JP5724665B2 - DC electric railway power storage device - Google Patents

Description

  The present invention relates to a DC electric railway, and more particularly to a power storage device used as a voltage compensator for stabilizing the voltage of a feeder line.

  In a DC electric railway, a power storage device is provided in order to suppress a voltage drop and a voltage rise of a feeding voltage generated during power running and regeneration of an electric vehicle. This power storage device has an electric double layer capacitor (hereinafter referred to as EDLC) as a power storage means, and regenerative power from an electric vehicle is charged into the EDLC via a bidirectional chopper. .

JP 2010-252617 A JP 2009-67206 A

  In the early morning and night, there are few (or no) electric vehicles traveling, so the power consumption of the electric wire is extremely low compared to the daytime, and the feeding voltage rises. Also, in the early morning and night, general power consumption other than electric vehicles and railways is reduced compared to daytime, so the transmission system voltage to the railway substation may rise more than daytime, and the feeding voltage further increases. Will be. Thus, the following problems occur when the feeding voltage increases.

  When the feeding voltage rises early in the morning and at no load at night, and the feeding voltage exceeds the charging reference voltage, the power storage device performs the regeneration absorption operation even though the regenerative vehicle does not exist. That is, the charging operation at no load at early morning and at night does not absorb regenerative power but absorbs feeder power, and becomes unnecessary operation.

  As a solution, a method of stopping the power storage device early in the morning and at night to suppress absorption of feeder power can be considered. However, there is no problem if there is no traveling electric vehicle, but if there is a traveling electric vehicle, the power storage device is stopped and the feeding voltage is rising, so it supports regeneration of the electric vehicle. Can not. That is, when the power storage device is stopped early in the morning or at night, the electric vehicle is likely to be regenerated and invalidated. Further, since the operation of the mechanical brake increases, wear of parts such as a brake disk in the mechanical brake becomes remarkable, leading to a shortened life of the parts.

  As described above, it is an object to provide a power storage device for a DC electric railway that suppresses the absorption of feeding power that is not regenerative power and suppresses regenerative invalidation of a traveling electric vehicle early in the morning and at night. It becomes.

  The present invention has been devised in view of the above-described conventional problems.One aspect of the present invention is that when the feeding voltage is equal to or higher than the charging reference voltage, the feeding voltage is charged to the power storage means via the bidirectional chopper, When the feeding voltage is equal to or lower than the discharge reference voltage, the power storage device of the DC electric railway suppresses the voltage drop and voltage rise of the feeding voltage by discharging from the power storage means to the feeder via the bidirectional chopper. When the electric vehicle is not present in the early morning and at night, and when the electric vehicle is present but no regenerative current is generated, the control unit of the bidirectional chopper is charged according to the increase of the feeding voltage. If the electric vehicle exists and regenerative current is generated from the electric vehicle early in the morning and at night, the charging reference voltage is set according to the distance between the power storage device and the electric vehicle and the regenerative current. It is characterized by that.

  In addition, the control unit of the bidirectional chopper determines the charging reference voltage in the following formula (2) when there is no electric vehicle in the early morning and at night and when there is an electric vehicle but no regenerative current is generated. You may calculate by.

  In addition, the control unit of the bidirectional chopper, when early in the morning and at night, when the electric vehicle is not present and when the electric vehicle is present but no regenerative current is generated, the charging reference voltage is set to the following (4), You may calculate by (5) Formula.

  In addition, the control unit of the bidirectional chopper may determine whether or not there is a traveling electric vehicle based on information from the traveling electric vehicle or the command center, and may set the charging not to start when the traveling electric vehicle does not exist. .

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the electric power storage apparatus of the direct current electric railway which suppresses the absorption of the feeding power which is not regenerative electric power, and suppresses the regenerative invalidation of a driving | running | working electric vehicle early in the morning and at night. .

It is the schematic which shows the direct current electric railway using the electric power storage apparatus in Embodiment 1. 1 is a configuration diagram of a power storage device in Embodiment 1. FIG. It is a flowchart which shows the operation mode setting procedure of the electric power storage apparatus in Embodiment 1. It is a cooperation conceptual diagram of a regenerative brake and a mechanical brake. It is a schematic explanatory drawing which shows an example of the communication by a distributed system. It is a schematic explanatory drawing which shows an example of the communication by a concentration system. It is a control block diagram in the regeneration absorption (at the time of charge) of the electric power storage apparatus in Embodiment 1. It is a graph which shows the charge reference voltage in normal operation [Formula (1)]. It is a graph which shows the charge reference voltage in (2) Formula. It is a graph which shows the charge reference voltage in (4), (5) type | formula. It is a control block diagram in the regeneration absorption (at the time of charge) of the conventional power storage device.

  Hereinafter, a power storage device for a DC electric railway according to Embodiments 1 and 2 of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
FIG. 1 is a schematic diagram when the power storage device 10 is used in a DC electric railway. In FIG. 1, there are a feeder 1, an electric vehicle 3 that is supplied with power from the feeder 1 and travels on a rail 2, and a power storage device 10 that is interposed between the feeder 1 and the rail 2. It is shown in the figure.

  The power storage device 10 includes a bidirectional chopper unit 11 serving as a direct current / direct current conversion unit and a power storage unit (for example, EDLC: hereinafter referred to as EDLC) 14.

  The bidirectional chopper unit 11 has semiconductor switching elements 12a and 12b (for example, IGBT) connected in series between the feeder 1 and the rail 2, and one end connected to a common connection point of the semiconductor switching elements 12a and 12b. Smoothed reactor 13. The EDLC 14 is inserted between the other end of the smoothing reactor 13 and the rail 2.

  As shown in FIG. 2, the power storage device 10 includes a filter reactor 16, a filter capacitor 17, a feeding current detector 15, a feeding voltage detector 18, an EDLC voltage detector 19, EDLC current detector 20. The filter reactor 16 and the filter capacitor 17 are directly connected between the feeder 1 and the rail 2.

  In a DC electric railway to which the power storage device 10 configured as described above is applied, when the electric vehicle 3 operates a regenerative brake as shown in FIG. (Referred to as feeding voltage) increases. In particular, when there is no load, it rises rapidly. When the feeding voltage rises, the power storage device 10 starts charging and absorbs regenerative power.

  On the other hand, when the electric vehicle 3 is powered, the electric vehicle 3 becomes a heavy load. As a result, the feeding voltage decreases, so that the power storage device 10 starts discharging, thereby compensating for the power.

FIG. 3 is a flowchart showing the procedure for setting the operation mode in the power storage device 10. First, it is determined whether or not the power storage device _feeding voltage V _dc is _{equal to} or higher than the charging reference voltage V _dcref (S1). If the charging voltage V _{dcref is equal to} or higher than the charging reference voltage V _{dcref, the process proceeds to} S2 charging operation (regenerative absorption operation). The charging operation is set as an operation mode (S3).

On the other hand, when the power storage device _feeding voltage V _dc is not _{equal to} or higher than the charging reference voltage V _{dcref, the process proceeds} to S4 to determine whether or not the power storage device _feeding voltage V _dc is equal to or lower than the discharge reference voltage. Here, when the feeding voltage is equal to or lower than the discharge reference voltage, the operation shifts to the discharge operation (power compensation operation) (S5), and this discharge operation is set as the operation mode. If it is determined that the electric voltage is not lower than the discharge reference voltage in S4, the operation proceeds to the standby operation (S6), and this standby operation is set as the operation mode (S3).

In other words, when the power storage device _feeding voltage V _dc exceeds the charging reference voltage V _dcref , the power storage device 10 performs regenerative absorption (charging), operates to keep the power voltage constant, and charges the EDLC 14. On the other hand, when the power storage device feed voltage V _dc falls below the discharge reference voltage, the EDLC 14 is discharged and operates to keep the feed voltage constant.

  Next, cooperative control of the regenerative brake 6 and the mechanical brake 7 in the DC electric railway will be described with reference to FIG. As shown in FIG. 4, the brake command from the brake handle 4 is output to the brake control device 5. The brake control device 5 subtracts the regenerative torque generation amount signal in the regenerative brake from the brake command, and calculates the braking force that is insufficient with the regenerative brake 6 alone. The insufficient braking force is supplemented by the mechanical brake 7.

  Therefore, the ratio of the mechanical brake 7 increases as the feeding voltage increases, and when the feeding voltage exceeds a certain voltage (regenerative invalidation voltage), the braking force is provided only by the mechanical brake 7.

  Next, an example of cooperative operation between the electric vehicle 3 and the power storage device 10 will be described with reference to FIG. 5 (distribution method) and FIG. 6 (concentration method).

  The distribution method shown in FIG. 5 is a method in which information is exchanged for each device (electric vehicle 3, power storage device 10), and a control value is determined and controlled for each device based on the information. On the other hand, in the centralized system shown in FIG. 6, information on the devices (electric vehicle 3, power storage device 10) is once collected in the command center 8 that manages the operation, and the control value is determined in the command center 8 based on the information. In this method, a control value is output from the command station 8 to each device.

  Here, the information output from the electric vehicle 3 includes position information (GPS, orbit signal, etc.), regenerative current, punter voltage, regenerative throttling start voltage, regenerative invalidation voltage, regenerative throttling notch (during regenerative), and the like. It is done. The information output from the power storage device 10 includes the charging rate and charging current of the EDLC 14. Furthermore, examples of the control value include a charging reference voltage and a brake notch upper limit.

  FIG. 7 is a configuration diagram of the control unit 50 that controls the semiconductor switching elements 12a and 12b of the bidirectional chopper unit 11 in the embodiment. FIG. 11 is a configuration diagram of a conventional control unit 50.

In FIG. 7, the subtraction unit 51 _obtains the deviation between the _feeding voltage detection value V _{dc of} the power storage device 10 detected by the feeding voltage detection unit 18 and the charging reference voltage value V _dcref, and the normalization calculation unit 52 The deviation is divided by the rated value to obtain a standard calculation output value (for example, when the rated voltage is 2000 V and the input voltage is 1000 V, the standard calculation output value is 0.5). This standard calculation output value is input to the PI amplifier 53 to obtain a current command value as an output. This current command value is input to the limiter 54 and limited to “0 to 1”.

  The current command value limited by the limiter 54 is compared with a new current command value obtained by narrowing the current command value in consideration of the internal resistance value of the EDLC 14 by the filter 56. The current command value is output as the charging current command value.

This charging current command value is calculated by (I _edlc + (V _{edlc_max} −V _edlc ) / R _edlc ) / I _{edlc_max} . Note that I _edlc is a current flowing through the EDLC ₁₄ , V _{edlc_max} is a maximum value of the EDLC voltage V _edlc , and I _{edlc_max} is a maximum value of the EDLC current I _edlc .

  A deviation between the charge current command value output from the comparator 55 and the charge current detection value of the EDLC 14 (detected by the EDLC current detection value 20) is obtained by the deviation unit 57, and the deviation output is output to the PI amplifier 58. The PI amplifier 58 outputs a PI control output that determines the duty of the bidirectional chopper unit 11.

  The PI control output sent from the PI amplifier 58 is limited to “0 to 1” by the limiter 59 and output to the duty amplifier 60. The duty amplifier 60 determines the duty ratio of the bidirectional chopper unit 11. Then, the CMP generator 61 generates a PWM signal corresponding to the duty ratio output from the duty amplifier 60.

  The AND circuit 62 includes, for example, a charge permission condition signal generated by the power storage device 10 when the charging operation is set to the operation mode in FIG. 3, a gate permission condition signal (charge / discharge permission mode), and the traveling electric vehicle 3 (or And an electric circuit presence / absence condition signal determined based on information from the command center 8), and when these charge permission condition signal, gate permission condition signal, and electric vehicle presence / absence condition signal are satisfied, the AND circuit portion thereof The output signal 62 is supplied to the first input terminal of the AND circuit 63. On the other hand, the AND circuit 62 in the conventional control unit 50 uses only the charge permission condition signal and the gate permission condition signal as input signals, and this is different from the present embodiment.

  Further, the PWM signal generated by the CMP generation unit 61 is supplied to the second input terminal of the AND circuit 63. When signals are supplied to both the input terminals, a gate signal for controlling the bidirectional chopper unit 11 is sent from the AND circuit 63, and the bidirectional chopper unit 11 is controlled by the gate signal so that a charging current to the EDLC 14 is supplied. Be controlled.

Here, a method for setting the charging reference voltage V _dcref in the normal state of the first embodiment will be described. In normal times, the charging reference voltage V _dcref is set so that the regenerative throttle of the electric vehicle 3 operates before the charging throttle of the power storage device 10 so that it operates simultaneously even in the slowest case. For that purpose, before the EDLC voltage V _edlc reaches the charge throttle start voltage V _{edlc charge throttle start} of the power storage device 10, the _feeding voltage V _train of the electric vehicle 3 needs to exceed the regenerative throttle operation start voltage V _offset. There is (or need to reach at the same time). That is, the charging reference voltage V _dcref is set as shown in the following equation (1).

Incidentally, a ₁ in the formula (1) from the voltage obtained by multiplying the charging current EDLC14 the internal resistance and the EDLC current detector 20 EDLC14 detects, as the EDLC14 does not become overvoltage by the addition of the voltage Is a variable determined by Vdc2 is a set value for operating the regenerative throttle of the electric vehicle 3 before the charging throttle of the voltage storage device 10.

The above equation (1) will be further described with reference to FIG. FIG. 8 is a diagram for explaining the above equation (1), in which the vertical axis represents the charging reference voltage V _dcref and the horizontal axis represents the EDLC voltage V _edlc .

By multiplying a ₁ corresponding to the inclination by (V _edlc −V _{edlc charge throttle start} ) and adding V _dc2 , two diagonal lines in FIG. 8 (one is V _dc2 > V _offset and the other is V _dc2 = V _offset ). Here, V _dc2 is an intersection of the diagonal line and a straight line indicating the charging throttle start voltage. Therefore, when V _dc2 > V _offset , the regenerative throttle of the electric vehicle 3 always operates before the charging throttle of the power storage device 10. When V _dc2 = V _offset , Dte = 0 and the electric vehicle 3 The regenerative throttle and the charging throttle of the power storage device 10 operate simultaneously.

  Next, the operation of the power storage device 10 in the time zone when the feeding voltage is rising in the early morning and at night will be described separately for “with electric car” and “without electric car”.

[Without electric car]
The power storage device 10 can know the presence or absence of the electric vehicle 3 by obtaining information from the electric vehicle 3 (or the command center 8) by the distribution method (FIG. 5) or the centralized method (FIG. 6). it can. When the electric vehicle 3 is not present, the power storage device 10 suppresses the regenerative absorption operation by increasing the charging start voltage V _dcref as the _feeding voltage V _dc increases.

Further, as described above, the electric vehicle presence / absence condition signal is added to the input signal of the AND circuit 62. Thus, even if the charging reference voltage V _dcref does not rise in time for the rise of the power storage device _feeding voltage V _dc , the condition of the AND circuit 62 is not satisfied when the electric vehicle 3 does not exist, and therefore, regenerative absorption. The operation can be prevented.

[When there is an electric car]
The power storage device 10 obtains information from the electric vehicle 3 (or the command center 8) by the distribution method (FIG. 5) or the centralized method (FIG. 6), and the presence or absence of the electric vehicle 3, and The presence or absence of the electric vehicle regenerative current Ireg can be known. Therefore, when the electric power storage device 10 is “with electric vehicle” and “without regenerative current”, the regenerative absorption operation is prevented by increasing the charging reference voltage V _dcref as the _feeding voltage V _dc increases.

Here, a method for setting the charging reference voltage V _dcref in the case of “no electric car” or “no electric car” and “no regenerative current” in the early morning or at night will be described with reference to FIG. In this case, the charging reference voltage V _dcref is set using the following equation (2) instead of the above equation (1).

The above equation (2) is obtained by adding V _off2 to V _dcs of the above equation (1). V _off2 From the measured values V _{dc measurements} of the electric power storage device feeding circuit voltage V _dc, a value obtained by subtracting the reference value V _{dc unloaded reference value} of the electric power storage device feeding circuit voltage V _dc at the time of no load. That is, V _off2 is a value that increases as the power storage device _feeding voltage V _dc increases. Therefore, when the V _dcs + V _off2 as the charging reference voltage V _DCREF is output, the charging reference voltage V _DCREF becomes possible to increase with increasing power storage device feeding circuit voltage V _dc.

Also, when a ₁ × (V _edlc −V _{edlc charge start} ) + V _dc2 is output as the charging reference voltage V _dcref, as in the formula (1), if V _dc2 > V _offset , be sure to When the regenerative throttle of the vehicle 3 operates before the charging throttle of the power storage device 10 and V _dc = V _offset , the regenerative throttle of the electric vehicle 3 and the charging throttle of the power storage device 10 operate simultaneously with Dte = 0. Will be.

On the other hand, the power storage device 10 sets an appropriate charging reference voltage V _dcref according to the distance Dte between the electric vehicle 3 and the power storage device 10 and the regenerative current Ireg when “there is an electric vehicle” and “there is a regenerative current”. To do.

The charging reference voltage V _{dcref in} this case can be calculated by the following equation (3), for example.

As shown in the above equation (3), the regenerative power can be absorbed by the power storage device 10 by setting the charging reference voltage V _dcref .

As in the first embodiment, by setting the charging reference voltage V _dcref , when the electric vehicle 3 does not exist or when the electric vehicle 3 exists and there is no regenerative current Ireg, the charging reference voltage V _dcref is Since the power storage device rises as the _feeding voltage V _dc rises, it is possible to suppress unnecessary operations for absorbing feeding voltage that is not regenerative power.

Even if the charging reference voltage V _dcref does not rise in time with respect to the rise of the power storage device _feeding voltage V _dc , the condition of the AND circuit 62 is not satisfied when the electric vehicle 3 does not exist. Unnecessary operations for absorbing feeding voltage can be prevented.

Furthermore, when the electric vehicle 3 is regenerated and the power storage device _feeding voltage V _dc is high, the regenerative power can be absorbed by the power storage device 10. As a result, regenerative invalidation of the electric vehicle 3 is suppressed, mechanical brake operation is increased, and wear of parts such as a brake disk can be suppressed.

[Embodiment 2]
The power storage device 10 according to the second embodiment will be described. The power storage device 10 according to the second embodiment is an embodiment other than the method for setting the charging reference voltage V _dcref in the case of “no electric car” or “with an electric car” and “no regenerative current” in the early morning or at night. Same as 1.

Embodiment 2, when EDLC voltage V _EDLC is greater than V _{EDLC 2,} a charging reference voltage V _DCREF the following formula (4), if EDLC voltage V _EDLC is less than V _{EDLC 2} is a charging reference voltage V _DCREF below (5) Formula. V _edlc2 is a reference point for selecting the following formula (4) or the following formula (5), and is set to a preset value.

V _offset of equation (4) _{- (V dcs + V off2)} / V edlc -V edlc2 corresponds to the slope of the oblique line in FIG. 10. By multiplying this inclination by V _edlc −V _{edlc charge throttle start} and adding V _dcs + V _off2 , a value corresponding to the diagonal line of the graph of FIG. 10 is obtained. In the second embodiment, since V _dc2 = V _offset , the regeneration throttle start of the electric vehicle 3 and the charge throttle start of the power storage device 10 operate simultaneously with Dte = 0.

In the case of the above expression (5), the charging reference voltage V _dcref is raised as the _feeding voltage V _dc increases, as in the first embodiment.

Thus, by setting the charging start voltage V _dcref , the same effects as those of the first embodiment can be obtained.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

For example, in the embodiment 2, so that the V _dc2 = V _offset, but setting the charging reference voltage V _DCREF, may set the charging reference voltage V _DCREF such that V _dc2 ≧ V _offset.

DESCRIPTION OF SYMBOLS 1 ... Feed wire 3 ... Electric vehicle 10 ... Power storage device 11 ... Bidirectional chopper 14 ... Electric storage means (EDLC)
50 ... Control unit V _dc ... _Feed voltage V _dcref ... Charging reference voltage Ireg ... Regenerative current Dte ... Power storage device-electric vehicle distance

Claims (4)

When the feeding voltage is equal to or higher than the charging reference voltage, the charging voltage is charged to the power storage means via the bidirectional chopper, and when the feeding voltage is equal to or lower than the discharging reference voltage, the power storage means is connected to the feeder via the bidirectional chopper. A power storage device for a DC electric railway that suppresses voltage drop and voltage rise of the feeding voltage by discharging,
The control unit of the bidirectional chopper is
When there is no electric vehicle in the early morning and at night, and when there is an electric vehicle but no regenerative current is generated, the charging reference voltage is increased according to the increase of the feeding voltage,
In the early morning and at night, when an electric vehicle exists and a regenerative current is generated from the electric vehicle, the charging reference voltage is set according to the distance and the regenerative current between the power storage device and the electric vehicle. DC electric railway power storage device. The control unit of the bidirectional chopper is
2. The charge reference voltage is calculated by the following equation (2) when there is no electric vehicle in the early morning and at night, and when there is an electric vehicle but no regenerative current is generated. The electric power storage apparatus of the described DC electric railway.

The control unit of the bidirectional chopper is
In the early morning and at night, when the electric vehicle is not present and when the electric vehicle is present but no regenerative current is generated, the charging reference voltage is calculated by the following equations (4) and (5). The power storage device for a DC electric railway according to claim 1.

The control unit of the bidirectional chopper is
The presence or absence of a traveling electric vehicle is determined based on information from the traveling electric vehicle or the headquarters, and charging is not started when there is no traveling electric vehicle. DC electric railway power storage device.

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