JPH09117068A - Charging/discharging power module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small and lightweight charging/discharging power module for charging/discharging a battery depending on the characteristics thereof. SOLUTION: A main power supply is connected between terminals C1, C2 while a battery BT is connected between terminals C3, C4 and a control section 14 performs charging/discharging control according to a command being delivered from an electronic system connected between terminals B1, B2. In a charging mode, a switch 18 is turned to the contact (a), (c) side and a current I, being set at a current setting section 16, is fed from a power transistor Tr to the battery BT. In a discharging mode, the switch 18 is turned to the contact (b), (d) side and a current I, being set at the current setting section 16, is discharged from the battery BT through the power transistor Tr. The control section 14 performs highly accurate charging/discharging control based on a detection result RI of charging/discharging current detected at a current detecting section 20 and a battery voltage RV detected at a voltage detecting section 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge / discharge power module having both functions of charging or discharging a rechargeable battery.

[0002]

2. Description of the Related Art The structure and function of a conventional charging / discharging device is shown in FIG.
The power transistor Tr1 is turned on in the charging mode and the power transistor T1 is turned on in the discharging mode.
A charge control unit 2 for turning off r1 and a discharge control unit 4 for turning off the power transistor Tr2 in the charge mode and turning on the power transistor Tr2 in the discharge mode are provided. Further, in the charging mode, the switching switch 6 is switched and connected, in the discharging mode, it is switched and connected to the contact y, and in the open mode in which neither charging nor discharging is performed, the switching switch 6 which is in a neutral state and is not connected to both contacts x and y, and this switching switch A switching control unit 8 for controlling the switching operation of 6 is provided.

Then, the main power source 10 is connected to a predetermined input terminal P.
6 and P7, and a predetermined output terminal P8, P
By connecting the charging battery 12 between the terminals 9 and further connecting the bus of the microprocessor in the electronic system to the control terminals P1 to P5, the above-mentioned modes are set in accordance with the instruction from the microprocessor, The battery 12 is charged, discharged and opened.

To explain the operation in more detail, when a command to start charging is input from the microprocessor, the power transistor Tr1 is turned on, the power transistor Tr2 is turned off, and the changeover switch 6 is connected to the contact x.
The current from the main power source 10 flows into the battery 12 via the power transistor Tr1 and the contact x to charge the battery 12.
On the other hand, when a discharge start command is input from the microprocessor, the power transistor Tr1 is turned off, the power transistor Tr2 is turned on, and the changeover switch 6 is connected to the contact y, so that the current from the battery 12 is transferred to the power transistor Tr2 and the power transistor Tr2. Discharging is performed by flowing it to the terminal P9 at the ground level via the contact point y. Further, when a charge / discharge stop command is input from the microprocessor, the changeover switch 6 is brought into the neutral state, so that the charge / discharge device and the battery 12 are electrically disconnected.

[0005]

In such a conventional charging / discharging device, a control block having a charging control unit 2 and a power transistor Tr1 for controlling the charging operation, a discharging control unit 4 and a power transistor Tr2 for controlling the discharging operation are provided. Since the control blocks having the above are individually and separately configured, there is a problem that the volume and weight of the entire apparatus increase. For example, when realizing a small and lightweight charging / discharging device for charging / discharging a battery for a secondary battery incorporated in an electronic system such as a portable macro computer system (personal computer), it has been a great limitation.

Further, in addition to nickel cadmium (Ni-Cd) batteries which have been widely used from the past, high performance batteries such as lithium ion (Li-ion) batteries and nickel hydrogen (Ni-MH) batteries having high energy density are available. Although they were developed, these new batteries also have drawbacks in exchange for high performance, such as extremely shortened life due to overcharge status, and different initial voltage and final voltage when charging is completed. There are various problems such as large current concentrated on a specific battery due to variations in capacity when charging multiple batteries at the same time.Therefore, when charging or discharging these new batteries Requires extremely careful treatment, and development of a charging / discharging device capable of ensuring the safety of electronic systems is desired.

Further, it is desired to ensure the safety of the electronic system by monitoring and judging the characteristic changes of these new batteries in real time not only during charging and discharging but also during operation of the electronic system.

Further, in the performance test after the battery is manufactured, it is desired to precisely inspect the characteristics of these new batteries based on various test parameters.

The present invention has been made in view of these various problems, and is a small-sized and lightweight charging / discharging power module capable of performing appropriate charging / discharging according to the characteristics of a battery. The purpose is to provide.

[0010]

In order to achieve such an object, a charging / discharging power module of the present invention comprises an active element for setting a charging / discharging current and a power supply means and a battery in a charging mode. A switching means for switching and connecting the active element, and a switching means for switching and connecting the active element between a ground and a battery in a discharge mode, and a switching operation of the switching means and a set value of the charging / discharging current of the active element. And a control means.

Further, the active element, the switching means and the control means are molded with a synthetic resin material.

[0012]

In the charging mode, by switching the switching means, the active element is connected between the power supply means and the battery to be charged, and charging is performed by causing a set charging current to flow in the battery. On the other hand, in the discharge mode, the active element is connected between the ground and the battery to be discharged, and discharging is performed by causing a set discharge current to flow from the battery to the ground. Then, the control means controls each set current at the time of charging and discharging and switching control of the switching means.

Therefore, the system has a simple structure in which the charging and discharging processes are performed by the active element of one system, the switching means and the control means. Further, in addition to such a simple configuration, since this charge / discharge power module has a structure molded with a synthetic resin material, a compact and lightweight charge / discharge power module is realized.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a charge / discharge power module according to the present invention will be described below with reference to the drawings.
1 is a block diagram for explaining the circuit configuration, and FIG.
3 and FIG. 3 are block diagrams showing an example of usage of this embodiment.

To describe the configuration based on FIG. 1, there is provided a control unit 14 connected to an external electronic system or the like via external connection terminals B1 and B2, and the terminal B1 is transferred from the electronic system or the like. The terminal B2 is provided to supply a command signal to the control unit 14, and the terminal B2 is provided to transfer information signals such as an operating state in the module and a state of the battery BT from the control unit 14 to an electronic system. still,
As the control unit 14, a sequential circuit including firmware, a logic circuit, or the like, a microprocessor, or the like is applied.

The input terminals C1 and C2 are provided to connect a main power source (not shown) for supplying electric power required to charge the battery BT, and the output terminals C3 and C4 are provided to the battery BT to be charged. It is provided to connect to.
In this embodiment, the terminals C1 and C3 are positive potentials, and the terminals C2 and C4 are ground terminals commonly connected.

The current setting section 16 is responsive to the current value control signal SI supplied from the control section 14 for the power transistor T.
It has a function of a so-called variable constant current source circuit that determines the current I flowing through the collector-emitter path of the power transistor Tr by setting the base bias of r.

To the collector and emitter of the power transistor Tr, a changeover switch 18 which is changed over according to a changeover control signal Sw from the control section 14 is connected. That is, the changeover switch 18 includes a first changeover section having bidirectional contacts a and b and a second changeover section having bidirectional contacts c and d, and the first changeover section has a collector of the power transistor Tr. The emitter is connected to the second switching unit.
Further, the contact point a is connected to the terminal C1, the contact points b and c are both connected to the output terminal C3 via the current detection unit 20 described later, and the contact point d is connected to the terminals C2 and C4.

Although the details of the operation will be described later, in the charging mode, the collector of the power transistor Tr is switched so as to be connected to the contact a and the emitter thereof is connected to the contact c.
In the discharge mode, the collector of the power transistor Tr is switched to connect to the contact b and the emitter thereof is connected to the contact d, and in the open mode in which neither charging nor discharging is performed, the power transistor Tr is in a neutral state in which it is not connected to any contact.

The current detector 20 provided between the changeover switch 18 and the output terminal C3 detects the value of the current flowing into the battery BT in the charging mode, and detects the value of the current flowing out of the battery BT in the discharging mode. Detect and
It has a current detection sensor that transfers these detection results RI to the control unit 14.

The voltage detection unit 22 has a voltage detection sensor which detects the voltage between the output terminals C3 and C4 and transfers the detection result RV to the control unit 14.

The control unit 14 controls the detection result RI supplied from the current detection unit 22 in the charge / discharge mode so that the current value (target value) designated by the electronic system or the like matches.
By performing feedback control of the current value control signal SI, the current I, which is the control amount, is always made equal to the target value. The control unit 14 also detects the detection result RV from the voltage detection unit 22.
Based on the above, it is determined whether or not the battery BT is in the charging completed state, whether or not the battery BT is in the discharging completed state, or the remaining capacity of the battery BT is determined. Further, these judgment results and the detection results RI and RV are transferred to the electronic system via the terminal B2. Further, the various information signals described above are transferred to the electronic system via the terminal B2, and according to the command signal transferred from the electronic system via the terminal B1, the switching control of the changeover switch 18 and the current I by the current setting unit 16 are performed. It has a function of performing so-called polling processing for performing variable control of the above.

Then, by molding the entire circuit of such a structure with a synthetic resin material having thermoplasticity,
It is modular.

Next, the operation of this embodiment having such a configuration will be described. As described above, the main power source is connected between the terminals C1 and C2, the battery BT to be charged is connected between the terminals C3 and C4, and the charging / discharging module is provided between the terminals B1 and B2. It is assumed that a central control unit (for example, a microprocessor or the like) is connected.

First, when a command signal for starting the charging process is supplied to the control unit 14 through the terminal B1, the control unit 14
Performs the following charging operation based on the information on the charging start command included in the command signal, the voltage at the time of completion of charging of the battery BT, and the information on the charging current value. That is, by controlling the changeover switch 18 to change over by the changeover control signal Sw, the first changeover portion is connected to the contact a and the second changeover portion is connected to the contact c, and the current value control signal SI is set to the current setting. By supplying to the section 16, the current I flowing through the collector-emitter path of the power transistor Tr is made equal to the designated charging current value. Therefore, the battery BT can be charged with the constant current I, and further, the current detection unit 20
By feedback-controlling this current I based on the current detection result RI detected in step 1, an extremely stable constant current can be achieved.

When the voltage detection result RV detected by the voltage detector 22 reaches the voltage at the time of completion of charging, the changeover control signal Sw causes the changeover switch 18 to switch to the open mode and the power transistor Tr to turn off. By doing so, the charging process is ended, and at the same time, the information signal indicating the end of the charging process is transferred to the electronic system via the terminal B2.

Next, when a command signal for starting the discharge process is supplied to the control section 14 via the terminal B1, the control section 14 is started.
Performs the following discharge operation based on the information on the discharge start command included in the command signal, the voltage at the time of completion of discharge of the battery BT, and the information on the discharge current value. That is, by controlling the changeover switch 18 to change over by the changeover control signal Sw, the first changeover section is changed over to the contact b and the second changeover section is changed to the contact d, and further the current value control signal SI is set to the current setting. By supplying to the portion 16, the current I flowing through the collector-emitter path of the power transistor Tr is made equal to the specified discharge current value.

Therefore, the battery BT can be discharged with the constant current I, and further, the current I is feedback-controlled on the basis of the current detection result RI detected by the current detection unit 20, so that a very stable constant current is obtained. A current is achieved.

When the voltage detection result RV detected by the voltage detection unit 22 reaches the voltage at the time of completion of the discharge, the changeover control signal Sw switches the changeover switch 18 to the open mode and the power transistor Tr is turned off. By doing so, the discharge process is ended, and at the same time, a signal indicating the end of the discharge process is transferred to the electronic system via the terminal B2.

Although a typical charging / discharging operation has been described, other functions can be achieved by variously changing the information (content) of the control signal transferred from the electronic system to the control unit 14.

For example, when the charging current value (target value) is variably designated in the charging mode, the battery BT
Since the charging current I to the battery can be variably controlled, optimum charging according to the characteristics of the battery BT is possible. On the other hand, also in the discharge mode, similarly, the discharge current I to the battery BT can be variably controlled by variably designating the discharge current value (target value), so that the optimum discharge according to the characteristics of the battery BT can be performed. to enable. As a result, charging / discharging can be performed without deteriorating the performance of the lithium-ion battery, the nickel-hydrogen battery, or the like, which has been a conventional problem.

In addition, the electronic system issues a command to the control section 14 to intermittently perform charging / discharging, or continuously monitors a change in the capacity of the battery BT during a period in which charging / discharging processing is not performed. Enable monitoring.

Further, since the circuit configuration is such that one power transistor Tr and one current setting section 16 associated therewith perform both charge and discharge processing, the circuit can be simplified by greatly reducing the number of parts. Weight reduction is possible, and a compact and lightweight charging / discharging power module is realized. As a result, for example, a charging / discharging system for charging / discharging a secondary battery of a portable electronic system can be realized in a small size and a light weight, which can greatly contribute to the reduction in size and weight of the electronic system. Further, by applying this charging / discharging power module to an electronic system that requires a large number of secondary batteries such as an automatic call exchange system, it is possible to greatly contribute to downsizing and weight saving of the electronic system.

The charge / discharge power module can also be applied to a performance test of the battery BT, etc. in addition to the charge / discharge processing. That is, when the changeover switch 8 is switched and connected to the contacts b and d to set the same state as in the discharge mode and further set the current I flowing through the power transistor Tr to the current setting unit 16 to a constant value, This can be made equivalent to connecting a constant resistance active load to both ends of the battery BT, and the resistance value can be variably set according to the value of the current I. Therefore,
This charging power unit can be applied as a so-called electronic load device to perform a load test, and further, the characteristics of the battery BT can be observed in real time based on the output signal from the control unit 14. Further, in the same manner, it can be applied as a so-called dropper power supply. Thus, according to this charge / discharge power module, a battery test system can be configured.

By combining a plurality of such charging / discharging power modules and connecting them in series or in parallel, the charging / discharging capacity can be improved.

FIG. 2 shows an example in which a plurality of modules are connected in parallel to the battery BT. According to such parallel connection, since charging / discharging can be performed with a current that is multiple times the current I that can be charged / discharged by one module, it is possible to rapidly charge / discharge a large number of batteries. .

FIG. 3 shows an example in which a plurality of modules are connected in series. For example, a plurality of batteries connected in series can be charged.

In the description of this embodiment, the case where the power transistor is used as the active element has been described.
The present invention is also achieved using other types of active devices such as field effect transistors (FETs).

[0039]

According to the present invention as described above,
Since the charging / discharging process is performed by one system of active elements, switching means, and control means, the charging / discharging power module can be small and lightweight.
Further, by making this charging / discharging power module molded with a synthetic resin material, a small and lightweight charging / discharging power module can be provided.

Furthermore, in the charging / discharging device provided with the two systems of the charging system and the discharging system of the prior art, it is necessary to radiate the heat generated from these two systems to the outside, so that a large radiator is required. On the other hand, in the present invention, since only one system is charged and discharged, a small radiator is sufficient, and various electronic systems can be made compact and lightweight. Further, it becomes possible to easily realize commonization of power blocks and the like.

Furthermore, since the charging / discharging current can be controlled in a so-called programmable manner by the control means, it has a wide range of functions such that it can be used for an electronic load device, a dropper power source, etc. in addition to the normal charging / discharging function. Have

Further, it is possible to connect a plurality of charging / discharging power modules of the present invention in parallel or in series, and it has an excellent function that the charging / discharging capacity can be easily improved.

Further, the modularization allows easy attachment / detachment to various electronic systems and contributes greatly to the simplification of the configuration of the electronic system. Also,
Such modularization also contributes to standardization of the charging / discharging system.

As described above, the charging / discharging power module of the present invention has many functions in addition to being small and lightweight, and therefore is applied to various electronic systems and exhibits excellent effects.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a circuit configuration of an embodiment of a charge / discharge power module according to the present invention.

FIG. 2 is a block diagram showing an example of a circuit in which a plurality of charge / discharge power modules are connected in parallel.

FIG. 3 is a block diagram showing a circuit example in which a plurality of charge / discharge power modules are connected in series.

FIG. 4 is a block diagram for explaining a circuit configuration of a conventional charging / discharging device.

[Explanation of symbols]

14 ... Control unit, 16 ... Current setting unit, 18 ... Changeover switch, 20 ... Current detection unit, 22 ... Voltage detection unit, a, b,
c, d ... Contact, B1, B2 ... External connection terminal, C1, C2
... input terminals, C3, C4 ... output terminals, BT ... battery.

Claims (2)

[Claims] 1. An active element for setting a charging / discharging current, the active element being switched and connected between a power supply means and a battery in a charging mode, and the active element being connected between a ground and a battery in a discharging mode. A charging / discharging power module comprising switching means for switching and connecting elements, and control means for controlling a switching operation of the switching means and a set value of the charging / discharging current of the active element. 2. The charge / discharge power module according to claim 1, wherein at least the active element, the switching means and the control means are molded with a synthetic resin material.