JP2000232737A - Charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop inverter control with reliability even if there is no zerocrossing signal or if there is a zero-crossing but a detected value is equal to or below a specified value, by stopping charging. SOLUTION: If a zero-crossing signal is detected, a charging current (current sensor detection value IB) is compared with a control target value IBref. The current sensor detection value IB is PWM-controlled through a control circuit 18. If power is externally supplied, therefore, the actual current value and the control target value Ibref are virtually equal to each other, and it is judged that charging is normally performed. If no zero-crossing signal is detected, it is judged that there is no supply of external power, and control on the inverter 14 is stopped and a relay 24 is also interrupted. There are cases where a zero-crossing signal is produced by the circulating power from other circuits. If there is no supply of external power, however, no current is passed by controlling the inverter 14, and the actual current value and the control target value Ibref are not virtually equal to each other. At this time, control is exercised so that charging is in a stop, and operation is kept in standby state until charging is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a secondary battery, and more particularly to a charging device for charging a secondary battery from an AC power supply using an inverter for converting the power of the secondary battery into AC power. .

[0002]

2. Description of the Related Art There is known an electric power supply device which converts DC power supplied from a secondary battery into AC power by an inverter and supplies the AC power. There is also known a charging device that charges the secondary battery from an external AC power supply such as a commercial power supply using the inverter.

For example, in an electric vehicle, electric power from a secondary battery mounted on a vehicle is converted into AC power by an inverter, and this is supplied to a motor for driving a vehicle. When the vehicle is not in use, a plug on the vehicle is connected to an outlet provided at a charging station or the like, from which the secondary battery is charged with electric power. The external power supply at this time is
It is a commercial power supply of 100 V or 200 V, and is an AC power supply. This AC power is converted into DC using the inverter for supplying power, and the secondary battery is charged. At this time, in order to make the phases of the supplied AC power and the charging current uniform, that is, to set the power factor to 1, the inverter is controlled based on a zero-cross signal serving as a reference of the phase of the voltage of the commercial power supply. The zero-cross signal is a signal that switches between a high level and a low level every time the voltage of the commercial power supply becomes 0V. This signal is supplied to the controller of the inverter, and on / off of the elements of the inverter is controlled based on this signal, and the secondary battery is charged.

When the plug on the vehicle side is unplugged from the outlet,
There is no zero-cross signal generated corresponding to the commercial power supply voltage. The controller detects this, determines that the plug has been removed, and stops controlling the inverter.

[0005]

In the above-described charging device, there is a problem that even when the plug is unplugged, a zero-cross signal is output due to a sneak path from another circuit. That is, there is a problem that the control of the inverter is executed even though the plug is disconnected.

The present invention has been made to solve the above-described problem, and has as its object to surely stop control of an inverter when charging power is not supplied.

[0007]

In order to solve the above-mentioned problems, a charging apparatus according to the present invention uses an inverter that converts the power of a secondary battery into AC power and supplies the AC power to an AC motor, A charging device for charging the secondary battery with power from the battery, and a current sensor for detecting a current input to the secondary battery during charging, and determining that a detection value of the current sensor is a predetermined value And a stop unit that stops charging when the determination unit determines that the detected value is not the predetermined value.

[0008]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of the present embodiment. The present embodiment is mounted on an electric vehicle, and is a motor 10 that drives a vehicle, an inverter 14 that converts electric power of a secondary battery 12 into a three-phase alternating current and supplies the three-phase alternating current to the drive motor 10, and an inverter 14
And a control circuit 18 for controlling the transistors.
These configurations are conventionally employed as drive system circuits for electric vehicles.

Further, in order to charge the secondary battery 12 with electric power from an external power supply, particularly, in this embodiment, the following configuration is provided. It has a plug 20 for connection to an outlet of a 100 V commercial power supply. One terminal of the plug is connected to a neutral point of the motor 10 via a breaker 22 and a relay 24, and the other terminal is connected to a positive electrode of the secondary battery 12. And a diode 26a for the negative electrode,
26b. Transistors 28a, 28b, 30a, 30b, 3 included in inverter 14
The base terminals of 2a and 32b are connected to the control signal terminal 34 of the control circuit 18, but the control signal lines are omitted in FIG. Further, the transistors 28a to 28a-3
2b and diodes 36a, 36b, 38
a, 38b, 40a and 40b are provided.

Further, a zero-cross signal generator 42 and a current sensor 44 are provided to detect the state of power supply from an external power supply and the state of charge to the secondary battery during charging. The zero cross signal generator 42 is connected to a power supply line from the plug 20. The zero-cross signal is a signal that switches between a high level and a low level each time the voltage of the AC commercial power supply becomes 0 V, and serves as a reference for the phase of the voltage of the commercial power supply. At the time of charging, the control circuit 1
8 is the inverter 1 based on the zero-cross signal.
4 are controlled so that the phases of the voltage and the current are aligned, that is, the power factor is 1. The current sensor 44 is a current for detecting a current flowing through the secondary battery 12, and the detected value IB is sent to the control circuit 18.

When the electric vehicle is running, the main switch 46
a, 46b are connected, and the DC power from the secondary battery 12 is converted into three-phase AC by the inverter 14,
0 is supplied. Further, during braking, the inverter 14 is controlled so that the electric power generated by the motor 10 is regenerated to the secondary battery 12. The inrush limit switch 50 connected in series with the resistor 48 and arranged in parallel with the main switch 46a is for gradually supplying electric charge to the capacitor 52 at the time of starting. And the rush limit switch 50
Is opened when a predetermined amount of charge is stored in the capacitor 52, and the main switch 46a is connected.

At the time of charging, the plug 20 is connected to an outlet of a commercial power supply. The operation of the inverter at the time of charging will be described using the transistors 32a and 32b as an example. The control circuit 18 refers to the zero cross signal to determine whether the voltage at the neutral point of the motor 10 connected to the commercial power supply is positive or negative. When the voltage at the neutral point is positive, the transistor 32b is controlled to repeat on and off, and the transistor 32a is controlled to be off. When the transistor 32b is turned off from on, the voltage is boosted by the field coil of the motor, a current flows through the diodes 40a and 26b, and the secondary battery 12 is charged. On the contrary, when the voltage at the neutral point becomes negative, the transistor 32a is turned on and off, and the transistor 32b
Is controlled off. When the transistor 32a is turned off from on, the voltage is boosted by the field coil, a current flows through the diodes 26a and 40b, and the secondary battery 12 is charged. The other phase transistors 28a, 28b, 30a,
Similar control is performed for 30b, and charging is performed. The on / off control of each transistor is performed by PWM.
(Pulse width modulation), whereby the charging current is controlled.

When power supply from the commercial power supply stops,
The control circuit stops the control of the inverter. The stop of the power supply is determined according to the flow shown in FIG. First, it is determined whether there is a zero cross signal (S
100). When the zero cross signal is detected, the detection value IB of the current sensor is compared with the control target current value IBref (S102). The current to be charged, that is, the detection value IB of the current sensor is controlled by the PWM control of the control circuit 18. Therefore, if power is normally supplied from the outside, the actual current value IB and the control target value IB are controlled. IBref will be substantially equal. If these are equal, it can be determined that the charging is performed normally, and this flow ends.

On the other hand, if a zero cross signal is not detected in step S100, a situation in which power is not supplied from the outside, for example, a situation in which the plug 20 is disconnected is considered. In this case, control of the inverter 14 is stopped ( S1
04). Further, the relay 24 is shut off (S104).
Further, the zero-cross signal may be generated by power sneaking from another circuit or the like. For example, there is a case where the output is performed even when the plug 20 is disconnected and power is not supplied from the outside. Even in such a state, in order to stop the control of the inverter 14, the actual current value IB and the control target value IBref are compared in step S102. If power is not supplied from the outside, no current flows even if the inverter 14 is controlled, so that the actual current value IB and the control target value IBref are not substantially equal. When this situation is determined, the process moves to step S104. Step S1
When 04 is completed, the charging is stopped, and the process waits until the charging starts (S106), and the flow ends.

The control circuit 18 performs an operation according to step S102, thereby functioning as a judging means for judging that the detected value IB of the current sensor has reached a predetermined value. When the detection value IB of the current sensor becomes substantially 0, it can be determined that there is no external power supply. Further, the control circuit 18 functions as a stop unit that stops charging by performing the operation according to step S104.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of the present embodiment.

FIG. 2 is a flowchart for determining a state where power is not supplied from the outside.

[Explanation of symbols]

10 motor, 12 rechargeable battery, 14 inverter, 1
8 control circuit, 20 plugs, 24 relays, 42 zero cross signal generator, 44 current sensor.

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[Procedure amendment]

[Submission date] March 8, 2000 (200.3.8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In order to solve the above-mentioned problems, a charging apparatus according to the present invention uses an inverter that converts the power of a secondary battery into AC power and supplies the AC power to an AC motor, A charging device for charging the secondary battery with electric power from the AC power supplied from a commercial power supply.
Each time the voltage goes to zero, the high and low levels are switched.
Signal generating means for outputting a zero-cross signal
First determining means for determining the presence or absence of a zero-cross signal;
A current sensor that detects a current input to the secondary battery at the time of charging, a second determination unit that determines that a detection value of the current sensor is a predetermined value, and a first determination unit.
When there is no zero cross signal, and when the first determination
Is a zero-cross signal by the step is present, and by the second determination means, the detection value has a a stop means for stopping the charging at, in the case where it is determined that not the predetermined value.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryoji Oki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hidenobu Watanabe 2-1-1 Taoyuan, Ikeda-shi, Osaka Daihatsu Kogyo Co., Ltd. In-house F term (reference) 5G003 AA01 BA01 CA04 DA07 DA15 FA06 GB06 5H007 BB06 CA01 CB05 CC01 CC09 DC02 DC05 FA14 FA19 GA03 GA08 5H115 PA08 PG04 PI02 PU08 PV09 PV23

Claims (1)

[Claims] 1. A charging device for charging an electric power from an external AC power supply to the secondary battery by using an inverter for converting the electric power of the secondary battery to AC power and supplying the AC power to an AC motor, wherein the secondary battery is charged at the time of charging. A current sensor that detects a current input to the current sensor; a determination unit that determines that a detection value of the current sensor is a predetermined value; and a determination that the detection value is not a predetermined value. A stopping means for stopping charging when the charging is performed;
A charging device having: