JP2018033212A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause an excitation current to flow through an induction machine even if a main circuit has no power source, and to secure regenerative operation.SOLUTION: An electric vehicle comprises: a main transformer 22 in which a pantograph 12 obtaining an AC is connected to a primary winding 22a via a circuit breaker 21; a single-phase converter 24 being connected to a first secondary winding 22b and converting the AC into a DC; a three-phase inverter 28 converting an output DC into the AC; a filter capacitor 26 disposed between two lines of a DC link part 25 between the single-phase converter 24 and the three-phase inverter 28; an induction machine 29 driven by the AC from the three-phase inverter 28; auxiliary equipment 32 in the vehicle; a sub power conversion device 31 being connected to a second secondary winding 22c of the main transformer 22 and supplying power to the auxiliary equipment 32; an in-vehicle control part 47 being annexed with a low voltage storage battery 46 and performing ON/OFF control of the auxiliary equipment 32; and a regenerative excitation circuit 41 connecting the low voltage storage battery 46 to the DC link part 25 in a state of disconnecting the pantograph 12 and the main transformer 22 by the circuit breaker 21 and performing initial excitation of the induction machine 29 by power supply from the low voltage storage battery 46. After the initial excitation, the induction machine 29 is subjected to regenerative operation.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to an electric vehicle.

  Conventionally, in an electric locomotive that pulls or propels a passenger car or a freight car, a main power conversion device that supplies electric power to an electric motor for driving the electric locomotive, as well as an air conditioner mounted on the passenger car or the freight car, etc. An auxiliary power converter (APU) that supplies power to the auxiliary equipment is installed.

  As a railway vehicle system using this type of APU, for example, a technique for suppressing an excitation inrush current to the main transformer at the time of obtaining power from an overhead line has been proposed. (For example, Patent Document 1)

JP 2010-2115013 A

  In an overhead line that supplies power to an electric locomotive via a current collector such as a pantograph, in order to smoothly transfer the electric locomotive between overhead lines belonging to different power supply systems, power is transferred between the overhead lines belonging to different electrical systems. A section called a dead section that is a non-powered section that is not supplied is provided.

  When passing through this dead section, the power supply to the current collector is temporarily stopped, so that no power is supplied to the APU.

  In addition to the dead section above, there are places where there are no overhead lines for the purpose of simplifying equipment etc. in the depot, and it is necessary to lower the pantograph for safety reasons in the case of forwarding vehicles. With the circuit breaker open, the power from the overhead line cannot be used by the APU.

  On the other hand, for example, a method of supplying power to the APU by performing regeneration in a dead section has been proposed.

  In an electric locomotive that uses an induction motor (hereinafter referred to as an “induction machine”) as an electric motor, it is essential that an induction current flows even during regeneration, based on the principle that an induction motor generates magnetic flux by flowing an excitation current. Become.

  However, in a state where power cannot be supplied to the main circuit of the vehicle as in the above-described dead section, it is not possible to flow an exciting current, and as a result, regeneration cannot be performed.

  On the other hand, since there is always a low-voltage battery (DC 110 [V]) for the control power supply in the vehicle, it is considered to secure an exciting current even during regeneration of the induction motor by using this low-voltage battery. It is done.

  However, since the main circuit is a DC 3000 [V] class high voltage circuit, the low voltage power supply is extremely different from the 100 [V] class, and naturally the insulation level is also different. If high pressure is applied to the side, it will lead to equipment destruction.

  In addition, grounding is another concern. Normally, the high-voltage main circuit grounds the neutral point of the main circuit in order to suppress insulation from the ground including the rail. On the other hand, the negative side of the low voltage side circuit is grounded. Therefore, by connecting the low-voltage side circuit as it is between the lines of the high-voltage main circuit, the insulation of the main circuit with respect to the ground may be increased for normal use. If this is repeated, there is a risk that the equipment will be destroyed due to insulation breakdown of the main circuit.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to secure an electric power for an auxiliary machine by regeneration by supplying an excitation current to the induction motor even when there is no power source in the main circuit. A further object is to provide an electric vehicle capable of ensuring insulation between the line withstand voltage on the low voltage circuit side and the installation point on the main circuit circuit side.

  The electric vehicle of the embodiment is connected to a primary transformer connected to a primary winding via a circuit breaker, and a current collector that obtains alternating current from an overhead wire, and to the first secondary winding of the main transformer, A single-phase converter that converts alternating current from an overhead wire into direct current, an inverter that converts direct current output from the single-phase converter into alternating current, and a direct current connection between the single-phase converter and the inverter. A filter capacitor, an induction motor driven by the alternating current output from the inverter, an auxiliary machine provided in the vehicle, and a second secondary winding of the main transformer are connected via the main transformer. A sub-power converter that supplies electric power to the auxiliary machine by alternating current, an in-vehicle controller that includes a low-voltage storage battery that controls the operation of the auxiliary machine, and the primary winding of the current collector and the main transformer. Disconnect the wire with the above circuit breaker In the state, the low-voltage storage battery is connected to the DC connection portion, and the induction motor is initially excited by at least one of power supply from the low-voltage storage battery and power supply from the filter capacitor that stores the power of the low-voltage storage battery. And regenerative control means for regenerating the induction motor initially excited by the regenerative excitation means.

The figure which illustrates the relationship between the train and overhead line which concern on one Embodiment. The block diagram which shows the circuit structure of the vehicle control apparatus which concerns on the same embodiment. The flowchart which shows the processing content mainly at the time of a dead section passage of the vehicle control apparatus which concerns on the embodiment. The figure which illustrates the signal waveform in each circuit of FIG. 2 concerning the embodiment.

Hereinafter, an embodiment will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating a relationship between a train 100 and an overhead line 11 according to an embodiment. In the figure, a train 100 is configured by connecting an electric locomotive (railway vehicle) 101 and a passenger car (or freight car) 102 towed (or propelled from behind) by the electric locomotive 101.

  Here, the electric locomotive 101 includes a pantograph 12 that collects AC power from an overhead wire (wire) 11 and a wheel 14 that is installed via a track 13.

  On the track 13, a ground element ET is laid at an appropriate location, and information transmitted from the ground element ET when passing over the ground element ET is detected by the vehicle element TT provided in the electric locomotive 101, It can be used by the vehicle control device 16. The vehicle control device 16 is provided, for example, in the cab of the electric locomotive 101, and operates according to a preset operation program with a built-in computer.

  The overhead line 11 includes two overhead lines 11A and 11B having different power supply systems, and a non-electric section 11X that is an intermediate section disposed between the overhead lines 11A and 11B. The non-electric section 11X is also referred to as a dead section or a dead-electric section, and the train 100 travels in a coasting manner in the non-electric section 11X at a preset vehicle speed or higher.

  FIG. 2 shows a partial circuit configuration in the vehicle control device 16 of the electric locomotive 101. In this figure, a primary circuit 22a of a vacuum circuit breaker (VCB) 21 and a main transformer 22 is connected in series between a pantograph 12 and a wheel 14 installed via a track 13. A single-phase converter 24 is connected to the secondary winding 22 b of the main transformer 22 via a main circuit contactor (K 1) 23.

  For example, AC power of 25 [kV] and 50 [Hz] supplied through the pantograph 12 is transformed by the main transformer 22 and taken out as AC power of 1000 [V], and the single-phase converter 24 takes, for example, After being converted to DC power of 2800 [V], it is converted to three-phase AC by a three-phase inverter 28 via a neutral point ground (NG) circuit 30 and a DC link unit 25 to drive the induction machine 29. .

  The neutral point ground (NG) circuit 30 includes, for example, two resistors (r) that connect between the lines, and a capacitor that connects the midpoint of these resistors and a minus line, and grounds the midpoint. It has become.

  The induction machine 29 is regeneratively driven as a generator during coasting and is used as a power source for obtaining regenerative power.

  The DC link unit 25 is provided with a capacitor 26 and an overvoltage input protection (OVT) circuit 27. The overvoltage input protection circuit 27 is a circuit in which a resistor (r) and a contactor switch are connected in series, and functions as a discharge circuit that discharges the charge accumulated in the capacitor 26 as heat by a resistor.

  The DC link voltage Vdc applied across the capacitor 26 is detected by the voltage sensor VS and sent to the DC link voltage control unit (AVR) 33.

  A DC link voltage command value VdcRef is input to the DC link voltage control unit 33, and a Q-axis current command value IqRef corresponding to the difference is generated and supplied to the subtractor 34. An actual current value Iq, which will be described later, is given to the subtractor 34 as a subtraction, and the difference output is sent to the current control unit 37.

  On the other hand, an angular frequency FR indicating the speed of the induction machine 29 is given to the excitation current command calculation unit 35. The excitation current command calculation unit 35 generates a command value IdRef of the excitation current for the D axis from the angular frequency FR and supplies it to the subtractor 36. An actual current value Id, which will be described later, is given as a subtraction to the subtracter 36, and the difference output is sent to the current control unit 37.

  The current control unit 37 calculates a current command value from the difference output of both the subtractors 34 and 36, converts it into a three-phase current command by the DQ / 3-phase conversion unit 38, and further modulates the pulse width by the PWM unit 39. Then, it is given to the three-phase inverter 28 as a gate control signal.

The currents Iu, Iw in the currents Iu, Iv, Iw that are actually output from the three-phase inverter 28 to the induction machine 29 are detected by the current sensors ISu, ISw, and the actual current values Id, Iq are detected by the three-phase / DQ converter 40. And is given as a reduction to the subtracters 36 and 34 for feedback control.
The DC link voltage controller 33, the subtractor 34, the excitation current command calculator 35, the subtractor 36, the current controller 37, the DQ / 3 phase converter 38, the PWM unit 39, and the 3 phase / DQ converter 40. The feedback control circuit configuration itself is the same as that based on general PI control, and a detailed description of the operation is omitted.

  Further, an auxiliary power converter (APU: Auxiliary Power Unit) 31 is connected to the second secondary winding 22 c of the main transformer 22. Although only one system is illustrated in the figure, the sub power converter 31 is a power circuit in which a rectifier, an auxiliary transformer, and a voltage regulator are integrated, and is provided in units of trains 100. Thus, AC power supplied from the main transformer 22 is supplied to the auxiliary machine 32 according to various auxiliary machines 32 provided in the vehicle, such as an air conditioner, a blower, an air compressor, a door closing device, a lighting device, etc. In total, in the range of about 100 [V] to 440 [V], for example, it is converted into electric power of three-phase AC 440 [V] and supplied to the corresponding auxiliary machine 32.

  On the other hand, an in-vehicle control unit 47 is provided that controls all the auxiliary machines 32 of the vehicle control device 16 and controls their on / off as necessary. The in-vehicle control unit 47 operates with a DC constant voltage supplied from the sub power device 31, for example, 110 [V]. The in-vehicle control unit 47 is connected to a low-voltage storage battery 46 so as to be uninterrupted power supply so that the circuit is not interrupted even in the event of a power failure or accident, and is connected to the DC link unit 25 via a regenerative excitation circuit 41. Connected.

  The regenerative excitation circuit 41 is arranged on the side of the storage battery switching contactor (K2) 42 for supplying the power of the low-voltage storage battery 46 to the DC link unit 25, and the in-vehicle control unit 47 side of the storage battery switching contactor 42. The backflow prevention diodes 43 and 44 and a resistance (r) 45 connected in series to the anode side of the backflow prevention diode 43 are provided.

  As the backflow prevention diodes 43 and 44, those having a sufficiently high breakdown voltage are used in order to prevent a high-voltage DC voltage from the main circuit from being applied to the in-vehicle controller 47 side via the DC link unit 25. The resistor 45 is installed to prevent the inrush current from flowing into the in-vehicle control unit 47.

  Here, when only the backflow prevention diode 43 is provided and the backflow prevention diode 44 is not provided, in the figure of the storage battery switching contactor (K2) 42, when only the lower neutral side is stuck, In the figure of the main circuit, the ground potential on the upper plus side corresponds to the DC link voltage.

  Usually, since the main circuit is grounded at a neutral point, there is a possibility that the withstand voltage of the backflow prevention diode 43 may be exceeded. However, the backflow prevention diode 44 is also provided on the ground side of the in-vehicle control unit 47 on the neutral side. Thus, it is possible to reliably avoid a situation that exceeds the withstand voltage of the main circuit device.

  Further, when the storage battery switching contactor 42 is closed due to a high voltage, the DC link unit 25 conducts a switch in the overvoltage input protection circuit 27 so that the charge charged in the capacitor 26 of the DC link unit 25 is overvoltage. It is assumed that heat is released by the resistance in the input protection circuit 27.

  Although not shown, there are a current sensor for detecting the current flowing through the first secondary winding 22b of the main transformer 22 and a current sensor for detecting the current flowing through the second secondary winding 22c. Each shall be provided.

Next, the operation of the above embodiment will be described.
FIG. 3 is a part of the contents of an operation process executed by a computer (not shown) built in the vehicle control device 16 of the electric locomotive 101, and in particular, the process contents before and after passing through the non-electric section 11X of the overhead wire 11. Is extracted and shown.

  At the beginning of the processing, the vehicle control device 16 determines whether the signal from the ground element ET provided on the track 13 at a certain distance before the non-electric section 11X can be detected by the on-board element TT. Is repeatedly determined (step S101), and it waits to reach the non-electric section 11X.

  When it is determined that the signal from the ground element ET provided in front of the non-electric section 11X can be detected by the on-board element TT and is in front of the non-electric section 11X (Yes in step S101), the vehicle control device 16 then Then, by comparing the value of the DC link voltage Vdc in the DC link unit 25 with a preset threshold value, it is determined whether or not there is an amount of charge in the capacitor 26 so that it is not necessary to perform the subsequent regenerative operation (step S102). ).

  Here, when it is determined that the value of the DC link voltage Vdc is higher than the threshold value and the capacitor 26 has sufficient charge (Yes in step S102), the vehicle control device 16 performs processing for the regenerative operation described below. The auxiliary power 32 is operated by the auxiliary power conversion device 31 using the electric charge charged in the capacitor 26.

  If it is determined in step S102 that the value of the DC link voltage Vdc is equal to or less than the threshold value and the electric charge charged in the capacitor 26 is not sufficient (No in step S102), the vehicle control device 16 next performs no power It is determined whether or not the setting for supplying power to the auxiliary machines by the regenerative operation in the section 11X has been made at the time of starting the operation in advance (step S103).

  If it is determined that the same setting is made (Yes in step S103), the vehicle control device 16 next determines whether or not the condition at the start of the regenerative operation is upright (step S104).

Here, the conditions at the start of the regenerative operation are the following four:
Turning off the vacuum circuit breaker 21 connected to the primary winding 22a of the main transformer 22 and confirming its state;
Turning off the main circuit contactor (K1) 23 connected to the first secondary winding 22b of the main transformer 22 and confirming its state;
The vehicle speed of the electric locomotive 101 is equal to or higher than the minimum speed set for the passage of the non-electric section 11X, and is equal to or higher than a predetermined speed at which auxiliary equipment can be fed by regenerative power; and
The DC link voltage Vdc is equal to or lower than a predetermined value a1 (eg, 115 [V]) within the allowable voltage range (eg, 120 [V]) of the low-voltage storage battery 46;
It is.

  When it is determined in step S103 that the power supply to the auxiliary equipment is not set by the regenerative operation in the non-electric section 11X (No in step S103), and in step S104, the condition at the start of the regenerative operation is When it is determined that any one is not upright (No in step S104), the vehicle control device 16 assumes that power is not supplied to the auxiliary machine 32 by the regenerative operation in the non-electric section 11X. End the process.

  If it is determined in step S104 that all of the above conditions for starting the regenerative operation are satisfied (Yes in step S104), the vehicle control device 16 renews the storage battery switching contactor (K2) of the regenerative excitation circuit 41. 42 is turned on, the low voltage power of the low voltage storage battery 46 is supplied to the DC link unit 25, and the initial excitation of the induction machine 29 is started via the three-phase inverter 28 (step S105).

  Further, the vehicle control device 16 starts the gate control to the three-phase inverter 28, and at the same time, the excitation current command calculation unit 35 causes the excitation current command value IdRef to be a constant value, for example, 30 [A] by the angular frequency FR of the induction machine 29. (Step S106). In this case, the initial torque current command is “0 (zero)”.

  Thereafter, the vehicle control device 16 waits for a predetermined time that has been set in advance according to the time constant characteristic of this circuit (step S107).

  The standby operation for the predetermined time is not limited to management by time, but may be determined by monitoring the DC link voltage Vdc and determining the value. However, since the circuit responds to the time constant, the management by time has the advantage that the control process can be omitted and the processing in the vehicle control device 16 can be simplified. .

  When it is determined that the predetermined time has elapsed (Yes in step S107), the vehicle control device 16 starts control based on the DC link voltage Vdc (step S108).

  The DC link voltage command value VdcRef given to the DC link voltage control unit 33 at the beginning of this voltage control is the DC link voltage Vdc at that time. Thereafter, the DC link voltage command value VdcRef is gradually increased to a maximum voltage, for example, Gate control is performed by the three-phase inverter 28 so as to increase the voltage to 2800 [V].

  Thereafter, it waits for the DC link voltage Vdc to rise until the DC link voltage Vdc becomes equal to or higher than the predetermined value a1 (step S109).

  Here, the standby until the DC link voltage Vdc becomes equal to or higher than the predetermined value a1 is a circuit for supplying an exciting current until the regenerative torque is actually applied when the storage battery switching contactor (K2) 42 is subsequently turned off. In consideration of the possibility that the DC link voltage Vdc temporarily decreases due to loss in the battery, a relatively high predetermined value a1 within the allowable voltage range of the low-voltage storage battery 46 is used as a control threshold value. .

  When it is determined that the DC link voltage Vdc is equal to or higher than the predetermined value a1 (Yes in step S109), the vehicle control device 16 is in a state where the DC link voltage Vdc is within the allowable voltage range of the low voltage storage battery 46. The storage battery switching contactor (K2) 42 is turned off to protect the low voltage side circuit from being affected by the high voltage from the main circuit (step S110).

  Here, the vehicle control device 16 checks whether or not the storage battery switching contactor 42 is turned on due to whether or not the storage battery switching contactor (K2) 42 is turned off by the above processing. (Step S111).

  If it is determined that the battery switch contactor 42 is stuck and turned on (Yes in step S111), the vehicle control device 16 uses the backflow prevention diodes 43 and 44 to control the in-vehicle control power supply 47. However, in order to cope with the subsequent application of a high voltage from the main circuit, the DC link unit 25 is discharged by turning on the overvoltage input protection circuit 27 as described above. The regenerative operation is interrupted, and the process proceeds to a recovery process for the regenerative excitation circuit 41 including the storage battery switching contactor 42.

  In step S111, if it is confirmed that the storage battery switching contactor 42 is not turned on and is turned off (No in step S111), the vehicle control device 16 then sets it higher than the predetermined value a1. It waits for the DC link voltage Vdc to rise until it reaches the predetermined value a2 (step S113).

  The predetermined value a2 is a value set to confirm that the DC link voltage Vdc has risen beyond the allowable voltage range of the low voltage storage battery 46, and is relatively higher than the allowable voltage range of the low voltage storage battery 46. A value that can be determined at an early timing is selected in advance.

  When it is determined that the DC link voltage Vdc is equal to or higher than the predetermined value a2 (Yes in step S113), the vehicle control device 16 starts the sequence control of the regenerative operation, and thereafter the electric power generated in the induction machine 29. Is supplied to the auxiliary machine 32 (step S114).

  While the storage battery switching contactor 42 is turned on, the negative side of the main circuit is at 0 (zero) potential. When the storage battery switching contactor 42 is turned off as described above, the ground potential changes due to the time constant response by the resistance and capacitor of the neutral point ground circuit 30 of the main circuit, and the normal potential state, that is, the DC link portion 25 of the main circuit. The intermediate point of is a 0 (zero) potential.

  If the regenerative torque current is applied to increase the DC link voltage Vdc of the main circuit to the rated current faster than the time constant response of the neutral point grounding circuit 30, the ground potential of the main circuit portion becomes the normal ground potential. There is a possibility of exceeding.

  For this reason, if the DC link voltage Vdc is gradually increased so as to be slower than the time constant response of the neutral point grounding circuit 30, it is possible to avoid device breakdown due to insulation breakdown on the main circuit side.

  While executing the above-described power supply sequence to the auxiliary machine 32 by the regenerative operation, the vehicle control device 16 waits for the end of the non-electric section 11X as the electric locomotive 101 proceeds (step S115).

  This is determined based on whether or not the signal from the ground child ET installed at a predetermined position at the end in the non-electric section 11X can be detected by the on-board element TT, and until the end of the non-electric section 11X is reached. Maintain the power supply sequence for regenerative operation.

  In step S115, when it is determined that the signal from the ground child ET installed at the predetermined position at the end in the non-electric section 11X can be detected by the on-board child TT, it is determined that the end of the non-electric section 11X is reached (Yes in step S115). ), The vehicle control device 16 cancels the power supply sequence to the auxiliary machinery by the above regenerative operation, and completes the processing of FIG. 3 to prepare for the operation from the section of the next overhead wire 11B.

  FIG. 4 is a diagram illustrating signal waveforms at each circuit position in the vehicle control device 16 at the beginning of the regenerative operation. 4A to 4D, the horizontal axis indicates the elapsed time (unit [second]) from the timing when the storage battery switching contactor (K2) 42 is turned on in step S105.

  At timing t11, the gate control of the three-phase inverter 28 is started by the processing in step S106, and the command value is raised so that the excitation current Id becomes constant at, for example, 30 [A].

  Further, at the timing t12, the control of the DC link voltage Vdc is started by the processing in step S108, and the excitation current command IdRef is given to the control system.

  FIG. 4F shows the current of the low voltage storage battery 46. As shown in the figure surrounded by a mark IV, 0... Immediately after the storage battery switching contactor (K2) 42 is turned on. Current flows through the low-voltage storage battery 46 for several seconds.

  FIG. 4A shows changes in the DC link voltage Vdc. Immediately after turning on the storage battery switching contactor (K2) 42, the supply voltage 110 [V] of the storage battery switching contactor 42 is maintained, and thereafter voltage control is started at the timing t12 until the maximum voltage 2800 [V]. It can be seen that it gradually increases over about 3 [seconds].

  FIG. 4B shows a state in which the excitation current Id is controlled at a constant value, for example, 30 [A] from the timing t11.

  On the other hand, FIG. 4C shows the control result of the Q-axis current Iq based on the output control of the DC link voltage Vdc. After the timing t12, it can be seen that the current is displaced with a negative current value due to the regenerative operation.

  FIG. 4D shows angular frequency commands FR indicating the speed of the induction machine 29 indicated by broken lines, and the output frequency F1 of the three-phase inverter 28 indicated by solid lines. As the negative torque appears in response to the regenerative operation, the slip frequency F1 is negative.

  FIG. 4E shows the amplitudes of currents Iu, Iv, and Iw of three phases (U phase, V phase, and W phase). 4A shows a state in which the amplitude is increased or decreased in all three phases in accordance with the DC link voltage Vdc in FIG. 4A and the DC voltage control in FIG. 4B.

  As described above in detail, according to the present embodiment, even when power is not supplied to the main circuit as in the non-electric section 11X, for example, the induction machine 29 is initially excited with the power of the low-voltage storage battery 46 that is a constant pressure power source. It is possible to secure electric power for auxiliary equipment by regeneration by supplying current, and to ensure insulation between the line withstand voltage on the low voltage circuit side and the installation point on the main circuit circuit side.

  In the above embodiment, the erecting of the preset condition is confirmed before the regenerative operation is started, and the regenerative operation is surely started to secure the power for the auxiliary machine.

  In addition, in the above embodiment, after confirming that the regenerative operation is started reliably, the storage battery switching contactor (K2) 42 is connected before the DC link voltage Vdc actually increases with the regenerative operation. In other words, the circuit on the low voltage side is protected without depending on the backflow prevention diodes 43 and 44, and the circuits on the low voltage side can be reliably protected in combination with the presence of the backflow prevention diodes 43 and 44.

  Furthermore, when the battery switch contactor (K2) 42 is stuck, the overvoltage input protection (OVT) circuit 27 is used to discharge the DC link unit 25 in conjunction with it. Each circuit can be protected.

  Although the embodiment has been described above, the embodiment is presented as an example, and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 11, 11A, 11B ... Overhead wire, 11X ... No electric section, 12 ... Pantograph, 13 ... Track, 14 ... Wheel, 16 ... Vehicle control device, 21 ... Vacuum circuit breaker (VCB), 22 ... Main transformer, 22a ... Primary volume Wire, 22b ... first secondary winding, 22c ... second secondary winding, 23 ... main circuit contactor (K1), 24 ... single phase converter, 25 ... DC link section, 26 ... capacitor, 27 ... Overvoltage input protection (OVT) circuit, 28 ... 3-phase inverter, 29 ... induction motor, 30 ... neutral point ground (NG) circuit, 31 ... auxiliary power converter (APU), 32 ... auxiliary machine, 33 ... DC link voltage Control part (AVR) 34 ... Subtractor 35 ... Excitation current command calculation part 36 ... Subtractor 37 ... Current control part (ACR) 38 ... DQ / 3 phase conversion part 39 ... PWM part 40 ... 3 Phase / DQ conversion unit, 41 ... regenerative excitation circuit, 42 Storage battery switching contactor (K2), 43, 44 ... Backflow prevention diode, 45 ... Resistance, 46 ... Low voltage storage battery, 47 ... In-vehicle control unit, 100 ... Train, 101 ... Electric locomotive, 102 ... Passenger car, ET ... Ground element, TT ... A car upper child.

Claims (8)

A main transformer in which a current collector for obtaining alternating current from an overhead wire is connected to a primary winding via a circuit breaker;
A single-phase converter connected to the first secondary winding of the main transformer for converting alternating current from the overhead wire into direct current;
An inverter that converts direct current output from the single-phase converter into alternating current;
A filter capacitor connected between two wires of a DC connection between the single-phase converter and the inverter;
An induction motor driven by alternating current output from the inverter;
An auxiliary machine installed in the vehicle;
A sub-power converter connected to the second secondary winding of the main transformer and supplying power to the auxiliary machine by an alternating current supplied via the main transformer;
In-vehicle control unit with a low-voltage storage battery for controlling the operation of the auxiliary machine,
In a state where the primary winding of the current collector and the main transformer is cut off by the circuit breaker, the low voltage storage battery is connected to the DC connection portion, and the power supply from the low voltage storage battery and the power of the low voltage storage battery Regenerative excitation means for initial excitation of the induction motor by at least one of power supply from the filter capacitor
An electric vehicle comprising: a regeneration control means for causing the induction motor that is initially excited by the regeneration excitation means to perform a regeneration operation. The regenerative excitation means has a contactor that intermittently connects between the low-voltage storage battery and the DC connection part,
On condition that the circuit breaker is open, the DC connection is not more than a predetermined voltage value corresponding to the low voltage storage battery, and the traveling speed of the vehicle is not less than a preset speed. The electric vehicle according to claim 1, wherein the contactor is in a connected state.   At least when a predetermined time has elapsed since the contactor was connected, before the regenerative current from the induction motor flows by the regenerative control means, and when the voltage at the DC connection becomes a preset voltage. The electric vehicle according to claim 2, wherein the contactor is in a disconnected state on the condition of one.   2. The electric vehicle according to claim 1, further comprising a diode connected between the DC connection portion and the low-voltage storage battery in a direction of blocking current flowing from the DC connection portion to the low-voltage storage battery.   The electric vehicle according to claim 4, wherein the diode has a withstand voltage characteristic higher than a maximum voltage applied to the DC connection portion.   6. The electric vehicle according to claim 4, wherein the diode is provided on both of the two lines connecting the DC connection portion and the low-voltage storage battery. A judging means for judging a signal for judging a case where a firmness occurs in the contactor;
3. The electric motor according to claim 2, further comprising: a discharge circuit that discharges a charge at a DC connection portion between the single-phase converter and the inverter when the determination means determines whether the regenerative excitation means is firm. vehicle. The DC connection part further includes a neutral point grounding circuit for grounding at the neutral point of the DC voltage,
2. The electric vehicle according to claim 1, wherein the regeneration control means limits a voltage change speed when the induction motor is regenerated based on a time constant characteristic of the neutral point grounding circuit.