A railway secondary traction side multi-level hybrid power regulation system and control method

Abstract

The present invention discloses a multi-level hybrid power regulation system and control method for the secondary traction side of a railway. A hybrid compensator of TSC+TSR+SVG is adopted, which is composed of an angular continuous SVG subsystem and an angular discrete SVC subsystem. The angular SVC discrete subsystem includes multiple groups of TSC and TSR; each phase chain of the angular SVG continuous subsystem is composed of multiple H-bridge cascades, which is easy to realize the individual control of each phase bridge chain and has the capability of reactive continuous output. By switching TSC and TSR to perform large-capacity reactive power and negative sequence discrete compensation, and then using the fully controlled SVG to perform continuous compensation and management of residual reactive power and harmonics, the power quality and operation stability of the railway system are maintained.

Description

Technical Field

[0001] The present invention relates to the field of railway secondary traction side power regulation, and in particular to a railway secondary traction side multi-level hybrid power regulation system and a control method. Background Art

[0002] With the rapid development of electrified railways, the impact of traction power supply network on power supply and consumption systems is becoming increasingly prominent. Because the railway traction system is a typical single-phase load, if balanced compensation is not performed, it will cause serious voltage imbalance at the public grid connection point, especially in weak grid areas with small short-circuit capacity, which will have a serious impact on other loads connected to the public grid.

[0003] At present, the passive control methods for negative sequence, harmonics and reactive power in railway traction network at home and abroad usually adopt static reactive power compensation devices (SVC) of thyristor switched capacitors (TSC) and thyristor switched reactors (TSR). For example, CN101882788A proposed a method and device for increasing the network voltage at the end of a long power supply arm of a heavy-duty railway. A direct-hung thyristor controlled reactor type SVC is installed at the outlet of the main transformer, and multiple groups of TSC devices are installed at the end of the autotransformer at the end of the long power supply ratio for compensation to improve the grid voltage. However, the load fluctuation amplitude at the end of the electrified railway power supply arm is large, and the switching frequency is high, which can easily cause over-compensation and under-compensation of the power supply, resulting in large voltage fluctuations.

[0004] Static VAR generator (SVG) has the characteristics of high power density, high efficiency, high response, and fast speed, and has been widely used in comprehensive compensation applications for high-speed railway power quality. For example, CN101630848A uses SVG to balance the single-phase load of the railway. Its input end is connected to the low-voltage side of the transformer, which can compensate for reactive power, negative sequence current and harmonic current. However, since SVG is usually connected to the three-phase side with a higher voltage level, it requires an additional three-phase step-down transformer with a relatively large capacity, which also increases the investment cost. Therefore, in order to achieve low-cost and high-reliability railway traction network power quality management, it is necessary to combine the characteristics and advantages of passive filters and static VAR generators to study the hybrid power compensation system and its control strategy on the secondary traction side of the railway. Summary of the invention

[0005] In order to overcome the above disadvantages, the present invention provides a multi-level hybrid power regulation control method for the secondary traction side of a railway, which is applied to the multi-level hybrid power regulation system for the secondary traction side of a railway. The system consists of an angular discrete SVC subsystem and an angular continuous SVG subsystem; the angular continuous SVG subsystem includes three cascaded LC-SVGs, each of which is composed of a multi-level cascaded H-bridge, a coupling capacitor and a filter inductor connected in series; the angular discrete SVC subsystem consists of a thyristor switched capacitor TSC and a thyristor switched reactor TSR; wherein the αN phase requires three groups of TSCs, with capacities of I(M), II(M), and III(2M) respectively; the βN phase requires three groups of TSRs, with capacities of I(-M), II(-M), and III(-2M) respectively; the αβ phase requires three groups of TSCs + three groups of TSRs, with capacities of I(M), II(M), III(2M), IV(-M), V(-M), and VI (-2M) respectively, wherein the expression of M is as follows:

[0006] (1);

[0007] Among them, PT is the rated power of a single locomotive, and UT represents the effective value of the voltage of the traction network;

[0008] The control method comprises:

[0009] Step 1: Obtain the large-capacity reactive power and negative-sequence discrete compensation instructions of the angular discrete SVC subsystem; specifically:

[0010] According to the number of locomotives N per phase bridge arm of the railway traction network α , N β , the three-phase current on the secondary traction side is calculated I sα , I sβ and I sN for:

[0011] (2);

[0012] Based on the three-phase current of the secondary traction side I sα , I sβ and I sN According to the Steinmetz superposition principle, the required three-phase compensation admittance B is calculated r αβ , B r βN , B r Nα , based on the three-phase compensation admittance Br αβ , B r βN , B r Nα , calculate the three-phase compensation phase current value I αr , I βr , I Nr According to the principle that the passive compensator is the compensation subject, the reactive compensation interval is discretized, the number and capacity of thyristor switched capacitors (TSC) and thyristor switched reactors (TSR) in each phase of the discrete SVC subsystem are determined, and the three-phase switching instructions T of TSC and TSR under different operating conditions are generated. α , T β , T N as the discretization compensation instruction;

[0013] Step 2: Obtain small capacity reactive power and negative sequence continuous compensation instructions of the angular continuous SVG subsystem; specifically:

[0014] Sampling traction network three-phase voltage u sα , u sβ and u sN , the reactive current reference value is obtained through calculation I q ref Harmonic current command value i h ref ; Sample the capacitor voltage of each phase of the angular continuous SVG subsystem to obtain the average value u dc , the active current reference value is obtained through calculation I d ref , the reactive current reference value I q ref , the harmonic current command value i h ref and the active current reference value I d ref The three-phase link modulation signal is obtained by current inner loop tracking control calculation m αβ , m βN and m Nα ;

[0015] According to the three-phase voltage of the traction network u sα ,u sβ and u sN Calculate the negative sequence component U nd and U nq , the negative sequence component U nd and U nq The modulation signal correction value ∆ is obtained by calculation m αβ ,∆ m βN and ∆ m Nα ;

[0016] The modulation signal correction value ∆ m αβ ,∆ m βN and ∆ m Nα The modulation signal m αβ , m βN and m Nα Correction is performed to obtain the PWM modulation instruction of the switch tube of the angular continuous SVG subsystem as the continuous compensation instruction.

[0017] Furthermore, in the step 1,

[0018] The three-phase compensation admittance B r αβ , B r βN and B r Nα for:

[0019] (3);

[0020] The rotation factor a = e j120° , U is the effective value of the traction line voltage, I sα , I sβ and I sN Respectively represent the three-phase currents on the secondary traction side.

[0021] Further, according to the three-phase compensation admittance B r αβ , B rβN and B r Nα , calculate the three-phase compensation phase current value I αr , I βr , I Nr for:

[0022] (4);

[0023] in, U aβ , U Na and U βN is the three-phase voltage on the secondary traction side.

[0024] Furthermore, in step 2, according to the three-phase voltage of the traction network u sα , u sβ and u sN , the voltage reference value is obtained through the fundamental voltage effective value detection module U gf , the voltage reference value U gf With reference value U gf ref The difference obtained after comparison is used to obtain the reactive current reference value through the PI controller. I q ref ;

[0025] Furthermore, in step 2, according to the three-phase voltage of the traction network u sα， u sβ and u sN , the voltage reference value is obtained through the harmonic voltage detection module u h , multiply by the harmonic damping resistance 1 / K to get the harmonic current command value i h ref ;

[0026] Furthermore, in step 2, the capacitor voltages of each phase of the angular continuous SVG subsystem are sampled to obtain an average value. u dc , the average value u dc With DC voltage reference V dcref The difference obtained after comparison is used to obtain the active current reference value through the PI controller. I d ref .

[0027] Furthermore, in step 2, the modulation signal correction value ∆ m αβ ,∆ m βN and ∆ m Nα The calculation process is:

[0028] Sampling angle type continuous subsystem phase link current I αβ SVG , I βN SVG and I Nα SVG , after the star-three transformation and Park transformation, the negative sequence current value is obtained I nd SVG and I nq SVG ;

[0029] The U nd The first difference obtained by comparing with 0 is calculated by the PI controller to obtain the negative sequence active current reference value I nd ref , and then the negative sequence active current reference value I nd ref and I nd SVG The second difference obtained by comparison is used to obtain the voltage reference value through the PI controller. U nd r ;

[0030] The U nq The third difference value obtained by comparing with 0 is calculated by the PI controller to obtain the negative sequence reactive current reference value I nq ref , and then the negative sequence reactive current reference value I nq ref and I nq SVG The fourth difference obtained by comparison is used to obtain a voltage reference value through a PI controller.U nq r ; U nd r and U nq r The modulation signal correction value ∆ is obtained by dq-abc negative sequence coordinate transformation m αβ ,∆ m βN and ∆ m Nα .

[0031] A multi-level hybrid power regulation system for the secondary traction side of a railway is also provided, which is used to implement a multi-level hybrid power regulation control method for the secondary traction side of a railway. The voltage phases of the three cascaded LC-SVG terminals differ by 120 degrees. Each phase of the secondary side of the V / v traction transformer supplies power to two power supply arms, and two locomotives run on each of the power supply arms, with a total of 25 operating conditions.

[0032] A power regulation device is also provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the power regulation device runs the computer program through the processor to implement a multi-level hybrid power regulation control method on the secondary traction side of a railway.

[0033] A computer-readable storage medium is also provided, comprising a processor, wherein the computer-readable storage medium stores a computer program, and the processor executes the computer program to implement a multi-level hybrid power regulation control method for a secondary traction side of a railway.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention proposes a multi-level hybrid power regulation system and control method for the secondary traction side of railways. By connecting the SVG+TSC+TSR power quality management system on the secondary traction side, the withstand voltage requirements of equipment and components are reduced, saving costs. SVG adopts an angular connection, and each phase chain is composed of multiple H bridge cascades. The voltage borne by each phase chain is the line voltage, which makes it easy to realize the individual control of each phase bridge chain and has the capability of reactive continuous output.

[0036] According to the actual operating conditions of railway locomotives, TSC and TSR are switched to perform large-capacity reactive power and negative sequence discrete compensation, and then fully controlled SVG is used to perform continuous compensation and management of residual reactive power and harmonics. Due to the low cost and high reliability of TSC and TSR, this hybrid system can greatly reduce the compensation capacity of the active part SVG and the cost of the overall system device. At the same time, continuous compensation with SVG makes the entire hybrid power compensation system more accurate, realizing low-cost, high-efficiency reactive power, negative sequence and harmonic power quality comprehensive compensation control of the railway system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of a multi-level hybrid power regulation system on the secondary traction side of a railway;

[0038] Figure 2 It is a schematic diagram of the dual-line traction mode of the V / v traction power supply system;

[0039] Figure 3 This is a block diagram of the multi-level hybrid power regulation control strategy for the secondary traction side of the railway; Figure 3 (a) is the calculation block diagram of TSC and TSR switching instructions. Figure 3 (b) is the closed-loop control block diagram of LC-SVG. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] First embodiment:

[0042] Figure 1 This is a schematic diagram of the multi-level hybrid power regulation system on the secondary traction side of the railway. The 220kV three-phase power grid outputs 27.5kV traction grids on both sides through V / V transformers ( α , βPhase) and N-phase grounding terminal. The hybrid power compensation system is connected to the secondary traction side, including an angle-type continuous SVG subsystem and an angle-type discrete SVC subsystem. The angle-type continuous SVG subsystem includes three cascaded LC-SVGs, each of which is composed of a multi-level cascaded H-bridge, a coupling capacitor and a filter inductor in series, and is respectively connected across the phases on the secondary traction side. The terminal voltages of the three bridge arms of the cascaded LC-SVG differ by 120 degrees in phase, so the Steinmetz balanced compensation principle can be used to compensate for the negative sequence current in the load. Each phase of the angle-type discrete SVC subsystem is configured with a corresponding number of thyristor-switched capacitors (TSC) and thyristor-switched reactors (TSR) according to the actual operating conditions of the train, and are respectively connected across the phases on the secondary traction side.

[0043] Figure 2 The diagram is a schematic diagram of the dual-line traction mode of the V / v traction power supply system. The primary side of the transformer is 220kV and the secondary side is 2×27.5kV. Considering the autotransformer (AT), the contact wire (+27.5kV) is directly connected to the feeder (-27.5kV) and AT to form a 55kV power supply system. The locomotive track is connected to the AT neutral line, so that the voltage between the contact wire and the locomotive track is 27.5kV. Considering that the locomotive speed can reach 300km / h and the minimum tracking interval is usually 3 minutes, usually a maximum of two locomotives are allowed to run on the same line. Since the high-speed railway system uses dual lines, the possible locomotive load combinations in the railway traction power supply system are usually 5×5=25.

[0044] Second embodiment:

[0045] Figure 3 This is a block diagram of the multi-level hybrid power regulation control strategy on the secondary traction side of the railway.

[0046] The overall control strategy of the angular continuous SVG subsystem and the angular discrete SVC subsystem is as follows: First, according to the number of locomotives N per phase arm of the railway traction network, α , N β , the three-phase current on the secondary traction side is calculated I sα , I sβ and I sN Then, according to the principle of passive compensator as compensation subject, the three-phase switching instructions (T α , T β , T N), which is the number of switching groups of the three phases. The compensation of negative sequence and reactive power by TSC and TSR is discrete, so the angle-type continuous SVG subsystem is added to continuously compensate the remaining compensation. By detecting the three-phase grid voltage, extracting the negative sequence component, and then performing closed-loop control through the negative sequence voltage regulator, the negative sequence current command signal that the SVG needs to output is obtained. The negative sequence command current signal and the negative sequence component in the SVG current are closed-loop controlled to obtain the negative sequence voltage command signal that the SVG needs to output.

[0047] The three-phase switching instructions of TSC and TSR are calculated as follows: Figure 3 (a) As shown in Figure 2, according to the number of locomotives N in each phase of the railway traction network α , N β , the three-phase current on the secondary traction side is calculated I sα , I sβ and I sN for:

[0048] (1);

[0049] in, P T is the rated power of a single locomotive, U T Indicates the effective value of the voltage of the traction network.

[0050] In order to suppress the three-phase ( α , β , N) is unbalanced, and a corresponding three-phase compensation current is superimposed on the unbalanced three-phase current using the Steinmetz superposition principle, so that the three-phase current is balanced. According to the Steinmetz superposition principle, the primary three-phase compensation admittance B can be obtained from the above formula r αβ , B r βN and B r Nα for:

[0051] (2);

[0052] Among them, the rotation factor a = e j120° , U is the effective value of the traction network line voltage. The required compensation admittance B can be calculated by formula (2): r αβ , B r βN , B r NαAccording to the principle that the passive compensator is the compensation subject, the interval is discretized to determine the three-phase switching instructions (T α , T β , T N ) as the discretization compensation instruction.

[0053] According to the operating conditions of the high-speed railway traction system, the interval of reactive compensation is determined. According to the principle that the passive compensator is the main body of compensation, the interval is discretized to determine the capacity and number of reactive compensation devices. Generally, the discretized unit capacity is selected as the capacity of the smallest group in the passive compensator group, and then the capacity of the active compensator is determined. Generally speaking, the capacity of the active compensator is set to a unit capacity of 0.5 to 1. For safety reasons, during the operation of the high-speed railway, a maximum of two locomotives run on each power supply arm, and each phase supplies power to two power supply arms, so there are a total of 25 operating conditions. Assume that the load current corresponding to each locomotive is 1pu. According to the load current of the traction network i Lα and i Lβ , calculate the required compensation admittance B r αβ , B r βN , B r Nα And the required three-phase compensation phase current value I αr , I βr , I Nr for:

[0054] (3);

[0055] According to the calculation results, β The admittance of phase N is negative, that is, this phase needs to supplement inductive reactive power. α The admittance of phase N is positive, which means that this phase needs to supplement capacitive reactive power. Based on this, the number and capacity of TSC and TSR deployed in each phase are determined. Under different locomotive operating conditions, the coordinated operation of TSC and TSR can basically compensate for the negative sequence and reactive current caused by the locomotive load, and convert the three-phase unbalanced current into a three-phase balanced current.

[0056] The closed-loop control of LC-SVG is as follows: Figure 3 (b) As shown. Fully controlled SVG is used to continuously compensate for residual reactive power and harmonics to maintain the power quality and operational stability of the railway system. On the basis of the original reactive power compensation, SVG adds negative sequence voltage suppression function to realize the negative sequence voltage compensation function on the grid side.

[0057] In order to realize positive sequence reactive power and harmonic control, the three-phase voltage of the traction network is sampled. usα， u sβ and u sN , the voltage reference value is obtained by detecting the effective value of the fundamental voltage U gf , the voltage reference value U gf With reference value U gf ref The difference obtained after comparison is used to obtain the reactive current reference value through the PI controller. I q ref . Traction network three-phase voltage u sα， u sβ and u sN , the voltage reference value is obtained by harmonic voltage detection u h , the voltage reference value u h Multiply by the harmonic damping resistance 1 / K to get the harmonic current command value i h ref The controller is essentially a P controller, and k is the controller coefficient used to adjust the effect of the control loop on harmonic suppression. The capacitor voltages of each phase of the angular continuous SVG subsystem are sampled to obtain the average value. u dc , the average value u dc With DC voltage reference V dc ref The difference obtained after comparison is used to obtain the active current reference value through the PI controller. I d ref . I q ref , i h ref and I d ref The three-phase link modulation signal is obtained through SVG current inner loop tracking control m αβ , m βN and m Nα To achieve negative sequence voltage control, the link current of each phase of SVG is sampled. I αβ SVG ,I βN SVG and I Nα SVG , after the star-three transformation and Park transformation, the negative sequence current value is obtained I nd SVG and I nq SVG Then calculate the three-phase voltage of the traction network u sα， u sβ and u sN The negative sequence component is obtained U nd and U nq . U nd and U nq The first difference and the third difference are respectively compared with 0, and the first difference and the third difference are respectively passed through the PI controller to obtain the negative sequence active current reference value I nd ref and negative sequence reactive current reference value I nq ref The negative sequence active current reference value I nd ref and the negative sequence reactive current reference value I nq ref Respectively I nd SVG and I nq SVG After comparison, the second difference and the fourth difference are obtained, and the second difference and the fourth difference are respectively used to obtain a voltage reference value through a PI controller U nd r and U nq r , the voltage reference value U nd r and U nq r The modulation signal correction value ∆ is obtained by dq-abc negative sequence coordinate transformation m αβ ,∆ m βN and ∆ mNα Finally, the modulation signal correction value ∆ m αβ ,∆ m βN and ∆ m Nα The modulation signal m αβ , m βN and m Nα Correction is performed to obtain the PWM modulation instruction of the switch tube of the angular continuous SVG subsystem as the continuous compensation instruction.

[0058] Table 1 is a summary of the compensation admittance and compensation current corresponding to different working conditions. The table summarizes the compensation admittance, compensation current value and TSC and TSR input sequence under 25 load conditions. It can be seen from the table that the compensation capacity corresponding to 0.333pu is the minimum unit capacity value and is represented by M. The mathematical expression is as follows:

[0059] (4);

[0060] but α The N phase requires three sets of TSCs, with capacities of I(M), II(M), and III(2M) respectively. β The N phase requires three sets of TSRs, with capacities of I(-M), II(-M), and III(-2M) respectively. αβ Three groups of TSC + three groups of TSR are needed, with capacities of I (M), II (M), III (2M), IV (-M), V (-M), VI (-2M). According to the above table, the TSC and TSR invested under 25 different working conditions can be analyzed as shown in Table 1.

[0061] Through calculation, it is found that under different locomotive operating conditions, the coordinated operation of TSC and TSR can basically compensate for the negative sequence and reactive current caused by the locomotive load and convert the three-phase unbalanced current into a three-phase balanced current.

[0062] Table 1 Summary of compensation admittance and compensation current corresponding to different working conditions

[0063]

[0064] Third embodiment:

[0065] A power regulation device is also provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the power regulation device runs the computer program through the processor to implement a multi-level hybrid power regulation control method on the secondary traction side of a railway.

[0066] A computer-readable storage medium is also provided, comprising a processor, wherein the computer-readable storage medium stores a computer program, and the processor executes the computer program to implement a multi-level hybrid power regulation control method for a secondary traction side of a railway.

[0067] The power regulation device may include a processor and a memory. The power regulation device may correspond to a computing device having various processing functions.

[0068] The processor controls all functions of the electronic device. For example, the processor controls all functions of the electronic device by executing a program stored in a memory on the electronic device. The processor can be implemented by a central processing unit (CPU), a graphics processing unit (GPU), an application processor (AP), an artificial intelligence processor chip (IPU), etc. provided in the electronic device. However, the present application is not limited thereto.

[0069] The memory is hardware for storing various data processed in the electronic device. For example, the memory can store processed data and data to be processed in the electronic device. The memory can store data sets involved in the process of the power dispatching and self-driving method that the processor has processed or is to process, such as collected operating data, control parameters, etc. In addition, the memory can store applications, drivers, etc. to be driven by the electronic device. In an embodiment, the memory may include at least one of a hard disk drive (HDD), a solid-state drive (SSD), a high-density flash memory (CF), a secure digital (SD) card, a micro secure digital (Micro-SD) card, a mini secure digital (Mini-SD) card, an extreme digital (xD) card, caches, or a memory stick.

[0070] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the technical field without departing from the purpose of the present invention. In addition, the undescribed parts involved in the present invention are the same as the prior art, or are implemented by using the prior art.

Claims

1. A multi-level hybrid power regulation control method for secondary traction side of railway, characterized by: Applied to the multi-level hybrid power regulation system on the secondary traction side of railways, the system consists of two parts: an angular discrete SVC subsystem and an angular continuous SVG subsystem; each link of the angular continuous SVG subsystem consists of a multi-level cascaded H bridge, a coupling capacitor and a filter inductor in series; the angular discrete SVC subsystem consists of a thyristor switched capacitor TSC and a thyristor switched reactor TSR; wherein α The N phase requires three sets of TSCs, with capacities of I(M), II(M), and III(2M); β The N phase requires three sets of TSRs, with capacities of I(-M), II(-M), and III(-2M); αβ The phase requires three sets of TSC + three sets of TSR, with capacities of I (M), II (M), III (2M), IV (-M), V (-M), VI (-2M), where M is expressed as follows: (1)； Among them, P T is the rated power of a single locomotive, U T Indicates the effective value of the voltage of the traction network; The control method comprises: Step 1: Obtain the large-capacity reactive power and negative-sequence discrete compensation instructions of the angular discrete SVC subsystem; specifically: According to the number of locomotives N per phase bridge arm of the railway traction network α , N β , the three-phase current on the secondary traction side is calculated I sα , I sβ and I sN for: (2)； Based on the three-phase current of the secondary traction side I sα , I sβ and I sN According to the Steinmetz superposition principle, the required three-phase compensation admittance B is calculated r αβ , B r βN , B r Nα , based on the three-phase compensation admittance B r αβ , B r βN , B r Nα , calculate the three-phase compensation phase current value I αr , I βr , I Nr According to the principle that the passive compensator is the compensation subject, the reactive compensation interval is discretized, the number and capacity of thyristor switched capacitors TSC and thyristor switched reactors TSR placed in each phase of the discrete SVC subsystem are determined, and the three-phase switching instructions TSC and TSR under different operating conditions are generated. α , T β , T N as the discretization compensation instruction; Step 2: Obtain small capacity reactive power and negative sequence continuous compensation instructions of the angular continuous SVG subsystem; specifically: Sampling traction network three-phase voltage u sα , u sβ and u sN , the reactive current reference value is obtained through calculation I q ref Harmonic current command value i h ref ; Sample the capacitor voltage of each phase of the angular continuous SVG subsystem to obtain the average value u dc , the active current reference value is obtained through calculation I d ref , the reactive current reference value I q ref , the harmonic current command value i h ref and the active current reference value I d ref The three-phase link modulation signal is obtained by current inner loop tracking control calculation m αβ , m βN and m Nα ; According to the three-phase voltage of the traction network u sα , u sβ and u sN Calculate the negative sequence component U nd and U nq , the negative sequence component U nd and U nq The modulation signal correction value ∆ is obtained by calculation m αβ ,∆ m βN and ∆ m Nα ; The modulation signal correction value ∆ m αβ ,∆ m βN and ∆ m Nα The modulation signal m αβ , m βN and m Nα Correction is performed to obtain the PWM modulation instruction of the switch tube of the angular continuous SVG subsystem as the continuous compensation instruction.

2. The control method according to claim 1, characterized in that: In the step 1, The three-phase compensation admittance B r αβ , B r βN and B r Nα for: （3）； The rotation factor a = e j120° , U is the effective value of the traction line voltage, I sα , I sβ and I sN Respectively represent the three-phase currents on the secondary traction side.

3. The control method according to claim 2, characterized in that: According to the three-phase compensation admittance B r αβ , B r βN and B r N α , calculate the three-phase compensation phase current value I αr , I βr , I Nr for: （4）； in, U αβ , U Nα and U βN is the three-phase voltage on the secondary traction side.

4. The control method according to claim 1, characterized in that: In the step 2, according to the three-phase voltage of the traction network u sα , u sβ and u sN , the voltage reference value is obtained through the fundamental voltage effective value detection module U gf , the voltage reference value U gf With reference value U gf ref The difference obtained after comparison is used to obtain the reactive current reference value through the PI controller. I q ref .

5. The control method according to claim 4, characterized in that: In the step 2, according to the three-phase voltage of the traction network u sα， u sβ and u sN , the voltage reference value is obtained through the harmonic voltage detection module u h , multiply by the harmonic damping resistance 1 / K to get the harmonic current command value i h ref .

6. The control method according to claim 5, characterized in that: In the step 2, the capacitor voltages of each phase of the angular continuous SVG subsystem are sampled to obtain an average value. u dc , the average value u dc With DC voltage reference V dc ref The difference obtained after comparison is used to obtain the active current reference value through the PI controller. I d ref .

7. The control method according to claim 6, characterized in that: In the step 2, the modulation signal correction value ∆ m αβ ,∆ m βN and ∆ m Nα The calculation process is: Sampling angle type continuous subsystem phase link current I αβ SVG , I βN SVG and I Nα SVG , after the star-three transformation and Park transformation, the negative sequence current value is obtained I nd SVG and I nq SVG ; The U nd The first difference obtained by comparing with 0 is calculated by the PI controller to obtain the negative sequence active current reference value I nd ref , and then the negative sequence active current reference value I nd ref and I nd SVG The second difference obtained by comparison is used to obtain the voltage reference value through the PI controller. U nd r ; The U nq The third difference value obtained by comparing with 0 is calculated by the PI controller to obtain the negative sequence reactive current reference value I nq ref , and then the negative sequence reactive current reference value I nq ref and I nq SVG The fourth difference obtained by comparison is used to obtain a voltage reference value through a PI controller. U nq r ; Said U nd r and U nq r The modulation signal correction value ∆ is obtained by dq-abc negative sequence coordinate transformation m αβ ,∆ m βN and ∆ m Nα .

8. A railway secondary traction side multi-level hybrid power regulation system, used to implement the railway secondary traction side multi-level hybrid power regulation control method according to any one of claims 1 to 7, characterized in that: The angular continuous SVG subsystem includes three cascaded LC-SVGs, each of which is composed of a multi-level cascaded H-bridge, a coupling capacitor and a filter inductor in series; the terminal voltages of the three cascaded LC-SVGs differ by 120 degrees in phase; each phase of the secondary side of the V / v traction transformer supplies power to two power supply arms, and two locomotives run on each of the power supply arms, with a total of 25 operating conditions.

9. A power regulating device, characterized in that: The power regulating device comprises a processor and a memory, wherein the memory is used to store a computer program, and the power regulating device runs the computer program through the processor to implement the control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer comprises a processor, the computer-readable storage medium stores a computer program, and the processor executes the computer program to implement the control method according to any one of claims 1 to 7.

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