JP2005206111A - Dc voltage power feed device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To re-utilize regeneration power of an electric vehicle. <P>SOLUTION: The DC voltage power feed device is provided with an electricity storage element 15 for storing power fed through a DC wire 3; a charge/discharge circuit 14 for performing charge/discharge action of the electricity storage element 15; a control circuit 16 for controlling the charge/discharge circuit 14; a voltage detector 17 for detecting DC voltage of an output end of the charge/discharge circuit 14 and outputting it to the control circuit 16 as DC voltage signal; a current detector 18 for detecting current outputted to the electric vehicle 10 side and outputting it to the control circuit as an output current signal; and a current detector 19 for detecting the charge/discharge current of the electricity storage element 15 and outputting it to the control circuit 16 as a charge/discharge current signal. The control circuit 16 charge-controls the electricity storage element when the DC voltage signal exceeds a charge set value and controls discharge-controls the electricity storage element when the DC voltage signal exceeds a discharge set value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a direct-current voltage power supply apparatus configured to reuse regenerative power of an electric vehicle.

  In general, in a DC voltage power supply apparatus, an AC voltage is converted into a DC voltage by a diode rectifier to supply DC power to an electric vehicle. FIG. 12 shows a conventional DC voltage feeder. In FIG. 12, 1 is an AC power source, 2 is a rectifier, 3 is a DC overhead wire, 4 is an inverter, 5 is an AC motor, 6 is a filter reactor, 7 is a filter capacitor, 8 is a resistor, 9 is a switch, 10 is an inverter 4 And an AC motor 5, a filter reactor 6, a filter capacitor 7, a resistor 8, and a switch 9.

  A conventional DC voltage feeder will be described. The AC voltage of the AC power supply 1 is converted from an AC voltage to a DC voltage by the rectifier 2 and fed to the electric vehicle 10 via the DC overhead wire 3 (see, for example, Non-Patent Document 1).

The electric vehicle 10 converts the DC voltage into an AC voltage by the inverter 4 to drive the AC motor 5. In the power running operation in which power is consumed by the AC motor 5, the AC motor 5 receives power from the DC overhead wire 3 → the inverter 4 → the AC motor 5, and in the regenerative operation in which the AC motor 5 generates power, the AC motor 5 is the AC motor. 5. Regenerative power is output from the inverter 4 to the DC overhead line 3. When the electric power output to the DC overhead line 3 is operated by another electric vehicle on the same DC overhead line 3, the regenerative power is consumed by the other electric vehicle performing the power operation and the power can be used effectively. it can.
Yoshifumi Mochinaga “Electrical Railway Engineering” Ace Publishing 1999, page 62

  However, in the conventional DC voltage power supply device, when there is no other electric vehicle that performs a power running operation when the electric vehicle is performing a regenerative operation, the DC voltage of the DC overhead line increases. When the DC voltage of the DC overhead line exceeds the set value of the overvoltage, the switch of the electric vehicle that performs the regenerative operation is turned on, and regenerative power is consumed by the resistor to suppress the overvoltage of the DC overhead line. For this reason, there is a problem that the regenerative power is wasted.

  Therefore, the present invention connects the charge / discharge circuit and the storage element in parallel with the DC overhead line, charges the storage element with the voltage rise of the DC overhead line, and discharges the storage element with the output current to the electric vehicle. It is an object of the present invention to provide a DC voltage power supply device that can recycle regenerative power.

  In order to achieve the above object, the present invention provides an electric power supplied via a DC overhead line in a DC voltage feeder that converts an AC voltage into a DC voltage and supplies the DC voltage to an electric vehicle via the DC overhead line. A storage element for storing the charge, a charging / discharging circuit for charging / discharging the storage element, a control circuit for controlling the charging / discharging circuit, and detecting a DC voltage at the output terminal of the charging / discharging circuit to the control circuit A voltage detector that outputs as a DC voltage signal, a current detector that detects the current output to the electric vehicle and outputs it as an output current signal to the control circuit, and detects the charge / discharge current of the storage element and charges the control circuit Provided with a current detector that outputs as a discharge current signal, the control circuit controls charging of the storage element when the DC voltage signal exceeds the charge setting value, while discharging the storage element when the DC voltage signal exceeds the discharge setting value To control It is characterized in.

  According to the present invention having the above-described configuration, the regenerative power of the electric vehicle can be reused because the regenerative power of the electric vehicle is charged in the power storage element and discharged by powering operation. In addition, since the storage element is charged by looking at the magnitude of the DC overhead line voltage, an increase in the overhead line voltage can be quickly suppressed.

<< First Embodiment >>
FIG. 1 is a circuit configuration diagram showing a first embodiment of a DC voltage supply apparatus according to the present invention. In the figure, AC power supply 1, rectifier 2, DC overhead line 3, inverter 4, AC motor 5, filter reactor 6, filter capacitor 7, resistor 8, switch 9, inverter 4, AC motor 5, filter reactor 6, and filter capacitor 7 are shown. Since the electric vehicle 10 including the resistor 8 and the switch 9 has the same configuration as the conventional drawing shown in FIG.

  In FIG. 1, 11a and 11b are self-extinguishing elements, 12 is a reactor, 13 is a DC capacitor, 14 is a charge / discharge circuit composed of the self-extinguishing elements 11a and 11b, a reactor 12 and a DC capacitor 13, and 15 is a power storage. Element 16 is a control circuit for controlling the charging / discharging circuit 14, 17 is a voltage detector for detecting a DC capacitor voltage, 18 is a current detector for detecting a current output to the DC overhead wire 4, and 19 is a storage element 15. It is a current detector for detecting a charge / discharge current. The charge / discharge circuit 14 is connected in parallel with the DC overhead line 3, and the control circuit 16 controls the self-extinguishing elements 11 a and 11 b to charge and discharge the storage element 15.

  Next, the circuit operation of the control circuit 16 will be described with reference to FIGS.

  FIG. 2 shows a control function block of the control circuit 16 and is a control block diagram of a charge / discharge switching circuit for switching between charge and discharge control modes. In FIG. 2, 20 is a charge control unit, 21 is a discharge control unit, 22 is a gate circuit, 23 is a charge / discharge determination circuit, and 24 is a switching circuit.

  The operation of FIG. 2 will be described. The DC capacitor voltage signal Vdc obtained from the voltage detector 17 is compared with the charge level Level_H and the discharge level Level_L by the charge / discharge determination circuit 23. If the DC capacitor voltage signal Vdc exceeds the charge level Level_H, the switching circuit 24 controls the charge controller. A signal is output from 20 to the gate circuit 22, and when the DC capacitor voltage signal Vdc falls below the discharge level Level_L, the switching circuit 24 outputs a signal from the discharge control unit 21 to the gate circuit 22.

  FIG. 3 shows a control block diagram of the discharge controller 21. In FIG. 3, 25 is a subtractor, 26 is an amplifier, 27 is a limit circuit, 28 is a subtractor, 29 is a current control circuit, 30 is a triangular wave generation circuit, and 31 is a PWM circuit.

  The operation of FIG. 3 will be described. The output current signal Io obtained from the current detector 18 subtracts the output current set value Io_L by the subtractor 25, amplifies it by the amplifier 26, performs limit processing by the limit circuit 27, and outputs the discharge current command Ib *. Generate. The subtractor 28 subtracts the discharge current command Ib * and the charge / discharge current signal Ib obtained from the current detector 19, and the output signal is calculated by the current control circuit 29 to be an input signal of the PWM circuit 31. The PWM circuit 31 compares the output signal of the current control circuit 29 with the output signal of the triangular wave generation circuit 30 and outputs a discharge control output signal.

  FIG. 4 shows a control block diagram of the charge control unit. In FIG. 4, reference numeral 32 denotes a charging operation determination circuit.

  The operation of FIG. 4 will be described. The DC capacitor voltage signal Vdc obtained from the voltage detector 17 is compared with the charging operation level LevelC by the charging operation determination circuit 32. When the DC capacitor voltage signal Vdc exceeds the charging operation level LevelC, the upper side of the charging / discharging circuit 14 is detected. The self-extinguishing element 11a is turned on to charge the storage element 15, and when the DC capacitor voltage signal Vdc is below the charging operation level LevelC, the upper self-extinguishing element 11a of the charge / discharge circuit 14 is turned off to store the storage element. 15 stops charging. In the charge control unit, the lower self-extinguishing element 11b is always turned off and the storage element 15 is controlled not to be discharged.

  As described above, according to the first embodiment, the storage element 15 can be charged by increasing the overhead line voltage, and the storage element 15 can be discharged by increasing the output current to the overhead line 3. As a result, the regenerative power of the electric vehicle 10 is charged in the power storage element 15 and discharged in the power running operation, so that the regenerative power of the electric vehicle 10 can be reused. Moreover, since the electrical storage element 15 is charged in view of the magnitude of the DC overhead line voltage, an increase in the overhead line voltage can be quickly suppressed.

<< Second Embodiment >>
FIG. 5 is a circuit configuration diagram showing a second embodiment of the DC voltage feeding device according to the present invention. Reference numeral 33 denotes a reactor, 34 denotes a switch, and 35 denotes an open / close circuit constituted by the reactor 33 and the switch 34.

  The circuit operation of FIG. 5 will be described. The charge / discharge circuit 14 is connected to a DC capacitor 13 at the output end. When a short circuit fault and a ground fault occur in the DC overhead line 3 in a state where the DC capacitor 13 is directly connected to the DC overhead line 3, the stored energy of the DC capacitor 13 or the storage element 15 is released through the failure point. Since this discharge energy may increase the number of accidents, when a short circuit fault or a ground fault occurs in the DC overhead line, the switch 34 is quickly opened to stop the energy release. In this case, the reactor 33 has an effect of suppressing the increase rate of the short circuit current.

  As described above, according to the second embodiment, even when a short-circuit fault or a ground fault occurs in the DC overhead line 3, it is possible to suppress the release of energy by opening the switch 34, and to make the DC voltage supply device safe. Can be operated.

  Further, the power storage element 15 and the charge / discharge circuit 14 can be disconnected from the DC overhead line 3 by opening the switch 34 without being limited to when an accident occurs.

<< Third Embodiment >>
FIG. 6 is a control block diagram showing a third embodiment of the DC voltage supply apparatus according to the present invention. In FIG. 6, reference numeral 36 denotes a charging operation determination circuit having hysteresis characteristics.

  The operation of FIG. 6 will be described. The DC capacitor voltage signal Vdc obtained from the voltage detector 17 is compared with the charging operation upper level LevelC_H and the charging operation lower level LevelC_L by the charging operation determination circuit 36, and the DC capacitor voltage signal Vdc exceeds the charging operation upper level LevelC_H. When the upper self-extinguishing element 11a of the charging / discharging circuit 14 is turned on to charge the storage element 15, and the DC capacitor voltage signal Vdc is below the charging operation lower level LevelC_L, the upper self-extinguishing element 11a of the charging / discharging circuit 14 is charged. The arc-shaped element 11a is turned off and charging of the electricity storage element 15 is stopped.

  As described above, according to the third embodiment, since the charging operation determination circuit 36 has hysteresis characteristics, the phenomenon that the switching frequency of the self-extinguishing elements 11a and 11b increases at the threshold value of the charging determination does not occur. The storage element can be charged by increasing the overhead line voltage, and the storage element can be discharged by increasing the output current to the overhead line. Therefore, the regenerative power of the electric vehicle 10 can be recharged by charging the regenerative power of the electric vehicle 10 with a power storage element and discharging it by powering operation.

<< Fourth Embodiment >>
FIG. 7 is a circuit configuration diagram showing a fourth embodiment of the DC voltage feeding device according to the present invention. In FIG. 7, reference numeral 37 denotes a voltage detector that detects the terminal voltage of the storage element 15.

  FIG. 8 shows a control block diagram of the control circuit 16. 8, 38 is a full charge determination circuit, 39 is a low voltage determination circuit, 40 is a charge stop unit, 41 is a discharge stop unit, 42 is a charge stop switching circuit, and 43 is a discharge stop switching circuit.

  The operation of FIG. 8 will be described. The terminal voltage signal Vb of the storage element 15 obtained from the voltage detector 37 is input to the full charge determination circuit 38 and the low voltage determination circuit 39. The full charge determination circuit 38 compares the terminal voltage signal Vb and the full charge set value Level_P. When the terminal voltage signal Vb exceeds the full charge set value Level_P, the charge stop switching circuit 42 is changed from the charge control unit 20 to the charge stop unit 40. Switching and charging operation of the storage element 15 are stopped. The low voltage determination circuit 39 compares the terminal voltage signal Vb with the low voltage set value Level_N, and when the terminal voltage signal Vb falls below the low voltage set value Level_N, the discharge stop switching circuit 43 from the discharge control unit 21 to the discharge stop unit 41. And the discharging operation of the storage element 15 is stopped.

  As described above, according to the fourth embodiment, the regenerative electric power of the electric vehicle 10 is charged by the electric storage element without discharging an overvoltage or a voltage drop in the electric storage element 15, and discharged by the power running operation. Regenerative power can be reused.

<< Fifth Embodiment >>
FIG. 9 is a control block diagram showing a fifth embodiment of the DC voltage feeding device according to the present invention. In FIG. 9, reference numeral 44 denotes a full charge determination circuit having a hysteresis characteristic, and reference numeral 45 denotes a low voltage determination circuit having a hysteresis characteristic. Since the full charge determination circuit 44 and the low voltage determination circuit 45 have hysteresis characteristics, when the charge / discharge current stops after the determination of full charge or voltage drop, the voltage increase / decrease due to the internal resistance of the storage element 15 is eliminated, and the charge is performed again. Returning to control or discharge control can be prevented.

  As described above, according to the fifth embodiment, it is possible to suppress voltage fluctuation due to voltage fluctuation in the storage element internal resistance that occurs when the charge / discharge operation is stopped due to overcharge or voltage drop. Without causing a voltage drop, the regenerative power of the electric car 10 can be charged by the power storage element 15 and discharged by powering operation, and the regenerative power of the electric car 10 can be reused.

<< Sixth Embodiment >>
FIG. 10 and FIG. 11 are control block diagrams showing a sixth embodiment of the DC voltage feeding device according to the present invention. FIG. 10 is a control block of the discharge controller, 46 is a subtractor, 47 is an amplifier, and 48 is a limit circuit.

  The discharge control operation of FIG. 10 will be described. The subtractor 46 subtracts the terminal voltage signal Vb from the low voltage set value Level_N, and the output signal is amplified by the amplifier 47. The limit circuit 48 works to narrow the output signal when the terminal voltage signal Vb falls below the low voltage set value Level_N. Since this output signal is input as the upper limit of the limit circuit 27, the discharge current command Ib * Decreases gradually when the voltage drops below the low voltage setting.

  FIG. 11 is a control block diagram of the charge control unit. 49 is a subtracter, 50 is an amplifier, and 51 is a lower limit circuit.

  The charge control operation of FIG. 11 will be described. The subtractor 49 subtracts the terminal voltage signal Vb from the full charge set value Level_P and amplifies the output signal by the amplifier 50. The lower limit circuit 51 increases the output signal when the terminal voltage signal Vb exceeds the full charge set value Level_P. Since this output signal is input as a level in the charging operation of the charging determination circuit 33, the charging operation level at which the terminal voltage signal Vb exceeds the full charge setting value Level_P increases, and the charging current gradually decreases.

  As described above, according to the sixth embodiment, the charge / discharge current is gradually decreased with respect to the overvoltage or voltage drop of the electricity storage element 15, and the charge / discharge operation is stopped when the charge / discharge operation is stopped due to overcharge or voltage drop. Voltage fluctuation due to voltage fluctuation at the resistance can be suppressed, and the regenerative power of the electric vehicle 10 is charged by the power storage element 15 without causing an overvoltage or voltage drop in the power storage element 15, and discharged by power running operation. The regenerative power of the electric vehicle 10 can be reused.

  Note that a secondary battery such as a lithium ion battery or a nickel metal hydride battery, or a large-capacity capacitor such as an electric double layer capacitor can be applied to the storage element 15.

The circuit block diagram which shows 1st Embodiment of the DC voltage electric power feeder which concerns on this invention. The control block diagram explaining the charge / discharge switching circuit of 1st Embodiment. The control block diagram explaining the discharge control of 1st Embodiment. The control block diagram explaining charge control of a 1st embodiment. The circuit block diagram which shows 2nd Embodiment of the DC voltage electric power feeder which concerns on this invention. The control block diagram which shows 3rd Embodiment of the DC voltage electric power feeder which concerns on this invention. The circuit block diagram which shows 4th Embodiment of the DC voltage electric power feeder which concerns on this invention. The control block diagram explaining the full charge determination and low voltage determination of 4th Embodiment. The control block diagram which shows 5th Embodiment of the DC voltage electric power feeder which concerns on this invention. The control block diagram which shows 6th Embodiment of the DC voltage electric power feeder which concerns on this invention. The control block diagram which shows 6th Embodiment of the DC voltage electric power feeder which concerns on this invention. The circuit block diagram which shows an example of the conventional DC voltage electric power feeder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power source 2 ... Rectifier 3 ... DC overhead wire 4 ... Inverter 5 ... AC motor 6 ... Filter reactor 7 ... Filter capacitor 8 ... Resistor 9, 34 ... Switch 10 ... Electric car 11a, 11b ... Self-extinguishing element 12, DESCRIPTION OF SYMBOLS 33 ... Reactor 13 ... DC capacitor 14 ... Charge / discharge circuit 15 ... Power storage element 16 ... Control circuit 17, 37 ... Voltage detector 18, 19 ... Current detector 20 ... Charge control part 21 ... Discharge control part 22 ... Gate circuit 23 ... Charging / discharging determination circuit 24 ... switching circuit 25, 28, 46, 49 ... subtractor 26 ... amplifier 27, 48 ... limit circuit 29 ... current control circuit 30 ... triangular wave generation circuit 31 ... PWM circuit 32 ... charging operation determination circuit 35 ... Open / close circuit 36 ... Charging operation determination circuit with hysteresis characteristic 38 ... Full charge determination circuit 39 ... Low voltage determination circuit 40 ... Charge stop 1 ... discharge stop 42 ... charging stop switching circuit 43 ... discharge stop switching circuit 44 ... hysteresis characteristic with charging stop switching circuit 45 ... hysteresis characteristic with discharge stop switching circuit 47, 50 ... amplifier 51 ... Lower limit circuit

Claims (6)

In a DC voltage power supply device that converts an AC voltage into a DC voltage and supplies this DC voltage to an electric vehicle via a DC overhead wire,
A storage element that accumulates power supplied via the DC overhead line, a charge / discharge circuit that performs a charge / discharge operation of the storage element, a control circuit that controls the charge / discharge circuit, and an output terminal of the charge / discharge circuit A voltage detector that detects DC voltage and outputs it as a DC voltage signal to the control circuit, a current detector that detects current output to the electric vehicle and outputs it as an output current signal to the control circuit, and charge / discharge of the storage element A current detector that detects current and outputs it as a charge / discharge current signal to the control circuit,
The control circuit performs charge control of the storage element when the DC voltage signal exceeds the charge set value, and controls discharge of the storage element when the DC voltage signal exceeds the discharge set value. In the direct-current voltage electric power feeder of Claim 1,
A DC voltage power supply device comprising a switching circuit connected between a charge / discharge circuit and a DC overhead wire. In the direct-current voltage feeder according to claim 1 or 2,
Hysteresis characteristics are set for the charge setting value in the control circuit. When the DC voltage signal input to the control circuit exceeds the upper limit of the charge setting value, the storage element is controlled to be charged, while the DC voltage signal input to the control circuit The DC voltage power supply device, wherein the charging control of the storage element is stopped when the battery voltage falls below a lower limit of the charge set value. In the DC voltage electric power feeder of any one of Claims 1-3,
A voltage detector that detects a storage element voltage and outputs a storage element voltage signal to the control circuit;
The control circuit stops the charging operation when the input storage element terminal voltage exceeds the full charge set value, and stops the discharge operation when the input storage element terminal voltage falls below the low voltage set value. A DC voltage power supply device. In the direct-current voltage electric power feeder of Claim 4,
A DC voltage power supply apparatus, wherein a hysteresis characteristic is set for each of a full charge set value and a low voltage set value in a control circuit. In the DC voltage electric power feeder of any one of Claims 1-3,
A voltage detector that detects a storage element voltage and outputs a storage element voltage signal to the control circuit;
The control circuit gradually suppresses the charging current when the input storage element terminal voltage exceeds the full charge setting value, and gradually reduces the discharge current when the input storage element terminal voltage falls below the low voltage setting voltage. A DC voltage power supply device characterized by being suppressed.

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