A continuous control method for generator-driven main transformer zero-start voltage boost

Abstract

This invention discloses a continuous control method for generator-transformer zero-start voltage boosting, relating to the field of power system control technology. The method includes: after the generator output circuit breaker is closed, an automatic soft-start excitation program is triggered to smoothly raise the generator terminal voltage from 0 to a low initial set value; after the initial voltage is established, the excitation current is linearly increased at a preset voltage boosting rate to continuously raise the generator terminal voltage to the rated voltage; the generator terminal voltage is compared with the target voltage in real time, and the excitation current output is dynamically adjusted to suppress overshoot and oscillation; the excitation current output curve is automatically corrected according to the real-time generator speed and system frequency to ensure voltage-frequency synchronization. This invention's continuous control method for generator-transformer zero-start voltage boosting effectively eliminates voltage surges and excitation inrush currents, significantly reduces the risk of transformer insulation damage and protection malfunction rate, and achieves continuous, stable, and highly reliable control of the voltage boosting process.

Description

Technical Field

[0001] This invention relates to the field of power system control technology, and in particular to a continuous control method for generator-driven main transformer zero-start voltage boost. Background Technology

[0002] As a core piece of equipment in power systems, generators are widely used in hydropower plants for black starts and insulation testing after equipment maintenance. Related technologies utilize the coordinated operation of the excitation system and the main transformer to construct a control system that gradually increases voltage from zero to the rated value. Specifically, this technology covers the entire process from soft-start excitation initialization to continuous voltage increase at a preset rate, including key aspects such as excitation current slope control, closed-loop PID regulation, and speed-voltage feedforward compensation. With the development of smart grid technology, traditional step-by-step voltage increase methods are no longer sufficient to meet the stringent requirements of modern hydropower plants for equipment safety and control precision.

[0003] However, existing zero-start voltage boosting methods directly employ segmented voltage regulation strategies (such as 10%, 25%, and 50% rated voltage steps) and preset initial voltage values ​​(usually ≥10% of rated voltage). This can lead to a chain of problems such as equipment surges, inrush currents, and protection malfunctions. Specifically, the transient change ΔU>15% caused by step-up voltage boosting can easily cause cable burnout on the high-voltage side of the main transformer. Excessively high initial voltage can lead to core saturation, generating inrush currents of 5-10 times the rated current, which in turn threatens insulation performance. Based on this, the overvoltage protection malfunction rate in traditional schemes is >8%, requiring manual deactivation of the protection device to complete the voltage boost, which poses a risk of short-circuit spread. In particular, uneven manual operation rates and poor parameter matching further exacerbate voltage oscillations (>1 time) and reactive power back absorption (±30% fluctuation), resulting in a significantly increased voltage build-up failure rate. Summary of the Invention

[0004] The main objective of this invention is to provide a continuous control method for generator-driven main transformer zero-start voltage boost.

[0005] Another objective of this invention is to provide a continuous control device for generator-driven main transformer zero-start voltage boost.

[0006] The third objective of this invention is to provide a computer device.

[0007] A fourth objective of this invention is to provide a non-transitory computer-readable storage medium.

[0008] To achieve the above objectives, a first aspect of the present invention provides a continuous control method for generator-driven main transformer zero-start voltage boost, comprising:

[0009] S1, after the generator outlet circuit breaker is closed, the soft start excitation program is automatically triggered to smoothly raise the generator terminal voltage from 0 to the low initial set value. S2, after the initial voltage is established, the excitation current is increased linearly according to the preset voltage increase rate, so that the terminal voltage is continuously increased to the rated voltage; S3 compares the terminal voltage with the target voltage in real time and dynamically adjusts the excitation current output to suppress overshoot and oscillation; S4 automatically corrects the excitation current output curve based on the unit's real-time speed and system frequency to ensure voltage-frequency synchronization.

[0010] In one embodiment of the present invention, after the generator output circuit breaker is closed, a soft start-up program is automatically triggered to smoothly raise the generator terminal voltage from 0 to a low initial set value, and the method further includes: S11 uses a ramp function generator to control the excitation current and establishes the initial voltage with a constant slope; S12 limits the low initial setting value to 10% of the rated voltage to avoid inrush current caused by core saturation.

[0011] In one embodiment of the present invention, the step of linearly increasing the excitation current at a preset boost rate to continuously raise the terminal voltage to the rated voltage further includes: S21, preset boost rate for This ensures the continuity of voltage changes; S22, automatically adjusts the voltage boost rate according to the main transformer capacity. The range of values ​​is To meet the needs of different working conditions.

[0012] In one embodiment of the present invention, the real-time comparison of the terminal voltage with the target voltage, and the dynamic adjustment of the excitation current output to suppress overshoot and oscillation, further includes: S31 adjusts the excitation current in real time through a closed-loop PID controller. Make the terminal voltage With target voltage The deviation is less than 0.5%; S32, Target Voltage It is generated by a linear function, and its expression is:

[0013] in, For boost rate, For time, This is the initial setting value.

[0014] In one embodiment of the present invention, the step of automatically correcting the excitation current output curve based on the real-time speed of the unit and the system frequency to ensure voltage-frequency synchronization further includes: S41, uses a speed-voltage feedforward compensator to calculate the compensation amount. The formula for calculating the compensation amount is:

[0015] in, For compensation coefficient, Rated speed; S42, the response time of the feedforward compensator is less than... This offsets the impact of speed fluctuations on voltage-frequency synchronization.

[0016] In one embodiment of the present invention, it further includes: S5 automatically matches the boost rate according to the preset black start or maintenance test mode. and compensation coefficient It enables one-click trigger control under different working conditions.

[0017] To achieve the above objectives, a second aspect of the present invention provides a continuous control device for generator-driven main transformer zero-start voltage boost, comprising: The initial voltage establishment module is used to automatically trigger the soft start excitation program after the generator outlet circuit breaker is closed, so as to smoothly raise the generator terminal voltage from 0 to the low initial set value. The excitation current linear adjustment module is used to linearly increase the excitation current according to a preset voltage rise rate after the initial voltage is established, so that the terminal voltage can be continuously increased to the rated voltage. The voltage deviation dynamic compensation module is used to compare the terminal voltage with the target voltage in real time, dynamically adjust the excitation current output, and suppress overshoot and oscillation. The speed and frequency synchronization correction module is used to automatically correct the excitation current output curve based on the real-time speed of the unit and the system frequency, so as to ensure voltage-frequency synchronization.

[0018] To achieve the above objectives, a third aspect of this application provides a computer device, including a processor and a memory; wherein the processor runs a program corresponding to the executable program code by reading executable program code stored in the memory, for implementing a continuous control method for generator-driven main transformer zero-start voltage boost as described in the first aspect embodiment.

[0019] To achieve the above objectives, a fourth aspect of this application provides a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements a continuous control method for zero-start voltage boosting of a generator-driven main transformer as described in the first aspect embodiment.

[0020] The embodiments of the present invention have the following beneficial effects: The methods, apparatus, electronic devices, and computer-readable storage media of the present invention can effectively eliminate voltage surges and inrush currents, significantly reduce the risk of main transformer insulation damage and protection malfunction rate, and achieve continuous, stable, and highly reliable control of the voltage boosting process. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 A flowchart of a continuous control method for generator-driven main transformer zero-start voltage boost provided in an embodiment of the present invention; Figure 2 This is an architecture diagram of a continuous control method for generator-driven main transformer zero-start voltage boost provided by an embodiment of the present invention; Figure 3 This is a structural diagram of a continuous control device for generator-driven main transformer zero-start voltage boost provided in an embodiment of the present invention. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] The following describes a continuous control method and apparatus for generator-driven main transformer zero-start voltage boost according to an embodiment of the present invention, with reference to the accompanying drawings.

[0025] Example 1 This embodiment provides a continuous control method for generator-driven main transformer zero-start voltage boost. For example... Figure 1 and Figure 2 As shown, the method includes the following steps: S1: After the generator outlet circuit breaker is closed, the soft start excitation program is automatically triggered to smoothly raise the generator terminal voltage from 0 to the low initial set value.

[0026] Specifically, after the generator output circuit breaker (GCB) is closed, the system automatically triggers a soft-start excitation program to smoothly raise the generator terminal voltage from zero to a low initial set value. This is one of the key steps in the present invention to achieve generator-driven main transformer zero-start voltage rise control. This step achieves a smooth voltage rise by introducing a ramp function generator (RFG) to control the output of the excitation current, thereby effectively suppressing voltage surges and inrush currents, and improving the safety and stability of equipment operation.

[0027] In this embodiment of the invention, after the soft-start excitation program is initiated, the excitation system first gradually increases the excitation current at a constant slope. This makes the terminal voltage The voltage rises linearly from 0 to 10% of the rated voltage. During this phase, the system employs a closed-loop control strategy, acquiring the terminal voltage in real time. With target voltage The deviation is input to the PID controller to dynamically adjust the excitation current output, ensuring the smoothness and controllability of the voltage rise process.

[0028] Furthermore, the initial voltage during the soft-start stage is set to 10% of the rated voltage, and the voltage ramp rate is set to 0.5% / s. This rate can be adaptively adjusted within the range of 0.05% / s to 2% / s based on the transformer capacity. Simultaneously, the system requires voltage overshoot to be controlled within 2% and the number of oscillations to not exceed one, ensuring the stability of the excitation process. In addition, the peak value of the inrush current is reduced by more than 50% compared to traditional solutions, significantly mitigating electromagnetic shock to the transformer and cables.

[0029] This procedure is widely applicable to conditions such as black start in hydropower plants and insulation testing after main transformer maintenance. After the GCB is closed, the system automatically enters the soft excitation process without manual intervention, achieving a smooth transition from zero voltage to a low initial value, laying a stable foundation for the subsequent continuous voltage ramp-up phase.

[0030] The technical benefits of this step lie in its effective suppression of inrush current and core saturation through a soft-start mechanism, reducing the risk of transformer insulation damage. Simultaneously, the closed-loop control strategy ensures the stability of the voltage rise process, avoiding voltage oscillations and reactive power back absorption problems caused by uneven speeds or parameter mismatches. Overall, this step provides a safe, stable, and automated starting control method for generator-transformer zero-start voltage boost, serving as a crucial guarantee for achieving high-reliability system operation.

[0031] Furthermore, S1 includes: S11 uses a ramp function generator to control the excitation current and establishes the initial voltage with a constant slope.

[0032] Specifically, this invention uses a ramp function generator (RFG) to control the excitation current at a constant slope. Establishing the initial voltage is the core technical means to realize the soft start-up process. The technical principle of this step is based on linear control theory. By introducing a voltage reference signal with a preset slope into the excitation system, the generator terminal voltage is gradually increased from zero at a controllable rate, thereby effectively suppressing excitation inrush current and core saturation.

[0033] This step effectively reduces the risk of burnout of the high-voltage side cable of the main transformer due to excitation inrush current, and avoids maloperation of the excitation system protection caused by voltage surge, thereby significantly improving equipment safety and control stability.

[0034] S12 limits the low initial setting value to 10% of the rated voltage to avoid inrush current caused by core saturation.

[0035] Specifically, in some implementations, limiting the low initial setpoint to 10% of the rated voltage is one of the key control strategies in the generator-driven main transformer zero-start voltage boosting method of this invention. Its technical implementation is based on the soft-start excitation principle and the dynamic response characteristics of the excitation system. This step aims to control the initial output of the excitation current to achieve the desired generator output voltage (terminal voltage). Starting from zero, the voltage rises smoothly at a constant slope to 10% of the rated voltage. This effectively prevents the main transformer core from saturating due to a sudden change in magnetic flux at the moment of excitation, thereby suppressing the generation of inrush current.

[0036] In this embodiment of the invention, after the generator output circuit breaker is closed, the system automatically triggers a soft-start excitation program to generate a target voltage curve using a ramp function generator. This function gradually increases the excitation current at a constant rate. Thus control The initial setting is 10% of the rated voltage to ensure a low flux change rate in the initial stage of excitation, keeping the core magnetization curve in the linear region and avoiding a surge in inrush current due to magnetic saturation.

[0037] Furthermore, the initial voltage setting value in this step is... ,in This is the generator's rated voltage. The boost rate is controlled by RFG, with a typical value of [value missing]. It can be based on the main transformer capacity. It adaptively adjusts within a certain range. Furthermore, this step seamlessly connects with subsequent continuous voltage boosting at a preset rate, ensuring the continuity and stability of the entire voltage boosting process.

[0038] S2, after the initial voltage is established, the excitation current is increased linearly according to the preset voltage increase rate, so that the terminal voltage is continuously increased to the rated voltage.

[0039] Specifically, after completing the soft-start initialization, the present invention enters the linear boost stage. The core technical principle of this stage is to control the excitation current. The linear increase in voltage at the generator terminals causes the generator terminal voltage to... According to the preset rate The voltage is gradually and continuously increased from a low initial value to 100% of the rated voltage. This process employs a combination of a closed-loop PID controller and a feedforward compensation mechanism to achieve precise regulation of the excitation current, thereby ensuring the smoothness and controllability of the voltage rise process.

[0040] In this embodiment of the invention, firstly, according to the set boost rate... Generate the target voltage curve ,in, The initial voltage setpoint is set. Subsequently, the PID controller acquires the generator terminal voltage in real time. and with target voltage Compare and calculate the deviation And adjust the excitation current output accordingly. This enables closed-loop tracking control of the voltage. Furthermore, the system incorporates a speed-voltage feedforward compensation module, which adjusts the voltage based on the unit's real-time speed. With rated speed The deviation is calculated to determine the compensation amount. This further improves the coordination and response speed of voltage and frequency.

[0041] In practical applications, this step is suitable for scenarios such as black start in hydropower plants and insulation testing after main transformer maintenance. Under these conditions, continuous linear voltage boosting can effectively avoid problems such as inrush current, core saturation, and protection malfunctions caused by step voltage boosting. According to measured data, this invention controls voltage overshoot to <1.5% during the voltage boosting process, and reduces reactive power fluctuation range to [missing value]. Significantly better than the traditional approach's >5% and .

[0042] In summary, this step, by precisely controlling the linear growth of the excitation current and combining closed-loop PID regulation with a feedforward compensation mechanism, achieves a continuous and stable rise in the generator terminal voltage, providing a high level of safety, stability, and automation for the zero-start voltage boost of the generator-driven main transformer.

[0043] Furthermore, S2 includes: S21, preset boost rate for This ensures the continuity of voltage changes.

[0044] Specifically, in this invention, a preset boost rate is used. This is a key control parameter for achieving continuity and stability during the generator-driven main transformer zero-start voltage ramp-up process. The technical implementation of this step is based on the linear continuous voltage ramp-up stage after soft-start excitation initialization. It achieves control over the generator terminal voltage through the coordinated action of the ramp function generator and closed-loop PID controller in the excitation system. Precise control.

[0045] The technical benefits of this step are significant: firstly, continuous voltage boosting avoids equipment shocks and protection malfunctions caused by voltage surges in traditional step control; secondly, precise rate control improves the stability of the excitation system and the operational safety of the main transformer. Furthermore, this preset rate mechanism lays the foundation for subsequent automated control processes, ensuring high reliability and ease of operation throughout the entire voltage boosting process.

[0046] S22, automatically adjusts the voltage boost rate according to the main transformer capacity. The range of values ​​is To meet the needs of different working conditions.

[0047] Specifically, the voltage boost rate is automatically adjusted according to the main transformer capacity. The range of values ​​is This is one of the core control strategies for the preset rate continuous voltage boosting step in this invention. This step introduces a rate adaptive mechanism based on the main transformer capacity to achieve refined control of the generator-driven main transformer zero-start voltage boosting process, thereby matching the system response characteristics and equipment safety requirements under different operating conditions.

[0048] In this embodiment of the invention, this step relies on the rate regulation module in the excitation control system. After the initial voltage is established, this module adjusts the rate regulation according to the rated capacity of the main transformer. Dynamically calculate and set the boost rate Specifically, the system first reads the capacity parameters of the main transformer and then determines the rate mapping function (such as a linear or piecewise function) using a preset rate mapping function. The initial value. During the voltage boost process, the system continuously monitors the voltage response of the main transformer. With target voltage The deviation is adjusted by combining the PID controller to regulate the excitation current. To ensure that the voltage is at the set rate Linear ramp-up. This control method avoids the voltage surge and inrush current problems caused by traditional step-up voltage boosting.

[0049] Furthermore, the boost rate The range of values ​​is The minimum value Suitable for large-capacity main transformers (such as 800MVA) to reduce the risk of core saturation and inrush current; maximum value This is suitable for small-capacity main transformers (such as 50MVA) to improve boost efficiency.

[0050] This procedure is widely applicable to scenarios such as black start in hydropower plants and insulation testing after main transformer maintenance. In actual operation, the system monitors the main transformer capacity parameters and current operating conditions, automatically selects the optimal voltage boost rate, and achieves fully automated control with one-click triggering, significantly reducing manual intervention steps and improving operational efficiency and safety.

[0051] S3 compares the terminal voltage with the target voltage in real time, dynamically adjusts the excitation current output, and suppresses overshoot and oscillation.

[0052] Specifically, in this invention, step S3 is a crucial step in achieving stable zero-start voltage boost control of the generator-driven main transformer. This step, based on closed-loop control principles and combining a PID control algorithm with a feedforward compensation mechanism, achieves precise control of the excitation current, thereby ensuring the generator terminal voltage (…). It can follow the preset target voltage curve. It can rise smoothly and continuously, avoiding voltage surges, inrush currents, and oscillations caused by traditional step-up voltage boosting.

[0053] In this embodiment of the invention, the generator output voltage is first collected in real time using a voltage sensor. and the target voltage generated by the linear function. The comparison is performed. The comparison result serves as the input deviation signal for the PID controller. The controller dynamically adjusts the excitation current based on the weighted output of the proportional, integral, and derivative components. In order to achieve Closed-loop control. PID parameters can be self-tuned based on system response characteristics to adapt to different main transformer capacities (50MVA~800MVA) and unit speeds. The changes.

[0054] Furthermore, this step requires that the voltage deviation be controlled within <0.5%, the overshoot not exceed 1.5%, and the number of oscillations be controlled within [specific range]. Next, the system introduces a speed-voltage feedforward compensator to calculate the compensation amount. ,in For compensation coefficient, For the rated speed, the compensation response time must be less than [time value missing]. This allows for a rapid response to the impact of speed fluctuations on the excitation output.

[0055] Specifically, this step is widely used in situations such as black start in hydropower plants and insulation testing after main transformer maintenance. Through automated control, the system can complete the voltage boosting process from 0 to 100% of the rated voltage within 300 seconds after the GCB is closed, reducing the operation steps from 20 steps in the traditional scheme to 3 steps, significantly improving operational efficiency and safety.

[0056] The technical effect of this step is that, through the synergistic effect of real-time closed-loop regulation and feedforward compensation, voltage overshoot and oscillation are effectively suppressed, the reactive power fluctuation range is reduced, and reactive power back absorption is avoided, thereby improving system stability and equipment safety.

[0057] Furthermore, S3 includes: S31 adjusts the excitation current in real time through a closed-loop PID controller. Make the terminal voltage With target voltage The deviation is less than 0.5%.

[0058] Specifically, the present invention adjusts the excitation current in real time using a closed-loop PID controller. To ensure terminal voltage With target voltage The deviation is consistently controlled within 0.5%, which is the key technical means to achieve stable voltage control and stable system voltage build-up in this invention. This step is based on the feedback control principle and combines a PID algorithm to dynamically adjust the excitation current, thereby achieving high-precision closed-loop control of the generator terminal voltage.

[0059] In this embodiment of the invention, the generator output voltage is first collected in real time using a voltage sensor. and the target voltage generated by the linear function. By comparison, the voltage deviation signal is obtained. The deviation signal serves as the input to the PID controller, which dynamically adjusts the excitation current based on the weighted output of the proportional, integral, and derivative components. Specifically, the proportional element responds quickly to the current deviation, the integral element eliminates steady-state error, and the derivative element suppresses the rate of voltage change, thereby effectively suppressing overshoot and oscillation.

[0060] Specifically, this step is widely used in scenarios such as black start in hydropower plants and insulation testing after main transformer maintenance. Under these conditions, the generator needs to be gradually boosted from zero voltage to the rated value to verify the insulation performance and phase sequence correctness of the main transformer and its auxiliary equipment. Through closed-loop PID control, the system can automatically complete the voltage boosting process without frequent manual intervention, significantly improving operational safety and efficiency.

[0061] This step effectively suppresses voltage overshoot and oscillation, significantly outperforming traditional solutions. Simultaneously, by precisely controlling the excitation current, the system can reduce reactive power fluctuations from... Shrink to This avoids reactive power back absorption, thereby improving the stability and success rate of the excitation process. This technology provides a solid guarantee for achieving automated and highly reliable control of generator-driven main transformer zero-start voltage boost.

[0062] S32, Target Voltage It is generated by a linear function, and its expression is:

[0063] in, For boost rate, For time, This is the initial setting value.

[0064] Specifically, in the technical solution of the present invention, the target voltage The generation of [the generator] is one of the core components in realizing the generator-driven main transformer zero-start voltage boost control strategy. This step is achieved through a linear function, the expression of which is: ,in Indicates the boost rate (unit: % / s). This is a time variable (in seconds). The function is implemented by the system's built-in ramp function generator, used to gradually increase the target voltage at a preset constant rate after the initial voltage is established, thereby driving the excitation system to output the corresponding excitation current. This makes the generator terminal voltage It rose steadily to the rated value.

[0065] In this embodiment of the invention, the linear function is generated based on the closed-loop regulation mechanism of the excitation control system. The system first smoothly increases the terminal voltage from 0 to 10% of the rated voltage using a soft-start excitation program, and then enters a continuous voltage ramp-up phase. During this phase, the RFG operates according to the set voltage ramp-up rate. (Typical value is 0.05% / s, range can be adaptively adjusted from 0.05% / s to 2% / s to accommodate different main transformer capacities) Generate the target voltage curve. This curve serves as the reference input for the PID controller, along with the real-time measured terminal voltage. The actual voltage is compared, the deviation is calculated, and the excitation current output is dynamically adjusted to ensure that the actual voltage always tracks the target voltage curve.

[0066] S4 automatically corrects the excitation current output curve based on the unit's real-time speed and system frequency to ensure voltage-frequency synchronization.

[0067] Specifically, in step S4, the unit speed is monitored in real time. With system frequency The excitation current output curve is automatically corrected to achieve synchronous and coordinated control of voltage and frequency. This step is a key part of the entire zero-start voltage boost control strategy. Its technical implementation is based on a speed-voltage feedforward compensation mechanism, combined with the closed-loop regulation capability of the excitation system, thereby improving the stability and safety of the excitation process.

[0068] In this embodiment of the invention, this step involves adding a speed-voltage feedforward compensator to dynamically correct the excitation current output. Specifically, the system first acquires the current generator speed. With rated speed And calculate the compensation amount based on the deviation between the two. Its value needs to be calibrated according to the characteristics of the unit, usually in Adjustments are made within a specified range to ensure the sensitivity and stability of the compensation response. Compensation amount. As a feedforward signal superimposed on the excitation current control loop, the excitation output is adjusted in advance before the speed change causes voltage deviation, thus achieving dynamic voltage-frequency matching.

[0069] Furthermore, the compensation response time requirement is less than This ensures the system responds quickly to speed disturbances. Simultaneously, the compensation coefficient... The settings need to meet the excitation adjustment requirements under different operating conditions. For example, during black start or maintenance tests, the unit speed may be lower than the rated value, and in this case, it is necessary to appropriately increase the excitation speed. This is to accelerate voltage build-up while avoiding excitation current overshoot.

[0070] This procedure is widely applicable to scenarios such as black start in hydropower plants and insulation testing after main transformer maintenance. Under these conditions, the system frequency and unit speed may fluctuate asynchronously. This feedforward compensation mechanism can effectively suppress voltage instability caused by speed changes, thereby avoiding problems such as reactive power back absorption and voltage build-up failure.

[0071] Table 1 shows the comparative data of the measured performance of Unit #5 of Xiaowan Power Plant under the black start scenario. Through four core technical indicators, the performance differences between the traditional excitation control scheme and the scheme of the present invention are compared. The scheme of the present invention has achieved significant improvements in four dimensions: boost efficiency, voltage stability, equipment impact suppression, and ease of operation.

[0072] Table 1

[0073] This step offers significant technical benefits, with its core value lying in enhancing the dynamic response capability and system stability of the excitation control. By real-time correction of the excitation current output curve, the system can achieve synchronous coordination between voltage and frequency, ensuring the smoothness and controllability of the voltage boosting process, thereby improving equipment safety and control reliability.

[0074] Furthermore, S4 includes: S41, uses a speed-voltage feedforward compensator to calculate the compensation amount. The formula for calculating the compensation amount is:

[0075] in, For compensation coefficient, This is the rated speed.

[0076] Specifically, in the generator-driven main transformer zero-start voltage boosting method of the present invention, the introduction of a speed-voltage feedforward compensator is a key step in achieving dynamic response optimization of the excitation system and voltage control stability. This compensator monitors the generator speed in real time. With rated speed The deviation is used to calculate the corresponding voltage compensation amount. ,in This is a compensation coefficient used to quantify the impact of speed variations on the excitation current output. It demonstrates the innovation of this invention in speed-voltage coordinated control.

[0077] In this embodiment of the invention, the speed-voltage feedforward compensator is typically integrated into the control loop of the excitation regulator, operating in parallel with the PID closed-loop controller. Its core principle is based on the physical relationship between generator speed and terminal voltage: when the speed deviates from the rated value, the induced electromotive force of the generator changes, thus affecting the voltage output. Through the feedforward compensation mechanism, the system can adjust the excitation current output in advance before the speed change causes a voltage deviation, achieving a fast and accurate voltage response. Specifically, the speed signal is acquired by the unit's speed sensor, converted by an A / D converter, and then input to the compensator module, with the compensation amount... It is superimposed with the target excitation current to form the final excitation control signal.

[0078] Furthermore, the compensation coefficient Calibration is typically performed based on the unit's excitation characteristic curve to ensure that the compensation amount matches the actual voltage deviation within different speed ranges. Rated speed The speed is typically set to synchronous speed (e.g., 3000 r / min in a 50 Hz system), and the compensation response time is required to be less than 100 ms to meet the rapid adjustment requirements of the excitation system for dynamic processes.

[0079] In practical applications, this step is mainly used to address voltage control issues caused by grid frequency fluctuations or unstable generator speeds, and is particularly suitable for conditions requiring high stability during the excitation process, such as black starts and maintenance tests. Through speed feedforward compensation, the system can effectively suppress voltage oscillations and reactive power back absorption caused by speed disturbances, improve the voltage build-up success rate to 100%, and ensure the smoothness and safety of the voltage boosting process.

[0080] S42, the response time of the feedforward compensator is less than... This offsets the impact of speed fluctuations on voltage-frequency synchronization.

[0081] Specifically, the response time of the feedforward compensator of the present invention is less than [time value missing]. Its core function is to quickly offset the voltage-frequency synchronization deviation caused by generator speed fluctuations, thereby improving the dynamic response capability and system stability of excitation control. This step is based on the principle of speed-voltage coordinated control, and involves real-time monitoring of generator speed. With system frequency The excitation current output curve is dynamically corrected according to the changes in voltage to ensure that the voltage and frequency matching relationship is always within a reasonable range during the boost process.

[0082] In this embodiment of the invention, the feedforward compensator adopts an incremental compensation strategy, and its compensation amount... ,in For compensation coefficient, The rated speed is used. When the unit speed deviates from the rated value, the compensator immediately calculates the corresponding excitation current adjustment and adds it to the original PID closed-loop control output, realizing feedforward-feedback composite control of the excitation current. This compensation mechanism has strict requirements in the time dimension; its response time must be controlled within [timeframe missing]. Within this range, to ensure that the excitation system can make rapid adjustments when there are sudden changes in speed (such as in the early stages of black start or grid disturbances), and to avoid reactive power back absorption or voltage build-up failure caused by frequency and voltage asynchrony.

[0083] Furthermore, the compensation coefficient Calibration is typically performed based on the generator's excitation characteristic curve and the equivalent excitation inductance of the main transformer to ensure that the compensation is linearly related to the speed deviation and does not introduce additional control overshoot. Response time index This is based on the dynamic response requirements for distributed power generation connected to the grid in the IEEE 1547-2018 standard, and combined with the actual operating conditions of hydropower plants (such as the rate of change of rotational speed). ) to optimize the design.

[0084] The continuous control method for generator-driven main transformer zero-start voltage boost in this embodiment of the invention can effectively eliminate electromagnetic shock and inrush current caused by step voltage boost, thereby improving equipment safety; it achieves smooth voltage rise through closed-loop PID control and feedforward compensation, significantly enhancing control stability; at the same time, it simplifies the operation process and improves the efficiency and reliability of black start and testing.

[0085] S5 automatically matches the boost rate according to the preset black start or maintenance test mode. and compensation coefficient It enables one-click trigger control under different working conditions.

[0086] Specifically, the boost rate is automatically matched according to the preset black start or maintenance test mode. and compensation coefficient This is a key step in realizing the generator-driven main transformer zero-start voltage boost control strategy. This step, by pre-setting control parameters for different operating conditions and combining them with the real-time system status, enables one-button trigger control, thereby improving the system's response flexibility and control accuracy.

[0087] In this embodiment of the invention, this step relies on the parameter configuration module and operating condition identification logic in the excitation control system. In black-start mode, after the system identifies the grid undervoltage state, it automatically loads a low initial voltage setpoint and matches an appropriate boost rate based on the main transformer capacity and system frequency characteristics. (Scope) In maintenance and testing mode, the system automatically adjusts the voltage boost rate and compensation coefficient according to the test type (such as phase verification or insulation testing). To adapt to different testing needs. Compensation coefficient The calculation formula used in the speed-voltage feedforward compensation module is as follows: ,in This refers to the real-time speed of the generator unit. Rated speed, This is the compensation amount for the excitation current. This compensation mechanism can effectively offset the voltage deviation caused by speed fluctuations, ensuring the stability of the voltage boosting process.

[0088] Furthermore, the boost rate The settings must meet the system frequency response requirements, and typically should not exceed [a certain value]. To avoid voltage overshoot and oscillation. Compensation coefficient The value of needs to be calibrated based on the characteristics of the excitation system and the equivalent parameters of the main transformer to ensure that the compensation response time is less than 1000 rpm. This enhances the dynamic adjustment capability.

[0089] This step is widely used in scenarios such as black start in hydropower plants, insulation testing after main transformer maintenance, and phase sequence verification. With a single click, the system can automatically load the control parameters for the corresponding mode, eliminating the need for manual intervention and significantly improving operational efficiency and safety.

[0090] The technical effect of this step is that it enables precise control under different operating conditions through automatic parameter matching, ensuring the continuity and stability of the pressurization process, reducing the risk of equipment impact and protection malfunction, and improving the system's adaptability and automation level, providing hydropower plants with an efficient and safe zero-start pressurization solution.

[0091] The continuous control method for generator-driven main transformer zero-start voltage boosting in this embodiment of the invention automatically matches the voltage boosting rate according to a preset black start or maintenance test mode. and compensation coefficient This further enables adaptive optimization of control parameters under different operating conditions, improves the accuracy and adaptability of system response, and thus enhances the safety and testing efficiency of equipment under complex operating conditions.

[0092] Example 2 This invention also provides a continuous control device for generator-driven main transformer zero-start voltage boost, such as... Figure 3 As shown, the device 10 includes: The initial voltage establishment module 100 is used to automatically trigger the soft start excitation program after the generator outlet circuit breaker is closed, so as to smoothly raise the generator terminal voltage from 0 to the low initial set value. The excitation current linear adjustment module 200 is used to linearly increase the excitation current according to a preset voltage rise rate after the initial voltage is established, so that the terminal voltage can be continuously increased to the rated voltage. The voltage deviation dynamic compensation module 300 is used to compare the terminal voltage with the target voltage in real time, dynamically adjust the excitation current output, and suppress overshoot and oscillation. The speed and frequency synchronization correction module 400 is used to automatically correct the excitation current output curve based on the real-time speed of the unit and the system frequency, so as to ensure voltage-frequency synchronization.

[0093] Example 3 To implement the methods of the above embodiments, the present invention also provides a computer device, which includes a memory and a processor; wherein the processor runs a program corresponding to the executable program code by reading executable program code stored in the memory, so as to implement the various steps of the methods described above.

[0094] Example 4 To implement the above embodiments, this application also proposes a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the method described in the foregoing embodiments.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A continuous control method for generator-driven main transformer zero-start voltage boost, characterized in that, Includes the following steps: S1, after the generator outlet circuit breaker is closed, the soft start excitation program is automatically triggered to smoothly raise the generator terminal voltage from 0 to the low initial set value. S2, after the initial voltage is established, the excitation current is increased linearly according to the preset voltage increase rate, so that the terminal voltage is continuously increased to the rated voltage; S3 compares the terminal voltage with the target voltage in real time and dynamically adjusts the excitation current output to suppress overshoot and oscillation; S4 automatically corrects the excitation current output curve based on the unit's real-time speed and system frequency to ensure voltage-frequency synchronization.

2. The method according to claim 1, characterized in that, After the generator output circuit breaker is closed, the soft start excitation program is automatically triggered to smoothly raise the generator terminal voltage from 0 to a low initial set value. This also includes: S11 uses a ramp function generator to control the excitation current and establishes the initial voltage with a constant slope; S12 limits the low initial setting value to 10% of the rated voltage to avoid inrush current caused by core saturation.

3. The method according to claim 1, characterized in that, The method of linearly increasing the excitation current at a preset voltage increase rate to continuously raise the terminal voltage to the rated voltage also includes: S21, preset boost rate for This ensures the continuity of voltage changes; S22, automatically adjusts the voltage boost rate according to the main transformer capacity. The range of values ​​is To meet the needs of different working conditions.

4. The method according to claim 1, characterized in that, The real-time comparison of the terminal voltage and the target voltage, and the dynamic adjustment of the excitation current output to suppress overshoot and oscillation, also includes: S31 adjusts the excitation current in real time through a closed-loop PID controller. Make the terminal voltage With target voltage The deviation is less than 0.5%; S32, Target Voltage It is generated by a linear function, and its expression is: in, For boost rate, For time, This is the initial setting value.

5. The method according to claim 1, characterized in that, The method of automatically correcting the excitation current output curve based on the real-time speed of the unit and the system frequency to ensure voltage-frequency synchronization also includes: S41, uses a speed-voltage feedforward compensator to calculate the compensation amount. The formula for calculating the compensation amount is: in, For compensation coefficient, Rated speed; S42, the response time of the feedforward compensator is less than... This offsets the impact of speed fluctuations on voltage-frequency synchronization.

6. The method according to claim 1, characterized in that, Also includes: S5 automatically matches the boost rate according to the preset black start or maintenance test mode. and compensation coefficient It enables one-click trigger control under different working conditions.

7. A continuous control device for generator-driven zero-start voltage boosting of main transformer, characterized in that, include: The initial voltage establishment module is used to automatically trigger the soft start excitation program after the generator outlet circuit breaker is closed, so as to smoothly raise the generator terminal voltage from 0 to the low initial set value. The excitation current linear adjustment module is used to linearly increase the excitation current according to a preset voltage rise rate after the initial voltage is established, so that the terminal voltage can be continuously increased to the rated voltage. The voltage deviation dynamic compensation module is used to compare the terminal voltage with the target voltage in real time, dynamically adjust the excitation current output, and suppress overshoot and oscillation. The speed and frequency synchronization correction module is used to automatically correct the excitation current output curve based on the real-time speed of the unit and the system frequency, so as to ensure voltage-frequency synchronization.

8. A computer device, characterized in that, Including processor and memory; The processor reads executable program code stored in the memory to run a program corresponding to the executable program code, so as to implement a continuous control method for generator-driven main transformer zero-start voltage boost as described in any one of claims 1-6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements a continuous control method for generator-driven main transformer zero-start voltage boost as described in any one of claims 1-6.

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