JPH10271682A - Control method of power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make use of a power supply to which various loads are connected economically without complexing wirings and control systems. SOLUTION: The total load power of a power supply device to which at least types of loads which stop operation by the detection of the decline of an input voltage and restore operation automatically by the recovery of the input voltage among various types of loads is consistently monitored. If the total load power exceeds a rated capacity, the output voltage of the power supply device is temporarily lowered to a voltage which can be detected by the above mentioned types of loads as shown in Fig. (e) to stop the loads temporarily. With this constitution, the total load power supplied by the power supply can be reduced without complexing wirings and control systems.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having various and various load devices, the control of which is difficult to control, particularly, the detection of a drop in input voltage, the stop of the power supply device, and the restart (automatic restart) by the return of the input voltage. The present invention relates to a control method in a case where a load device of a type that performs a return is provided.

[0002]

2. Description of the Related Art FIG. 2 shows a configuration example of a power supply device and load devices. In the figure, a load device 3A of a type (type) that is continuously turned on and a load device 3A that is continuously turned on are supplied to a power supply device 1 that is, for example, a semiconductor power converter, that converts an input voltage Vin into a constant output voltage Vout. However, there are various types of load equipment 3B, such as a type of load equipment 3B that detects a drop in input voltage and stops and restarts (automatic return) upon the return of the input voltage, and a type of load equipment 3C that is turned on only in special cases. , Various load devices are connected, and the power supply device 1 supplies power thereto.

Here, for example, assuming an auxiliary power supply device for a vehicle, a load device 3A is a lighting device such as a fluorescent lamp, a load device 3B is a motor load such as an air conditioner, and a load device 3C.
Means a device that works when the air pressure drops, such as a compressor. The rated capacity of a power supply device that supplies power to these devices needs to be satisfied in all use states of the device (train). Therefore, for example, when a plurality of power supply devices are used in combination, and one of the power supply devices fails, the other power supply device supplies power to the load of the failed power supply device. When the amount becomes the maximum load in the operation of the equipment,
This will determine the rated capacity of the device.

[0004] This and the conventional control method together with FIG.
This will be described with reference to FIG. That is, the control device 2 shown in FIG.
FIG. 3E shows that the output voltage Vout of the power supply device 1 detected via the voltage detector 5 such as a transformer is constant.
In general, control is performed as follows. Therefore, the load amount of the load 3A in (a) is W1, the load amount of the load 3B in (b) is W2, and the load amount of the load 3C in (c) is W.
If it is 3, the required capacity of the power supply device 1 is W (= W1 + W2 + W3) as shown in FIG. That is, the load 3B is of a type that detects a drop in the input voltage and stops and restarts when the input voltage returns, but conventionally, the load 3B is controlled so that the output voltage Vout of the power supply device 1 becomes constant as shown in (e). Therefore, the load 3B continues the operation without stopping as in (b).

[0005]

In the conventional control method as described above, a rated output capacity (W) that satisfies the load under special conditions is required, and as a result, the apparatus becomes large and the cost increases. Problem. Therefore, for example, under special conditions, it is conceivable to perform control such as stopping a part of the load. However, for that purpose, a control signal for the load device is required, and there is a problem that wiring and control become complicated. . Therefore, an object of the present invention is to eliminate the need for such special wiring and to not complicate the control.

[0006]

According to the first aspect of the present invention, there is provided a load device of the type which stops at least when a decrease in input voltage is detected and automatically recovers when the input voltage returns. The total load of the connected power supply is constantly monitored, and when this exceeds the rated capacity of the power supply, the output voltage of the power supply is temporarily reduced to a voltage value that can be detected by the load device of the type described above. In this case, the load device is temporarily stopped. According to the first aspect of the present invention, when changing the voltage of the power supply device, control can be performed so that the rate of change is constant (the second aspect of the invention).

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram for explaining an embodiment of the present invention. In this example, detectors 4 and 5
The controller 2 constantly calculates the load amount from the voltage and current detected by the control unit 2 and monitors whether the load amount exceeds the rated output capacity of the power supply device 1. Then, when it is detected that this load amount exceeds the rated output capacity of the power supply device 1 (see time t1 in the figure), the control device 2 adjusts the output voltage of the power supply device 1 to a voltage level that can be detected by the load device 3B. By temporarily lowering the load device 3B as shown in FIG. 1 (e) and thereby temporarily stopping the load device 3B as shown in FIG. 1 (b), the total load does not exceed the rated output capacity. Suppress.

As a result, the required capacity W of the power supply 1 is
As shown in (d), the sum of the load amount W1 of the load device 3A and the load amount W3 of the load device 3C is obtained, and it is possible to reduce the load (W2) by the load device 3B as compared with the conventional example.
After a lapse of a predetermined time (see time t2), FIG.
The voltage value is returned to a constant value as shown in (e). Therefore, the load device 3B is restarted (automatically returns) as shown in FIG.

By the way, when the output voltage of the power supply device 1 is AC, if the output voltage is rapidly changed, the output voltage is distorted,
When a frequency component near 10 Hz is included, a so-called flicker phenomenon occurs in which the fluorescent lamp as a load flickers. Also, when the output voltage is suddenly increased when the output voltage is returned to the rated voltage, the exciting current enters the transformer or the motor as the load. In order to suppress these phenomena, as shown in FIG. 1E, when the output voltage is increased or decreased, the voltage is controlled so that the rate of change (ΔV / Δt) is constant. For this purpose, a function generator or the like for generating a voltage command as shown in FIG. At this time, the overall load of the power supply 1 temporarily changes largely as shown in FIG. 1D, but since the time is short, it hardly affects the required capacity of the device.

Although the above description has been made mainly on the assumption of an auxiliary power supply device for a vehicle, it goes without saying that the present invention can be similarly applied to a similar power supply device.

[0011]

According to the present invention, the output voltage of the power supply is reduced only in a special case, and a part of the load is temporarily stopped, so that the rated output capacity required for the power supply is reduced. This has the advantage that the size, weight and cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for describing an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a connection relationship between a power supply device and a load device.

FIG. 3 is a waveform chart for explaining a conventional control method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply device, 2 ... Control device, 3A, 3B, 3C ... Load equipment, 4 ... Current detector, 5 ... Voltage detector, W ... Required load capacity.

Continuation of the front page (72) Inventor Kazuyuki Yoda 1-1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fuji Electric Co., Ltd.

Claims (2)

[Claims] 1. A power supply device to which at least a drop in input voltage is detected and stopped, and a load device of a type that automatically recovers when the input voltage is restored is continuously monitored, and this is the rated capacity of the power supply device. A power supply device, the output voltage of the power supply device is temporarily reduced to a voltage value that can be detected by the load device of the type, and the load device is temporarily stopped. 2. The method according to claim 1, wherein when changing the voltage of the power supply, control is performed so that the rate of change is constant.