Mixed voltage compensation power flow adjusting method and device based on IGBT-H bridge thyristor

Abstract

The invention discloses a mixed voltage compensation power flow adjusting method and device based on an IGBT-H bridge thyristor, and relates to the technical field of power electronic equipment, and the method comprises the following steps: adjusting the power through a preset discrete layer based on dynamic voltage tracking and shortest path optimization, and adjusting the power through a preset discrete layer; the shortest path is obtained by iterating an obtained local optimal path working point through a greedy algorithm; a series connection structure of a discrete layer and a preset continuous layer is constructed, in the structure, the discrete layer and the continuous layer are controlled to work cooperatively through a time sequence, and the cooperation comprises compensating for an error of power adjustment of the discrete layer through the continuous layer. The method is used for solving the problem that a hybrid phase-shifting transformer controlled by a thyristor has errors in power flow regulation.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic equipment, and more particularly to a hybrid voltage compensation power flow regulation method and device based on IGBT-H bridge thyristors. Background Art

[0002] In power systems, thyristor-controlled hybrid phase-shifting transformers are widely used for power flow regulation. They achieve efficient transmission and distribution of electrical energy through precise control of voltage and current. Traditional phase-shifting transformer control methods rely on stable power regulation technology. In particular, the accuracy and error of power flow regulation have become key factors restricting the efficient operation of distribution networks.

[0003] IGBT-H-bridge power electronic devices based on IGBT technology are gaining widespread application, offering significant advantages in efficient energy conversion, rapid response, and low losses. These devices can improve grid stability and adaptability, particularly under complex loads or variable grid conditions. Traditional thyristor-controlled high-voltage switches, with their low cost and high reliability, are widely used for power flow regulation in distribution networks.

[0004] The existing technology has at least the following problems: The control logic of TCHTs (thyristor-controlled hybrid phase-shifting transformers) has inherent limitations, making it difficult to achieve continuous and precise adjustment of the triggering moment and duration of their switching actions. This results in millisecond-level response delays and regulation errors exceeding millivolts in application scenarios such as power flow distribution and voltage compensation. This precision deficiency is particularly prominent in distribution networks with a high proportion of renewable energy access. When wind power or photovoltaic power output suddenly changes, the TCHT cannot promptly compensate for the voltage deviation caused by the power fluctuation, which may trigger the misoperation of protective devices and even, in severe cases, cause the renewable energy unit to disconnect from the grid.

[0005] In view of the above problems, the present invention proposes a solution. Summary of the Invention

[0006] To overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a hybrid voltage-compensated power flow regulation method and device based on IGBT-H-bridge thyristors. By dynamically tracking voltage, optimizing the shortest path, and coordinating timing to construct discrete and continuous layers for power error compensation, the problem of TCHT errors in power flow regulation is solved.

[0007] To achieve the above object, the present invention provides the following technical solutions: A hybrid voltage-compensated power flow regulation method based on IGBT-H-bridge thyristors comprises the following steps: regulating power through a preset discrete layer based on dynamic voltage tracking and shortest path optimization, wherein the shortest path is obtained by iteratively obtaining a local optimal path operating point through a greedy algorithm; and constructing a series structure of discrete layers and preset continuous layers. In this structure, the discrete layers and the continuous layers work in coordination through timing control, wherein the coordination includes compensating for errors in power regulation by the discrete layers through the continuous layers.

[0008] In a preferred embodiment, the discrete layer and continuous layer structure is constructed, the discrete layer structure includes: a valve control unit composed of thyristors, capacitors, inductors and a hybrid phase-shifting transformer; the continuous layer structure is composed of several IGBT-H bridge circuits, the specific structure is as follows Figure 3 shown.

[0009] In a preferred embodiment, the dynamic voltage tracking process is specifically as follows: inputting the voltage difference between the first power grid system and the second power grid system into a preset three-phase positive sequence coordinate axis; performing voltage difference vector decomposition on the voltage difference between any two phases in the coordinate axis to obtain a three-phase compensation gear; controlling the dynamic compensation voltage of the IGBT-H bridge thyristor according to the three-phase compensation gear. The dynamic voltage tracking process is as follows: Figure 4 shown.

[0010] In a preferred embodiment, the shortest path optimization and power control are constructed as follows: using a regular hexagonal compensation voltage vector diagram to narrow the voltage adjustment range and obtain the power value; obtaining the local optimal path working point based on the relationship between voltage-phase and power; using a greedy algorithm, iterating the local optimal path working point multiple times until the power error value is minimized, and determining the optimal path point.

[0011] In a preferred embodiment, the timing control coordinates the discrete layer and the continuous layer, specifically: performing primary power flow regulation through the discrete layer, and locking the IGBT-H bridge of the continuous compensation layer until the power flow is stable, and performing secondary power flow regulation through the continuous compensation layer.

[0012] In a preferred embodiment, the compensation process of the continuous layer power regulation error is specifically as follows: the output signal of the previous discrete layer is used as the input reference signal of the IGBT-H bridge continuous layer; the reference signal is combined with a proportional-integral controller to control the output signal of the IGBT-H bridge by adjusting the voltage and current to compensate for the power error generated by the discrete layer; the on and off of the IGBT is controlled by a PWM modulation signal, thereby compensating for the error in the discrete layer power regulation and improving the power flow regulation accuracy; the drive signal is generated by the amplitude of the PWM modulation signal to control the on and off combination of the IGBT-H bridge to compensate for the current and power of the four quadrants.

[0013] A hybrid voltage-compensated power flow regulation device based on IGBT-H bridge thyristors is characterized by comprising a discrete layer module, a compensation coordination module, and a control timing coordination module; the discrete layer module performs power regulation based on dynamic voltage tracking and shortest path optimization; the continuous layer module is used to be connected in series with the discrete layer to compensate for the error in the discrete layer power regulation; the compensation coordination module is used for the discrete layer to perform power regulation, and the continuous layer to compensate for the discrete layer power regulation error; the control timing coordination module is used for performing primary power flow regulation through the discrete layer, shutting down the IGBT-H bridge of the continuous layer until the power flow is stable, and performing secondary power flow regulation through the continuous layer.

[0014] The technical effects and advantages of the hybrid voltage compensation power flow regulation method and device based on IGBT-H bridge thyristors of the present invention are as follows: The present invention constructs a discrete layer to perform power regulation based on dynamic voltage tracking and shortest path optimization, and combines it with the continuous layer of the IGBT-H bridge to compensate for the power regulation error of the discrete layer. While retaining the economic advantages of TCHT, it is used to solve the problem of errors in TCHT power flow regulation, providing technical support for flexible loop closure of distribution networks and new energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flow chart of a hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristors provided in an embodiment of the present invention.

[0016] Figure 2 A schematic structural diagram of a hybrid voltage compensation power flow regulation device based on IGBT-H bridge thyristors provided in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the structure of the IGBT-H bridge series thyristors provided in an embodiment of the present invention.

[0018] Figure 4 A schematic diagram of the flow of dynamic voltage tracking control provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1, Figure 1 The present invention provides a hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristors, comprising the following steps: S1, based on dynamic voltage tracking and shortest path optimization, adjusts power through preset discrete layers. The shortest path is obtained by iteratively obtaining the local optimal path operating point through a greedy algorithm; S2, constructing a series structure of discrete layers and preset continuous layers, in which the discrete layers and the continuous layers work in coordination through timing control, wherein the coordination includes compensating the power regulation error of the discrete layers through the continuous layers.

[0021] This embodiment regulates power through discrete layers based on dynamic voltage tracking and shortest path optimization, combined with the continuous layers of IGBT-H bridges to achieve fast response and high precision. The core innovation lies in utilizing a hybrid control architecture of discrete and continuous layers. By constructing a discrete layer that regulates power based on dynamic voltage tracking and shortest path optimization, the power flow voltage deviation is reduced. Furthermore, by constructing a continuous layer based on IGBT-H bridges, real-time dynamic compensation of voltage and current is performed on the basis of discrete layer regulation, thus solving the problem of TCHT errors in power flow regulation.

[0022] S1, based on dynamic voltage tracking and shortest path optimization, adjusts power through preset discrete layers. The shortest path is obtained by iterating the local optimal path working point obtained by the greedy algorithm.

[0023] In this embodiment, the process of dynamic voltage tracking is as follows: Inputting the difference between the voltages at the first and second power grid system ports into a preset three-phase positive sequence coordinate axis; Perform voltage difference vector decomposition on any two-phase voltage difference in the coordinate axis to obtain the three-phase compensation gear; According to the three-phase compensation gear, the IGBT-H bridge thyristor compensation dynamic voltage is controlled.

[0024] It should be noted that the dynamic voltage tracking process is as follows Figure 4 As shown, when the voltage difference is decomposed on the positive sequence coordinate axes of the three phases A, B, and C, any two phases are first selected for decomposition. Phases A and B with voltage components select the voltage compensation gear closest to each other, and phase C without voltage components takes gear 0 to obtain the final three-phase compensation gear.

[0025] It should be noted that the output voltage difference , and its calculation formula is:

[0026] In the formula is the voltage value of the first input terminal, is the voltage value of the second input terminal.

[0027] It should be noted that the voltage difference vector decomposition of the voltage difference between any two phases is performed as follows:

[0028] Where, 、 、 are the voltage components on phases A, B, and C respectively, is the voltage phase difference between the grid system 1 and the grid system 2.

[0029] In this embodiment, the process of finding the shortest path is as follows: Use the regular hexagonal compensation voltage vector diagram to narrow the voltage regulation range and obtain the power value; According to the relationship between voltage-phase and power, the local optimal path operating point is obtained; The greedy algorithm is used to iterate the local optimal path working point multiple times until the power error value reaches the minimum and the optimal path point is determined.

[0030] It should be noted that the regular hexagonal compensation voltage vector diagram can unitize the voltage adjustable area, thereby calculating the difference between the actual active power and the reference active power and the difference between the actual reactive power and the reference reactive power.

[0031] It should be noted that the optimal path point refers to a unit where the error values ​​between the active power and reactive power and the reference power are minimized.

[0032] In this embodiment, the greedy algorithm is used to iterate the local optimal solution multiple times. The specific formula is: Active power relationship: (1) Reactive power relationship: (2) In the formula is the active power, is the reactive power, represents voltage, represents capacitance; Active power error: (3) Reactive error: (4) Comprehensive error: (5) Where α and β are weight coefficients; unit Active power: (6) unit Reactive power: (7) Where, is the system side voltage, is the compensation voltage amplitude of unit i, To compensate for the phase difference; 1. Based on the TCHT regular hexagonal compensation voltage vector diagram, the voltage adjustable range is divided into discrete gears, and the phase is divided into n intervals at 60° intervals or smaller intervals, forming m×n units; 2. Calculate the current power error. Calculate the current actual useful power according to the real-time monitoring data of the system. , useless work , combined with the reference value 、 , use formula (3) (4) (5) to calculate the current comprehensive error ; 3. Local optimal unit selection: Among the adjacent units of the current unit (adjacent vertices or adjacent interval units in a regular hexagon), use formulas (6) and (7) to calculate the optimal unit of each candidate unit. 、 , and then use formula (5) to calculate the comprehensive error ,choose The smallest unit serves as the “local optimal next step”; 4. Iterative optimization: Take the selected local optimal unit as the new current unit and repeat step 3 until: the comprehensive error ≤ ( is the set threshold), reaching the maximum number of iterations; 5. Determine the optimal working point: the unit that finally meets the error threshold corresponds to ( ,) is the optimal working point, and its corresponding 、 This is the target power that approaches the reference value.

[0033] S2, constructing a series structure of discrete layers and preset continuous layers, in which the discrete layers and the continuous layers work in coordination through timing control, wherein the coordination includes compensating the power regulation error of the discrete layers through the continuous layers.

[0034] In this embodiment, the process of adjusting the power error in the successive layers is specifically as follows: The output signal of the discrete layer is used as the input reference signal of the continuous layer; The reference signal is combined with a proportional-integral controller to control the output signal of the IGBT-H bridge by adjusting the voltage and current to compensate for the power error generated by the discrete layer; The on-off of the IGBT is controlled by PWM modulation signal, the output power is adjusted, and the power error of the discrete layer is compensated; The on and off of the IGBT-H bridge is controlled by PWM modulation signals, the amplitude and direction of voltage and current are changed, and the four-quadrant current and power are compensated.

[0035] It should be noted that the proportional-integral controller consists of two parts: proportional and integral: Proportional part: proportional to the current error. Proportional control responds quickly according to the size of the error to reduce the error; Integral part: proportional to the accumulated amount of error, the integral action can eliminate the steady-state error and ensure the ultimate stability of the system; In the above process, the proportional-integral controller adjusts the output power of the IGBT-H bridge to accurately track the reference signal, and achieves precise power regulation through a double closed loop, thereby compensating for the power error of the discrete layer output.

[0036] It should be noted that the control equation of the proportional-integral controller is:

[0037] Where, for The voltage reference value after control, is the actual power, is the power reference value, for The gain factor of the control, for The integral coefficient of the control, is the Laplace operator.

[0038] It should be noted that the PWM modulation signal controls the on and off of the IGBT-H bridge by allowing each phase to independently generate a drive signal through PWM modulation.

[0039] It should be noted that the voltage and current dual closed-loop control output signal, the specific formula for voltage regulation is:

[0040] Where, 、 、 are the line voltages before three-phase compensation, 、 、 are the line voltages after three-phase compensation, 、 、 are the output voltages of the hybrid phase-shifting transformer controlled by three-phase thyristors, 、 、 (i=1, 2, 3) are the voltages output from the 9 valve control units on the secondary side to the series transformer, 、 、 They are the compensation voltages of the three-phase IGBT-H bridge modules respectively.

[0041] Figure 3 The topology of the IGBT-H bridge connected in series with thyristors is given. The main units in the figure include: modular valve control unit, hybrid phase-shifting transformer, IGBT-H bridge module, and LC filter.

[0042] Each sub-unit of the modular valve control unit contains power electronic switches and capacitors and inductors. During execution, the reactive power compensation and impedance characteristics of the circuit are changed by group switching to achieve power flow distribution under different topologies. The hybrid phase-shifting transformer is mainly composed of a primary-side burning group connected to the distribution network bus, multiple secondary-side burning groups connected to the commutation sub-units, and a magnetic core for achieving electromagnetic coupling; By controlling the switching of the commutation sub-units through thyristors, the equivalent turns of the secondary side are changed, and the phase and amplitude of the output voltage are adjusted; The IGBT-H bridge module controls the on / off of the switch tube through PWM high-frequency modulation, adjusts the charging and discharging of the capacitor in real time, and accurately compensates for the millivolt-level voltage deviation that has not been eliminated in the discrete layer; LC filters effectively suppress harmonics generated by IGBT power electronic devices.

[0043] In this embodiment, the formula for suppressing harmonics generated by the IGBT power electronic device is:

[0044] In the formula for The filter's cutoff frequency, represents inductance, Represents capacitance.

[0045] Example 2, Figure 2 The present invention provides a hybrid voltage compensation power flow regulation device based on IGBT-H bridge thyristors, comprising a discrete layer module, a compensation coordination module, and a control timing coordination module; Discrete layer module, which performs power regulation based on dynamic voltage tracking and shortest path optimization; The continuous layer module is connected in series with the discrete layer to compensate for the error in regulating power of the discrete layer; In the compensation coordination module, the discrete layer performs power regulation, and the continuous layer compensates for the power regulation error of the discrete layer; The control timing coordination module performs primary power flow regulation through the discrete layer, closes the IGBT-H bridge of the continuous layer until the power flow is stable, and performs secondary power flow regulation through the continuous layer.

[0046] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formulas are set by technicians in this field according to actual conditions.

[0047] The above embodiments may be implemented in whole or in part through software, hardware, firmware or any other combination. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0048] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0049] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0050] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

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

Claims

1. A hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor, characterized in that: The following steps are involved: Power is regulated through preset discrete layers based on dynamic voltage tracking and shortest path optimization, where the shortest path is iterated by a greedy algorithm on the locally optimal path operating point. A series structure of discrete layers and preset continuous layers is constructed, in which the discrete layers and the continuous layers work in coordination through timing control, wherein the coordination includes compensating the power regulation error of the discrete layers through the continuous layers.

2. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 1, characterized in that: The discrete layer includes a valve-controlled unit composed of thyristors, a capacitor, an inductor and a hybrid phase-shifting transformer, and the continuous layer includes a plurality of IGBT-H bridge circuits.

3. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 2, characterized in that: The process of dynamic voltage tracking is as follows: Inputting the difference between the voltages at the first and second power grid system ports into a preset three-phase positive sequence coordinate axis; Perform voltage difference vector decomposition on any two-phase voltage difference in the coordinate axis to obtain the three-phase compensation gear; According to the three-phase compensation gear, the IGBT-H bridge thyristor compensation dynamic voltage is controlled.

4. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 3, characterized in that: The process of finding the shortest path is as follows: Use the regular hexagonal compensation voltage vector diagram to narrow the voltage regulation range and obtain the power value; According to the relationship between voltage-phase and power, the local optimal path operating point is obtained; The greedy algorithm is used to iterate the local optimal path working point multiple times until the power error value reaches the minimum and the optimal path point is determined.

5. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 4, characterized in that: The timing control coordinates the discrete layer and the continuous layer, specifically: Perform a power flow adjustment through the discrete layer and turn off the IGBT-H bridge of the continuous layer until the power flow stabilizes; Secondary power flow regulation is performed through successive layers.

6. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 5, characterized in that: The voltage difference vector decomposition, the specific formula is: Where, is the difference between the first and second power grid system port voltages, 、 、 are the voltage components on the three phases, is the phase difference between the port voltages of the first power grid system and the second power grid system.

7. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 6, characterized in that: The process of adjusting the power error in the continuous layer is specifically as follows: The output signal of the discrete layer is used as the input reference signal of the continuous layer; The reference signal is combined with a proportional-integral controller to control the output signal of the IGBT-H bridge by adjusting the voltage and current to compensate for the power error generated by the discrete layer; The on-off of the IGBT is controlled by PWM modulation signal, the output power is adjusted, and the power error of the discrete layer is compensated; The on and off of the IGBT-H bridge is controlled by PWM modulation signals, the amplitude and direction of voltage and current are changed, and the four-quadrant current and power are compensated.

8. The hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristor according to claim 7, characterized in that: The control equation of the proportional-integral controller is: Where, for The voltage reference value after control, is the actual power, is the power reference value, for The gain factor of the control, for The integral coefficient of the control, is the Laplace operator.

9. A device using the hybrid voltage compensation power flow regulation method based on IGBT-H bridge thyristors according to any one of claims 1 to 8, characterized in that: It includes discrete layer module, continuous layer module, compensation coordination module and control timing coordination module; Discrete layer module, which performs power regulation based on dynamic voltage tracking and shortest path optimization; The continuous layer module is connected in series with the discrete layer to compensate for the error in regulating power of the discrete layer; In the compensation coordination module, the discrete layer performs power regulation, and the continuous layer compensates for the power regulation error of the discrete layer; The control timing coordination module performs primary power flow regulation through the discrete layer, closes the IGBT-H bridge of the continuous layer until the power flow is stable, and performs secondary power flow regulation through the continuous layer.

Images