JPH10285819A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger flexibly adapted to the ratings of wiring accessories such as a plug socket without making many modifications to the conventional structure, in a charger which is mounted on an electric vehicle together with a battery for charging the battery. SOLUTION: This system is provided with a voltage converter 11 which converts the voltage of the power input from outside, generates DC power of a desired voltage, and then supplies the generated DC power to a battery, a voltage characteristic setting means 12 which sets the voltage characteristic so that the DC power supplied to the battery may be the specified maximum value or below, and a maximum value supplying means 13 which receives an instruction from outside and supplies the preliminarily determined maximum value to the voltage characteristic setting means 12 according to the instruction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device mounted on an electric vehicle together with a storage battery and charging the storage battery.

[0002]

2. Description of the Related Art Charging of a storage battery mounted on an electric vehicle requires a large amount of energy as compared with home electric equipment.
This is performed by taking in power from an outlet (hereinafter, referred to as a "200 V outlet") to which the voltage is distributed.

FIG. 4 is a diagram showing a configuration example of a charging device mounted on a conventional electric vehicle. In the figure, an output of a rectifier circuit 42 is connected to an input of a voltage conversion circuit 41, and one of two outputs of the voltage conversion circuit 41 is connected to one end of a storage battery (not shown), and the other is connected through a resistor 44 to the other end. Connected to the other end of the storage battery. One terminal of the resistor 44 directly connected to the voltage conversion circuit 41 is connected via a resistor 45 to the inverting input of a differential amplifier 46, and the other terminal of the resistor 44 is connected via a resistor 47 to a differential terminal. It is connected to the non-inverting input of the operational amplifier 46. The output of the differential amplifier 46 is connected to the non-inverting input of the differential amplifier 48, and the output of the differential amplifier 48 is connected to the control input of the voltage conversion circuit 41. The inverting input of the differential amplifier 48 is connected to the anode of a reference voltage source 49, and the cathode of the reference voltage source 49 is grounded.

[0004] Since the configuration of the voltage conversion circuit 41 is known, a detailed description thereof will be omitted. In the conventional example of the above configuration, when the storage battery is charged, the rectifier circuit 42
Connected to a 00V outlet. The rectification circuit 42 converts AC power supplied from a commercial power supply into DC power, and the voltage conversion circuit 41 performs PWM control in accordance with a control signal input from a differential amplifier 48 to a control terminal, as described later, to perform rectification. The storage battery is charged by converting the DC power supplied from the circuit 42 into DC power having a voltage suitable for the storage battery.

[0005] During this charging period, the voltage characteristics of the voltage conversion circuit 41 are set in the following procedure. Resistors 44, 4
5, 47 and the differential amplifier 46 convert the value of the charging current I flowing through the storage battery into a voltage. The differential amplifier 48 converts the voltage to a reference voltage VRE provided by a reference voltage source 49.
The value obtained by subtracting F1 is used as a control signal to be input to the voltage conversion circuit 41.

FIG. 5 shows a voltage conversion circuit 4 according to a control signal.
FIG. 3 is a diagram illustrating a voltage characteristic set to 1. When the control signal has a negative value, the voltage conversion circuit 41 holds the value of the charging voltage V at Vm, assuming that the charging current I falls below the threshold value Is corresponding to the reference voltage VREF1 (FIG. 5).
(1)), when the control signal is a positive value, the charging current I is considered to exceed the threshold value Is, and the charging voltage V is sharply reduced with respect to the charging current I (FIG. 5 (2)). .
That is, the DC power (V * I) supplied to the storage battery by the voltage conversion circuit 41 is always suppressed to the maximum value represented by (Vm * Is) (hereinafter, the voltage conversion circuit 41 is connected to the storage battery as described above). The supplied DC power (V * I) is simply referred to as “charging power”.)

Therefore, the maximum value of the input power of the charging device (hereinafter, referred to as “maximum input power”) determined by both the charging power and the efficiency of the conversion performed by the rectifier circuit 42 and the voltage conversion circuit 41 is charged. This value is unique to the device.
Generally, the maximum input power of a charging device mounted on an electric vehicle is a large value such as 4 KVA. When such a charging device is connected to a 200 V outlet, a maximum current of 20 A flows through the input terminal a of the rectifier circuit 42, but the rated current value specified by the Japanese standard is applied to the 200 V outlet. Is 30 A, so that sufficiently safe charging is performed.

[0008]

If the remaining amount of the storage battery becomes low while the electric vehicle is traveling in an area where a 200 V outlet is not installed, the electric vehicle is installed in a general household. , 100 V voltage is distributed to the outlet (hereinafter, referred to as “100 V outlet”).

When a conventional charging device is connected to a 100 V outlet, a current of at most 40 A flows through point a to take in the same power. However, since the rated current of the 100 V outlet is about 15 A, this charging is very dangerous and is not actually performed. Therefore,
The traveling range of the electric vehicle was limited to an area where 200 V outlets were widespread.

[0010] It is an object of the present invention to provide a charging apparatus that can flexibly adapt to the rating of a wiring device such as an outlet without significantly changing a conventional configuration.

[0011]

FIG. 1 is a block diagram showing the principle of the first and second aspects of the present invention.

According to the first aspect of the present invention, voltage conversion processing is performed on input power input from the outside to generate DC power of a desired voltage, and the generated DC power is supplied to a storage battery. Means 11 and voltage conversion means 11
A voltage characteristic setting means 12 for setting a voltage characteristic such that the DC power supplied to the storage battery is equal to or less than a given maximum value;
A maximum value assigning means for receiving a command given from the outside and for giving a predetermined maximum value to the voltage characteristic setting means in correspondence with the command is provided.

According to a second aspect of the present invention, a DC conversion of a desired voltage is generated by applying a voltage conversion process to input power input from the outside, and the generated DC power is supplied to a storage battery. Means 11 and voltage conversion means 11
A voltage characteristic setting means 12 for setting a voltage characteristic such that the DC power supplied to the storage battery is equal to or less than a given maximum value;
And a maximum value assigning means for monitoring a voltage of an input terminal of the voltage converting means and applying a predetermined function of the monitored voltage as a maximum value to the voltage characteristic setting means.

(Operation) In the charging device according to the first aspect of the present invention, the voltage conversion means 11 generates DC power of a desired voltage by performing voltage conversion processing on input power input from the outside. Since the DC power is supplied to the storage battery, the storage battery is charged. The voltage characteristic setting means 12 sets, in the voltage conversion means 11, a voltage characteristic in which the DC power supplied to the storage battery is equal to or less than the given maximum value. An upper limit is set for power DC power. further,
Since the maximum value applying means 13 sets the maximum value applied to the voltage characteristic setting means 12 to a predetermined value according to an instruction given from the outside, it is possible to change the upper limit of the DC power. Become.

Here, the value of the input power input to the voltage conversion means 11 changes according to the value of the DC power. Therefore, it is possible to set the upper limit of the input power to a desired value by determining in advance the value to be set as the upper limit of the DC power by the maximum value applying means 13 in association with the content of the instruction. In the charging device according to the second aspect of the present invention, a maximum value providing unit is provided instead of the maximum value providing unit in the charging device according to the first aspect. The maximum value providing means 14 monitors the voltage of the input terminal of the voltage converting means 11 and
The maximum value given to 2 is a function of that voltage.

Therefore, by determining the function in advance, the upper limit of the input power that changes according to the DC power is
It is possible to automatically set a desired value corresponding to the voltage.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a diagram showing the configuration of the first and second embodiments. In the figure, components having the same functions and configurations as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted here. The difference between the first embodiment and the conventional example is that the inverting input of the differential amplifier 48 is connected to the common contact of the single-pole / double-throw switch 31, and both contacts of the switch 31 are connected to the reference voltage source 49, respectively. 32 at a point grounded.

This embodiment corresponds to claim 1 shown in FIG. 1, and the voltage conversion circuit 41 corresponds to the voltage conversion means 11, and includes the voltage conversion circuit 41, the resistors 44, 45, 47, and the differential amplifier. The whole of 46 and 48 corresponds to the voltage characteristic setting means 12, and the whole of the switch 31 and the reference voltage sources 32 and 49 correspond to the maximum value giving means 13. FIG. 3 is a diagram illustrating voltage characteristics set in the voltage conversion circuit 41 in the present embodiment.

The operation of this embodiment will be described below with reference to FIGS. In the present embodiment, the outlet of the electric vehicle is identified by the driver of the electric vehicle, and when it is confirmed that the outlet is of the 200 V type, the switch 3 is turned on.
By connecting the input terminal of the rectifier circuit 42 to an outlet after connecting one common contact to the reference voltage source 49, charging can be performed with the same voltage characteristics as the conventional example (FIG. 3 (1)).

On the other hand, when it is confirmed that the outlet is of the 100 V type, the reference contact point of the switch 31 is connected to the reference voltage source 32, so that the voltage characteristics with the threshold value It different from the conventional example (FIG. 3 (2)) can be set. Hereinafter, the voltage provided by the reference voltage source 32 and the reference voltage VREF2 will be described. In general, the charging power (V * I) with respect to the input power P is represented by the following equation: P = μ * (V * I) (1), depending on the conversion efficiency μ between the rectifier circuit 42 and the voltage conversion circuit 41. Given by In the equation (1), the input power when the charging power is the maximum is the maximum input power Pm, so that the following equation holds: Pm = μ * (Vm * It) (2)

Further, the threshold value It of the charging current set by the reference voltage VREF2 is determined by the gain G of the differential amplifier 46 determined by the resistors 44, 45 and 47, VREF2 = G * It (3) ).

Therefore, the reference voltage VREF2 is given by the equation (3)
From equation (2), a predetermined voltage conversion efficiency μ,
A function of the maximum input power Pm using the gain G and the charging voltage Vm, VREF2 = (μ * G / Vm) * Pm (4) Therefore, the value of the reference voltage VREF2 is set to 1
Rating of 00V outlet (rated current value is 15A)
To accommodate the maximum input power P based on equation (4).
It is set in advance so that m becomes 1.5 KVA or less.

That is, if the above reference voltage VREF2 is applied when the outlet is a 100 V system, the maximum input power Pm can be suppressed to 1.5 KVA or less, so that the current flowing to the input terminal a of the rectifier circuit 42 is It will be less than the rated value of the outlet. Therefore, in the present embodiment, the safety of charging is ensured by switching the switch 31 irrespective of whether the outlet via the power supply is a 100 V system or a 200 V system.

In the second embodiment, the identification circuit 33 is provided between the output terminal of the rectifier circuit 42 and the switch 31 in the first embodiment. This embodiment corresponds to claim 2, wherein the identification circuit 33 and the switch 3
1. The entirety of the reference voltage sources 49 and 32 is
Corresponds to 4. The difference between this embodiment and the first embodiment is that the switching of the switch 31 is performed by the identification circuit 33.

When the electric vehicle is connected to the outlet,
The voltage at the output terminal of the rectifier circuit 42 takes a value corresponding to the voltage value distributed to the outlet. The identification circuit 33 monitors the voltage of the output terminal, and if the value is 100 V or 200 V in advance.
It is determined whether the value exceeds a reference value set to a value between. When the value exceeds the reference value, the identification circuit 33 determines that the outlet is a 200 V system, and connects the common contact of the switch 31 to the reference voltage source 49.

If the identification circuit 33 determines that the outlet is lower than the reference value, the identification circuit 33 determines that the outlet is a 100 V system, and connects the common contact of the switch 31 to the reference voltage source 32. Therefore, in this embodiment, safe charging adapted to the outlet is automatically performed.

In the above-described first embodiment, the switch 31 is provided. The switch 31 may be replaced with any man-machine interface as long as the same switching is performed according to an external input. Is also good. In the second embodiment described above, the identification circuit 33,
Instead of the switch 31 and the reference voltage sources 49 and 32, a circuit may be formed that obtains the voltage value of the output terminal of the rectifier circuit 42 and directly applies a value given as a function of the voltage value to the inverting input of the operational amplifier. Good. In general, the rated power of the outlet is a value proportional to the square of the voltage to be distributed, so that the maximum input power of the device is less than the rated value.
By setting the function based on the proportionality constant and the above equation (4), charging suitable for various outlets can be performed.

In each of the above-described embodiments, the state where the charging power is maximized is detected by monitoring the charging current.
The monitoring may be performed by monitoring the product of the charging voltage and the charging current. In each of the above-described embodiments, two different reference voltage sources are provided to accommodate two outlets having different rated currents. However, when there is a possibility that a large number of outlets having different rated currents may be used, Reference voltage source is 3
More than one may be provided.

In each of the above-described embodiments, the reference voltage is varied by the combination of the switch 31 and the reference voltage sources 49 and 32. For example, the value of the reference voltage to be set is stored in association with the input value. It may be realized by a processor having a memory that performs the processing. In each of the embodiments described above,
Although the compensation of the value of the charging voltage V is performed by the voltage conversion circuit 41, the compensation may be performed by changing the rectification method performed by the rectification circuit 42 according to the applied voltage. In such a case, the change in the voltage at the output terminal of the rectifier circuit 42 is small with respect to the change in the input voltage, so that the voltage monitoring should be performed with sufficient accuracy to detect the small change. Alternatively, the point to be monitored or the voltage to be monitored may be replaced with the input terminal of the rectifier circuit 42.

In each of the above embodiments, an outlet to which a constant voltage is distributed has been described as a wiring device. However, the wiring device may be any device that forms a power supply path such as an electric wire or a plug. May be. Further, in each of the above-described embodiments, the voltage characteristic of the charging device is set to the drooping characteristic, but the voltage characteristic may be set to any characteristic as long as the maximum value of the power is determined by the control signal. .

[0032]

As described above, according to the first aspect of the present invention, the maximum value of the charging power given to the storage battery is set to a predetermined value in accordance with an externally given instruction. Can be set to a desired value. According to the second aspect of the present invention, since the maximum value of the charging power supplied to the storage battery is set as a function of the input voltage, the upper limit of the input power input for charging is set to a desired value corresponding to the voltage. Can be set automatically.

Therefore, according to the present invention, even if the ratings of the wiring devices that can be connected at the time of charging are various, safety can be ensured by performing charging according to each rating. Further, in the electric vehicle to which the present invention is applied, charging can be performed in an area where only a 100 V-type outlet is installed, with almost no change in the basic configuration. Therefore, the traveling range of the electric vehicle is expanded at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of the present invention.

FIG. 2 is a diagram illustrating a configuration of first and second embodiments.

FIG. 3 is a diagram illustrating voltage characteristics set in a voltage conversion circuit 41 in the present embodiment.

FIG. 4 is a diagram illustrating a configuration example of a charging device mounted on a conventional electric vehicle.

FIG. 5 is a diagram showing voltage characteristics set in a voltage conversion circuit 41 according to a control signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Voltage conversion means 12 Voltage characteristic setting means 13, 14 Maximum value provision means 46, 48 Differential amplifier 31 Switch 32, 49 Reference voltage source 33 Identification circuit 41 Voltage conversion circuit 42 Rectification circuit 44, 45, 47 Resistor

Claims (2)

[Claims] 1. A voltage conversion means for generating DC power of a desired voltage by applying voltage conversion processing to input power input from the outside and supplying the generated DC power to a storage battery; A voltage characteristic setting means for setting a voltage characteristic such that the DC power supplied to the storage battery is equal to or less than a given maximum value; receiving a command given from the outside; And a maximum value providing means for providing a value to the voltage characteristic setting means. 2. A voltage conversion unit that generates DC power of a desired voltage by performing voltage conversion processing on input power input from the outside, and supplies the generated DC power to a storage battery, and the voltage conversion unit. A voltage characteristic setting means for setting a voltage characteristic at which the DC power supplied to the storage battery is equal to or less than a given maximum value; and monitoring a voltage at an input terminal of the voltage conversion means, and determining the monitored voltage in advance. And a maximum value providing means for providing the obtained function as a maximum value to the voltage characteristic setting means.