An electrified railway co-phase traction power supply system and control method thereof

Abstract

The present invention discloses a co-phase traction power supply system for electrified railways and a control method thereof. The co-phase traction power supply system includes a traction transformer, a compensating matching transformer, a co-phase compensation device, an energy storage device, and a measurement and control device. The primary side of the traction transformer is connected to the three-phase high-voltage bus, and any two terminals of its secondary side are connected to the traction load; the primary side of the compensating matching transformer is connected to the secondary side of the traction transformer; the AC end of the co-phase compensation device is connected to the secondary side of the compensating matching transformer; the energy storage device is connected to the DC end of the co-phase compensation device; and the measurement and control device is connected to the co-phase compensation device and the energy storage device, respectively. Therefore, the present invention can not only realize co-phase power supply for the entire railway line and eliminate electrical phase separation, but also effectively realize the technical and economic optimization of co-phase power supply for electrified railways, thereby solving the power quality problem caused by the load of electric locomotives on electrified railways, which is mainly caused by the negative sequence of the three-phase system.

Description

Technical Field

[0001] The present invention relates to the field of AC electrified railway power supply, and in particular to an electrified railway co-phase traction power supply system and a control method thereof. Background Art

[0002] my country's electrified railways generally use single-phase AC power. To ensure the best possible balance of the single-phase traction load within the three-phase power system, electrified railways often employ a phase-splitting and zone-splitting power supply scheme with alternating phase sequences. Adjacent power supply sections at the zone-splitting point form phase-splitting insulators, known as phase splitting or phase splitting. To prevent arcing when a live electric locomotive passes through the phase split, potentially damaging overhead catenary components and even causing phase-to-phase short circuits, automatic phase splitting technologies are implemented as train speeds increase, preventing the driver from manually resetting, shutting down the auxiliary generators, opening the main circuit breaker, and allowing the train to coast through the neutral section, then closing the main circuit breaker, closing the auxiliary generators, and resetting the traction power level. These technologies primarily include automatic phase splitting with ground switches, automatic onboard phase splitting, and automatic pole-mounted phase splitting. However, transient electrical processes still occur when the train passes through the phase split during switching, which can easily generate significant operational overvoltages or overcurrents, potentially causing damage to the traction network and onboard equipment, impacting power supply reliability and safe train operation. Therefore, the electrical phase separation link is the weakest link in the entire traction power supply system, and excessive phase separation of trains has become a bottleneck in the traction power supply of high-speed railways and even the entire electrified railway.

[0003] Theory and practice have shown that the use of co-phase power supply technology can not only eliminate the phase separation at the traction substation outlet and eliminate the power supply bottleneck, but also effectively control the negative sequence current and achieve the power quality requirements based on the three-phase voltage imbalance (negative sequence) limit, which is conducive to promoting the harmonious development of electricity and railways.

[0004] Obviously, the best choice for achieving same-phase power supply for new railways is to use the simplest and most economical single-phase traction transformer in the traction transformer connection method of the traction substation as the basis, and to equip it with an appropriate amount of same-phase (symmetrical) compensation devices when necessary, so as to cancel the electrical phase separation at the traction substation outlet to eliminate the power supply bottleneck, control the negative sequence to meet the power quality requirements of the three-phase voltage imbalance (negative sequence) limit, and achieve the best match between the traction substation connection method and the power supply device capacity.

[0005] Electrified railways are major industrial users, and their traction loads experience significant fluctuations. Power quality issues, primarily voltage imbalance caused by negative sequence noise, are particularly prominent. GB / T15543-2008, Power Quality Three-Phase Unbalance, defines standards for peak loads and 95% probability maximums. Economically, peak loads are linked to two components of the electricity price: the main traction transformer capacity charge and the maximum demand charge. Energy storage's peak-shaving advantages bring direct economic benefits to users while also managing negative sequence noise and reducing harmonics. Peak shaving achieves economic benefits by reducing maximum demand or directly reducing the capacity of the main traction transformer, thereby reducing fixed capacity charges. Summary of the Invention

[0006] The purpose of the present invention is to provide an electrified railway co-phase traction power supply system and a control method thereof, which can not only realize co-phase power supply for the entire railway line and eliminate electrical phase separation, but also effectively achieve technical and economic optimization of co-phase power supply for electrified railways. At the same time, it can solve the power quality problems caused by the load of electric locomotives on electrified railways, which are mainly caused by the negative sequence of the three-phase system.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] An electrified railway co-phase traction power supply system, the co-phase traction power supply system comprising:

[0009] A traction transformer is used to transform the line voltage of the three-phase high-voltage busbar to the traction busbar. The primary side of the traction transformer is connected to the three-phase high-voltage busbar, and any two terminals of the secondary side are connected to the traction load.

[0010] A compensating matching transformer is used for energy conversion of a three-phase traction transformer, wherein the primary side of the compensating matching transformer is connected to the secondary side of the traction transformer;

[0011] A co-phase compensation device, used for power quality compensation of the co-phase traction power supply system, wherein the AC end of the co-phase compensation device is connected to the secondary side of the compensation matching transformer;

[0012] An energy storage device, used for storing electrical energy and controlling charging and discharging, the energy storage device being connected to the DC terminal of the in-phase compensation device;

[0013] The measurement and control device is used to detect the positive and negative active power and size, voltage and current size on the traction bus and coordinate the real-time charging and discharging of the energy storage device and the power quality compensation of the in-phase compensation device. The measurement and control device is connected to the in-phase compensation device and the energy storage device respectively.

[0014] Preferably, the energy storage device includes a first energy storage converter, a second energy storage converter, ... and an nth energy storage converter and a first energy storage medium, a second energy storage medium, ... and an nth energy storage medium; one end of the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter is respectively connected to the DC end of the in-phase compensation device, and the other end of the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter is respectively connected to the corresponding first energy storage medium, the second energy storage medium, ... and the nth energy storage medium.

[0015] Further preferably, the measurement and control device includes a coordination control unit, a voltage transformer and a current transformer, the input end of the coordination control unit is respectively connected to the voltage transformer, the current transformer, the first energy storage medium, the second energy storage medium,... and the nth energy storage medium, and the output end of the coordination control unit is respectively connected to the first compensation unit, the second compensation unit,... and the nth compensation unit and the first energy storage converter, the second energy storage converter,... and the nth energy storage converter.

[0016] Preferably, the in-phase compensation device includes a first compensation unit, a second compensation unit, ... and an nth compensation unit, the first compensation unit, the second compensation unit, ... and the nth compensation unit are connected in parallel with each other, and the DC end of each compensation unit is respectively connected to the corresponding first energy storage converter, second energy storage converter, ... and nth energy storage converter.

[0017] Preferably, it also includes a spare traction transformer for transmitting the line voltage of the three-phase high-voltage bus to the traction bus, the primary side of the spare traction transformer is connected to the three-phase high-voltage bus, and any two terminals of the secondary side are connected to the traction load.

[0018] More preferably, the secondary side of the traction transformer is connected to the primary side of the compensating matching transformer through a first circuit breaker; the secondary side of the standby traction transformer is connected to the primary side of the compensating matching transformer through a second circuit breaker.

[0019] In order to solve the above technical problems, another technical solution adopted by the present invention is as follows:

[0020] A control method for an electrified railway co-phase traction power supply system as described in the above technical solution is characterized in that the specific steps of the control method include charging and discharging of an energy storage device and power quality compensation of a co-phase compensation device, wherein the specific steps of the control method for power quality compensation of the co-phase compensation device are:

[0021] Detect the voltage value of the voltage transformer and the current value of the current transformer on the traction bus, and calculate the active power P on the traction bus using the instantaneous power theory. s and reactive power Qs ;

[0022] According to the instantaneous power theory and the condition of full compensation, that is, the same-phase compensation device fully compensates the negative sequence current component and the positive sequence current reactive component, and the power supply only provides the active power of the traction load and the energy storage device, the active power P at the three-phase high-voltage busbar inlet can be obtained. HB =P L +P se and reactive power Q HB =0, and then the total current of the secondary side of the traction transformer can be obtained; according to Kirchhoff's current law, the total current that needs to be compensated by the in-phase compensation device can be obtained;

[0023] According to the instantaneous power theory, the total current to be compensated is converted into the negative-sequence current and positive-sequence reactive current required to be compensated by the same-phase compensation device, and the negative-sequence current and positive-sequence reactive current required to be compensated by the same-phase compensation device are divided into n current instructions according to the number of compensation units in the same-phase compensation device, and are transmitted to the first compensation unit, the second compensation unit, ... and the nth compensation unit.

[0024] Preferably, when the current instructions received by the first compensation unit, the second compensation unit, ... and the nth compensation unit are greater than the current corresponding to the maximum capacity of the first compensation unit, the second compensation unit, ... and the nth compensation unit, they operate according to their respective maximum capacities.

[0025] Preferably, the specific steps of the charge and discharge control method of the energy storage device are:

[0026] The measurement and control device collects the active power P on the traction bus s The positive and negative and size of the first energy storage medium, the second energy storage medium, ... and the SOC energy state of the nth energy storage medium, let P c_max is the maximum charging power of the energy storage device, P d_max is the maximum discharge power of the energy storage device;

[0027] According to the active power P on the traction bus s The positive and negative values and the energy states SOC of the first energy storage medium, the second energy storage medium, ... and the nth energy storage medium are used to determine the active power P of the traction bus. s and the critical reference value P of traction condition ref , Maximum charging power P of energy storage device c_max and the maximum discharge power P of the energy storage device d_max The relationship between the three is that the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter respectively control the discharge or charge of the corresponding first energy storage medium, the second energy storage medium, ... and the nth energy storage medium;

[0028] The charging or discharging power is evenly distributed according to the number of energy storage converters and transmitted to the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter.

[0029] More preferably, when P s >P ref +P d_max When the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter control the first energy storage medium, the second energy storage medium, ... and the nth energy storage medium of the same-phase traction power supply system to discharge to the traction bus, wherein the discharge power is P d_max , until the energy state SOC=0;

[0030] When P ref <P s ≤P ref +P d_max When the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter control the first energy storage medium, the second energy storage medium, ... and the nth energy storage medium of the same-phase traction power supply system to discharge to the traction bus, wherein the discharge power is P s -P ref , until the energy state SOC=0;

[0031] When P ref -P c_max ≤P s <P ref When SOC is less than 100%, the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter control the same-phase traction power supply system to charge the first energy storage medium, the second energy storage medium, ... and the nth energy storage medium, and the charging power is P ref -P s , until the energy state SOC=100%;

[0032] When P s <P ref -P c_max When SOC is less than 100%, the first energy storage converter, the second energy storage converter, ... and the nth energy storage converter control the same-phase traction power supply system to charge the first energy storage medium, the second energy storage medium, ... and the nth energy storage medium, and the charging power is P c_max , until the energy state SOC = 100%.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] First, in the system described in the present invention, the in-phase compensation device only generates a negative sequence component, which can control the negative sequence of the power grid to meet the three-phase voltage imbalance without changing the active power flow of the traction substation traction network;

[0035] Second, the system of the present invention proposes a novel combination consisting primarily of a traction transformer, a compensating matching transformer, and a co-phase compensation device, which improves the operational flexibility of the traction substation. When the co-phase compensation device is out of operation, the traction transformer can operate independently for a short period of time without affecting normal line operation, and the electrical phase separation link at the traction substation outlet can be eliminated.

[0036] 3. The present invention can add a compensation matching transformer and a co-phase compensation device to an existing single-phase power supply traction substation, which has a simple structure, excellent performance and is easy to implement.

[0037] 4. In the system of the present invention, the same-phase compensation devices can be operated in parallel according to capacity, thereby facilitating expansion of the compensation capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of the electrified railway co-phase traction power supply system described in Example 1 of the present invention.

[0039] Figure 2 It is a structural diagram of the relationship between the coordinated control unit, the in-phase compensation device and the energy storage device described in Example 1 of the present invention.

[0040] Figure 3 It is a structural diagram of the electrified railway co-phase traction power supply system described in the second embodiment of the present invention.

[0041] Figure 4 This is a basic flow chart of the control method of the electrified railway co-phase traction power supply system described in the third embodiment of the present invention.

[0042] Figure 5 It is a specific flow chart of the power quality compensation control method of the in-phase compensation device described in Example 3 of the present invention.

[0043] Figure 6 It is a specific flow chart of the charge and discharge control method of the energy storage device described in the third embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to better understand the invention, the invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0045] The present invention operates as follows: The traction transformer TT and the backup traction transformer TB transmit the line voltage of the three-phase power system to the traction bus OCS. The compensating matching transformer TMT is connected to the three-phase circuit, and the secondary voltage level is coordinated with the in-phase compensator NC. The in-phase compensator NC consists of multiple compensation units, whose AC port is connected to the secondary side of the compensating matching transformer TMT and whose DC port is connected to the energy storage device ED, which consists of multiple energy storage converters and multiple energy storage media. The traction transformer TT, the compensating matching transformer TMT, its in-phase compensator NC, and the energy storage device ED together supply power to the traction bus OCS. The capacity of the in-phase compensator NC is determined by the power of the traction load that causes the three-phase voltage imbalance to exceed the limit specified in national standards. The capacity of the traction transformer TT and the backup traction transformer TB is determined by the traction load power, after deducting the capacity of the in-phase compensator NC, and according to their own overload capacity. The capacity of the compensating matching transformer TMT is determined by its own capacity utilization rate, overload capacity, and the capacity of the in-phase compensator NC.

[0046] Example 1

[0047] like Figure 1 As shown, an embodiment of the present invention provides a co-phase traction power supply system for an electrified railway, wherein the co-phase traction power supply system includes a traction transformer TT for transmitting the line voltage of a three-phase high-voltage bus to a traction bus OCS, a compensation matching transformer TMT for energy conversion of the traction transformer TT, a co-phase compensation device NC for power quality compensation of the co-phase traction power supply system, an energy storage device ED for storing electrical energy and controlling charging and discharging, and a measurement and control device MC for detecting the positive and negative active power and magnitude, voltage and current magnitude, and coordinating the real-time charging and discharging of the energy storage device ED and power quality compensation of the co-phase compensation device NC on the traction bus OCS. The primary side of the traction transformer TT is connected to the three-phase high-voltage bus, and any two terminals of its secondary side are connected to the traction load; the primary side of the compensation matching transformer TMT is connected to the secondary side of the traction transformer TT; the AC end of the co-phase compensation device NC is connected to the secondary side of the compensation matching transformer TMT; the energy storage device ED is connected to the DC end of the co-phase compensation device NC; and the measurement and control device MC is connected to the co-phase compensation device NC and the energy storage device ED, respectively. The secondary side of the traction transformer TT is connected to the primary side of the compensation matching transformer TMT via a first circuit breaker KT1. The power quality compensation described in the embodiment of the present invention is compensation for negative sequence, reactive power and harmonics.

[0048] The energy storage device ED includes a first energy storage converter PCS1, a second energy storage converter PCS2, ... and an nth energy storage converter PCS n and the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E nThe first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n One end of each of the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n The other end is connected to the corresponding first energy storage medium E1, second energy storage medium E2, ... and nth energy storage medium E n connect.

[0049] The in-phase compensation device NC includes a first compensation unit AD1, a second compensation unit AD2, ... and an nth compensation unit AD n , the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n The DC terminals of each compensation unit are connected in parallel with the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n The same-phase compensation devices NC in the same-phase traction power supply system according to the embodiment of the present invention can be operated in parallel according to capacity, thereby facilitating expansion of the compensation capacity.

[0050] like Figure 2 As shown, the measurement and control device MC includes a coordination control unit CC, a voltage transformer PT and a current transformer CT. The input end of the coordination control unit CC is respectively connected to the voltage transformer PT, the current transformer CT, the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E n The output end of the coordination control unit CC is connected to the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n and the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n In an embodiment of the present invention, the compensation unit is specifically a three-phase converter.

[0051] Under normal circumstances, the traction transformer TT, the compensating matching transformer TMT, the co-phase compensator NC, and the energy storage device ED all operate normally. If the compensating matching transformer TMT, the co-phase compensator NC, or the energy storage device RD are deactivated, the traction transformer can temporarily operate independently without affecting normal line operation, and the electrical phase separation at the traction substation outlet can be eliminated. Therefore, the co-phase traction power supply system described in this embodiment of the present invention can be added to an existing single-phase traction substation by adding a compensating matching transformer and a co-phase compensator. It features a simple structure, superior performance, and ease of implementation.

[0052] The co-phase traction power supply system described in the embodiment of the present invention proposes a new combination mainly composed of a traction transformer, a compensation matching transformer and a co-phase compensation device, which improves the flexibility of the operation of the traction substation; and the co-phase compensation device only generates a negative sequence component, which can control the negative sequence of the power grid to meet the three-phase voltage imbalance without changing the active power flow of the traction network of the traction substation.

[0053] Example 2

[0054] like Figure 3 As shown, this embodiment of the present invention provides a co-phase traction power supply system for an electrified railway. The main difference from the first embodiment of the present invention is that this co-phase traction power supply system also includes a standby traction transformer TB for transmitting the line voltage of the three-phase high-voltage bus to the traction bus. The primary side of the standby traction transformer TB is connected to the three-phase high-voltage bus, and any two terminals of its secondary side are connected to the traction load. The secondary side of the standby traction transformer TB is connected to the primary side of the compensating matching transformer TMT through a second circuit breaker KT2. Other technical features are exactly the same as those of the first embodiment of the present invention and are not repeated here.

[0055] Under normal circumstances, the traction transformer TT, the compensating matching transformer TMT, the co-phase compensator NC, and the energy storage device ED are all operational, while the standby traction transformer TB is inoperative. When the traction transformer TT is deactivated, the standby traction transformer TB takes over. When the compensating matching transformer TMT, the co-phase compensator NC, and the energy storage device RD are deactivated, the traction transformer TT can operate independently, with the standby traction transformer TB also replacing it. Therefore, embodiments of the present invention enhance the safety and reliability of the electrified railway co-phase traction power supply system.

[0056] Example 3

[0057] like Figure 4 and Figure 5 As shown, an embodiment of the present invention provides a control method for an electrified railway co-phase traction power supply system, wherein the specific steps of the control method include charging and discharging of an energy storage device ED and power quality compensation of a co-phase compensation device NC. The specific steps of the control method for power quality compensation of the co-phase compensation device NC are as follows:

[0058] Detect the voltage value of the voltage transformer PT and the current value of the current transformer CT on the traction bus OCS, and calculate the active power P on the traction bus OCS using the instantaneous power theory. s and reactive power Q s ;

[0059] According to the instantaneous power theory and the condition of full compensation, that is, the same-phase compensation device NC fully compensates the negative sequence current component and the positive sequence current reactive component, and the power supply only provides the active power of the traction load and the energy storage device, the active power P at the three-phase high-voltage busbar inlet can be obtained. HB =P L +P se and reactive power Q HB = 0, and then the total current of the secondary side of the traction transformer TT can be obtained; according to Kirchhoff's current law, the total current that the in-phase compensation device NC needs to compensate can be obtained; where P se is the charging and discharging power of the energy storage converter, which is positive during charging and negative during discharging.

[0060] According to the instantaneous power theory, the total current to be compensated is converted into the negative sequence current and positive sequence reactive current to be compensated by the same-phase compensation device NC. The negative sequence current and positive sequence reactive current to be compensated by the same-phase compensation device NC are divided into n current instructions according to the number of compensation units in the same-phase compensation device NC, and are transmitted to the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n .

[0061] When the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n The received current instruction is greater than the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n When the maximum capacity corresponds to the current, the first compensation unit AD1, the second compensation unit AD2, ... and the nth compensation unit AD n operating at their respective maximum capacities.

[0062] like Figure 6 As shown, the specific steps of the charge and discharge control method of the energy storage device are as follows: the measurement and control device MC collects the active power P on the traction bus OCS s The positive and negative and size of the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E n Energy state SOC, let P c_max is the maximum charging power of the energy storage device, P d_max is the maximum discharge power of the energy storage device; according to the active power P on the traction bus OCS s The positive and negative values of the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E n The energy state SOC is used to determine the active power P on the traction bus OCS. s and the critical reference value P of traction condition ref , Maximum charging power P of energy storage device c_max and the maximum discharge power P of the energy storage deviced_max The relationship between the three is as follows: the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n The first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E1 are controlled respectively. n Discharging or charging; dividing the charging or discharging power according to the number of energy storage converters and transmitting it to the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n .

[0063] When P s >P ref +P d_max When the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n Control the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E1 of the same-phase traction power supply system n Discharge to the traction bus OCS, where the discharge power is P d_max , until the energy state SOC=0; when P ref <P s ≤P ref +P d_max When the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n Control the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E1 of the same-phase traction power supply system n Discharge to the traction bus OCS, where the discharge power is P s -P ref , until the energy state SOC=0; when P ref -P c_max ≤P s <P ref When SOC<100%, the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS n Control the same-phase traction power supply system to charge the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E n , the charging power is P ref -P s , until the energy state SOC=100%; when P s <P ref -P c_max When SOC<100%, the first energy storage converter PCS1, the second energy storage converter PCS2, ... and the nth energy storage converter PCS nControl the same-phase traction power supply system to charge the first energy storage medium E1, the second energy storage medium E2, ... and the nth energy storage medium E n , the charging power is P c_max , until the energy state SOC = 100%.

[0064] The control method for the co-phase traction power supply system described in the embodiment of the present invention improves the operational flexibility of the traction substation by controlling a novel combination consisting of a traction transformer, a compensating matching transformer, and a co-phase compensation device. Moreover, the co-phase compensation device only generates a negative-sequence component, which can control the negative sequence of the power grid to meet the three-phase voltage imbalance without changing the active power flow of the traction substation traction network. At the same time, it also effectively achieves the technical and economic optimization of the co-phase power supply of electrified railways and solves the power quality problems caused by the load of electric locomotives on electrified railways, which are mainly caused by the negative sequence of the three-phase system.

Claims

1. An electrified railway co-phase traction power supply system, characterized in that: The co-phase traction power supply system comprises: Traction transformer (TT), used to transform the line voltage of the three-phase high-voltage busbar to the traction busbar (OCS). The primary side of the traction transformer (TT) is connected to the three-phase high-voltage busbar, and any two terminals of the secondary side are connected to the traction load; a compensating matching transformer (TMT), configured to convert energy of a traction transformer (TT), wherein the primary side of the compensating matching transformer (TMT) is connected to the secondary side of the traction transformer (TT); A co-phase compensator (NC) is used for power quality compensation of the co-phase traction power supply system, wherein the AC end of the co-phase compensator (NC) is connected to the secondary side of the compensation matching transformer (TMT); an energy storage device (ED) for storing electrical energy and controlling charging and discharging, the energy storage device (ED) being connected to a DC terminal of the in-phase compensation device (NC); a measurement and control device (MC) for detecting the positive and negative active power and magnitude, voltage and current magnitude, and coordinating the real-time charging and discharging of the energy storage device (ED) and the power quality compensation of the in-phase compensation device (NC) on the traction bus (OCS); the measurement and control device (MC) is connected to the in-phase compensation device (NC) and the energy storage device (ED) respectively; The energy storage device (ED) includes a first energy storage converter (PCS1), a second energy storage converter (PCS2), ... and an nth energy storage converter (PCS n ) and the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ); the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) are connected to the DC end of the in-phase compensation device (NC), the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) are connected to the corresponding first energy storage medium (E1), second energy storage medium (E2), ... and nth energy storage medium (E n )connect; The measurement and control device (MC) collects the positive and negative and magnitude of the active power Ps on the traction bus (OCS) and combines the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n )’s energy state SOC, let P c_max is the maximum charging power of the energy storage device, P d_max is the maximum discharge power of the energy storage device; According to the active power P on the traction bus (OCS) s The positive and negative values of the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) to determine the active power P on the traction bus (OCS) s and the critical reference value P of traction condition ref , Maximum charging power P of energy storage device c_max and the maximum discharge power P of the energy storage device d_max The relationship between the three is as follows: the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) respectively control the corresponding first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) discharge or charge; The charging or discharging power is evenly distributed according to the number of energy storage converters and transmitted to the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ).

2. The electrified railway co-phase traction power supply system according to claim 1, characterized in that: The in-phase compensation device (NC) comprises a first compensation unit (AD1), a second compensation unit (AD2), ... and an nth compensation unit (AD n ), the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ) are connected in parallel with each other, and the DC end of each compensation unit is respectively connected to the corresponding first energy storage converter (PCS1), second energy storage converter (PCS2), ... and nth energy storage converter (PCS n )connect.

3. The electrified railway co-phase traction power supply system according to claim 2, characterized in that: The measurement and control device (MC) comprises a coordination control unit (CC), a voltage transformer (PT) and a current transformer (CT), wherein the input end of the coordination control unit (CC) is respectively connected to the voltage transformer (PT), the current transformer (CT), the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ), the output end of the coordination control unit (CC) is respectively connected to the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ) and the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n )connect.

4. The electrified railway co-phase traction power supply system according to claim 1, characterized in that: It also includes a standby traction transformer (TB) for transmitting the line voltage of the three-phase high-voltage bus to the traction bus. The primary side of the standby traction transformer (TB) is connected to the three-phase high-voltage bus, and any two terminals of the secondary side are connected to the traction load.

5. The electrified railway co-phase traction power supply system according to claim 4, characterized in that: The secondary side of the traction transformer (TT) is connected to the primary side of the compensating matching transformer (TMT) through a first circuit breaker (KT1); the secondary side of the standby traction transformer (TB) is connected to the primary side of the compensating matching transformer (TMT) through a second circuit breaker (KT2).

6. A control method for an electrified railway co-phase traction power supply system according to any one of claims 1 to 5, characterized in that: The specific steps of the control method include charging and discharging of the energy storage device and power quality compensation of the in-phase compensation device, wherein the specific steps of the control method for power quality compensation of the in-phase compensation device are: Detect the voltage value of the voltage transformer (PT) and the current value of the current transformer (CT) on the traction bus (OCS), and calculate the active power P on the traction bus (OCS) through the instantaneous power theory. s and reactive power Q s ; According to the instantaneous power theory and the condition of full compensation, that is, the same-phase compensator (NC) fully compensates the negative sequence current component and the positive sequence current reactive component, and the power supply only provides the active power of the traction load and the energy storage device (ED), the active power P at the three-phase high-voltage busbar inlet can be obtained. HB =P L +P se and reactive power Q HB = 0, and then the total current of the secondary side of the traction transformer (TT) can be obtained; according to Kirchhoff's current law, the total current that needs to be compensated by the common-phase compensator (NC) can be obtained; According to the instantaneous power theory, the total current to be compensated is converted into the negative sequence current and positive sequence reactive current required to be compensated by the same-phase compensation device (NC), and the negative sequence current and positive sequence reactive current required to be compensated by the same-phase compensation device (NC) are divided into the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD3) according to the number of compensation units in the same-phase compensation device (NC). n ) and transmits the current instruction to the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ).

7. The control method of the electrified railway co-phase traction power supply system according to claim 6, characterized in that: When the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ) receives a current instruction greater than the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ) corresponds to the current, the first compensation unit (AD1), the second compensation unit (AD2), ... and the nth compensation unit (AD n ) are operated at their respective maximum capacities.

8. The control method of the electrified railway co-phase traction power supply system according to claim 6, characterized in that: The specific steps of the charge and discharge control method of the energy storage device are: The measurement and control device (MC) collects the positive and negative and magnitude of the active power Ps on the traction bus (OCS) and combines the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n )’s energy state SOC, let P c_max is the maximum charging power of the energy storage device, P d_max is the maximum discharge power of the energy storage device; According to the active power P on the traction bus (OCS) s The positive and negative values of the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) to determine the active power P on the traction bus (OCS) s and the critical reference value P of traction condition ref , Maximum charging power P of energy storage device c_max and the maximum discharge power P of the energy storage device d_max The relationship between the three is as follows: the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) respectively control the corresponding first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) discharge or charge; The charging or discharging power is evenly distributed according to the number of energy storage converters and transmitted to the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ).

9. The control method of the electrified railway co-phase traction power supply system according to claim 8, characterized in that: When P s >P ref +P d_max When the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) controls the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) is discharged to the traction bus (OCS), where the discharge power is P d_max , until the energy state SOC=0; When P ref <P s ≤P ref +P d_max When the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) controls the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ) is discharged to the traction bus (OCS), where the discharge power is P s -P ref , until the energy state SOC=0; When P ref -P c_max ≤P s <P ref When SOC<100%, the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) controls the same-phase traction power supply system to charge the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ), the charging power is P ref -P s , until the energy state SOC=100%; When P s <P ref -P c_max When SOC<100%, the first energy storage converter (PCS1), the second energy storage converter (PCS2), ... and the nth energy storage converter (PCS n ) controls the same-phase traction power supply system to charge the first energy storage medium (E1), the second energy storage medium (E2), ... and the nth energy storage medium (E n ), the charging power is P c_max , until the energy state SOC = 100%.

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