Railway signal power seamless switching and wide range voltage stabilizing system suitable for mixed input

Abstract

The present application relates to the field of railway signal power supply and power electronic control technology, in particular to a seamless switching and wide range voltage stabilizing system for mixed input railway signal power supply, which is connected to the power supply bus of railway signal equipment and comprises a multi-input module, a fast switching module, a voltage stabilizing module and a switching control module; the switching control module obtains the electrical parameters of each input branch and the real-time load state of the power supply bus according to preset sampling time intervals, obtains the dynamic drop threshold, voltage effective value drop rate and voltage change rate, performs failure prediction, and outputs switching instructions and transient support enable signals when the trigger conditions are met; the fast switching module disconnects the mains input branch and connects the standby power supply branch, the voltage stabilizing module outputs compensation power, and the switching control module generates steady-state power distribution parameters and outputs operation data after voltage recovery; the present application reduces power supply interruption and voltage collapse problems.

Description

Technical Field

[0001] This invention relates to the field of railway signal power supply and power electronic control technology, specifically to a seamless switching and wide-range voltage regulation system for railway signal power supplies with mixed inputs. Background Technology

[0002] As a key power-consuming object to ensure the safe operation of trains, the continuity of power supply and the stability of bus voltage of railway signaling equipment are directly related to whether the equipment can work continuously and reliably in the station interlocking, train control center and signaling system along the line. Therefore, achieving rapid switching and stable power supply when the input power fluctuates or fails is an important foundation for ensuring the safe operation of the system. Existing railway signal power switching schemes still have many problems. For example, they mostly adopt a passive switching method between mains power and backup power. Switching is usually only performed after the voltage drop exceeds the preset limit or even after the power supply is interrupted. This can easily cause power outages and severe voltage drops on the bus during the switching interval. It is also difficult to coordinate the power supply of multiple inputs such as traction feedback and new energy sources. Especially when the load changes rapidly, the ambient temperature difference is large, and the performance of the devices degrades over a long period of time, the existing schemes are still unable to achieve unified control of transient compensation, energy storage recharge, temperature regulation, and health warning. They cannot effectively meet the requirements of railway signaling equipment for continuous power supply and wide voltage stabilization. Summary of the Invention

[0003] The purpose of this invention is to provide a seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs, addressing the following technical problems: Existing railway signal power supply switching schemes are prone to passive switching in the face of power fluctuations or failures, leading to power supply gaps and bus voltage collapse. Furthermore, they have technical limitations in the unified control of multi-input coordinated power supply, transient compensation, temperature regulation, and health warning. Therefore, there is an urgent need for a seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs, aiming to achieve early seamless switching and transient power compensation during dead time based on failure prediction, effectively coordinate multi-source power distribution, and possess thermal management and health status monitoring functions. The purpose of this invention can be achieved through the following technical solutions: A seamless switching and wide-range voltage regulation system for railway signal power supplies with mixed inputs is provided. The system is connected to the power supply bus of railway signal equipment and includes: a multi-input module, a fast switching module, a voltage regulation module, and a switching control module. The multi-input module includes a mains input branch and a backup power branch; wherein, both the mains input branch and the backup power branch are connected in series with a power converter with power regulation capability, which is used to receive control commands and continuously adjust the output current of the branch. The voltage regulator module includes an energy storage unit and a bidirectional DC-DC converter connected to the energy storage unit; The switching control module is configured to: acquire the electrical parameters of each input branch in the multi-input module and the real-time load status of the power supply bus of the railway signaling equipment at a preset sampling time interval; obtain the dynamic drop threshold, voltage effective value drop rate, and voltage change rate based on the electrical parameters and real-time load status of each input branch; perform failure prediction based on the voltage effective value drop rate, voltage change rate, and dynamic drop threshold; and output a switching command and transient support enable signal when the voltage effective value drop rate and voltage change rate meet the preset trigger conditions. The fast switching module is configured to disconnect the mains input branch and connect the backup power branch according to the switching command; The voltage stabilizing module is configured to output compensated power to the power supply bus of the railway signaling equipment according to the transient support enable signal; The switching control module is also configured to: detect the voltage recovery status of the power supply bus of the railway signaling equipment, generate steady-state power distribution parameters to control the multi-input module to perform power distribution, the steady-state power distribution parameters specifically being the current reference commands for controlling the power converters in each input branch, and summarizing the system operation data and outputting it to an external maintenance terminal.

[0004] Optionally, the electrical parameters and real-time load status of each input branch are as follows: The electrical parameters of each input branch include at least the electrical parameters of the mains input branch, which include: the instantaneous voltage of the mains input branch, the output current of the mains input branch, and the effective value of the rated voltage of the mains input branch. The real-time load status includes: the real-time voltage of the railway signaling equipment power supply bus, the real-time current of the railway signaling equipment power supply bus, and the design maximum rated power of the railway signaling equipment power supply bus.

[0005] Optionally, the specific configuration for failure prediction by the switching control module is as follows: The real-time load power is obtained based on the real-time voltage and real-time current of the power supply bus of the railway signaling equipment, and the dynamic sag threshold is determined in combination with the design maximum rated power, the preset basic sag threshold and the load sensitivity coefficient; the voltage effective value sag rate is obtained based on the instantaneous voltage and rated voltage effective value of the mains input branch, and the voltage change rate is obtained based on the change of instantaneous voltage over time; it is determined whether the voltage effective value sag rate is greater than the dynamic sag threshold and the duration exceeds a preset time window, and whether the voltage change rate is greater than a preset change rate limit threshold; If the effective voltage drop rate is greater than the dynamic drop threshold and the duration exceeds a preset time window, or if the voltage change rate is greater than a preset change rate limit threshold, then it is determined that the mains input branch is about to fail, the preset triggering condition is met, and the switching command and the transient support enable signal are output. Otherwise, if the mains input branch is deemed normal, the switching command will not be output.

[0006] Optionally, the switching control module has a built-in operation control strategy, which includes: a multi-source allocation strategy, a transient support strategy, an energy recharge strategy, and a thermal management strategy.

[0007] Optionally, the backup power supply branch includes a traction feedback input branch and a distributed renewable energy input branch; the multi-source allocation strategy is as follows: When the power supply bus of the railway signaling equipment is in a steady-state power supply stage, the available traction feedback power of the traction feedback input branch and the available distributed new energy power of the distributed new energy input branch are obtained first. The specific methods for obtaining the available traction feedback power and the available distributed new energy power are: receiving the available power data transmitted in real time from the corresponding external power generation system through the communication bus inside the system, or obtaining it based on the open circuit voltage and maximum rated output current of the corresponding input branch side. When the sum of the available power of traction feedback and the available power of distributed new energy is greater than or equal to the real-time load power, the fast switching module is controlled to disconnect the mains input branch according to the preset rated capacity ratio, and the backup power branch supplies power independently. When the sum of the available power of traction feedback and the available power of distributed new energy is less than the real-time load power, the mains input branch is connected to make up the difference in power.

[0008] Optionally, the transient support strategy is: Upon receiving the switching command, the bidirectional DC-DC converter in the voltage regulator module switches from standby mode to boost discharge mode; When the fast switching module is in the dead zone between the disconnection of the mains input branch and the closure of the backup power branch, it limits the voltage fluctuation of the railway signal equipment power supply bus to a preset voltage fluctuation range, and outputs a preset peak power to the railway signal equipment power supply bus through dual closed-loop control of voltage outer loop and current inner loop to compensate for the bus voltage gap.

[0009] Optionally, the energy recharge strategy is as follows: When the backup power supply branch is fully connected and the voltage of the railway signal equipment power supply bus is greater than or equal to the preset rated voltage of the power supply bus, the bidirectional DC converter in the voltage regulator module exits the boost discharge mode and enters the buck charging mode. The remaining power of the backup power branch is used to charge the energy storage unit in the voltage regulator module; charging stops when the terminal voltage of the energy storage unit returns to the rated energy storage voltage.

[0010] Optionally, the voltage regulator module further includes a semiconductor temperature control component attached to the surface of the energy storage unit, and the thermal management strategy is as follows: Set the preset antifreeze temperature threshold to be lower than the preset heat dissipation temperature threshold; When the surface temperature of the energy storage unit is lower than the antifreeze temperature threshold, the heating mode of the semiconductor temperature control component is triggered; When the surface temperature of the energy storage unit is higher than the heat dissipation temperature threshold, the cooling mode of the semiconductor temperature control component is triggered. When the surface temperature of the energy storage unit is greater than or equal to the antifreeze temperature threshold and less than or equal to the heat dissipation temperature threshold, the control semiconductor temperature control component is in standby mode.

[0011] Optionally, the backup power supply branch includes a distributed new energy input branch for connecting to new energy power, and a traction feedback input branch for connecting to train feedback energy; The fast switching module includes multiple sets of solid-state switches connected in series between the multi-input module and the power supply bus of the railway signaling equipment, used to realize the conduction and isolation of each input branch; The energy storage unit is connected in parallel to the power supply bus of the railway signaling equipment, and the bidirectional DC-DC converter connects the energy storage unit and the power supply bus. The switching control module includes a high-speed digital signal processor for real-time acquisition of electrical parameters of each input branch.

[0012] Optionally, it may also include a health warning module; The health warning module is used to continuously record the turn-on delay time of the solid-state switch and the voltage drop slope of the energy storage unit during each switching process. When the solid-state switch turn-on delay is detected to increase three times consecutively and exceed the preset delay threshold, or when the voltage rise rate of the energy storage unit under the preset constant current charging condition is lower than the preset proportion of the preset calibration value, an early warning signal is generated and reported to the external maintenance terminal through the communication interface to prompt equipment maintenance; otherwise, the system is kept in normal operating status.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This system predicts failure by calculating dynamic drop thresholds and other indicators based on real-time load status and electrical parameters, and outputs switching commands in advance before the mains power is completely cut off; during the dead time between the mains power disconnection and the backup power supply closing, the voltage regulator module outputs compensation power to fill the power gap, effectively avoiding the power interruption and severe voltage drop problems caused by traditional passive switching, and ensuring the continuous operation of signal equipment. 2. This system has a built-in multi-source allocation strategy. During the steady-state phase, it prioritizes the use of traction feedback and available power from distributed new energy sources. When the power is insufficient, it connects to the mains power to make up the difference, thus realizing the coordinated control of multiple inputs. At the same time, it is combined with an energy recovery and charging strategy to use the remaining power of the backup power supply to charge the energy storage unit in a timely manner, ensuring that the energy storage state is restored after each support action, thus ensuring that the system has the ability to continuously cope with transient power fluctuations. 3. By controlling the heating or cooling mode of the semiconductor temperature control component through thermal management strategies, the energy storage unit can maintain normal discharge capability in extreme temperature environments. In addition, the health warning module continuously records the solid-state switch turn-on delay time and the voltage change of the energy storage unit. It can generate warning signals and report to the maintenance terminal in the early stage of device performance degradation, realizing the transformation from passive emergency repair to predictive maintenance. Attached Figure Description

[0014] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of a module for a railway signal power supply seamless switching and wide-range voltage regulation system suitable for mixed inputs, provided in an embodiment of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0016] like Figure 1 As shown, a seamless switching and wide-range voltage regulation system for railway signal power supply suitable for mixed inputs is provided. The system is connected to the power supply bus of railway signal equipment and includes: a multi-input module, a fast switching module, a voltage regulation module, and a switching control module. The multi-input module includes a mains input branch and a backup power branch; both the mains input branch and the backup power branch are connected in series with a power converter with power regulation capability, which is used to receive control commands and continuously adjust the output current of the branch. The voltage regulator module includes an energy storage unit and a bidirectional DC-DC converter connected to the energy storage unit; The switching control module is configured to: acquire the electrical parameters of each input branch in the multi-input module and the real-time load status of the power supply bus of the railway signaling equipment at preset sampling time intervals; obtain the dynamic drop threshold, voltage effective value drop rate, and voltage change rate based on the electrical parameters and real-time load status of each input branch; perform failure prediction based on the voltage effective value drop rate, voltage change rate, and dynamic drop threshold; and output a switching command and transient support enable signal when the voltage effective value drop rate and voltage change rate meet the preset trigger conditions. The fast switching module is configured to disconnect the mains input branch and connect the backup power branch according to the switching command; The voltage regulator module is configured to output compensated power to the power supply bus of the railway signaling equipment based on the transient support enable signal; The switching control module is also configured to: detect the voltage recovery status of the power supply bus of the railway signaling equipment, generate steady-state power distribution parameters to control the multi-input module to perform power distribution, specifically the steady-state power distribution parameters are the current reference commands for controlling the power converters in each input branch, and summarize the system operation data and output it to the external maintenance terminal.

[0017] In this embodiment, the system is installed at the front end of the power supply bus of the railway signaling equipment. The power supply bus serves as the unified power source for the microcomputer interlocking, train control center, and other signaling equipment. A multi-input module is used to connect to power from different sources, including at least a mains input branch and a backup power branch. A fast switching module is connected in series between the multi-input module and the power supply bus, handling the connection and disconnection of each branch. A voltage stabilizing module is connected in parallel to the power supply bus, remaining in standby mode during non-transient support periods and replenishing power to the bus during switching. The switching control module is the core of the entire system, internally equipped with a high-speed digital signal processor. A sampling frequency of at least 10kHz is preferred, with a corresponding sampling time interval of 0.1ms. During system operation, the prerequisites are that all input branches are connected and the power supply bus is under load. The switching control module continuously collects electrical parameters of the mains input branch and the backup power branch at 0.1ms intervals, and simultaneously collects the real-time voltage and real-time current of the power supply bus. After the sampled data enters the control program, it first calculates the dynamic drop threshold, and then calculates the voltage effective value drop rate and voltage change rate of the mains input branch. If it is determined that the mains power meets the preset failure triggering conditions, the switching control module outputs two types of signals at the same time: one is a switching command sent to the fast switching module, and the other is a transient support enable signal sent to the voltage regulator module. After receiving the switching command, the fast switching module first disconnects the mains input branch and then connects the backup power branch. Because there is a dead time between the two actions, the voltage regulator module outputs compensation power to the power supply bus via the bidirectional DC-DC converter during this downtime to prevent the bus voltage drop from exceeding the preset limit. After the backup power branch is stably connected, the switching control module continues to detect whether the power supply bus voltage has recovered to the rated power supply range. As long as the bus voltage is detected to have recovered, the switching control module generates steady-state power allocation parameters, which are used to control the multi-input module to allocate the power supply share between the mains power and the backup power. At the same time, the system will summarize the operating data such as switching time, bus voltage fluctuation, current of each branch and working status of energy storage unit and send it to the external maintenance terminal for maintenance personnel to view. The direct technical effect of this configuration is that it integrates failure judgment, switching execution and transient compensation into the same control sequence, thereby reducing the risk of power interruption and severe voltage drop that are common when switching traditional mechanical relays. As an example, suppose the rated voltage of the signal power supply bus of a railway station is a fixed value and the system is operating stably. The switching control module collects data every 0.1ms. When the mains input branch shows a rapid drop trend, the control module first identifies the decrease in the effective voltage value and the acceleration of instantaneous voltage change from the sampled data, and then determines that the trigger condition is met. At this time, the fast switching module starts to perform the action of switching from mains power to standby, while the voltage stabilizing module starts to discharge compensation at the same time. In this way, the power supply bus can still maintain the continuous operation of signal equipment before the backup power supply is fully turned on. This process targets objective electrical quantities, including branch voltage, branch current, bus voltage, bus current and load power. Ultimately, it improves the continuity and voltage stability of the power supply bus and is a clear power control technology solution. In this embodiment, the electrical parameters and real-time load status of each input branch are as follows: The electrical parameters of each input branch shall include at least the electrical parameters of the mains input branch, which shall include: the instantaneous voltage of the mains input branch, the output current of the mains input branch, and the effective value of the rated voltage of the mains input branch. Real-time load status includes: real-time voltage of the railway signaling equipment power supply bus, real-time current of the railway signaling equipment power supply bus, and the maximum rated power of the railway signaling equipment power supply bus.

[0018] In this embodiment, the content collected in the examples is further defined; the instantaneous voltage of the mains input branch refers to the instantaneous value of the mains input branch voltage read by the switching control module at each sampling moment; the output current of the mains input branch is the actual current value sent to the system by the mains input branch at the same sampling moment; the effective value of the rated voltage of the mains input branch is the reference voltage value used as the judgment criterion; the real-time voltage and real-time current of the railway signal equipment power supply bus in the real-time load state directly reflect the current actual power consumption of the railway signal equipment; The maximum rated power of the power supply busbar for railway signaling equipment is the upper limit of the power that the busbar is allowed to carry for a long time during the design, which is used to calculate the current load ratio. During operation, the switching control module first receives the instantaneous voltage and output current of the mains input branch from the voltage and current sampling circuit, and then receives the real-time voltage and real-time current of the power supply busbar for railway signaling equipment from the busbar sampling circuit. The program calculates the real-time load power by multiplying the real-time voltage of the railway signaling equipment power supply bus by the real-time current, and compares this real-time load power with the design maximum rated power to obtain the current load ratio; the load ratio serves as the direct input parameter for subsequent calculation of the dynamic drop threshold. As an example, assuming that the real-time voltage of the railway signaling equipment power supply bus is within the preset rated voltage tolerance range at a certain moment, and the real-time load power corresponding to the real-time current is 60% of the design maximum rated power, then the switching control module has already acquired five types of basic data: the instantaneous voltage of the mains input branch, the output current of the mains input branch, the real-time voltage of the railway signaling equipment power supply bus, the real-time current of the railway signaling equipment power supply bus, and the design maximum rated power of the railway signaling equipment power supply bus. Subsequently, whether calculating the dynamic drop threshold or judging whether there is a risk of failure in the mains input branch, it is all based directly on these real sampled quantities. The technical advantage of limiting the sampling objects in this way is that all judgments are based on measurable objective electrical quantities, which facilitates on-site reproduction and improves the measurability of the system and the traceability of the operation process. In this embodiment, the specific configuration for switching the control module to perform failure prediction is as follows: Real-time load power is obtained based on the real-time voltage and real-time current of the power supply bus of railway signaling equipment, and dynamic sag threshold is determined by combining the design maximum rated power, preset basic sag threshold and load sensitivity coefficient; voltage effective value sag rate is obtained based on the instantaneous voltage and rated voltage effective value of the mains input branch, and voltage change rate is obtained based on the change of instantaneous voltage over time; it is determined whether the voltage effective value sag rate is greater than the dynamic sag threshold and the duration exceeds the preset time window, and whether the voltage change rate is greater than the preset change rate limit threshold. If the effective voltage drop rate is greater than the dynamic drop threshold and the duration exceeds the preset time window, or if the voltage change rate is greater than the preset change rate limit threshold, then the mains input branch is determined to be about to fail, the preset triggering condition is met, and a switching command and transient support enable signal are output. Otherwise, the mains input branch is deemed normal, and no switching command is output.

[0019] In this embodiment, the failure prediction of the switching control module is executed in a preset order. First, the switching control module calculates the real-time load power based on the real-time voltage and real-time current of the power supply bus, by multiplying the two. Second, the dynamic drop threshold is calculated using the ratio of the real-time load power to the maximum rated power. The basic drop threshold is preferably set to 8% of the rated voltage of the power supply bus, and the load sensitivity coefficient is preferably between 0.02 and 0.05, which can be obtained through factory load test calibration. Specifically, the dynamic drop threshold is equal to the base drop threshold minus the product of the load sensitivity coefficient and the load ratio. The reason for this configuration is that the heavier the load, the more sensitive the bus is to voltage fluctuations, and the system should prepare for switching earlier. The third step is that the switching control module performs half-wave integration on the instantaneous voltage of the mains input branch to obtain the real-time effective value. Specifically, for a 50Hz mains power supply, the half-wave period corresponds to 10ms. With a sampling interval of 0.1ms, the control module extracts the most recent 100 historical instantaneous voltage sampling points, including the current time, at each sampling moment and performs discrete integration. The calculation process involves first calculating the average of the squares of the voltages at these 100 sampling points, and then taking the square root, thereby outputting the real-time effective value within the current half-wave period in real time. This processing method does not rely on complex nonlinear models and can accurately reflect the voltage drop trend with the delay required to meet the dynamic response requirements of the system. Next, divide the difference between the rated voltage RMS value and the real-time RMS value by the rated voltage RMS value to obtain the voltage RMS drop rate in the current period; the fourth step is to switch the control module to read the instantaneous mains voltage of the current sampling period and the previous sampling period, calculate the difference, and then divide it by the sampling time interval to obtain the voltage change rate; the fifth step is to determine the program execution conditions. First, it determines whether the effective voltage drop rate exceeds the dynamic drop threshold and whether this over-threshold condition persists for more than a preset time window. Second, it determines whether the voltage change rate exceeds a preset change rate limit threshold. The preset time window is preferably 0.3ms, corresponding to three consecutive sampling cycles at 10kHz sampling. The change rate limit threshold is preferably 150V / ms. If either of the above two determinations is true, the switching control module determines that the mains input branch is about to fail and simultaneously outputs a switching command and a transient support enable signal. If neither of the two determinations is true, the mains input branch remains in normal condition and no switching command is issued. As an example, assuming the base drop threshold is 8%, the load sensitivity coefficient is 0.03, and the current real-time load power accounts for 50% of the maximum rated power, then the dynamic drop threshold is 8% minus 0.03 multiplied by 50%, which is approximately 6.5%. Further assuming the calculated effective value drop rate of the mains voltage is 7%, and it has been continuous for 0.3ms, then 7% is greater than 6.5%, the condition is met, and the system immediately enters the switching preparation. To give another example, if the effective voltage drop rate does not reach the dynamic drop threshold, but the instantaneous mains voltage difference between two adjacent 0.1ms sampling points already corresponds to a change rate of 160V / ms, since 160V / ms is greater than 150V / ms, the system will immediately trigger a switch. Thus, this implementation does not wait for the mains power to be completely interrupted before performing the action, but switches in advance when the voltage has already shown an irreversible drop trend, thereby providing more ample response time margin for the fast switching module and the voltage regulation module. In this embodiment, the switching control module has a built-in operation control strategy, which includes: multi-source allocation strategy, transient support strategy, energy recharge strategy, and thermal management strategy.

[0020] In this embodiment, the switching control module is not only responsible for failure prediction and switching command output, but also has four built-in operation control strategies: multi-source allocation strategy for power arrangement during steady-state power supply; transient support strategy for bus compensation during switching; energy recovery strategy for restoring energy storage unit energy after switching; and thermal management strategy for ensuring that energy storage unit can still work stably in cold and hot environments along the line. The four strategies are all executed by the switching control module, and the execution targets are the multi-input module, the fast switching module, the bidirectional DC-DC converter, and the semiconductor temperature control component, respectively. In terms of the execution sequence, the system first determines whether a switch is needed based on failure prediction. If no switch is needed, the multi-source allocation strategy is executed first. If a switch is needed, the transient support strategy and the fast switching action are executed first. After the backup power branch is fully connected, the energy recovery strategy is executed. The system executes the thermal management strategy in parallel at all times. This setting ensures that each strategy has clear triggering conditions and execution results, thereby ensuring the clarity of the controlled object and the accuracy of the execution sequence. In this embodiment, the backup power supply branch includes a traction feedback input branch and a distributed renewable energy input branch; the multi-source allocation strategy is as follows: When the power supply bus of the railway signaling equipment is in a steady-state power supply stage, priority is given to obtaining the available traction feedback power of the traction feedback input branch and the available distributed new energy power of the distributed new energy input branch. The specific methods for obtaining the available traction feedback power and the available distributed new energy power are: receiving the available power data transmitted in real time from the corresponding external power generation system through the communication bus inside the system, or obtaining it based on the open circuit voltage and maximum rated output current of the corresponding input branch side. When the sum of the available power of traction feedback and the available power of distributed new energy is greater than or equal to the real-time load power, the fast switching module is controlled to disconnect the mains input branch according to the preset rated capacity ratio, and the backup power branch supplies power independently. When the sum of the available power of traction feedback and the available power of distributed new energy is less than the real-time load power, the mains input branch is connected to make up the difference in power.

[0021] In this embodiment, the backup power supply branch consists of a traction feedback input branch and a distributed new energy input branch; the traction feedback input branch receives traction feedback power during train braking or operation, and the distributed new energy input branch receives distributed new energy power along the line, such as solar or wind power; the steady-state power supply stage refers to the stage where the voltage of the railway signal equipment power supply bus has returned to stability and the system is not in the switching dead zone. After entering the steady-state power supply stage, the switching control module first reads the available traction feedback power of the traction feedback input branch and the available distributed renewable energy power of the distributed renewable energy input branch, and then compares it with the real-time load power. If the sum of the available traction feedback power and the available distributed renewable energy power is greater than or equal to the real-time load power, it means that the distributed renewable energy and traction feedback power are sufficient to supply power independently. At this time, the switching control module controls the fast switching module to disconnect the mains input branch according to the preset rated capacity ratio, and the backup power branch supplies power independently. The rated capacity ratio here refers to the power share undertaken by the traction feedback input branch and the distributed new energy input branch according to their respective rated capacities. If the sum of the available power of traction feedback and the available power of distributed new energy is less than the real-time load power, the switching control module maintains or reconnects the mains input branch, and the mains input branch makes up the difference in power. The direct effect of this configuration is to give priority to the use of recyclable and renewable energy, while ensuring that the railway signaling equipment does not lose power when the power of the backup power branch is insufficient. As an example, suppose at a certain moment the real-time load power is 10kW, the available traction feedback power is 4kW, and the available distributed renewable energy power is 7kW, totaling 11kW, which is no less than 10kW. In this case, the switching control module controls the fast switching module to disconnect the mains input branch, and only the backup power branch provides power. Now suppose at another moment the real-time load power is still 10kW, but the available traction feedback power drops to 3kW, and the available distributed renewable energy power is 2kW, totaling only 5kW. In this case, the switching control module connects the mains input branch, and the mains input branch makes up the remaining 5kW difference in power. The multi-source allocation strategy directly affects the actual power allocation, ultimately manifesting as changes in the current of each input branch and changes in the power supply path of the railway signaling equipment power supply bus. In this embodiment, the transient support strategy is as follows: Upon receiving the switching command, the bidirectional DC-DC converter in the voltage regulator module switches from standby mode to boost discharge mode; When the fast switching module is in the dead zone between the disconnection of the mains input branch and the closure of the backup power branch, it limits the voltage fluctuation of the railway signal equipment power supply bus to a preset voltage fluctuation range, and outputs a preset peak power to the railway signal equipment power supply bus through dual closed-loop control of voltage outer loop and current inner loop to compensate for the bus voltage gap.

[0022] In this embodiment, the transient support strategy is specifically designed to address the short-term power supply gap that exists during the rapid switching process. The triggering condition is that the switching control module has determined that the mains input branch is about to fail and has issued a switching command. At the same time as the switching command is issued, the bidirectional DC-DC converter switches from standby mode to boost discharge mode. At this time, the rapid switching module is performing the actions of disconnecting the mains input branch and closing the backup power branch, and there is a dead time between the two actions. To prevent the bus voltage from dropping too quickly during the dead time, the bidirectional DC-DC converter boosts the electrical energy stored in the energy storage unit and sends it to the power supply bus. The control method adopts a control structure of voltage outer loop and current inner loop. The outer loop takes the rated voltage of the power supply bus as the given value and determines the required compensation level according to the difference between the actual voltage of the bus and the rated value. The inner loop adjusts the output current according to the target given by the outer loop. Specifically, during the dead zone between the mains power disconnection and the backup power supply not being fully closed, the external power supply to the bus is interrupted, and the voltage change rate exceeds the preset threshold, causing the outer loop voltage difference to increase rapidly within the preset time period, which causes the inner loop current reference value to reach the system's set saturation control upper limit within a sub-millisecond time. Therefore, during the entire dead time gap, the dual closed-loop system operates in a saturated state, driving the converter to continuously provide power support to the bus according to the system's maximum output capacity, i.e., the preset peak power. This operating mechanism based on large deviation saturated output peak power can compensate for the bus power gap caused by power supply interruption according to the preset response rate and power demand, preventing further voltage deterioration. Once the backup power supply is connected, the bus voltage recovers, and the voltage difference narrows, the outer loop will automatically exit the saturation state and resume linear dynamic adjustment, thereby limiting the final voltage fluctuation of the power supply bus to within ±5% of the rated value. The energy storage unit capacity is preferably configured to provide short-term high-power charging and discharging to fully meet the constant peak power discharge requirements during the dead time. In this setup, the fast switching module is responsible for changing the power supply path, and the voltage stabilizing module is responsible for filling the power gap during path switching. The two parts work together to ensure that sensitive signal equipment does not restart due to instantaneous voltage drop. As an example, suppose the system has issued a switching command, but there is a gap of several milliseconds before the backup power branch is fully turned on; at this time, the actual bus voltage drops at a rate exceeding the preset rate of change, the difference calculated by the outer loop increases rapidly, and the system's dual closed loop immediately enters saturation state and directly outputs the preset peak power for compensation, so that the bus voltage is maintained within the allowable fluctuation range and does not collapse deeply; after the backup power is fully turned on, the outer loop difference decreases and linear regulation is restored, the bus power supply returns to the normal range, and the transient support ends smoothly. In this embodiment, the energy recharge strategy is as follows: When the backup power supply branch is fully connected and the voltage of the railway signal equipment power supply bus is greater than or equal to the preset rated voltage of the power supply bus, the bidirectional DC converter in the voltage regulator module exits the boost discharge mode and enters the buck charging mode. The remaining power of the backup power branch is used to charge the energy storage unit in the voltage regulator module; charging stops when the terminal voltage of the energy storage unit returns to the rated energy storage voltage.

[0023] In this embodiment, the energy recovery strategy occurs after the switching is completed. There are two prerequisites: first, the backup power branch has been fully connected; second, the power supply bus voltage has been restored to no less than the rated voltage. After these two conditions are met, the switching control module sends a mode switching command to the bidirectional DC-DC converter, causing it to exit the boost discharge mode and enter the buck charging mode. At this time, if the backup power branch still has residual power after meeting the real-time load power, the residual power is stepped down by the bidirectional DC-DC converter and sent to the energy storage unit for recharging; the switching control module continuously reads the terminal voltage of the energy storage unit, and when it detects that the terminal voltage has recovered to the rated energy storage voltage, it immediately stops charging and puts the energy storage unit back into the standby energy storage state; this configuration is designed to restore the energy storage unit in a timely manner after each support action, so as to ensure that there is still sufficient transient support capability during the next switch. As an example, suppose that the energy storage unit has released some electrical energy during a switching process. After the backup power branch is connected, the power supply bus returns to stability. At this time, the bidirectional DC-DC converter switches to charging operation. If the backup power supply still has a margin after handling the current load, this margin is used to charge the energy storage unit. When the terminal voltage returns to the rated energy storage level, the switching control module ends the recharge process and stops charging. The entire process is based on closed-loop control of real-time voltage and power changes, ultimately achieving the technical goal of restoring the energy storage unit to a usable state. In this embodiment, the voltage regulator module also includes a semiconductor temperature control component attached to the surface of the energy storage unit, and the thermal management strategy is as follows: Set the preset antifreeze temperature threshold to be lower than the preset heat dissipation temperature threshold; When the surface temperature of the energy storage unit is lower than the antifreeze temperature threshold, the heating mode of the semiconductor temperature control component is triggered; When the surface temperature of the energy storage unit exceeds the heat dissipation temperature threshold, the cooling mode of the semiconductor temperature control component is triggered. When the surface temperature of the energy storage unit is greater than or equal to the antifreeze temperature threshold and less than or equal to the heat dissipation temperature threshold, the control semiconductor temperature control component is in standby mode.

[0024] In this embodiment, the thermal management strategy is used to ensure that the energy storage unit remains usable in low-temperature and high-temperature environments along the railway line. The semiconductor temperature control component is directly attached to the surface of the energy storage unit, and the switching control module reads the surface temperature of the energy storage unit in real time. Preferably, the antifreeze temperature threshold can be set to 0°C, and the heat dissipation temperature threshold can be set to 50°C, with the former being less than the latter. If the surface temperature of the energy storage unit is detected to be below 0°C, the switching control module triggers the heating mode of the semiconductor temperature control component to reduce the decrease in discharge capacity caused by the increase in equivalent series resistance at low temperatures. If the surface temperature is detected to be above 50°C, the cooling mode is triggered to avoid the adverse effects of high temperature on the energy storage status and lifespan. If the surface temperature is between 0°C and 50°C, the semiconductor temperature control component remains in standby mode. The significance of this configuration is that the voltage regulator module must not only be able to discharge during switching, but also provide stable transient power under different climatic conditions throughout the year; As an example, when the temperature inside the equipment box along the line drops to -5°C at night in winter, the switching control module detects that the temperature is below the antifreeze temperature threshold and triggers the heating mode to bring the energy storage unit back to the temperature range suitable for discharge. In summer, under direct sunlight, if the temperature inside the equipment box rises to 55°C, the system will start the cooling mode. If the surface temperature remains at around 25°C in spring and autumn, the semiconductor temperature control component will be in standby mode to reduce the additional energy consumption of the system. In this embodiment, the backup power supply branch includes a distributed new energy input branch for connecting to new energy sources, and a traction feedback input branch for connecting to train feedback energy. The fast switching module includes multiple sets of solid-state switches connected in series between the multi-input module and the power supply bus of the railway signaling equipment, which are used to enable the conduction and isolation of each input branch; The energy storage unit is connected in parallel to the power supply bus of the railway signaling equipment, and the bidirectional DC-DC converter connects the energy storage unit to the power supply bus. The switching control module includes a high-speed digital signal processor for real-time acquisition of electrical parameters of each input branch.

[0025] In this embodiment, the system hardware connection relationship is further explained; the backup power supply branch consists of two parts: one part is a distributed new energy input branch, used to connect to new energy power along the line; the other part is a traction feedback input branch, used to connect to train feedback energy; the fast switching module consists of multiple sets of solid-state switches, which are connected in series between the multi-input module and the power supply bus of the railway signaling equipment, and each input branch corresponds to one or more sets of solid-state switches; the switching control module controls the solid-state switches to turn on or off to realize the access and isolation of each input branch; Compared with traditional mechanical relays, solid-state switches are more suitable for railway signal power supply scenarios with millisecond-level action requirements. Solid-state switches are preferably composed of anti-parallel thyristors or insulated gate bipolar transistor power devices with high bidirectional blocking capability. When a switching command is issued, the original power supply branch can be quickly shut off and the new power supply branch can be turned on within hundreds of microseconds. At the same time, due to the hard isolation characteristics of solid-state switches, transient short-circuit currents between different power supplies can be effectively prevented. With the transient support of the energy storage unit at the hardware level, seamless power switching can be achieved. The energy storage unit is directly connected in parallel to the power supply bus. The bidirectional DC-DC converter is arranged between the energy storage unit and the power supply bus, and is responsible for switching between the two states of discharge support and recharge energy storage. The high-speed digital signal processor in the switching control module undertakes the tasks of sampling, calculation and command issuance. The preferred sampling frequency is not less than 10kHz, so as to meet the sampling speed requirements of the aforementioned dynamic threshold calculation and failure prediction. After the above hardware connection relationship is determined, the data flow and energy flow are also clear. That is, electrical parameters are sent to the switching control module from each input branch and the power supply bus, control commands are sent to the solid-state switch and the bidirectional DC-DC converter from the switching control module, and energy is sent to the power supply bus from the selected input branch and the energy storage unit. In this embodiment, a health warning module is also included; The health warning module is used to continuously record the turn-on delay time of the solid-state switch and the voltage drop slope of the energy storage unit during each switching process. When the solid-state switch turn-on delay is detected to increase three times consecutively and exceed the preset delay threshold, or when the voltage rise rate of the energy storage unit under the preset constant current charging condition is detected to be lower than the preset proportion of the preset calibration value, an early warning signal is generated and reported to the external maintenance terminal through the communication interface to prompt equipment maintenance; otherwise, the normal operating status of the system is maintained.

[0026] In this embodiment, the health warning module is used to track the status changes of the fast switching module and the voltage regulation module over a long period of time. It records two types of data: the turn-on delay time of the solid-state switch during each switching process and the voltage drop slope of the energy storage unit. The turn-on delay time reflects the time change between receiving the control command and the actual turn-on of the solid-state switch; the voltage drop slope reflects the rate of voltage decrease of the energy storage unit during the supporting discharge process. Specifically, the calculation method is as follows: read the voltage difference between the starting and ending times of the energy storage unit during a single supporting discharge phase, and divide this voltage difference by the corresponding supporting discharge duration. Each time the system completes a switch, the health warning module saves the recorded value and compares it with the previous records. If the solid-state switch turn-on delay is detected to increase three times in a row and exceed the preset delay threshold, it indicates that the solid-state switch's operating performance may be deteriorating. The preset delay threshold can preferably be set to 1ms. In addition, in order to comprehensively assess the health status, the health warning module records the voltage drop slope during the energy storage unit's support discharge to assess the transient output capability, and records the voltage rise rate of the energy storage unit under preset constant current charging conditions to assess the aging degree of the energy storage unit; the preset calibration value is the benchmark value of the energy storage unit's voltage rise rate measured under exactly the same constant current charging conditions when the equipment leaves the factory or when the system is in the initial health state. If the voltage rise rate of the energy storage unit under the preset constant current charging condition is lower than the preset percentage of the preset calibration value, it indicates that its energy storage performance may decline. The preset percentage can preferably be set to 80%. As long as either of the above two situations is true, the health warning module will generate a warning signal and report it to the external maintenance terminal to prompt the arrangement of equipment maintenance. If neither of the two situations occurs, the system will maintain the normal operating status. As an example, suppose that during three consecutive switching operations, the conduction delay time of a certain group of solid-state switches in the fast switching module increases sequentially, and the latest value has exceeded 1ms. Then, the health warning module will generate a warning signal immediately after the third recording is completed. Furthermore, suppose that when the energy storage unit is tested under the preset constant current charging condition during the energy recovery phase, the measured voltage rise rate is only 75% of the preset calibration value. Since 75% is lower than the preset ratio of 80%, a warning signal will also be triggered. The technical advantage of this configuration is that it can prevent the system from passively responding after a power switching failure and enable the output of maintenance warning signals in the early stages of device performance degradation. The health warning module still processes clear and objective physical quantities such as the solid-state switch turn-on delay time, the voltage drop slope of the energy storage unit supporting discharge, and the voltage rise rate under constant current charging conditions. This unifies the full-cycle parameters of the energy storage unit and switching devices in the working sequence, and the ultimate goal is to ensure the success rate of power switching and the voltage regulation capability of the power supply bus of railway signaling equipment.

[0027] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A seamless switching and wide-range voltage regulation system for railway signal power supplies with mixed inputs, characterized in that, The system is connected to the power supply bus of railway signaling equipment and includes: a multi-input module, a fast switching module, a voltage stabilizing module, and a switching control module; The multi-input module includes a mains input branch and a backup power branch; wherein, both the mains input branch and the backup power branch are connected in series with a power converter with power regulation capability, which is used to receive control commands and continuously adjust the output current of the branch. The voltage regulator module includes an energy storage unit and a bidirectional DC-DC converter connected to the energy storage unit; The switching control module is configured to: acquire the electrical parameters of each input branch in the multi-input module and the real-time load status of the power supply bus of the railway signaling equipment at a preset sampling time interval; obtain the dynamic drop threshold, voltage effective value drop rate, and voltage change rate based on the electrical parameters and real-time load status of each input branch; perform failure prediction based on the voltage effective value drop rate, voltage change rate, and dynamic drop threshold; and output a switching command and transient support enable signal when the voltage effective value drop rate and voltage change rate meet the preset trigger conditions. The fast switching module is configured to disconnect the mains input branch and connect the backup power branch according to the switching command; The voltage stabilizing module is configured to output compensated power to the power supply bus of the railway signaling equipment according to the transient support enable signal; The switching control module is also configured to: detect the voltage recovery status of the power supply bus of the railway signaling equipment, generate steady-state power distribution parameters to control the multi-input module to perform power distribution, the steady-state power distribution parameters specifically being the current reference commands for controlling the power converters in each input branch, and summarizing the system operation data and outputting it to an external maintenance terminal.

2. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs as described in claim 1, characterized in that, The electrical parameters and real-time load status of each input branch are as follows: The electrical parameters of each input branch include at least the electrical parameters of the mains input branch, which include: the instantaneous voltage of the mains input branch, the output current of the mains input branch, and the effective value of the rated voltage of the mains input branch. The real-time load status includes: the real-time voltage of the railway signaling equipment power supply bus, the real-time current of the railway signaling equipment power supply bus, and the design maximum rated power of the railway signaling equipment power supply bus.

3. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 2, characterized in that, The specific configuration for failure prediction in the switching control module is as follows: The real-time load power is obtained based on the real-time voltage and real-time current of the power supply bus of the railway signaling equipment, and the dynamic sag threshold is determined in combination with the design maximum rated power, the preset basic sag threshold and the load sensitivity coefficient; the voltage effective value sag rate is obtained based on the instantaneous voltage and rated voltage effective value of the mains input branch, and the voltage change rate is obtained based on the change of instantaneous voltage over time; it is determined whether the voltage effective value sag rate is greater than the dynamic sag threshold and the duration exceeds a preset time window, and whether the voltage change rate is greater than a preset change rate limit threshold; If the effective voltage drop rate is greater than the dynamic drop threshold and the duration exceeds a preset time window, or if the voltage change rate is greater than a preset change rate limit threshold, then it is determined that the mains input branch is about to fail, the preset triggering condition is met, and the switching command and the transient support enable signal are output. Otherwise, if the mains input branch is deemed to be normal, the switching command will not be output.

4. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 1, characterized in that, The switching control module has a built-in operation control strategy, which includes: multi-source allocation strategy, transient support strategy, energy recharge strategy and thermal management strategy.

5. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 4, characterized in that, The backup power supply branch includes a traction feedback input branch and a distributed renewable energy input branch; the multi-source allocation strategy is as follows: When the power supply bus of the railway signaling equipment is in a steady-state power supply stage, the available traction feedback power of the traction feedback input branch and the available distributed new energy power of the distributed new energy input branch are obtained first. The specific methods for obtaining the available traction feedback power and the available distributed new energy power are: receiving the available power data transmitted in real time from the corresponding external power generation system through the communication bus inside the system, or obtaining it based on the open circuit voltage and maximum rated output current of the corresponding input branch side. When the sum of the available power of traction feedback and the available power of distributed new energy is greater than or equal to the real-time load power, the fast switching module is controlled to disconnect the mains input branch according to the preset rated capacity ratio, and the backup power branch supplies power independently. When the sum of the available power of traction feedback and the available power of distributed new energy is less than the real-time load power, the mains input branch is connected to make up the difference in power.

6. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 4, characterized in that, The transient support strategy is as follows: Upon receiving the switching command, the bidirectional DC-DC converter in the voltage regulator module switches from standby mode to boost discharge mode; When the fast switching module is in the dead zone between the disconnection of the mains input branch and the closure of the backup power branch, it limits the voltage fluctuation of the railway signal equipment power supply bus to a preset voltage fluctuation range, and outputs a preset peak power to the railway signal equipment power supply bus through dual closed-loop control of voltage outer loop and current inner loop to compensate for the bus voltage gap.

7. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 4, characterized in that, The energy recharge strategy is as follows: When the backup power supply branch is fully connected and the voltage of the railway signal equipment power supply bus is greater than or equal to the preset rated voltage of the power supply bus, the bidirectional DC converter in the voltage regulator module exits the boost discharge mode and enters the buck charging mode. The remaining power of the backup power branch is used to charge the energy storage unit in the voltage regulator module; charging stops when the terminal voltage of the energy storage unit returns to the rated energy storage voltage.

8. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 4, characterized in that, The voltage regulator module also includes a semiconductor temperature control component attached to the surface of the energy storage unit, and the thermal management strategy is as follows: Set the preset antifreeze temperature threshold to be lower than the preset heat dissipation temperature threshold; When the surface temperature of the energy storage unit is lower than the antifreeze temperature threshold, the heating mode of the semiconductor temperature control component is triggered; When the surface temperature of the energy storage unit is higher than the heat dissipation temperature threshold, the cooling mode of the semiconductor temperature control component is triggered. When the surface temperature of the energy storage unit is greater than or equal to the antifreeze temperature threshold and less than or equal to the heat dissipation temperature threshold, the control semiconductor temperature control component is in standby mode.

9. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 1, characterized in that, The backup power supply branch includes a distributed new energy input branch for connecting to new energy sources, and a traction feedback input branch for connecting to train feedback energy. The fast switching module includes multiple sets of solid-state switches connected in series between the multi-input module and the power supply bus of the railway signaling equipment, used to realize the conduction and isolation of each input branch; The energy storage unit is connected in parallel to the power supply bus of the railway signaling equipment, and the bidirectional DC-DC converter connects the energy storage unit and the power supply bus. The switching control module includes a high-speed digital signal processor for real-time acquisition of electrical parameters of each input branch.

10. The seamless switching and wide-range voltage regulation system for railway signal power supplies suitable for mixed inputs according to claim 9, characterized in that, It also includes a health early warning module; The health warning module is used to continuously record the turn-on delay time of the solid-state switch and the voltage drop slope of the energy storage unit during each switching process. When the solid-state switch turn-on delay is detected to increase three times consecutively and exceed the preset delay threshold, or when the voltage rise rate of the energy storage unit under the preset constant current charging condition is lower than the preset proportion of the preset calibration value, an early warning signal is generated and reported to the external maintenance terminal through the communication interface to prompt equipment maintenance; otherwise, the system is kept in normal operating status.

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