Method and a system for monitoring and regulating the power consumed by a transport system

• US 7,397,149 B2
• Filed: 04/18/2003
• Issued: 07/08/2008
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Alstom SA
• Original Assignee: Alstom SA
• Inventors: Seddiki, Rachid, Cornic, Daniel
• Primary Examiner(s): Sherry; Michael J
• Assistant Examiner(s): CAVALLARI, DANIEL J
• Application Number:
  US10/418,100
• Publication Number:
  US 20030230994A1
• Time in Patent Office: 1,908 Days
• Field of Search: 307/62, 246/5, 105/49
• US Class Current: 307/62
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2072 for drive off
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 9/00 Electric propulsion with power supply external to the vehicle electric propulsion for monorail vehicles, suspension vehicles or rack railways B60L13/00; in combination with batteries or fuel cells within the vehicle B60L50/53
• CPC Class Codes: B60M 3/00 Feeding power to supply lines in contact with collector on vehicles; Arrangements for consuming regenerative power controlling rail vehicles by varying voltage of power fed to vehicle B60L; power distribution in general H02J
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A method of monitoring and regulating the power and the energy consumed by a transport system including electrically propelled vehicles, said transport system including a power supply system including one or more power supply substations connected to an external electrical power supply network, said power supply substation or substations supplying energy to traction substations supplying power to power supply line sections having vehicle-mounted current pick-up means connected thereto, each vehicle carrying a power converter which is supplied with power by said current pick-up means and which monitors the power supplied to a traction motor of said vehicle, which method includes the following steps:

• • measuring the instantaneous electrical power and/or energy drawn from the external electrical power supply network by said power supply substation or substations, and
  • if the power or energy drawn from the external network tends to exceed an assigned threshold, sending one or more vehicles a set point acting on the converter on board said vehicle to reduce temporarily the power and/or the speed of rotation of the traction motor.

Claims

1. A method or monitoring and regulating power and energy consumed by a transport system comprising electrically propelled vehicles and a power supply system comprising one or more power supply substations connected to an external electrical power supply network, the method comprising:

measuring instantaneous at least one of electrical power and energy drawn from the external electrical power supply network by said power supply substation or substations; and

if the power or energy drawn from the external network exceeds an assigned threshold, sending one or more vehicles a set point acting on a converter on board of said vehicle temporarily reducing at least one of the power and speed of rotation of a traction motor of said vehicle,

wherein said vehicles move in accordance with a control profile, said control profile comprising starting the vehicle with a constant traction force which is applied until a maximum power is consumed by the vehicle, subsequent acceleration of the vehicle up to a maximum speed conforming to an equal power equation comprising traction force of the vehicle times speed of the vehicle is to remain constant.

2. A method according to claim 1, wherein said vehicles move in accordance with the control profile, said control profile comprising starting of the vehicles with the constant traction force which is applied until a line current I_A flows in the onboard converter, wherein the value of the line current I_A depends on the nominal operating current of the traction motor or to a lower value modulated as a function of the load of the vehicle, wherein subsequent acceleration of the vehicle up to the maximum speed is conforming to the equal power equation.

3. A method according to claim 1, wherein said vehicles move in accordance with a control profile whereby starting is effected in compliance with an equation specifying how speed is increased up to an authorized maximum speed.

4. A method according to claim 2, wherein the set point sent to the vehicle is a reduction set point α

for limiting the line current I_A to a value I_L=α

.I_A.

5. A method according to claim 1, wherein the set point sent to the vehicle is a reduction set point β

for the maximum speed provided by the converter on board said vehicle to the motor, wherein said set point β

is provided to the converter on board the vehicle to limit the speed of rotation of the traction motor.

6. A method according to claim 4, wherein vehicles receiving at least one of set points α

and set points β

is selected from vehicles of the transport system as a function of a critical status index V_C assigned to each vehicle and a critical status index Z_C assigned to each power supply line section.

7. A method according to claim 6, wherein:

the power supply substation or substations supply energy to traction substation supplying power to the power supply line sections having vehicle-mounted current pick-up means connected thereto,

each vehicle carrying the power converter which is supplied with power by said current pick-up means and which monitors at least one of the power and the speed of rotation of the traction motor of said vehicle, and

the critical status index V_C assigned to each vehicle is based on at least one of late running of the vehicle, the time interval between successive vehicles, and the load of the vehicle, and wherein the critical status index Z_C assigned to each power supply line section allows for at least one of the status of the traction substations and the power supply substation supplying power to said section, and geometry of a route followed by the vehicles in the line section.

8. A method according to claim 4, wherein at least one of reduction set points α

and reduction set points β

received by each of vehicles is modulated as a function of the critical status index V_C assigned to respective vehicle.

9. A method according to claim 8, wherein the value of said set point α

is from 70% to 100%, as a function of the critical status index V_C of the respective vehicle.

10. A method according to claim 8, wherein the value of said set point β

is from 60% to 100%, as a function of the critical status index V_C of the respective vehicle.

11. A method according to claim 1, wherein, if said transport system comprises significant infrastructure auxiliary systems supplied with electrical power by a power supply substation, as well as sending set points to vehicles, the set points are sent for reducing the operating regime of the less critical infrastructure auxiliary systems.

12. A method according to claim 1 for monitoring and regulating the power consumed by a transport system, wherein the value of at least one of said assigned power and energy threshold is a function respectively of predetermined power and energy maximums set by the external electrical power supplier, said thresholds being adaptable as a function of the time or the season.

13. A method according to claim 12, wherein said power and energy thresholds are temporarily assigned values below the nominal power and energy values set by the external electrical power supplier.

14. A method according to claim 3 for monitoring and regulating the power consumed by a transport system, wherein the method further comprises:

measuring electrical parameters supplied by traction substations that supply power to power supply line sections having vehicle-mounted current pick-up means connected thereto; and

selecting vehicles to which at least one of set points α and

set points β

are sent based on results of the measuring of the electrical parameters,

wherein each vehicle carries a power converter which is supplied with power by said current pick-up means and which monitors the power and/or the speed of rotation of the traction motor of said vehicle, and

wherein the power supply substation or substations supply energy to the traction substations.

18. The method according to claim 11, wherein the less critical infrastructure auxiliary systems comprises at least one of a ventilation system, an air conditioning system, and a lighting system of stations.

20. The method according to claim 1, wherein the measuring of at least one of the electrical power and energy drawn from the external electrical power supply network comprises measuring active power, reactive power, and wattage drawn from the external source and billing the transport system based on results of said measuring.

21. The method according to claim 1, wherein the transport system comprises a plurality of power supply substations, wherein each power supply substation measures at least one of the electrical power and energy drawn from the external electrical power supply network and sends results of the measurement to a control station, and wherein the control station computes at least one of total electrical power and energy drawn from the external electrical power supply network.

22. The method according to claim 21, wherein the plurality of substations comprise a first type of substation supplying power or energy to respective traction substations that supply power or energy to the vehicles and a second type of substation supplying power or energy to auxiliary systems of the transport system.

23. The method according to claim 1, wherein, if the power or energy drawn from the external network exceeds the assigned threshold, sending at least one vehicle the set point acting on the converter on board of respective vehicle, wherein the sent set point acts on the converter such that the maximum line current power that is supplied to the onboard converter of said respective vehicle is reduced.

24. The method according to claim 1, wherein, if the power or energy drawn from the external network exceeds the assigned threshold, sending at least one vehicle the set point acting on the converter on board of respective vehicle, wherein the set points act on the converter such that the speed of rotation of the traction motor of said respective vehicle is temporarily reduced, wherein the speed of rotation of the traction motor is a maximum speed of rotation assigned to the traction motor of the respective vehicle.

15. A system for monitoring and regulating the power and the energy consumed by a transport system comprising a plurality of vehicles having an electric traction motor and a power supply substation connected to an external electrical power supply network, the system comprises:

a measurer measuring and metering the electrical power drawn from the external electrical power supply network by the power supply substation;

a detector detecting times at which at least one of the power and the energy drawn from the external network exceeds an assigned threshold; and

a transmitter sending at least one set point to at least one vehicle if the power or the energy drawn from the external network exceeds said threshold, said set points provided to a converter on board said vehicle temporarily reducing the at least one of power and the speed of rotation of the traction motor of said vehicle,

wherein said vehicles move in accordance with a control profile whereby the vehicles are started in compliance with a constant traction force which is applied until a maximum power is consumed by the vehicle, and wherein subsequent acceleration of the vehicles are up to a maximum speed conforming to an equal power equation comprising traction force of the vehicle times speed of the vehicle is to remain constant.

16. A system according to claim 15 for monitoring and regulating the power consumed by a transport system, wherein said set points sent to the vehicle are at least one of current reduction set points α

and speed reduction set points β

, said set point α

provided to the converter on board said vehicle limits the line current to below the limit current I_A, and said set point β

provided to the converter on board limits the speed of rotation of the traction motor.

17. A power monitoring and regulating system according to claim 15, wherein the set points are sent to the vehicles from a centralized control station by means of a radio transmission system or, in a station, by an infrared transmission system.

19. The system according to claim 15, wherein the power supply substation or substations supply energy to traction substations supplying power to power supply line sections having vehicle-mounted current pick-up means connected thereto and wherein each vehicle carrying a power converter is supplied with power by said current pick-up means and monitors at least one of the power and the speed of rotation of the traction motor of said vehicle.