JPH04285880A - Dc power supply apparatus - Google Patents

Abstract

PURPOSE:To foreknow the generation of abnormality in a DC power supply apparatus from the battery current, battery voltage and load current in the DC power supply apparatus. CONSTITUTION:A DC power supply apparatus is constituted of a first current detector 9 detecting the battery current in the DC power supply apparatus, a first voltage detector 10 detecting the battery voltage in said apparatus, a second current detector 11 detecting the load current in the apparatus and an abnormality diagnosing circuit 12 receiving three signals of the respective currents and the voltage to output various abnormal alarms beforehand from internal processing results.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply that rectifies AC power and supplies DC power to a control section of a power generation plant, and more particularly to a DC power supply that detects abnormalities in the DC power supply in advance.

0002

[Prior Art] Generally, the control power source for many devices used to control power generation plants is a DC power source, and the AC power sent from the transformer or distribution line in the plant is converted to DC power by a DC power supply device. It is supplied to each control section within the rectification plant. Also, when the AC power supply stops functioning (during a power outage)
A battery is provided in the DC power supply so that power can be continuously supplied to each control section even if the rectifier in the DC power supply fails.

[0003] A conventional DC power supply device will be explained below with reference to FIG. The DC power supply device 1 converts AC power from a transformer in the plant into DC power via the power supply unit 2, and supplies the DC power to a plurality of control units 3 in the plant. Also,
A battery 4 is provided in the DC power supply device 1 for charging surplus DC power from the power supply unit 2 when the control unit 3 is under a light load.

The battery 4 is used when it is impossible to supply DC power due to a failure of the power supply unit 2 or when the rated DC power supplied from the power supply unit 2 is insufficient due to a transient increase in the load on the control unit 3. It discharges and supplies the DC power required by the control unit 3. The breaker 5 interrupts the DC power (hereinafter referred to as load current) output from the DC power supply device 1 to the control unit 3. Next, the operation of the DC power supply device 1 will be explained.

The alternating current output from the transformer in the power plant is rectified by the power supply unit 2 in the DC power supply unit 1 and output as direct current, which is then supplied to the control unit 3 via the circuit breaker 5 which is closed, and is then cut off. It is supplied to each control circuit via the circuits 6a to 6g.

Furthermore, when the load on the control section 3 increases transiently, the required load current exceeds the rated power supply of the power supply section 2, so the battery 4 supplies the current that is insufficient. Thereafter, when the load decreases and becomes large enough to match the power from the power supply section 2, the supply of current from the battery 4 is stopped. In addition, if the transformer, power supply unit 2, etc. in the plant fail and DC power cannot be supplied to the control unit 3, the battery
DC power is supplied from the controller 3 to the controller 3.

As described above, the DC power supply device 1 has an important role of supplying power to the control section 3, so if a failure occurs, it will have a large impact on the plant. Therefore, it is necessary to diagnose abnormalities in the DC power supply device. Therefore, conventional diagnosis will be described. When a voltage drop occurs due to deterioration in the performance of the power supply unit 2 and long-term discharge of the battery 4, the voltage relay 7 in the control unit 3 detects the voltage drop in the control unit 3 and issues an alarm. detects abnormalities, corrects them, and stops them. Similarly, when the current in the control unit 3 causes a ground fault, the ground fault relay 8 in the control unit 3 detects the ground fault and issues an alarm, and then the operator detects the location of the abnormality and makes corrections. Perform a stop.

[0008]

[Problems to be Solved by the Invention] As described above, the occurrence of an abnormality in a conventional DC power supply is detected by the voltage relay and ground fault relay in the control section to which the DC power is supplied, and various alarms are issued. was outputting.

[0009] However, since the above-mentioned alarm is output at the time when an abnormality occurs, countermeasures have to be taken after the abnormality is detected after the abnormality occurs. Therefore, for example, a large amount of time is consumed in repairing the power supply section in the DC power supply device and charging the battery, so that there is a drawback that the plant cannot be operated during that period. In particular, the occurrence of abnormalities at large-capacity power plants that supply electricity to areas where large cities are concentrated has a very large impact on the balance between electricity demand and supply. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a DC power supply device that can predict the occurrence of an abnormality in the DC power supply device in advance. [Structure of the invention]

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a power supply section that rectifies alternating current into direct current and supplies direct current power to a plurality of control sections in a plant, and a power supply section that uses surplus current from this power supply section. A DC power supply device comprising: a battery that is charged and supplies DC power to the control unit when the output of the power supply unit decreases or when the load of the control unit transiently increases;

[0011] The amount of charging current and discharging current from the battery per predetermined time is integrated, and the remaining capacity of the battery is detected from the integrated value of each amount of electricity, and this remaining amount is set in advance. When the battery capacity reaches the specified capacity, a low battery capacity alarm will be output.

[0012] Also, the amount of electricity per predetermined time of the charging current and discharging current from the battery is integrated, and the above respective integrated values are compared. If the integrated value of the discharging current is large and exceeds a preset value, , outputs a battery discharge continuation alarm, detects the voltage change rate of the battery voltage per predetermined time, and outputs a battery voltage decrease alarm when a rate of change in a decreasing direction is detected; If the load current is less than the rated DC power supplied from the power supply and the battery is discharging, a power supply abnormality alarm will be output.

0
[013] The present invention is also characterized by having an abnormality diagnosis circuit that constantly detects the battery voltage and outputs a battery voltage drop alarm when the voltage reaches a preset voltage.

[0014]

[Operation] The DC power supply of the present invention is constructed as described above, and the abnormality diagnostic circuit constantly detects the battery current, battery voltage, and load current in the DC power supply, and detects abnormalities within the DC power supply. By predicting the situation in advance, it is possible to respond quickly even when an abnormality occurs.

[0015]

Embodiment An embodiment of the present invention will be described with reference to FIG. However, explanations of components that overlap with those of the conventional DC power supply device shown in FIG. 3 will be omitted. In FIG. 1, a first current detector 9 detects the battery current of the battery 4, and a first voltage detector 10 detects the battery voltage of the battery 4.

The second current detector 11 detects the load current. The abnormality diagnosis circuit 12 takes in the battery current, battery voltage, and load current detected by each of the above-mentioned detectors as input signals, and when an abnormality is detected as a result of abnormality diagnosis, the alarm contact 12a is closed and various abnormalities are detected. Outputs a warning.

Next, the normal operation of the DC power supply device according to this embodiment will be explained. AC supplied from a transformer in the plant is rectified and converted into DC via a power supply section 2 in a DC power supply 1.

Generally, during normal operation of a power generation plant, the DC power supply via the power supply section 2 is connected to the control section 3 in the power generation plant.
supplied to However, during transient operation of the power generation plant, the load on the control section 3 increases, so the power supply section 2
The rated DC power supplied by the plant will be insufficient. Therefore, in the above case, the battery 4 in the DC power supply 1
The necessary DC power is obtained by supplying the insufficient DC from the

After that, when the transient load on the control unit 3 is reduced again and the load returns to normal plant operation, the supply of DC from the battery 4 is stopped, and the circuit is closed from the power supply unit 2 to the control unit 3. Rated DC power is supplied through the device 5. In addition, when the load on the control section 3 becomes lighter than usual, the surplus current excluding the DC power required by the control section 3 out of the rated DC power supplied from the power supply section 2 is transferred to the battery 4. It will be charged. Next, the internal processing of the abnormality diagnosis circuit of the DC power supply device according to this embodiment will be explained with reference to FIG.

The determining unit 13 receives the battery current detected by the first current detector 9 in the DC power supply 1, and determines whether the battery 4 is being charged or discharged based on the direction of the battery current. to judge whether The first integration unit 14 is
When the determining unit 13 determines that the battery 4 is in a charging state, it calculates the integrated value of the charging current that is charged to the battery 4 per predetermined time. When the determining unit 13 determines that the battery 4 is in a discharged state, the second integrating unit 15 calculates an integrated value of the discharge current discharged from the battery 4 per predetermined time.

The remaining amount detection unit 16 subtracts the integrated value of the charging current calculated by the first integrating unit 14 from the integrated value of the discharging current calculated by the second integrating unit 15, and calculates the amount of flow out from the battery 4. calculate. Then, the remaining capacity of the battery 4 is detected from the amount of outflow from the battery 4.

The battery capacity reduction alarm output unit 17 outputs the battery capacity when the remaining capacity of the battery 4 detected by the remaining capacity detection unit 16 reaches a predetermined value (minimum capacity that can safely and reliably stop the plant). Outputs a drop alarm. The first comparator 18 compares the integrated value of the discharge current of the battery 4 detected by the first integration part 14 with the integrated value of the charging current of the battery 4 detected by the second integration part 15.

The battery discharge alarm output unit 19 detects that the integrated value of the discharging current is larger than the integrated value of the charging current by the first comparing unit 18, and the integrated value of the discharging current is greater than or equal to a preset value. In this case, a battery discharge continuation alarm is output.

The second comparator 20 is a second comparator in the DC power supply 1.
The load current detected by the current detector 11 is taken in and compared with a preset value of the rated DC power supplied from the power supply unit 2. The power supply abnormality alarm output section 21 is connected to the second comparison section 2
If the value of the load current is 0 and the battery 4 is discharging, a power supply abnormality alarm is output. The voltage change rate detection unit 22 is the first voltage detector 1 in the DC power supply 1.
The voltage change rate per predetermined time of the battery voltage detected at 0 is detected. The battery voltage decrease alarm output unit 23 outputs a battery voltage decrease alarm when the voltage change rate detection unit 22 continuously detects a rate of change in the voltage decreasing direction.

When the battery voltage detected by the first voltage detector 11 in the DC power supply 1 decreases and reaches the lowest voltage that can safely and reliably stop the plant, the battery voltage drop alarm output unit 24 outputs the battery voltage. - Outputs voltage drop alarm.

As explained above, the battery current, battery voltage, and load current are detected, and from the relationship therebetween, abnormalities in the battery and power supply section can be predicted in advance, and countermeasures can be quickly taken. In addition, in plants where a sequence controller is installed, it can be implemented simply by adding software.

[0027]

According to the present invention, the current and voltage of the battery in the DC power supply device and the current supplied from the DC power supply device to the control unit are detected and input into the abnormality diagnosis circuit, and the DC power supply is detected based on the relationship between each of them. By predicting equipment abnormalities in advance, it is possible to prevent the occurrence of abnormalities and to quickly respond to the occurrence of abnormalities.

[Brief explanation of the drawing]

[Figure 1] Configuration diagram of a DC power supply device according to this embodiment

[Figure 2]
Internal processing diagram of the abnormality diagnosis circuit of this embodiment

[Figure 3] Configuration diagram of a conventional DC power supply device

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... DC power supply device, 2... Power supply part, 3... Control part, 4... Battery, 5, 6a-6g... Breaker, 7... Voltage relay,
8... Earth fault relay, 9... First current detector, 10... First voltage detector, 11... Second current detector, 12... Abnormality diagnostic circuit,
12a... Alarm contact, 13... Judgment section, 14... First integration section,
DESCRIPTION OF SYMBOLS 15...Second integration part, 16...Remaining amount detection part, 17...Battery-capacity reduction alarm output part, 18...First comparison part, 19...Battery-discharge alarm output part, 20...Second comparison part, 21...Power supply 22...Voltage change rate detection section, 23...Battery-voltage decrease alarm output section, 24...Battery-voltage decrease alarm output section

Claims (5)

[Claims] 1. A power supply unit that rectifies AC power into DC power and supplies the DC power to a plurality of control units in the plant; In a DC power supply device comprising a battery that supplies DC power to the control unit when the load on the control unit increases, an integration method that integrates the amount of current per predetermined time of charging current and discharging current to the battery, respectively. and the integrated value of the charging current amount is subtracted from the integrated value of the discharging current amount obtained by the integrating unit to obtain the battery.
a remaining capacity detection unit that detects the remaining capacity of the battery; and a warning that the capacity of the battery has decreased when the remaining capacity of the battery detected by the remaining capacity detection unit reaches a predetermined set capacity. A DC power supply device characterized by having an abnormality diagnosis circuit equipped with a battery capacity reduction alarm output section that performs the following. 2. A power supply unit that rectifies AC power into DC power and supplies it as DC power to a plurality of control units in the plant, and is charged by surplus current from this power supply unit, and is charged when the output of this power supply unit decreases or In a DC power supply device comprising a battery that supplies DC power to the control unit when the load on the control unit increases, an integration method that integrates the amount of current per predetermined time of charging current and discharging current to the battery, respectively. and comparing the integrated value of the discharge current amount obtained by the integration unit with the integrated value of the charging current amount, and if the integrated value of the discharge current amount is large and this integrated value is equal to or greater than a preset value, A DC power supply device comprising an abnormality diagnostic circuit including a battery discharge continuation alarm output section that outputs a battery discharge continuation alarm output section. 3. A power supply unit that rectifies AC power into DC power and supplies it as DC power to a plurality of control units in the plant; and a power supply unit that is charged by surplus current from this power supply unit and is charged when the output of this power supply unit decreases or A DC power supply device comprising: a battery that supplies DC power to the control unit when the load on the control unit increases; a voltage change rate detection unit that detects a voltage change rate of the battery voltage per predetermined time; A DC power supply device comprising an abnormality diagnostic circuit including a battery voltage drop alarm output unit that issues an alarm for a decrease in battery voltage when the voltage change rate detection unit detects a rate of change in a decreasing direction. 4. A power supply unit that rectifies AC power into DC power and supplies it as DC power to a plurality of control units in the plant, and is charged by surplus current from this power supply unit, and is charged when the output of this power supply unit decreases or A DC power supply device comprising a battery that supplies DC power to the control unit when the load on the control unit increases, detecting the voltage of the battery;
A DC power supply device comprising an abnormality diagnostic circuit including a battery voltage drop alarm output section that issues an alarm for a voltage drop in the battery when the battery voltage reaches a predetermined set voltage. 5. A power supply unit that rectifies AC power into DC power and supplies it as DC power to a plurality of control units in the plant, and is charged with surplus current from this power supply unit, and is charged when the output of this power supply unit decreases or In a DC power supply device comprising a battery that supplies DC power to the control unit when the load on the control unit increases, the DC power required by the control unit is less than or equal to the rated DC power supplied from the power supply unit. In this case, if the battery continues to be discharged, the DC power supply device includes an abnormality diagnostic circuit including a power supply abnormality alarm output unit that issues an alarm of abnormality in the power supply unit.