JP2000122731A - Current power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a current power unit which is fast and inexpensive by connecting a current power source, a voltage power source, and a load device in series. SOLUTION: The current power source 1, voltage power source 2, and load device 3 are connected in series. The voltage power source 2 need not operate fast and may operate slow and the voltage value need not be variable and may be fixed under certain conditions. The total of the voltage value of a variable voltage power source in the current power source 1 and the voltage value of a voltage power source 2 is the value of the voltage to the load device 3. Therefore, the voltage value of the voltage power source in the current power source 1 can be lowered by the voltage value of the voltage power source 2 and the power capacity of the current power source 1 which is fast and expensive can be decreased by the quantity, so that an inexpensive device is obtained. Thus, the current power unit which is fast and inexpensive can be obtained by combining the small-capacity fast current power source 1 and slow inexpensive voltage power source 2 together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an inexpensive current power supply device capable of controlling the current of an inductive load device at high speed, and more specifically, a coil drive for a magnetic bearing device, a magnetic levitation device and the like. It is effective when used.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a circuit for driving an inductive load from a conventional current power supply. In FIG. 3, reference numeral 1 denotes a DC current power supply, 3 denotes an inductive load device, and It comprises a reactance component 31 and a resistance component 32. In the following, a magnetic bearing device will be described as an example,
Of course, the present invention can be applied to other devices.
The current value of the current power supply 1 is controlled by a bearing gap detector and a gap constant control device (not shown), and the current power supply 1 drives the load device 3 which is a bearing drive coil to keep the bearing gap constant. Usually, the gap of the bearing changes at a high speed due to vibration or impact of the shaft. Therefore, although the current of the load device 3 is also an inductive load, it is necessary to control the current at a high speed by the output of the gap detector or the like.

Generally, what can be prepared as a DC power supply is
It is a voltage source created by rectifying a single-phase or three-phase AC power supply that is distributed to batteries, homes, and businesses. To realize the current power supply 1, there is a method of connecting a relatively high-inductance reactor in series with the voltage power supply. However, this cannot change the current at a high speed. It cannot be used for applications that need to be performed.

FIG. 4 shows an example of a conventional circuit for realizing the high-speed current power supply 1, and those having the same numbers as those in FIG. In FIG. 4, 11 is a current setting signal, 12 is a current detection signal of the load current detector 16, 13 is a subtractor that outputs a difference between them (current setting signal 11 −current detection signal 12), and 14 is a subtractor 13 is a voltage controller that amplifies the output of the power supply 13 and adjusts the voltage value of the variable voltage power supply 15. By these devices, the current of the current detector 16, that is, the current of the load device 3 is controlled so as to match the current setting signal 11. The current setting signal 11 is a current power supply 1 (not shown in detail).
Or an external current setting signal. The circuit of the current power supply 1 according to 11 to 16 operates as a current power supply whose output current matches the current setting signal 11. A power supply device having a function having the configuration shown in FIG. 4 is a general type of various types of constant voltage / constant current DC power supply devices that can be operated as a voltage power supply and are commercially available from various companies.

Assuming that the current value of the current power supply 1 in FIG. 3 is i, the inductance of the reactance component 31 in the load device 3 is L, and the resistance value of the resistance component 32 is R, the voltage vL across the load device 3 is vL = Ldi / dt + Ri (1) Therefore, the voltage value of the variable voltage power supply 15 shown in FIG. The current change rate is regulated by the first term on the right side, and is desirably as large as possible in order to perform high-speed current control.

[0006]

Now, specifically, i = 2
Assuming that 0A and R = 1.6Ω, the voltage value of the variable voltage power supply 15 is constantly 1.6Ω × 20A =
32V is required, and transiently a value obtained by adding the first term is required. The higher the value of the first term, the faster the current control operation becomes possible. As the current power supply 1, as an example of a commercially available device, a high-speed 0-60V, 0-20A constant voltage / constant current DC power supply IPS060-20, which is sold by Takasago Machinery Works, Ltd., is set to a current mode. However, it is very expensive as a 1.2 kW power supply device. (References "'97 /
DC / AC / Power Catalog ”). By the way, GP060-20R of the same rating which is not high-speed specification is considerably cheaper than high-speed one, and high-speed power supply is very expensive. The present invention has been made in view of the above points, and an object of the present invention is to provide a high-speed and inexpensive current power supply device.

[0007]

[Means for Solving the Problems] That is, means for achieving the object are as follows: A current power supply device according to claim 1, wherein a current power supply, a voltage power supply, and a load device are connected in series.

[0008] 2. The voltage detector according to claim 2, wherein the first voltage power supply, the second voltage power supply, and the load device are connected in series, and a current detector for detecting a current of the load device and a voltage detector for detecting a voltage of the first voltage power supply. Wherein the voltage of the first voltage power supply is controlled by the output of the current detector, and the voltage of the second voltage power supply is controlled by the output of the voltage detector. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0009]

FIG. 1 shows an embodiment of a high-speed current power supply according to claim 1 of the present invention, wherein the same reference numerals as those in FIG. 3 denote the same parts, and FIG.
Reference numeral 2 denotes a voltage power supply, which does not need to operate at high speed but may be a very low-speed general one. The voltage value does not need to be variable under certain conditions and may be fixed. FIG.
As shown in FIG. 4, as shown in FIG.
The voltage value of the variable voltage power supply 15 shown in FIG.
It is sufficient that the sum of the voltage values is equal to the voltage vL of the expression (1).
5 can be reduced by the voltage value of the voltage source 2 in FIG. 1, and the power capacity of the high-speed and expensive current power supply 1 can be reduced by that amount, and an inexpensive device can be obtained.

Assuming that 20 A flows through the load device 3 in the same manner as in the above-described specific example, and assuming that there is almost no load fluctuation, the current power supply 1 is, as in the above-described example, based on the IPS060-20 manufactured by Takasago Seisakusho Co., Ltd. Inexpensive, 16V20
A, High-speed constant voltage / constant current DC power supply IPS016-2
0 is the above-mentioned 60 V2
0A rated GP060-20R can be used. Here, even if the total price of both is combined, one high-speed current power supply IPS
It can be much cheaper than using 060-20. The power supply voltage capability of IPS060-20 is 6
0V, but IPS016-20 which is a high-speed current power supply
And the total power supply voltage capability of the low-speed voltage supply GP060-20R is 16 + 60 = 76V, and there is ample room in this respect as well. Further, the low-speed voltage power supply GP060-20R has a variable voltage value, but if it has an appropriate fixed voltage value (60-16 = 44 V or more), this may be used, and the cost is lower.

Since the operation is essentially based on the voltage power supply even if it is a current power supply, as apparent from the equation (1), this voltage capability is applied to the load device of the second term on the right side. A voltage generated when a predetermined current flows and a voltage to be applied to an inductance component of a load device for realizing the high-speed current control of the first term are required. According to the device of FIG. It has a function to secure this voltage capability.

In the circuit shown in FIG. 1, it is assumed that there is almost no change in the load or the set current value, but when there is such a change, the voltage value of the voltage power supply 2 can be changed.
It is necessary to pay attention to the voltage capability of the current power supply 1 and the like. If the voltage range of the internal voltage power supply 15 of the current power supply 1 is 0 to 16
V, the voltage value of the voltage power supply 2 is fixed at 44 V, the total voltage is 44 to 60 V, and the resistance component 32 of the load device 3 is 1.6 Ω, and the settable current range is 27.5.
~ 37.5A. When the current value increases, the value of the second term on the right side of Equation (1) increases, the value that can be applied to the first term decreases, and the transient response slows down.

Assuming that the current set value i is 20 A and the total voltage range is 44 to 60 V, the allowable resistance R of the resistance component 32 of the load device 3 is 2.2 to 3 Ω. Become slow. As described above, in the circuit of FIG. 1 in which the power supply voltage 2 voltage value is fixed, problems such as restriction of the operation range and inability to increase the operation speed occur depending on the set current value and the resistance value of the load device.

FIG. 2 shows an embodiment according to claim 2 of the present invention which has been made to solve such a problem. In FIG. 2, reference numeral 3 denotes the same load device as in FIGS. 1, 3 and 4. is there. Reference numeral 21 denotes a variable current power supply, a subtractor 213 subtracts a difference between a current setting signal 211 and a current detection signal 212 output from the current detector 216 (current setting signal 211-current detection signal 212), and a voltage controller 214 To adjust the voltage value of the high-speed variable voltage power supply (first voltage power supply) 215 through the current setting signal 2
Operate to match 11.

Reference numeral 22 denotes a variable voltage power supply.
21 and a voltage detection signal 231 which is an output of the voltage detector 23
(The voltage detection signal 231 -the voltage setting signal 221) is subtracted by the subtractor 222, the voltage value of the low-speed variable voltage power supply (second voltage power supply) 224 is adjusted through the voltage controller 223, and the variable voltage power supply is adjusted. 215 is the voltage setting signal 22
Operate to match 1. In this case, the voltage setting signal 2
When the voltage of the variable voltage power supply 224 increases, the voltage value of the variable voltage power supply 224 has a rising polarity. When the voltage value of the variable voltage power supply 224 rises, the current of the load device 3, that is, the current of the current detector 216 rises, so that the voltage of the variable voltage power supply 215 falls to match the voltage setting signal 221.

As in the above-described specific example, the voltage range of the high-speed variable voltage power supply 215 is 0 to 16 V, and the voltage range of the low-speed variable voltage power supply 224 is 0 to 60 V. Assuming that the resistance value R of the resistance component 32 of the load device 3 is 1.6Ω, the voltage power supply 2
Since the total voltage range of 15 and 224 is 0-76V,
The current range is 0 to 47.5 A, while the current range is 27.5 to 37.5 A in the previous example.

If the current set value is 20 A and the initial value of the variable voltage power supply is 10 V, the voltage value of the variable voltage power supply is 2
The current rises to a maximum value of 16 V in an attempt to flow 0 A, but since the total voltage is 16 + 10 = 26 V, the load device current flows only up to 16.25 A. Here, the voltage power supply 22
If the voltage setting signal 221 is set to the minimum required value of the current power supply 21, for example, 1 V, the voltage value of the variable voltage power supply 224 is increased because the voltage detection signal 231 is higher than the set value, and finally the voltage The voltage value of the voltage 215 is 1 V and the voltage value of the voltage power supply 224 is 31 V, so that the load device 3 can flow the set value of 20 A. Such voltage sharing reduces the power capacity of the expensive high-speed current power supply 21 and causes the low-cost low-voltage power supply 22 to bear the burden, thereby contributing to lower cost of the entire apparatus. Even when the resistance component of the load device 3 fluctuates, the load device current can follow the setting signal by the same operation.

[0018]

As described in detail above, according to the present invention, a high-speed and low-cost current power supply can be realized by combining a small-capacity and high-speed current power supply with a low-speed and low-cost voltage power supply. The above utility value is great.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a current power supply device according to claim 1 of the present invention.

FIG. 2 is a diagram showing a configuration of a current power supply device according to claim 2 of the present invention.

FIG. 3 is a diagram showing an example of a configuration of a conventional current power supply device.

FIG. 4 is a diagram showing the internal configuration of a conventional current power supply.

[Explanation of symbols]

1, 21 Current power supply 2, 15, 22, 215, 224 Voltage power supply 3 Load device 11, 211 Current setting signal 12, 212 Current detection signal 13, 213, 222 Subtractor 14, 223 Voltage controller 16, 216 Current detector 23 voltage detector 31 inductance component 32 resistance component 221 voltage setting signal

Claims (2)

[Claims] 1. A current power supply device wherein a current power supply, a voltage power supply and a load device are connected in series. 2. A current detector for connecting a first voltage power supply, a second voltage power supply and a load device in series, and detecting a current of the load device, and a voltage detector for detecting a voltage of the first voltage power supply. Wherein the voltage of the first voltage power supply is controlled by the output of the current detector, and the voltage of the second voltage power supply is controlled by the output of the voltage detector.