A real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles

Abstract

The present invention discloses a real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles. The method comprises the following steps: obtaining the real-time operating status of the flexible hub traction substation; determining the active reference power of the back-to-back converter, energy storage system, energy feed system, and charging system in the current operating mode; determining the reactive reference power used by the back-to-back converter for negative sequence and reactive power management of the traction power supply system, and the reactive reference power used by the energy feed system for power factor compensation of the distribution system; and controlling the back-to-back converter using a converter active and reactive power decoupling control algorithm based on the active and reactive reference powers. The method can coordinate the back-to-back converter, energy storage system, energy feed system, and charging system in real time to achieve optimal utilization of regenerative braking energy and photovoltaic energy in the flexible hub traction substation, improve the power quality of the traction power supply system and distribution system, and enable efficient operation of the flexible hub traction substation.

Description

Technical Field

[0001] The present invention relates to the field of traction power supply systems, and in particular to a real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics and electric vehicles. Background Art

[0002] With the rapid development of electrified railways, it has become a global consensus that building a low-carbon, energy-efficient, and grid-friendly railway power supply system will contribute to environmentally friendly transportation and power energy systems. Flexible traction substations, integrating power electronic converters, energy storage systems, and renewable energy sources, are considered an effective solution to achieve this goal. They provide renewable power to reduce carbon emissions, an energy buffer to recover regenerative braking energy, and the potential for flexible power flow scheduling to improve energy efficiency and power quality. Thanks to these advantages, flexible traction substations offer a comprehensive and superior solution for the sustainable and efficient operation of railway power supply systems. The operational performance of flexible traction substations depends on the system architecture and power control under complex dynamic operating conditions. Efficient real-time power control methods are crucial for optimizing the utilization of regenerative braking energy and photovoltaic energy in flexible hub traction substations, and for improving the power quality of the traction power supply and distribution systems. Summary of the Invention

[0003] The purpose of the present invention is to provide a real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics and electric vehicles.

[0004] The technical solutions for achieving the purpose of the present invention are as follows:

[0005] A real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles, the flexible hub traction substation comprising: an α power supply arm and a β power supply arm connected to a three-phase power grid via a traction transformer, two AC ends of a back-to-back converter connected to the α power supply arm and the β power supply arm, respectively; a distribution system busbar connected to a railway distribution network via a first grid-connected transformer, and a distribution system load connected to the distribution system busbar via a distribution transformer; and an energy feed system comprising a bidirectional DC / AC converter and a second grid-connected transformer, the DC end of the bidirectional DC / AC converter connected to the DC end of the back-to-back converter, and the AC end of the bidirectional DC / AC converter connected to the DC end of the back-to-back converter via the second grid-connected transformer. The invention also includes a grid transformer connected to a distribution system bus; an energy storage system, which includes a bidirectional DC / DC converter and an energy storage medium, and the energy storage medium is connected to the DC end of the back-to-back converter through the bidirectional DC / DC converter; a photovoltaic system, which includes an isolation transformer, an AC / DC converter and a photovoltaic unit, and the distribution system bus is connected to the photovoltaic unit in sequence through the isolation transformer and the AC / DC converter; a charging system, which includes an isolation transformer and an AC / DC converter, and the distribution system bus is connected to the AC / DC converter through the isolation transformer; the DC end of the AC / DC converter is connected to the electric vehicle; and a real-time power control method, which includes:

[0006] Step 1: Obtain the real-time operating status of the flexible hub traction substation, including the total power of the traction power supply system and the total power of the distribution system; the total power of the traction power supply system is the sum of the real-time load active power of the α power supply arm and the β power supply arm, and the total power of the distribution system is the sum of the real-time load active power of the distribution system and the real-time power generation power of the photovoltaic system;

[0007] Step 2: Determine the current operating mode of the flexible hub traction substation:

[0008] If the total power of the traction power supply system and the total power of the distribution system are both greater than a power deficit threshold, the flexible hub traction substation is in a power deficit mode; the power deficit threshold is greater than zero;

[0009] If the total power of the traction power supply system and the total power of the distribution system are both less than the excess power threshold, the flexible hub traction substation is in excess power mode; the excess power threshold is less than zero;

[0010] If the total power of the traction power supply system is greater than the power deficit threshold, and the total power of the distribution system is less than the power surplus threshold, the flexible hub traction substation is in the first power complementary mode;

[0011] If the total power of the traction power supply system is less than the power deficit threshold, and the total power of the distribution system is greater than the power surplus threshold, the flexible hub traction substation is in the second power complementary mode;

[0012] Step 3: Determine the active reference power of the back-to-back converter, energy storage system, energy feedback system, and charging system under the current operating mode;

[0013] Step 4: Determine the reactive reference power used by the back-to-back converter for negative sequence and reactive power management of the traction power supply system, and the reactive reference power used by the energy feed system for power factor compensation of the distribution system;

[0014] Step 5: Control the back-to-back converter using a converter active and reactive decoupling control algorithm based on the active reference power of the back-to-back converter, energy storage system, energy feedback system, and charging system, and the reactive reference power of the back-to-back converter and energy feedback system.

[0015] Furthermore, if the current operating mode is the power deficit mode, step 3 is specifically as follows:

[0016] Determine the active reference power P of the energy storage system ESS :

[0017]

[0018] P Gt (t)+P ESS (t)≥0(2)

[0019]

[0020] E ESS (t) = P ESS (t)Δt+E ESS (t-1) (4)

[0021]

[0022] Determine the active reference power P of the energy feedback system EFS , active reference power P of the charging system EV , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t):

[0023]

[0024] P EV (t)+P EFS (t)≥0(8)

[0025]

[0026] E EV (t) = P EV (t)Δt+E EV (t-1) (11)

[0027]

[0028] P EFS (t)≤P Gt (t)+P ESS (t)(14)

[0029] -P Gd (t)≤P EV (t)≤P Gd (t)+P Gt (t)+P ESS (t)(15)

[0030]

[0031] Furthermore, if the current operating mode is the overpower mode, step 3 is specifically as follows:

[0032] Determine the active reference power P of the energy storage system ESS :

[0033]

[0034] P Gt (t)+P ESS (t)≤0(21)

[0035] P EV (t)+P EFS (t)≤0(22)

[0036]

[0037] E ESS (t) = P ESS (t)Δt+E ESS (t-1) (4)

[0038]

[0039] Determine the active reference power P of the energy feedback system EFS , active reference power P of the charging system EV , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t):

[0040]

[0041] P Gt (t)+P ESS (t)≤P EFS (t) (24)

[0042] P EV (t)≤-[P Gd (t)-P Gt (t)-P ESS (t)] (25)

[0043]

[0044] E EV (t) = P EV (t)Δt+E EV (t-1) (11)

[0045]

[0046] Furthermore, if the current operating mode is the first power complementary mode, step 3 is specifically as follows:

[0047] Determine the active reference power P of the energy feedback system EFS and the active reference power P of the charging system EV :

[0048]

[0049] -min[-P Gd (t),P Gt (t)]≤P EFS (t)≤min[-P Gd (t),P Gt (t)] (27)

[0050]

[0051] E EV (t) = P EV (t)Δt+E EV (t-1) (11)

[0052]

[0053]

[0054] Determine the active reference power P of the energy storage system ESS , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t):

[0055]

[0056] P Gt (t)-P EFS (t)≤P ESS(t)(30)

[0057]

[0058] E ESS (t) = P ESS (t)Δt+E ESS (t-1) (4)

[0059]

[0060] Furthermore, if the current operating mode is the second power complementary mode, step 3 is specifically as follows:

[0061] Determine the active reference power P of the energy feedback system EFS and the active reference power P of the charging system EV :

[0062]

[0063] E EV (t) = P EV (t)Δt+E EV (t-1) (11)

[0064]

[0065] Determine the active reference power P of the energy storage system ESS , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t):

[0066]

[0067] P ESS (t)≤-[P Gt (t)-P EFS (t)] (34)

[0068]

[0069] E ESS (t) = P ESS (t)Δt+E ESS (t-1) (4)

[0070]

[0071] In the above technical solution, P Gt (t) is the total power of the traction power supply system, P Gd (t) is the total power of the distribution system, P ESS (t) is the real-time active power of the energy storage system, EESS (t) is the real-time energy of the energy storage medium; is the rated active power of the energy storage system, is the rated energy of the energy storage medium; SoC ESS (t) is the real-time charge state of the energy storage system, are the lower limit and upper limit of the charge state of the energy storage medium respectively; P EV (t), E EV (t) are the real-time active power and energy of electric vehicles, They are the rated active power, rated energy, and SoC of electric vehicles. EV (t) is the real-time state of charge of the electric vehicle, They are the lower limit and upper limit of the state of charge of electric vehicles; P EFS (t), are the real-time active power and rated capacity of the energy feedback system respectively; P Lα (t), P Lβ (t) are the real-time load active power of α and β power supply arms respectively; is the rated capacity of the back-to-back converter.

[0072] Furthermore, the step 4 is specifically as follows:

[0073]

[0074]

[0075] Q EFS (t) = -Q Ld (t) (38)

[0076]

[0077] Among them, Q cα (t), Q cβ (t) are the reactive reference powers of the α and β power supply arms of the back-to-back converter, Q Lα (t), Q Lβ (t) are the real-time reactive power of the loads of the α and β power supply arms respectively; Q EFS (t) is the reactive reference power of the energy-feed system, Q Ld (t) is the real-time load reactive power of the distribution system.

[0078] The beneficial effect of the present invention is that it can coordinate back-to-back converters, energy storage systems, energy feedback systems and charging systems in real time to achieve optimal utilization of regenerative braking energy and photovoltaic energy in the flexible hub traction substation, and improve the power quality of the traction power supply system and distribution system, so that the flexible hub traction substation can operate efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 Schematic diagram of the architecture of a flexible hub traction substation for access to energy storage, photovoltaics, and electric vehicles.

[0080] Figure 2 Flowchart of the real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles. DETAILED DESCRIPTION

[0081] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0082] like Figure 1 As shown in the figure, a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles includes a traction power supply system, a 10kV distribution system, a back-to-back converter, an energy storage system, an energy feedback system, and a control system. The traction power supply system includes traction transformers T1 and T2, an AT power supply line B1, and a direct supply line B2. The two ends of the primary side of T1 are connected to phases A and B of the three-phase grid, and the two ends of the secondary side are connected to the contact wire T of the α power supply arm. α and positive feeder F α , the middle end of the secondary side is connected to the ground; the two ends of the primary side of T2 are connected to the C phase and B phase of the three-phase grid respectively, and the two ends of the secondary side are connected to the contact wire T of the β power supply arm respectively. β and positive feeder F β , the middle end of the secondary side is connected to the ground; the contact wire T of the AT power supply line B1 α , positive feeder F α , contact line T β , positive feeder F β and rail R are connected to the contact line T of the secondary side of T1 α , positive feeder F α , contact line T of T2-order side β , positive feeder F β to the earth; the 10kV distribution system includes distribution transformer T6, photovoltaic system D1, charging system D2 and distribution load D3; the three terminals of the primary side of T6 are connected to phase A, phase B and phase C of the three-phase grid respectively, and the three terminals of the secondary side are connected to the distribution system bus T d ; Photovoltaic system D1 includes isolation transformer T7, AC / DC converter C5 and photovoltaic unit S2; T7 primary side is connected to the distribution system bus T d , the secondary side is connected to the AC end of C5; the DC end of C5 is connected to S2; the charging system D2 includes an isolation transformer T8, an AC / DC converter C6 and an electric vehicle S3; the primary side of T8 is connected to the distribution system bus T d , the secondary side is connected to the AC end of C6; the DC end of C6 is connected to S3; the distribution load D3 includes the isolation transformer T9 and the railway distribution system load S4; the primary side of T9 is connected to the distribution system bus Td , the secondary side is connected to S4; the back-to-back converter includes isolation transformers T3 and T4 and four-quadrant converters C1 and C2; the input end of T3 is connected to the α power supply arm, and the output end is connected to the AC side of C1; the input end of T4 is connected to the β power supply arm, and the output end is connected to the AC side of C2; the energy storage system includes a bidirectional DC / DC converter C3 and an energy storage medium S1; one end of C3 is connected to the DC side of C1 and C2, and the other end is connected to S1; the energy feedback system includes a bidirectional DC / AC converter C4 and a grid-connected transformer T5; the DC end of C4 is connected to the DC side of C1 and C2, and the AC end is connected to one end of T5; the other end of T5 is connected to the distribution system bus T d ; The control system is connected to the back-to-back converter, energy storage system, energy feedback system and charging system respectively.

[0083] like Figure 2 As shown, the above-mentioned real-time power control method of the flexible hub traction substation includes:

[0084] Step 1. Obtain the real-time operating status and initialization parameters of the flexible hub traction substation, including: the real-time load active power P of the two power supply arms of the traction substation Lα (t) and P Lβ (t), reactive power Q Lα (t) and Q Lβ (t), real-time load active power P of 10kV distribution system Ld (t), reactive power Q Ld (t), real-time state of charge SoC of energy storage system ESS (t), photovoltaic real-time power generation power P PV (t), real-time state of charge SoC of electric vehicles EV (t).

[0085] Step 2. According to the real-time operating status of the deflexible hub traction substation obtained in step 1, its operating mode is determined. Specifically, the total power P of the traction power supply system is determined. Gt (t) = P Lα (t)+P Lβ (t) and the total power of the 10kV distribution system P Gd (t) = P PV (t)+P Ld (t) and the power thresholds of different operating modes; if the total power of the traction power supply system is positive (i.e., P Gt (t)>P DPM , P DPM >0 is the power deficit threshold) and the total power of the 10kV distribution system is positive (P Gd (t)>P DPM), at this time, the regenerative braking energy of the traction power supply system and the photovoltaic power generation power of the 10kV distribution system are less than their respective load power requirements, and the flexible hub traction substation is in power deficit mode; if the total power of the traction power supply system is negative (i.e., P Gt (t) <P SPM , P SPM <0 is the power excess threshold) and the total power of the 10kV distribution system is negative (P Gd (t) <P SPM ), at this time, the regenerative braking energy of the traction power supply system and the photovoltaic power generation power of the 10kV distribution system are greater than their respective load power requirements, and the flexible hub traction substation is in power surplus mode; if the total power of the traction power supply system is positive (i.e., P Gt (t)>P DPM ) and the total power of the 10kV distribution system is negative (P Gd (t) <P SPM ) or the total power of the traction power supply system is negative (i.e. P Gt (t) <P SPM ) and the total power of the 10kV distribution system is positive (P Gd (t)>P DPM ), at this time, the total power of the traction power supply system is in opposite direction to the total power of the 10kV distribution system, and the flexible hub traction substation is in power complementary mode.

[0086] Step 3. Based on the real-time operating mode of the flexible hub traction substation determined in step 2, calculate the active reference power of the back-to-back converter, energy storage system, energy feedback system, and charging system under different operating modes.

[0087] 3.1 If the flexible hub traction substation is in power deficit mode, the active reference power of the energy storage system, energy feedback system and charging system is achieved through two-stage optimization.

[0088] In the first stage, the active reference power of the energy storage system is solved by establishing an objective function including the active power of the energy storage system, the energy feedback system, and the charging system, as well as the corresponding operating constraints. Specifically,

[0089]

[0090] P Gt (t)+P ESS (t)≥0(2)

[0091]

[0092] E ESS (t) = P ESS (t)Δt+E ESS (t-1) (4)

[0093]

[0094] Where, P ESS and E ESS are the real-time active power and energy of the energy storage medium respectively; and is the rated active power and rated energy of the energy storage medium; and are the lower and upper limits of the state of charge of the energy storage medium, respectively.

[0095] In the second stage, the objective function including the active power of the energy feed system and the charging system is established, and the corresponding operating constraints are used to solve the active reference power of the energy feed system and the charging system. Based on the active reference power of the energy feed system and the charging system and the operating principle of the back-to-back converter, the active reference power of the back-to-back converter (i.e., the active reference power P of the α and β power supply arm ports of the back-to-back converter) is calculated. cα (t), P cβ (t)), specifically:

[0096]

[0097] P EV (t)+P EFS (t)≥0(8)

[0098]

[0099] E EV (t) = P EV (t)Δt+E EV (t-1) (11)

[0100]

[0101] P EFS (t)≤P Gt (t)+P ESS (t)(14)

[0102] -P Gd (t)≤P EV (t)≤P Gd (t)+P Gt (t)+P ESS (t)(15)

[0103]

[0104] Where, P EV and E EV are the real-time active power and energy of the electric vehicle, respectively; and are the rated active power and rated energy of the electric vehicle respectively; and are the lower and upper limits of the state of charge of the electric vehicle respectively; P EFS and are the real-time active power and rated capacity of the energy feed system respectively; P cα and P cβ are the active reference powers of the α and β power supply arm ports of the back-to-back converter respectively; is the rated capacity of the back-to-back converter.

[0105] 3.2 If the flexible hub traction substation is in power surplus mode, the active reference power of the energy storage system, energy feed system, and charging system is optimized through a two-stage process. The objective functions of the first and second stages are the inverse of the corresponding objective functions in power deficit mode. The active reference power of the back-to-back converters is calculated in the same manner as in power deficit mode.

[0106] In the first stage, the active reference power of the energy storage system is obtained by solving equations (20)-(22) and equations (3)-(6).

[0107] Formulas (20)-(22) are as follows:

[0108]

[0109] P Gt (t)+P ESS (t)≤0 (21)

[0110] P EV (t)+P EFS (t)≤0 (22)

[0111] In the second stage, the active reference power of the energy feedback system, charging system and back-to-back converter is obtained by solving equations (23)-(25), (9) and (10)-(19).

[0112] Formulas (23)-(25) are as follows:

[0113]

[0114] P Gt (t)+P ESS (t)≤P EFS (t) (24)

[0115] P EV (t)≤-[P Gd (t)-P Gt (t)-P ESS (t)] (25)3.3 If the flexible hub traction substation is in the power complementary mode of working condition 1 (i.e. PGt (t)>P DPM And P Gd (t) <P SPM ), the active reference power of the back-to-back converter, energy storage system, energy feed system, and charging system is optimized through a two-stage process. The objective function of the first stage is the same as that of the second stage in the power surplus mode, and the objective function of the second stage is the same as that of the first stage in the power deficit mode.

[0116] In the first stage, the active reference power of the energy feedback system and the charging system is obtained by solving equations (26)-(28), (9) and (10)-(13).

[0117] Formulas (26)-(28) are as follows:

[0118]

[0119] -min[-P Gd (t),P Gt (t)]≤P EFS (t)≤min[-P Gd (t),P Gt (t)] (27)

[0120]

[0121] In the second stage, the active reference power of the energy storage system and the back-to-back converter is obtained by solving Equations (29)-(30), (3)-(6), and (16)-(19).

[0122] Formulas (29)-(30) are as follows:

[0123]

[0124] P Gt (t)-P EFS (t)≤P ESS (t) (30)3.4 If the flexible hub traction substation is in the power complementary mode of working condition 2 (i.e. P Gt (t) <P SPM And P Gd (t)>P DPM ), the active reference power of the back-to-back converter, energy storage system, energy feed system, and charging system is optimized through a two-stage process. The objective function of the first stage is the same as that of the second stage in the power deficit mode, and the objective function of the second stage is the same as that of the first stage in the power surplus mode.

[0125] In the first stage, the active reference power of the energy feedback system and the charging system is obtained by solving equations (31)-(32), (9) and (10)-(13).

[0126] Formulas (31) and (32) are as follows:

[0127]

[0128] -min[P Gd (t),-P Gt (t)]≤P EFS (t)≤min[P Gd (t),-P Gt (t)] (32)

[0129] In the second stage, the active reference power of the energy storage system and the back-to-back converter is obtained by solving Equations (33)-(34), (3)-(6), and (16)-(19).

[0130] Formulas (33)-(34) are as follows:

[0131]

[0132] P ESS (t)≤-[P Gt (t)-P EFS (t)] (34)

[0133] Step 4. Based on the active reference power and respective remaining capacity of the back-to-back converter and the energy feed system calculated in step 3, the reactive reference power of the back-to-back converter for negative sequence and reactive power management of the traction power supply system and the reactive reference power of the energy feed system for power factor compensation of the 10 kV distribution system are calculated respectively by using equations (35)-(37) and (38)-(39).

[0134]

[0135] Q EFS (t) = -Q Ld (t) (38)

[0136]

[0137] Where Q cα and Q cβ are the reactive reference powers of the α and β power supply arms of the back-to-back converter respectively; Q EFS is the reactive reference power of the energy feedback system.

[0138] Step 5. Based on the active and reactive reference powers of the energy storage system, energy feedback system, charging system, and back-to-back converter calculated in steps 3 and 4, execute the converter control algorithm (converter active and reactive power decoupling control algorithm) to achieve active and reactive power control.

Claims

1. A real-time power control method for a flexible hub traction substation connected to energy storage, photovoltaics, and electric vehicles, the flexible hub traction substation comprising: The α power supply arm and the β power supply arm are connected to the three-phase power grid through a traction transformer, and the two AC ends of the back-to-back converter are connected to the α power supply arm and the β power supply arm respectively; The distribution system bus is connected to the railway distribution network through a first grid-connected transformer, and the distribution system load is connected to the distribution system bus through the distribution transformer; it also includes an energy feed system, which includes a bidirectional DC / AC converter and a second grid-connected transformer, the DC end of the bidirectional DC / AC converter is connected to the DC end of the back-to-back converter, and the AC end of the bidirectional DC / AC converter is connected to the distribution system bus through the second grid-connected transformer; it also includes an energy storage system, which includes a bidirectional DC / DC converter and an energy storage medium, and the energy storage medium is connected to the DC end of the back-to-back converter through the bidirectional DC / DC converter; it also includes a photovoltaic system, which includes an isolation transformer, an AC / DC converter and a photovoltaic unit, and the distribution system bus is connected to the photovoltaic unit in sequence through the isolation transformer and the AC / DC converter; it also includes a charging system, which includes an isolation transformer and an AC / DC converter, and the distribution system bus is connected to the AC / DC converter through the isolation transformer; the DC end of the AC / DC converter is connected to the electric vehicle; The invention is characterized by comprising: Step 1: Obtain the real-time operating status of the flexible hub traction substation, including the total power of the traction power supply system and the total power of the distribution system; the total power of the traction power supply system is the sum of the real-time load active power of the α power supply arm and the β power supply arm, and the total power of the distribution system is the sum of the real-time load active power of the distribution system and the real-time power generation power of the photovoltaic system; Step 2: Determine the current operating mode of the flexible hub traction substation: If the total power of the traction power supply system and the total power of the distribution system are both greater than a power deficit threshold, the flexible hub traction substation is in a power deficit mode; the power deficit threshold is greater than zero; If the total power of the traction power supply system and the total power of the distribution system are both less than the excess power threshold, the flexible hub traction substation is in excess power mode; the excess power threshold is less than zero; If the total power of the traction power supply system is greater than the power deficit threshold, and the total power of the distribution system is less than the power surplus threshold, the flexible hub traction substation is in the first power complementary mode; If the total power of the traction power supply system is less than the power deficit threshold, and the total power of the distribution system is greater than the power surplus threshold, the flexible hub traction substation is in the second power complementary mode; Step 3: Determine the active reference power of the back-to-back converter, energy storage system, energy feedback system, and charging system under the current operating mode; Step 4: Determine the reactive reference power used by the back-to-back converter for negative sequence and reactive power management of the traction power supply system, and the reactive reference power used by the energy feed system for power factor compensation of the distribution system; Step 5: Control the back-to-back converter using a converter active and reactive decoupling control algorithm based on the active reference power of the back-to-back converter, energy storage system, energy feedback system, and charging system, and the reactive reference power of the back-to-back converter and energy feedback system.

2. The control method according to claim 1, wherein: If the current operating mode is the power deficit mode, then step 3 is specifically as follows: Determine the active reference power P of the energy storage system ESS : P Gt (t)+P ESS (t)≥0(2) E ESS (t)=P ESS (t)Δt+E ESS (t-1) (4) Determine the active reference power P of the energy feedback system EFS , active reference power P of the charging system EV , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t): P EV (t)+P EFS (t)≥0(8) E EV (t)=P EV (t)Δt+E EV (t-1) (11) P EFS (t)≤P Gt (t)+P ESS (t)(14)-P Gd (t)≤P EV (t)≤P Gd (t)+P Gt (t)+P ESS (t)(15) Among them, P Gt (t) is the total power of the traction power supply system, P Gd (t) is the total power of the distribution system, P ESS (t) is the real-time active power of the energy storage system, E ESS (t) is the real-time energy of the energy storage medium; is the rated active power of the energy storage system, is the rated energy of the energy storage medium; SoC ESS (t) is the real-time charge state of the energy storage system, are the lower limit and upper limit of the charge state of the energy storage medium respectively; P EV (t), E EV (t) are the real-time active power and energy of electric vehicles, They are the rated active power, rated energy, and SoC of electric vehicles. EV (t) is the real-time state of charge of the electric vehicle, They are the lower and upper limits of the state of charge of electric vehicles respectively; are the real-time active power and rated capacity of the energy feedback system respectively; P Lα (t), P Lβ (t) are the real-time load active power of α and β power supply arms respectively; is the rated capacity of the back-to-back converter.

3. The control method according to claim 1, wherein: If the current operating mode is the overpower mode, then step 3 is specifically as follows: Determine the active reference power P of the energy storage system ESS : P Gt (t)+P ESS (t)≤0 (21)P EV (t)+P EFS (t)≤0 (22) E ESS (t)=P ESS (t)Δt+E ESS (t-1) (4) Determine the active reference power P of the energy feedback system EFS , active reference power P of the charging system EV , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t): P Gt (t)+P ESS (t)≤P EFS (t) (24) P EV (t)≤-[P Gd (t)-P Gt (t)-P ESS (t)] (25) E EV (t)=P EV (t)Δt+E EV (t-1) (11) Among them, P Gt (t) is the total power of the traction power supply system, P Gd (t) is the total power of the distribution system, P ESS (t) is the real-time active power of the energy storage system, E ESS (t) is the real-time energy of the energy storage medium; is the rated active power of the energy storage system, is the rated energy of the energy storage medium; SoC ESS (t) is the real-time charge state of the energy storage system, are the lower limit and upper limit of the charge state of the energy storage medium respectively; P EV (t), E EV (t) are the real-time active power and energy of electric vehicles, They are the rated active power, rated energy, and SoC of electric vehicles respectively. EV (t) is the real-time state of charge of the electric vehicle, They are the lower limit and upper limit of the state of charge of electric vehicles; P EFS (t), are the real-time active power and rated capacity of the energy feedback system respectively; P Lα (t), P Lβ (t) are the real-time load active power of α and β power supply arms respectively; is the rated capacity of the back-to-back converter.

4. The control method according to claim 1, wherein: If the current operating mode is the first power complementary mode, then step 3 is specifically as follows: Determine the active reference power P of the energy feedback system EFS and the active reference power P of the charging system EV : -min[-P Gd (t),P Gt (t)]≤P EFS (t)≤min[-P Gd (t),P Gt (t)] (27) E EV (t)=P EV (t)Δt+E EV (t-1) (11) Determine the active reference power P of the energy storage system ESS , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t): P Gt (t)-P EFS (t)≤P ESS (t)(30) E ESS (t)=P ESS (t)Δt+E ESS (t-1) (4) Among them, P Gt (t) is the total power of the traction power supply system, P Gd (t) is the total power of the distribution system, P ESS (t) is the real-time active power of the energy storage system, E ESS (t) is the real-time energy of the energy storage medium; is the rated active power of the energy storage system, is the rated energy of the energy storage medium; SoC ESS (t) is the real-time charge state of the energy storage system, are the lower limit and upper limit of the charge state of the energy storage medium respectively; P EV (t), E EV (t) are the real-time active power and energy of electric vehicles, They are the rated active power, rated energy, and SoC of electric vehicles. EV (t) is the real-time state of charge of the electric vehicle, They are the lower limit and upper limit of the state of charge of electric vehicles; P EFS (t), are the real-time active power and rated capacity of the energy feedback system respectively; P Lα (t), P Lβ (t) are the real-time load active power of α and β power supply arms respectively; is the rated capacity of the back-to-back converter.

5. The control method according to claim 1, wherein: If the current operating mode is the second power complementary mode, then step 3 is specifically as follows: Determine the active reference power P of the energy feedback system EFS and the active reference power P of the charging system EV : -min[P Gd (t),-P Gt (t)]≤P EFS (t)≤min[P Gd (t),-P Gt (t)] (32) E EV (t)=P EV (t)Δt+E EV (t-1) (11) Determine the active reference power P of the energy storage system ESS , and the active reference power P of the α and β power supply arms of the back-to-back converter cα (t), P cβ (t): P ESS (t)≤-[P Gt (t)-P EFS (t)] (34) E ESS (t)=P ESS (t)Δt+E ESS (t-1) (4) Among them, P Gt (t) is the total power of the traction power supply system, P Gd (t) is the total power of the distribution system, P ESS (t) is the real-time active power of the energy storage system, E ESS (t) is the real-time energy of the energy storage medium; is the rated active power of the energy storage system, is the rated energy of the energy storage medium; SoC ESS (t) is the real-time charge state of the energy storage system, are the lower limit and upper limit of the charge state of the energy storage medium respectively; P EV (t), E EV (t) are the real-time active power and energy of electric vehicles, They are the rated active power, rated energy, and SoC of electric vehicles. EV (t) is the real-time state of charge of the electric vehicle, They are the lower and upper limits of the state of charge of electric vehicles respectively; are the real-time active power and rated capacity of the energy feedback system respectively; P Lα (t), P Lβ (t) are the real-time load active power of α and β power supply arms respectively; is the rated capacity of the back-to-back converter.

6. The control method according to any one of claims 2 to 5, characterized in that: The step 4 is specifically as follows: Q EFS (t)=-Q Ld (t) (38) Among them, Q cα (t), Q cβ (t) are the reactive reference powers of the α and β power supply arms of the back-to-back converter, Q Lα (t), Q Lβ (t) are the real-time reactive power of the loads of the α and β power supply arms respectively; Q EFS (t) is the reactive reference power of the energy-feed system, Q Ld (t) is the real-time load reactive power of the distribution system.

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