JP5493604B2 - DC electric railway power storage device - Google Patents

Description

  The present invention relates to a charging current restrictor for a power storage device used in a DC electric railway.

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

  As such an electric power storage apparatus, the thing of patent document 1 is known, for example. Patent Document 1 describes a power storage device that absorbs regenerative power of an electric vehicle by EDLC. A feature of the power storage device of Patent Document 1 is that it has a function of increasing the electric voltage in response to an increase in the voltage of the EDLC, and as a result, a regenerative current restriction (hereinafter referred to as a regenerative restriction) of an electric vehicle. The point is to encourage.

Japanese Patent Application Laid-Open No. 2007-106186.

  In general, the regenerative brake can be controlled at a constant torque, and the notch (stage) is switched when the electric voltage exceeds the regenerative throttle voltage, and a brake of the combined use such as an aerodynamic brake is used for the insufficient brake force. That is, the diaphragm does not always advance as the voltage increases. Therefore, when only the primary side voltage of the bidirectional chopper is increased, the regenerative restriction proportional to the voltage as shown in FIG. 2 of Patent Document 1 is not actually performed, and the regenerative current flows even if the feeding voltage is increased. to continue. Therefore, the following problems occur. One is that the EDLC is fully charged and suddenly stops charging, and the punt point voltage (in the present invention, the feeding voltage of the electric car) rises at a stretch, which exceeds the regenerative invalidation voltage and the electric car becomes regenerative and invalidated. Or, since it suddenly switches to mechanical braking, the ride comfort may deteriorate. The other is that when the regenerative current is reduced and the electric vehicle is regeneratively expired, a relatively large regenerative current is lost due to the revocation, so the terminal voltage of the EDLC decreases greatly after the charge is stopped, and the energy charge of the EDLC is small. It is a problem.

  This invention is made | formed based on the said subject, and it is providing the electric power storage apparatus of the direct current electric railway which is hard to carry out regeneration invalidation.

In order to solve the above-described problem, the present invention is provided between a feeder line and a rail serving as a return line of the feeder line, and has a bidirectional chopper portion to control charging of regenerative power from an electric vehicle. DC / DC conversion means, power storage means for charging power controlled by the DC / DC conversion means, current detection means for detecting current flowing from the DC / DC conversion means to the power storage means, and a voltage detection means, and a DC electric railway power storage device having a gas collector voltage detection means for detecting gas collector voltage for detecting voltage, control means for charging controlling the DC / DC converting means, the electrical The difference between the voltage of the power storage means detected by the voltage detection means and the voltage at which the power storage means starts charging throttling is added to the voltage set larger than the feeding voltage at which the car starts regenerative throttling. Obtained A voltage determined so that the power storage means does not become an overvoltage by the addition, or a voltage at which the power storage means starts charging, whichever is greater is determined as a feeding reference voltage, {Iedlc + (Vedlc_max−Vedlc) in consideration of the current command value generated based on the deviation between the feeding voltage detected by the feeding voltage detection means and the determined feeding reference voltage and the internal resistance value of the power storage means. ) / Redlc} / Iedlc_max (Iedlc is the detection current of the current detection means, Vedlc is the detection voltage of the voltage detection means, Redlc is the internal resistance of the power storage means, Vedlc_max is the maximum value of Vedlc, and Iedlc_max is the maximum value of Iedlc) Of the current command values generated by calculating The duty ratio of the bidirectional chopper unit is determined based on a deviation between the charging current command value and the charging current detection value of the power storage means detected by the current detection means, and the determined duty ratio is set as a command value. The bidirectional chopper unit is controlled by a matched PWM signal .

  The power storage means is an EDLC.

  According to the above configuration, the feeding reference voltage input to the control means is calculated by the equation (2). As a result, the regenerative throttle of the electric vehicle is less likely to reach regenerative invalidity by operating simultaneously even at the slowest speed before the charging throttle of the power storage device regardless of the distance between the electric vehicle and the power storage device.

According to the first and second aspects of the present invention, the feeding reference voltage input to the control means is calculated by the equation (2). As a result, the regenerative throttle of the electric vehicle is less likely to reach regenerative invalidity by operating simultaneously even at the slowest speed before the charging throttle of the power storage device regardless of the distance between the electric vehicle and the power storage device.

Schematic at the time of using an electric power storage apparatus for DC electric railway. The block diagram of an electric power storage apparatus. The block block diagram of the control part which employ | adopted the charging current aperture used by this invention. Explanatory drawing in case an electric power storage apparatus charge aperture operates before an electric vehicle regeneration aperture. Explanatory drawing in case an electric vehicle regeneration aperture and a power storage device charging aperture operate simultaneously. Explanatory drawing in case an electric vehicle regenerative aperture operates before a power storage device charging aperture. Explanatory drawing for demonstrating Formula (2).

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

  FIG. 1 is a schematic diagram when the power storage device is used in a DC electric railway. FIG. 1 illustrates a feeder 1, an electric vehicle 3 that is supplied with electric 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. .

  In recent years, there are many vehicles equipped with a regenerative brake in the electric vehicle 3, and a feeding voltage (hereinafter referred to as an electric vehicle feeding voltage) of a feeder line where the electric vehicle 3 is located is monitored during operation of the regenerative brake. A device (not shown) is provided that prevents an excessive increase in feeding voltage by narrowing the regenerative current from 100% to 0% according to the voltage when the voltage is equal to or higher than a specified value.

  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. A smoothing reactor 13 is provided. The other end of the smoothing reactor 13 is connected to one end of the EDLC 14, and the other end of the EDLC 14 is connected to the rail 2.

  The bidirectional chopper unit 11 corresponds to DC / DC conversion means, and the EDLC 14 corresponds to power storage means.

  Here, Vtrain in FIG. 1 is an electric vehicle feeding voltage, Vdc is a feeding voltage of a feeder line in which the power storage device 10 is located, Vedlc is a voltage of the EDLC 14, and Ireg is a charge charged by the power storage device 10. The regenerative current from the electric car 3 flowing through the electric wire 1 is assumed, R is the feeding resistance of the feeder 1 equivalently expressed, and Dte is the distance between the electric car 3 and the power storage device 10.

  The power storage device 10 will be described with reference to FIG.

  In addition to the bidirectional chopper unit 11 and the EDLC 14, the power storage device 10 includes a feeding current detector 15, a filtering reactor 16, a filtering capacitor 17, a feeding voltage detector 18, an EDLC voltage detector 19, and an EDLC current detector. 20 is provided. The feeding voltage detector 18 corresponds to feeding voltage detection means, the EDLC voltage detector 19 corresponds to voltage detection means, and the EDLC current detector 20 corresponds to current detection means.

  Between the feeder 1 and the rail 2, a filter reactor 16 and a filter capacitor 17 are connected in series. The feeder current detector 15 is provided on the connection line of the filter reactor 16 to the feeder line 1, and the feeder voltage detector 18 is connected to a common connection point between the feeder line 1 and the filter reactor 16. The other end is connected to the rail 2.

  The EDLC voltage detector 19 has one end connected to a common connection point between the smoothing reactor 13 and the EDLC 14 and the other end connected to the rail 2. The EDLC current detector 20 is provided at a common connection point between the smoothing reactor 13 and the EDLC 14.

  FIG. 3 shows a control unit 50 that controls charging of regenerative power using a charging current restrictor (hereinafter referred to as a charging restrictor) using a filter 56 that controls the semiconductor switching elements 12 a and 12 b of the bidirectional chopper unit 11. It is a control block block diagram of. The control unit 50 corresponds to a control unit.

  In FIG. 3, the feed voltage detection value of the power storage device 10 detected by the feed voltage detector 18 (hereinafter referred to as the power storage feed voltage) Vdc and the power reference voltage value (the feed of the power storage device 10). The deviation from the electric voltage command value) Vdcref is obtained by the deviation unit 51, the deviation output of the deviation unit 51 is input to the standardization calculation unit 52, and the value input by the standard calculation unit 52 is divided by the rated value. The standard calculation output value (for example, when the rated voltage is 2000V and the input voltage is 1000V, the standard calculation output value is 0.5) is obtained. This 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 the new current command value narrowed down by the filter 56 that narrows down the current command value in consideration of the internal resistance value of the EDLC 14, and the smaller one is compared. The current command value is output as the charging current command value. This charging current command value is calculated by (Iedlc + (Vedlc_max−Vedlc) / Redlc) / Iedlc_max. Note that Iedlc is a current flowing through the EDLC 14, Redlc is an internal resistance of the EDLC 14, Vedlc_max is a maximum value of Vedlc, and Iedlc_max is a maximum value of Iedlc.

  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 detector 20) is obtained by the deviation unit 57, and the deviation output is supplied to the PI amplifier 58, where PI The amplifier 58 sends out 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 input to the DUTY amplifier 60 that controls the duty ratio of the bidirectional chopper unit 11. The CMP generator 61 generates a PWM signal corresponding to the duty ratio output from the DUTY amplifier 60.

  The AND circuit unit 62 is supplied with a charge permission condition signal and a gate permission condition signal (charge / discharge permission mode) sent from a system (not shown) when regenerative power is generated, and these charge permission condition signal and gate permission condition are supplied. When the signal is satisfied, the output signal from the AND circuit unit 62 is supplied to the first input terminal of the AND circuit unit 63. Further, the PWM signal generated by the CMP generation unit 61 is supplied to the second input terminal of the AND circuit unit 63. When signals are supplied to both of these input terminals, the gate signal is given to the bidirectional chopper unit 11 from the output of the AND circuit unit 63, and the semiconductor switching elements 12a and 12b of the bidirectional chopper unit 11 are controlled. .

  Next, the operation will be described.

  FIG. 4 shows the time variation of each voltage when the charging throttle of the power storage device 10 operates before the regenerative throttle of the electric vehicle 3. The items of each voltage on the vertical axis are, in order from the top, the regenerative throttle start voltage Voffset of the electric vehicle 3, the electric vehicle feed voltage Vtrain and the power storage feed voltage Vdc, and the charge upper limit voltage of the EDLC 14 (Vedlc charge throttle start voltage). , EDLC voltage Vedlc and regenerative current Ireg charged by power storage device 10.

  The time change of each voltage is as follows.

  When the regenerative current Ireg flows, the EDLC voltage Vedlc rises, and the voltage of the EDLC 14 reaches the Vedlc charge throttle start voltage which is the charge throttle start EDLC voltage of the power storage device 10, the charge throttle of the power storage device 10 operates.

  In this case, since the regenerative power charged by the power storage device 10 is less than the regenerative power of the electric vehicle 3, the voltage of the feeder line 1 is increased. As a result, the regenerative throttle of the electric vehicle 3 starts to operate due to the voltage rise of the feeder line 1. At this time, if the voltage rise of the feeder 1 is steep, the voltage rise may not be suppressed, leading to regenerative invalidation.

  Here, the formula Vtrain−Vdc = Ireg × Rrail described in FIG. 4 will be described.

From FIG. 1, the electric vehicle voltage Vtrain during regeneration can be expressed by the following equation.
Vtrain = Vdc + Ireg × Rline × Dte (1)
When Rrail = Rline × Dte,
Vtrain−Vdc = Ireg × Rrail, which is the mathematical formula shown in FIG.

  FIG. 5 shows the time variation of each voltage when the regenerative throttle of the electric vehicle 3 and the charging throttle of the power storage device 10 operate simultaneously. The item of voltage is the same as FIG. Therefore, the description of the parts common to FIG. 4 is omitted.

  Since the regenerative power charged by the power storage device 10 is equal to the regenerative power of the electric vehicle 3, the voltage of the feeder line 1 can be suppressed to be substantially constant after the operation of each throttle.

  FIG. 6 is a time change of each voltage when the charging throttle of the power storage device 10 operates after the regenerative throttle of the electric vehicle 3 operates. The item of voltage is the same as FIG. Therefore, the description of the parts common to FIG. 4 is omitted.

  In this case, since the regenerative power charged by the power storage device 10 is greater than or equal to the regenerative power of the electric vehicle 3, the voltage of the feeder 1 does not increase. Thereafter, when the charging throttle of the power storage device 10 starts to operate, the regenerative power to be temporarily charged by the power storage device 10 ≦ the regenerative power of the electric vehicle 3, but since the regenerative throttle on the electric vehicle 3 side is already operating. The voltage of the feeder 1 is difficult to increase.

  Therefore, it is necessary to set the power storage device 10 so that the regenerative throttle of the electric vehicle 3 operates before the charging throttle of the power storage device 10 so as to operate simultaneously even in the slowest case as shown in FIGS. is there. For this purpose, the feeding voltage of the electric vehicle 3 needs to exceed the operation start voltage Voffset of the regenerative throttle before the voltage Vedlc of the EDLC 14 reaches the Vedlc charge throttle start voltage that is the charge throttle start EDLC voltage of the power storage device 10. There is. Therefore, in the present invention, the feeding reference voltage Vdcref input to the control unit 50 is set as follows.

  From equation (1), when Dte = 0, Rline × 0 = 0, that is, Vtrain = Vdc. When Dte is other than 0, Vtrain> Vdc is always satisfied when the electric vehicle 3 is regenerated.

Here, Vdc ′ calculated by Equation (2) is adopted as the feeding reference voltage Vdcref.
Vdc ′ = max (a1 × (Vedlc−Vedlc _{charge throttle start} ) + Vdc2, Vdcs) (2)
Then, when Dte = 0, the power storage device 10 operates so that the regeneration throttle of the electric vehicle 3 and the charging throttle of the power storage device 10 operate simultaneously. At the time of regeneration, Vtrain> Vdc is always established, and the regeneration throttle of the electric vehicle 3 operates first.

Note that a1 is a variable determined from the voltage obtained by multiplying the internal resistance of the EDLC 14 and the charging current of the EDLC 14 detected by the EDLC current detector 20 so that the EDLC 14 does not become an overvoltage by adding the voltage. Vedlc is the voltage of the EDLC 14 detected by the EDLC voltage detector 19, and Vedlc _{charge throttle start} is the voltage of the EDLC 14 at which the _{charge throttle} of the power storage device 10 is _{started, which} is the charge upper limit voltage of the EDLC 14. Voffset is a feeding voltage at which the electric vehicle 3 starts regenerative throttling. However, since the starting power supply voltage of the regenerative throttle differs depending on the electric vehicle 3, the highest starting power voltage of the regenerative throttle among the electric vehicles 3 is used. Vdc2 is a feeding voltage equal to or higher than Voffset. Vdcs is a feeding voltage at which the power storage device 10 starts charging. max (x, y) outputs a larger voltage of x and y.

From equation (2), the larger value of a1 × (Vedlc−Vedlc _{charge restriction start} ) + Vdc2 or Vdcs, whichever is greater, is input to the deviation unit 51 as the feeding reference voltage Vdcref.

  Expression (2) will be further described with reference to FIG. FIG. 7 is a diagram for explaining the expression (2), where the vertical axis represents the feeding reference voltage (Vdc ′) and the horizontal axis represents the EDLC voltage. Items on the vertical axis are, in order from the top, the regeneration invalidation voltage of the electric vehicle 3 or the overvoltage of the electric vehicle 3, the regenerative throttle start voltage Voffset of the electric vehicle 3, and the charging start voltage Vdcs of the power storage device 10. The horizontal axis represents the overvoltage of the EDLC 14 and the Vedlc charge throttle start voltage (charge upper limit voltage of the EDLC 14) which is the charge throttle start EDLC voltage of the power storage device 10 in order from the right.

  The two diagonal lines in the figure are when one of Vdc2> Voffset and the other when Vdc2 = Voffset. The inclination of this oblique line is a1. When Vdc2 = Voffset is set so as to pass through the intersection of Voffset and the charging throttle start voltage of the power storage device 10, the regeneration throttle of the electric vehicle 3 and the charging throttle of the power storage device 10 operate simultaneously at Dte = 0. When Vdc2> Voffset, the regenerative aperture of the electric vehicle 3 always operates first. Vdc2 is an intersection of the oblique line and a straight line indicating the charging throttle start voltage.

  Thus, the feeding reference voltage Vdcref input to the control unit 50 is calculated by the equation (2). As a result, the regenerative throttle of the electric vehicle 3 operates at the same time, at the latest, before the charging throttle of the power storage device 10 regardless of the distance between the electric vehicle 3 and the power storage device 10. As a result, immediately after the regenerative throttle of the electric vehicle 3 operates, the regenerative power charged by the power storage device 10 is greater than or equal to the regenerative power from the electric vehicle 3. After that, even if the charging throttle of the power storage device 10 operates, it becomes difficult to reach regenerative expiration because it becomes as described with reference to FIGS.

  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, the power storage means may be a storage battery.

DESCRIPTION OF SYMBOLS 1 ... Feed wire 2 ... Rail 3 ... Electric vehicle 10 ... Electric power storage device 11 ... Bidirectional chopper part 12a, 12b ... Semiconductor switching element 13 ... Smoothing reactor 14 ... EDLC (electric double layer capacitor)
DESCRIPTION OF SYMBOLS 15 ... Feed current detector 16 ... Filter reactor 17 ... Filter capacitor 18 ... Feed voltage detector 19 ... EDLC voltage detector 20 ... EDLC current detector 50 ... Control part 51, 57 ... Deviation part 52 ... Standard calculation Units 53, 58 ... PI amplifiers 54, 59 ... Limiter 55 ... Comparator 56 ... Filter 60 ... DUTY amplifier 61 ... CMP generators 62, 63 ... AND circuit

Claims (2)

DC / DC conversion means provided between a feeder line and a rail serving as a return line of the feeder line, and having a bidirectional chopper portion to control charging of regenerative power from an electric vehicle, the DC / DC conversion means, A power storage means for charging the charge-controlled power, a current detection means for detecting a current flowing from the DC / DC conversion means to the power storage means, a voltage detection means for detecting the voltage of the power storage means, and a feeding voltage A power storage device for a DC electric railway equipped with a feeding voltage detecting means for detecting,
The control means for controlling the charging of the DC / DC converting means is:
The difference between the voltage of the power storage means detected by the voltage detection means and the voltage at which the power storage means starts charging throttling is added to the voltage set larger than the feeding voltage at which the electric vehicle starts regenerative throttling. The voltage obtained by the addition is determined so that the power storage means does not become an overvoltage, or the voltage at which the power storage means starts charging, whichever is greater is used as the power supply reference voltage. Decide
Considering the current command value generated based on the deviation between the feed voltage detected by the feed voltage detection means and the determined feed reference voltage and the internal resistance value of the power storage means, {Iedlc + (Vedlc_max−Vedlc ) / Redlc} / Iedlc_max (Iedlc is the detection current of the current detection means, Vedlc is the detection voltage of the voltage detection means, Redlc is the internal resistance of the power storage means, Vedlc_max is the maximum value of Vedlc, and Iedlc_max is the maximum value of Iedlc) The smaller current command value among the current command values generated by calculating the charging current command value,
A duty ratio of the bidirectional chopper unit is determined based on a deviation between the charging current command value and a charging current detection value of the power storage means detected by the current detection means, and a PWM signal corresponding to the determined duty ratio The bidirectional chopper unit is controlled by the DC electric railway power storage device.   2. The DC electric railway power storage device according to claim 1, wherein the power storage means is an EDLC.

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