Transformer output voltage compensation device and method based on transformer load current

Abstract

The invention discloses a transformer output voltage compensation device and method based on transformer load current, and the device is characterized in that a current converter CT1 is connected to a load loop of a to-be-compensated transformer TR, and the output end of the current converter CT1 is connected to the primary side of a compensation isolation transformer GB1; the first end of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output end of the device, the first end of the secondary side of the compensation isolation transformer GB1 is connected to the first end of the variable resistor R1, and the second end of the secondary side of the compensation isolation transformer GB1 is connected to the first end of the variable inductor L1. The second end of the variable inductor L1 is connected to the second end of the variable resistor R1; the primary side of the isolation transformer GB2 is connected in parallel to the two ends of a transformer load R in the load loop of the transformer TR to be compensated, the first end of the secondary side of the isolation transformer GB2 is connected to the second end of the secondary side of the compensation isolation transformer GB1, and the second end of the secondary side of the isolation transformer GB2 serves as the second compensation voltage output end of the device.

Description

Technical Field

[0001] This invention relates to the field of power supply auxiliary equipment technology, and more specifically, to a transformer output voltage compensation device and method based on transformer load current. Background Technology

[0002] In power systems, transformers are the core equipment for power transmission, and the stability of their output voltage directly affects the quality of power supply. When the load current changes, the output voltage will drop significantly due to the resistance of the transformer windings and the leakage inductance. Especially under the condition of frequent start-stop of high-power industrial loads, the voltage fluctuation can reach 10%-15% of the rated value, which seriously affects the normal operation of sensitive equipment.

[0003] Traditional voltage compensation methods are mainly divided into two categories: one is on-load tap changer technology based on mechanical tap changers, which adjusts the output voltage by changing the position of the transformer tap changer, but suffers from slow adjustment speed (response time > 5s) and severe contact wear; the other uses static reactive power compensation devices or static synchronous compensators to offset voltage drop by injecting reactive current, but this type of solution can only compensate for reactive components and cannot solve the problem of resistive voltage drop, and the control system is complex and costly. In addition, existing electronic compensation devices mostly use fully controlled power devices (such as IGBTs) to build inverter circuits, which can achieve fast adjustment, but suffer from defects such as large switching losses and strong electromagnetic interference, resulting in low long-term reliability.

[0004] Therefore, a transformer output voltage compensation device based on transformer load current is needed. Summary of the Invention

[0005] This invention proposes a transformer output voltage compensation device and method based on transformer load current to solve the problem of how to compensate the output voltage of a transformer.

[0006] To address the aforementioned problems, according to one aspect of the present invention, a transformer output voltage compensation device based on transformer load current is provided. The device includes: a current converter CT1, a compensation isolation transformer GB1, a variable resistor R1, a variable inductor L1, and an isolation transformer GB2. The current converter CT1 is connected to the load circuit of the transformer TR to be compensated. The output terminal of the current converter CT1 is connected to the primary side of the compensation isolation transformer GB1. The first terminal of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output terminal of the device. The first terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable resistor R1. The second terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable inductor L1. The second terminal of the variable inductor L1 is connected to the second terminal of the variable resistor R1. The primary side of the isolation transformer GB2 is connected in parallel to both ends of the transformer load R in the load circuit of the transformer TR to be compensated. The first terminal of the secondary side of the isolation transformer GB2 is connected to the second terminal of the secondary side of the compensation isolation transformer GB1. The second terminal of the secondary side of the isolation transformer GB2 serves as the second compensation voltage output terminal of the device.

[0007] The current converter CT1 is used to acquire the current signal in the load circuit, convert the current signal into a first voltage signal, and connect the first voltage signal to the primary side of the compensation isolation transformer GB1.

[0008] The compensation isolation transformer GB1 is used to amplify the first voltage signal to obtain the second voltage signal;

[0009] The variable resistor R1 and variable inductor L1 are used to simulate the load on the output side of the compensation isolation transformer GB1. By adjusting the parameters of the variable resistor R1 and variable inductor L1, the control of the second voltage signal can be achieved.

[0010] The isolation transformer GB2 is used to transform the voltage on both sides of the load and to compensate for the voltage loss caused by the voltage drop of the isolation transformer GB2 based on the second voltage signal, thereby compensating for the voltage of the circuit between the isolation transformer GB1 and the isolation transformer GB2.

[0011] Preferably, the resistance value of the variable resistor R1 is determined using the following method:

[0012]

[0013] Where R1 is the resistance of the variable resistor R1; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; and n1 is the turns ratio of the compensation isolation transformer GB1.

[0014] Preferably, the inductance value of the variable inductor L1 is determined using the following method:

[0015]

[0016] Where L1 is the inductance value of the variable inductor L1; Z is the impedance of the transformer TR to be compensated; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; n1 is the turns ratio of the compensation isolation transformer GB1; and ω is the angular frequency.

[0017] Preferably, both the compensation isolation transformer GB1 and the isolation transformer GB2 are transformers with a square-shaped iron core, made of 30Q110 material, and a magnetic flux density of 0.7T to 1.1T.

[0018] Preferably, the current converter CT1 adopts a Rogowski coil structure, with the coil wound on an amorphous alloy toroidal core.

[0019] Preferably, the variable inductor L1 adopts an adjustable iron powder core structure, including three sets of winding coils arranged coaxially, with an epoxy resin insulation layer between each winding.

[0020] Preferably, an electromagnetic shielding layer is provided between the compensation isolation transformer GB1 and the isolation transformer GB2. The electromagnetic shielding layer is made of 0.5mm thick permalloy plate and the edges are sealed with conductive rubber.

[0021] Preferably, the device further includes an overvoltage protection unit connected between the first compensation voltage output terminal and the second compensation voltage output terminal, the overvoltage protection unit comprising a varistor and a bidirectional transient suppression diode connected in parallel.

[0022] According to another aspect of the present invention, a transformer output voltage compensation method based on the transformer output voltage compensation device based on transformer load current as described above is provided, the method comprising:

[0023] The current signal in the load circuit is acquired by the current converter CT1, and the current signal is converted into a first voltage signal, which is then connected to the primary side of the compensation isolation transformer GB1.

[0024] The first voltage signal is amplified using the compensation isolation transformer GB1 to obtain the second voltage signal;

[0025] By using variable resistor R1 and variable inductor L1, the load on the output side of the compensation isolation transformer GB1 is simulated. By slightly adjusting the parameters of variable resistor R1 and variable inductor L1, the control of the second voltage signal is achieved.

[0026] The output load of the compensation isolation transformer GB1 is simulated by using a variable resistor R1 and a variable inductor L1. By adjusting the parameters of the variable resistor R1 and the variable inductor L1, the control of the second voltage signal is achieved.

[0027] The voltage on both sides of the load is transformed by the isolation transformer GB2, and the voltage loss caused by the voltage drop of the isolation transformer GB2 is compensated based on the second voltage signal, thereby realizing the compensation of the circuit voltage of the isolation transformer GB1 and the isolation transformer GB2.

[0028] This invention provides a transformer output voltage compensation device and method based on transformer load current, comprising: a current converter CT1, a compensation isolation transformer GB1, a variable resistor R1, a variable inductor L1, and an isolation transformer GB2; wherein, the current converter CT1 is connected to the load circuit of the transformer TR to be compensated, the output terminal of the current converter CT1 is connected to the primary side of the compensation isolation transformer GB1, the first terminal of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output terminal of the device, the first terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable resistor R1, the second terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable inductor L1, and the second terminal of the variable inductor L1 is connected to the second terminal of the variable resistor R1; the primary side of the isolation transformer GB2 is connected in parallel to the two ends of the transformer load R in the load circuit of the transformer TR to be compensated, and the first terminal of the secondary side of the isolation transformer GB2 is connected to... The second terminal of the secondary side of the compensation isolation transformer GB1 and the second terminal of the secondary side of the isolation transformer GB2 serve as the second compensation voltage output terminal of the device. The current converter CT1 is used to collect the current signal in the load circuit, convert the current signal into a first voltage signal, and connect the first voltage signal to the primary side of the compensation isolation transformer GB1. The compensation isolation transformer GB1 is used to amplify the first voltage signal to obtain a second voltage signal. The variable resistor R1 and the variable inductor L1 are used to simulate the load on the output side of the compensation isolation transformer GB1. By adjusting the parameters of the variable resistor R1 and the variable inductor L1, the second voltage signal can be controlled. The isolation transformer GB2 is used to transform the voltage on both sides of the load and compensate for the voltage loss caused by the voltage drop of the isolation transformer GB2 based on the second voltage signal, thereby compensating for the voltage of the circuits of the compensation isolation transformers GB1 and GB2. This invention uses a current converter CT1 to monitor the load current of the transformer TR to be compensated in real time, and immediately performs voltage compensation through a compensation isolation transformer GB1, a variable inductor L1, and a variable resistor R1. This effectively shortens the response time and significantly improves the timeliness and accuracy of voltage compensation compared to traditional mechanical voltage regulators. It ensures that the output voltage fluctuation range is greatly reduced when the load current changes rapidly, thus guaranteeing the normal operation of sensitive equipment. At the same time, it can compensate for the resistance voltage drop and reactance voltage drop caused by the transformer winding resistance and leakage inductance, achieving a more comprehensive voltage compensation effect and improving power supply quality. By using a transformer and adjustable components to achieve voltage compensation, it can avoid the switching losses and electromagnetic interference caused by high-frequency switching operations, thus improving the long-term reliability and stability of the device. Attached Figure Description

[0029] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0030] Figure 1 This is a circuit diagram of a transformer output voltage compensation device based on transformer load current according to an embodiment of the present invention;

[0031] Figure 2 This is a flowchart of a transformer output voltage compensation method according to an embodiment of the present invention. Detailed Implementation

[0032] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0033] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0034] Figure 1 This is a circuit diagram of a transformer output voltage compensation device based on transformer load current according to an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention provides a transformer output voltage compensation device, including: a current converter CT1, a compensation isolation transformer GB1, a variable resistor R1, a variable inductor L1, and an isolation transformer GB2. a and n are the output terminals of the secondary side of the transformer TR to be compensated, a' and n' are the output terminals of the load circuit, a11 and n11 are the output terminals of the current converter CT1, a22 and n22 are the output terminals of the compensation isolation transformer GB1, and a33 and n33 are the output terminals of the isolation transformer GB2.

[0035] The current converter CT1 is connected to the load circuit of the transformer TR to be compensated. The output terminal of the current converter CT1 is connected to the primary side of the compensation isolation transformer GB1. The first terminal of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output terminal of the device. The first terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable resistor R1. The second terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable inductor L1. The second terminal of the variable inductor L1 is connected to the second terminal of the variable resistor R1. The primary side of the isolation transformer GB2 is connected in parallel to the two ends of the transformer load R in the load circuit of the transformer TR to be compensated. The first terminal of the secondary side of the isolation transformer GB2 is connected to the second terminal of the secondary side of the compensation isolation transformer GB1. The second terminal of the secondary side of the isolation transformer GB2 serves as the second compensation voltage output terminal of the device.

[0036] The current converter CT1 is used to acquire the current signal in the load circuit, convert the current signal into a first voltage signal, and connect the first voltage signal to the primary side of the compensation isolation transformer GB1.

[0037] The compensation isolation transformer GB1 is used to amplify the first voltage signal to obtain the second voltage signal.

[0038] The variable resistor R1 and variable inductor L1 are used to simulate the load on the output side of the compensation isolation transformer GB1. By adjusting the parameters of the variable resistor R1 and variable inductor L1, the control of the second voltage signal is realized.

[0039] The isolation transformer GB2 is used to transform the voltage on both sides of the load and to compensate for the voltage loss caused by the voltage drop of the isolation transformer GB2 based on the second voltage signal, thereby compensating for the voltage of the circuit between the isolation transformer GB1 and the isolation transformer GB2.

[0040] Preferably, the resistance value of the variable resistor R1 is determined using the following method:

[0041]

[0042] Where R1 is the resistance of the variable resistor R1; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; and n1 is the turns ratio of the compensation isolation transformer GB1.

[0043] Preferably, the inductance value of the variable inductor L1 is determined using the following method:

[0044]

[0045] Where L1 is the inductance value of the variable inductor L1; Z is the impedance of the transformer TR to be compensated; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; n1 is the turns ratio of the compensation isolation transformer GB1; and ω is the angular frequency.

[0046] Preferably, both the compensation isolation transformer GB1 and the isolation transformer GB2 are transformers with a square-shaped iron core, made of 30Q110 material, and a magnetic flux density of 0.7T to 1.1T.

[0047] Preferably, the current converter CT1 adopts a Rogowski coil structure, with the coil wound on an amorphous alloy toroidal core.

[0048] Preferably, the variable inductor L1 adopts an adjustable iron powder core structure, including three sets of winding coils arranged coaxially, with an epoxy resin insulation layer between each winding.

[0049] Preferably, an electromagnetic shielding layer is provided between the compensation isolation transformer GB1 and the isolation transformer GB2. The electromagnetic shielding layer is made of 0.5mm thick permalloy plate and the edges are sealed with conductive rubber.

[0050] Preferably, the device further includes an overvoltage protection unit connected between the first compensation voltage output terminal and the second compensation voltage output terminal, the overvoltage protection unit comprising a varistor and a bidirectional transient suppression diode connected in parallel.

[0051] The transformer output voltage compensation device based on transformer load current provided in this invention has the following advantages:

[0052] 1. Improved voltage compensation accuracy and response speed: This invention monitors the load current of the transformer TR to be compensated in real time through the current converter CT1, and immediately performs voltage compensation through the compensation isolation transformer GB1, variable inductor L1, and variable resistor R1, effectively shortening the response time. Compared with traditional mechanical voltage regulators (response time > 5s), it significantly improves the timeliness and accuracy of voltage compensation, ensuring that the output voltage fluctuation range is greatly reduced when the load current changes rapidly, thus guaranteeing the normal operation of sensitive equipment.

[0053] 2. Comprehensive compensation for resistance and reactance voltage drop: Unlike traditional static reactive power compensation devices that can only compensate for reactance components, this invention, through the synergistic effect of the compensation isolation transformer GB1 and the variable inductor L1 and variable resistor R1, can simultaneously compensate for the resistance voltage drop and reactance voltage drop caused by the transformer winding resistance and leakage inductance, achieving a more comprehensive voltage compensation effect and improving power supply quality.

[0054] 3. Reduces switching losses and electromagnetic interference: Compared with electronic compensation devices that use fully controlled power devices (such as IGBTs) to build inverter circuits, this invention achieves voltage compensation through transformers and adjustable components, avoiding switching losses and electromagnetic interference caused by high-frequency switching operations, and improving the long-term operational reliability and stability of the device.

[0055] 4. The design principle is reliable, the structure is simple, and it has a very wide range of application prospects.

[0056] Specifically, such as Figure 1 As shown, the transformer output voltage compensation device provided in this embodiment of the invention includes a current converter CT1, a compensation isolation transformer GB1, a variable resistor R1, a variable inductor L1, and an isolation transformer GB2; the current converter CT1 is connected to the load circuit of the transformer TR to be compensated, and the output terminal of the current converter CT1 ( Figure 1 a11 and n11 are connected to the primary side of the compensation isolation transformer GB1, and the first terminal of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output terminal of the device. Figure 1 (n22 in the text), the first terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable resistor R1, and the second terminal of the secondary side of the compensation isolation transformer GB1 ( Figure 1 (a22) is connected to the first terminal of the variable inductor L1, and the second terminal of the variable inductor L1 is connected to the second terminal of the variable resistor R1; the primary side of the isolation transformer GB2 is connected in parallel to the two ends of the transformer load R in the load circuit of the transformer TR to be compensated, and the first terminal of the secondary side of the isolation transformer GB2 ( Figure 1 n33) is connected to the second terminal of the secondary side of the compensation isolation transformer GB1, and the second terminal of the secondary side of the isolation transformer GB2 ( Figure 1 a33) is used as the second compensation voltage output terminal of the device.

[0057] Unlike traditional static reactive power compensation devices that can only compensate for reactance components, this invention, through the synergistic effect of the compensation isolation transformer GB1 and the variable inductor L1 and variable resistor R1, can simultaneously compensate for the resistance voltage drop and reactance voltage drop caused by the transformer winding resistance and leakage inductance, achieving a more comprehensive voltage compensation effect and improving power supply quality.

[0058] Specifically, the formula for calculating the resistance value of the variable resistor R1 is as follows:

[0059]

[0060] Where R2 is the DC resistance at the input terminal of the transformer TR to be compensated, in ohms; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance at the output terminal of the transformer TR to be compensated, in ohms; and n1 is the turns ratio of the compensation isolation transformer GB1.

[0061] Furthermore, the formula for calculating the inductance value of the variable inductor L1 is as follows:

[0062]

[0063] Where Z is the impedance of the transformer TR to be compensated, in ohms; ω is the angular frequency, in radians per second.

[0064] In a practical power system application scenario, taking a distribution transformer operating in an industrial park as an example, this paper details the specific implementation process of the calculation formulas for variable resistor R1 and variable inductor L1. This distribution transformer has a primary rated voltage of 10kV and a secondary rated voltage of 0.4kV, primarily supplying power to numerous industrial enterprises within the park. Due to the complex operation of industrial equipment and frequent fluctuations in load current within the park, the stability of the transformer's output voltage poses a significant challenge.

[0065] First, the parameters of the distribution transformer (the transformer to be compensated, TR) are clarified: By reviewing the factory test report and actual on-site measurements, its short-circuit impedance voltage is 6.2%, primary rated current is 45A, secondary rated current is 1125A, high-voltage side DC resistance (DC resistance R2 at the input terminal of the transformer to be compensated, TR) is 0.78Ω, and low-voltage side DC resistance (DC resistance R3 at the output terminal of the transformer to be compensated, TR) is 0.00085Ω. Based on the short-circuit impedance voltage and rated current, the impedance Z of the transformer to be compensated, TR, is calculated to be 0.022Ω. The angular frequency ω during operation, under a 50Hz AC power frequency, is ω=2πf=2×3.14×50=3=314 radians per second. The turns ratio n1 of the compensation isolation transformer GB1, after circuit simulation and actual debugging optimization using ATP (Alternative Transients Program), is selected as 1:12. The turns ratio n of the transformer to be compensated, TR, is 10kV:0.4kV, or 25.

[0066] Based on the formula for calculating the resistance of variable resistor R1 Substituting the above parameters, the resistance value of the variable resistor R1 should be adjusted to approximately 0.000175 ohms.

[0067] To calculate the inductance value of the variable inductor L1, substitute the above parameters into the formula. The calculated inductance value of the variable inductor L1 is approximately 5.81 microhenries. In industrial production and other scenarios, stable voltage is crucial for the normal operation of equipment. The above calculation formula ensures that the compensation device can quickly respond to changes in load current. Taking an industrial park as an example, when a large number of industrial devices frequently start or stop, causing drastic fluctuations in load current, the adjusted R1 and L1, calculated according to the formula, can rapidly change the magnitude and characteristics of the compensation voltage. Compared to traditional compensation methods, this calculation-based compensation method effectively reduces the impact of voltage fluctuations on sensitive equipment, lowers the probability of equipment failure due to voltage issues, extends equipment lifespan, and improves production efficiency and product quality.

[0068] In this invention, the calculation formulas for the variable resistor R1 and the variable inductor L1 are based on detailed parameters of the transformer, including input and output DC resistance, turns ratio, impedance, and angular frequency. These parameters comprehensively reflect the electrical characteristics of the transformer. By accurately substituting these parameters into the calculations, the resistance value of R1 and the inductance value of L1 can be precisely adjusted.

[0069] Variable resistor R1 and variable inductor L1 are used to simulate the load on the output side of the compensation isolation transformer GB1. Adjusting the parameters of variable resistor R1 and variable inductor L1 controls the second voltage signal. In actual operation, when changes in the transformer load current cause output voltage fluctuations, the circuit consisting of R1 and L1 works in conjunction with the compensation isolation transformer GB1 to accurately compensate for voltage drops. Both resistive voltage drops and reactance voltage drops are effectively compensated, keeping the output voltage within a minimal range of the theoretical value, ensuring the stability of the supply voltage and meeting the power requirements of equipment with high voltage accuracy requirements.

[0070] Because the calculation formula considers various transformer parameters, this compensation device can adapt to transformers of different specifications and operating conditions. Regardless of the transformer's voltage level, capacity, or winding structure, as long as accurate parameters are obtained and substituted into the formula, appropriate R1 and L1 values ​​can be determined. This means that the same compensation device can be applied in various power system environments, reducing the cost and time of designing compensation equipment specifically for different transformers, improving the equipment's versatility and interchangeability, and facilitating power system maintenance and upgrades. From the perspective of the power system as a whole, accurate voltage compensation helps reduce line losses. Stable voltage reduces unreasonable reactive power flow and improves the power factor. When the compensation device accurately compensates for the voltage through calculation, the current in the transformer and transmission lines becomes more stable, avoiding excessive or insufficient current caused by voltage fluctuations, reducing line heating losses, improving the operating efficiency and economy of the power system, and also alleviating the burden on the grid, thus enhancing the stability and reliability of the entire power system.

[0071] Both the compensation isolation transformer GB1 and the isolation transformer GB2 are U-shaped cores, made of 30Q110 steel, and have a magnetic flux density of 0.7T to 1.1T. The use of U-shaped cores and 30Q110 steel in these transformers effectively improves their electromagnetic conversion efficiency. The 30Q110 steel has low hysteresis and eddy current losses, reducing energy loss in the magnetic circuit during operation and allowing for more efficient conversion and transmission of electrical energy. The U-shaped core structure optimizes the magnetic circuit distribution, making magnetic lines of force more concentrated and uniform, enhancing the transformer's coupling effect, and thus improving the stability and accuracy of voltage conversion. Within the 0.7T to 1.1T magnetic flux density range, this material and core structure work well together, ensuring stable operation of the transformer under different load conditions, guaranteeing the stability of the compensation device's output voltage, reducing voltage fluctuations, and providing a more stable power supply for subsequent electrical equipment.

[0072] Furthermore, an electromagnetic shielding layer is installed between the compensation isolation transformer GB1 and the isolation transformer GB2. This shielding layer is composed of a 0.5mm thick permalloy plate, with conductive rubber sealing at the edges. In a power system, transformers generate electromagnetic interference during operation, affecting the normal operation of surrounding equipment. The electromagnetic shielding layer, composed of a 0.5mm thick permalloy plate, between the compensation isolation transformer GB1 and the isolation transformer GB2 effectively blocks and absorbs electromagnetic radiation between the transformers. Permalloy has high magnetic permeability and strong shielding ability against magnetic fields, significantly reducing electromagnetic coupling interference between the two transformers. The conductive rubber seal at the edges ensures the integrity of the shielding layer, prevents electromagnetic leakage, and further enhances the shielding effect. This not only reduces interference to other electronic components inside the compensation device, improving the device's own reliability and stability, but also avoids electromagnetic interference to surrounding power and electronic equipment, ensuring the electromagnetic compatibility of the entire power system and guaranteeing the normal operation of other equipment.

[0073] Furthermore, the CT1 current converter employs a Rogowski coil structure, with the coil wound around an amorphous alloy toroidal core. This Rogowski coil structure enables high-precision current measurement. The Rogowski coil is an air-core coil, free from magnetic saturation issues, and offers a wide measurement range. The amorphous alloy toroidal core possesses high permeability, low coercivity, and low loss characteristics, effectively focusing and guiding the magnetic field, enhancing the coil's ability to induce a magnetic field in response to current. When measuring transformer load circuit current, even with large current variations, from minute currents to large inrush currents, this type of current converter accurately converts the current signal into a voltage signal, ensuring accurate and reliable current data. This provides a precise basis for subsequent voltage compensation based on the current signal, ensuring that the compensation device can adjust the compensation voltage promptly and accurately according to actual current changes, thus improving the accuracy of voltage compensation.

[0074] Furthermore, the variable inductor L1 employs an adjustable iron powder core structure, comprising three coaxially arranged winding coils, with epoxy resin insulation layers between each winding. This adjustable iron powder core structure provides high flexibility in inductance value adjustment. By changing the position of the iron powder core within the windings, the inductance can be easily adjusted. In transformer output voltage compensation, the load characteristics and operating conditions are complex and constantly changing, making this flexible adjustment capability crucial. When changes in transformer load current cause output voltage fluctuations, the inductance value of the variable inductor L1 can be quickly adjusted based on real-time monitoring data. For example, when an increase in load current causes a voltage drop, the inductance value is increased to enhance the voltage compensation effect; when the load current decreases, the inductance value is decreased to avoid over-compensation, ensuring the output voltage remains stable within the specified range and effectively improving the accuracy of voltage compensation. The structure consisting of three coaxially arranged winding coils optimizes the magnetic field distribution of the inductor. The three windings work together to make the magnetic field more uniform and concentrated, reducing leakage flux and improving the inductor's operating efficiency. Meanwhile, the epoxy resin insulation layer between each winding not only effectively prevents short-circuit faults between windings but also enhances the electrical insulation performance of the inductor, ensuring stable operation under high voltage and strong electric field environments. In power systems, voltage and current fluctuations may generate instantaneous high-voltage pulses. The epoxy resin insulation layer can withstand these pulse impacts, ensuring the normal operation of the variable inductor L1, extending its service life, and thus improving the reliability of the entire transformer output voltage compensation device.

[0075] Furthermore, the device also includes an overvoltage protection unit connected between the first compensation voltage output terminal and the second compensation voltage output terminal. The overvoltage protection unit consists of a varistor and a bidirectional transient suppression diode connected in parallel.

[0076] For example, in the power supply system of an industrial park, a transformer output voltage compensation device like the one described above was installed. The park contains numerous large chemical production lines, which generate significant current surges during startup and shutdown, leading to substantial fluctuations in the transformer output voltage and posing an overvoltage risk.

[0077] After the compensation device was put into use, when a large chemical pump started, the instantaneous increase in motor starting current caused a sudden rise in the transformer output voltage. At this moment, the overvoltage protection unit connected between the first and second compensation voltage output terminals reacted quickly. Upon sensing the voltage increase, the varistor's resistance rapidly decreased, initiating conduction and current shunting, dissipating some of the overvoltage energy. Simultaneously, the bidirectional transient voltage suppressor diode also activated, utilizing its rapid response to clamp the remaining overvoltage, stabilizing the output voltage within a safe range. Through the overvoltage protection unit, the output voltage, which might have exceeded the normal range, was limited to within the permissible fluctuation range, protecting other voltage-sensitive chemical production equipment in the industrial park from damage by excessive voltage and ensuring the continuity and stability of the chemical production process.

[0078] like Figure 2 As shown, the transformer output voltage compensation method provided by the embodiments of the present invention, based on the transformer output voltage compensation device based on the transformer load current as described above, includes:

[0079] Step 201: Use current converter CT1 to collect the current signal in the load circuit, convert the current signal into a first voltage signal, and connect the first voltage signal to the primary side of compensation isolation transformer GB1;

[0080] Step 202: Amplify the first voltage signal using the compensation isolation transformer GB1 to obtain the second voltage signal;

[0081] Step 203: Use variable resistor R1 and variable inductor L1 to simulate the load on the output side of the compensation isolation transformer GB1. By adjusting the parameters of variable resistor R1 and variable inductor L1, control of the second voltage signal is achieved.

[0082] Step 204: Use isolation transformer GB2 to transform the voltage on both sides of the load, and compensate for the voltage loss caused by the voltage drop of isolation transformer GB2 based on the second voltage signal, thereby realizing the compensation of the circuit voltage of isolation transformer GB1 and isolation transformer GB2.

[0083] The working principle of the voltage compensation device in this invention is as follows: A current converter CT1 is connected to the load circuit of the transformer TR to be compensated. It employs a Rogowski coil structure wound on an amorphous alloy toroidal core, enabling high-precision and rapid acquisition of the current signal in the load circuit and conversion into a voltage signal. The voltage signal output from the current converter CT1 is connected to the primary side of the compensation isolation transformer GB1. GB1 has a turns ratio of 1:n (n>1), amplifying the input voltage. The voltage output from its secondary side is used to compensate for the voltage drop caused by the transformer winding resistance and leakage inductance. Furthermore, through cooperation with a circuit composed of a variable resistor R1 and a variable inductor L1, it achieves fine adjustment of the compensation voltage. The resistance and inductance values ​​of the variable resistor R1 and the variable inductor L1 are precisely calculated and determined based on the transformer parameters (such as input DC resistance, output DC resistance, turns ratio, impedance, etc.). When the load current changes, the magnitude and characteristics of the compensation voltage can be flexibly changed by adjusting the values ​​of R1 and L1 to adapt to different load conditions. The primary side of isolation transformer GB2 is connected in parallel across the load R of the transformer to be compensated TR, transforming the voltage across the load. Due to the voltage drop across the transformer, the actual output voltage on the load side is lower than the theoretical value, and the output voltage of isolation transformer GB2 will also decrease accordingly. At this time, the output circuit of compensation isolation transformer GB1 is connected in series with the output circuit of isolation transformer GB2. The voltage output of GB1 is used to compensate for the voltage loss of GB2 output voltage due to the voltage drop. By short-circuiting the output sides of compensation isolation transformer GB1 and isolation transformer GB2, a specific potential is raised, thus compensating for the voltage of the compensation isolation transformer GB1-GB2 circuit, making the final compensated output voltage closer to the theoretical value.

[0084] The present invention has been described with reference to a few embodiments. However, it will be apparent to those skilled in the art that other embodiments besides those disclosed above fall equivalently within the scope of the present invention.

[0085] Generally, all terms used in this invention are interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0086] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0087] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0088] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0089] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A transformer output voltage compensation device based on transformer load current, characterized in that, The device includes: a current converter CT1, a compensation isolation transformer GB1, a variable resistor R1, a variable inductor L1, and an isolation transformer GB2; wherein, the current converter CT1 is connected to the load circuit of the transformer TR to be compensated, the output terminal of the current converter CT1 is connected to the primary side of the compensation isolation transformer GB1, the first terminal of the secondary side of the compensation isolation transformer GB1 serves as the first compensation voltage output terminal of the device, the first terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable resistor R1, the second terminal of the secondary side of the compensation isolation transformer GB1 is connected to the first terminal of the variable inductor L1, and the second terminal of the variable inductor L1 is connected to the second terminal of the variable resistor R1; the primary side of the isolation transformer GB2 is connected in parallel to the two ends of the transformer load R in the load circuit of the transformer TR to be compensated, the first terminal of the secondary side of the isolation transformer GB2 is connected to the second terminal of the secondary side of the compensation isolation transformer GB1, and the second terminal of the secondary side of the isolation transformer GB2 serves as the second compensation voltage output terminal of the device; wherein, The current converter CT1 is used to acquire the current signal in the load circuit, convert the current signal into a first voltage signal, and connect the first voltage signal to the primary side of the compensation isolation transformer GB1. The compensation isolation transformer GB1 is used to amplify the first voltage signal to obtain the second voltage signal; The variable resistor R1 and variable inductor L1 are used to simulate the load on the output side of the compensation isolation transformer GB1. By adjusting the parameters of the variable resistor R1 and variable inductor L1, the control of the second voltage signal can be achieved. The isolation transformer GB2 is used to transform the voltage on both sides of the load and to compensate for the voltage loss caused by the voltage drop of the isolation transformer GB2 based on the second voltage signal, thereby compensating for the voltage of the circuit between the isolation transformer GB1 and the isolation transformer GB2.

2. The transformer output voltage compensation device according to claim 1, characterized in that, The resistance value of the variable resistor R1 is determined using the following methods: Where R1 is the resistance of the variable resistor R1; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; and n1 is the turns ratio of the compensation isolation transformer GB1.

3. The transformer output voltage compensation device according to claim 1, characterized in that, The inductance value of the variable inductor L1 is determined using the following methods: Where L1 is the inductance value of the variable inductor L1; Z is the impedance of the transformer TR to be compensated; R2 is the DC resistance of the input terminal of the transformer TR to be compensated; n is the turns ratio of the transformer TR to be compensated; R3 is the DC resistance of the output terminal of the transformer TR to be compensated; n1 is the turns ratio of the compensation isolation transformer GB1; and ω is the angular frequency.

4. The transformer output voltage compensation device according to claim 1, characterized in that, Both the compensation isolation transformer GB1 and the isolation transformer GB2 are transformers with a square-shaped iron core, made of 30Q110 material, and a magnetic flux density of 0.7T to 1.1T.

5. The transformer output voltage compensation device according to claim 1, characterized in that, The current converter CT1 adopts a Rogowski coil structure, with the coil wound on an amorphous alloy toroidal core.

6. The transformer output voltage compensation device according to claim 1, characterized in that, The variable inductor L1 adopts an adjustable iron powder core structure, including three sets of winding coils arranged coaxially, with an epoxy resin insulation layer between each winding.

7. The transformer output voltage compensation device according to claim 1, characterized in that, An electromagnetic shielding layer is provided between the compensation isolation transformer GB1 and the isolation transformer GB2. The electromagnetic shielding layer is made of 0.5mm thick permalloy plate and the edges are sealed with conductive rubber.

8. The transformer output voltage compensation device according to claim 1, characterized in that, The device further includes an overvoltage protection unit connected between the first compensation voltage output terminal and the second compensation voltage output terminal, the overvoltage protection unit comprising a varistor and a bidirectional transient suppression diode connected in parallel.

9. A transformer output voltage compensation method for a transformer output voltage compensation device based on transformer load current according to any one of claims 1-8, characterized in that, The method includes: The current signal in the load circuit is acquired by the current converter CT1, and the current signal is converted into a first voltage signal, which is then connected to the primary side of the compensation isolation transformer GB1. The first voltage signal is amplified using the compensation isolation transformer GB1 to obtain the second voltage signal; The output load of the compensation isolation transformer GB1 is simulated by using a variable resistor R1 and a variable inductor L1. By adjusting the parameters of the variable resistor R1 and the variable inductor L1, the control of the second voltage signal is achieved. The voltage on both sides of the load is transformed by the isolation transformer GB2, and the voltage loss caused by the voltage drop of the isolation transformer GB2 is compensated based on the second voltage signal, thereby realizing the compensation of the circuit voltage of the isolation transformer GB1 and the isolation transformer GB2.

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