The Energy Management System comprises an electronic module (10) which incorporates a microcontroller (12) as a calculation engine and means for controlling various systems of an electric vehicle or other vehicle having limited energy storage. A variety of sensors including battery sensors (18), temperature sensor (20), current sensor (22), temperature sensors (24, 26, 28, 30), speed sensor (32), accelerometer (34), and ignition switch (36) provide information for the Energy Management System to derive control parameters for the systems. Automatic control of heating and air conditioning system (56), external lighting system (58) and the operation of motor controller (54) as well as display of information, status and queries to the driver are controlled by the Energy Management System and range and navigation recommendations are made based on predetermined driving profiles maintained in the system.

Energy management system for vehicles having limited energy storage

A microprocessor-based electronic voltage regulation system for controlling the charging of the battery in a vehicle. The conventional voltage regulator is eliminated and the intelligence of the microprocessor already present on the vehicle for controlling engine operation is used to regulate the output of the alternator. The battery temperature signal from a temperature transducer and a battery voltage signal from a sense line connected directly to the positive terminal of the battery are supplied to the microprocessor through an analog-to-digital converter. The microprocessor is programmed to ascertain from the battery temperature signal the desired set point voltage based upon an inverse first order relationship between battery temperature and desired battery voltage with preset maximum and minimum voltage set point levels. Energization of the field windings is controlled in accordance with a comparison between the desired set point voltage and the battery voltage signal on the battery sense line and is implemented in response to a control signal from the microprocessor by a solid-state power switching circuit which interfaces with the alternator field windings. In addition, the microprocessor is provided with additional feedback information relating to various driving conditions, such as vehicle deceleration, throttle position, engine RPM, and elapsed time since ignition, and is further programmed to modify the desired voltage set point or modify engine RPM in accordance with such driving conditions. Overcurrent protection for the logic circuitry and improved diagnostic capabilities are also provided.

Microcomputer controlled electronic alternator for vehicles

Charging and discharging of a battery are controlled while observing the state of the battery, thereby improving its efficiency and increasing battery service life. A program control circuit acquires vehicle speed from a vehicle speed sensor and the rotational speed of the internal combustion engine from a rotation sensor. The program control circuit controls an inverter which performs AC-to-DC or DC-to-AC conversion between a motor-generator coupled to the internal combustion engine and a battery mounted on the vehicle. At the same time, the program control circuit acquires the charging and discharging current (i) of the battery, which is detected by a current sensor, and calculates the time integral I of the charging and discharging current (i). The circuit controls the charging current to the battery during regenerative braking, and the discharge current when the vehicle is being driven, in accordance with a function of the time integral I. The overall life of the battery can be lengthened, and the energy lost by the brakes can be most effectively regenerated. Moreover, even if there is variability in the characteristics of the unit cells, its increase can be held in check. In addition, battery costs can be reduced and maintenance simplified.

Control system for on-vehicle battery

Battery monitoring and deceleration dependent fuel-saving charging system

Power inverter equipment monitor/controller method and apparatus are described. The invented apparatus provides for the semi-automatic state steering and monitoring of an inverter/charger and alternator system. A flat panel user interface includes an array of switches, displays and indicators for establishing modes of operation of the system, for initializing operating parameters of the system and a connected battery, for establishing rates for the system's operation, permit the user to monitor the system's operating mode and charging data (including charging efficiency factor or CEF) while it is operating to charge the battery and to supply AC power to connected appliances. By the one of the preferred methods of the invention, ramping-up the alternator's output of current, sustaining the output until the voltage of the battery is acceptable, adjusting the output while maintaining the battery voltage at an acceptable level, reducing output until float level voltage is obtained and further adjusting output to maintain float level voltage to preserve the battery charge. By the other of the preferred methods, certain charge data related to the charging of the battery--including a present CEF, maximum amp-hour charge level capacity of the battery (AH CL capacity), and the present status of amp-hour charge level--are given and stored in memory, the battery is discharged, the lowest-recorded (LR) AH CL is recorded with recharge begins, completing the recharge and storing amount of amp-hours used to recharge, determining an intermediate CEF by dividing AH used-to-recharge battery by difference between the AH CL capacity and LR AH CL, averaging the present CEF with the intermediate CEF to produce a result which is stored in memory as the present CEF, and resetting present status to the AH CL capacity.

Power conversion equipment monitor/controller method and apparatus

A system responsive to the voltage of a motor vehicle battery when the vehicle engine is not running operates to disconnect the battery from the vehicle electrical loads prior to the point at which the battery becomes too discharged to restart the vehicle engine. The apparatus which operates to disconnect the battery from the loads is inhibited if an abrupt battery voltage drop indicative of vehicle entry is sensed, and the inhibit is maintained for a timed period sufficiently long in duration to allow entry of the vehicle and starting of the engine.

Motor vehicle battery rundown protection system

A voltage regulating system for a generator that supplies the battery and electrical loads on a motor vehicle The system includes a load response control for detecting whenever a substantial electrical load is applied to the generator tending to cause a drop in generator output voltage and when such a condition is detected field current is controlled to gradually increase field current from some value The load response control includes means for storing an electrical signal that corresponds to generator field current and for utilizing this stored value to set generator field current at a value corresponding to a field current that occurred just prior to the detected drop in voltage and then increasing field current slowly from this value The system includes means for preventing a subsequent drop in detected load voltage from actuating the load response control for the time duration that field current is being slowly increased by the load response control once it has been triggered by an initial drop in voltage

Generator load response control

Direct current commutation system for brushless electrical motors

First and second batteries are connected in series between the terminals of a vehicle starting motor. The DC output terminals of a DC generator are connected across the first battery and also across a voltage sensitive switch and the oscillator transformer input stage of a DC to DC converter. The rectifier output stage of the DC to DC converter is combined with a voltage regulator that is connected across a second battery. The voltage sensitive switch renders the input stage of the converter operative when the output of the the generator is greater than a first predetermined voltage and inoperative below. The voltage regulator maintains a second predetermined voltage across the second battery by rendering the output stage of the converter operative to charge the second battery when the voltage thereon is below the second voltage and inoperative above.

Dual voltage charging system

A motor vehicle electrical system having a charge mode of operation wherein the motor vehicle battery receives charging current at a temperature compensated voltage from an engine-driven generator, and a float mode operation wherein the battery charging current is reduced to a low value, sufficient only to prevent self-discharge of the battery. The charge and float modes of operation are alternately engaged as a function of the battery state of charge. During the charge mode of operation, a sufficiently high state of charge is detected as a function of the magnitude of the charging current, and during the float mode of operation, a depleted state of charge is detected as a function of the battery voltage. A timer provides a periodic return to the charge mode of operation to sample the battery state of charge.

Leonard J. Sheldrake

Papers

Motor vehicle battery rundown protection system

Generator load response control

Direct current commutation system for brushless electrical motors

Dual voltage charging system

Charge/float motor vehicle electrical system