A shore power box control system for a port terminal and its control method

Abstract

The present invention discloses a control system and a control method for an onshore power supply box at a port terminal, which relates to the technical field of onshore power supply box control. By obtaining the historical data sequence of the active power at the load end of the onshore power supply system at the terminal, constructing the state space of the active power at the load end, calculating the expected value of the active power at the load end in the next time period by using the Markov chain model, constructing a monitoring model of the active power at the load end with a time length of λ according to the obtained expected value, classifying the change state of the active power at the load end into a stable change and a change exceeding the threshold by using the monitoring model, obtaining the performance index parameters of the energy storage system of the onshore power supply system at the terminal at the current time t, calculating the operation state evaluation value at the current time, determining its operation condition state, and collecting the state of charge of the energy storage system at the current time t in real time, the operation strategy of the onshore power supply system at the terminal is determined according to the determination result of the change state of the active power at the load end and the operation condition state of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of onshore power box control, and particularly to an onshore power box control system for a port terminal and a control method thereof. Background Technique

[0002] An onshore power box is a dedicated ship power supply connection device for port terminals, providing a fast and safe standard onshore power interface for berthed ships, and realizing ship branch cable power supply, data collection, charging and settlement. The port energy conservation and emission reduction policy has promoted the development of the onshore power supply system for port ships. Using onshore power by ships is an effective emission reduction method during ship berthing, which can reduce emissions of sulfur oxides, nitrogen oxides, particulate matter, etc., and reduce noise pollution. Generally, in the design stage of the onshore power system at the terminal, for the selection of its system capacity, it is necessary to determine according to various factors such as berth type, number of berths, maximum berthed ship, and power consumption requirements of ship equipment, and introduce a coincidence factor parameter, which represents the number of ships simultaneously berthed at the port berth, to estimate the capacity of the onshore power system at the terminal.

[0003] However, due to the randomness of the departure and arrival times of ships in the port, and the power consumption requirements of each berthed ship being determined by the tonnage and type of the ship, with large differences between them, the ship load power changes significantly during the process of grid access and disconnection, causing power quality problems such as grid-side voltage fluctuations. This not only increases the power loss of the grid and poses a severe test to the grid, but also the strong fluctuating load power is likely to cause a series of problems such as misoperation of protection devices such as relay protectors and overheating of the transformer winding leads, reducing the reliability of the operation of the onshore power system. For this reason, we propose an onshore power box control system for a port terminal and a control method thereof. Summary of the Invention

[0004] The main purpose of the present invention is to provide an onshore power box control system for a port terminal and a control method thereof, which can effectively solve the problems in the background technique.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An onshore power box control method for a port terminal includes:

[0007] Obtain the historical data sequence Ω of the active power at the load end of the onshore power system at the terminal, and construct the load end active power state space S = {S 1 , S 2 ,..., S k}, where S k represents the k-th level state of the active power at the load end. Calculate the expected value of the active power at the load end in the next time period using the Markov chain model. The acquisition process includes the following steps:

[0008] According to the designed capacity P of the onshore power supply system of the wharf s The active power at the load end is equally divided into k levels, and the stepped intervals of the active power at the load end are made to correspond one by one with the active power levels at the load end, so as to obtain the state space S of the active power at the load end = {S 1 , S 2 ,..., S k};

[0009] Calculate the level state transition probability in the historical data sequence Ω of the active power at the load end. The calculation formula is: In the formula, represents the transition probability that the active power level state at the load end transfers from the i-th level state to the j-th level state in one step; represents the frequency that the active power level state at the load end transfers from the i-th level state to the j-th level state in one step in the sequence Ω; S i→j represents that the active power at the load end transfers from the i-th level state to the j-th level state in one step, where i, j ∈ k;

[0010] Construct a level state transition probability matrix according to the obtained level state transition probability

[0011] Obtain the active power p at the load end at the current time t t , determine the level state S t of the current active power p at the load end t , and calculate the level expectation E(S t ) of the active power at the load end at the t + 1 moment according to the constructed level state transition probability matrix. The calculation formula is: where t, q ∈ k;

[0012] Take the calculated level expectation E(S t ) as the level state S t+1 of the active power at the load end at the t + 1 moment. Respectively generate random numbers ε t and ε t+1 that follow a uniform distribution according to the level state S t and the level state S t+1 , and ε t , ε t+1 ∈ [0, 1], and ε t is independent of ε t+1 ;

[0013] Through the formula: Calculate and obtain the expected value p t+1 of the active power at the load end at the t + 1 moment;

[0014] Construct a monitoring model of the active power at the load end with a time length of λ according to the obtained expected value, and classify the change state of the active power at the load end into two types: stable change and over-threshold change by using the monitoring model;

[0015] Evaluate the operating condition state of the energy storage system of the quay shore power system, and collect the state of charge SOC of the energy storage system at the current time t in real time t Determine the operation strategy of the quay shore power system according to the judgment result of the change state of the active power at the load end and the operating condition state of the energy storage system;

[0016] Among them, the expression of the monitoring model is:

[0017]

[0018] In the formula, f(p t+r ) is the determination function of the active power change at the load end, and when f(p t ) = 0, it is determined that the active power at the load end is in a stable change state; when f(p t ) = 1, it is determined that the active power at the load end is in an over-threshold change state; η is a constant coefficient greater than 1; Δp k is the reasonable threshold of the active power change amount; p t is the active power at the load end at the current time t; p t+r is the active power at the load end at the (t + r)-th moment.

[0019] The method further includes the following steps:

[0020] Obtain the performance index parameters of the energy storage system of the quay shore power system at the current time t, and according to the formula: Calculate its operation state evaluation value at the current moment. In the formula, As t represents the operation state evaluation value of the energy storage system at time t; R t represents the reliability of the energy storage system at time t; SOH t represents the health degree of the energy storage system at time t; is a constant coefficient, and R t The calculation formula of is:

[0021]

[0022] In the formula, M represents the total number of battery clusters connected in parallel in the energy storage system; r m represents the operation reliability of the m-th battery cluster connected in parallel in the energy storage system.

[0023] SOH t The calculation formula of is:

[0024]

[0025] In the formula, s tq represents the evaluation value of the q-th performance index of the energy storage system at time t; s qmax represents the sampling optimal value of the q-th performance index within the time length λ; s qmin represents the sampling worst value of the q-th performance index within the time length λ, and the performance index includes at least one of internal resistance size, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed;

[0026] Set the lower limit value As of the operating state evaluation of the energy storage system min , and determine the operating condition state of the energy storage system according to the quantitative relationship between As min and As t . The determination principle is:

[0027] If As t ≥As min , then the energy storage system participates in the regulation process of the active power at the load end;

[0028] If As t <As min , then the energy storage system does not participate in the regulation process of the active power at the load end.

[0029] Among them, the determination principle of the operation strategy of the quay shore power system is:

[0030] In the case where the energy storage system can participate in the regulation process of the active power at the load end:

[0031] When the active power at the load end is in a steady change state:

[0032] If SOC min ≤SOC t ≤SOC max , then the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 ;

[0033] If SOC t <SOC min , then charge the energy storage system, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 ;

[0034] If SOC t >SOC max , then discharge the energy storage system, and the active power p at the load end at time t + 1 is jointly borne by the energy storage system and the grid side t+1 ;

[0035] When the active power at the load end is in a state of exceeding the threshold change, and when p t+1 > p t :

[0036] If SOC min ≤ SOC t ≤ SOC max then discharge the energy storage system, and the energy storage system and the grid side jointly bear the active power p t+1 at the load end at time t + 1;

[0037] If SOC t < SOC min then the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p t+1 at the load end at time t + 1;

[0038] If SOC t > SOC max then discharge the energy storage system, and the energy storage system and the grid side jointly bear the active power p t+1 at the load end at time t + 1;

[0039] When the active power at the load end is in a state of exceeding the threshold change, and when p t+1 ≤ p t :

[0040] If SOC min ≤ SOC t ≤ SOC max then charge the energy storage system, and the energy storage system does not participate in bearing the active power p t+1 at the load end at time t + 1;

[0041] If SOC t < SOC min then charge the energy storage system, and the energy storage system does not participate in bearing the active power p t+1 at the load end at time t + 1;

[0042] If SOC t > SOC max then discharge the energy storage system, and the energy storage system does not participate in bearing the active power p t+1 .

[0043] A shore power box control system for a port terminal, comprising a historical data acquisition module, a model construction module, a power change state classification module, an energy storage system state evaluation module, a real-time data acquisition module, an energy storage system operating condition state evaluation module, and a shore power system operation strategy formulation module;

[0044] The historical data acquisition module is used to acquire the historical data sequence Ω of the active power at the load end of the quay shore power system, and according to the designed capacity P of the quay shore power system s The active power at the load end is equally divided into k levels, and the stepped interval of the active power at the load end is made to correspond one by one with the active power level at the load end, and the state space S of the active power at the load end is constructed as S = {S 1 , S 2 ,..., S k};

[0045] The model construction module is used to calculate the expected value of the active power at the load end in the next time period by using the Markov chain model;

[0046] The power change state classification module is used to construct a monitoring model of the active power at the load end with a time length of λ according to the obtained expected value, and classify the change state of the active power at the load end into a stable change and a change exceeding the threshold by using the monitoring model;

[0047] The energy storage system state evaluation module is used to acquire the performance index parameters of the energy storage system of the quay shore power system at the current moment t, and calculate its operation state evaluation value at the current moment;

[0048] The real-time data acquisition module is used to collect the state of charge SOC of the energy storage system at the current moment t in real time t ;

[0049] The energy storage system working condition state evaluation module is used to evaluate the working condition state of the energy storage system according to the quantitative relationship between the set lower limit value As min of As t ;

[0050] The shore power system operation strategy formulation module is used to determine the operation strategy of the quay shore power system according to the determination result of the change state of the active power at the load end and the working condition state of the energy storage system;

[0051] The system further includes a memory, a processor, and a computer program stored on the memory and executable on the processor.

[0052] The present invention has the following beneficial effects

[0053] Compared with the prior art, the technical solution of the present invention obtains the historical data sequence of the active power at the load end of the quay shore power system, constructs the state space of the active power at the load end, calculates the expected value of the active power at the load end in the next time period by using the Markov chain model, constructs a monitoring model of the active power at the load end with a time length of λ according to the obtained expected value, classifies the change state of the active power at the load end into a stable change and a change exceeding the threshold by using the monitoring model, obtains the performance index parameters of the energy storage system of the quay shore power system at the current time t, calculates the operation state evaluation value at the current time, determines its operation condition state, and collects the state of charge of the energy storage system at the current time t in real time. According to the determination result of the change state of the active power at the load end and the operation condition state of the energy storage system, the operation strategy of the quay shore power system is determined, which can reduce the influence degree of the large change of the ship load power on the grid side voltage during the grid connection and disconnection process, and enhance the reliability of the operation of the shore power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a flowchart of a control system and a control method for a shore power box of a port terminal according to the present invention;

[0055] Figure 2 is a structural block diagram of a control system for a shore power box of a port terminal according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] The following further describes the present invention in conjunction with the specific embodiments. Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as limiting the present invention. In order to better illustrate the specific embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of the actual product.

[0057] The specific implementation process of the technical solution of the present invention includes the following steps:

[0058] Step 1: Obtain the historical data sequence Ω of the active power at the load end of the quay shore power system. According to the design capacity P of the quay shore power system s equally divide the active power at the load end into k levels, and make the stepped interval of the active power at the load end correspond one-to-one with the active power level at the load end, so as to construct the state space of the active power at the load end S = {S 1 , S 2 ,..., S k}, where S k represents the state of the kth level of the active power at the load end;

[0059] Step 2: Calculate the expected value of the active power at the load end in the next time period by using the Markov chain model. The obtaining process includes the following steps:

[0060] Step 21: Calculate the grade state transition probability in the historical data sequence Ω of the active power at the load end. The calculation formula is as follows: In the formula, represents the transition probability that the active power grade state at the load end transfers from the i-th grade state to the j-th grade state in one step; represents the frequency that the active power grade state at the load end in the sequence Ω transfers from the i-th grade state to the j-th grade state in one step; S i→j represents that the active power at the load end transfers from the i-th grade state to the j-th grade state in one step, where i, j ∈ k;

[0061] Step 22: Construct a grade state transition probability matrix based on the obtained grade state transition probability

[0062] Step 23: Obtain the active power p at the load end at the current time t t , and determine the grade state S of the current active power p at the load end t . According to the constructed grade state transition probability matrix, calculate the grade expectation E(S t ) of the active power at the load end at the t + 1 moment. The calculation formula is as follows: t where t, q ∈ k;

[0063] Step 24: Use the calculated grade expectation E(S t ) as the grade state S of the active power at the load end at the t + 1 moment t+1 . Respectively, generate random numbers ε t and ε t+1 that follow a uniform distribution according to the grade state S t and the grade state S t+1 , and ε t , ε t+1 ∈ [0, 1], and ε t is independent of ε t+1 ;

[0064] Step 25: Calculate and obtain the expected value p of the active power at the load end at the t + 1 moment through the formula: t+1 ;

[0065] Step 3: Construct a monitoring model for the active power at the load end with a time length of λ based on the obtained expected value, and use the monitoring model to classify the change state of the active power at the load end into two types: stable change and over-threshold change; among them, the expression of the monitoring model is:

[0066]

[0067] In the formula, f(p t+r ​​) is the active power change determination function at the load end. When f(p t ) = 0, it is determined that the active power at the load end is in a stable change state; when f(p t ) = 1, it is determined that the active power at the load end is in a state of change exceeding the threshold; η is a constant coefficient greater than 1; Δp k is the reasonable threshold of the active power change amount; p t is the active power at the load end at the current time t; p t+r is the active power at the load end at the (t + r)-th moment;

[0068] Step 4: Evaluate the operating condition state of the energy storage system of the quay shore power system; the specific process includes:

[0069] Step 41: Obtain the performance index parameters of the energy storage system of the quay shore power system at the current time t, and according to the formula: Calculate its operating state evaluation value at the current moment. In the formula, As t represents the operating state evaluation value of the energy storage system at time t; R t represents the reliability of the energy storage system at time t; SOH t represents the health degree of the energy storage system at time t; is a constant coefficient, and R t The calculation formula of is:

[0070]

[0071] In the formula, M represents the total number of battery clusters connected in parallel in the energy storage system; r m represents the operating reliability of the m-th battery cluster connected in parallel in the energy storage system.

[0072] SOH t The calculation formula of is:

[0073]

[0074] In the formula, s tq represents the q-th performance index evaluation value of the energy storage system at time t; s qmax represents the sampling optimal value of the q-th performance index within the time length λ; s qmin represents the sampling worst value of the q-th performance index within the time length λ. The performance indexes include at least one of internal resistance size, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed;

[0075] Step 42: Set the lower limit value As min of the operating state evaluation of the energy storage system. According to As min and As tThe quantitative relationship determines the operating condition state of the energy storage system, and the determination principle is as follows:

[0076] If As t ≥As min , it indicates that the operating state of the energy storage system is good and it can participate in the regulation process of the active power at the load end;

[0077] If As t <As min , it indicates that the operating state of the energy storage system is not good and it cannot participate in the regulation process of the active power at the load end

[0078] Step 5: Real-time collect the state of charge SOC of the energy storage system at the current moment t t , and determine the operation strategy of the onshore power system of the wharf according to the determination result of the change state of the active power at the load end and the operating condition state of the energy storage system; among them, the determination principle of the operation strategy of the onshore power system of the wharf is as follows:

[0079] In the case where the energy storage system can participate in the regulation process of the active power at the load end:

[0080] When the active power at the load end is in a steady change state:

[0081] If SOC min ≤SOC t ≤SOC max , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at the moment t + 1 t+1 ;

[0082] If SOC t <SOC min , charge the energy storage system, and the energy storage system does not participate in bearing the active power p at the load end at the moment t + 1 t+1 ;

[0083] If SOC t >SOC max , discharge the energy storage system, and the energy storage system and the grid end jointly bear the active power p at the load end at the moment t + 1 t+1 ;

[0084] When the active power at the load end is in a state of exceeding the threshold change, and when p t+1 >p t :

[0085] If SOC min ≤SOC t ≤SOC max , discharge the energy storage system, and the energy storage system and the grid end jointly bear the active power p at the load end at the moment t + 1 t+1 ;

[0086] If the state of charge (SOC) t <SOC min , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 ;

[0087] If the state of charge (SOC) t >SOC max , the energy storage system discharges, and the energy storage system and the grid side jointly bear the active power p at the load end at time t + 1 t+1 ;

[0088] When the active power at the load end is in a state of exceeding the threshold, and when p t+1 ≤p t :

[0089] If the state of charge (SOC) min ≤SOC t ≤SOC max , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 ;

[0090] If the state of charge (SOC) t <SOC min , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 ;

[0091] If the state of charge (SOC) t >SOC max , the energy storage system discharges, and the energy storage system does not participate in bearing the active power p at the load end at time t + 1 t+1 .

[0092] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A port terminal shore power box control method, characterized in that: include: Obtain the historical data sequence Ω of the active power at the load end of the terminal shore power system, and construct the load end active power state space S = {S1, S2, ..., S k }, where S k It is expressed as the active power at the load end being the kth level state, and the expected value of the active power at the load end in the next period is calculated using the Markov chain model; A load-side active power monitoring model with a time length of λ is constructed according to the obtained expected value, and the load-side active power change state is classified into two types: a steady change and an over-threshold change by using the monitoring model; Evaluate the operating status of the energy storage system of the terminal shore power system, and collect the state of charge (SOC) of the energy storage system at the current time t in real time t , according to the determination result of the active power change state at the load end and the operating condition of the energy storage system, determine the operation strategy of the terminal shore power system; The expression of the monitoring model is: In the formula, f(p t+r ) is the load end active power change judgment function, and when f(p t )=0, it is determined that the active power at the load end is in a stable changing state; when f(p t )=1, it is determined that the active power at the load end is in an over-threshold change state; η is a constant coefficient greater than 1; Δp k is the reasonable threshold value of active power change; p t is the active power at the load end at the current time t; p t+r is the active power at the load end at the time t+r.

2. A port terminal shore power box control method according to claim 1, characterized in that: The method further comprises the following steps: Obtain the performance index parameters of the energy storage system of the terminal shore power system at the current time t, according to the formula: Calculate the evaluation value of its operating status at the current moment, where As t Represented as the operating status evaluation value of the energy storage system at time t; R t It is expressed as the reliability of the energy storage system at time t; SOH t Represents the health of the energy storage system at time t; is a constant coefficient, and Set the lower limit of the energy storage system operation status evaluation As min , according to As min With As t The quantitative relationship determines the operating state of the energy storage system, and the determination principle is: If As t ≥As min , then the energy storage system participates in the regulation process of active power at the load end; If As t <As min , the energy storage system does not participate in the regulation process of active power at the load end.

3. A port terminal shore power box control method according to claim 1, characterized in that: The process of obtaining the expected value of active power at the load end includes the following steps: According to the design capacity P of the terminal shore power system s The load-side active power is equally divided into k levels, and the step-wise intervals of the load-side active power correspond to the load-side active power levels one by one, thereby obtaining the load-side active power state space S = {S1, S2, ..., S k }; Calculate the level state transition probability in the historical data sequence Ω of the active power at the load end, and the calculation formula is: In the formula, It is expressed as the transition probability of the active power level state at the load end from the i-th level state to the j-th level state in one step; It is expressed as the frequency of the active power level state of the load end in the sequence Ω being transferred from the i-th level state to the j-th level state through one step; S i→j It is expressed as the active power at the load end is transferred from the i-th level state to the j-th level state in one step, i, j∈k; Construct the level state transition probability matrix based on the obtained level state transition probability Get the active power p of the load at the current time t t , determine the current load end active power p t Grade status S t , calculate the expected level of active power at the load end at time t+1 according to the constructed level state transition probability matrix E(S t ), the calculation formula is: Among them, t, q∈k; The expected level E(S t ) as the level state S of the active power at the load end at time t+1 t+1 , respectively according to the level state S t and grade status S t+1 Generate a random number ε from a uniform distribution t and ε t+1 , and ε t , ε t+1 ∈[0,1],ε t Independent of ε t+1 ; By formula: Calculate the expected value p of the active power at the load end at time t+1 t+1 .

4. A port terminal shore power box control method according to claim 1, characterized in that: When the active power at the load end is in a stable changing state, the operating strategy of the terminal shore power system is determined according to the following principles: If SOC min ≤SOC t ≤SOC max , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t <SOC min , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 .

5. A port terminal shore power box control method according to claim 1, characterized in that: When the active power at the load end exceeds the threshold value, the operation strategy of the terminal shore power system is determined according to the following principles: When p t+1 >p t hour: If SOC min ≤SOC t ≤SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 ; If SOC t <SOC min , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 ; When p t+1 ≤p t hour: If SOC min ≤SOC t ≤SOC max , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t <SOC min , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 .

6. A port terminal shore power box control method according to claim 2, characterized in that: R t The calculation formula is: Where M represents the total number of battery clusters connected in parallel in the energy storage system; m It is represented as the operating reliability of the mth battery cluster connected in parallel in the energy storage system.

7. A port terminal shore power box control method according to claim 2, characterized in that: SOH t The calculation formula is: In the formula, s tq It is represented as the qth performance index evaluation value of the energy storage system at time t; s qmax It is expressed as the optimal sampling value of the qth performance indicator within the time length λ; s qmin It is expressed as the worst sampled value of the qth performance indicator within the time length λ.

8. A port terminal shore power box control method according to claim 7, characterized in that: The performance index includes at least one of internal resistance, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed.

9. A port terminal shore power box control system, characterized in that: It includes historical data acquisition module, model building module, power change state classification module, energy storage system state evaluation module, real-time data acquisition module, energy storage system working condition evaluation module, and shore power system operation strategy formulation module; The historical data acquisition module is used to obtain the historical data sequence Ω of the active power of the load end of the terminal shore power system, and according to the design capacity P of the terminal shore power system s The load-side active power is equally divided into k levels, and the step-wise intervals of the load-side active power correspond to the load-side active power levels one by one, and the load-side active power state space S = {S1, S2, ..., S k }, where S k It means that the active power at the load end is in the kth level state; The model building module is used to calculate the expected value of the active power at the load end in the next period of time using the Markov chain model. The specific process includes the following steps: Calculate the level state transition probability in the historical data sequence Ω of the active power at the load end, and the calculation formula is: In the formula, It is expressed as the transition probability of the active power level state at the load end from the i-th level state to the j-th level state in one step; It is expressed as the frequency of the active power level state of the load end in the sequence Ω being transferred from the i-th level state to the j-th level state through one step; S i→j It is expressed as the active power at the load end is transferred from the i-th level state to the j-th level state in one step, i, j∈k; Construct the level state transition probability matrix based on the obtained level state transition probability Get the active power p of the load at the current time t t , determine the current load end active power p t Grade status S t , calculate the expected level of active power at the load end at time t+1 according to the constructed level state transition probability matrix E(S t ), the calculation formula is: Among them, t, q∈k; The expected level E(S t ) as the level state S of the active power at the load end at time t+1 t+1 , respectively according to the level state S t and grade status S t+1 Generate a random number ε from a uniform distribution t and ε t+1 , and ε t , ε t+1 ∈[0,1],ε t Independent of ε t+1 ; By formula: Calculate the expected value p of the active power at the load end at time t+1 t+1 ; The power change state classification module is used to construct a load-end active power monitoring model with a time length of λ according to the acquired expected value, and classify the load-end active power change state into a steady change and an over-threshold change using the monitoring model; wherein the expression of the monitoring model is: In the formula, f(p t+r ) is the load end active power change judgment function, and when f(p t )=0, it is determined that the active power at the load end is in a stable changing state; when f(p t )=1, it is determined that the active power at the load end is in an over-threshold change state; η is a constant coefficient greater than 1; Δp k is the reasonable threshold value of active power change; p t is the active power at the load end at the current time t; p t+r is the active power at the load end at the time t+r; The energy storage system status evaluation module is used to obtain the performance index parameters of the energy storage system of the terminal shore power system at the current time t, and according to the formula: Calculate the evaluation value of its operating status at the current moment, where As t Represented as the operating status evaluation value of the energy storage system at time t; R t It is expressed as the reliability of the energy storage system at time t; SOH t Represents the health of the energy storage system at time t; is a constant coefficient, and Among them, R t The calculation formula is: Where M represents the total number of battery clusters connected in parallel in the energy storage system; m It is represented as the operating reliability of the mth battery cluster connected in parallel in the energy storage system; SOH t The calculation formula is: In the formula, s tq It is represented as the qth performance index evaluation value of the energy storage system at time t; s qmax It is expressed as the optimal sampling value of the qth performance indicator within the time length λ; s qmin It is represented as the worst sampled value of the qth performance indicator within the time length λ; and the performance indicator includes at least one of internal resistance, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed; The real-time data acquisition module is used to collect the state of charge (SOC) of the energy storage system at the current time t in real time. t ; The energy storage system operating status evaluation module is used to evaluate the lower limit value As according to the set operating status min With As t The operating condition of the energy storage system is evaluated by the quantitative relationship of the energy storage system. The evaluation principle is: If As t ≥As min , then the energy storage system participates in the regulation process of active power at the load end; If As t <As min , then the energy storage system does not participate in the regulation process of active power at the load end; The shore power system operation strategy formulation module is used to determine the operation strategy of the terminal shore power system according to the determination result of the active power change state of the load end and the operating condition state of the energy storage system; wherein, the determination principle of the operation strategy of the terminal shore power system is: When the energy storage system can participate in the load-side active power regulation process: When the active power at the load end is in a stable changing state: If SOC min ≤SOC t ≤SOC max , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t <SOC min , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 ; When the active power at the load end is in an over-threshold change state, and when p t+1 >p t hour: If SOC min ≤SOC t ≤SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 ; If SOC t <SOC min , the energy storage system is in an idle state, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system and the grid jointly bear the active power p at the load end at time t+1. t+1 ; When the active power at the load end is in an over-threshold change state, and when p t+1 ≤p t hour: If SOC min ≤SOC t ≤SOC max , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t <SOC min , the energy storage system is charged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 ; If SOC t >SOC max , the energy storage system is discharged, and the energy storage system does not participate in bearing the active power p at the load end at time t+1 t+1 .

10. A port terminal shore power box control system according to claim 9, characterized in that: The system further comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor can implement the steps of the method according to any one of claims 1 to 8 when executing the program.

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