Control method of four-quadrant rectifier of voltage source high-speed train with additional frequency damping

Abstract

The application provides a voltage source type high-speed train four-quadrant rectifier control method with introduced frequency additional damping. The application provides an improved voltage source type control scheme for the high-speed train four-quadrant rectifier, the traction transformer collects the voltage of the connection point of the vehicle and the traction network, the line total current effective value and the DC bus voltage of the DC side; first, the instantaneous reactive power Q and the active power P of the network side are calculated according to the collected data, the potential amplitude signal in the converter is obtained through the reactive loop; the V q FF additional damping is introduced in the active loop to calculate the synchronous phase angle; the control inner loop in the controller generates the PWM modulation signal for driving the four-quadrant rectifier according to the potential amplitude reference signal and the synchronous phase. The voltage source type control mode scheme is adopted to autonomously construct the voltage and the frequency, and the steady-state operation problem under the constant power characteristic under the weak railway power network can be solved.

Description

Technical Field

[0001] This invention relates to the field of four-quadrant converter technology for locomotives and rolling stock, and in particular to a control method for a high-speed train four-quadrant rectifier that introduces frequency-additional damping. Background Technology

[0002] As electrified railways enter a new phase, new railways are generally showing a trend of significantly increased power supply distances due to multiple factors such as environmental protection, construction difficulty, and economic costs. For example, the Sichuan-Tibet Railway faces long gradients and weak power grids, with single-section gradients reaching up to 72 kilometers and gradients as high as 30%. Planned undersea tunnel railways, such as those across the Qiongzhou Strait, Bohai Strait, and Taiwan Strait, have undersea sections of 80 kilometers, 105 kilometers, and 130 kilometers respectively. For operational safety and cost control considerations, these projects generally tend to eliminate the separate power supply phases on long gradients or avoid setting up traction substations on undersea sections, thus extending the single-arm power supply range of the traction power supply system from the traditional 20 kilometers to over 100 kilometers. This extended power supply distance leads to a significant increase in the total line impedance and a decrease in voltage stability. Simultaneously, multi-train operation on the same network over long sections has become the norm, creating typical "high impedance, weak power grid" operating conditions. Faced with this emerging and complex power supply structure, traditional control schemes face severe challenges in terms of system robustness and voltage stability, and the dynamic stability of railway traction systems urgently requires new control ideas and methods.

[0003] With the significant increase in the distance between power supply sections of newly built electrified railways (such as the Sichuan-Tibet Railway and the Strait Tunnel project, where the power supply section is over 100 kilometers), the line impedance has increased dramatically, leading to "multi-car shared network" operation scenarios. This results in the traction power supply system exhibiting typical characteristics of "high impedance and weak grid." While emerging voltage source control schemes have proven to have good stability under weak grid conditions, their application in the special scenario of railways requires specialized improvements to the corresponding control strategies, especially considering the issues that arise under constant traction power conditions.

[0004] To effectively address the common "vehicle-grid" oscillation problem in train traction power supply systems, existing technologies mostly rely on hardware methods (such as adding filters) for suppression. However, hardware solutions suffer from high costs and poor flexibility. One existing technology, focusing on software control, for four-quadrant converter control in locomotives and rolling stock includes:

[0005] (1) Design of oscillation identification and extraction mechanism:

[0006] This scheme extracts the high-frequency oscillation component contained in the current signal by real-time sampling of the grid-side AC current of the four-quadrant converter and processing its d-axis component with a high-pass filter. This high-frequency component serves as a "damping compensation factor" to indicate the intensity of system oscillation, thus providing a basis for oscillation suppression.

[0007] (2) Adaptive feedback control method based on current loop:

[0008] This scheme introduces an adaptive feedback mechanism into the dual closed-loop control structure of a four-quadrant converter. A damping compensation factor is injected into the d-axis current loop via negative feedback, thereby dynamically adjusting the grid-side AC current reference signal to achieve real-time cancellation of oscillations in the vehicle-grid system. This method uses a PI controller as the core of the inner loop, supplemented by delay compensation, switch modeling, and converter modeling modules to form a complete control loop.

[0009] (3) Design of the hardware and software co-architecture of the control system:

[0010] To implement the aforementioned control strategy, this scheme proposes a control system architecture including a sampling module, an acquisition module, and a feedback module. The feedback module generates a reference current signal that is in phase and frequency with the grid based on the grid voltage phase and frequency detected by the phase-locked loop, achieving precise synchronization of current control. The entire control logic is implemented at the software level, avoiding additional hardware investment and offering advantages such as low cost and flexible implementation.

[0011] The disadvantages of the existing four-quadrant converter control method for locomotives and rolling stock from a software control perspective include:

[0012] The single-phase vector current control used in this scheme belongs to the grid-following control architecture. Its control concept is based on the strong grid assumption and ignores the feedback effect of the converter on the grid. However, in railway grids with weak power supply conditions, the high impedance, low short-circuit ratio, and drastic load power changes make the four-quadrant rectifier under grid-following control prone to generating negative impedance effects, leading to instability in the "vehicle-grid" system.

[0013] This solution is mainly used in scenarios such as grid connection of new energy power generation, and its application in railway scenarios is relatively limited. Since the four-quadrant converter is the front-end equipment of traction, it must maintain the stability of the DC link in the traction system. However, the traditional single-loop DVSC control has a stability margin of less than 0 in the constant power scenario of traction, and cannot maintain the stability of DC voltage and system. Summary of the Invention

[0014] This invention provides a control method for a high-speed train four-quadrant rectifier by introducing frequency-added damping, so as to achieve stable operation of the high-speed train four-quadrant rectifier under weak power supply conditions.

[0015] To achieve the above objectives, the present invention adopts the following technical solution.

[0016] A control method for a high-speed train four-quadrant rectifier incorporating frequency-added damping combines a railway traction four-quadrant rectifier with a voltage source controller to form a novel high-speed railway traction four-quadrant rectifier. The railway traction four-quadrant rectifier includes a traction transformer, a high-speed train four-quadrant rectifier, a DC support capacitor, an inverter, and a motor. The voltage source controller includes an inner control loop and an outer control loop. The inner control loop comprises virtual admittance control and current control. The outer control loop includes a DC voltage synchronization control damping impedance controller with added VqFF damping, a current controller, a power calculation module, a reactive power control module, a coordinate transformation module, and DC voltage synchronization control with added VqFF damping. The method includes:

[0017] Sensors in the traction transformer collect real-time voltage data at the connection points between the locomotive / rolling vehicle and the traction network. RMS value of total line current DC bus voltage on the DC side ;

[0018] The power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the power of a single-phase voltage. and current The data is processed to calculate the instantaneous reactive power Q and active power P on the grid side.

[0019] The reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. ;

[0020] Adding V to the outer control loop of a voltage source controller q The DC voltage synchronization controller for the FF damper is based on the DC bus voltage on the DC side. Calculate the DC bus voltage deviation, and generate the fundamental angular frequency deviation based on the DC bus voltage deviation using a PI proportional-integral controller. Voltage at traction network connection points The frequency damping component is obtained by performing the Park transform. , power frequency angular frequency Basic deviation and damping component The superposition yields a synchronous phase angle with damping characteristics. ;

[0021] The outer control loop of a voltage source controller uses the generated amplitude signal and phase Reference voltage vector of the synthetic control inner loop The control inner loop in a voltage source controller is based on the reference voltage vector. The reference current command is calculated based on the preset virtual admittance model. Reference current command and the effective value of the total line current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train.

[0022] Preferably, the sensors in the traction transformer collect the voltage at the connection point between the locomotive / rolling vehicle and the traction network in real time. RMS value of total line current DC bus voltage on the DC side ,include:

[0023] Sensors in the traction transformer monitor the voltage at the connection point between the locomotive / rolling car and the traction network in real time. and the effective value of the total line current , voltage and the effective value of the total line current The voltage is stepped down to a level suitable for the operation of the four-quadrant converter in locomotives and rolling stock. The DC-side voltage sensor also collects the DC bus voltage on the DC side. The traction transformer will process the voltage signal. RMS value of total line current and DC bus voltage Transmitted to the voltage source controller.

[0024] Preferably, the power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the single-phase voltage. and current The process involves calculating the instantaneous reactive power Q and active power P on the grid side, including:

[0025] The power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the power of a single-phase voltage. and current The process is performed to calculate the voltage quadrature component that has the same amplitude as the input signal but lags behind it by 90 degrees. , ) and the orthogonal component of current ( , ), The original signal, As a lagging signal, a virtual two-phase stationary phase is constructed. Using a coordinate system, the instantaneous reactive power Q and active power P on the grid side are calculated using orthogonal components based on instantaneous power theory.

[0026] Preferably, the reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. ,include:

[0027] The reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. The potential amplitude reference signal It serves as the amplitude reference for the inner loop synthesis in a voltage source controller.

[0028]

[0029] : The reference signal for the amplitude of the output internal potential; : Rated no-load voltage amplitude of the four-quadrant rectifier; Reactive power-voltage droop coefficient; : Actual measured reactive power on the grid side; : Reactive power setpoint.

[0030] Preferably, V is added to the outer control loop of the voltage source controller. q The DC voltage synchronization controller for the FF damper is based on the DC bus voltage on the DC side. Calculate the DC bus voltage deviation, and generate the fundamental angular frequency deviation based on the DC bus voltage deviation using a PI proportional-integral controller. Voltage at traction network connection points The frequency damping component is obtained by performing the Park transform. , power frequency angular frequency Basic deviation and damping component The superposition yields a synchronous phase angle with damping characteristics. ,include:

[0031] Adding V to the outer control loop of a voltage source controller q The DC voltage synchronous control controller of the FF damper calculates the DC bus voltage deviation. ,according to The fundamental angular frequency deviation is generated using a PI controller. , The target value of the DC voltage set in the controller;

[0032] The VqFF damper uses the quadrature components of the voltage output from the second-order generalized integrator. and Perform Parker transformation to extract the q-axis voltage component in the synchronous rotating coordinate system. ;

[0033]

[0034] Will Multiply by the preset feedforward damping coefficient to obtain the frequency damping component. ;

[0035] power frequency angular frequency Basic deviation and damping component The synchronization angular frequency is obtained by superposition. For synchronization angular frequency Perform integration to generate the current synchronization phase angle. .

[0036] Preferably, the control inner loop in the voltage source controller is based on the potential amplitude reference signal. and synchronization phase The reference current command is calculated based on the preset virtual admittance model. Reference current command and the effective value of the total line current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train, including:

[0037] The control inner loop in a voltage source controller is based on the potential amplitude reference signal. and synchronization phase Internal potential reference vector of the four-quadrant converter of the composite locomotive and rolling stock ;

[0038] Control inner loop calculates internal potential reference With PCC point voltage The difference between them is used to calculate the reference current command based on a preset virtual admittance model. ;

[0039]

[0040] Virtual resistance; Virtual inductance;

[0041] Control inner loop to reference current command and actual current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train.

[0042] As can be seen from the technical solutions provided by the embodiments of the present invention described above, the present invention, by adopting a voltage source control mode scheme, enables the four-quadrant converter of the vehicle traction system to adapt to the high impedance characteristics of the railway traction power supply system, manifesting its external characteristics as a voltage source, and autonomously constructing voltage and frequency, thus solving the steady-state operation problem under the constant power characteristics of railways. The present invention improves the control structure of the single-loop DC-Link Voltage Synchronization Control (DVSC) by adding a q-axis voltage frequency feedforward (VqFF) damper. This improvement ensures steady-state operation under the constant power characteristics required for traction.

[0043] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a structural diagram of a railway traction four-quadrant rectifier provided in an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of a novel high-speed train locomotive four-quadrant rectifier, which combines a railway traction four-quadrant rectifier with a voltage source controller, is provided for an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of a control loop for generating orthogonal components required by a single-phase system, provided in an embodiment of the present invention.

[0048] Figure 4 An embodiment of this application provides a method for adding V q Detailed control structure block diagram after the FF damper;

[0049] Figure 5 This is a flowchart illustrating a control method for a four-quadrant rectifier of a high-speed train under weak power supply conditions, as described in an embodiment of this application.

[0050] Figure 6 For the traditional single-loop DVSC and DVSC+V under constant power scenarios obtained through experiments q Comparison of FF effects. Detailed Implementation

[0051] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0052] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0053] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0054] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0055] This invention, based on a novel voltage source control method, enhances system stability from the outset. By adding a VqFF damper to the voltage source control loop for constant power scenarios in railway traction, it improves the single-loop DVSC control structure. This improvement ensures steady-state operation under the constant power characteristics required for traction.

[0056] This invention proposes a voltage source control method for railway power grids with weak power supply conditions. The proposed method no longer relies on the grid voltage as a reference, but instead enables the four-quadrant rectifier to actively construct a voltage source, improving the system's adaptability to weak grids and fundamentally enhancing the system's dynamic stability.

[0057] The present invention provides a method for controlling a voltage source type four-quadrant rectifier of a high-speed train under weak power supply conditions by introducing frequency-added damping. The main body of this method is a railway traction four-quadrant rectifier, the structure of which is as follows: Figure 1 As shown in the figure. 101 is the traction transformer, 102 is the four-quadrant rectifier, 103 is the DC support capacitor, 104 is the inverter, and 105 is the motor.

[0058] 1. Traction transformer (101), used to collect the voltage of the locomotive and rolling stock at the connection point (PCC point) of the traction network in real time through sensors. and the effective value of the total line current .

[0059] 2. The four-quadrant converter (102) of the locomotive and rolling stock, as the core component of AC / DC conversion, is responsible for converting the secondary AC voltage and secondary current output by the traction transformer (101) into a stable DC voltage, and has the ability to flow energy in both directions (rectification in traction mode and feedback in braking mode). It is controlled by an internal controller.

[0060] 3. DC support capacitor (103): Connected in parallel between the four-quadrant converter and the inverter of the locomotive and rolling stock, it filters out the secondary ripple voltage and high-frequency switching harmonics of the converter output, stabilizes the DC bus voltage, and realizes power decoupling between the rectifier side and the inverter side.

[0061] 4. Inverter (104); Function: As a DC / AC conversion component, it is responsible for converting the constant DC power on the DC bus into three-phase AC power with adjustable frequency and amplitude to drive the traction motor.

[0062] 5. Motor (105): As the terminal execution component for electromechanical energy conversion (usually a three-phase asynchronous motor or permanent magnet synchronous motor), it is responsible for converting electrical energy into mechanical energy and driving the locomotive wheels to rotate.

[0063] The embodiments of the present invention will refer to the above. Figure 1 The railway traction four-quadrant rectifier shown is combined with a voltage source controller to form a... Figure 2 The new high-speed train locomotive four-quadrant rectifier shown in the figure has... Figure 2 The image above shows the control block diagram of a traditional railway traction four-quadrant rectifier. Figure 2 211 is a single-phase phase-locked loop, 212 is a coordinate transformation module, 213 is a digital controller, 214 is a reverse rotation transformation module, and 215 is an intermediate DC voltage controller.

[0064] Figure 2The figure below shows the voltage source controller proposed in this invention, which consists of two parts: an inner control loop and an outer control loop. The outer control loop is used to construct voltage and phase, while the inner control loop is for current control. In the figure, 211 is the damping impedance controller, 212 is the current controller, 213 is the power calculation module, 214 is the reactive power control module, 215 is the coordinate transformation module, and 216 is the module for adding V. q The DVSC (DC-Link Voltage Synchronization Control) controller for FF dampers.

[0065] Figure 3 The control loop is used to generate the orthogonal components required for the single-phase system. In the figure, 301 is a second-order generalized integrator used to construct the orthogonal components required for coordinate transformation, and 302 is the coordinate transformation module.

[0066] Figure 4 The V introduced in this invention example to achieve constant power steady-state operation q The detailed control block diagram of the FF damper shows that 401 is the coordinate transformation module, 402 is the damping coefficient, 403 is the DC voltage controller, 404 is the integrator, and 405 is the remainder module used for phase angle generation.

[0067] based on Figure 2 The novel high-speed train locomotive four-quadrant rectifier shown in this invention, and the processing flow of a current control method for a voltage source-type locomotive four-quadrant converter under weak power supply conditions proposed in this embodiment of the invention, are as follows: Figure 5 As shown, the processing steps are as follows:

[0068] Step S10: The sensors in the traction transformer (101) monitor the voltage at the connection point (PCC point) between the locomotive / rolling vehicle and the traction network in real time. and the effective value of the total line current , voltage and the effective value of the total line current The voltage is stepped down to a level suitable for the operation of the four-quadrant converter in locomotives and rolling stock. Simultaneously, the DC-side voltage sensor also collects the DC bus voltage on the DC side. .

[0069] The processed voltage signal RMS value of total line current and DC bus voltage It is transmitted to the voltage source controller as the basic input signal for subsequent control steps.

[0070] Step S20: The power calculation module 213 in the control outer loop of the voltage source controller uses a second-order generalized integrator (SOGI) to calculate the single-phase voltage. and current The data is processed to calculate the instantaneous reactive power Q and active power P on the grid side.

[0071] Because the locomotive traction system is a single-phase system, three-phase coordinate transformation cannot be directly applied. The power calculation module 213 in the outer control loop of the voltage source controller uses a second-order generalized integrator (SOGI) to calculate the single-phase voltage. and current To process, that is Figure 3 The 301 process in the middle. SOGI constructs a voltage quadrature component with the same amplitude as the input signal but with a phase lag of 90 degrees ( , ) and the orthogonal component of current ( , ), The original signal, As a delayed signal, a virtual two-phase stationary coordinate system is constructed ( (Coordinate system). Then, based on instantaneous power theory, the instantaneous reactive power Q and active power P on the grid side are calculated using orthogonal components.

[0072] In a single-phase AC railway traction system, in order to calculate the instantaneous reactive power on the grid side using the instantaneous power algorithm... and active power First, a second-order generalized integrator is needed to process the acquired instantaneous grid-side voltage value. and instantaneous value of line current Processing is performed. The actual acquired signal is used as... The axis component is used to generate a virtual signal with a 90-degree hysteresis through an algorithm. The axis components ultimately yield the instantaneous active power P and instantaneous reactive power Q as follows:

[0073] :

[0074] :

[0075] Step S30: Voltage amplitude generation (outer loop amplitude control).

[0076] The reactive power control module 214 in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through the droop coefficient. The potential amplitude reference signal It serves as the amplitude reference for the inner loop synthesis in a voltage source controller.

[0077]

[0078] : The reference signal for the amplitude of the output internal potential; : Rated no-load voltage amplitude of the four-quadrant rectifier; Reactive power-voltage droop coefficient; : Actual measured reactive power on the grid side; : Reactive power setpoint.

[0079] Step 504: Phase generation based on VqFF damper (outer loop phase control).

[0080] 1. Fundamental frequency generation: Adding V to the outer control loop of the voltage source controller. q The DVSC controller 216 of the FF damper calculates the DC bus voltage deviation. ),according to The fundamental angular frequency deviation is generated by a PI (proportional-integral) controller. In order to maintain active power balance. The target value of the DC voltage set in the controller is typically 3300V for high-speed trains.

[0081] 2. VqFF Damping Injection: To address the instability caused by constant power loads in railways, this invention innovatively introduces a q-axis voltage frequency feedforward (VqFF) damper. The VqFF damper utilizes the phase of the previous moment... right Perform Park transformation to extract the q-axis voltage component in the synchronous rotating coordinate system. .Will Multiply by the preset feedforward damping coefficient to obtain the frequency damping component. .

[0082] The VqFF damper outputs a quadrature voltage component through a second-order generalized integrator (SOGI). and Perform Park transformation to extract the q-axis voltage component in the synchronous rotating coordinate system. .

[0083] .

[0084] Step 505: Internal potential synthesis and virtual admittance current control (inner loop control)

[0085] 1. Voltage source construction: The control inner loop in the voltage source controller is based on the potential amplitude reference signal. and phase Internal potential reference vector of the four-quadrant converter of the composite locomotive and rolling stock This signifies that the four-quadrant converter of the locomotive and rolling stock is controlled as an active voltage source.

[0086] 2. Virtual admittance function: To adjust the output impedance characteristics, the inner loop is used to calculate the internal potential reference. With PCC point voltage The difference between them is used to calculate the reference current command based on a preset virtual admittance model. .

[0087]

[0088] Virtual resistance; Virtual inductance;

[0089] Control inner loop to reference current command and actual current Closed-loop control is performed to generate PWM modulation signals to drive the power switching transistors (IGBTs) of the four-quadrant rectifier of the high-speed train.

[0090] Figure 6 The method adopted through experiments Figure 2 The actual DC voltage waveforms of the two control methods Figure 6 The waveform in the above figure corresponds to Figure 2 The control method shown in the diagram above, Figure 6 The waveform in the following figure corresponds to Figure 2 The following figure illustrates the method proposed in this example. The results show that... Figure 6 The DC voltage in the above diagram fluctuates greatly, indicating system instability. Figure 6 The DC voltage fluctuation in the diagram below is very small, and the system is stable, achieving excellent control.

[0091] In summary, the embodiments of the present invention propose a voltage source control mode, which is designed for railway networks with weak power supply conditions. This mode can improve the stability of the system. The voltage source control mode can autonomously construct voltage and frequency and also provide support for systems with weak power supply conditions.

[0092] This invention proposes adding a VqFF damper to a single-loop DVSC control system to adapt the voltage source control method to the constant power scenario of railways. Experiments have shown that this has achieved good control results.

[0093] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0094] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0095] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for apparatus or system embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The apparatus and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0096] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for a voltage source type four-quadrant rectifier of a high-speed train with frequency-added damping, characterized in that, A railway traction four-quadrant rectifier is combined with a voltage source controller. The railway traction four-quadrant rectifier includes a traction transformer, a high-speed train four-quadrant rectifier, a DC support capacitor, an inverter, and a motor. The voltage source controller includes an inner control loop and an outer control loop. The inner control loop consists of virtual admittance control and current control, while the outer control loop includes an additional V... q The method includes: DC voltage synchronization control with FF damping, power calculation module, reactive power control module, and coordinate transformation module. Sensors in the traction transformer collect real-time voltage data at the connection points between the locomotive / rolling vehicle and the traction network. RMS value of total line current DC bus voltage on the DC side ; The power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the power of a single-phase voltage. and current The data is processed to calculate the instantaneous reactive power Q and active power P on the grid side. The reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. ; Adding V to the outer control loop of a voltage source controller q The DC voltage synchronization controller for the FF damper is based on the DC bus voltage on the DC side. Calculate the DC bus voltage deviation, and generate the fundamental angular frequency deviation based on the DC bus voltage deviation using a PI proportional-integral controller. Voltage at traction network connection points The frequency damping component is obtained by performing the Park transform. , power frequency angular frequency Basic deviation and damping component The superposition yields a synchronous phase angle with damping characteristics. ; The outer control loop of a voltage source controller uses the generated amplitude signal and phase Reference voltage vector of the synthetic control inner loop The control inner loop in a voltage source controller is based on and The reference current command is calculated based on the preset virtual admittance model. Reference current command and the effective value of the total line current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train.

2. The method according to claim 1, characterized in that, The sensors in the traction transformer collect the voltage at the connection point between the locomotive / rolling vehicle and the traction network in real time. RMS value of total line current DC bus voltage on the DC side ,include: Sensors in the traction transformer monitor the voltage at the connection point between the locomotive / rolling car and the traction network in real time. and the effective value of the total line current , voltage and the effective value of the total line current The voltage is stepped down to a level suitable for the operation of the four-quadrant converter in locomotives and rolling stock. The DC-side voltage sensor also collects the DC bus voltage on the DC side. The traction transformer will process the voltage signal. RMS value of total line current and DC bus voltage Transmitted to the voltage source controller.

3. The method according to claim 2, characterized in that, The power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the power of a single-phase voltage. and current The process involves calculating the instantaneous reactive power Q and active power P on the grid side, including: The power calculation module in the outer control loop of the voltage source controller uses a second-order generalized integrator to calculate the power of a single-phase voltage. and current The process is performed to calculate the voltage quadrature component that has the same amplitude as the input signal but lags behind it by 90 degrees. , ) and the orthogonal component of current ( , ), The original signal, As a lagging signal, a virtual two-phase stationary phase is constructed. Using a coordinate system, the instantaneous reactive power Q and active power P on the grid side are calculated using orthogonal components based on instantaneous power theory.

4. The method according to claim 3, characterized in that, The reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. ,include: The reactive power control module in the outer control loop of the voltage source controller compares the instantaneous reactive power Q with the reference reactive power, and generates a reference signal for the potential amplitude within the four-quadrant converter of the locomotive and rolling stock through a droop coefficient. The potential amplitude reference signal As the amplitude reference for inner-loop synthesis in a voltage source controller; : The reference signal for the amplitude of the output internal potential; : Rated no-load voltage amplitude of the four-quadrant rectifier; Reactive power-voltage droop coefficient; : Actual measured reactive power on the grid side; : Reactive power setpoint.

5. The method according to claim 4, characterized in that, The voltage source controller's outer control loop includes the addition of V q The DC voltage synchronization controller for the FF damper is based on the DC bus voltage on the DC side. Calculate the DC bus voltage deviation, and generate the fundamental angular frequency deviation based on the DC bus voltage deviation using a PI proportional-integral controller. Voltage at traction network connection points The frequency damping component is obtained by performing the Park transform. , power frequency angular frequency Basic deviation and damping component The superposition yields a synchronous phase angle with damping characteristics. ,include: Adding V to the outer control loop of a voltage source controller q The DVSC controller of the FF damper calculates the DC bus voltage deviation. ,according to The fundamental angular frequency deviation is generated using a PI controller. , The target value of the DC voltage set in the controller; The VqFF damper uses the quadrature components of the voltage output from the second-order generalized integrator. and Perform Parker transformation to extract the q-axis voltage component in the synchronous rotating coordinate system. ; Will Multiply by the preset feedforward damping coefficient to obtain the frequency damping component. ; power frequency angular frequency Basic deviation and damping component The synchronization angular frequency is obtained by superposition. For synchronization angular frequency Perform integration to generate the current synchronization phase angle. .

6. The method according to claim 5, characterized in that, The outer control loop of the voltage source controller generates an amplitude signal. and phase Reference voltage vector of the synthetic control inner loop The control inner loop in a voltage source controller is based on and The reference current command is calculated based on the preset virtual admittance model. Reference current command and the effective value of the total line current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train, including: The control inner loop in a voltage source controller is based on the potential amplitude reference signal. and synchronization phase Internal potential reference vector of the four-quadrant converter of the composite locomotive and rolling stock ; Control inner loop calculates internal potential reference With PCC point voltage The difference between them is used to calculate the reference current command based on a preset virtual admittance model. ; Virtual resistance; Virtual inductance; Control inner loop to reference current command and actual current Closed-loop control is performed to generate PWM modulation signals that drive the power switching transistors of the four-quadrant rectifier of the high-speed train.

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