JPH11113185A - Charging apparatus by commercial and regenerative power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging apparatus, compatible with commercial power and regenerative power, which can charge at an optimum voltage and an optimum current from both a commercial power supply and a regenerative current, even when the performance of a battery mounted on a vehicle is irregular, which prevents overcharging and which can prolong the life of the battery. SOLUTION: A plurality of battery rows 1 which are connected in series are connected to a regenerative motor 3 via a diode 41 . Secondary sides of a plurality of DC-DC converters 51 ...5n , in which current-limiting regulators are installed a inside are connected respectively in parallel with batteries E1 ...En which are connected in series. Then, an AC-DC converter 7, which is connected to a commercial power supply 6 is connected in parallel with the secondary of the DC-DC converters 51 ...5n . In addition, a changeover device, which changes over limit current values to be set by the current-limiting regulators at the DC-DC converters 51 ...5n by the operation of the SC-DC converter 7, is installed. In addition, a diode 43 is installed between the regenerative motor 3 and primary sides of the DC-DC converters 51 to 5n .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shared charging device capable of charging a series-connected battery used for a drive motor (regeneration motor) of a hybrid vehicle or an electric vehicle from both a commercial power supply and a regenerative current. It is.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles such as trucks and passenger vehicles using a combination of an engine and a motor have been used due to pollution problems. This is to add the power of the motor and reduce the load on the engine when the engine is subjected to a heavy load and generates black smoke exhaust gas, such as when starting up with acceleration or traveling uphill. By reducing the number, the generation of harmful exhaust gas is reduced.

[0003] A regenerative motor is used as a motor used in such a hybrid vehicle. When a driving force of the motor is not required, such as when traveling downhill or when a brake is applied, the rotation force of the wheels is used. Conversely, the motor is forcibly rotated to act as a generator, and the current generated at this time is charged in a battery (battery). Similarly, electric vehicles also use a regenerative motor, which acts as a generator when driving downhill or when braking is not required, such as when braking is applied, so that the generated current is charged into the battery. Has become.

As described above, a power source of a regenerative motor used for a hybrid vehicle or an electric vehicle is mounted on a vehicle by connecting a number of batteries in series. In the conventional power supply structure, a regenerative motor is connected to both ends of a series-connected battery row.When power is supplied to the regenerative motor, current is supplied from the plus side of the series-connected battery row, and reversely charged In this case, current flows from the plus side.

[0005] In addition, batteries have some variations in characteristics at the time of manufacture, and heat radiation conditions vary depending on the battery arrangement at the time of charging. Therefore, the optimum charging voltage also differs for each battery. In the series charging by the regenerative current generated from the regenerative motor, a battery with good performance and a battery with poor performance are connected in series and charged, so even if the difference in the internal resistance of the battery is small in the initial state, each time the series charging is repeated. In addition, the variation in battery capacity gradually increases, and there has been a problem that the life of even a high-performance battery is extremely reduced due to repeated overcharging of a low-performance battery and uncharging of a good battery.

For this reason, conventionally, a charging device is connected in parallel for each battery and charging is performed at an optimum charging voltage by a regenerative current. The regenerative current generated by the regenerative motor mounted on the vehicle is generated intermittently when driving downhill or when braking is applied.
Since a large current of about 00 A is generated in a short time, the battery is converted into an optimum charging voltage and charged by a charging device connected in parallel for each battery. Also, when charging from a commercial power supply due to insufficient regenerative current alone, the voltage and current from the commercial power supply are stable, so each battery must be connected to the commercial power supply without passing through a charger connected in parallel. Another charging device was directly connected to the beginning and end of the battery row to charge.

[0007] However, when charging from a commercial power supply, even if there is variation in battery performance, the battery is charged directly to the battery array. Therefore, even if there is only one battery with poor performance, even a good battery becomes insufficiently charged. There is a problem that the life of the battery is extremely reduced due to repetition of non-charging. Note that charging from regenerative current does not result in overcharging of the battery due to the short conduction time even when the current is large, but charging from a commercial power supply with stable voltage and current may result in overcharging of the battery. was there.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has been made to solve the above-mentioned problems. Therefore, even if the performance of a battery mounted on a vehicle varies, the battery can be charged with an optimum charging voltage and current from both a commercial power supply and a regenerative current. And a commercial regenerative battery charger that prevents overcharge and extends the life of the battery.

[0009]

According to a first aspect of the present invention, there is provided a commercial regenerative charging device in which a plurality of battery strings connected in series are connected to a regenerative motor via a backflow preventer, and a current limiter is internally provided. The secondary sides of a plurality of DC-DC converters provided with a regulator are connected in parallel to the series-connected batteries, respectively, and the AC-DC converter connected to the commercial power supply is connected to the D-DC converter.
Connected in parallel to the primary side of a C-DC converter, and
A switch is provided for switching the limiting current value provided in the current limiting regulator of each DC-DC converter by operating the DC-DC converter, and a reverse current flows between the regenerative motor and the primary side of the DC-DC converter. It is characterized by having a preventer.

Further, in the commercial regenerative charging device according to the present invention, the connecting portion between the negative output terminal of the DC-DC converter and the positive output terminal of the DC-DC converter adjacent thereto is connected to each DC. The battery is connected to a connection between a negative output terminal of a battery corresponding to the DC converter and a positive output terminal of a battery adjacent thereto by an output cable.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described in detail with reference to FIG. In FIG.
A plurality of battery E _1, the E _2, E ₃ ... E _n ends of the battery banks 1 connected in series are connected to the regenerative motor 3 of 3 phases by way of an inverter 2, a starting end of the positive side of the battery array 1 diode 4 ₁ as a backflow preventer between the inverter 2 are provided. Each battery E ₁ , E ₂ , E _{3 in} battery row 1 ...
E each of the _n DC over DC converter 5 _1, 5 _2, 5 ₃ ...
5 _n secondary sides are connected in parallel.

[0012] positive output terminal of the DC over DC converter 5 ₁ output to the positive output terminal of the battery array 1 cable 10a
Connected by Furthermore a negative output terminal of the DC over DC converter 5 _1, DC over DC converter 5 ₂ adjacent thereto
The connection line 8a connecting the positive output terminal of the
Are connected by output cables 10b to the _first negative output terminal and the connection line 9a of the positive side output terminal of the battery E ₂ adjacent thereto. Below as well as negative output terminal of the DC over DC converter 5 _2, DC over DC converter adjacent to the 5
Connection line 8b which connects the _third and positive output terminal is connected to the output cable 10c to the connection line 9b of the positive side output terminal of the battery E ₃ adjacent thereto and the negative output terminal of the battery E ₂ .

Reference numeral 6 denotes a commercial power supply, to which an AC-DC converter 7 having a low frequency and a high power factor is connected. This AC-DC
Positive output terminal of the converter 7 via a diode 4 ₂ as a backflow preventer, it is connected in parallel to the positive input terminal of the primary side of the DC over DC converter 5 ₁ ... 5 _n. The negative output terminal of the AC over DC converter 7 is connected in parallel to the negative input terminal of the primary side of the DC over DC converter 5 ₁ ... 5 _n. Further positive input terminal of the inverter 2 via the diode 4 ₃ serving as a backflow preventer, is connected in parallel to the positive input terminal of the primary side of the DC over DC converter 5 ₁ ... 5 _n.

The internal configuration of the DC-DC converters 5 ₁ ... 5 _n is such that the smoothing circuit 14 to which the AC-DC converter 7 connected to the commercial power supply 6 is connected as shown in FIG. It is connected to the primary side of the transformer 16 through the. The secondary side of the transformer 16 is connected via a rectifier circuit 17 to a smoothing circuit 18.
It is connected to, which is further connected to the battery E ₁ ... E _n through the base plate 19. On the primary side of the transformer 16, an overheat protection circuit 20 is provided, which is connected to an on / off control 22 via a control unit 21 so as to shut off a power supply circuit. Auxiliary power supply connected to power circuit
24 is connected to a primary side of a transformer 25, and a secondary side of the transformer 25 is connected to a terminal voltage detector 27 via a control unit 26.

The secondary side of the transformer 16 and the rectifier circuit 17
Between them, a current limit adjuster 29 is connected, to which a switch 11 for detecting the operation of the AC-DC converter 7 and switching the limit current value is connected. Current limit adjuster 29
Is connected to the control unit 26, and further comprises a photocoupler.
It is connected via 30 to a control unit 21 provided on the primary side.
Further, between the smoothing circuit 18 provided on the secondary side of the transformer 16 and the base plate 19, an overvoltage protection circuit 32 is provided, which is connected to a control unit 21 provided on the primary side via a photocoupler 31.
It is connected to the.

In the device of the above circuit, when a heavy load is applied to the engine, such as when the hybrid vehicle accelerates and starts, or when traveling uphill, as shown in FIG. drive current I _i is converted to 3-phase AC through the inverter 2 drives is supplied to the regenerative motor 3 acts as an auxiliary power of the engine.
During this time, the battery E _1, E ₂ ... E _n is going to consumption gradually.
When the driving force of the motor is not required, such as when traveling downhill or when a brake is applied, the regenerative motor 3 is forcibly rotated by the rotational force of the wheels to act as a generator.

The regenerative current of the three-phase alternating current generated at this time is converted into direct current by the inverter 2, and this regenerative direct current I ₀
Flows to the positive input terminal of the diode 4 ₃ DC over DC converter 5 ₁ connected in parallel via, 5 ₂ ... 5 primary of _n. At this time, the regenerative current by the diode 4 ₁ current I ₀
5n side is prevented from flowing back to the DC-DC converters 5 ₁ , 5 ₂ ... _5n side, and the diode 4 ₂ is prevented from flowing back to the AC-DC converter 7 side. FIG. 1
The circuit of the inverter 2 shown in FIG. 1 shows a circuit for converting three-phase alternating current generated from the regenerative motor 3 into direct current.

In the DC-DC converters 5 ₁ , 5 _2, ... 5 _n , as shown in FIG. 2, after the large-capacity DC regenerative current is smoothed by the inverter 2 and further smoothed by the smoothing circuit 14, The high-frequency current is converted by the switching circuit 15 and flows to the primary side of the transformer 16, and is converted to a charging voltage of about 14.5 V on the secondary side. The converted current is charged to the battery E ₁ deprived of noise is smoothed by the smoothing circuit 18 is rectified into DC by the rectifier circuit 17.

[0019] In this case, it is charged current I ₁ flows to the battery E _1, E ₂ ... E _n connected in series as shown in FIG. Referring first charging of the battery E ₁ is the voltage at the time is completed is increased to the optimal voltage, the current I ₁ increases the internal resistance of the battery itself is lowered. Thereafter, the current I ₂ through the output cable 10b from the DC over DC converter 5 ₂ to the battery E ₂
Flow out increases gradually increases until the charging voltage is the optimal voltage at completion of the battery E _2, come reduces the current I ₂ further beyond the peak.

That is, the battery E ₂ is charged by the sum of the currents I ₁ and I ₂ . Battery E ₃ through the output cable 10c from Similarly DC over DC converter 5 ₃ below
To increase gradually flows out current I _3, when the charging of completing the battery E _3, rises until the voltage optimum voltage, further the charging is completed by lowering the current I ₃ beyond the peak. Therefore, even if the battery performance varies, each battery E ₁ , E ₂ .
DC over DC converter provided in parallel so as to correspond to E _n 5 _1, 5
_{From 2} ... 5 _n, it is possible to charge with the optimum charging voltage and current respectively.

In this charging process, the DC-DC converter 5 ₁
, As shown in FIG. 2, detects the voltage of the output terminal of the battery E ₁ in the terminal voltage detector 27 outputs a signal to the photo coupler 30 when the detected voltage by the control unit 26 rises above defined , When this is detected by the control unit 21, the on / off control
The power is turned off by operating the 22. Further, the voltage on the secondary side of the transformer 16 is detected by the overvoltage protection circuit 32, and when the detected voltage rises above a specified value, a signal is output to the control unit 21 via the photocoupler 31, and this is output to the control unit.
When the detection is made at 21, the on / off control 22 is operated to cut off the power.

Further, the current on the secondary side of the transformer 16 is detected by the current limit adjuster 29, and when the detected current rises beyond a specified value, a signal is sent to the control unit 21 via the control unit 26 and the photocoupler 30. From here, the on / off control 22 is operated to shut off the power. In this case, since a large current of about 100 A to 200 A flows in a short time as the regenerative current, the limit value of the current limit adjuster 29 is set to a high value.

[0023] When only the regenerative current for charging from the commercial power source 6 becomes insufficient charging is by the operation of AC over DC converter 7, provided in each DC over DC converter 5 _1, 5 ₂ ... 5 _n switcher 11 is operated to lower the limit value of the current limit adjuster 29 to a lower value. This is not a limitation to the input power from the commercial power source 6, since there optimal for a long period of time exceeds the charging current for charging the battery E _1, E ₂ ... E _n are possibly battery is overcharged to damage to the battery capacity It is.

[0024] from the alternating current from the commercial power source 6 is converted into direct current in AC over DC converter 7, the direct current DC over DC converter _{5 1, 5 2, 5 3} ... 5 n primary side input terminal Flows to Note is prevented by the diode 4 ₃ as current at this time does not flow back to the inverter 2 side. D
The DC current flowing through the C-DC converters 5 ₁ , 5 ₂ , 5 ₃ ... 5 _n is adjusted to an optimum charging voltage via the smoothing circuit 14, the switching circuit 15, and the transformer 16, and then flows into the rectifier circuit 17. is adjusted by the current limiting regulator 29 to the optimal charging current is switched set, battery E ₁ be charged long, E _2, E
₃ ... E _n is made so as not to over-charging.

In the above description, the regenerative motor 3 is 3
Although the case where the phase motor is mounted on the vehicle is described, when the DC motor is mounted, the inverter 2 is unnecessary. The AC-DC converter 7 is a DC-DC converter 5
_1, 5 ₂ ... 5 may be mounted integrally with the vehicle with _n, or may be a configuration provided separately. Further diodes 4 ₁ as backflow preventer, 4 _2, 4 ₃ may be used a switch circuit shows the case of using the.

[0026]

As described above, according to the commercial regenerative charging device according to the present invention, the AC-D connected to the commercial power supply
C converter is provided corresponding to the battery connected in series.
Connected in parallel to the primary side of the C-DC converter, and by the operation of the AC-DC converter, the limiting current value provided in the current limiting regulator of each DC-DC converter is changed between the commercial current and the regenerative current. By switching, even if the performance of the battery mounted on the vehicle fluctuates, it is possible to charge the battery with the optimum charging voltage and current from both the commercial power supply and the regenerative current, and to prevent overcharging and extend the life of the battery Can be achieved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a commercial regenerative charging device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an internal configuration of the DC-DC converter shown in FIG.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Battery row 2 Inverter 3 Regenerative motor 4 Diode 5 DC-DC converter 6 Commercial power supply 7 AC-DC converter 8a Connection line 9a Connection line 10a Output cable 11 Switching device 15 Switching circuit 16 Transformer 17 Rectifier circuit 26 Control part 29 Current Limiter E Battery

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[Procedure amendment]

[Submission date] November 4, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (2)

[Claims] 1. A plurality of battery strings connected in series are connected to a regenerative motor via a backflow preventer, and a secondary side of a plurality of DC-DC converters provided with a current limit adjuster is connected to the secondary side. An AC-DC converter connected to a battery connected in series and connected to a commercial power supply is connected in parallel to a primary side of the DC-DC converter, and the AC-DC converter is operated by the AC-DC converter. A switching device for switching a limiting current value provided in a current limiting regulator of each DC-DC converter, and a backflow preventing device provided between the regenerative motor and the primary side of the DC-DC converter. Features a commercial regenerative shared charging device. 2. A connection between a negative output terminal of a DC-DC converter and a positive output terminal of an adjacent DC-DC converter is connected to a negative side of a battery corresponding to each DC-DC converter. 2. The commercial regenerative charging device according to claim 1, wherein an output cable is connected to a connection between the output terminal and a positive output terminal of a battery adjacent to the output terminal.