Port wharf shore connection box control system and control method thereof

Abstract

The invention discloses a port wharf shore connection box control system and a control method thereof, and relates to the technical field of shore connection box control. A historical data sequence of active power of a load end of a wharf shore power system is acquired, an active power state space of the load end is constructed, an expected value of the active power of the load end in a next time period is calculated by using a Markov chain model, and a load end active power monitoring model with a time length of lambda is constructed according to the acquired expected value. And classifying the active power change state of the load end into stable change and over-threshold change by using the monitoring model, obtaining performance index parameters of the energy storage system of the wharf shore power system at the current t moment, calculating an operation state evaluation value of the energy storage system at the current moment, and determining the operation condition state of the energy storage system. The charge state of the energy storage system at the current t moment is collected in real time, and the operation strategy of the wharf shore power system is determined according to the judgment result of the active power change state of the load end and the operation working condition state of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of shore power box control, and in particular to a port terminal shore power box control system and a control method thereof. Background Art

[0002] The shore power box is a special ship power connection device for the port terminal, which provides a fast and safe standard shore power interface for the berthed ships, and realizes the ship's cable power supply, data collection, billing and settlement. The port energy conservation and emission reduction policy has promoted the development of the port ship shore-based power supply system. The use of shore power by ships is an effective way to reduce emissions during the period when the ship is at port. It can reduce emissions of sulfur oxides, nitrogen oxides, particulate matter, etc., and reduce noise pollution. Generally, during the design stage of the terminal shore power system, the selection of its system capacity needs to be determined based on multiple factors such as berth type, number of berths, maximum berthed ships and ship equipment power demand, and introduces a simultaneous coefficient parameter, which represents the number of ships docked at the port berth at the same time, to estimate the capacity of the terminal shore power system.

[0003] However, due to the randomness of the departure and arrival times of ships in the port, and the large differences in the power demand of each berthed ship, which is determined by the tonnage and type of the ship, the ship load power changes greatly during the grid connection and disconnection process, causing power quality problems such as voltage fluctuations on the grid side, which not only increases the power loss of the grid and brings severe challenges to the grid, but also the strong fluctuation of load power can easily cause a series of problems such as false start-up of protection equipment such as relay protection and excessive temperature of transformer winding leads, reducing the reliability of shore power system operation. To this end, we propose a port terminal shore power box control system and a control method thereof. Summary of the invention

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

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A port terminal shore power box control method, comprising:

[0007] 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 The active power at the load end is expressed as the kth level state. The expected value of the active power at the load end in the next period is calculated using the Markov chain model. The acquisition process includes the following steps:

[0008] According to the design capacity P of the terminal shore power system sThe 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};

[0009] 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;

[0010] Construct the level state transition probability matrix based on the obtained level state transition probability

[0011] 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;

[0012] 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 ;

[0013] By formula: Calculate the expected value p of the active power at the load end at time t+1 t+1 ;

[0014] 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;

[0015] 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;

[0016] The expression of the monitoring model is:

[0017]

[0018] 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.

[0019] The method further comprises the following steps:

[0020] 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 R t The calculation formula is:

[0021]

[0022] 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.

[0023] SOH t The calculation formula is:

[0024]

[0025] In the formula, s tqIt 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, wherein the performance indicator includes at least one of internal resistance, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed;

[0026] 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:

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

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

[0029] Among them, the principles for determining the operation strategy of the terminal shore power system are:

[0030] When the energy storage system can participate in the load-side active power regulation process:

[0031] When the active power at the load end is in a stable changing state:

[0032] 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 ;

[0033] 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 ;

[0034] 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 ;

[0035] When the active power at the load end is in an over-threshold change state, and when p t+1 >p t hour:

[0036] 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 ;

[0037] 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 ;

[0038] 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 ;

[0039] When the active power at the load end is in an over-threshold change state, and when p t+1 ≤p t hour:

[0040] 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 ;

[0041] 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 ;

[0042] 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 .

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

[0044] 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 sThe 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. The load-side active power state space S = {S1, S2, ..., S k};

[0045] 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;

[0046] 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;

[0047] 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 calculate its operating status evaluation value at the current time;

[0048] 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 ;

[0049] 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 status of the energy storage system is evaluated by the quantitative relationship of

[0050] 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 at the load end and the operating condition state of the energy storage system;

[0051] The system also 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 of the load end of the dock shore power system, constructs the active power state space of the load end, uses the Markov chain model to calculate the expected value of the active power of the load end in the next period, and constructs a load end active power monitoring model with a time length of λ according to the obtained expected value. The monitoring model is used to classify the change state of the active power at the load end into a steady change and an over-threshold change, obtains the performance index parameters of the energy storage system of the dock shore power system at the current time t, calculates its operating state evaluation value at the current time, determines its operating condition state, and collects the charge state of the energy storage system at the current time t in real time. According to the judgment result of the load end active power change state and the operating condition state of the energy storage system, the operation strategy of the dock shore power system is determined, which can reduce the influence of the large change of the ship load power during the grid connection and disconnection process on the grid side voltage and enhance the reliability of the shore power system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a flow chart of a port terminal shore power box control system and a control method thereof according to the present invention;

[0055] Figure 2 The present invention is a structural block diagram of a port terminal shore power box control system. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with specific implementation methods, wherein the accompanying drawings are only used for exemplary descriptions and represent only schematic diagrams rather than actual drawings, and should not be understood as limiting the present invention. In order to better illustrate the specific implementation methods of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size 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 terminal shore power system, and calculate 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 constructing 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;

[0059] Step 2: Use the Markov chain model to calculate the expected value of the active power at the load end in the next period. The acquisition process includes the following steps:

[0060] Step 21: 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;

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

[0062] Step 23: Obtain the active power p at the load end 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;

[0063] Step 24: Calculate 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 ;

[0064] Step 25: By formula: Calculate the expected value p of the active power at the load end at time t+1 t+1 ;

[0065] Step 3: Based on the expected value obtained, a load-side active power monitoring model with a time length of λ is constructed, and the load-side active power change state is classified into two types: steady change and over-threshold change using the monitoring model; wherein, the expression of the monitoring model is:

[0066]

[0067] 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;

[0068] Step 4: Evaluate the operating status of the energy storage system of the terminal shore power system; the specific process includes:

[0069] Step 41: 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 R t The calculation formula is:

[0070]

[0071] 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.

[0072] SOH t The calculation formula is:

[0073]

[0074] 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 by the worst sampled value of the qth performance indicator within the time length λ, and the performance indicator includes at least one of the internal resistance, operating temperature, power density, charging efficiency, discharging efficiency, cycle efficiency, and grid response speed;

[0075] Step 42: Set the lower limit of the energy storage system operation status assessment As min , according to As min With As tThe quantitative relationship determines the operating state of the energy storage system, and the determination principle is:

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

[0077] If As t <As min , it means that the energy storage system is in poor operating condition and cannot participate in the load end active power regulation process.

[0078] Step 5: Real-time acquisition of the state of charge (SOC) of the energy storage system at the current time t 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, the operation strategy of the terminal shore power system is determined; among which, the determination principle of the operation strategy of the terminal shore power system is:

[0079] When the energy storage system can participate in the load-side active power regulation process:

[0080] When the active power at the load end is in a stable changing 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 time t+1 t+1 ;

[0082] 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 ;

[0083] 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 ;

[0084] When the active power at the load end is in an over-threshold change state, and when p t+1 >p t hour:

[0085] 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 ;

[0086] 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 ;

[0087] 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 ;

[0088] When the active power at the load end is in an over-threshold change state, and when p t+1 ≤p t hour:

[0089] 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 ;

[0090] 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 ;

[0091] 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 .

[0092] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached 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 It is expressed as the health status 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 , 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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