Vehicle-mounted electrical generator control system enabling suppression of supply voltage spikes that result from disconnecting electrical loads

• US 20050269880A1
• Filed: 06/08/2005
• Published: 12/08/2005
• Est. Priority Date: 06/08/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Konishi, Toshiya
• Granted Patent: US 7,329,966 B2
• Time in Patent Office: Days
• US Class Current: 307/10.700
• CPC Class Codes: H02H 3/021 concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order disconnection at zero value in general H03K17/18
• CPC Class Codes: H02H 7/067 on occurrence of a load dump control on sudden change of load H02P9/10
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02P 9/102 for limiting effects of transients

Abstract

A vehicle generator control system detects a time point at which an electrical load is to be disconnected from the generator output, with the detection being achieved prior to that disconnection time point, and initiates a lowering of the generated current of the generator by an amount equal to the load current of that electrical load. The generated current of the generator is thereby reduced, by the time of the disconnection, to a value whereby substantially no voltage spike is produced in the generator output voltage.

Claims

1. A vehicle-mounted electrical generator control system for controlling an electrical generator that is driven by a vehicle engine, said electrical generator producing a generated current for supplying a load current to at least one electrical load and a charging current of a battery of said vehicle, said system including:

voltage regulator means for controlling said electrical generator to produce a regulated output voltage, and

generator control means for deriving a currently obtained value of said generated current and for calculating a target value of said generated current and for sending target command information indicative of said target value to said voltage regulator means, said target value being determined based upon factors including a condition of said storage battery and a utilization status of said electrical load(s);

wherein said generator control means comprises

load disconnection timing detection means for detecting a disconnection time point, at which a specific electrical load is to be disconnected from said electrical generator, with said disconnection time point being detected at a pre-disconnection time point prior to said load disconnection time point, based on condition information relating to said specific electrical load,

generated output calculation means for calculating, as a specific load current value, a value of current that is being supplied to said specific electrical load, based on a value of electrical power that is being consumed by said specific electrical load prior to said disconnection, and

generated output control command means responsive to information from said load disconnection timing detection means and said generated output calculation means for transmitting to said voltage regulator means, prior to said disconnection time point, target command information specifying a value of said generated output current that is decreased from said currently obtained value thereof by an amount equal to said specific load current value.

2. A vehicle-mounted electrical generator control system according to claim 1, wherein said target command information is transmitted to said voltage regulator means at a time point substantially coincident with said pre-disconnection time point, and wherein a duration of a time interval between said pre-disconnection time point and said disconnection time point is predetermined as a specific fixed value.

3. A vehicle-mounted electrical generator control system according to claim 1, wherein said condition information relating to said specific electrical load is derived from a timer whose operation is started when said specific electrical load becomes connected to said output voltage of said electrical generator.

4. A vehicle-mounted electrical generator control system according to claim 1, wherein said specific condition information relating to said specific electrical load is derived from a sensor which detects parameter values relating to said specific electrical load.

5. A vehicle-mounted electrical generator control system according to claim 1, wherein:

said generator control means calculates an optimum value of generated current to be produced by said electrical generator following disconnection of said specific electrical load, with said optimum value being calculated based on said value of load current that is being supplied to said specific electrical load and on at least one of a plurality of vehicle-related conditions that include a value of said generated current prior to disconnection of said specific electrical load, a state of charge of said battery, a speed of rotation of said vehicle engine, and a temperature of said engine; and

said generator control means supplies target command information indicative of said optimum value of generated current to said voltage regulator means, prior to said disconnection of said specific electrical load.

6. A vehicle-mounted electrical generator control system according to claim 1, wherein said generator control means selectively supplies to said voltage regulator means said target command information designating a reduced value of said generated output current, in accordance with a state of charge of said storage battery.

7. A vehicle-mounted electrical generator control system according to claim 1, wherein said voltage regulator means and said generator control means are connected for communication via a data communication network in which multiplexed communication is executed via a single signal line.