DRIVE SYSTEM FOR ELECTRICALLY DRIVEN DUMP TRUCK

• US 20090132116A1
• Filed: 05/18/2007
• Published: 05/21/2009
• Est. Priority Date: 06/06/2006
• Status: Abandoned Application

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Yasuda, Tomohiko, Tanaka, Yasuo, Watanabe, Yutaka, Yagyu, Takashi
• Application Number:
  US12/097,053
• Publication Number:
  US 20090132116A1
• Time in Patent Office: Days
• US Class Current: 701/36
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2300/125 Heavy duty trucks
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60Y 2200/14 : Trucks; Load vehicles, Busses
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• 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 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A drive system of an electrically driven dump truck that

• • includes a prime mover, an electric generator, electric motors for traveling, each of which is driven by the electric power supplied from the electric generator 5 and inverters for controlling the electric motors, respectively. A total control unit calculates a correction coefficient Kp in response to the hydraulic fluid temperature detected by a thermometer 20, and then subtracts the horsepower g(Ne) for driving the other prime mover loads, which have been corrected by use of the correction coefficient Kp, from the maximum output horsepower f(Ne) of the prime mover to determine the maximum horsepower Mr that can be used by the electric motors An inverter control unit 7 determines a target torque of the electric motors on the basis of the maximum horsepower Mr so that the inverters are controlled respectively.

Claims

1. A drive system for an electrically driven dump truck which travels using the electric energy, the drive system comprising:

a prime mover;

an electric generator which is driven by said prime mover;

electric motors for traveling, each of which is driven by the electric power supplied from said electric generator;

inverters which are connected to said electric generator, and which control said electric motors;

other prime mover loads other than said electric generator, said other prime mover loads being driven by said prime mover;

measuring means for measuring the environment state quantity which fluctuates in response to ambient working environment;

correction coefficient calculation means for, on the basis of the correlation between the environment state quantity and a correction coefficient, the correlation being provided beforehand, calculating a correction coefficient (Kp) in response to the environment state quantity detected by said measuring means;

horsepower calculation means for calculating the maximum output horsepower (f(Ne)) which can be output by said prime mover, and the horsepower for driving said other prime mover loads (g(Ne)), on the basis of the target revolution speed of said prime mover or the actual revolution speed thereof;

maximum horsepower calculation means for correcting the horsepower for driving said other prime mover loads by use of the correction coefficient which has been calculated by said correction coefficient calculation means, and for subtracting the horsepower for driving said other prime mover loads after the correction from the maximum output horsepower which can be output by said prime mover, so as to determine the maximum horsepower (Mr) which can be used by said electric motors for traveling; and

inverter control means for determining the target torque (TrL, TrR) of said electric motors for the traveling on the basis of the maximum horsepower which can be used by said electric motors for traveling, the maximum horsepower having been calculated by said maximum horsepower calculation means, and for controlling said inverters on the basis of the calculated target torque.

3. The drive system for the electrically driven dump truck according to claim 1, wherein:

the environment state quantity includes the temperature (Toil) of hydraulic fluid used for said other prime mover loads; and

said measuring means includes a thermometer for detecting the temperature of the hydraulic fluid.

4. The drive system for the electrically driven dump truck according to claim 1, wherein:

the environment state quantity includes the ambient atmospheric pressure (Patm), and

said measuring means includes a barometer for detecting the atmospheric pressure.

2. A drive system for an electrically driven dump truck which travels using the electric energy, the drive system comprising:

a prime mover;

an electric generator which is driven by said prime mover;

electric motors for traveling, each of which is driven by the electric power supplied from said electric generator;

inverters which are connected to said electric generator, and which control said electric motors;

other prime mover loads other than said electric generator, said other prime mover loads being driven by said prime mover;

measuring means for measuring the environment state quantity which fluctuates in response to ambient working environment;

correction coefficient calculation means for, on the basis of the correlation between the environment state quantity and a correction coefficient, the correlation being provided beforehand, calculating a correction coefficient (K′

(Toil)) in response to the environment state quantity detected by said measuring means;

corrected horsepower calculation means for calculating the corrected horsepower (FC) on the basis of the correction coefficient calculated by said correction coefficient calculation means, and the horsepower for driving said other prime mover loads (gr(Ne));

reference target horsepower calculation means for calculating the reference target horsepower (Fr) of said prime mover in response to the operation amount (p) of the accelerator pedal;

target horsepower calculation means for calculating the target horsepower (Fr′

) of said prime mover by adding the corrected horsepower to the reference target horsepower which has been calculated by said reference target horsepower calculation means;

prime-mover target revolution speed calculation means for calculating the target revolution speed (Nr′

) of said prime mover on the basis of the target horsepower which has been calculated by said target horsepower calculation means;

fuel injection quantity control means for controlling the fuel injection quantity of said prime mover so that the actual revolution speed (Ne) gets close to the target revolution speed which has been calculated by said prime-mover target revolution speed calculation means;

horsepower calculation means for calculating the maximum output horsepower (fr) which can be output by said prime mover, and the horsepower for driving said other prime mover loads (gr), on the basis of the target revolution speed of said prime mover or the actual revolution speed thereof;

maximum horsepower calculation means for subtracting the horsepower for driving said other prime mover loads from the maximum output horsepower which can be output by said prime mover, so as to determine the maximum horsepower (Mr) which can be used by said electric motors for traveling; and

inverter control means for determining the target torque (TrL, TrR) of said electric motors for the traveling on the basis of the maximum horsepower which can be used by said electric motors for traveling, the maximum horsepower having been calculated by said maximum horsepower calculation means, and for controlling said inverters on the basis of the calculated target torque.