JPH08275389A - Dc power device - Google Patents

Abstract

PURPOSE: To detect a trouble quickly and stop operation of a power circuit which has the trouble before it is seriously damaged by providing a system with a current value setting circuit and a power supply trouble judging circuit for calculating an allowable current per one power circuit from the total current value and comparing the value with the output current of each power circuit and then stopping by force a power circuit which has a trouble. CONSTITUTION: An attenuator 19 outputs an upper limit value of an allowable current per one power circuit and an attenuator 20 outputs a lower limit value. A comparator 22 compares an output current value of a power circuit 14 with the upper limit value of an allowable current. A comparator 23 compares the output current value of the power circuit 14 with the lower limit value. When the comparator 23 determines that the power circuit 14 has a trouble, it outputs a signal to an OR circuit 24. When the OR circuit 24 determines that the power circuit 14 has a trouble, it turns a relay circuit 2 off. A trouble power supply displaying circuit 26 displays which power circuit has a trouble. Just at a time when the output current value exceeds the allowable range, it is determined that the power circuit 14 has a trouble and then the operation of the power circuit 14 is stopped immediately after a trouble is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct current control type DC power supply circuit (hereinafter referred to as a power supply circuit) connected in parallel to a load device which requires a large current, to supply electric power. In the power supply, if one or several of the connected power supply circuits become abnormal, a function that can detect the abnormality promptly and accurately determine which power supply circuit is abnormal The present invention relates to a highly reliable DC power supply device provided.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional DC power supply device. In FIG. 5, 1 is a primary power supply, 2 is a relay circuit, and 3 is a relay circuit.
Is an input capacitor, 4 is a transformer for power conversion, 5 is a switching transistor, 6 is a drive circuit for driving the transistor 5, 7 is a rectifying diode, 8 is a smoothing choke coil, 9 is an output capacitor, and 10 is A current control circuit for controlling the output current, 11 is a voltage control circuit for controlling the output voltage, 12 is a pulse width control circuit for determining the switching pulse width by the outputs of the current limiting circuit 10 and the voltage control circuit 11, 13 is a voltage control circuit 10
The relay drive circuit that turns off the input relay circuit when the output current becomes abnormal when the output of
A first power supply circuit composed of the respective circuits, 15 is a second power supply circuit composed of the same circuit as the first power supply circuit 14, 16
Is a load device, and 17 is an abnormality monitor circuit for detecting an abnormality in each power supply circuit.

Next, the operation of the conventional device shown in FIG. 5 will be described. The power supply circuit 14 shown in FIG. 5 is a current control type switching power supply, which is the mainstream in a system that supplies power by connecting a plurality of power supply circuits in parallel. The operation is such that the transistor 5 is turned on / off and a pulse current is passed through the primary side of the transformer 4, thereby transmitting power to the secondary side of the transformer 4 and rectifying the power generated on the secondary side of the transformer 4. After rectifying with diode 7,
Electric charges are stored in the output capacitor 9 via the choke coil 8 and supplied to the load device 16 as a predetermined DC voltage. The voltage control circuit 11 detects the voltage across the capacitor 9 and sends a signal to the pulse width control circuit 12 to widen the ON width of the transistor 5 when the voltage drops and narrow the ON width when the voltage rises. On the other hand, the current control circuit 10
The output current of the choke coil 8 is detected, and when the current exceeds a predetermined value, a signal is sent to the pulse width control circuit 12 so as to narrow the ON width of the transistor 5. Pulse width control circuit 12
Determines the ON width of the transistor 5 based on the signals from the current control circuit 10 and the voltage control circuit 11, and transmits a drive signal to the transistor drive circuit 6. As a result, the on / off ratio of the switching of the transistor 5 is controlled by both the output voltage and the output current, and the voltage across the capacitor 9 is always kept constant while limiting the maximum output current. Therefore, even if a plurality of similar power supply circuits are connected in parallel, each of them is controlled so as not to flow a current higher than the rated current, so that it is possible to supply electric power that is twice the rated electric power.

When a plurality of power supply circuits are connected in parallel and used, several power supply circuits are provided in excess of the number of power supply circuits capable of supplying the power required by the load device, for the purpose of improving system reliability. I keep a lot of connections so that the system will not be affected even if some of them stop. for that reason,
Even if one power supply circuit stops, there is no change in the output voltage or the total output current, so it will not be possible to detect an abnormality. The abnormality monitor circuit 17 is connected to each power supply circuit and switching stops due to an abnormality. It is for detecting which power supply circuit is operating and notifying which power supply circuit has stopped. Further, the relay drive circuit 13 includes the current control circuit 10
The relay circuit in the input stage of the power supply in which the abnormality has occurred is turned off by receiving the signal from the power supply so that the input of other power supplies is not affected. However, there is no guarantee that the output current of each power supply circuit will flow evenly, and even if one power supply circuit becomes abnormal, there is no change in the overall output voltage or output current. The relay 5 is set to be turned off only when the transistor 5 is short-circuited, the control circuit or the like fails, and an excessively large current exceeding the rating flows or no current flows.

[0005]

Since the conventional DC power supply device is constructed as described above, even if the relay circuit is turned off and the power supply circuit is disconnected, somewhere in the power supply circuit is already damaged. In the worst case, there were cases where repairs such as burnout were difficult. Even if the power supply where an error occurs is displayed on the error monitor circuit, if the power supply circuit and the display are separated, there is no indication at the place to replace the power supply circuit, or the primary input for replacement is displayed. Since the display disappeared when the power was turned off,
There was a high possibility of not knowing which power circuit to replace. Furthermore, since the abnormality monitor circuit must receive signals from all power supply circuits, if the number of power supply circuits is large, the number of interface circuits and interface cables will be enormous and the device will become large. was there.

The present invention has been made in order to solve the above-mentioned problems, and detects an abnormality before the power supply circuit becomes difficult to repair and turns off the input primary power supply at a place for replacement. Even if the power supply to be replaced is known at a glance, the normal power supply circuit will not be accidentally replaced, and the interface between each power supply circuit and the abnormality monitor circuit will be simplified, and the entire device The purpose is to miniaturize.

[0007]

A direct current power supply device according to a first embodiment of the present invention detects a load current at an input stage of a load device and determines an allowable current per power supply circuit from the total current value. Calculated and compared with the output currents of all power supply circuits, the current value setting circuit for forcibly stopping the power supply circuit that has a little abnormality is in the abnormality monitor circuit, and the power supply abnormality determination circuit is the power supply circuit. It is prepared for inside.

Further, the DC power supply device according to the second embodiment of the present invention uses the residual charge remaining in the input capacitor of the power supply circuit to turn on the light emitting diode by a signal for forcibly stopping the abnormal power supply circuit. Even if the power is turned on by a low current operation and the primary power supply of the input is stopped, a lighting circuit for abnormality display is provided in the power supply circuit so that an abnormality can be confirmed at the place where the power supply circuit is placed.

Further, in the DC power supply device according to the third embodiment of the present invention, a plurality of power supply circuits connected to each other are replaced with an n-th order matrix, a High signal is sequentially sent for each row, and an abnormality occurs in that row. Low indicating only the power supply circuit is abnormal
By sending the signal of, and checking which column power supply circuit is abnormal for each row, the circuit that can confirm which power supply circuit is abnormal among all the power supply circuits is It is provided in the monitor circuit.

[0010]

According to the DC power supply device of the first embodiment of the present invention, even when some of the power supply circuits connected in parallel have some abnormality, the abnormality is promptly detected and the abnormality is caused. It can be shut down and disconnected from the input primary power source before the power supply circuitry is seriously damaged.

Further, according to the DC power supply device of the second embodiment of the present invention, even if the input primary power supply is turned off when some of the power supply circuits connected in parallel have some abnormality. In addition, the abnormal power supply circuit can be confirmed on the spot without having to go to the abnormal power supply display circuit, and the abnormal power supply circuit can be replaced safely and accurately.

Further, according to the DC power supply device of the third embodiment of the present invention, even if a plurality of power supply circuits are connected in parallel and some of them become abnormal, the power supplies connected in parallel are connected. It is possible to accurately detect which power supply circuit has an abnormality by using twice the number of signals as n when the circuit is replaced with an nth-order matrix, and to detect the interface circuit and interface cable of the abnormality monitor circuit. Because of simplification, the entire DC power supply device can be made very small.

[0013]

【Example】

Example 1. 1 is a circuit configuration diagram showing a first embodiment of the present invention. In the figure, 1 to 17 are the same as the above-mentioned conventional device and circuit, and 18 is a total current value detected at an input stage of a load device. For detecting the current, 19 is a first attenuator that determines the upper limit of the permissible current per unit from the total current value detected by the current detection circuit 18, and 20 is the current detection circuit 1
The second attenuator that determines the lower limit of the permissible current per unit from the total current value detected by 8, 21 is a current value setting circuit configured by the circuits shown in 18 to 20, 22 is the upper limit of the permissible current And a first comparator 23 for comparing the output current of the power supply circuit 14 detected by the current control circuit 10 with a second comparator 23 for comparing the lower limit value of the allowable current with the output current of the power supply circuit 14 detected by the current control circuit 10. 2 is a comparator, 24 is an OR circuit for taking the logical sum of the outputs of the comparators 22 and 23, 25 is a circuit shown by 23 to 24, and when it is determined that there is an abnormality, the relay drive circuit 13 and the pulse width control circuit 12 A power supply abnormality determination circuit that transmits a signal for relay-off and power supply stop to 26, and an abnormal power supply display circuit 26 that sums up the outputs from the abnormality determination circuits of each power supply circuit and indicates which power supply circuit has an abnormality. .

The operation will be described in detail below with reference to the drawings. In the configuration as shown in FIG. 1, when the number of power supply circuits connected in parallel is m, the attenuator 19 reduces the output of the current detection circuit 18 to 1 / m, and further sets a value p ( However, a value obtained by multiplying p by 1 or more) is output as the upper limit value of the permissible current per power supply circuit. In addition, the attenuator 20 sets the output of the current detection circuit 18 to 1 / m, and further multiplies the value q indicating the allowable range (where q is 1 or less) by the lower limit value of the allowable current per power supply circuit. Output as. For example, 25 power supply circuits 14 are connected in parallel, and the allowable error in the current value per unit is 1 for both the upper limit and the lower limit.
Assuming 0%, when the total current value detected by the current detection circuit 18 is I, the upper limit value im of the permissible current per unit im
The values of ax and the lower limit value imin are as in "Equation 1".

[0015]

[Equation 1]

The comparator 22 compares the upper limit value of the allowable current, which is the output of the attenuator 19, with the output current value of the power supply circuit 14 detected by the current control circuit 10, and the output of the attenuator 19 is smaller. If it becomes, it is judged to be abnormal and H is input to the OR circuit 24.
Outputs IGGH. On the other hand, the comparator 23 compares the lower limit value of the allowable current, which is the output of the attenuator 20, with the output current value of the power supply circuit 14 detected by the current control circuit 10, and the attenuator 20
When the output of is larger than that, it is determined to be abnormal, and High is output to the OR circuit 24. When either one of the comparators 22 and 23 outputs High, the OR circuit 24 determines that the power supply circuit is abnormal, and the relay drive circuit 13
And a signal for turning off the relay circuit 2 and an off signal for stopping the switching operation to the pulse width control circuit 12. Further, the abnormal power supply display circuit 26 collects the outputs from the abnormality determination circuits in each power supply circuit, displays which power supply circuit has the abnormality, and gives an instruction to replace the power supply circuit. As described above, the current value output by the power supply circuit 14 is calculated from the current value consumed by the load device 16, and the power supply circuit 14 is switched because it is determined to be abnormal when it exceeds the allowable range. Even if the characteristics of the transistor 5 are deteriorated or the current control circuit 10, the voltage control circuit 11, the pulse width control circuit 12, and the like become out of order and the power supply circuit 14 cannot be controlled, an abnormality is immediately detected and the power supply circuit 1 is detected.
4 can be stopped, and an abnormality can be detected before the serious damage such as burnout occurs, and the power supply circuit can be replaced / repaired.

Example 2. FIG. 2 is a circuit configuration diagram showing a second embodiment of the present invention. Reference numerals 1 to 26 in the figure are the same as or equivalent to the conventional circuit and the circuit described in the first embodiment, and 27 is a power supply circuit 14. When an abnormality occurs in the attached power supply circuit 14, a light emitting diode for notifying the abnormality, 28 is a junction type field effect transistor (hereinafter J) for lighting the light emitting diode 27 with a constant current.
-FET), 29 is a resistor for keeping the gate-source voltage constant so that the J-FET 28 operates in constant current, and 30 is a thyristor for turning on the J-FET 28 to light the light emitting diode 27. Is.

The operation will be described in detail below with reference to the drawings. In the configuration of FIG. 2, the relay circuit 2 has a fulcrum terminal connected to the input capacitor 3 side, and the anode of the light emitting diode 27 is connected to an empty terminal connected when the relay is turned off. When the relay circuit 2 is turned off, the residual charge remaining in the input capacitor 3 tries to flow through the light emitting diode 27. Also,
The relay drive circuit 13 is provided with the thyristor 30 only when the relay circuit 2 is turned off by the signal from the power supply abnormality determination circuit 25.
Send an ON signal to. When the thyristor 30 is turned on, the electric charge in the input capacitor 3 is changed to the light emitting diode 27.
Through the J-FET 28 and the resistor 29, and the light emitting diode 27 lights up. In the J-FET 28, if the voltage between the gate and the source is constant, the flowing current becomes a constant current regardless of the voltage of the input capacitor 3. If the current value is Id, the pinch-off voltage of the J-FET is Vp, and the drain saturation current at zero bias is IDSS,
The value R of the resistor 29 is approximately determined by "Equation 2".

[0019]

[Equation 2]

The current value Id is set to be the minimum current value at which the light emitting diode 27 used can emit light, the input voltage of the power supply circuit 14 is Vin, and the time for keeping the light emitting diode 27 lit is t, The ON voltage Vd of the light emitting diode 27 and the minimum operating voltage of the J-FET 28 are set to VL.
If the ON voltage of T and the thyristor 30 is Vs, if the capacitance C of the input capacitor 3 is equal to or more than the value shown in "Equation 3",
The light emitting diode 27 can be left on for a required time.

[0021]

(Equation 3)

In this embodiment, the constant current circuit is a J-FE.
Although it is configured by T, the same effect can be obtained by using a low current diode or a similar constant current circuit, and the same effect can be obtained by using a display function other than a light emitting diode, such as a liquid crystal element. It is clear that

Example 3. FIG. 3 is a circuit configuration diagram showing a third embodiment of the present invention, in which 1 to 26 in the figure are the same as or equivalent to the conventional circuit and the circuit described in the first embodiment, and 31 is for outputting an abnormal signal. , 32 is an AND circuit for taking a logical product, 33 is a pull-up resistor, 34 is a transistor group for sending a signal to n rows when a plurality of power supply circuits connected in parallel are replaced with an n-th order matrix, Reference numeral 35 designates an infinitely repeating shift register for sequentially turning on / off the n transistor groups 34 one by one, and 37 designates a first power supply circuit for sending a signal to each power supply circuit connected to the same row as the power supply circuit 14. Is a transistor.

FIG. 4 is a diagram showing a connection example for explaining the operation of the embodiment shown in FIG.
Reference numerals 4 to 35 and 37 are the same as or equivalent to the above-described conventional circuit and the circuits described in the first and second embodiments and FIG. 3, and 36 is the same as the power supply circuit 14 and includes m power supply circuits. Power supply circuit group replaced by the following matrix, 38-
Reference numeral 41 is a second transistor to a fifth transistor when the n-th matrix is assumed to be a fifth-order matrix.

The operation will be described in detail below with reference to the drawings. Here, for convenience of explanation, the n-th order matrix will be described as a fifth-order matrix. In the configuration of FIG. 4, the shift register 3
5 is a first transistor 37 to a fifth transistor 41
Are sequentially turned on / off one by one, and when the fifth transistor 41 is turned off, the first transistor 37 is turned on again and turned on / off forever while power is supplied to the abnormality monitor circuit 17. It is repeating. Now, assuming that the first transistor 37 is turned on, each of the five power supply circuits placed in the first row has a high voltage.
Is transmitted. When one of the five power supply circuits, for example, the power supply circuit 14 becomes abnormal, the power supply abnormality determination circuit 25 shown in FIG.
The signal is transmitted to one input of the D circuit 32, and the first transistor 37 is turned on, so that the other input is also High.
Signal is sent. Thereby, the AND circuit 3
2 sends a High signal to the transistor 31, and a Low signal indicating an abnormality is transmitted to the abnormal power supply display circuit 26 in the signal of the fifth column to which the power supply circuit 14 is connected. If there is no abnormal power supply circuit, all the high power signals are transmitted to the abnormal power supply display circuit 26, indicating that the five power supply circuits in the first row to the first to fifth columns are normal. To be done. Similarly, when the second transistor 38 is turned on, the first transistor 3
7 is turned off, and each of the five power supply circuits in the first row sends a High signal to the abnormal power supply display circuit 26. Instead, the five power supply circuits placed in the second row are sent a high signal to the AND circuits in the respective power supply circuits, causing an abnormality in the power supply circuits placed in the second row. If there is a power supply circuit that operates, the signal of that column becomes Low. As a result, the first transistor 37 to the fifth transistor 41 are sequentially turned on / off, and if the on / off signal and the signal connected to each column are monitored, that is,
It is possible to confirm whether all the power supply circuits placed in the fifth-order matrix are abnormal or normal by monitoring which column has an abnormality when which transistor is turned on. In other words, it can be seen that, in order to monitor all 25 power supply circuits connected in parallel, only 10 signals can be monitored instead of 25 signals.

In this embodiment, the current control type DC power supply circuits are connected in parallel. However, even if any other type of power supply circuit is connected in parallel, it is not connected in parallel.
However, even if a plurality of power supply circuits are used at the same time, it can be easily imagined that the same effect can be obtained with the same configuration.

[0027]

As described above, according to the first embodiment of the present invention, since the current value allowed for each power supply circuit is calculated from the total output current of the DC power supply device, the current of the load device is rated. Even when the number of power supply circuits is smaller or the number of power supply circuits used is large, it is possible to detect in advance the power supply circuits that are likely to become abnormal, and the power supply circuits cannot be repaired due to such an abnormality. Before serious damage
Since the power supply circuit can be stopped, it is possible to realize a safer, more reliable, and low repair cost DC power supply device.

Further, according to the second embodiment of the present invention, when the power supply circuit in which the abnormality has occurred is replaced, the power supply circuit in which the abnormality has occurred can be confirmed at the replacement site, and even if the input primary power supply is turned off. Since the display indicating the abnormality is lit, the power supply circuit can be replaced safely and without mistake, so that it is possible to realize a DC power supply device having higher safety and excellent maintainability.

Further, according to the third embodiment of the present invention, even if m power supply circuits are connected in parallel to detect an abnormality in all the power supply circuits, the minimum integer exceeding the square root of the number m is doubled. It is possible to check with the number of signals just set, the interface circuit of the abnormality monitor circuit can be simplified, and the number of interface cables and connectors etc. can be reduced, making it more compact.
It is possible to realize a lightweight DC power supply device.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a DC power supply device according to the present invention.

FIG. 2 is a diagram showing a second embodiment of the DC power supply device according to the present invention.

FIG. 3 is a diagram showing Embodiment 3 of the DC power supply device according to the present invention.

FIG. 4 is a diagram for explaining the operation of the third embodiment of the DC power supply device according to the present invention.

FIG. 5 is a diagram showing a conventional DC power supply device.

[Explanation of symbols]

1 primary power supply, 2 relay circuit, 3 input capacitors,
4 transformers, 5 transistors, 6 drive circuits, 7
Rectifier diode, 8 smoothing choke coil, 9 output capacitor, 10 current control circuit, 11 voltage control circuit, 12 pulse width control circuit, 13 relay drive circuit,
14 first current control type DC power supply device, 15 second current control type DC power supply device, 16 load device, 17 abnormality monitor circuit, 18 current detection circuit, 19 first attenuator,
20 second attenuator, 21 current value setting circuit, 22 first comparator, 23 second comparator, 24 OR circuit, 2
5 current abnormality judgment circuit, 26 abnormal power supply display circuit, 27
Light emitting diode, 28 junction type field effect transistor, 29 resistor, 30 thyristor, 31 transistor, 32 AND circuit, 33 pull-up resistor, 3
4 transistor group, 35 shift register, 36 power supply circuit group, 37 1st transistor, 38 2nd transistor, 39 3rd transistor, 40 4th transistor, 41 5th transistor.

Claims (3)

[Claims] 1. A relay circuit for shutting off an input current from a primary power supply, a capacitor for smoothing the input current, a transistor for switching a current from the primary power supply and the capacitor through a transformer, and for driving the transistor. Drive circuit, a rectifying diode connected to the secondary side of the transformer for rectifying a current, a choke coil and a capacitor for smoothing the current from the rectifying diode, and an output current of the choke coil for detecting a predetermined current. A current control circuit that controls the switching-on width of the transistor so that a current does not flow more than a value, and a voltage control circuit that controls the switching-on width of the transistor so that the inter-terminal voltage of the capacitor becomes a predetermined voltage,
A current control type DC power supply comprising a pulse width control circuit connected to the current control circuit and the voltage control circuit to determine the ON width of the transistor, and a relay drive circuit which receives a signal from the current control circuit and turns off the relay circuit. The circuit
In a DC power supply device having an abnormality monitor circuit that is connected in parallel to supply power to a load device and that monitors a plurality of connected power supply circuits for abnormalities, a current that detects a current at the input stage of the load device. A current value setting circuit including a detection circuit, a first attenuator that determines the upper limit of the output current per unit from the detected current value, and a second attenuator that determines the lower limit of the output current per unit And a first comparator for comparing the output of the first attenuator with the output from the current limiting circuit of the power supply circuit, and for comparing the output of the second attenuator with the output from the current limiting circuit. A second comparator, a power supply abnormality determination circuit that is an OR circuit that takes the logical sum of the outputs of the first comparator and the second comparator, and which of the power supply circuits connected in parallel is abnormal. An abnormal power supply display circuit for identifying DC power supply device, characterized in that. 2. A terminal serving as a fulcrum of the relay circuit is connected to the input capacitor side, and is connected to an open side contact and a light emitting diode which emits light by utilizing the residual charge of the input capacitor, and an anode side of the light emitting diode. A junction type field effect transistor for lighting the light emitting diode with a constant current, a resistor connected to the source side of the field effect transistor for determining a gate-source voltage value, and a GND side of the resistor and the input capacitor. The power supply circuit is provided with a lighting circuit for abnormality display, which is connected between the terminal and the abnormality determination circuit and determines that the abnormality is detected, and the relay drive circuit turns on the relay circuit and simultaneously turns on the thyristor. Claim 1 characterized by the above.
DC power supply described. 3. A plurality of power supply circuits connected in parallel, wherein an abnormal signal output transistor is connected with a collector as a signal output terminal, and one of the inputs is connected to the power supply abnormality determination circuit. An AND circuit that connects one input to a transistor group in the abnormality monitor circuit and logically ANDs the signals of each other to drive the transistors, and replaces the plurality of power supply circuits connected in parallel with an n-th order matrix And a pull-up resistor configured to check an abnormal signal for each row, a transistor group including n transistors, a shift register circuit that alternately turns on the transistor group, and the same output as the shift register circuit. A signal line in which each collector output of the signal output transistors of the power supply circuit connected to the column is connected in parallel is monitored, and a plurality of units are connected in parallel. 2. The DC power supply device according to claim 1, further comprising: an abnormal power supply display circuit for determining which of the power supply circuits is abnormal in the abnormality monitor circuit.