Transformer secondary side multi-winding switching safety control method
By constructing a dual-closed-loop collaborative control architecture on the secondary side of the transformer, the problem of inaccurate voltage during multi-winding switching at the output end of the frequency converter was solved, achieving precise control and safe transition of the transformer output voltage, and improving the stability and safety of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WOLONG ELECTRIC GRP CO LTD
- Filing Date
- 2025-12-25
- Publication Date
- 2026-04-28
AI Technical Summary
When multiple windings of different voltage levels are connected to the secondary side of a transformer at the output end of a frequency converter, existing technologies make it difficult to accurately control the output voltage level of the transformer, resulting in inaccurate voltage drop compensation and potential safety hazards.
A dual-closed-loop collaborative control architecture based on direct feedback of secondary side voltage is constructed. Combining parameter preset and safety interlocking logic, the output voltage is monitored and adjusted in real time through frequency phase closed loop and voltage amplitude closed loop to ensure smooth transition and voltage stability during the switching process.
It enables precise voltage control during the switching process of multiple windings on the secondary side of the transformer, improves the safety and reliability of the system, reduces electrical shocks and equipment risks, and is suitable for complex industrial sites.
Smart Images
Figure CN121939862A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of power electronics and industrial control, specifically to a safety control method for switching multiple windings on the secondary side of a transformer. Background Technology
[0002] In modern industrial power supply systems, frequency converters are widely used due to their excellent speed regulation and energy-saving performance. In certain specific scenarios, such as shore power in large ports, mining machinery, and specific production lines, frequency converters are required to supply power to multiple devices or workstations with different voltage levels through a single transformer. This is usually achieved by configuring multiple windings on the secondary side of the transformer.
[0003] Currently, under the background of variable frequency drive output voltage control technology, the closed-loop control of the voltage amplitude and frequency output of the variable frequency power supply mainly relies on a voltage acquisition device. This voltage acquisition device is mostly installed on the output side of the variable frequency drive, that is, between the variable frequency drive and the transformer. When there are multiple windings with different voltage levels on the secondary side of the transformer connected to the output end of the variable frequency drive, this control method cannot accurately control the different voltage levels output by the secondary side of the transformer.
[0004] The reason is that the voltage drop occurs when the three-phase power output from the frequency converter passes through the transformer. The frequency converter usually increases the voltage to compensate for the voltage drop. However, when using different windings on the secondary side of the transformer, the voltage drop is different due to the different output voltage levels and output currents. Therefore, it is difficult to accurately compensate for the voltage drop by compensating the output voltage when switching windings. In view of the above technical problems, this invention proposes a solution. Summary of the Invention
[0005] This invention addresses the problem of inaccurate output voltage and potential safety hazards caused by inaccurate voltage drop compensation during multi-winding switching of transformer secondary sides in existing technologies. It proposes a safety control method for multi-winding switching of transformer secondary sides. This method is achieved by constructing a dual-closed-loop collaborative control architecture based on direct feedback of secondary side voltage, combined with parameter preset and safety interlocking logic, to realize a smooth transition during winding switching and precise stability of output voltage.
[0006] The objective of this invention can be achieved through the following technical solution: a safety control method for multi-winding switching on the secondary side of a transformer, comprising the following steps: Step 1: Preset the target voltage setpoint, the turns ratio parameters of the voltage transformer on the secondary side of the transformer for each winding, as well as the allowable voltage fluctuation safety threshold and current fluctuation safety threshold. Step 2: When a winding switching command is received from the outside or a switching requirement is generated by the internal logic of the system, the target winding number is identified, and the feedback channel switching and parameter transmission operations are executed synchronously. Step 3: Simultaneously run the frequency phase closed loop and the voltage amplitude closed loop; Step 4: During the switching process and steady-state operation, monitor the voltage and current feedback values on the target winding side in real time and compare them with the preset safety threshold; if the monitored value exceeds the safety range, the protection logic will be triggered immediately. Step 5: The protection logic includes the following steps in sequence: freezing the switching process, locking the current output, issuing an audible and visual alarm, or executing a safety shutdown procedure until the fault is cleared.
[0007] As a preferred embodiment of the present invention, it also includes a parameter preset module, a signal acquisition and switching module, a dual closed-loop collaborative control module, and a safety interlock and status monitoring module. The parameter preset module is used to obtain the preset winding-related parameters for each winding on the secondary side of the transformer; The signal acquisition and switching module is used to receive winding switching instructions, identify the target winding number, switch the feedback channel, and send winding-related parameters to the dual closed-loop collaborative control module. The dual-closed-loop collaborative control module is used to simultaneously operate the frequency phase closed loop and the voltage amplitude closed loop. The safety interlock and status monitoring module is used to monitor the voltage and current feedback values on the target winding side in real time, and to make threshold judgments. Based on the threshold judgment results, the protection logic is automatically triggered to perform troubleshooting operations.
[0008] In a preferred embodiment of the present invention, the winding-related parameters obtained by the parameter preset module include: target voltage setpoint, voltage transformer ratio parameters, and allowable voltage fluctuation safety threshold and current fluctuation safety threshold.
[0009] In a preferred embodiment of the present invention, the method for switching the feedback channel by the signal acquisition and switching module is as follows: Switch the voltage feedback signal acquisition channel from the voltage transformer on the current winding side to the voltage transformer on the target winding side; The winding-related parameters sent by the signal acquisition and switching module to the dual closed-loop collaborative control module are: the target voltage setpoint and turns ratio parameters of the corresponding target winding.
[0010] As a preferred embodiment of the present invention, the method for the dual-closed-loop cooperative control module to operate the frequency-phase closed loop is as follows: Given the required frequency and phase of the system, the voltage signal from the output side of the inverter is collected as feedback, and the frequency and phase of the modulation wave are adjusted by the first PID regulator to ensure the frequency stability of the output power supply. The method of the dual closed-loop collaborative control module to operate the voltage amplitude closed loop is as follows: the target winding voltage given by the signal acquisition and switching module is used as the reference, and the actual voltage signal of the target winding side acquired by the signal acquisition and switching module after switching is used as the feedback, and the voltage amplitude of the modulation wave is adjusted by the second PID regulator. The dual-closed-loop collaborative control module generates the final PWM modulation wave through the combined action of the outputs of the two closed loops, driving the inverter power unit output.
[0011] In a preferred embodiment of the present invention, the signal acquisition and switching module includes multiple analog input channels and a high-speed digital switch, which are respectively connected to the output of the voltage transformer on each winding side; when the signal acquisition and switching module receives a switching command, it selects the corresponding channel through the high-speed digital switch to perform software switching of the feedback signal.
[0012] In a preferred embodiment of the present invention, the switching strategy of the PID regulator of the voltage amplitude closed loop in the dual closed-loop collaborative control module is as follows: in the first control cycle after the switching is completed, the initial value of the integral term of the PID regulator is set to the output value of the previous winding in steady state, and the proportional coefficient is reduced to suppress the voltage surge that may occur at the moment of switching.
[0013] In a preferred embodiment of the present invention, the parameter preset module further presets the minimum stable operating time of each winding, and the safety interlock and status monitoring module starts timing after the switching is completed. Before the minimum stable operating time of the winding is reached, non-urgent external switching commands are blocked.
[0014] In a preferred embodiment of the present invention, an adaptive learning unit is also included: the unit records the steady-state compensation amount required by the second PID regulator to reach the target voltage setpoint after each switching; after multiple switching of the same winding, the preset target voltage setpoint or PID parameters of the corresponding winding are finely adjusted through algorithm learning to further eliminate system errors.
[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention directly extracts the feedback signal of the voltage closed loop from the target winding on the secondary side of the transformer, fundamentally solving the problem of inaccurate voltage drop compensation caused by different winding parameters, ensuring the accuracy of the output voltage of each winding, and meeting high-standard power requirements.
[0016] This invention also introduces an independent safety interlock and status monitoring module, and embeds strategies such as smooth initialization and minimum stabilization time protection into the control logic, which effectively suppresses electrical shocks during the switching process, prevents equipment risks caused by misoperation and frequent switching, and improves the overall safety and reliability of the system.
[0017] This invention also combines a parameter preset module with an adaptive learning unit, enabling the system to not only respond quickly to switching commands, but also to self-optimize using historical data, reducing manual debugging workload and making the control process more intelligent and precise, suitable for complex and ever-changing industrial environments. Attached Figure Description
[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.
[0019] Figure 1 This is a system block diagram of the present invention; Figure 2 This is a system flowchart of the present invention. Detailed Implementation
[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0021] Example 1: Please refer to Figure 1 - Figure 2 As shown, a safety control method for switching multiple windings on the secondary side of a transformer is applied to a power supply system including a frequency converter and a multi-winding transformer. The method is characterized by being executed collaboratively by a parameter preset module, a signal acquisition and switching module, a dual closed-loop collaborative control module, and a safety interlocking and status monitoring module integrated into the frequency converter control system. The method includes the following steps: Step 1: Parameter Preset and Initialization: Before the system is put into operation, the parameter preset module is used to preset the corresponding target voltage setpoint, the turns ratio parameter of the voltage transformer on the secondary side of the transformer, and the allowable voltage / current fluctuation safety threshold for each winding. Step 2: Switching signal identification and feedback channel switching: When a winding switching command is received from the outside or a switching requirement generated by the internal logic of the system, the signal acquisition and switching module identifies the target winding number and performs two operations simultaneously: (1) physically or logically switching the voltage feedback signal acquisition channel from the voltage transformer on the current winding side to the voltage transformer on the target winding side; (2) sending the target voltage setpoint and turns ratio parameters of the corresponding target winding in the parameter preset module to the dual closed-loop collaborative control module; Step 3: Dual-Loop Cooperative Control Execution: The dual-loop cooperative control module simultaneously runs the frequency phase closed loop and the voltage amplitude closed loop. Specifically: The frequency and phase closed loop is as follows: taking the required frequency and phase of the system as a given, the voltage signal on the output side of the inverter is collected as feedback, and the frequency and phase of the modulation wave are adjusted by the first PID regulator to ensure the frequency stability of the output power supply. The voltage amplitude closed loop is as follows: the target winding voltage given value obtained in step S2 is used as the reference, and the actual voltage signal of the target winding side collected after switching in step S2 is used as the feedback. The voltage amplitude of the modulation wave is adjusted by the second PID regulator. The outputs of the two closed loops work together to generate the final PWM modulation wave, which drives the inverter power unit output; Step 4: Safety Interlocking and Status Monitoring: During the switching process and steady-state operation, the safety interlocking and status monitoring module monitors the voltage and current feedback values on the target winding side in real time and compares them with the preset safety threshold. If the monitored value exceeds the safety range, the protection logic is immediately triggered. The protection logic includes: freezing the switching process, locking the current output, issuing an audible and visual alarm, or executing a safety shutdown procedure until the fault is cleared.
[0022] Example 2: Please refer to Figure 1 - Figure 2 As shown, a safety control method for switching multiple windings on the secondary side of a transformer includes a parameter preset module, a signal acquisition and switching module, a dual closed-loop collaborative control module, a safety interlocking and status monitoring module, and an adaptive learning unit. The parameter preset module is used to obtain the preset winding-related parameters of each winding on the secondary side of the transformer. The winding-related parameters include: target voltage setpoint, voltage transformer ratio parameters, allowable voltage fluctuation safety threshold, current fluctuation safety threshold, and preset minimum stable operating time for each winding. The signal acquisition and switching module is used to receive winding switching commands and identify the target winding number. The signal acquisition and switching module includes multiple analog input channels and high-speed digital switches, which are respectively connected to the output of the voltage transformer on each winding side. When the signal acquisition and switching module receives the switching command, it selects the corresponding channel through a high-speed digital switch to perform software switching of the feedback signal, thereby simultaneously switching the feedback channel and sending the winding-related parameters to the dual closed-loop collaborative control module. The winding-related parameters sent by the signal acquisition and switching module to the dual closed-loop collaborative control module are: the target voltage setpoint and turns ratio parameters of the corresponding target winding. The method for switching the feedback channel is as follows: switch the voltage feedback signal acquisition channel from the voltage transformer on the current winding side to the voltage transformer on the target winding side. The dual-loop collaborative control module is used to simultaneously operate the frequency phase closed loop and the voltage amplitude closed loop; The frequency and phase closed-loop method is as follows: taking the required frequency and phase of the system as a given, the voltage signal on the output side of the inverter is collected as feedback, and the frequency and phase of the modulation wave are adjusted by the first PID regulator to ensure the frequency stability of the output power supply. The method for operating the voltage amplitude closed loop is as follows: the target winding voltage given by the signal acquisition and switching module is used as the reference, and the actual voltage signal of the target winding side acquired by the signal acquisition and switching module after switching is used as the feedback. The voltage amplitude of the modulation wave is adjusted by the second PID regulator. The switching strategy of the voltage amplitude closed-loop PID controller is as follows: In the first control cycle after the switching is completed, the initial value of the integral term of the PID controller is set to the output value of the previous winding in steady state, and the proportional coefficient is reduced to suppress the voltage surge that may be generated at the moment of switching. The dual-loop collaborative control module generates the final PWM modulation wave through the combined action of the outputs of the two closed loops, driving the inverter power unit output; The safety interlock and status monitoring module is used to monitor the voltage and current feedback values on the target winding side in real time and perform threshold judgment. Based on the threshold judgment result, the protection logic is automatically triggered to perform troubleshooting operations. After the switching is completed, the safety interlock and status monitoring module starts timing. Before the minimum stable operating time of the winding is reached, non-emergency external switching commands are blocked to prevent frequent switching from damaging the transformer and frequency converter.
[0023] The adaptive learning unit records the steady-state compensation amount required by the second PID controller to reach the target voltage setpoint after each switching. After multiple switching of the same winding, the algorithm learns and fine-tunes the preset target voltage setpoint or PID parameters of the corresponding winding to further eliminate system errors and achieve more precise control.
[0024] Thresholds, preset values, or preset ranges are set for result comparison and analysis to determine whether they are good or bad. The value of these thresholds is determined by a combination of large-scale model analysis of sample data and human experience. They can also be adjusted appropriately based on seasonal or rational factors.
[0025] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A safety control method for multi-winding switching on the secondary side of a transformer, characterized in that, Includes the following steps: Step 1: Preset the target voltage setpoint, the turns ratio parameters of the voltage transformer on the secondary side of the transformer for each winding, as well as the allowable voltage fluctuation safety threshold and current fluctuation safety threshold. Step 2: When a winding switching command is received from the outside or a switching requirement is generated by the internal logic of the system, the target winding number is identified, and the feedback channel switching and parameter transmission operations are executed synchronously. Step 3: Simultaneously run the frequency phase closed loop and the voltage amplitude closed loop; Step 4: During the switching process and steady-state operation, monitor the voltage and current feedback values on the target winding side in real time and compare them with the preset safety threshold. If the monitored value exceeds the safe range, the protection logic will be triggered immediately. Step 5: The protection logic includes the following steps in sequence: freezing the switching process, locking the current output, issuing an audible and visual alarm, or executing a safety shutdown procedure until the fault is cleared.
2. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 1, characterized in that, It also includes a parameter preset module, a signal acquisition and switching module, a dual closed-loop collaborative control module, and a safety interlock and status monitoring module; The parameter preset module is used to obtain the preset winding-related parameters for each winding on the secondary side of the transformer; The signal acquisition and switching module is used to receive winding switching instructions, identify the target winding number, switch the feedback channel, and send winding-related parameters to the dual closed-loop collaborative control module. The dual-closed-loop collaborative control module is used to simultaneously operate the frequency phase closed loop and the voltage amplitude closed loop. The safety interlock and status monitoring module is used to monitor the voltage and current feedback values on the target winding side in real time, and to make threshold judgments. Based on the threshold judgment results, the protection logic is automatically triggered to perform troubleshooting operations.
3. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, The winding-related parameters obtained by the parameter preset module include: the target voltage setpoint, the transformer ratio parameters, and the allowable voltage fluctuation safety threshold and current fluctuation safety threshold.
4. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, The method for switching the feedback channel in the signal acquisition and switching module is as follows: Switch the voltage feedback signal acquisition channel from the voltage transformer on the current winding side to the voltage transformer on the target winding side; The winding-related parameters sent by the signal acquisition and switching module to the dual closed-loop collaborative control module are: the target voltage setpoint and turns ratio parameters of the corresponding target winding.
5. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, The method for the dual-closed-loop collaborative control module to operate the frequency-phase closed loop is as follows: Given the required frequency and phase of the system, the voltage signal from the output side of the inverter is collected as feedback, and the frequency and phase of the modulation wave are adjusted by the first PID regulator to ensure the frequency stability of the output power supply. The method of the dual closed-loop collaborative control module to operate the voltage amplitude closed loop is as follows: the target winding target voltage given by the signal acquisition and switching module is used as the given value, and the actual voltage signal of the target winding side acquired by the signal acquisition and switching module after switching is used as the feedback, and the voltage amplitude of the modulation wave is adjusted by the second PID regulator. The dual-closed-loop collaborative control module generates the final PWM modulation wave through the combined action of the outputs of the two closed loops, driving the inverter power unit output.
6. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, The signal acquisition and switching module includes multiple analog input channels and a high-speed digital switch, which are respectively connected to the output of the voltage transformer on each winding side. When the signal acquisition and switching module receives a switching command, it selects the corresponding channel through the high-speed digital switch to perform software switching of the feedback signal.
7. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, In the dual-loop collaborative control module, the switching strategy of the PID regulator in the voltage amplitude closed loop is as follows: in the first control cycle after the switching is completed, the initial value of the integral term of the PID regulator is set to the output value of the previous winding in steady state, and the proportional coefficient is reduced to suppress the voltage surge that may occur at the moment of switching.
8. The safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, The parameter preset module also presets the minimum stable operating time for each winding. The safety interlock and status monitoring module starts timing after the switching is completed. Before the minimum stable operating time of the winding is reached, non-urgent external switching commands are blocked.
9. A safety control method for multi-winding switching on the secondary side of a transformer according to claim 2, characterized in that, It also includes an adaptive learning unit: this unit records the steady-state compensation amount required by the second PID controller to reach the target voltage setpoint after each switch; after multiple switching of the same winding, the preset target voltage setpoint or PID parameters of the corresponding winding are finely adjusted through algorithm learning to further eliminate system errors.