipment. The energy supply system has the core functions of realizing bidirectional flow of energy, discharging to a power grid and charging from the power grid, thereby effectively balancing the supply and demand relation of a power system. How to control the energy storage converter to perform energy conversion better under the condition of meeting the use requirement, and prolong the service life of equipment at the same time is a problem which needs to be solved by the ordinary person in the art. The application publication number CN119834321a discloses a parallel operation control method and system for an energy storage converter, through a master energy storage converter and N-1 slave energy storage converters (N is a positive integer greater than or equal to 2) connected in parallel between a power grid end and a load end, an output current of the load end of the energy storage converter is obtained, a difference between the output current and a preset current threshold is judged by the master energy storage converter, a state switching signal is generated, and an operation state of the slave energy storage converters is switched, so that the number of the energy storage converters in a grid-connected mode/grid-disconnected mode can be automatically adjusted according to the change of load capacity, the conversion efficiency and the self-adaptive capacity of the energy storage converters are improved, the system benefit is maximized while the load demand of a user is met, however, delay and hysteresis are not described in the issuing of signals for the slave grid-connected/grid-disconnected operation mode switching signal of the master energy storage converters, and how to realize simultaneous control of all the energy storage converters, standby/operation state switching control of the energy storage converters and power control methods are not described. Disclosure of Invention The application provides a multistage power control method and a multistage power control system of an alternating current-direct current integrated energy storage unit, which aim to solve the problems of how to realize simultaneous control of all energy storage converters, switching control of standby/running states of the energy storage converters and a power control method. In order to solve the technical problems, the application provides a multistage power control method of an alternating current-direct current integrated energy storage unit, which is used for a multistage power control system of the alternating current-direct current integrated energy storage unit, wherein the multistage power control system of the alternating current-direct current integrated energy storage unit comprises a unit controller and n energy storage converters, each energy storage converter is in communication connection with the unit controller, and n is a non-zero positive integer; the multistage power control method of the alternating current-direct current integrated energy storage unit comprises the following steps: The unit controller sets a single optimal operation power value W1 and a single suboptimal operation power value W2 of the energy storage converter; After the unit controller receives a power command W, the power command W is respectively compared with a total optimal operation power value n1W1 and a total optimal operation power value n1W2 of n1 energy sto