WO1981003249A1 - Circuit d'entrainement a deux moteurs avec commutation a courant eleve - Google Patents

Circuit d'entrainement a deux moteurs avec commutation a courant eleve Download PDF

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Publication number
WO1981003249A1
WO1981003249A1 PCT/US1980/000541 US8000541W WO8103249A1 WO 1981003249 A1 WO1981003249 A1 WO 1981003249A1 US 8000541 W US8000541 W US 8000541W WO 8103249 A1 WO8103249 A1 WO 8103249A1
Authority
WO
WIPO (PCT)
Prior art keywords
control
switches
current
power
traction
Prior art date
Application number
PCT/US1980/000541
Other languages
English (en)
Inventor
G Melocik
Original Assignee
Towmotor Corp
G Melocik
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Towmotor Corp, G Melocik filed Critical Towmotor Corp
Priority to JP56500953A priority Critical patent/JPS57500583A/ja
Priority to EP81900680A priority patent/EP0051602A1/fr
Priority to PCT/US1980/000541 priority patent/WO1981003249A1/fr
Publication of WO1981003249A1 publication Critical patent/WO1981003249A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
    • H02P5/68—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors controlling two or more dc dynamo-electric motors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B60L15/2036—Electric differentials, e.g. for supporting steering vehicles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/64—Electric machine technologies in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Definitions

  • This invention relates to electrically operated dual motor drive systems for industrial vehicles and the like and particularly to a control circuit for such systems which enhances the operation thereof under high motor current conditions.
  • Dannettell disclose overload protection systems for electric motors used in vehicles.
  • the '681 patent discloses a control system for selectively adding a number of power transistors in parallel to accommodate high current conditions in a single traction, motor.
  • U.S. Patents Nos. 3,596,154 and 3,646,414 to Gurwicz disclose systems for differentially varying the currents to the left and right wheel traction motors in a dual motor vehicle. Gurwicz, like Dannettell, proposes the use of pulse duration modulation (PDM) for varying mean motor current. In both of the Gurwicz systems the left and right traction motors are energized simultaneously but for differentially varying time periods to accommodate vehicle turning conditions as necessary.
  • PDM pulse duration modulation
  • inexpensive and highly effective overload protection means are provided for an electrically operated dual motor drive system, preferably of the type having differentially variable left and right traction motor circuits.
  • this is achieved through the use of a simple and inexpensive shunt switch for selectively interconnecting the power switches of the differentially variable left and right traction motor circuits in parallel with one another, and control means for operating the shunt switch in response to a high current condition in at least one of the motors.
  • the result is a division of the motor current between two existing power switches under high current conditions such that each power switch need only be rated at about one-half the sustained peak motor current.
  • an im provement in the operation of a differentially variable dual motor drive system is achieved through means for establishing complemental; i.e. time staggered, operating periods for the left and right traction motors, the mean current through each individual motor during its respective energization time being variable to control traction motor speed during straight ahead, reverse and turning conditions.
  • Figure 1 is a schematic circuit diagram of a dual motor system embodying the invention
  • Figure 2 is a schematic circuit diagram showing the controller from the embodiment of Figure 1 in greater detail;
  • FIG 3 is a timing diagram for the various signal quantities which are generated in the embodiment of Figures 1 and 2;
  • Figure 4 is a block diagram of an industrial vehicle to which the system of Figure 1 is applied.
  • an embodiment of the invention in an electrically operated dual motor system is shown to comprise left and right traction motor circuits 10 and 12 respectively, left circuit 10 comprising a reversible electric traction motor 14 and right circuit 12 comprising a reversible electric traction motor 16.
  • Both of the traction motor circuits 10 and 12 receive DC current from a DC power source such as the large heavy duty battery 18.
  • the mean current value through traction motor circuit 10 is controlled by a transistor power switch 20 having a sustained peak current rating which is less than the peak current which can be produced by battery 18 under low speed high torque conditions.
  • traction motor circuit 12 is connected in series with power transistor switch 22 which is substantially identical to transistor 20 and has substantially the same current rating.
  • the transistors 20 and 22 are pulse modulated to vary the mean voltage applied to the motor circuits 10 and 12 according to the desired motor speeds.
  • transistors 20 and 22 may be pulse frequency or pulse duration modulated in accordance with well-known techniques for controlling traction motor speed.
  • the mean voltages may be independently or differentially varied according to the various operating conditions of the powered device on which the traction motors 14 and 16 are mounted.
  • Circuit 10 comprises direction control contacts 24a and 24b which are closed simultaneously to operate the motor 14 in the forward direction and contacts 24c and 24d which are closed simultaneously to operate the motor 14 in the reverse direction.
  • Circuit 10 is connected in series with field winding 26 and auxiliary switching SCR 28, the cathode or output terminal of which is connected directly to the collector electrode of power transistor 20.
  • Circuit 10 further comprises a plugging diode 30 and a flyback diode 31 to provide a circulating path for current which is generated by the motor 14 when coasting; i.e. when driven by the load or its own inertia.
  • Circuit 12 comprises direction control contacts 32a and 32b which when simultaneously closed cause current to pass through motor 16 so as to operate it in the forward direction. Circuit 12 comprises further contacts 32c and 32d which when simultaneously closed operate the motor 16 in the reverse direction. Circuit 12 is connected with series field winding 34 and auxiliary switching SCR 36. The output terminal of SCR 36 is connected directly to the collector electrode of power transistor 22.
  • Circuit 12 further comprises plugging diode 38 and flyback diode 40 which provide recirculating current paths during coasting or load driven conditions.
  • Both SCR's 28 and 36 comprise primary terminals for load current and a control terminal for controlling conductivity through the primary terminals. The SCR's become conductive upon receipt of a forward biasing trigger pulse and remain conductive until primary current flow ceases.
  • Contacts 24 and 32 as well as the conductive conditions of switch devices 20, 22, 28 and 36 are controlled by means of a central controller 42 in the form of a condition responsive variable timing sequencer having various outputs hereinafter described.
  • Power source 18 is connected to high voltage line 46 through a shunt-type current sensor 44.
  • Line 4.6 is connected to the series combination of key switch 48, an operator seat switch 50 and an accelerator switch 52, the latter three elements being utilized in the application of the invention to an electric vehicle as will be further described under the heading "Industrial Applicability".
  • the high voltage line 46 is connected through a series of contact control relay coils 54 and the controller sequencer 42 to establish the conductive or nonconductive (closed or open) condition of contacts 24 and 32 in accordance with the position of the direction control switch 56, a simple relay circuit being sufficient to provide such function.
  • a full-throttle switch 57 connects the battery 18 to a bypass coil 58 which, when energized, closes bypass switches 60a and 60b to connect the lower voltage end of the field windings 26 and 34 directly to ground. Under these conditions, motors 14 and 16 are effectively connected across battery 18 and no modulation occurs.
  • An electromechanical wheel position sensor 62 responds to the position of a dirigible wheel or wheels to differentially vary the pulse duration modulation operating conditions of power transistors 20 and 22 to permit the vehicle to negotiate a turn as is well known in the art.
  • a switch comprising movable contact 64, solenoid operating coil 66 and transistor switch 68 is connected commonly between the high voltage or collector sides of power switches 20 and 22.
  • transistor 68 When rendered conductive by a signal on line 70 from controller 42, transistor 68 allows current to flow from the battery 18 through the coil 66 to close contacts 65 across the conductive element 64, placing the transistor switches 20 and 22 in parallel. Motor current flowing through traction motor circuit 10 during the on-time of SCR switch 28 is thus shared by the parallel combination of transistor switches 20 and 22.
  • auxiliary switches 28 and 36 are rendered conductive in complemental or alternately opposite fashion by control signals on lines 72 and 74 from sequencer 42, as hereinafter described.
  • traction motors 14 and 16 are energized alternately, the respective periods of potential energization being equal, and the actual times of ener gization being modulated by the combination of controller 42, position sensor 62, accelerator 63 and the transistors 20 and 22.
  • a large head capacitor 130 is connected across the source battery 18 to eliminate harmonic line voltages due to high-speed switching and, hence, improve discharge efficiency.
  • the capacitor 130 is typically located at a point which, is physically remote from the battery 18 such that the lead thereto creates a substantial inductance represented in the circuit by element 132.
  • Circuit 72 comprises an amplifier 80 and an optical coupler 82, a well known and conventional isolation device connected to the control terminal of SCR switch 28. A trigger pulse from sequencer is operative to render the switch 28 conductive for the first half of a full cycle of dual motor drive operation.
  • Circuit 74 is substantially identical, comprising amplifier 84 and optical coupler 86 for controlling the period of conductivity of SCR switch 36.
  • Circuit 90 for controlling the conductivity of transistor 20 comprises an amplifier 88 and switching transistor 92, the collector of which is connected to high voltage line 46 through the bias network 94 comprising diodes and resistors as indicated in the drawing. When transistor 92 is rendered conductive the decrease in collector potential causes transistor 96 to become conductive causing a forward bias signal to be applied through resistor 98 to power switching transistor 20.
  • Circuit 91 for controlling the conductivity of transistor 22 is substantially identical to circuit 90 and comprises amplifier 100, transistor 102, bias circuit 104 and the combination of transistor 106 and resistor 108. These specific implementations are merely for purposes of illustration.
  • Switch 56 Forward and reverse direction selection is made by means of switch 56, wheel position sensor 62, control 42 and coils 54 which control the condition of contacts 24 and 32 substantially and as previously described.
  • Key switch 48 is located near the operator station.
  • Accelerator switches 52 and 57 are arranged to be closed at initial and full throttle positions, respectively, to provide inputs to controller 42 along with desired speed from the accelerator.
  • Seat switch 50 is arranged in a known manner to close when an operator assumes a driving position on the seat.
  • the circuits of Figures 1 and 2 may be operated in a pulse frequency or pulse duration modulation mode to increase and decrease the ON-times of transistors 20 and 22 and thereby control vehicle speed.
  • the transistors are alternately rendered conductive as shown by pulses 142 and 144 of Fig. 3.
  • the high current condition is sensed by shunt current sensor 44 to provide an enable signal to controller 42 by way of line 110.
  • Controller 42 which may be a properly programmed microprocessor, responds to the high current signal on line 110 to enter a mode wherein the traction motors 14 and 16 continue to be complementally pulsed but with the transistors 20 and 22 pulsed simultaneously.
  • the : switch 64 is closed to parallel the power switching transistors 20 and 22 to accommodate the high current situation.
  • the complemental mode of operation is maintained by means of recurring and complemental SCR trigger pulses 112 and 114, pulses 112 being applied to the control terminal of SCR 28 and pulses 114 being applied to the control terminal of SCR 36.
  • the pulses 112 and 114 render the associated SCR switches conductive, i.e.
  • left traction motor SCR 28 exhibits a maximum potential ON-time represented by blocks 116 in the diagram of Figure 3 whereas the right traction motor SCR 36 is provided with an ON-time potential represented by the blocks 118 in Figure 3.
  • the trigger signal to transistor 68 which operates the share switch 64 is represented by the constant positive DC signal block 120 in Figure 3.
  • the dotted lines associated with the power transistor trigger signals 122, 124, 126 and 128 in Figure 3 indicate the effect of differential pulse duration modulation wherein the left and right power switch trigger signals 122 and 124 are increased during the ON-time 116 of left traction motor SCR 128 while the trigger signals 126 and 128 are reduced in length during the ON-time 118 of right traction motor SCR 36. Under these conditions the vehicle 134 tends to turn to the right, steering actually being provided by means of the dirigible wheel 140 associated with wheel position sensor 62 whilst the pulse duration modulation scheme described above effects a differential action due to different turning radii of the rear vehicle wheels.
  • the application of the invention has been described with reference to a three-wheeled industrial vehicle having two traction motors and a single dirigible wheel, it is equally applicable to four-wheeled vehicles having two dirigible wheels as well as track laying vehicles having no dirigible wheels.
  • the invention may be applied to other dual motor devices.
  • the programmable sequencer 42 may be replaced with equivalent hard-wiring including solenoid operated relays and a potentiometer type speed control for varying the ON-times of transistors 20 and 22.
  • pulse frequency modulation may be effected by means of a throttle controlled variable element in an oscillator tank circuit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)
  • Control Of Direct Current Motors (AREA)

Abstract

Systemes d'entrainement a double moteur a fonctionnement electrique pour vehicules industriels. Dans la technique de l'art anterieur, la protection de la surcharge de courant resultant d'un fonctionnement a faible vitesse et couple eleve demandait une plus grande complexite des circuits, consequence d'un reseau de circuits de protection supplementaire, ou un cout plus eleve, consequence de l'utilisation de transistors a courant eleve. L'invention consiste en un systeme d'entrainement a double moteur de fonctionnement electrique du type ayant des circuits moteurs de traction gauche et droit a variations differentielles (10, 12) comprenant des commutateurs de courant d'un cycle de travail variable gauche et droit (20, 22) connectant les moteurs (14, 16) independamment a une source d'energie (18), des commutateurs auxiliaires gauche et droit (28, 36) en serie avec les circuits moteurs de traction pour le fonctionnement complementaire de ces derniers et un commutateur de shunt a fonctionnement selectif (64) qui connecte les transistors de puissance (20, 22) en parallele pour des conditions de fonctionnement a faible vitesse et couple eleve. Ainsi, l'invention decrite protege le systeme des surcharges en utilisant des composants du circuit a double moteur existants et evite de compliquer davantage les circuits ou d'utiliser des transistors a courant eleve couteux.
PCT/US1980/000541 1980-05-07 1980-05-07 Circuit d'entrainement a deux moteurs avec commutation a courant eleve WO1981003249A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP56500953A JPS57500583A (fr) 1980-05-07 1980-05-07
EP81900680A EP0051602A1 (fr) 1980-05-07 1980-05-07 Circuit d'entrainement a deux moteurs avec commutation a courant eleve
PCT/US1980/000541 WO1981003249A1 (fr) 1980-05-07 1980-05-07 Circuit d'entrainement a deux moteurs avec commutation a courant eleve

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
WOUS80/00541 1980-05-07
PCT/US1980/000541 WO1981003249A1 (fr) 1980-05-07 1980-05-07 Circuit d'entrainement a deux moteurs avec commutation a courant eleve

Publications (1)

Publication Number Publication Date
WO1981003249A1 true WO1981003249A1 (fr) 1981-11-12

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Application Number Title Priority Date Filing Date
PCT/US1980/000541 WO1981003249A1 (fr) 1980-05-07 1980-05-07 Circuit d'entrainement a deux moteurs avec commutation a courant eleve

Country Status (3)

Country Link
EP (1) EP0051602A1 (fr)
JP (1) JPS57500583A (fr)
WO (1) WO1981003249A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1984002685A1 (fr) * 1983-01-05 1984-07-19 Towmotor Corp Circuit de commande limiteur de courant
EP0693822B1 (fr) * 1994-06-22 1999-03-03 Sevcon Limited Commande de moteurs électriques

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109936320A (zh) * 2019-04-26 2019-06-25 福州大学 一种基于占空比调制的双电机串联直接转矩控制方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3412301A (en) * 1965-01-06 1968-11-19 Cutler Hammer Inc Plural-motor control system for a common load with individual load sharing controls and decoupling of a motor for independent operation
US4028597A (en) * 1974-07-12 1977-06-07 The Raymond Corporation Motor control systems
US4066933A (en) * 1974-12-05 1978-01-03 Societe Generale De Constructions Electriques Et Mecaniques Alsthom Static switching device for two direct current machines
US4069445A (en) * 1975-10-28 1978-01-17 Towmotor Corporation Bypass control for a solid state switching device
US4251757A (en) * 1975-06-18 1981-02-17 Mitsubishi Denki Kabushiki Kaisha Power control system and apparatus thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3412301A (en) * 1965-01-06 1968-11-19 Cutler Hammer Inc Plural-motor control system for a common load with individual load sharing controls and decoupling of a motor for independent operation
US4028597A (en) * 1974-07-12 1977-06-07 The Raymond Corporation Motor control systems
US4066933A (en) * 1974-12-05 1978-01-03 Societe Generale De Constructions Electriques Et Mecaniques Alsthom Static switching device for two direct current machines
US4251757A (en) * 1975-06-18 1981-02-17 Mitsubishi Denki Kabushiki Kaisha Power control system and apparatus thereof
US4069445A (en) * 1975-10-28 1978-01-17 Towmotor Corporation Bypass control for a solid state switching device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1984002685A1 (fr) * 1983-01-05 1984-07-19 Towmotor Corp Circuit de commande limiteur de courant
US4514665A (en) * 1983-01-05 1985-04-30 Towmotor Corporation Current limit control circuit
EP0693822B1 (fr) * 1994-06-22 1999-03-03 Sevcon Limited Commande de moteurs électriques

Also Published As

Publication number Publication date
EP0051602A1 (fr) 1982-05-19
JPS57500583A (fr) 1982-04-01

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