Power quality management method for parallel multiplexing topology based on location tracking lmi

Abstract

The present application relates to a kind of parallel multiple topology power quality treatment methods based on position tracking LMI, comprising the following steps: for locomotive traction power supply system, based on parallel multiple RPC topology structure, establish RPC amplitude-phase control model;By constructing state space model, design LMI constraint and feedforward compensation, construct with d-axis modulation voltage and q-axis modulation voltage as input, DC bus voltage and phase synchronization signal as output LMI controller, realize stable gradual position tracking.Compared with prior art, the present application has the advantages of realizing the optimization control of traction power supply system, multi-objective collaborative optimization and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a parallel multi-topology power quality management method based on position tracking LMI. BACKGROUND

[0002] In the new era of high-speed railway technology, traction power supply technology plays a crucial role. With the continuous development of railway transportation and the widespread application of power electronics technology, the scale and complexity of the traction power supply system are increasing. However, there are various types of nonlinear loads in the traction substation and various locomotives of rail transit, which can cause significant power quality problems.

[0003] Among them, harmonic pollution is one of the main problems. Harmonic current can cause grid voltage distortion, increase line loss, affect the normal operation of electrical equipment, and even cause equipment failure and protection device malfunction. In addition, the existence of reactive power can have a negative impact on the traction power supply system, specifically manifested as a decrease in system power factor and an increase in grid loss.

[0004] To solve the above-mentioned power quality problems, the traditional method includes the use of passive filters (PPF). However, passive filters have some limitations, such as being able to filter only specific harmonics, being prone to resonance with the grid, and having limited compensation effect. At this time, active power filters emerge as the times require. Active power filters have the advantages of fast dynamic response, high compensation accuracy, and the ability to simultaneously compensate for harmonics and reactive power.

[0005] However, the use of active power filters (APF) alone has inherent defects such as high cost and limited compensation capacity.

[0006] Chinese patent application publication No. CN118842015A discloses a power quality management method and system based on multi-RPC, which compensates for negative sequence and harmonics in high-speed rail through a multi-RPC system, solves the problems of energy waste and grid instability caused by harmonic current during the operation of the motor train unit, achieves grid current balance and voltage stability, and improves energy utilization and equipment life. However, the amplitude and phase control of the limited LMI has some defects in the traction power supply system: the optimization freedom is limited, the fixed gain structure cannot dynamically coordinate the position tracking accuracy (DC voltage / phase error), disturbance rejection (H∞ performance), and loop current suppression, leading to tracking overshoot and excessive loop current under regenerative braking conditions; the dynamic adaptability is weakened, the response time lags behind the grid voltage fluctuation and load mutation, which is inferior to the real-time optimization capability of the position tracking LMI; the disturbance suppression is rigid, the preset static H∞ constraint cannot adapt to the sudden change of regenerative braking energy, and the voltage fluctuation rate is worse than that of the position tracking LMI. These defects significantly degrade the overall performance of the high-speed rail under dynamic conditions.

[0007] In summary, in order to meet the requirements of the traction power supply system for power quality, it is of important practical significance to design a power quality treatment method based on a parallel multi-RPC topology structure. SUMMARY

[0008] The purpose of the present application is to overcome the defects of the prior art and provide a parallel multi-RPC topology power quality treatment method based on position tracking LMI to solve or partially solve the problems of harmonic amplification, negative sequence unbalance degree, and the like.

[0009] The purpose of the present application can be achieved by the following technical solutions:

[0010] In one aspect of the present application, a parallel multi-RPC topology power quality treatment method based on position tracking LMI is provided, comprising the following steps:

[0011] For a locomotive traction power supply system, a RPC amplitude and phase control model is established based on a parallel multi-RPC topology structure.

[0012] By constructing a state space model, designing LMI constraints and feedforward compensation, an LMI controller is constructed with the d-axis modulation voltage and the q-axis modulation voltage as inputs and the DC bus voltage and the phase synchronization signal as outputs, so as to realize stable and gradual position tracking.

[0013] As a preferred technical solution, the construction process of the RPC amplitude and phase control model comprises the following steps:

[0014] A steady-state mathematical model of a single-sided voltage source converter of a railway power regulator RPC is established.

[0015] The detected two-arm load current is calculated.

[0016] The compensated two-sided traction current is calculated.

[0017] The total compensation current of the RPC system is obtained.

[0018] As a preferred technical solution, the steady-state mathematical model is:

[0019]

[0020] wherein i d , i q , and u dc are the d-axis, q-axis currents and DC voltage of the single-sided voltage source converter of the railway power regulator RPC, R, L, and C are resistance, inductance, and capacitance, ω is the angular frequency, k c is the amplitude adjustment coefficient of the voltage u c , δ is the phase angle of the inverter output u s , and Us The reference vector u s is the effective value.

[0021] As a preferred technical solution, the load current of the two arms is:

[0022]

[0023] where i αr and i βr are the load currents of the two arms, I αrf and I βrf are the fundamental current amplitudes, I αrn and I βrn are the n-th harmonic current amplitudes, θ α and θ β are the phase differences, which are positive when the load is capacitive and negative when the load is inductive, θ αn , θ βn are the initial phases on both sides of the n-th harmonic, ω is the angular frequency, and t represents time.

[0024] As a preferred technical solution, the compensated bilateral traction current is:

[0025]

[0026] where i′ α and i′ β are the compensated bilateral traction currents, I p ′ represents the active current amplitude after active power transfer balance, ω is the angular frequency, and t represents time.

[0027] As a preferred technical solution, the total compensation current of the RPC system is:

[0028]

[0029] where i and i are the compensation currents on both sides of the RPC system, i′ α and i′ β are the compensated bilateral traction currents, and i αr and i βr are the load currents of the two arms.

[0030] As a preferred technical solution, the state space model is modeled as:

[0031]

[0032] where x(t)∈R n is the system state vector, including the d-axis current, the q-axis current, the DC voltage error, and the DC voltage integral compensation term; u(t)∈Rm For control input, including d-axis modulation voltage and q-axis modulation voltage, d(t) is external disturbance, including train power step, network voltage amplitude change and braking feedback power; y(t) is output, including DC link voltage and grid phase angle obtained by position tracking; A, B, C and D are system parameter matrices.

[0033] As a preferred technical solution, the LMI controller is in the form of:

[0034] u(t)=Kx(t)+K r r(t)

[0035] Wherein, K is a feedback gain matrix, K r is a feedforward gain matrix, r(t) is a reference signal, including a set voltage and an ideal phase.

[0036] As a preferred technical solution, the feedback gain matrix is solved under stability constraints and H performance constraints, and the feedforward gain matrix is solved by feedforward compensation, wherein,

[0037] The stability constraint is:

[0038]

[0039] In the formula, T represents transposition, and P is a symmetric positive definite matrix;

[0040] The H performance constraint is:

[0041]

[0042] In the formula, γ is a disturbance suppression level, and I is a unit matrix,

[0043] The feedforward gain matrix is solved by the following formula:

[0044] K r =(C[-(A+BK] -1 B) -1

[0045] In the formula, () -1 Indicates inversion.

[0046] Another aspect of the application provides an electronic device, comprising one or more processors, a memory and one or more programs stored in the memory, the one or more programs comprising instructions for executing the aforementioned LMI-based parallel multi-connection topology power quality control method based on position tracking.

[0047] Compared with the prior art, the application has at least one of the following beneficial effects:

[0048] (1) Realize the optimization control to the traction power supply system: the present application is through in the locomotive traction power supply system with increasing based on parallel multiple RPC topology structure, RPC parallel access traction power supply network, each converter independently undertakes the compensation task of corresponding power supply area. When the system runs, each traction line is equivalent to a single-phase load, through the active / reactive power efficient transmission conversion between two-phase load, guarantee the safe and reliable operation of train, through the design of LMI controller to adjust the DC bus voltage and phase synchronization signal, improve the overall efficiency and stability of the power supply system, provide strong support for the high performance operation of traction power supply network.

[0049] (2) Multi-objective collaborative optimization: the present application designs LMI controller to process stability P, tracking accuracy K r , anti-interference gamma at the same time, through Dd(t) modeling energy mutation, H∞ constraint gamma inhibits its influence on DC voltage. The dynamic robustness of K and the static accuracy of Kr are solved in the convex optimization framework, which breaks through the inherent contradiction of speed-stability-accuracy in traditional amplitude and phase control. The gain matrix is essentially the optimal solution under multi-objective constraints, which realizes the true sense of adaptive control in strong disturbance and nonlinear working conditions of high-speed rail traction network. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 It is the flow chart of the parallel multiple topology power quality treatment method based on position tracking LMI in the embodiment;

[0051] Figure 2 It is the main circuit diagram of the train in the embodiment;

[0052] Figure 3 It is the simulink circuit diagram of HAPF in the embodiment;

[0053] Figure 4 It is the traction network side current waveform diagram in the embodiment;

[0054] Figure 5 It is the traction network side current harmonic component 1-100 harmonic comparison diagram before and after filtering of RPC and HAPF filtering under four working conditions when there is one train on the alpha side and the beta side in the embodiment;

[0055] Figure 6 It is the traction network current FFT diagram before and after HAPF+lmi modulation when there are two trains on the alpha side and one train on the beta side in the embodiment;

[0056] Figure 7 It is the traction network side current harmonic component 1-100 harmonic comparison diagram before and after filtering of RPC and HAPF filtering under four working conditions when there are two trains on the alpha side and the beta side in the embodiment;

[0057] Figure 8 For the traction net side current harmonic components 1-100th harmonic comparison chart of the RPC and HAPF filtered α side and β side of each one train and two trains in four working conditions

[0058] Figure 9 For the traction net side current harmonic components 1-100th harmonic comparison chart of the RPC and HAPF filtered α side and β side of each one train and two trains in four working conditions

[0059] Figure 10 For the traction net side current harmonic components 1-100th harmonic comparison chart of the RPC and HAPF filtered α side and β side of each one train and two trains in four working conditions

[0060] Figure 11 For the traction net side current harmonic components 1-100th harmonic comparison chart of the RPC and HAPF filtered α side and β side of each one train and two trains in four working conditions

[0061] Figure 12 For the traction net side current harmonic components 1-100th harmonic comparison chart of the RPC and HAPF filtered α side and β side of each one train and two trains in four working conditions DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work should fall within the protection scope of the present application.

[0063] Embodiment 1

[0064] In view of the problems of overcoming harmonic amplification, high negative sequence unbalance degree and the like existing in the foregoing prior art, the embodiment provides a parallel multi-plexing topology power quality treatment method based on position tracking LMI. A self-built traction power supply system regenerative braking model is used to obtain more abundant train operation conditions, the harmonic and negative sequence problems caused by locomotive traction and braking at the power grid side in various operation conditions are analyzed in detail, the HAPF is used for harmonic treatment from the perspective of multiple operation conditions, and the method is more in line with the engineering practice of the traction power supply system.

[0065] In the method, first, the system power quality problem is analyzed, then an engineering model including a traction power supply system and related key equipment is built, a four-plexing railway power regulator (RPC) model based on an LMI algorithm is designed, a motor train unit operation model is constructed and multiple operation conditions are designed, a hybrid active power filter (HAPF) parameter adaptability adjustment strategy is developed, and finally the system comprehensive treatment effect is verified through multiple operation condition simulation.

[0066] See Figure 1 This method includes the following steps:

[0067] Step S1: Analyze the power quality issues of the system.

[0068] As a key component of the traction power supply network, the traction transformer primarily undertakes voltage regulation and energy distribution functions. In railway power supply systems, the power system transmits three-phase alternating current (AC), while traction equipment such as EMU trains require single-phase AC to operate. The traction transformer acts as an "energy translator," converting three-phase AC to single-phase AC, enabling electrical energy to be transmitted to the EMU in a suitable form. The operating parameters of the traction power supply model are shown in Table 1.

[0069] Table 1 Operating parameters of traction power supply system

[0070]

[0071] Step S2: Build an engineering model that includes the traction power supply system and related key equipment.

[0072] Step S3: Innovatively design a quadruple railway power regulator (RPC) model based on the LMI algorithm.

[0073] By introducing equipment such as railway power regulators (RPCs), optimized control of the traction power supply system is achieved. In practice, RPCs are connected in parallel to the traction power supply network, with each converter independently undertaking compensation tasks for its corresponding power supply area. During system operation, each traction line is equivalent to a single-phase load. Efficient active / reactive power transmission and conversion between two-phase loads ensures safe and reliable train operation. Furthermore, this scheme significantly improves the overall efficiency and stability of the power supply system, providing strong support for the high-performance operation of the traction power supply network.

[0074] The steady-state mathematical model of a single-sided voltage source converter in a railway power regulator (RPC) can be expressed as:

[0075]

[0076] Set the detected load current of the two arms to i αr i βr Then we have:

[0077]

[0078] In Equation 3-2, I αrf and I βrf It is the amplitude of the fundamental current, I αrn and I βrn It is the amplitude of the nth harmonic current, θ α With θ βis the phase difference, positive when the load is capacitive, negative when the load is inductive, θ αn , θ βn is the initial phase of both sides when the n-th harmonic. 2-2 can be expanded by combining the trigonometric formula:

[0079]

[0080] The load current i αrp and i βrp of α, β arms are derived from the principle of phase detection method, and further simplified:

[0081]

[0082] The compensated bilateral traction current is:

[0083]

[0084] Where I′ p represents the active current amplitude after active power balance, ω is the angular frequency, and t represents time.

[0085] Therefore, the total compensation current command of the RPC system is:

[0086] In actual rail transit control systems, there are some interference factors that are difficult to avoid. In order to meet the stability and robustness of the system, the control strategy adopted by the RPC amplitude and phase control is the LMI algorithm control based on the position tracking system, and the characteristics are:

[0087] Optimizing the RPC amplitude and phase control to the LMI-based algorithm design can realize the control algorithm design of position tracking.

[0088] Its state equation can be expressed as:

[0089] Where: x(t)∈R n is the system state vector; u(t)∈R m is the control input; d(t) is the external disturbance; y(t) is the output (including the position tracking signal); A, B, C, D are system parameter matrices.

[0090] Position tracking accuracy: make the output y(t) accurately track the reference signal r(t), i.e. lim t→∞ (y(t)-r(t))=0

[0091] Anti-interference: suppress the influence of external disturbance d(t) on tracking performance.

[0092] Robust stability: maintain the stability of the closed-loop system under parameter perturbation or input limitation.

[0093] State feedback controller design: Controller form: u(t) = Kx(t) + K r r(t)

[0094] Where K is the feedback gain matrix, K r is the feedforward gain matrix.

[0095] Design LMI: Design LMI through Lyapunov function V(x) = x T Px to ensure system stability:

[0096]

[0097] Define H performance index as:

[0098]

[0099] Use it to suppress the influence of disturbance, where γ is the disturbance suppression level.

[0100] Solve LMI to get gain matrix K and K r .

[0101] Error definition: Tracking error e(t) = y(t) - r(t), by state extension, the error dynamics is included in the system equation:

[0102] The closed-loop system equation becomes: r u(t) = Kx + K

[0103] By LMI constraint, ensure that the eigenvalues of closed-loop system matrix A+BK are located in the left half complex plane, so as to realize asymptotic tracking and ensure the stability of closed-loop system.

[0104] In this embodiment, the definitions of some abstract symbols are shown in Table 2:

[0105] Table 2 Definition of Abstract Symbols

[0106]

[0107] Specifically, the process of implementing steps of LMI-based amplitude and phase control is as follows:

[0108] Step S301, establish a state space model matching Simulink structure, construct parameter matrices A, B, C, D:

[0109]

[0110]

[0111] In this diagram, rows A represent the dynamics of active current, reactive current, voltage error, and the integral element (corresponding to 1 / Period in the Mean module). Rows B, C, and D represent the control input matrix, output matrix (U... dc and θ), feedforward matrix.

[0112] Step S302: Design LMI constraints.

[0113] This includes stability constraints and H∞ performance constraints.

[0114] The stability constraint is:

[0115]

[0116] The performance constraints for H∞ are:

[0117]

[0118] The feedback gain K is obtained by solving the LMI system.

[0119] Step S303: Feedforward compensation design to improve tracking performance.

[0120] The feedforward gain K is calculated using the following formula. r This allows y(t) to accurately track r(t):

[0121] K r =(C[-(A+BK)] -1 B) -1

[0122] Step S304: Build the LMI controller.

[0123] Input: State vector x = [Δi p ,Δi q ,∫U dc ,ΔU dc ]. Where Δi p For active current tracking error, Δi q The reactive current tracking error reflects the power control accuracy.

[0124] Output: Modulated signal u = [v α ;v β ]. Where v α v β This refers to the modulation voltage command in the α and β coordinate system.

[0125] The formula is: u(t) = Kx(t) + K r r(t).

[0126] Step S305, Disturbance immunity verification.

[0127] Test under three disturbance types: train regenerative braking, grid voltage dip (20%), load step (1MW to 5MW), where the test index is U dc <±5%, LMI control target is H∞ performance. Under grid voltage dip, the test index is phase synchronous recovery time <10ns, LMI control target is eigenvalue left half plane to ensure stability. Under load step, the test index is dynamic response time <15ms, LMI control target is LMI optimization closed-loop pole.

[0128] By designing an LMI controller, stability (P>0), tracking accuracy (K r ), and disturbance rejection (γ) can be handled simultaneously. By modeling energy mutation through Dd(t), H∞ constraint γ suppresses its influence on U dc , and the mean value calculation module is retained, but the integral control is replaced by LMI, which improves the dynamic response speed. When the system parameters are perturbed, such as filter inductance L±20%, the LMI solution set remains stable, avoiding the risk of loss of control.

[0129] Step S4: Construct the EMU operation model and design multiple operating conditions.

[0130] The train main circuit usually adopts a bidirectional four-quadrant converter structure, which can be simplified by an equivalent model, and the equation is:

[0131]

[0132] where V is the low-voltage side voltage phasor, is the low-voltage side fundamental current phasor, is the fundamental phasor of the PWM modulation voltage. The EMU uses pulse width modulation technology combined with voltage and current double-loop proportional integral regulation mechanism to accurately control the phase, thereby ensuring that the AC side meets the specified power factor standard. The voltage loop adjusts the amplitude of the modulation wave signal in combination with the dynamic adjustment of the current loop to maintain the stability of the intermediate DC bus voltage.

[0133] Combined with the locomotive model and the traction power supply system, multiple operating conditions of the locomotive are designed to analyze the grid side negative sequence and harmonics. The operating condition description is shown in Table 3.

[0134] Table 3 Operating condition description

[0135]

[0136] Step S5: Develop a hybrid active filter (HAPF) parameter adaptability strategy.

[0137] The power quality treatment method of the parallel multiple RPC topology structure is adopted in the embodiment, wherein the HAPF is composed of the modular combination of the passive filter (PPF) and the active filter (APF), see Figure 3 The Simulink diagram of the HAPF is shown in FIG. 2, and the HAPF is used to suppress the harmonics in the traction system and improve the power quality. Although the comprehensive performance of the passive filter is not as good as that of the active filter, the passive filter has a significant effect on eliminating the harmonics of fixed frequencies. In the specific design, the fixed single-resonant filter and the wide-band attenuation module are designed in parallel, and the selective filtering is realized by matching the inductance and capacitance parameters corresponding to the 5th, 7th and 11th harmonics. The additional high-pass network is constructed in the form of a resistor-capacitor combination structure, which focuses on weakening the rapid harmonic components generated by the switching high-frequency disturbance, and further improves the harmonic treatment ability of the system. As known from the circuit basis, the impedance Z n of the n-th PPF at the frequency ω fn is as follows:

[0138] wherein R n represents the resistance of the n-th passive filter, ω a represents the frequency of the a-th passive filter (a is a positive integer), ω n represents the frequency of the n-th PPF, L n represents the inductance of the n-th PPF, and C n represents the capacitance of the n-th PPF.

[0139] The capacitive reactive power compensated by the DC side capacitor of the active filter APF is as follows:

[0140] ΔE(t)=Sk

[0141]

[0142] wherein ΔE(t) represents the change value of the capacitor in one period, S represents the compensation size, k represents the transformation ratio, C represents the DC side capacitor, ΔE m represents the voltage fluctuation range, U * m represents the stabilized value. The equivalent impedance of the output filter capacitor is as follows:

[0143] The i p -i q improved method based on the instantaneous reactive power theory is adopted in the embodiment. The active and reactive currents corresponding to i p and i q are as follows: i and i

[0144]

[0145] For the harmonic problem of the above working condition, the HAPF filter is used for filtering processing, and the parameter setting is shown in Table 4:

[0146] Table 4 HAPF filter filtering parameters

[0147]

[0148] Step S6: Multi-working condition simulation verification system comprehensive treatment effect.

[0149] In the experiment, the power of the two traction transformers of the embodiment is 8x10 6 VA and 12.5x10 6 VA respectively. The traction power supply system converts the input voltage into a voltage suitable for the load through two transformers with different turns ratios, and delivers power to the load through the V / v wiring mode. This system design can effectively meet the power supply requirements of the traction motor in rail transit. See Figure 2 for the main circuit diagram of the train.

[0150] See Figure 4 The embodiment shows the grid-side current waveform at 0s-1s, and the three-phase current fluctuates up and down when the locomotive working condition changes. See Figure 5 It can be seen that the traction grid-side current harmonics decrease at 0-10 times and 50-60 times. See Figure 6 It can be seen that the traction grid-side current harmonics decrease at 0-10 times and 50-60 times. See Figure 7 It can be seen that after RPC and HAPF filtering, the traction grid current harmonics decrease significantly at low-order harmonics and 50-60 times and 90-100 times. See Figure 8 It can be seen that after RPC and HAPF filtering, the traction grid-side current harmonics decrease significantly at low-order harmonics and 50-60 times. See Figure 9 It can be seen that after RPC and HAPF filtering, the traction grid-side current harmonics decrease at low-order harmonics and 50-60 times. See Figure 10 The relationship between the harmonic content and the harmonic order of the traction grid-side current under different working conditions is shown. It can be seen from the figure that after HAPF+LMI modulation, the 0-50 times harmonic content under each working condition is reduced. See Figure 11 The relationship between the harmonic content and the harmonic order of the traction grid-side current under different working conditions is shown. It can be seen from the figure that after HAPF+LMI modulation, the 0-10 times and 50-60 times harmonic content is significantly reduced.

[0151] To sum up, the embodiment realizes the comprehensive compensation of active power, reactive power and harmonic by connecting four RPCs in parallel into the traction power supply system, adopting the position tracking LMI amplitude-phase control strategy, and combining the hybrid energy storage device composed of lithium battery and flywheel energy storage, and simultaneously stores and recycles the electric energy, thereby significantly improving the energy utilization efficiency. For the actual circuit of the locomotive, the system adopts the PWM control technology and the double closed-loop PI control strategy to accurately adjust the phase and ensure the stability and high efficiency of the system operation.

[0152] Embodiment 2

[0153] On the basis of embodiment 1, the embodiment provides an electronic device, comprising one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs comprise instructions for executing the position tracking LMI-based parallel multi-topology power quality treatment method of embodiment 1.

[0154] As Figure 12 described, at the hardware level, the electronic device comprises a processor, an internal bus, a network interface, a memory and a non-volatile memory, and of course can also comprise other hardware required by business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs to realize the above-mentioned method. Of course, in addition to the software implementation, the present application does not exclude other implementation manners, such as logic devices or the combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices. Figure 1

[0155] The memory can comprise a non-permanent memory in a computer readable medium, random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer readable medium.

[0156] ​Computer-readable media includes permanent and non-permanent, movable and non-movable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0157] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for power quality management based on location tracking (LMI) in parallel multiplexing topology, characterized in that, It comprises the following steps: For a locomotive traction power supply system, an RPC amplitude-phase control model is established based on a parallel multi-RPC topology structure; By constructing a state space model, designing an LMI constraint and feedforward compensation, an LMI controller is constructed with the d-axis modulation voltage and the q-axis modulation voltage as inputs and the DC bus voltage and the phase synchronization signal as outputs, so that stable and gradual position tracking is realized, The state space model is modeled as: wherein, is the system state vector, including d-axis current, q-axis current, DC voltage error and DC voltage integral compensation term; is the control input, including d-axis modulation voltage and q-axis modulation voltage, is the external disturbance, including train power step, grid voltage amplitude variation and braking feedback power; is the output, including DC link voltage and grid phase angle obtained by position tracking; is the system parameter matrix, The LMI controller is in the form of: wherein, is a feedback gain matrix, is a feedforward gain matrix, is a reference signal, including a set voltage and an ideal phase, Under the stability constraint and the H performance constraint, the feedback gain matrix is solved, and the feedforward gain matrix is solved through feedforward compensation, wherein, The stability constraint is: wherein denotes the transpose, is a symmetric positive definite matrix; The H performance constraint is: wherein is the disturbance rejection level, is the identity matrix, The feedforward gain matrix is solved by using the following formula: In the formulae, denotes the inverse.

2. The LMI based shunt multilevel topology power quality mitigation method according to claim 1, wherein, The construction process of the RPC amplitude-phase control model comprises the following steps: A steady-state mathematical model of a railway power regulator (RPC) single-sided voltage source converter is established; A detected two-arm load current is calculated; A compensated double-sided traction current is calculated; An RPC system total compensation current is obtained.

3. The LMI based shunt multilevel topology power quality mitigation method according to claim 2, wherein, The steady-state mathematical model is: wherein , , are the d-axis, q-axis currents and the DC voltage of a single-sided voltage source converter of a railway power conditioner RPC, respectively, , , are the resistance, inductance, capacitance, respectively, is the angular frequency, is the voltage amplitude regulation factor, is the phase angle of the inverter output , is the effective value of the reference vector .

4. The LMI based shunt multilevel topology power quality mitigation method according to claim 2, wherein, The two-arm load current is: wherein, , are the load currents of the two arms respectively, and are the fundamental current amplitudes, and are the n-th harmonic current amplitudes, and are the phase differences, which are positive when the load is capacitive and negative when the load is inductive, , are the initial phases of the n-th harmonic on both sides, is the angular frequency, denotes time.

5. The LMI based shunt multilevel topology power quality mitigation method according to claim 2, wherein, The compensated double-sided traction current is: wherein, , are the compensated bilateral traction currents, respectively, denotes the active current amplitude after active power transfer balancing, is the angular frequency, denotes time.

6. The LMI based shunt multilevel topology power quality mitigation method according to claim 2, wherein, The RPC system total compensation current is: wherein, , are the compensation currents on both sides of the RPC system, respectively, , are the compensated traction currents on both sides, respectively, , are the load currents of both arms, respectively.

7. An electronic device, comprising: The device comprises one or more processors, a memory and one or more programs stored in the memory, and the one or more programs comprise instructions for executing the parallel multi-RPC topology power quality treatment method based on position tracking LMI as claimed in any one of claims 1-6.

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