Station building power supply apparatus, power conversion control system, power conversion control method, and power conversion control program

Abstract

A station building power supply apparatus (10) comprises a power converter (41) for converting DC power from a DC overhead wire (2) into AC power, and outputs power to load equipment (9) in a station building (7) that receives power supplied from a high-voltage power distribution grid (90). The station building power supply apparatus (10) comprises: a ripple component detection unit (53) for detecting a ripple component included in an overhead wire voltage; a regenerative operation determination unit (51) for determining, on the basis of the ripple component, whether or not an electric vehicle (1) that travels by receiving the overhead wire voltage is performing a regenerative operation; a storage unit (62) for storing and managing the number of past operations of the power converter (41); and a control unit (61) for controlling the operation start time of the power converter (41) on the basis of the determination result from the regenerative operation determination unit (51) and the number of operations.

Description

Station building power supply unit, power conversion control system, power conversion control method, and power conversion control program

[0001] This disclosure relates to a station building power supply device, a power conversion control system, a power conversion control method, and a power conversion control program that utilize regenerative power generated by electric trains in overhead lines.

[0002] Conventionally, station building power supply systems recover regenerative power generated by electric trains on the DC side of the overhead line, convert the DC power to AC power, and supply AC power to the station building equipment on the AC side of the station building's AC system. When regenerative power is generated, such as when an electric train decelerates, the voltage value of the overhead line rises. The station building power supply system compares the overhead line voltage value with a regenerative determination voltage value used to determine whether or not an electric train connected to the overhead line is performing regenerative operation, and performs regenerative power recovery operation if the overhead line voltage value is higher. In this type of station building power supply system, Patent Document 1 below discloses a technology for efficiently recovering regenerative power from electric trains by devising a method for calculating the regenerative determination voltage value.

[0003] International Publication No. 2016 / 132508

[0004] However, conventional station building power supply systems, including those described in Patent Document 1, do not take into consideration the number of power conversion operations performed when recovering regenerative power. An increase in the number of power conversion operations leads to a problem in that the lifespan of the power converters in the station building power supply system decreases. On the other hand, simply limiting the number of operations to address the problem of reduced equipment lifespan leads to a decrease in the amount of regenerative power recovered, resulting in an inefficient recovery of regenerative power.

[0005] This disclosure is made in view of the above, and aims to provide a station building power supply device that can efficiently recover regenerative power from electric trains while suppressing a decrease in equipment lifespan.

[0006] To solve the aforementioned problems and achieve the objectives, the station building power supply device according to this disclosure comprises a regenerative operation determination unit and a control unit. The regenerative operation determination unit determines whether or not an electric train running on power received from an overhead line is performing regenerative operation. The control unit controls the start time of the operation of the power converter based on the determination result of the regenerative operation determination unit and the number of operations of the power converter that converts the DC power of the overhead line to AC power.

[0007] The station building power supply system described in this disclosure has the effect of efficiently recovering regenerative power from electric trains while suppressing the reduction in equipment lifespan.

[0008] Figure 1 shows an example configuration of a station building power supply system including a station building power supply device according to Embodiment 1. Figure 2 shows an example configuration of a station building power supply system including a station building power supply device according to a modified example of Embodiment 1. Figure 3 shows the first half of a flowchart used to explain a control method using the station building power supply device according to Embodiment 1. Figure 4 shows the second half of a flowchart used to explain a control method using the station building power supply device according to Embodiment 1. Figure 4 shows an explanation of the process of step ST15 in the flowchart. Figure 1 shows an explanation of the effects of the station building power supply device according to Embodiment 1. Figure 4 shows a block diagram showing an example of a hardware configuration that realizes the functions of the station building power supply device according to Embodiment 1. Figure 5 shows an example configuration of a station building power supply system including a station building power supply device according to Embodiment 2. Figure 6 shows an example configuration of a station building power supply system including a station building power supply device according to Embodiment 3. Figure 7 shows an example configuration of an external device shown in Figure 9. Figure 8 shows an example configuration of a station building power supply system including a station building power supply device according to Embodiment 4.

[0009] The station building power supply device, power conversion control system, power conversion control method, and power conversion control program according to the embodiments of this disclosure will be described in detail below with reference to the attached drawings.

[0010] Embodiment 1. Figure 1 is a diagram showing an example configuration of a station building power supply system including a station building power supply unit 10 according to Embodiment 1. Figure 1 shows an electric train 1, a station building power supply unit 10, and a station building 7 as components of the station building power supply system. The station building power supply unit 10 comprises a power converter 4 and a monitoring and control panel 5. The station building 7 comprises a transformer 8 and load equipment 9. The transformer 8 converts the AC (Alternating Current) 6600V system AC voltage applied from the high-voltage distribution system 90 to a low-voltage AC 210V system AC voltage. The AC 210V system is an example of an AC system. The load equipment 9 operates by receiving power supplied from the AC 210V system. The load equipment 9 is a general term for various load equipment such as air conditioning equipment, lighting equipment, and elevators installed in the station building 7.

[0011] The power converter 4 converts the DC (Direct Current) 1500V system power generated by regenerative power in the DC overhead line 2 due to the deceleration operation of the electric vehicle 1 into AC 210V system power and supplies it to the load equipment 9. The DC 1500V system is an example of a DC system where the overhead line voltage is DC 1500V. To realize this function, the power converter 4 is equipped with a power converter 41 and a voltage sensor 42, and the monitoring control panel 5 controls the operation of the power converter 41 based on the output of the voltage sensor 42. The voltage sensor 42 may be located outside the power converter 4.

[0012] As described above, the station building power supply unit 10 is equipped with a power converter 41 that converts DC power supplied from the DC overhead line 2 into AC power, and is configured to output the AC power converted by the power converter 41 to the load equipment 9 of the station building 7, which receives power supplied from the AC system.

[0013] The monitoring control panel 5 comprises a power control unit 6, a regenerative operation determination unit 51, and a display unit 52. The power control unit 6 comprises a control unit 61 and a storage unit 62. The regenerative operation determination unit 51 comprises a ripple component detection unit 53.

[0014] The voltage sensor 42 detects the overhead line voltage generated between the DC overhead line 2 and the rail 3. The ripple component detection unit 53 detects the ripple component contained in the overhead line voltage detected by the voltage sensor 42 and outputs the information of the detected ripple component and the overhead line voltage value at the time the ripple component was detected to the power control unit 6.

[0015] The regenerative operation determination unit 51 determines whether the electric vehicle 1, which is running on power from the overhead line voltage, is performing regenerative operation based on the ripple component contained in the overhead line voltage, or more specifically, the content of the ripple component. If the electric vehicle 1 is performing regenerative operation, the regenerative operation determination unit 51 generates a regenerative operation signal indicating that the electric vehicle 1 is performing regenerative operation and outputs it to the control unit 61. The output status of the regenerative operation signal generated by the regenerative operation determination unit 51 can be displayed on the display unit 52. Note that the method of using the content of the ripple component to determine whether the electric vehicle 1 is performing regenerative operation is publicly known, and a detailed explanation is omitted here. A specific determination procedure is disclosed, for example, in the above-mentioned Patent Document 1, so please refer to the contents of that publication.

[0016] Furthermore, the determination of whether or not electric vehicle 1 is performing regenerative operation is not limited to a method using the ripple component content, but can be made using any other method that allows for the determination of whether or not electric vehicle 1 is performing regenerative operation. Other methods for determining whether or not electric vehicle 1 is performing regenerative operation include, for example, a method in which regenerative operation is determined when a predetermined regenerative determination voltage value, which is the voltage value at which electric vehicle 1 begins regeneration, exceeds the overhead line voltage.

[0017] The memory unit 62 stores and manages information on the past number of operations of the power converter 41. When a regenerative operation signal is received from the regenerative operation determination unit 51, the control unit 61 operates the power converter 41 to control the load equipment 9 to consume the regenerative power generated in the DC overhead line 2. At this time, the control unit 61 controls the start time of operation of the power converter 41 based on the operation count information held by the memory unit 62, or more specifically, the cumulative value of the operation count. The start time of operation is set in advance and stored in the memory unit 62. Details regarding the control of the start time of operation will be described later.

[0018] The configuration of the station building power supply unit 10 is not limited to the configuration shown in Figure 1. For example, it can be configured in a modified form as shown in Figure 2. Figure 2 is a diagram showing an example configuration of a station building power supply system including the station building power supply unit 10 according to a modified example of Embodiment 1. As shown in Figure 2, the functions of the power control unit 6 may be provided by the power converter 4. In addition, similar to the power control unit 6, some or all of the functions of the monitoring and operation panel 5 may be provided by the power converter 4.

[0019] Next, the control method using the station building power supply device 10 according to Embodiment 1 will be described with reference to Figures 3 to 5. Figure 3 is a diagram showing the first half of the flowchart used to explain the control method using the station building power supply device 10 according to Embodiment 1, and Figure 4 is a diagram showing the second half of the flowchart used to explain the control method using the station building power supply device 10 according to Embodiment 1. Figure 5 is a diagram used to explain the process of step ST15 in the flowchart of Figure 4.

[0020] First, the voltage sensor 42 detects the overhead line voltage of the DC overhead line 2 (step ST11). The regenerative operation determination unit 51 determines whether or not regenerative operation is being performed, that is, whether or not the electric vehicle 1 is performing regenerative operation, based on the ripple component content (step ST12). As mentioned above, the ripple component content in the overhead line voltage is calculated by the ripple component detection unit 53. If the electric vehicle 1 is not performing regenerative operation (step ST13, No), the process returns to step ST11, and steps ST11 to ST13 are repeated. On the other hand, if the electric vehicle 1 is performing regenerative operation (step ST13, Yes), the regenerative operation determination unit 51 transmits a regenerative operation signal to the control unit 61 (step ST14).

[0021] The control unit 61, triggered by the reception of a regenerative operation signal, predicts the final number of operations (step ST15). The final predicted number of operations is the predicted number of operations at the end of a predetermined period. The control unit 61 calculates the final predicted number of operations based on the cumulative number of operations. The calculation process for the final predicted number of operations will be further explained with reference to Figure 5.

[0022] FIG. 5 shows the change in the integrated operation count that changes over time. The horizontal axis in FIG. 5 represents time, and the thick solid line curve is the actual data of the integrated operation count. The integrated operation count is an example of the stored information held in the storage unit 62. The integrated operation count is the integrated value of the operation count of the power converter 41, and is obtained by integrating the past operation count of the power converter 41. The operation count of the power converter 41 is the number of times the power converter 41 has performed the regenerative power recovery operation. The recovery operation is an operation of causing the load device 9 to consume the regenerative power generated in the DC overhead line 2. As described above, the power converter 41 performs the regenerative power recovery operation according to the instruction of the control unit 61.

[0023] Inside the power converter 41, there is a controller (not shown). When the control unit 61 causes the power converter 41 to perform the regenerative power recovery operation, the control unit 61 outputs a recovery operation instruction signal to the controller of the power converter 41. When the controller of the power converter 41 receives the recovery operation instruction signal, it operates the power converter 41 and performs control to cause the load device 9 to consume the regenerative power generated in the DC overhead line 2. Also, when the control unit 61 stops the recovery operation of the power converter 41, the control unit 61 outputs a recovery operation stop signal to the controller of the power converter 41. When the controller of the power converter 41 receives the recovery operation stop signal, it stops the operation of the power converter 41 and performs control to stop the regenerative power recovery operation. The operation count is counted as one time from when the recovery operation instruction signal is output and the power converter 41 operates until the power converter 41 stops operating by the recovery operation stop signal.

[0024] As the device life of the power converter 41, for example, 20 to 30 years is assumed. The full span of the horizontal axis in FIG. 5 is, for example, one day. In this case, the initial time point T ｉｎｉｔ on the horizontal axis is the starting time as seen for all the electric vehicles 1 when they are running on a route with a plurality of electric vehicles 1, and the final time point T ｌａｓｔ on the horizontal axis is the end time of the operation as seen for all the electric vehicles 1.

[0025] According to the actual data shown in FIG. 5, information that the integrated operation count is N times at the time point t ｉ－１ has been obtained. At the time point t ０At a certain point in the future, when the control unit 61 receives information from the regenerative operation determination unit 51 indicating that the electric vehicle 1 is performing a regenerative operation, as described above, the control unit 61 causes the power converter 41 to perform a regenerative power recovery operation. When the control unit 61 causes the power converter 41 to perform a regenerative power recovery operation, the integrated operation count increases by 1 and becomes N + 1 times. When causing the (N + 1)-th recovery operation to be performed, the control unit 61 predicts the number of operations at the final point T ｌａｓｔ In this article, the predicted value of the number of operations at the final point T ｌａｓｔ in a predetermined period is referred to as the "final predicted number of operations."

[0026] In FIG. 5, when the point at which the timing of determining whether to cause the (N + 1)-th recovery operation of the integrated operation count is t i , the control unit 61 predicts the final predicted number of operations as N ｉ－１ from the slope of the straight line connecting the point t s ｉ and the point t ｉ . Also, when the point at which the timing of determining whether to cause the (N + 1)-th recovery operation of the integrated operation count is t ｉ ', the control unit 61 predicts the final predicted number of operations as N ｉ－１ ' from the slope of the straight line connecting the point t ｉ ' and the point t ｉ '. Also, when the point at which the timing of determining whether to cause the (N + 1)-th recovery operation of the integrated operation count is t ｉ ", the control unit 61 predicts the final predicted number of operations as N ｉ－１ " from the slope of the straight line connecting the point t ｉ " and the point t ｉ ". The information on the predicted final predicted number of operations is stored in the storage unit 62

[0027] Here, when the final predicted number of operations predicted at the point t is represented by C(t), C(t) can be expressed by the following equation (1).

[0028] C(t) = N + (T ｌａｓｔ - t) / (t - t ｉ－１ )... (1)

[0029] The above equation (1) is a calculation formula for determining the final predicted number of operations using linear approximation, but it is not limited to linear approximation, and the final predicted number of operations may also be determined using a calculation formula that applies a function other than a straight line. These calculation formulas can be stored in the memory unit 62. If the memory unit 62 holds multiple calculation formulas, the calculation formula may be switched depending on the time period in which regeneration occurs. In this way, a balance can be struck between the frequency of regeneration, the calculation time of the final predicted number of operations, and the calculation accuracy of the final predicted number of operations, and the power converter 41 can be instructed to perform recovery operations at an appropriate timing.

[0030] Returning to the explanation of the flowchart in Figure 4, the control unit 61 determines whether the final predicted number of operations predicted in step ST15 is within the range of the assumed number of operations (step ST16). In Figure 5, the lower threshold is set to N. １ Let the upper threshold be N ２ Examples of the expected range of operations are shown in hatching. If the final predicted number of operations is within the expected range (step ST16, Yes), the control unit 61 does not change the operation start time of the power converter 41, and when the operation start time is reached, it instructs the power converter 41 to perform a recovery operation (steps ST17, ST21). In Figure 5, the final predicted number of operations is N ｉ If this is predicted, the process in step ST17 is performed. Needless to say, the process in step ST21 is based on the premise that the regenerative operation signal is continuously output from the regenerative operation determination unit 51. Therefore, if the regenerative operation signal from the regenerative operation determination unit 51 is interrupted, the instruction to perform a recovery operation on the power converter 41 is not performed.

[0031] Furthermore, if the final predicted number of operations is not within the range of the assumed number of operations (step ST16, No), the control unit 61 determines that the final predicted number of operations is within the upper threshold N of the assumed number of operations. ２ It is determined whether or not it exceeds the threshold (step ST18). The final predicted number of operations is the upper threshold N of the assumed number of operations. ２If the number of operations exceeds the limit (step ST18, Yes), the control unit 61 delays the start time of the power converter 41 by one step, and when the changed start time is reached, it instructs the power converter 41 to perform a recovery operation (steps ST19, ST21). In Figure 5, the final predicted number of operations is N. ｉ If this is predicted, the process in step ST19 is performed. Note that, as with the transition from step ST17 to step ST21, if the regenerative operation signal from the regenerative operation determination unit 51 is interrupted, the instruction to perform a recovery operation to the power converter 41 is not issued.

[0032] Furthermore, the final predicted number of operations is the upper threshold N of the expected number of operations. ２ If it does not exceed (Step ST18, No), the final predicted number of operations is determined from the results of Steps ST16 and ST18 to be the lower threshold N. １ It can be seen that it is below this value. Therefore, the control unit 61 advances the start time of the power converter 41 by one step, and when the changed start time is reached, it instructs the power converter 41 to perform a recovery operation (steps ST20, ST21). In Figure 5, the final predicted number of operations is N. ｉ If this is predicted, the process in step ST20 is performed. Note that, as with the transition to steps ST17 to ST21, if the regenerative operation signal from the regenerative operation determination unit 51 is interrupted, the instruction to perform a recovery operation to the power converter 41 is not issued.

[0033] In the processes of steps ST19 and ST20 described above, the time interval for delaying or advancing the start time of operation is arbitrary. It is desirable that the station building power supply unit 10 be configured so that the user or manager of the station building power supply unit 10 can arbitrarily set this time interval.

[0034] Here, we will provide some supplementary information regarding Figure 5. While the full span of the horizontal axis in Figure 5 is assumed to be one day, this example is not limiting. The full span of the horizontal axis in Figure 5 may also be a period of one month or one year. Furthermore, the memory unit 62 may store information on the cumulative number of operations for these multiple patterns. If the full span uses a curve representing the cumulative number of operations over one month, the final predicted number of operations for the one-month period may be predicted, and the operation start time may be changed according to the flow in Figure 4. This process can be implemented in conjunction with the flow in Figure 4. Similarly, if the full span uses a curve representing the cumulative number of operations over one year, the final predicted number of operations for the year may be predicted, and the operation start time may be changed according to the flow in Figure 4. This process can be implemented in conjunction with the flow in Figure 4. Note that the lower threshold N is... １ and upper threshold N ２ This value does not need to be fixed and may be changed according to the cumulative number of operations, the amount of change in the cumulative number of operations, the operating time period, the schedule density, the day of the week (weekday or holiday), etc. The cumulative number of operations may be not only the current cumulative number of operations, but also the cumulative number of operations from the previous day, the previous month, or the previous year.

[0035] Next, the effects of using the station building power supply device 10 according to Embodiment 1 will be explained. Figure 6 is a diagram illustrating the effects of the station building power supply device 10 according to Embodiment 1. Figure 6 shows the change in output power when the power converter 41 performs regenerative power recovery operation using conventional technology. The height of the bar graph represents the magnitude of the output power, and it is assumed that a constant power (for example, 200 kW) is output from the power converter 41 to the load equipment 9 during the regenerative power recovery operation. The width of the bar graph represents the output time.

[0036] In Figure 6, focusing on the bar graphs for the 1st to 4th cycles, the sum of the output times for the 1st to 3rd cycles is approximately the same as the output time for the 4th cycle. Therefore, it can be said that the sum of the regenerative power recovered during the 1st to 3rd cycles is roughly equal to the regenerative power recovered during the 4th cycle. On the other hand, when considering the equipment lifespan of the power converter 41, the fewer the number of operations of the power converter 41, the longer the equipment lifespan. The semiconductor switching elements in the power converter 41 are subjected to temperature change stress by repeatedly switching on and off, but the thermal time constant of temperature change is shorter than the operation time, so the number of operations of the power converter 41 is the dominant factor influencing the equipment lifespan of the power converter 41. Therefore, in order to increase regenerative efficiency while suppressing the decrease in equipment lifespan, it is effective to suppress operations with short output times. By using the control method according to the above-described embodiment 1, it is possible to suppress the 1st and 2nd operations with short output times, as shown in Figure 6, so that it is possible to efficiently recover the regenerative power of the electric vehicle 1 while suppressing the decrease in equipment lifespan.

[0037] At the end of Embodiment 1, the hardware configuration for realizing the functions of the station building power supply device 10 described above will be explained with reference to Figure 7. Figure 7 is a block diagram showing an example of a hardware configuration for realizing the functions of the station building power supply device 10 according to Embodiment 1.

[0038] In order to implement some or all of the functions of the station building power supply device 10 according to Embodiment 1, the configuration may include a processing circuit 70 that performs calculation and control processing, an input / output interface 73 that performs input and output of signals and data, and a system bus 74 that connects the processing circuit 70 and the input / output interface 73, as shown in Figure 7. Furthermore, the processing circuit 70 may be configured as a computer system including a processor 71 and a memory 72 that stores programs read by the processor 71 and data input and output by the input / output interface 73.

[0039] The processor 71 is an example of a computing means. The processor 71 may be a computing means referred to as a microprocessor, microcomputer, CPU (Central Processing Unit), or DSP (Digital Signal Processor). The memory 72 may be an example of a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), or EEPROM (Registered Trademark) (Electrically EPROM).

[0040] Memory 72 stores a program that performs the functions of the station building power supply unit 10 described above. The processor 71 receives necessary information via the input / output interface 73, executes the program stored in memory 72, and references the data stored in memory 72, thereby performing the above-described processing. The calculation results by the processor 71 can be stored in memory 72. The program executed by the processor 71 may be provided in a state stored on a storage medium, or it may be provided via a communication channel such as the internet.

[0041] Alternatively, instead of a configuration comprising a processor 71 and memory 72, the processing circuit 70 may be composed of a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a circuit combining these. Information input to and output from the processing circuit 70 can be exchanged via the input / output interface 73. Furthermore, the functions of the station building power supply unit 10 described above may be realized in a configuration that includes a processor 71 and memory 72, while also comprising a processing circuit 70 composed of a single circuit, a composite circuit, an ASIC, or an FPGA.

[0042] As described above, the station building power supply device 10 according to Embodiment 1 comprises a regenerative operation determination unit 51 and a control unit 61. The regenerative operation determination unit 51 determines whether or not an electric train running on power received from an overhead line is performing regenerative operation. The control unit 61 controls the start time of operation of the power converter 41 based on the determination result of the regenerative operation determination unit 51 and the number of operations of the power converter that converts the DC power of the overhead line to AC power. According to the station building power supply device 10 according to Embodiment 1, the recovery operation of regenerative power with a short output time in the power converter 41 can be suppressed, so it is possible to efficiently recover the regenerative power of the electric train 1 while suppressing a decrease in the equipment life of the power converter 41.

[0043] Furthermore, the power conversion control method according to Embodiment 1 can include the steps of: detecting a ripple component included in the overhead line voltage applied from the overhead line; determining whether or not the electric vehicle, which is running on power received from the overhead line voltage, is performing regenerative operation based on the ripple component; and controlling the start time of the operation of the power converter based on the number of operations of the power converter that converts DC power from the overhead line to AC power. By using a power conversion control method that includes each of these steps, the recovery operation of regenerative power with a short output time in the power converter 41 can be suppressed, making it possible to efficiently recover regenerative power from the electric vehicle 1 while suppressing a decrease in the equipment life of the power converter 41.

[0044] The memory unit 62 may store past regenerative power amounts per hour, per day, per month, and per season. The memory unit 62 may also store a lower threshold N that determines the range of expected operation cycles. １ Upper threshold N ２ , the last point in the past T ｌａｓｔThe calculated value of the final predicted number of operations may be stored. It is desirable that the number of operations of the power converter 41 be stored separately for each item, such as the day of the week (weekday or holiday), operating time, schedule density, weather, and season, as these factors may vary. If the information stored in the storage unit 62 is stored with such considerations, the range of assumed operations will be appropriately set according to the operating conditions of the electric vehicle 1, thereby enabling more efficient recovery of regenerative power from the electric vehicle 1.

[0045] Embodiment 2. Embodiment 2 describes a control method in which the operation start time in the control method of Embodiment 1 is clarified using the concept of waiting time. The control method of Embodiment 2 can use the station building power supply device 10 according to Embodiment 1. The station building power supply device 10 may be configured in either of the configurations shown in Figure 1 and Figure 2.

[0046] Figure 8 is a diagram illustrating a control method using the station building power supply device 10 according to Embodiment 2. Figure 8 shows the change in output power when the power converter 41 performs regenerative power recovery operation using conventional technology. The meaning of the height and width of the bar graph is the same as in Figure 6. Note that the full span of the horizontal axis is different from that in Figure 6. In Figure 8, the full span of the horizontal axis is set to 1 hour.

[0047] Next, the waiting time will be explained. The waiting time is the time during which the instruction to perform a recovery operation on the power converter 41 is withheld. In Embodiment 1, the recovery operation was instructed after the start time of operation had been reached, but in Embodiment 2, the waiting time is a factor that determines this start time of operation. In actual control, the waiting time is from the moment the control unit 61 receives the regenerative operation signal from the regenerative operation determination unit 51 until the moment the control unit 61 actually outputs a control signal to operate the power converter 41. The waiting time is set in advance and stored in the storage unit 62.

[0048] In Figure 8, the standby time width, which is the length of the standby time, is indicated by a double-headed arrow. In the output power patterns shown in Figure 8, if the number of times the power converter 41 operates per hour is limited to, for example, 5 times, in the conventional technology without setting a standby time, it operates in output power patterns #1 to #5, and in output power patterns #6 to #8, the recovery operation of the power converter 41 is suppressed due to the limit on the number of operations. In contrast, in Embodiment 2 with a standby time set, it operates in output power patterns #3 to #5, #7 and #8, and in output power patterns #1, #2 and #6, the recovery operation of the power converter 41 is suppressed because the output time, indicated by the width of the bar graph, is shorter than the standby time. Since the sum of the areas of the bar graphs at the operating points corresponds to the regenerative energy that can be recovered, it can be seen that Embodiment 2 with a standby time set has higher regenerative efficiency than the conventional technology without a standby time set.

[0049] Furthermore, the station building power supply unit 10 according to Embodiment 2 may predict the final predicted number of operations and change the standby time based on the predicted final predicted number of operations, similar to Embodiment 1. The process of changing the standby time can be carried out in accordance with the flowchart in Figure 4. The specific processing details are as follows.

[0050] The control unit 61 determines whether the predicted final number of operations is within the range of the assumed number of operations. If the predicted final number of operations is within the range of the assumed number of operations, it instructs the power converter 41 to perform a recovery operation after the waiting time has elapsed without changing the waiting time. Furthermore, the control unit 61 determines whether the predicted final number of operations is within the upper limit threshold N ２ If it exceeds the limit, the waiting time is increased, and after the changed waiting time has elapsed, the power converter 41 is instructed to perform a recovery operation. In addition, the control unit 61 determines when the predicted final number of operations is below the lower limit threshold N. １ If the value falls below a certain level, the waiting time is increased, and after the changed waiting time has elapsed, the power converter 41 is instructed to perform a recovery operation.

[0051] As described above, according to the station building power supply device 10 of Embodiment 2, the control unit 61 determines the start time of operation using a waiting time during which it suspends the instruction to the power converter 41 to perform a recovery operation. By using the station building power supply device 10 of Embodiment 2, the recovery operation of regenerative power with a short output time in the power converter 41 can be suppressed, and the same effects as in Embodiment 1 can be obtained.

[0052] The memory unit 62 may store past regenerative power amounts per hour, per day, per month, and per season. The memory unit 62 may also store a lower threshold N that determines the range of expected operation cycles. １ Upper threshold N ２ , the last point in the past T ｌａｓｔ The calculated value of the final predicted number of operations may be stored. It is desirable that the number of operations of the power converter 41 be stored separately for each item, such as the day of the week (weekday or holiday), operating time, schedule density, weather, and season, as these factors may vary. If the information stored in the storage unit 62 is stored with such considerations, the range of assumed operations will be appropriately set according to the operating conditions of the electric vehicle 1, thereby enabling more efficient recovery of regenerative power from the electric vehicle 1.

[0053] The initial value of the waiting time does not need to be a fixed value; it may be changed according to the cumulative number of operations, the amount of change in the cumulative number of operations, the operating time period, the schedule density, the day of the week (weekday or holiday), etc. The cumulative number of operations may be not only the current cumulative number of operations, but also the cumulative number of operations for the previous day, the previous month, or the previous year. Furthermore, the value of the waiting time may be set discretely. In this case, the waiting time can be changed by changing the steps.

[0054] Embodiment 3. Embodiment 3 describes a station building power supply system with a different configuration from Figures 1 and 2. Figure 9 is a diagram showing an example configuration of a station building power supply system including a station building power supply device 10 according to Embodiment 3. Compared with the configuration in Figure 1, in Figure 9, an external device 80 is provided outside the station building power supply device 10, which is configured to communicate with the power control unit 6. Although Figure 9 is an example of application to the configuration in Figure 1 in which the power control unit 6 is provided on the monitoring and operation panel 5, it can also be applied to the configuration in Figure 2 in which the power control unit 6 is provided on the power converter 4. In Embodiment 3, the station building power supply device 10 and the external device 80 constitute a power conversion control system.

[0055] Figure 10 is a block diagram showing an example configuration of the external device 80 shown in Figure 9. The external device 80 is implemented by a computer system comprising a processor 81, memory 82, communication device 83, and storage device 84. The processor 81, memory 82, communication device 83, and storage device 84 are connected by a system bus 85.

[0056] The processor 81 is a computing means such as a CPU, MCU (Micro Control Unit), GPU (Graphics Processing Unit), or DSP. The memory 82 is a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM (registered trademark). The communication device 83 is a device that provides communication functions for exchanging necessary information with the power control unit 6. The storage device 84 is a device for holding various information necessary for the recovery control of regenerative power, and is composed of storage means such as flash memory, EPROM, EEPROM (registered trademark), magnetic disk, flexible disk, optical disk, compact disk, minidisc, or DVD (Digital Versatile Disc), or a combination of some of these storage means.

[0057] The memory 82 stores the program necessary for the operation of the processor 81, and the processor 81 reads and executes the program stored in the memory 82. The calculation results of the processor 81 can be stored in the memory 82 or the storage device 84. The program executed by the processor 81 may be provided in a state stored on a storage medium, or it may be provided via a communication channel such as the internet.

[0058] Furthermore, the processor 81 exchanges necessary information with the power control unit 6 via the communication device 83. The information received from the power control unit 6 is stored in the storage device 84.

[0059] The storage device 84 stores information such as the past number of operations of the power converter 41, as well as various operation information described in Embodiments 1 and 2. The various operation information referred to here includes the past hourly regenerative power amount, daily regenerative power amount, monthly regenerative power amount, seasonal regenerative power amount, and a lower threshold N that determines the range of the expected number of operations. １ Upper threshold N ２ , the last point in the past T ｌａｓｔ This includes the calculated value of the final predicted number of operations. Since this operation information constitutes a large amount of data, a configuration in which the storage device 84 of the external device 80 holds this data is more useful than one in which the storage unit 62 of the power control unit 6 holds it, as in Embodiments 1 and 2, from the standpoint of being able to configure the power control unit 6 in a simpler and lower-cost manner.

[0060] As described above, the power conversion control system according to Embodiment 3 comprises an external device 80 having a storage device 84 and a station building power supply device 10, the station building power supply device 10 comprising a ripple component detection unit 53, a regenerative operation determination unit 51 and a control unit 61. The storage device 84 stores operation information including the past number of operations of the power converter 41. The ripple component detection unit 53 detects the ripple component included in the overhead line voltage applied from the overhead line, and the regenerative operation determination unit 51 determines whether or not the electric train 1, which is running powered by the overhead line voltage, is performing a regenerative operation based on the ripple component. The control unit 61 controls the start time or standby time of the power converter 41 based on the determination result of the regenerative operation determination unit 51 and the operation information obtained from the external device 80. According to the power conversion control system according to Embodiment 3, since the recovery operation of regenerative power with a short output time in the power converter 41 can be suppressed, it is possible to efficiently recover the regenerative power of the electric train 1 while suppressing a decrease in the equipment life of the power converter 41.

[0061] The storage device 84 of the external device 80 can store the regenerative power amount per hour, per day, per month, and per season in the past. The storage device 84 also has a lower threshold N that determines the range of expected operation cycles. １ Upper threshold N ２ , the last point in the past T ｌａｓｔ The calculated value of the final predicted number of operations can be stored. It is desirable that the number of operations of the power converter 41 be stored separately for each item, such as the day of the week (weekday or holiday), operating time, schedule density, weather, and season, as this is thought to vary depending on these factors. If the information stored in the memory device 84 is stored with such considerations, the range of assumed operations will be appropriately set according to the operating conditions of the electric vehicle 1, thereby enabling more efficient recovery of regenerative power from the electric vehicle 1.

[0062] Embodiment 4. Embodiment 4 describes a station building power supply system with a different configuration from those in Figures 1, 2, and 9. Figure 11 is a diagram showing an example configuration of a station building power supply system including a station building power supply device 10 according to Embodiment 4. Compared to the configuration in Figure 9, in Figure 11, there is no power control unit 6 located inside the station building power supply device 10, and an external device 80 configured to communicate with a regenerative operation determination unit 51 is provided outside the station building power supply device 10. Furthermore, the external device 80 in Embodiment 4 has the functions of the power control unit 6. Note that the external device 80 shown in Figure 11 may be configured in the cloud or on-premise. In Embodiment 4, the station building power supply device 10 and the external device 80 constitute a power conversion control system. The functions of each component are the same as in the other embodiments.

[0063] The external device 80 is implemented by a computer system comprising a processor 81, memory 82, communication device 83, and storage device 84, similar to the configuration example shown in Figure 10. In Embodiment 4, the external device 80 includes the functions of the power control unit 6. That is, the external device 80 includes the functions of the control unit 61 and the storage unit 62. The power conversion system of Embodiment 4 may also be configured to include at least one of the control unit 61 and the storage unit 62 outside the external device 80. Furthermore, when the control unit 61 and the storage unit 62 are provided outside the external device 80, the devices having the functions of the control unit 61 and the storage unit 62 are communicated to the regenerative operation determination unit 51 and the power converter 41, respectively.

[0064] Figure 11 of Embodiment 4 shows an example configuration where the external device 80 includes a control unit 61 and a storage unit 62. In this case, the processor 81 of the external device 80 corresponds to the control unit 61, and the storage device 84 of the external device 80 functions as the storage unit 62.

[0065] The power conversion control system according to Embodiment 4 comprises an external device 80 and a station building power supply device 10. Although not shown in Figure 11, the external device 80 comprises a control unit 61 and a storage unit 62. The monitoring control panel 5 of the station building power supply device 10 comprises a regenerative operation determination unit 51 and a display unit 52. The storage unit 62 stores operation information, including the number of past operations of the power converter 41. The ripple component detection unit 53 of the regenerative operation determination unit 51 detects the ripple component included in the overhead line voltage applied from the overhead line. Based on the ripple component, the regenerative operation determination unit 51 determines whether or not the electric train 1, which is running on power from the overhead line voltage, is performing a regenerative operation. The control unit 61 controls the start time or standby time of the power converter 41 based on the determination result of the regenerative operation determination unit 51 and the operation information obtained from the storage unit 62 of the external device 80.

[0066] According to the power conversion control system of Embodiment 4, the recovery operation of regenerative power with a short output time in the power converter 41 can be suppressed, making it possible to efficiently recover regenerative power from the electric vehicle 1 while suppressing a decrease in the equipment life of the power converter 41. Furthermore, since the external device 80 is connected to the station building power supply unit 10 in a communicative manner, it is possible to control the start time or standby time of the power converter 41 for multiple station building power supply units 10 using one external device 80. As a result, it is not necessary to provide a power control unit 6 for each station building power supply unit 10, making it possible to configure a power conversion control system more simply and at a lower cost.

[0067] In Figure 11 of Embodiment 4, a configuration in which the functions of the power control unit 6 are provided on an external device 80 has been described, but the invention is not limited to this. For example, the regenerative operation determination unit 51 and the display unit 52 can also be provided outside the station building power supply unit 10. In other words, some of the functions of the monitoring operation board 5 may be realized with dedicated hardware, and some of the functions of the monitoring operation board 5 may be realized with software or firmware. In this way, the monitoring operation board 5 can realize each of the above functions by hardware, software, firmware, or a combination thereof. The power conversion control system may also be configured to include at least one of the regenerative operation determination unit 51 and the display unit 52 outside the external device 80. Furthermore, when the regenerative operation determination unit 51 and the display unit 52 are provided outside the external device 80, the devices having the functions of the regenerative operation determination unit 51 and the display unit 52 are communicated to the voltage sensor 42 and the display unit 52, respectively. The invention is not limited to the above-described examples, and by providing various configurations outside the station building power supply unit 10 and arbitrarily exchanging information, it is possible to obtain the configuration and effects of the power conversion control system according to this disclosure.

[0068] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, combine different embodiments, and omit or modify parts of the configuration without departing from the gist of the invention.

[0069] 1 Electric train, 2 DC overhead line, 3 Rail, 4 Power converter, 5 Monitoring control panel, 6 Power control unit, 7 Station building, 8 Transformer, 9 Load equipment, 10 Station building power supply unit, 41 Power converter, 42 Voltage sensor, 51 Regenerative operation determination unit, 52 Display unit, 53 Ripple component detection unit, 61 Control unit, 62 Memory unit, 70 Processing circuit, 71, 81 Processor, 72, 82 Memory, 73 Input / output interface, 74, 85 System bus, 80 External device, 83 Communication device, 84 Storage device, 90 High voltage distribution system.

Claims

1. A station building power supply device comprising: a regenerative operation determination unit that determines whether or not an electric train running on power received from an overhead line is performing regenerative operation; and a control unit that controls the start time of operation of the power converter based on the determination result of the regenerative operation determination unit and the number of operations of the power converter that converts the DC power of the overhead line to AC power.

2. The station building power supply device according to claim 1, further comprising a storage unit for storing the number of operations of the power converter.

3. The station building power supply device according to claim 1 or 2, characterized in that the regenerative operation determination unit determines whether or not the electric train is performing regenerative operation based on the ripple component included in the voltage of the overhead line.

4. The station building power supply device according to any one of claims 1 to 3, characterized in that the control unit calculates the final predicted number of operations, which is the predicted number of operations at the end of a predetermined period, based on the cumulative value of the number of operations, and if the final predicted number of operations is within the range of the upper and lower thresholds of the assumed number of operations, it instructs the power converter to perform a regenerative power recovery operation when the operation start time is reached without changing the set operation start time.

5. The station building power supply device according to claim 4, characterized in that, if the final predicted number of operations exceeds the upper threshold, the control unit delays the set operation start time, and when the modified operation start time is reached, instructs the power converter to perform a regenerative power recovery operation.

6. The station building power supply device according to claim 4 or 5, characterized in that, if the final predicted number of operations falls below the lower threshold, the control unit advances the set operation start time, and when the modified operation start time is reached, instructs the power converter to perform a regenerative power recovery operation.

7. The station building power supply device according to any one of claims 1 to 6, characterized in that the control unit determines the operation start time using a waiting time for which it suspends the instruction to the power converter to perform a regenerative power recovery operation.

8. The station building power supply device according to claim 7, characterized in that the control unit calculates the final predicted number of operations, which is a predicted value of the number of operations at the end of a predetermined period, based on the cumulative value of the number of operations, and if the final predicted number of operations is within the range of the upper and lower threshold values ​​of the assumed number of operations, it instructs the power converter to perform a regenerative power recovery operation after the waiting time has elapsed without changing the waiting time.

9. The station building power supply device according to claim 8, characterized in that, if the final predicted number of operations exceeds the upper limit threshold, the control unit increases the waiting time and instructs the power converter to perform a regenerative power recovery operation after the changed waiting time has elapsed.

10. The station building power supply device according to claim 8 or 9, characterized in that the control unit shortens the waiting time when the final predicted number of operations falls below the lower threshold, and instructs the power converter to perform a regenerative power recovery operation after the changed waiting time has elapsed.

11. A power conversion control program for causing a computer system to function as a station building power supply device according to any one of claims 1 to 10.

12. A power conversion control system comprising: an external device having a storage device that stores operation information including the number of operations of a power converter that converts DC power from an overhead line to AC power; a regenerative operation determination unit that determines whether or not an electric train running on power received from the overhead line is performing regenerative operation; and a control unit that controls the start time of operation of the power converter based on the determination result of the regenerative operation determination unit and the operation information obtained from the external device; and a station building power supply device.

13. A power conversion control system comprising: a storage unit that stores operation information including the number of operations of a power converter that converts DC power from an overhead line to AC power; a regenerative operation determination unit that determines whether or not an electric vehicle that runs on power received from the overhead line is performing regenerative operation; and a control unit that controls the start time of operation of the power converter based on the determination result of the regenerative operation determination unit and the operation information obtained from the storage unit.

14. A power conversion control method characterized by comprising: a step of determining whether or not an electric vehicle that runs on power received from an overhead line is performing regenerative operation; and a step of controlling the start time of operation of the power converter based on the determination result of the step and the number of times the power converter has operated to convert DC power from the overhead line to AC power.

15. A power conversion control program that causes a computer system to execute the power conversion control method described in claim 14.

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