Energy storage cophase power supply system based on V-connection traction transformer, control method and storage medium

Abstract

The invention discloses an energy storage cophase power supply system based on a V-connection traction transformer, a control method and a storage medium, and belongs to the technical field of electrified railway power supply. The energy storage in-phase power supply system comprises a V-connection traction transformer, three single-phase compensation devices, an energy storage device and a coordination control device. The primary side of the V-connection traction transformer is connected with a three-phase power supply, and any port of the secondary side is connected with a traction load; aC ends of the three single-phase compensation devices are respectively connected to different ports of the secondary side, and DC ends are connected in parallel to a DC bus; the energy storage device is also connected in parallel with the DC bus. The coordination control device collects current and voltage signals and controls operation of the devices. The system has the functions of energy storage and in-phase power supply, and solves the problems of large traction load fluctuation of a traditional electrified railway traction substation, power return caused by train regenerative braking, train over-electricity split-phase stall and electric energy quality management.

Description

Technical Field

[0001] The present invention relates to the technical field of electrified railway power supply, and in particular to an energy storage co-phase power supply system based on a V-connected traction transformer, a control method for an energy storage co-phase power supply system based on a V-connected traction transformer, and a computer-readable storage medium. Background Art

[0002] my country's electrified railways use industrial frequency single-phase AC traction power supply. In recent years, with the development of high-speed railways and heavy-load railways and the promotion and application of AC, DC and AC trains, the power of a single train has also increased dramatically. On the one hand, the single-phase and mobile traction loads generated by high-power trains cause the traction power supply system to affect the power quality of the power system, mainly three-phase imbalance. On the other hand, AC, DC and AC trains mainly use regenerative braking during deceleration braking to convert the kinetic energy of the train into electrical energy. Although this is beneficial to energy saving and consumption reduction, it also leads to drastic fluctuations in the train load power and even returns power to the power system, which not only pushes up the operating costs of the traction power supply system, but also affects the safe and stable operation of the power system. In addition, there is electrical phase separation in the traction power supply system, which leads to discontinuous power supply to the train, affecting the train's running speed. The opening and closing of switches during the train's phase separation process causes electrical transients and other problems, affecting the safe and reliable operation of the train.

[0003] In order to improve the impact of electrified railways on the power quality of the public power grid, solutions such as reactive compensation devices, active filters, and railway power conditioners can be used. However, due to the limitations of the traction power supply mode and system structure, the above solutions can solve the power quality problem well, but cannot eliminate the electrical phase separation of the contact network. The vast majority of trains in my country are also equipped with automatic over-phase devices, which can automatically control the opening and closing of switches to allow trains to pass through electrical phase separation, but they still cannot eliminate the electrical transient problems caused by the opening and closing of switches, nor can they solve the power quality problem. The researchers of this team proposed a co-phase power supply system, which uses passive compensation technology or active compensation technology to form a co-phase power supply system. It can comprehensively manage power quality problems such as negative sequence, reactive power, and harmonics, and at the same time eliminate the electrical phase separation of the contact network. It is considered to be a relatively ideal power supply solution for electrified railways.

[0004] In recent years, energy storage has developed rapidly as an important component of smart grids and systems with a high proportion of renewable energy power generation. The installed capacity of energy storage systems has increased significantly, which has effectively smoothed the volatility of renewable energy power generation. It has played an important role in peak load shaving, power support and flexible control of the power system, and the construction of a "clean, low-carbon, safe and efficient" energy industry system. How to combine power quality control, cancellation of contact network phase separation and energy storage to construct a new type of energy storage co-phase power supply system is a topic worth exploring. Summary of the invention

[0005] The purpose of the present invention is to provide an energy storage co-phase power supply system, control method and storage medium based on a V-connected traction transformer, which has the functions of energy storage and co-phase power supply, and solves the problems of large traction load fluctuation, train regenerative braking energy utilization, train over-current phase stall and power quality management in traditional electrified railway traction substations.

[0006] In order to solve the technical problem, the present invention adopts the following technical solution: An energy storage co-phase power supply system based on a V-connected traction transformer, the energy storage co-phase power supply system comprising: The V-connected traction transformer TT is used to transform the external power supply on the primary side to the traction bus on the secondary side. The primary side of the V-connected traction transformer TT is connected to the three-phase power system PS. The three terminals of the secondary side of the V-connected traction transformer TT are connected to the first traction bus BB one by one. T1 , the second traction bus BB T2 and grounding electrode GD, on the first traction bus BB T1 A traction load TL is connected between the grounding electrode GD; A single-phase compensation device for charging and discharging power conversion and power quality compensation, comprising a first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 ; Energy storage device ES, used for charging and discharging power conversion and energy storage or release, the positive electrode of the energy storage device ES is connected to the first DC bus BB D1 , the negative pole is connected to the second DC bus BB D2 ; The coordination control device CS is used to detect the operating parameters of the traction load and the energy storage device ES, and control the operation of the single-phase compensation device and the energy storage device ES to achieve charging and discharging power conversion and power quality compensation; the input end of the coordination control device CS is connected to the following signals: The traction load feeder is composed of the first traction bus BB T1 The current transformer LH connected in series L Secondary side signal i L , the first single-phase compensation device CD 1 The AC end is connected to the first traction bus BB T1 The current transformer LH connected in series 1 Secondary side signal i CD1 , the second single-phase compensation device CD 2 The AC end is connected in series with the current transformer LH of the grounding electrode GD. 2 Secondary side signal i CD2 , the third single-phase compensation device CD 3 The AC end is connected to the second traction bus BB T2The current transformer LH connected in series 3 Secondary side signal i CD3 , the energy storage device ES is connected to the first DC bus BB D1 The DC current sensor LH connected in series ES Secondary side signal i ES , and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 , the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 , connected to the first DC bus BB D1 and the second DC bus BB D2 DC voltage sensor YH D Secondary side signal u D ; The bidirectional signal ports of the coordination control device CS are respectively connected to the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 , the third single-phase compensation device CD 3 And the bidirectional signal port of the energy storage device ES is connected.

[0007] Preferably, the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The AC ends of the traction transformers are connected to the three different ports of the secondary side of the V-connected traction transformer TT, and the positive poles of the DC ends are connected in parallel and connected to the first DC bus BB. D1 , the negative poles of their DC terminals are connected in parallel and connected to the second DC bus BB D2 ; The first single-phase compensation device CD 1 The first matching transformer MT is cascaded in sequence. 1 and the first single-phase AC-DC converter AD 1 , the second single-phase compensation device CD 2 The second matching transformer MT is cascaded in sequence. 2 and the second single-phase AC-DC converter AD 2 , the third single-phase compensation device CD 3 The third matching transformer MT is cascaded in sequence. 3 and the third single-phase AC-DC converter AD 3 .

[0008] Preferably, the energy storage device ES comprises a DC-DC converter DD and an energy storage module SM which are cascaded in sequence.

[0009] Preferably, the energy storage co-phase power supply system further comprises a standby V-connected traction transformer TB used as a standby transformer for the V-connected traction transformer TT, the primary side of the standby V-connected traction transformer TB is connected to the three-phase power system PS, and any one port of the secondary side of the standby V-connected traction transformer TB is connected to the traction load TL; the three different ports of the secondary side of the standby V-connected traction transformer TB are also one-to-one corresponding to the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 AC connection.

[0010] A second aspect of the present invention provides a control method for an energy storage co-phase power supply system based on a V-connected traction transformer as described in the above technical solution, wherein the specific steps of the control method include: Step 1: System initialization: The coordination control device CS executes the definition of electrical quantities; Step 2: Calculation of charging and discharging power: The coordination control device CS first calculates the active power and reactive power currently absorbed by the traction load TL, and detects the current state of charge SOC of the energy storage device ES through the bidirectional signal between the coordination control device CS and the energy storage device ES. ES , and then the energy storage device ES and the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The charge and discharge power is determined; Step 3: Power quality compensation power calculation: The coordination control device CS performs the first single-phase compensation device CD according to the charge and discharge power calculation value. 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The power quality compensation power is determined; Step 4: The coordination control device CS performs the energy storage device ES and the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The comprehensive output current is generated and the above devices are controlled to output current respectively. After a preset time step △t, it returns to step 2 and executes in a loop.

[0011] Preferably, the specific method for defining the electrical quantity in step 1 is as follows: Feeder current transformer LH for traction load TL L Secondary side signal i L The polarity is determined by the first traction bus BB T1 The traction load TL flowing into the first traction bus BB is positive. T1Voltage transformer YH T1 Secondary side signal u T1 The polarity is set to the first traction bus BB T1 The corresponding end of is positive, and the corresponding end of the grounding electrode GD is negative. Based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TL L , reactive power Q L and harmonic current i Lh ; Second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The polarity is set to the second traction bus BB T2 The corresponding end of is positive, and the corresponding end of the ground electrode GD is negative; Connected to the first traction bus BB together with the traction load TL T1 The first single-phase compensation device CD 1 The secondary side signal of the AC current transformer is defined as i CD1 , the polarity is determined by the first traction bus BB T1 Flows into the first single-phase compensation device CD 1 Positive, based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the first single-phase compensation device CD 1 AC current transformer secondary side signal i CD1 Calculate the first single-phase compensation device CD 1 Active power P absorbed by the AC end 1 and reactive power Q 1 ; Connected to the second traction bus BB T2 The second single-phase compensation device CD between the grounding electrode GD 2 The secondary side signal of the AC current transformer is defined as i CD2 The polarity is set to flow from the grounding electrode GD into the second single-phase compensation device CD 2 is positive, based on the second single-phase compensation device CD 2 AC current transformer secondary side signal i CD2 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The inverted signal of the second single-phase compensation device CD is calculated 2Active power P absorbed by the AC end 2 and reactive power Q 2 ; Connected to the first traction bus BB T1 and the second traction bus BB T2 The third single-phase compensation device CD between 3 The secondary side signal of the AC current transformer is defined as i CD3 , the polarity is determined to be the same as that of the second traction bus BB T2 Flows into the third single-phase compensation device CD 3 is positive, based on the third single-phase compensation device CD 3 AC current transformer secondary side signal i CD3 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 With the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The difference between the third single-phase compensation device CD is calculated 3 Active power P absorbed by the AC end 3 and reactive power Q 3 ; Energy storage device ES DC end current sensor LH ES Secondary side signal i ES The polarity is set to flow into the first DC bus BB D1 is positive, DC terminal voltage sensor YH D Secondary side signal u D The polarity is set to the first DC bus BB D1 The corresponding end is positive, the second DC bus BB D2 The corresponding end is negative, based on the DC end current sensor LH of the energy storage device ES ES Secondary side signal i ES And DC voltage sensor YH D Secondary side signal u D Calculate the active power P released by the energy storage device ES ES .

[0012] Preferably, the specific method for determining the charge and discharge power in step 2 is as follows: Update the sampling signals of all input terminals of the coordination control device CS, and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TLL , reactive power Q L and harmonic current i Lh ; The historical operation status of the traction load TL is counted to obtain the historical average active power P within the preset time length before the current moment. Lav If there is no historical data of traction load, the historical average active power P Lav The initial value is set to zero, and the average active power of the traction load is counted and calculated after the operation starts; If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC allowed max , where 0 <SOC min <SOC max <1, then charge and discharge control is performed: the target discharge power value of the energy storage device ES is P ES *=P L -P Lav , the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=P Lav / 3-P L , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=P Lav / 3; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , the energy storage device ES power recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=-P RS , where P RS The energy storage device restores power, which is a preset value, and its value is greater than zero and less than the historical average active power P Lav The absolute value of the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=P RS , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=0; If the current state of charge SOC of the energy storage device ES ES Greater than or equal to the upper limit of the state of charge SOC max , the energy storage device overflow recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=P RS , the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=-P RS , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=0.

[0013] Preferably, the specific method for determining the power quality compensation power in step 3 is as follows: Reactive power control: First single-phase compensation device CD 1 The target value of reactive power absorbed by the AC end is Q 1 *Meet the reactive power Q absorbed by the traction load TL L ; Harmonic current control: First single-phase compensation device CD 1 The target value of harmonic current absorbed by the AC end is i 1h *Meet the harmonic current i absorbed by the traction load TL Lh ; Perform negative sequence power control: If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC allowed max , then no negative sequence power control is performed: the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of reactive power absorbed by the AC end is zero; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , or the SOC ES Greater than or equal to the upper limit of the state of charge SOC max , further judgment is needed, and the rules for further judgment are: According to the three-phase power system PS and the preset standard of power quality three-phase voltage unbalance, the single-phase power allowable value of the secondary side of the traction transformer TT connected to V is calculated by S AN Indicates that S AN ≥0, if the data is insufficient and cannot be calculated, the single-phase power allowable value SAN Use the preset value; when the active power P currently absorbed by the traction load TL L The modulus value of |P L |Less than or equal to the single-phase power allowable value S AN , then no negative sequence power control is performed, and the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The reactive power target value absorbed by the AC end is zero; if the module value |P L |Greater than the single-phase power allowable value S AN , then negative sequence power control is performed, and further judgment is made. The rules for further judgment are: If P L >0, the second single-phase compensation device CD 2 The reactive power target value absorbed by the AC end is Q 2 *=(S AN -P L ) / , the third single-phase compensation device CD 3 The reactive power target value absorbed by the AC end is Q 3 *=(P L -S AN ) / If P L <0, the second single-phase compensation device CD 2 The reactive power target value absorbed by the AC end is Q 2 *=-(P L +S AN ) / , the third single-phase compensation device CD 3 The reactive power target value absorbed by the AC end is Q 3 *=(P L +S AN ) / .

[0014] Preferably, the specific method for generating the comprehensive output current in step 4 is as follows: The coordination control device CS detects the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The fundamental voltage phasor of the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The fundamental voltage phase is ahead of the second traction bus BB T2 Voltage transformer YHT2 Secondary side signal u T2 The fundamental voltage phase of the second single-phase compensation device CD 2 Active power target value P absorbed by the AC end 2 *With the third single-phase compensation device CD 3 Active power target value P absorbed by the AC end 3 *Interchange, second single-phase compensation device CD 2 The target value of reactive power absorbed by the AC end is Q 2 *With the third single-phase compensation device CD 3 The target value of reactive power absorbed by the AC end is Q 3 *exchange; According to the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *、Reactive power target value Q 1 *、Harmonic current target value i 1h * and its port voltage signal u T1 , get the first single-phase compensation device CD 1 Port current signal target value i CD1 *; According to the second single-phase compensation device CD 2 Active power target value P absorbed by the AC end 2 *、Reactive power target value Q 2 * and its port voltage signal (-u T2 ), and obtain the second single-phase compensation device CD 2 Port current signal target value i CD2 *; According to the third single-phase compensation device CD 3 Active power target value P absorbed by the AC end 3 *、Reactive power target value Q 3 * and its port voltage signal (u T2 -u T1 ), and obtain the third single-phase compensation device CD 3 Port current signal target value i CD3 *; According to the active power target value P released by the DC terminal of the energy storage device ES ES * and its port voltage signal u D , get the target value i of the current signal at the ES port of the energy storage device ES *.

[0015] A third aspect of the present invention provides a computer-readable storage medium having instructions stored thereon, which when executed on a computer enables the computer to execute the above-mentioned method for controlling an energy storage co-phase power supply system based on a V-connected traction transformer.

[0016] The working principle of the present invention is as follows: the coordinated control device first detects the power of the traction load, compares it with the historical statistical value of the traction load, and then considers the charge state of the energy storage device, calculates the charging and discharging power target values ​​and the power quality compensation power target values ​​of the three single-phase compensation devices and the energy storage device, and further generates the comprehensive output current target values ​​of each device respectively, and controls the three single-phase compensation devices in a grid-connected manner so that they output according to the comprehensive output current target values ​​respectively, and simultaneously completes the goals of charging and discharging control, same-phase power supply control, negative sequence compensation control, reactive power compensation control and harmonic compensation control, and controls the energy storage device converter in a grid-connected manner so that it outputs according to the comprehensive output current target value, and completes the control goal of charging and discharging, overcomes the difficulties of large traction load fluctuation, train regenerative braking energy utilization, train over-power phase stall, power quality management, etc. of the traditional electrified railway traction substation, and is applicable to various traction power supply modes. The control method is simple and efficient, which is conducive to improving the reliability of train operation, improving the utilization degree of train regenerative braking energy, reducing the electricity cost of the traction substation, and reducing the power fluctuation impact on the power system.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts three single-phase compensation devices and energy storage devices to perform charge and discharge control and power quality control. Each device is relatively independent in structure, simple to control and easy to implement. The three single-phase compensation devices and energy storage devices are connected in parallel at the DC end, and the DC voltage is stable, which is conducive to the realization of the control target; 2. The present invention is applicable to the same-phase power supply of energy storage in traction substations such as Vv traction transformers and Vy traction transformers, and is also applicable to traction power supply modes such as direct power supply mode, direct power supply mode with return line, AT power supply mode, BT power supply mode, etc., and has a wide range of applications; 3. The single-phase traction load and the AC ends of the three single-phase AC-DC converters of the present invention can be connected to any port of the secondary side of the V-connected traction transformer without changing the control method. The control method has good compatibility and strong versatility. 4. The control method of the present invention realizes the integrated control of system charging and discharging, same-phase power supply and power quality, cancels phase separation and performs negative sequence control, reactive power compensation and harmonic suppression during charging and discharging, which is conducive to the continuous and reliable operation of trains with power, and also realizes the active and reactive power decoupling control of single-phase compensation devices. The control method is simple and efficient; 5. The control method of the present invention reduces the load fluctuation of the primary side of the traction substation. Ideally, it can converge to the average power, effectively utilize the regenerative braking return power and reduce the maximum demand power of the traction substation, which is beneficial to saving the electricity bill expenditure of the traction substation and reducing the impact of large-scale and high-frequency power fluctuations on the power system; 6. The system structure and control method of the present invention can effectively control the power quality when the energy storage device is in normal, power-deficient, or power-overflow conditions, and has high operational flexibility and strong adaptability, ensuring that the power quality of the traction substation meets national standards, which is beneficial to the safe and reliable operation of the railway and power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings: Figure 1 It is a structural schematic diagram of the energy storage co-phase power supply system based on the V-connected traction transformer described in Example 1 of the present invention; Figure 2 It is a structural schematic diagram of the energy storage co-phase power supply system based on the V-connected traction transformer described in Example 2 of the present invention; Figure 3 It is a structural schematic diagram of the energy storage co-phase power supply system based on the V-connected traction transformer described in Example 3 of the present invention; Figure 4 is a flow chart of a control method for an energy storage co-phase power supply system based on a V-connected traction transformer as described in Embodiment 4 of the present invention; Figure 5 is a specific flow chart of determining the charge and discharge power described in Embodiment 4 of the present invention; Figure 6 is a specific flow chart of determining the power quality compensation power described in Embodiment 4 of the present invention; Figure 7 It is a specific flow chart of the generation of the comprehensive output current described in Example 4 of the present invention. DETAILED DESCRIPTION

[0019] In order to better understand the working principle of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention.

[0020] Example 1 like Figure 1 As shown, this embodiment provides an energy storage co-phase power supply system based on a V-connected traction transformer, wherein the energy storage co-phase power supply system includes a V-connected traction transformer TT for converting an external power supply provided by a three-phase power system into a voltage acceptable to a traction load, a single-phase compensation device for charge-discharge power conversion and power quality compensation, an energy storage device ES for charge-discharge power conversion and energy storage or release, and a coordination control device CS for detecting operating parameters of the traction load and the energy storage device, and controlling the operation of the single-phase compensation device and the energy storage device to achieve charge-discharge power conversion and power quality compensation.

[0021] The primary side of the V-connected traction transformer TT is connected to the three-phase power system PS, and the three terminals of the secondary side of the V-connected traction transformer TT are connected to the first traction bus BB one by one. T1 , the second traction bus BB T2 and grounding electrode GD, on the first traction bus BB T1 A traction load TL is connected between the grounding electrode GD, wherein the traction load TL is the total load of the traction network and the train connected thereto under the direct power supply mode, the direct power supply mode with a return line, and the BT power supply mode; the single-phase compensation device is the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 , the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The AC ends of the traction transformers are connected to the three different ports of the secondary side of the V-connected traction transformer, and the positive poles of the DC ends are connected in parallel and connected to the first DC bus BB. D1 , the negative poles of their DC terminals are connected in parallel and connected to the second DC bus BB D2 The positive electrode of the energy storage device ES is connected to the first DC bus BB D1 , its negative pole is connected to the second DC bus BB D2 The input end of the coordination control device CS is connected to the traction load feeder by the first traction bus BB T1 The current transformer LH connected in series L Secondary side signal i L , the first single-phase compensation device CD 1 The AC end is connected to the first traction bus BB T1 The current transformer LH connected in series 1 Secondary side signal i CD1 , the second single-phase compensation device CD 2 The AC end is connected in series with the current transformer LH of the grounding electrode GD. 2 Secondary side signal i CD2 , the third single-phase compensation device CD 3 The AC end is connected to the second traction bus BB T2 The current transformer LH connected in series 3 Secondary side signal i CD3 , the energy storage device ES is connected to the first DC bus BB D1 The DC current sensor LH connected in series ES Secondary side signal i ES , and the first traction bus BB T1 Voltage transformer YH T1Secondary side signal u T1 , the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 , connected to the first DC bus BB D1 and the second DC bus BB D2 DC voltage sensor YH D Secondary side signal u D The bidirectional signal ports of the coordination control device CS are respectively connected to the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 , the third single-phase compensation device CD 3 And the bidirectional signal port of the energy storage device ES is connected.

[0022] Optionally, the first single-phase compensation device CD 1 The first matching transformer MT is cascaded in sequence. 1 and the first single-phase AC-DC converter AD 1 , the second single-phase compensation device CD 2 The second matching transformer MT is cascaded in sequence. 2 and the second single-phase AC-DC converter AD 2 , the third single-phase compensation device CD 3 The third matching transformer MT is cascaded in sequence. 3 and the third single-phase AC-DC converter AD 3 .

[0023] Optionally, the energy storage device ES includes a DC-DC converter DD and an energy storage module SM which are cascaded in sequence. In this embodiment, the energy storage module SM can be any one of battery energy storage, supercapacitor energy storage or flywheel energy storage, or any combination of several of them.

[0024] Thus, the present embodiment comprehensively utilizes the single-phase compensation device and the energy storage device to perform charge and discharge control and power quality compensation control on the single-phase traction load. Each device is relatively independent in structure, simple to control, and easy to implement. The three single-phase compensation devices are used for both charge and discharge power conversion and power quality compensation, saving equipment investment. Moreover, the present embodiment adopts a system structure in which three single-phase compensation devices and the energy storage device are connected in parallel at the DC end, and the DC voltage is stable, which is conducive to the realization of the control target.

[0025] Example 2 like Figure 2As shown, this embodiment provides an energy storage co-phase power supply system based on a V-connected traction transformer, wherein the energy storage co-phase power supply system includes a V-connected traction transformer TT for converting an external power supply provided by a three-phase power system into a voltage acceptable to a traction load, a standby V-connected traction transformer TB used as a standby transformer for the V-connected traction transformer TT, a single-phase compensation device for charge-discharge power conversion and power quality compensation, an energy storage device ES for charge-discharge power conversion and energy storage or release, and a coordination control device CS for detecting operating parameters of the traction load and the energy storage device, and controlling the operation of the single-phase compensation device and the energy storage device to achieve charge-discharge power conversion and power quality compensation.

[0026] The primary side of the V-connected traction transformer TT is connected to the three-phase power system PS, and the three terminals of the secondary side of the V-connected traction transformer TT are connected to the first traction bus BB one by one. T1 , the second traction bus BB T2 and grounding electrode GD, on the first traction bus BB T1 A traction load TL is connected between the grounding electrode GD, wherein the traction load TL is the total load of the traction network and the train connected thereto under the direct power supply mode, the direct power supply mode with a return line, and the BT power supply mode; the single-phase compensation device is the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 , the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The AC ends of the traction transformers are connected to the three different ports of the secondary side of the V-connected traction transformer, and the positive poles of the DC ends are connected in parallel and connected to the first DC bus BB. D1 , the negative poles of their DC terminals are connected in parallel and connected to the second DC bus BB D2 The positive electrode of the energy storage device ES is connected to the first DC bus BB D1 , its negative pole is connected to the second DC bus BB D2 The input end of the coordination control device CS is connected to the traction load feeder by the first traction bus BB T1 The current transformer LH connected in series L Secondary side signal i L , the first single-phase compensation device CD 1 The AC end is connected to the first traction bus BB T1 The current transformer LH connected in series 1 Secondary side signal i CD1 , the second single-phase compensation device CD 2 The AC end is connected in series with the current transformer LH of the grounding electrode GD.2 Secondary side signal i CD2 , the third single-phase compensation device CD 3 The AC end is connected to the second traction bus BB T2 The current transformer LH connected in series 3 Secondary side signal i CD3 , the energy storage device ES is connected to the first DC bus BB D1 The DC current sensor LH connected in series ES Secondary side signal i ES , and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 , the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 , connected to the first DC bus BB D1 and the second DC bus BB D2 DC voltage sensor YH D Secondary side signal u D The bidirectional signal ports of the coordination control device CS are respectively connected to the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 , the third single-phase compensation device CD 3 And the bidirectional signal port of the energy storage device ES is connected.

[0027] The primary side of the standby V-connected traction transformer TB is connected to the three-phase power system PS, and any port of the secondary side is connected to the traction load TL; the three different ports of the secondary side of the standby V-connected traction transformer TB are also connected to the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 AC connection.

[0028] Optionally, the first single-phase compensation device CD 1 The first matching transformer MT is cascaded in sequence. 1 and the first single-phase AC-DC converter AD 1 , the second single-phase compensation device CD 2 The second matching transformer MT is cascaded in sequence. 2 and the second single-phase AC-DC converter AD 2 , the third single-phase compensation device CD 3 The third matching transformer MT is cascaded in sequence. 3 and the third single-phase AC-DC converter AD 3 .

[0029] Optionally, the energy storage device ES includes a DC-DC converter DD and an energy storage module SM which are cascaded in sequence. In this embodiment, the energy storage module SM can be any one of battery energy storage, supercapacitor energy storage or flywheel energy storage, or any combination of several of them.

[0030] In this way, in addition to the functions of in-phase power supply, energy storage control and power quality compensation, this embodiment also adopts a spare V-connected traction transformer TB, which can maintain the continuous operation and reliable power supply of the traction power supply system when the V-connected traction transformer TT is overhauled, maintained, or fails.

[0031] Example 3 like Figure 3 As shown, this embodiment provides an energy storage co-phase power supply system based on a V-connected traction transformer, wherein the energy storage co-phase power supply system includes a V-connected traction transformer TT for converting the external power provided by the three-phase power system into a voltage acceptable to the traction load in the AT power supply mode, a single-phase compensation device for charge-discharge power conversion and power quality compensation, an energy storage device ES for charge-discharge power conversion and energy storage or release, and a coordination control device CS for detecting the operating parameters of the traction load and the energy storage device, and controlling the operation of the single-phase compensation device and the energy storage device to achieve charge-discharge power conversion and power quality compensation.

[0032] The primary side of the V-connected traction transformer TT is connected to the three-phase power system PS, and three of the four terminals on the secondary side are in three-phase symmetrical voltage, and the fourth terminal is in two-phase symmetrical voltage with two of the three terminals. The two terminals and the fourth terminal are respectively connected to the first traction bus BB according to the symmetrical relationship of the two-phase voltage. T1 , grounding electrode GD and the first negative feeder bus BB F , another terminal of the three terminals is connected to the second traction bus BB T2 , on the first traction bus BB T1 , the grounding electrode GD and the first negative feeder bus BB F A traction load TL is connected between the two networks, wherein the traction load TL is the total load exhibited by the traction network and the trains connected thereto under the AT power supply mode.

[0033] The single-phase compensation device is a first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 , the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3The AC ends of the traction transformer are respectively connected to three different ports of the secondary three-phase symmetrical voltage terminal of the V-connected traction transformer, and the positive poles of the DC ends are connected in parallel and connected to the first DC bus BB D1 , the negative poles of their DC terminals are connected in parallel and connected to the second DC bus BB D2 The positive electrode of the energy storage device ES is connected to the first DC bus BB D1 , its negative pole is connected to the second DC bus BB D2 The input end of the coordination control device CS is connected to the traction load feeder by the first traction bus BB T1 The current transformer LH connected in series L Secondary side signal i L , the traction load negative feeder is composed of the first negative feeder bus BB F The current transformer LH connected in series F Secondary side signal i F , the first single-phase compensation device CD 1 The AC end is connected to the first traction bus BB T1 The current transformer LH connected in series 1 Secondary side signal i CD1 , the second single-phase compensation device CD 2 The AC end is connected in series with the current transformer LH of the grounding electrode GD. 2 Secondary side signal i CD2 , the third single-phase compensation device CD 3 The AC end is connected to the second traction bus BB T2 The current transformer LH connected in series 3 Secondary side signal i CD3 , the energy storage device ES is connected to the first DC bus BB D1 The DC current sensor LH connected in series ES Secondary side signal i ES , and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 , the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 , the first negative feeder bus BB F Voltage transformer YH F Secondary side signal u F , connected to the first DC bus BB D1 and the second DC bus BB D2 DC voltage sensor YH D Secondary side signal u D The bidirectional signal ports of the coordination control device CS are respectively connected to the first single-phase compensation device CD 1 , the second single-phase compensation device CD2 , the third single-phase compensation device CD 3 And the bidirectional signal port of the energy storage device ES is connected.

[0034] Optionally, the first single-phase compensation device CD 1 The first matching transformer MT is cascaded in sequence. 1 and the first single-phase AC-DC converter AD 1 , the second single-phase compensation device CD 2 The second matching transformer MT is cascaded in sequence. 2 and the second single-phase AC-DC converter AD 2 , the third single-phase compensation device CD 3 The third matching transformer MT is cascaded in sequence. 3 and the third single-phase AC-DC converter AD 3 .

[0035] Optionally, the energy storage device ES includes a DC-DC converter DD and an energy storage module SM which are cascaded in sequence. In this embodiment, the energy storage module SM can be any one of battery energy storage, supercapacitor energy storage or flywheel energy storage, or any combination of several of them.

[0036] The electrical quantity of the traction load in this embodiment is defined as follows: Feeder current transformer LH for traction load TL L Secondary side signal i L The polarity is determined by the first traction bus BB T1 The traction load TL flows into the positive and negative feeder current transformers LH F Secondary side signal i F The polarity is determined by the first negative feeder bus BB F The traction load TL flowing into the first traction bus BB is positive. T1 Voltage transformer YH T1 Secondary side signal u T1 The polarity is set to the first traction bus BB T1 The corresponding end of is positive, the corresponding end of the grounding electrode GD is negative, and the first negative feeder bus BB F Voltage transformer YH F Secondary side signal u F The polarity is set to the first negative feeder bus BB F The corresponding end of is positive, and the corresponding end of the ground electrode GD is negative. T1 and the signal i L , the signal u F and the signal i F The active power P absorbed by the traction load TL under the AT power supply mode can be calculated and superimposed separately. L , reactive power QL and harmonic current i Lh .

[0037] By this, this embodiment is applicable to the AT power supply mode V-connected traction substation same-phase power supply, energy storage control and power quality compensation, which expands the scope of application of the technical solution of the present invention and ensures the non-phase power supply and economical operation of high-speed railways and heavy-load railways.

[0038] Example 4 like Figure 4 As shown, this embodiment provides a control method for an energy storage co-phase power supply system based on a V-connected traction transformer, wherein the specific steps of the control method include: Step 1: System initialization: The coordination control device CS executes the definition of electrical quantities; Step 2: Calculation of charging and discharging power: The coordination control device CS first calculates the active power and reactive power currently absorbed by the traction load TL, and detects the current state of charge SOC of the energy storage device ES through the bidirectional signal between the coordination control device CS and the energy storage device ES. ES , and then the energy storage device ES and the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The charge and discharge power is determined; Step 3: Power quality compensation power calculation: The coordination control device CS performs the first single-phase compensation device CD according to the charge and discharge power calculation value. 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The power quality compensation power is determined; Step 4: The coordination control device CS performs the energy storage device ES and the first single-phase compensation device CD 1 , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The comprehensive output current is generated and the above devices are controlled to output current respectively. After a preset time step △t, it returns to step 2 and executes in a loop.

[0039] In this embodiment, the specific method of defining the electrical quantity in step 1 includes the following: Feeder current transformer LH for traction load TL L Secondary side signal i L The polarity is determined by the first traction bus BB T1 The traction load TL flowing into the first traction bus BB is positive. T1 Voltage transformer YH T1 Secondary side signal u T1 The polarity is set to the first traction bus BBT1 The corresponding end of is positive, and the corresponding end of the grounding electrode GD is negative. Based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TL L , reactive power Q L and harmonic current i Lh ; Second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The polarity is set to the second traction bus BB T2 The corresponding end of is positive, and the corresponding end of the ground electrode GD is negative; Connected to the first traction bus BB together with the traction load TL T1 The first single-phase compensation device CD 1 The secondary side signal of the AC current transformer is defined as i CD1 , the polarity is determined by the first traction bus BB T1 Flows into the first single-phase compensation device CD 1 Positive, based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the first single-phase compensation device CD 1 AC current transformer secondary side signal i CD1 Calculate the first single-phase compensation device CD 1 Active power P absorbed by the AC end 1 and reactive power Q 1 ; Connected to the second traction bus BB T2 The second single-phase compensation device CD between the grounding electrode GD 2 The secondary side signal of the AC current transformer is defined as i CD2 The polarity is set to flow from the grounding electrode GD into the second single-phase compensation device CD 2 is positive, based on the second single-phase compensation device CD 2 AC current transformer secondary side signal i CD2 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The inverted signal of the second single-phase compensation device CD is calculated 2 Active power P absorbed by the AC end 2 and reactive power Q 2 ; Connected to the first traction bus BB T1 and the second traction bus BB T2 The third single-phase compensation device CD between 3 The secondary side signal of the AC current transformer is defined as i CD3 , the polarity is determined to be the same as that of the second traction bus BB T2 Flows into the third single-phase compensation device CD 3 is positive, based on the third single-phase compensation device CD 3 AC current transformer secondary side signal i CD3 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 With the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The difference between the third single-phase compensation device CD is calculated 3 Active power P absorbed by the AC end 3 and reactive power Q 3 ; Energy storage device ES DC end current sensor LH ES Secondary side signal i ES The polarity is set to flow into the first DC bus BB D1 is positive, DC terminal voltage sensor YH D Secondary side signal u D The polarity is set to the first DC bus BB D1 The corresponding end is positive, the second DC bus BB D2 The corresponding end is negative, based on the DC end current sensor LH of the energy storage device ES ES Secondary side signal i ES And DC voltage sensor YH D Secondary side signal u D Calculate the active power P released by the energy storage device ES ES .

[0040] like Figure 5 As shown, the specific method for determining the charge and discharge power in step 2 of this embodiment includes the following: Update the sampling signals of all input terminals of the coordination control device CS, and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TL L , reactive power Q L and harmonic current iLh ; The historical operation status of the traction load TL is counted to obtain the historical average active power P within the preset time length before the current moment. Lav If there is no historical data of traction load, the historical average active power P Lav The initial value is set to zero, and the average active power of the traction load is counted and calculated after the operation starts; If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC allowed max , where 0 <SOC min <SOC max <1, then charge and discharge control is performed: the target discharge power value of the energy storage device ES is P ES *=P L -P Lav , the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=P Lav / 3-P L , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=P Lav / 3; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , the energy storage device ES power recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=-P RS , where P RS The energy storage device recovery power is a preset value, which is greater than zero and less than the historical average active power P Lav The absolute value of |P Lav | / 10, the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=P RS , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=0; If the current state of charge SOC of the energy storage device ESES Greater than or equal to the upper limit of the state of charge SOC max , the energy storage device overflow recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=P RS , the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *=-P RS , the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of active power absorbed by the AC end is P 2 *=P 3 *=0.

[0041] In the embodiment, the coordination control device CS regularly collects the traction bus voltage (u T1 ) and traction load current (TL), calculate the current active power P L , reactive power Q L and harmonic current i Lh At the same time, the system calculates the historical average active power PLav and calculates the state of charge (SOC) of the energy storage device. ES ) Determine the current state: Normal range (SOC min <SOC ES <SOC max ): The system performs dynamic energy balance control to allow the energy storage device to output power P ES *=P L -P Lav , reduce load fluctuations; three single-phase compensation devices cooperate to balance power; Low power range (SOC ES ≤SOC min ): Start the power failure protection control, the energy storage does not take on the load regulation temporarily, and only CD 1 Output a small amount of fixed power P RS , to prevent SOC from further decreasing and issue an alarm; Overflow range (SOC ES ≥SOC max ): Start the overflow processing control, force the energy storage to absorb a small amount of power P RS , releasing part of the energy and passing through CD 1 Absorb equal power, maintain bus power balance, and issue alarms at the same time.

[0042] The solution of the present invention calculates the traction load power and energy storage status in real time, dynamically adjusts the output power of the energy storage device and the compensation device, and realizes flexible response of the system in the three states of normal, power failure and power overflow, ensuring the stable operation of the power supply system and reducing bus power fluctuations. At the same time, it improves the energy storage utilization rate and ensures the safety and efficiency of the system.

[0043] like Figure 6 As shown, the specific method for determining the power quality compensation power in step three of this embodiment includes the following: Reactive power control: First single-phase compensation device CD 1 The target value of reactive power absorbed by the AC end is Q 1 *Meet the reactive power Q absorbed by the traction load TL L ; Harmonic current control: First single-phase compensation device CD 1 The target value of harmonic current absorbed by the AC end is i 1h *Meet the harmonic current i absorbed by the traction load TL Lh ; Perform negative sequence power control: If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC allowed max , then no negative sequence power control is performed: the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3 The target value of reactive power absorbed by the AC end is zero; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , or the SOC ES Greater than or equal to the upper limit of the state of charge SOC max , further judgment is needed, and the rules for further judgment are: According to the three-phase power system PS and the preset standard of power quality three-phase voltage unbalance, the single-phase power allowable value of the secondary side of the traction transformer TT connected to V is calculated by S AN Indicates that S AN ≥0, if the data is insufficient and cannot be calculated, the single-phase power allowable value S AN Use the preset value; when the active power P currently absorbed by the traction load TL L The modulus value of |P L |Less than or equal to the single-phase power allowable value S AN , then no negative sequence power control is performed, and the second single-phase compensation device CD 2 And the third single-phase compensation device CD 3The reactive power target value absorbed by the AC end is zero; if the module value |P L |Greater than the single-phase power allowable value S AN , then negative sequence power control is performed, and further judgment is made. The rules for further judgment are: If P L >0, the second single-phase compensation device CD 2 The reactive power target value absorbed by the AC end is Q 2 *=(S AN -P L ) / , the third single-phase compensation device CD 3 The reactive power target value absorbed by the AC end is Q 3 *=(P L -S AN ) / If P L <0, the second single-phase compensation device CD 2 The reactive power target value absorbed by the AC end is Q 2 *=-(P L +S AN ) / , the third single-phase compensation device CD 3 The reactive power target value absorbed by the AC end is Q 3 *=(P L +S AN ) / .

[0044] Thus, the system structure and control method of this embodiment can effectively control the power quality when the energy storage device is in normal, power-deficient, or power-overflowing states, with high operational flexibility and strong adaptability, ensuring that the power quality of the traction substation meets national standards, which is beneficial to the safe and reliable operation of the railway and power system.

[0045] like Figure 7 As shown, the specific method for generating the comprehensive output current in step 4 of this embodiment includes the following: The coordination control device CS detects the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The fundamental voltage phasor of the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The fundamental voltage phase is ahead of the second traction bus BB T2 Voltage transformer YH T2Secondary side signal u T2 The fundamental voltage phase of the second single-phase compensation device CD 2 Active power target value P absorbed by the AC end 2 *With the third single-phase compensation device CD 3 Active power target value P absorbed by the AC end 3 *Interchange, second single-phase compensation device CD 2 The target value of reactive power absorbed by the AC end is Q 2 *With the third single-phase compensation device CD 3 The target value of reactive power absorbed by the AC end is Q 3 *exchange; According to the first single-phase compensation device CD 1 Active power target value P absorbed by the AC end 1 *、Reactive power target value Q 1 *、Harmonic current target value i 1h * and its port voltage signal u T1 , get the first single-phase compensation device CD 1 Port current signal target value i CD1 *; According to the second single-phase compensation device CD 2 Active power target value P absorbed by the AC end 2 *、Reactive power target value Q 2 * and its port voltage signal (-u T2 ), and obtain the second single-phase compensation device CD 2 Port current signal target value i CD2 *; According to the third single-phase compensation device CD 3 Active power target value P absorbed by the AC end 3 *、Reactive power target value Q 3 * and its port voltage signal (u T2 -u T1 ), and obtain the third single-phase compensation device CD 3 Port current signal target value i CD3 *; According to the active power target value P released by the DC terminal of the energy storage device ES ES * and its port voltage signal u D , get the target value i of the current signal at the ES port of the energy storage device ES *.

[0046] In the embodiment of the present invention, the coordination control device CS compares the first traction bus (BB T1 ) and the second traction busbar (BB T2 ) on the fundamental voltage phasor (u T1 with u T2 ), determine the phase sequence relationship: If uT1 Phase ahead of u T2 : To ensure system balance and reasonable power transmission direction, automatically exchange CD 2 and CD 3 Active / reactive power target value (P 2 * and P 3 *, Q 2 *With Q 3 *Swap).

[0047] Then, the system calculates the target current signal (i CD1 *、i CD2 *、i CD3 *、i ES *), in order to accurately control the output and realize the joint regulation of active power, reactive power and harmonics.

[0048] This control strategy dynamically determines the phase of the fundamental voltage phasor of the traction busbar, flexibly adjusts the power allocation scheme of each compensation device, and generates port current instructions based on each power target value and real-time voltage signal to achieve precise control of multiple compensation targets (active power, reactive power, harmonics), enhance system adaptability and real-time performance, and ensure power supply stability and power quality.

[0049] Thereby, the control method of this embodiment realizes the integrated control of system charging and discharging, same-phase power supply and power quality, eliminates phase separation and performs negative sequence control, reactive power compensation and harmonic suppression during charging and discharging, which is conducive to the continuous and reliable energized operation of the train, and also realizes the active and reactive power decoupling control of the single-phase compensation device. The control method is simple and efficient.

[0050] The present invention also provides a computer-readable storage medium, which stores instructions, and when the instructions are run on a computer, the computer executes the above-mentioned energy storage co-phase power supply system control method based on a V-connected traction transformer.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy storage co-phase power supply system based on a V-connected traction transformer, characterized in that: The energy storage co-phase power supply system comprises: The V-connected traction transformer TT is used to transform the external power supply on the primary side to the traction bus on the secondary side. The primary side of the V-connected traction transformer TT is connected to the three-phase power system PS. The three terminals of the secondary side of the V-connected traction transformer TT are connected to the first traction bus BB one by one. T1 , the second traction bus BB T2 and grounding electrode GD, on the first traction bus BB T1 A traction load TL is connected between the grounding electrode GD; The single-phase compensation device is used for charging and discharging power conversion and power quality compensation, including a first single-phase compensation device CD1, a second single-phase compensation device CD2 and a third single-phase compensation device CD3; Energy storage device ES, used for charging and discharging power conversion and energy storage or release, the positive electrode of the energy storage device ES is connected to the first DC bus BB D1 , the negative pole is connected to the second DC bus BB D2 ; The coordination control device CS is used to detect the operating parameters of the traction load and the energy storage device ES, and control the operation of the single-phase compensation device and the energy storage device ES to achieve charging and discharging power conversion and power quality compensation; the input end of the coordination control device CS is connected to the following signals: The traction load feeder is composed of the first traction bus BB T1 The current transformer LH connected in series L Secondary side signal i L , the AC end of the first single-phase compensation device CD1 is connected to the first traction bus BB T1 The secondary side signal i of the series connected current transformer LH1 CD1 , the AC end of the second single-phase compensation device CD2 is connected in series with the grounding electrode GD by the current transformer LH2 secondary side signal i CD2 The AC end of the third single-phase compensation device CD3 is connected to the second traction bus BB T2 The secondary side signal i of the series connected current transformer LH3 CD3 , the energy storage device ES is connected to the first DC bus BB D1 The DC current sensor LH connected in series ES Secondary side signal i ES , and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 , the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 , connected to the first DC bus BB D1 and the second DC bus BB D2 DC voltage sensor YH D Secondary side signal u D ; The bidirectional signal port of the coordination control device CS is respectively connected to the bidirectional signal ports of the first single-phase compensation device CD1, the second single-phase compensation device CD2, the third single-phase compensation device CD3 and the energy storage device ES.

2. According to claim 1, a V-connected traction transformer-based energy storage co-phase power supply system is characterized in that: The AC ends of the first single-phase compensation device CD1, the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are respectively connected to three different ports of the secondary side of the V-connected traction transformer TT, and the positive poles of their DC ends are connected in parallel and connected to the first DC bus BB. D1 , the negative poles of their DC terminals are connected in parallel and connected to the second DC bus BB D2 ; The first single-phase compensation device CD1 includes a first matching transformer MT1 and a first single-phase AC-DC converter AD1 which are cascaded in sequence, the second single-phase compensation device CD2 includes a second matching transformer MT2 and a second single-phase AC-DC converter AD2 which are cascaded in sequence, and the third single-phase compensation device CD3 includes a third matching transformer MT3 and a third single-phase AC-DC converter AD3 which are cascaded in sequence.

3. The energy storage co-phase power supply system based on V-connected traction transformer according to claim 1 is characterized in that: The energy storage device ES includes a DC-DC converter DD and an energy storage module SM which are cascaded in sequence.

4. The energy storage co-phase power supply system based on V-connected traction transformer according to claim 1 is characterized in that: The energy storage co-phase power supply system also includes a standby V-connected traction transformer TB used as a standby transformer for the V-connected traction transformer TT. The primary side of the standby V-connected traction transformer TB is connected to the three-phase power system PS, and any one port of the secondary side of the standby V-connected traction transformer TB is connected to the traction load TL; the three different ports of the secondary side of the standby V-connected traction transformer TB are also connected one by one to the AC ends of the first single-phase compensation device CD1, the second single-phase compensation device CD2 and the third single-phase compensation device CD3.

5. A control method for a V-connected traction transformer-based energy storage co-phase power supply system, characterized in that: The control method is applied to the energy storage co-phase power supply system based on the V-connected traction transformer according to any one of claims 1 to 4, and is characterized in that the specific steps of the control method include: Step 1: System initialization: The coordination control device CS executes the definition of electrical quantities; Step 2: Calculation of charging and discharging power: The coordination control device CS first calculates the active power and reactive power currently absorbed by the traction load TL, and detects the current state of charge SOC of the energy storage device ES through the bidirectional signal between the coordination control device CS and the energy storage device ES. ES , and then determine the charge and discharge power of the energy storage device ES and the first single-phase compensation device CD1, the second single-phase compensation device CD2 and the third single-phase compensation device CD3; Step 3: Calculation of power quality compensation power: The coordination control device CS determines the power quality compensation power of the first single-phase compensation device CD1, the second single-phase compensation device CD2 and the third single-phase compensation device CD3 according to the calculated value of the charge and discharge power; Step 4: The coordination control device CS generates the comprehensive output current of the energy storage device ES and the first single-phase compensation device CD1, the second single-phase compensation device CD2 and the third single-phase compensation device CD3, and controls the above devices to output current respectively. After a preset time step △t, it returns to step 2 and executes in a loop.

6. A method for controlling an energy storage co-phase power supply system based on a V-connected traction transformer according to claim 5, characterized in that: The specific method for defining electrical quantities in step 1 is as follows: Feeder current transformer LH for traction load TL L Secondary side signal i L The polarity is determined by the first traction bus BB T1 The traction load TL flowing into the first traction bus BB is positive. T1 Voltage transformer YH T1 Secondary side signal u T1 Polarity is set to the first traction bus BB T1 The corresponding end of is positive, and the corresponding end of the grounding electrode GD is negative. Based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TL L , reactive power Q L and harmonic current i Lh ; Second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The polarity is set to the second traction bus BB T2 The corresponding end of is positive, and the corresponding end of the ground electrode GD is negative; Connected to the first traction bus BB together with the traction load TL T1 The secondary side signal of the current transformer at the AC end of the first single-phase compensation device CD1 is set to i CD1 , the polarity is determined by the first traction bus BB T1 The current flowing into the first single-phase compensation device CD1 is positive, based on the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the secondary side signal i of the current transformer at the AC end of the first single-phase compensation device CD1 CD1 The active power P1 and reactive power Q1 absorbed by the AC end of the first single-phase compensation device CD1 are calculated; Connected to the second traction bus BB T2 The secondary side signal of the current transformer at the AC end of the second single-phase compensation device CD2 between the grounding electrode GD is set to i CD2 The polarity is set as positive from the grounding electrode GD into the second single-phase compensation device CD2, based on the secondary side signal i of the current transformer at the AC end of the second single-phase compensation device CD2 CD2 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The active power P2 and reactive power Q2 absorbed by the AC end of the second single-phase compensation device CD2 are calculated by using the inverted signal; Connected to the first traction bus BB T1 and the second traction bus BB T2 The secondary side signal of the AC current transformer of the third single-phase compensation device CD3 is set to i CD3 , the polarity is determined to be the same as that of the second traction bus BB T2 The current flowing into the third single-phase compensation device CD3 is positive, based on the secondary side signal i of the current transformer at the AC end of the third single-phase compensation device CD3 CD3 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 With the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The difference is calculated to obtain the active power P3 and reactive power Q3 absorbed by the AC end of the third single-phase compensation device CD3; Energy storage device ES DC end current sensor LH ES Secondary side signal i ES The polarity is set to flow into the first DC bus BB D1 is positive, DC terminal voltage sensor YH D Secondary side signal u D The polarity is set to the first DC bus BB D1 The corresponding end is positive, the second DC bus BB D2 The corresponding end is negative, based on the DC end current sensor LH of the energy storage device ES ES Secondary side signal i ES And DC voltage sensor YH D Secondary side signal u D Calculate the active power P released by the energy storage device ES ES .

7. The control method of a V-connected traction transformer-based energy storage co-phase power supply system according to claim 5 is characterized in that: The specific method for determining the charge and discharge power in step 2 is as follows: Update the sampling signals of all input terminals of the coordination control device CS, and the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the feeder current transformer LH of the traction load TL L Secondary side signal i L Calculate the active power P absorbed by the traction load TL L , reactive power Q L and harmonic current i Lh ; The historical operation status of the traction load TL is counted to obtain the historical average active power P within the preset time length before the current moment. Lav If there is no historical data of traction load, the historical average active power P Lav The initial value is set to zero, and the average active power of the traction load is counted and calculated after the operation starts; If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC max , where 0 <SOC min <SOC max <1, then charge and discharge control is performed: the target discharge power value of the energy storage device ES is P ES *=P L -P Lav , the active power target value P1*=P absorbed by the AC end of the first single-phase compensation device CD1 Lav / 3-P L The target values ​​of active power absorbed by the AC end of the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are both P2*=P3*=P Lav / 3; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , the energy storage device ES power recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=-P RS , where P RS The energy storage device restores power, which is a preset value, and its value is greater than zero and less than the historical average active power P Lav The absolute value of the active power target value P1*=P absorbed by the AC end of the first single-phase compensation device CD1 RS , the target values ​​of active power absorbed by the AC ends of the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are both P2*=P3*=0; If the current state of charge SOC of the energy storage device ES ES Greater than or equal to the upper limit of the state of charge SOC max , the energy storage device overflow recovery control is performed and an alarm prompt is output: the target value of the energy storage device ES discharge power is P ES *=P RS , the active power target value absorbed by the AC end of the first single-phase compensation device CD1 is P1*=-P RS The target values ​​of active power absorbed by the AC ends of the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are both P2*=P3*=0.

8. The method for controlling an energy storage co-phase power supply system based on a V-connected traction transformer according to claim 5 is characterized in that: The specific method for determining the power quality compensation power in step 3 is as follows: Reactive power control: The reactive power target value Q1* absorbed by the AC end of the first single-phase compensation device CD1 meets the reactive power Q absorbed by the traction load TL L ; Harmonic current control: The harmonic current target value i absorbed by the AC end of the first single-phase compensation device CD1 1h *Meet the harmonic current i absorbed by the traction load TL Lh ; Perform negative sequence power control: If the current state of charge SOC of the energy storage device ES ES Greater than the lower limit of the allowed state of charge SOC min And it is less than the upper limit of the state of charge SOC max , then no negative sequence power control is performed: the reactive power target values ​​absorbed by the AC ends of the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are both zero; If the current state of charge SOC of the energy storage device ES ES Less than or equal to the lower limit of the allowed state of charge SOC min , or the SOC ES Greater than or equal to the upper limit of the state of charge SOC max , further judgment is needed, and the rules for further judgment are: According to the three-phase power system PS and the preset standard of power quality three-phase voltage unbalance, the single-phase power allowable value of the secondary side of the traction transformer TT connected to V is calculated by S AN Indicates that S AN ≥0, if the data is insufficient and cannot be calculated, the single-phase power allowable value S AN Use the preset value; when the active power P currently absorbed by the traction load TL L The modulus value of |P L |Less than or equal to the single-phase power allowable value S AN , then no negative sequence power control is performed, and the reactive power target values ​​absorbed by the AC ends of the second single-phase compensation device CD2 and the third single-phase compensation device CD3 are both zero; if the module value |P L |Greater than the single-phase power allowable value S AN , then negative sequence power control is performed, and further judgment is made. The rules for further judgment are: If P L >0, then the reactive power target value absorbed by the AC end of the second single-phase compensation device CD2 is Q2*=(S AN -P L ) / The reactive power target value absorbed by the AC end of the third single-phase compensation device CD3 is Q3*=(P L -S AN ) / If P L <0, then the reactive power target value absorbed by the AC end of the second single-phase compensation device CD2 is Q2*=-(P L +S AN ) / The reactive power target value absorbed by the AC end of the third single-phase compensation device CD3 is Q3*=(P L +S AN ) / .

9. The control method of a V-connected traction transformer-based energy storage co-phase power supply system according to claim 5, characterized in that: The specific method for generating the comprehensive output current in step 4 is as follows: The coordination control device CS detects the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 and the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The fundamental voltage phasor of the first traction bus BB T1 Voltage transformer YH T1 Secondary side signal u T1 The fundamental voltage phase is ahead of the second traction bus BB T2 Voltage transformer YH T2 Secondary side signal u T2 The fundamental voltage phase of the second single-phase compensation device CD2 is replaced by the active power target value P2* absorbed by the AC end of the second single-phase compensation device CD2 and the active power target value P3* absorbed by the AC end of the third single-phase compensation device CD3, and the reactive power target value Q2* absorbed by the AC end of the second single-phase compensation device CD2 and the reactive power target value Q3* absorbed by the AC end of the third single-phase compensation device CD3 are replaced; According to the active power target value P1*, reactive power target value Q1*, harmonic current target value i1 absorbed by the AC end of the first single-phase compensation device CD1, 1h * and its port voltage signal u T1 , get the target value i of the current signal at the port of the first single-phase compensation device CD1 CD1 *; According to the active power target value P2*, reactive power target value Q2* and its port voltage signal (-u T2 ), and obtain the target value i of the current signal at the port of the second single-phase compensation device CD2 CD2 *; According to the active power target value P3*, reactive power target value Q3* and its port voltage signal (u T2 -u T1 ), and obtain the target value i of the current signal at the port of the third single-phase compensation device CD3 CD3 *; According to the active power target value P released by the DC terminal of the energy storage device ES ES * and its port voltage signal u D , get the target value i of the current signal at the ES port of the energy storage device ES *.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, which, when executed on a computer, enable the computer to execute the energy storage co-phase power supply system control method based on a V-connected traction transformer as described in any one of claims 5 to 9.

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