JPH04299034A - Battery charge controller - Google Patents

Abstract

PURPOSE:To always maintain a battery in a fully charged state by not only deciding a basic generating amount to be generated by a generator in response to a terminal voltage of the battery but also correcting the generating amount even by a voltage drop of the battery when a starter is operated and a temperature of the air to be sucked to an engine. CONSTITUTION:A terminal voltage of a battery 204 is detected by a battery terminal voltage detector 205 and sent to a controller 220. In order to evaluate a deteriorating degree of the battery 204, a battery terminal voltage at the time of conducting the starter 205 requiring a highest predetermined current is detected by a start time voltage detector 207, and sent to the controller 220. Further, in order to detect the operating temperature of the battery 204, suction air temperature detector 209 of the suction air to an engine 201 is used, and a detected value is sent to the controller 220. A generating amount command value of a generator 203 calculated by the controller 220 is sent from the controller 220 to a rotor coil current controller 210.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging control device for a battery installed in an automobile, and more particularly to a charging control device that prevents the battery from being overcharged and always maintains it in a fully charged state. .

0002

[Prior Art] It is well known that automobiles are equipped with batteries to drive the starter, lights, and actuators, and that the consumed electricity is replenished by the electricity generated by the generator driven by the engine. be. Lead batteries are generally used as batteries for automobiles, but overcharging and overdischarging shorten the battery life.

For this reason, a control device is used that monitors the terminal voltage of the battery, cuts off the power supply from the generator when the terminal voltage reaches a specified voltage, and resumes charging when the battery voltage drops. It is common that

0004

However, since such a control method simply monitors the terminal voltage of the battery, it has the following drawbacks. 1)
When the battery is deteriorated, the internal resistance of the battery increases. For this reason, when a large current flows, such as when the starter is driven, the voltage drop becomes even greater, and it may become impossible to start the engine. 2) When the ambient temperature decreases, the internal resistance of the battery increases, and engine startability similarly deteriorates.

[0005] The present invention has been devised in view of this problem, and it is possible to always maintain a battery in a fully charged state by taking into consideration the degree of deterioration of the battery, the current flowing through a load such as a starter, and the ambient temperature. The purpose of the present invention is to provide a battery charging control device that

[0006]

[Means for Solving the Problems] FIG. 1 is a basic configuration diagram of a battery charging control device according to the present invention, in which battery terminal voltage detection means 1 for detecting the terminal voltage of a battery.
01, a basic power generation amount command value calculation means 102 that calculates the basic power generation amount based on the battery terminal voltage detected by the battery terminal voltage detection means 101, and a start voltage detection means 103 that detects the battery terminal voltage when the starter is energized. , a drop voltage calculation means 104 that calculates the deviation voltage between the battery terminal voltage detection means 101 and the start voltage detection means 103, and a drop voltage calculation means 104 that calculates a voltage drop correction value from the voltage drop value calculated by the voltage drop calculation means 104. Voltage correction value calculation means 105, intake air temperature detection means 106 for detecting the temperature of air taken into the engine, and intake air temperature detection means 106.
An intake air temperature correction value calculation means 107 that calculates an intake air temperature correction value based on the intake air temperature detected by the above, a basic power generation amount command value calculation means 102, and a voltage drop correction value calculation means 105.
and a power generation command value calculation means 108 that calculates a power generation command value based on the intake air temperature correction value calculation means 107, and adjusts the current flowing through the rotor winding of the generator based on the calculation result of the power generation command value calculation means 108. and a current adjustment means 109.

[0007]

[Operation] According to the battery charging control device according to the present invention, not only the basic power generation amount to be generated by the generator is determined according to the terminal voltage of the battery, but also the battery voltage when the starter, which is the largest load, operates. The amount of power generation is also corrected based on the amount of fall in air and the temperature of the air taken into the engine.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a diagram showing the configuration of a charging circuit using a battery charging control device according to the present invention, and is mainly configured with a control device. The rotational force of the engine 201 is transmitted to the generator 203 by the pulley belt 202 to rotate the rotor 2031.

The rotor 2031 is excited by the rotor coil wound around the rotor 2031, and the stator 2
A voltage is induced in the stator coil wound around 032. This voltage is converted into direct current by a rectifier 203 and supplied to a battery 204 to charge the battery 204. Note that in a DC circuit, a ground is used on the negative voltage side.

The terminal voltage of battery 204 is detected by battery terminal voltage detector 205 and sent to control device 220 . Further, a load such as an engine starter 206 is connected to the battery 204, and in order to evaluate the degree of deterioration of the battery 204, the starter 205, which requires the largest current, has a starting voltage detector 207 that detects the battery terminal voltage when energized. is detected and sent to the control device 220.

An ignition switch 208 is provided between the battery 204 and the starter 206, and when starting the engine 201, the switch 208 is turned on to supply power to the starter 206. The fact that the ignition switch 208 is turned on is also sent to the control device 220.

In addition, an intake air temperature detector 209 to the engine 201 is used to detect the operating temperature of the battery 204, and the detected value is sent to a controller 220. The power generation amount command value of the generator 203 calculated by the control device 220 is sent from the control device 220 to the rotor coil current control device 210. This rotor coil current control device 210 controls the current supplied from the battery 204 to the rotor coil of the generator 203, and is configured to be able to adjust the amount of power generation in proportion to the supplied current. Well known PWM controllers can be used.

The control device 220 is composed of a microcomputer system, and includes a CPU 2201 and a memory 220.
2. Bus 2203 and ignition switch 208
An analog input interface 220 for inputting analog signals such as the battery terminal voltage detector 205, etc.
5. It consists of an analog output interface 2206 that outputs a power generation command value to the current control device 210.

The power generation amount command value is calculated by executing a program stored in memory 2202 by CPU 2201. FIG. 3 is a flowchart of a calculation routine for the power generation amount command value, which is executed at regular intervals. In step 301, the intake air temperature Ta detected by the intake air temperature detector 209 is read.

In step 302, it is determined whether or not the ignition switch 208 is on, and if it is not on, the battery terminal voltage VB detected by the battery terminal voltage detector 205 is read in step 303, and if it is on, it is determined in step 304. When starting with terminal voltage detector 207
Read the terminal voltage VS detected at start. Step 303 or Step 304 to Step 30
Proceeding to step 5, the difference in terminal voltage between the no-load state and the loaded state of the battery 204 is calculated as the voltage drop Vd.

[0016]Vd=VB-VS

(1) Next, in step 306, a basic power generation amount command value Gb is calculated as a function of the battery terminal voltage VB. Gb = fb (VB)

(2) In step 307, a voltage drop correction value ηd is calculated as a function of the voltage drop Vd. This has the meaning of correcting the amount of power generation based on the degree of deterioration of the battery 204, since the voltage drop Vd can be considered to represent the degree of deterioration of the battery 204.

[0017] ηd = fd (Vd)

(3) Furthermore, in step 308, the intake air temperature correction value ηa is determined as a function of the intake air temperature Ta.
is calculated. This has the meaning of correcting changes in characteristics of the battery 204 due to ambient temperature. ηT = fT (Ta)

(4) Then, in step 309, a power generation amount command value GS is calculated using the following equation.

GS=Gb・(1+ηd)・ηT

(5) Finally, in step 310, this power generation amount command value GS is output to the current control device 210, and this routine ends.

[0019]

[Effects of the Invention] According to the present invention, since the battery is always maintained in a fully charged state in consideration of the degree of deterioration of the battery,
Not only can overcharging and overdischarging be prevented and the life of the battery can be extended, but also the starter can be easily driven even when the battery has deteriorated.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of a battery charging control device according to the present invention.

FIG. 2 is a configuration diagram of an embodiment of a battery charging control device according to the present invention.

FIG. 3 is a flowchart of a power generation command value calculation routine.

[Explanation of symbols]

101...Battery terminal voltage detection means 102...Basic power generation command value calculation means 103...Start voltage detection means 104... Voltage drop calculation means 105... Voltage drop correction value calculation means 106...Intake air temperature detection means 107...Intake air temperature correction value calculation means 108...Power generation command value calculation means 109...Current adjustment means

Claims (1)

[Claims] 1. A battery terminal voltage detection means (101) for detecting the terminal voltage of a battery, and a basic method for calculating the basic power generation amount based on the battery terminal voltage detected by the battery terminal voltage detection means (101). A power generation command value calculating means (102), a starting voltage detecting means (103) for detecting the battery terminal voltage when the starter is energized, the battery terminal voltage detecting means (101), and the starting voltage detecting means (103). a voltage drop calculation means (104) for calculating a voltage deviation between the voltage drop and the voltage drop calculation means (104);
Voltage drop correction value calculation means (105) for calculating a voltage drop correction value from the voltage drop value calculated by , and intake temperature detection means (106) for detecting the temperature of air taken into the engine.
, an intake air temperature correction value calculation means (107) for calculating an intake air temperature correction value based on the intake air temperature detected by the intake air temperature detection means (106), the basic power generation amount command value calculation means (102), Power generation command value calculation means (108) for calculating a power generation command value based on the voltage drop correction value calculation means (105) and the intake air temperature correction value calculation means (107).
and current adjustment means (109) that adjusts the current flowing through the rotor winding of the generator based on the calculation result of the power generation command value calculation means (108).