Method for power distribution in electricity-hydrogen hybrid energy storage system in microgrid, device, and medium

1 . A method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid, wherein the electricity-hydrogen hybrid energy storage system comprises an electrochemical energy storage system and a hydrogen energy storage system, and the method comprises:

acquiring a current operating power of the microgrid, a current state of charge (SOC) value of the electrochemical energy storage system, and a current state of health (SOH) value of the hydrogen energy storage system;

decomposing the current operating power according to a grid connection requirement to obtain a grid connection power and a to-be-smoothed power, in response to an absolute value of the current operating power being greater than a preset power threshold;

distributing the to-be-smoothed power according to the current SOC value and the current SOH value with a goal of minimizing operating costs to obtain a first optimal charge/discharge power of the electrochemical energy storage system and a second optimal charge/discharge power of the hydrogen energy storage system; wherein the operating costs are solved by the following expression:

C

u

⁢

s

⁢

e

=

C

p

⁢

c

b

⁢

a

⁢

P

ba_set

(

t

)

+

C

v

⁢

c

b

⁢

a

⁢

∫

0

T

s

P

ba_set

(

t

)

⁢

dt

+

C

p

⁢

c

h

⁢

e

⁢

P

he_set

(

t

)

+

C

v

⁢

c

h

⁢

e

⁢

∫

0

T

s

P

he_set

(

t

)

⁢

dt

wherein C use is the operating costs,

C

p

⁢

c

b

⁢

a

is a unit power cost of the electrochemical energy storage system,

C

v

⁢

c

b

⁢

a

is a unit capacity cost of the electrochemical energy storage system,

C

p

⁢

c

h

⁢

e

is a unit power cost of the hydrogen energy storage system,

C

v

⁢

c

h

⁢

e

is a unit capacity cost of the hydrogen energy storage system, T s is a sampling period, P ba_set (t) is the first charge/discharge power of the electrochemical energy storage system, and P he_set (t) is the second charge/discharge power of the hydrogen energy storage system;

determining a protection strategy according to the to-be-smoothed power, a preset SOC operating range of the electrochemical energy storage system, and the current SOC value;

controlling the microgrid to connect to a grid according to the grid connection power, controlling the electrochemical energy storage system to operate according to the first optimal charge/discharge power, controlling the hydrogen energy storage system to operate according to the second optimal charge/discharge power, and adjusting an SOC state of the electrochemical energy storage system according to the protection strategy;

wherein the preset SOC operating range of the electrochemical energy storage system comprises a high SOC range, a normal SOC range, and a low SOC range, and determining a protection strategy according to the to-be-smoothed power, a preset SOC operating range of the electrochemical energy storage system, and the current SOC value comprises:

in response to the to-be-smoothed power being greater than zero and the current SOC value falling within the high SOC range, determining the protection strategy as: controlling the electrochemical energy storage system to discharge until an SOC value of the electrochemical energy storage system drops to the normal SOC range, electric energy generated by the electrochemical energy storage system being supplied to the hydrogen energy storage system; and

in response to the to-be-smoothed power being less than zero and the current SOC value falling within the low SOC range, determining the protection strategy as: controlling the electrochemical energy storage system to be charged until an SOC value of the electrochemical energy storage system rises to the normal SOC range, electric energy required by the electrochemical energy storage system being supplied by the hydrogen energy storage system.

2 . The method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 , wherein the current operating power of the microgrid is obtained by:

acquiring an electricity-generating power of a photovoltaic system in the microgrid and an electricity-consuming power of a direct current (DC) load in the microgrid, and determining a difference between the electricity-generating power and the electricity-consuming power as the current operating power of the microgrid.

3 . The method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 , wherein decomposing the current operating power according to a grid connection requirement to obtain a grid connection power and a to-be-smoothed power comprises:

processing the current operating power using a variational mode decomposition algorithm, and during the processing, optimizing a mode decomposition number and a penalty factor required by the variational mode decomposition algorithm using a grey wolf optimizer to obtain a plurality of optimal mode components;

dividing the plurality of optimal mode components according to the grid connection requirement to obtain a plurality of low-frequency optimal mode components and a plurality of high-frequency optimal mode components;

combining the plurality of low-frequency optimal mode components to obtain the grid connection power; and

combining the plurality of high-frequency optimal mode components to obtain the to-be-smoothed power.

4 . The method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 , wherein distributing the to-be-smoothed power according to the current SOC value and the current SOH value with a goal of minimizing operating costs to obtain a first optimal charge/discharge power of the electrochemical energy storage system and a second optimal charge/discharge power of the hydrogen energy storage system comprises:

determining a fitness function with the goal of minimizing the operating costs;

determining the first charge/discharge power of the electrochemical energy storage system and the second charge/discharge power of the hydrogen energy storage system as target variables to be optimized;

determining a power balance constraint condition according to the target variables and the to-be-smoothed power;

determining an SOC constraint condition according to the target variables and the current SOC value;

determining an SOH constraint condition according to the target variables and the current SOH value; and

performing iterative optimization of the target variables using an improved genetic algorithm according to the fitness function, the power balance constraint condition, the SOC constraint condition, and the SOH constraint condition, and introducing an adaptive probability function for crossover and mutation operations in each iteration process, to obtain the first optimal charge/discharge power of the electrochemical energy storage system and the second optimal charge/discharge power of the hydrogen energy storage system.

5 . The method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 4 , wherein the power balance constraint condition comprises: defining a sum of the first charge/discharge power of the electrochemical energy storage system and the second charge/discharge power of the hydrogen energy storage system as the to-be-smoothed power.

6 . The method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 , further comprising: maintaining an operating status of the microgrid unchanged, in response to the absolute value of the current operating power being less than or equal to the preset power threshold.

7 . A computer device, comprising a memory and a processor, wherein the memory is configured for storing a computer program, and the processor is configured for executing the computer program to perform the method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 .

8 . A computer-readable storage medium, having a computer program stored thereon, wherein the computer program, when executed by a processor, causes the processor to perform the method for power distribution in an electricity-hydrogen hybrid energy storage system in a microgrid of claim 1 .