JP2013081337A - Dc power feeding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power feeding system equipped with a semiconductor breaker, capable of continuously operating the system stably and improving reliability of the system even when an accident due to short-circuit or the like occurs in a load device.SOLUTION: Respective load side semiconductor breakers 11-1, .. of a DC power feeding system 1 repeat a retry operation when a current flowing in a semiconductor switch section 19 is determined to be an overcurrent as well as continuously turning off the semiconductor switch section 19 when the retry operation is performed a second retry frequency. A power supply side semiconductor breaker 10 of the DC power feeding system 1 repeats retry operation when a current flowing in a semiconductor switch section 16 is determined to be an overcurrent, and causes the semiconductor switch means 16 to be continuously turned off when retry operations are performed retry times more than respective retry times in all load side semiconductor breakers 11-1, .. in a state determined as the overcurrent.

Description

  The present invention relates to a DC power supply system including a semiconductor circuit breaker capable of interrupting an overcurrent that flows from a power supply device to a load device.

  In recent years, in data centers, communication stations, and the like, construction of a DC power supply system that supplies DC power to various load devices such as routers and servers has been promoted. The DC power supply system supplies DC power (DC current) from a power supply device to a load device via a power supply line. When supplying power from one power supply device to a plurality of load devices, the power supply device The direct current power is distributed by a current distribution device and supplied to a plurality of load devices.

  In such a DC power supply system, it is required to supply power to the load device with high reliability and high quality. For this reason, a protection device is provided between the power supply device and the load device in order to protect the system from an excessive short-circuit current that occurs when an accident such as a short circuit occurs on the load device side. In a system including the above-described current distribution device, a protection device is generally provided for each distribution destination in the current distribution device.

  As a protection device, a fuse has been generally used. However, in the case of a fuse, it is necessary to replace it every time it is blown by overcurrent, or when a high-voltage DC power supply system is used, a fuse with a rating corresponding to that is required. There is a difficulty in terms of labor and cost, such as the need to use it. Therefore, various semiconductor circuit breakers have been proposed as a protection device that replaces the fuse, in which a semiconductor switching element is inserted on the power supply line, and the power supply line can be turned on and off by the semiconductor switching element.

  The semiconductor circuit breaker always turns on the semiconductor switching element during normal operation to supply power from the power supply device to the load device. For example, a short circuit accident occurs and the current flowing through the semiconductor switching element exceeds a predetermined threshold value. In this case, that is, when an overcurrent state is reached, this is detected and the semiconductor switching element is turned off to cut off the overcurrent.

  By the way, the occurrence of overcurrent is not limited to the case where a short circuit accident occurs. For example, an overcurrent may occur even if the DC power supply system is normal, such as an instantaneous inrush current or noise.

  Such an overcurrent due to an inrush current or noise is not caused by a system abnormality, unlike an accident current due to a short circuit or the like. Therefore, when such an overcurrent is detected, it is not always continuous. There is no need to shut off.

  Therefore, in the past, when an overcurrent occurred, it was determined whether it was an accidental current due to a short circuit or a temporary one due to an inrush current or noise. There is known a technique of turning it off (for example, see Patent Documents 1 and 2).

The techniques described in Patent Documents 1 and 2 determine whether or not the current flowing through the semiconductor switching element is equal to or greater than a threshold value. If the current exceeds the threshold value, the semiconductor switching element is turned on / off (hereinafter referred to as “retry operation”). Is used to limit the short-circuit current. Each time the retry operation is performed, that is, every time the power is turned off and then turned on again, it is determined whether or not the current is below the threshold value by looking at the current passing through the semiconductor switching element when the power is turned on. Then, the retry operation is repeated until the value falls below the threshold value, and if the value falls below the threshold value, the retry operation is stopped and the semiconductor switching element is always returned to the on state.

  On the other hand, if the threshold value is not less than the threshold value after repeating the retry operation for a predetermined time, it is determined that the accident current is caused by a short circuit or the like, and the semiconductor switching element is completely turned off.

JP 2007-236061 A Japanese Patent Laid-Open No. 11-41787

  By the way, depending on how the system is designed, as shown in FIG. 5, the configuration of the DC power supply system includes one power supply device 103 and one semiconductor circuit breaker connected to the power supply device 103 (upper semiconductor breaker). ) 110, each semiconductor circuit breaker (lower semiconductor circuit breaker) 111-1 to 111-N (N is an integer of 1 or more) connected to the upper semiconductor circuit breaker 110, and the lower semiconductor circuit breaker 111 The form provided with each load apparatus 151-1 to 151-N connected to each of -1 to 111-N can be considered.

In general, the current threshold value (first threshold value) of the upper semiconductor circuit breaker 110 is set to a value larger than the current threshold values (second threshold value) of the lower semiconductor circuit breakers 111-1 to 111 -N.
The upper semiconductor circuit breaker 110 is a short circuit current that is mainly generated when an accident such as a short circuit from the output side of the upper semiconductor circuit breaker 110 to the input of the lower semiconductor circuit breakers 111-1 to 111-N occurs. It has a function to protect the system from (overcurrent).

  The lower level semiconductor circuit breakers 111-1 to 111-N are mainly accidents such as short circuits on the load devices 151-1 to 151-N connected to the lower level semiconductor circuit breakers 111-1 to 111-N. Has a function of protecting the system from a short-circuit current (overcurrent) that occurs when a fault occurs.

  The retry operation of the upper semiconductor circuit breaker 110 and the lower semiconductor circuit breakers 111-1 to 111-N is set to perform the same operation except that the current threshold value that triggers the retry operation is different. It is normal.

  In the DC power supply system of the above-described form, for example, when a short-circuit accident occurs in the load device 151-1, the short-circuit current is not limited to the lower semiconductor breaker 111-1 but also to the semiconductor breaker 110 located in the higher rank. Also flows. This is because the current value of this short-circuit current is extremely large and often exceeds the first threshold value of the upper semiconductor breaker 110.

For this reason, if the lower semiconductor breaker 111-1 and the upper 110 start retry operations at the same time and the short-circuit accident continues even after performing the retry operation for a predetermined time, both the semiconductor breakers 111-1, 110 These semiconductor switching elements are continuously turned off at the same time.

  Accordingly, not only the lower semiconductor breaker 111-1 but also the upper semiconductor breaker 110 is protected (referred to as an operation that continuously cuts off the power supply from the power supply device to the load device, hereinafter referred to as “breaking operation”). Will work).

Therefore, the entire DC power supply system goes down.
The present invention has been made in view of the above problems, and includes a semiconductor circuit breaker capable of continuously operating the system stably and improving the reliability of the system even when an accident due to a short circuit or the like occurs in the load device. An object is to provide a direct current power supply system.

  The invention according to claim 1, which has been made to solve the above problem, distributes DC power from a power supply device to a plurality of power supply systems, and supplies DC power to a plurality of load devices for each power supply system, From the power supply side semiconductor circuit breaker connected to each load device, the power supply side semiconductor circuit breaker for conducting / cutting off the first power supply line connected to the power supply device and through which the direct current from the power supply device flows. And a plurality of load-side semiconductor circuit breakers for conducting / cut-off the second power supply line through which the direct current flows through the plurality of load-side semiconductor circuit breakers. First semiconductor switch means for conducting / interrupting the second power supply line by turning on / off, and a first overcurrent determining circuit for determining whether or not the direct current flowing through the first semiconductor switch means is an overcurrent. Current When the overcurrent is determined by the disconnection means and the first overcurrent determination means, a load-side retry operation is performed to repeatedly turn on and off the first semiconductor switch means at a predetermined timing. And a first retry control means for continuously turning off the first semiconductor switch means when the state judged as the overcurrent by one overcurrent judgment means continues for a load side accident determination required period or longer. The power-supply-side semiconductor circuit breaker includes a second semiconductor switch means for conducting / cutting off the first power supply line by turning on / off the switch, and a direct current flowing through the second semiconductor switch means is an overcurrent. A second overcurrent judging means for judging whether or not there is the second semiconductor current at the predetermined timing when the second overcurrent judging means judges the overcurrent. A power supply-side retry operation that repeatedly turns on and off the switch means, and the load-side faults in all the load-side semiconductor circuit breakers are in a state that is judged as the overcurrent by the second overcurrent judging means. A second retry control means is provided for continuously turning off the second semiconductor switch means when the power-supply side accident determination required period is longer than the determination required period.

  In the present invention, when an overcurrent (short-circuit current) flows to the first semiconductor switch means and the second semiconductor switch means due to a short-circuit accident of the load device, the short-circuit accident does not occur until the load-side accident determination required period elapses. Although the load-side retry operation of the load-side semiconductor circuit breaker (low-order semiconductor circuit breaker) connected to the generated load device continues, the first semiconductor switch means is continuously turned off when the load-side accident determination time period elapses. The

Since the power-side accident determination required period is longer than the load-side accident determination required period, the second semiconductor switch means is not turned off simultaneously with the lapse of the load-side accident determination required period.
In addition, after the load side accident determination required period has elapsed, the short circuit current does not flow to the second semiconductor switch means, and the power supply side circuit breaker stops the power supply side retry operation. ) Returns to a normal state (a state in which the second semiconductor switch means is kept on).

  For this reason, according to the semiconductor circuit breaker of claim 1, even if the breaking operation works on the lower semiconductor breaker due to the short circuit accident of the load device, the breaking operation does not work on the upper semiconductor breaker and the normal state is restored. Therefore, the entire system does not go down except for the lower-order semiconductor circuit breaker connected to the load device in which the short circuit accident has occurred.

Therefore, even when an accident such as a short circuit occurs in the load device, the system can be continuously operated stably and the reliability of the system can be improved.
According to a second aspect of the present invention, the DC power from the power supply device is supplied to one load device, and the first power supply line connected to the power supply device and through which the DC current from the power supply device flows is electrically connected. One power supply side semiconductor circuit breaker for cutting off, and one load side semiconductor circuit breaker for conducting / cutting off a second power supply line connected to the load device and through which a direct current from the power supply side semiconductor circuit breaker flows The load-side semiconductor circuit breaker comprises: a first semiconductor switch means for conducting / interrupting the second power supply line by turning on / off the switch; and the first semiconductor switch means. A first overcurrent determination means for determining whether or not the direct current flowing through the semiconductor switch means is an overcurrent; and when the overcurrent is determined by the first overcurrent determination means, at a predetermined timing. Said first half A load-side retry operation that repeats on / off of the body switch means, and the first overcurrent judgment means determines that the overcurrent has continued for a load-side accident judgment required period or longer. A second semiconductor switch having first retry control means for continuously turning off the semiconductor switch means, wherein the power supply side semiconductor circuit breaker conducts and cuts off the first power supply line by turning on and off the switch; And the second overcurrent determination means for determining whether or not the direct current flowing through the second semiconductor switch means is the overcurrent, and the second overcurrent determination means determines the overcurrent. In this case, a power supply-side retry operation that repeatedly turns on and off the second semiconductor switch means at the predetermined timing is performed, and the second overcurrent determination means And second retry control means for continuously turning off the second semiconductor switch means when a state determined as current continues for a power-side accident determination required period longer than the load-side accident determination required period. Configured.

  A DC power supply system according to the present invention includes a power supply device, one power supply side semiconductor circuit breaker connected to the power supply device, one load side semiconductor circuit breaker connected to the power supply side semiconductor circuit breaker, and the load It is composed of one load device connected to the side semiconductor circuit breaker, and there is one power feeding system.

  Therefore, in view of the fact that there is only one power supply system and that the shut-down operation works for the lower-level semiconductor circuit breaker and that the upper-level semiconductor circuit breaker does not work and returns to the normal state, a short-circuit accident occurs in the load device. It becomes easy to specify that.

  According to a third aspect of the present invention, the apparatus may further include a setting device, and the setting device may include a setting unit that sets the load-side accident determination required period and the power-side accident determination required period.

  Therefore, it is possible to easily change and update the settings of the load-side accident determination required period of the load-side semiconductor circuit breaker and the power-side accident determination required period of the power-side semiconductor circuit breaker, so that the system setting can be easily changed. , The flexibility of system setting is expanded.

  Further, according to a fourth aspect of the present invention, the load side accident determination required period is a period until a load side accident determination time elapses or a period in which the load side retry operation is performed for the load side retry count, The side accident determination required period is a period until the power-side accident determination time longer than the load-side accident determination time elapses, or a period during which the power-side retry operation is performed more times than the load-side retry count It is desirable that

  By doing in this way, the freedom degree of the setting of an accident determination required period spreads, and it becomes possible to provide a highly versatile DC power supply system.

It is a lineblock diagram showing a schematic structure of a direct-current power supply system of a 1st embodiment. (A) is a figure for demonstrating operation | movement of the load side semiconductor circuit breaker when a short circuit current flows, (b) is for demonstrating operation | movement of the power supply side semiconductor circuit breaker when a short circuit current flows. FIG. (A) is a waveform diagram of an output current flowing through a semiconductor switch section of a load-side semiconductor circuit breaker, (b) is a waveform diagram of a gate drive voltage of a semiconductor switch section of the load-side semiconductor circuit breaker, and (c) is a power supply It is the output current waveform figure which flows into the semiconductor switch part of a side semiconductor circuit breaker, (d) is the figure which showed the waveform of the gate drive voltage of the semiconductor switch part of a power supply side semiconductor circuit breaker. It is the figure which showed the modification of the DC power supply system of this invention. It is a figure for demonstrating the conventional DC power supply system.

Preferred embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
(1) Configuration of DC Power Supply System FIG. 1 shows a schematic configuration of a DC power supply system 1 according to an embodiment to which the present invention is applied. As shown in FIG. 1, the DC power supply system 1 of the present embodiment distributes DC power from the power supply device 3 to a plurality of power supply systems, and a plurality of load devices 51-1 and 51-2 are provided for each power supply system. , 51-3
,... Are configured to supply DC power. FIG. 1 shows a configuration in which one load device is connected to one system as an example.

The DC power supply system 1 is arranged at the rear stage of a power source side semiconductor circuit breaker (upper semiconductor circuit breaker) 10 and a power source side semiconductor circuit breaker 10 for conducting / cutting off the first power supply lines 7, 8. Are connected to the devices 51-1, 51-2, 51-3,.
A plurality of load-side semiconductor circuit breakers (low-order semiconductor circuit breakers) 51-1 for conducting and breaking 13
, 51-2, 51-3,...

The power supply device 3 supplies DC power for the operation to each of the load devices 51-1, 51-2, 51-3,. As a specific configuration of the power supply device 3, for example, a configuration including a rectifier that converts commercial AC power into DC power is conceivable. However, as long as DC power of a predetermined voltage can be supplied to the load device side. The specific configuration is not particularly limited.

Each of the load devices 51-1, 51-2, 51-3,... Operates by DC power from the power supply device 3.
The power supply side semiconductor circuit breaker 10 flows through the semiconductor switch unit 16 provided in one of the two power supply lines 7 and 8 and the power supply line 7 provided with the semiconductor switch unit 16. A current sensor 15 for detecting current and a control circuit 23 for controlling the operation (on / off) of the semiconductor switch unit 16 based on the detection result by the current sensor 15 are provided.

  Of the two power supply lines 7, 8, one power supply line 7 provided with the semiconductor switch unit 16 is connected to the positive side of the DC power supply (DC voltage) in the power supply device 3, and the other power The supply line 8 is connected to the negative electrode side of the DC power supply in the power supply device 3. However, there is no particular limitation as to which of the power supply lines 7 and 8 the semiconductor switch unit 16 or the current sensor 15 is provided, and the semiconductor switch unit 16 is connected to the load device 51-1 by direct current power. As long as the current sensor 15 can supply or shut off the current sensor 15 and the current sensor 15 can detect the current flowing to the load device side 51-1, the specific power supply line is determined as appropriate. be able to.

  The semiconductor switch unit 16 includes a semiconductor switching element (not shown, for example, a MOSFET) inserted on the power supply line 7, and a drive signal from the control circuit 23 (from a drive unit 24 described later in detail). The semiconductor switching element is turned on / off according to the drive signal). That is, when the semiconductor switching element is, for example, a MOSFET and the semiconductor switch unit is provided on the positive electrode side, the drain is connected to the power supply device 3 side, the source is connected to the load device 51-1 side, and the gate is connected to the drive unit 24. Then, the drive signal from the drive unit 24 is input to the gate.

  In the following description, when the semiconductor switch unit 16 is referred to as “on” or “off”, it means in detail “on (turn on)” or “off (turn off)” of the semiconductor switching elements constituting the semiconductor switch unit 16. It shall be.

  Therefore, while the semiconductor switch unit 16 is turned on, the power supply line 7 provided with the semiconductor switch unit 16 is conducted. In other words, power can be supplied from the power supply device 3 to the load device 51-1. Conversely, while the semiconductor switch unit 16 is turned off, the power supply line 7 provided with the semiconductor switch unit 16 is cut off. That is, the power supply from the power supply device 3 to the load device 51-1 is cut off.

  The control circuit 23 measures a current value detected by the current sensor 15 and outputs data (current Ia) indicating the current value, and data (current Ia) output from the current measurement unit 21. ) Is stored, and various determinations to be described later are performed based on the current Ia stored in the measurement value storage unit 22, and the semiconductor switch unit 16 is turned on or off according to the determination result. A control unit 26 that outputs a control signal of the control unit 26, a drive unit 24 that turns on and off the semiconductor switch unit 16 by outputting a drive signal to the semiconductor switch unit 16 according to the control signal from the control unit 26, and a control unit 26 And a setting information storage unit 25 in which various setting information used for various determinations to be made is stored.

  The setting information storage unit 25 includes, as setting information, a “first overcurrent threshold value” used as a determination criterion for determining whether or not the overcurrent flowing through the semiconductor switch unit 16 is an accident current due to a short circuit or the like. As a criterion for determining whether or not the semiconductor switch unit 16 is to be continuously turned off when the overcurrent flowing through the semiconductor switch unit 16 is determined to be an accident current due to a short circuit or the like and the state continues. The “first retry count” used is stored. Here, the “first retry count” is the number of retry operations of the power supply side circuit breaker 10 described later. Note that the first retry count is set to be larger than a second retry count described later.

  The setting information is input / stored in the setting information storage unit 25 from, for example, the external setting device 70 via the network (for example, LAN) 60 and the input interface 14. These pieces of setting information are updated as appropriate according to changes in system settings.

  Note that the measurement of the current Ia by the current measuring unit 21 is performed according to a measurement instruction from the control unit 25. Further, during the retry operation, a measurement instruction is given so as to measure the current Ia (peak value) when the semiconductor switch unit 16 is turned on. Each time measurement is performed according to the measurement instruction, the current Ia as the measurement result is stored in the measurement value storage unit 42.

  The current distribution device 9 is connected to the subsequent stage of the power supply side semiconductor circuit breaker 10, and distributes and supplies the DC power from the power supply device 3 to each load device 51-1, 51-2, 51-3,. It is provided to do.

  This current distribution device 9 detects an overcurrent flowing to the load devices 51-1, 51-2, 51-3,... In each distributed system and interrupts it as necessary. For this purpose, load-side semiconductor circuit breakers 11-1, 11-2, 11-3,... Are provided.

  In the DC power supply system 1 of the present embodiment, an overcurrent larger than the rated current may occur in each of the systems described above. Here, as an overcurrent, for example, an inrush current, a short circuit current continuously generated by an accident such as a short circuit on the load devices 51-1, 51-2, 51-3,.

  In the present embodiment, one load-side semiconductor circuit breaker 11-1 is provided in the system to one load device 51-1 among the plurality of load devices 51-1, 51-2, 51-3,. One load-side semiconductor circuit breaker 11-2 is also provided in the system to another load device 51-2, and one load side is also provided in the system to another load device 51-3. A semiconductor circuit breaker 11-3 is provided.

  In the present embodiment, since the plurality of load-side semiconductor circuit breakers 11-1, 11-2, 11-3,... The configuration of one load-side semiconductor circuit breaker 11-1 will be described as follows.

  The load-side semiconductor circuit breaker 11-1 includes a semiconductor switch unit 19 provided in one of the two power supply lines 12 and 13, and the power supply line 12 provided with the semiconductor switch unit 19. And a control circuit 33 that controls the operation (on / off) of the semiconductor switch unit 19 based on the current detected by the current sensor 18. .

  Of the two power supply lines 12, 13, one power supply line 12 provided with the semiconductor switch unit 19 is connected to the positive side of the DC power supply (DC voltage) in the power supply device 3, and the other power The supply line 13 is connected to the negative electrode side of the DC power supply in the power supply device 3.

  The semiconductor switch unit 19 includes a semiconductor switching element (not shown; for example, MOSFET) inserted on the power supply line 12, and the semiconductor switching element is turned on / off according to a drive signal from the control circuit 33. Is done.

  For this reason, while the semiconductor switch unit 19 is turned on, the power supply line 12 provided with the semiconductor switch unit 19 is conducted. On the contrary, while the semiconductor switch unit 19 is turned off, the power supply line 12 provided with the semiconductor switch unit 19 is cut off. Here, for example, when a short-circuit accident occurs in the load device immediately 51-1, a short-circuit current flows through the power supply lines 7 and 12 when the semiconductor switch units 16 and 19 are on.

  The control circuit 33 measures a current value detected by the current sensor 18 and outputs data (current Ib) indicating the current value, and data (current Ib) output from the current measurement unit 41. ) Is stored, and various determinations to be described later are performed based on the current Ib stored in the measurement value storage unit 42, and the semiconductor switch unit 19 is turned on or off according to the determination result. A control unit 43 that outputs a control signal of the control unit 43, a drive unit 44 that turns on and off the semiconductor switch unit 19 by outputting a drive signal to the semiconductor switch unit 19 according to the control signal from the control unit 43, and a control unit 43 And a setting information storage unit 45 in which various setting information used for various determinations to be made is stored.

  In the setting information storage unit 45, as setting information, a “second overcurrent threshold” used as a determination criterion for determining whether or not the overcurrent flowing through the semiconductor switch unit 19 is an accident current due to a short circuit or the like. When the overcurrent flowing through the semiconductor switch unit 19 is determined to be an accident current due to a short circuit or the like, and the state continues, as a criterion for determining whether or not the semiconductor switch unit 19 is continuously turned off The “second retry count” used is stored. Here, the “second retry count” is the number of retry operations of load-side semiconductor circuit breakers 51-1, 51-2, 51-3,.

The setting information is input / stored in the setting information storage unit 45 from the external setting device 70 via the network (LAN) 60 and the input interface 34-1. In addition, these setting information are updated as appropriate in accordance with a system design change.

  Note that the measurement of the current Ib by the current measurement unit 41 is performed according to a measurement instruction from the control unit 43. During the retry operation, a measurement instruction is issued so as to measure the current Ib (peak value) when the semiconductor switch unit 19 is turned on. Each time measurement is performed according to the measurement instruction, the current Ib as the measurement result is stored in the measurement value storage unit 42.

(2) Description of operation of the power supply side semiconductor circuit breaker and the load side semiconductor circuit breaker First, the power supply side semiconductor circuit breaker 10 and the load side semiconductor circuit breakers 11-1, 11-2, 11-3 configured as described above. The retry operation and the setting of the number of retries will be described with reference to FIG. In the present embodiment, the plurality of load-side semiconductor circuit breakers 11-1, 11-2, 11-3,... Provided in the current distribution device 9 basically perform the same operation. The operation of one load-side semiconductor circuit breaker 11-1 will be described as a representative.

  FIG. 2A is a diagram for explaining the operation of the load-side semiconductor circuit breaker 11-1 when a short-circuit current flows through the semiconductor switch unit 19, and shows an output current waveform flowing through the semiconductor switch unit 19. FIG. 2B is a diagram for explaining the operation of the power supply side semiconductor circuit breaker 10 when a short-circuit current flows through the semiconductor switch unit 16, and shows an output current waveform flowing through the semiconductor switch unit 16.

  3A is the same diagram as FIG. 2A, and FIG. 3B is a diagram showing the waveform of the gate drive voltage of the semiconductor switch section 19 of the load-side semiconductor circuit breaker. ). 3C is the same diagram as FIG. 2B, and FIG. 3D is a diagram showing the waveform of the gate drive voltage of the semiconductor switch unit 16 of the power supply side semiconductor circuit breaker 10, and FIG. It is a figure corresponding to c).

  Further, the first overcurrent threshold and the second overcurrent threshold are set to values smaller than the current value of the short circuit current, and basically the first overcurrent threshold is equal to or greater than the second overcurrent threshold. It is set to be. In the present embodiment, the first overcurrent threshold and the second overcurrent threshold are assumed to be the same for convenience.

First, operation | movement of the load side semiconductor circuit breaker 11-1 is demonstrated.
As shown in FIG. 2A, in a steady state (period A1), when a short-circuit current larger than the second overcurrent threshold flows through the semiconductor switch unit 19 (time t = 0), the control unit 43 causes the semiconductor to By outputting a control signal for performing the retry operation of the switch unit 19 (hereinafter referred to as “load-side retry operation”) to the drive unit 44 and performing the retry operation, the load device 51 is provided via the semiconductor switch unit 19. The current flowing to the -1 side is limited.

  Here, as shown in FIG. 2A, the load-side retry operation repeatedly turns on / off the semiconductor switch unit 19 at every predetermined timing. Each time the semiconductor switch unit 19 is turned on, a current flowing through the semiconductor switch unit 19 is detected when the semiconductor switch unit 19 is turned on, and it is determined whether or not the detected current is equal to or greater than a second overcurrent threshold. And when it is less than a 2nd overcurrent threshold value, load side retry operation stops and it returns to a steady state. As long as it is equal to or greater than the second overcurrent threshold, the load-side retry operation is continuously repeated for the second retry count (four times in this example) stored in the setting information storage unit 45.

When the number of retries in the load side retry operation is equal to or greater than the second retry number and the detected current is equal to or greater than the second overcurrent threshold, the load side retry operation is stopped (FIG. 2A). T = t ₁ ) The semiconductor switch unit 19 is continuously turned off.

  In addition, you may use 2nd accident determination time instead of using the 2nd retry frequency as determination criteria. In this case, if the second overcurrent threshold is exceeded even after the second accident determination time has elapsed since the load-side retry operation started, the load-side retry operation is stopped and the semiconductor switch unit 19 is continued. Turn off.

Next, the operation of the power supply side semiconductor circuit breaker 10 will be described.
As shown in FIG. 2B, in a steady state (period A2), when a short-circuit current larger than the first overcurrent threshold flows through the semiconductor switch unit 16 (time t = 0), the control unit 23 operates as a semiconductor. By outputting a control signal for performing the retry operation of the switch unit 16 (hereinafter referred to as “power supply side retry operation”) to the drive unit 24 and performing the power supply side retry operation, the load is transmitted via the semiconductor switch unit 16. The current flowing to the side semiconductor circuit breaker 11-1 side is limited.

  Each time the semiconductor switch unit 16 is turned on, a current flowing through the semiconductor switch unit 16 is detected when the semiconductor switch unit 16 is turned on, and it is determined whether or not the detected current is greater than or equal to a first overcurrent threshold. Then, when the detected current is less than the first overcurrent threshold, the power supply side retry operation is stopped and returned to the steady state. The side retry operation is repeated for the first retry count (9 times in this example) stored in the setting information storage unit 25.

When the number of retries in the power supply side retry operation is equal to or greater than the first retry number and the detected current is greater than or equal to the first overcurrent threshold, the power supply side retry operation is stopped (FIG. 2B). T = t ₂ ) The semiconductor switch unit 16 is continuously turned off.

  When the current flowing through the semiconductor switch unit 16 becomes less than the first overcurrent threshold, the control unit 26 stops the power supply side retry operation and continuously turns on the semiconductor switch unit 16. Thereafter, the current flowing through the semiconductor switch unit 16 returns to a steady state.

Next, the basic operation of the control unit 43 of the load side semiconductor circuit breaker 11-1 will be described.
First, the control unit 43 of the load-side semiconductor circuit breaker 11-1 turns on the semiconductor switch unit 19 when the supply of steady DC power from the power supply device 3 is started. Next, a counter (not shown) in the control unit 43 is initialized.

Next, it is determined whether or not the measured current Ib is equal to or greater than a second overcurrent threshold (second overcurrent threshold determination process). If the measured current Ib is equal to or greater than the second overcurrent threshold, the semiconductor switch unit 19 is turned off. .
Next, it is determined whether or not the counter value is equal to or greater than a preset second retry count (four in this example) (first retry count determination process).

Next, when the counter value is less than a preset second retry count (4 in this example), the load-side retry operation is started after a predetermined period of time (for example, after 100 μs) ( The semiconductor switch unit 19 is turned on). Thereafter, the counter value is increased by +1, and the process returns to the second overcurrent threshold determination process.

  After returning to the second overcurrent threshold determination process, the counter value is incremented from the second overcurrent threshold determination process until the counter value is increased until the counter value reaches the preset second retry count. The process is repeated.

When the value of the counter is equal to or greater than a preset second retry count (four times in this example), the semiconductor switch unit 19 is continuously turned off.
The determination process is executed based on a predetermined program stored in storage means (for example, ROM) in the control unit 43.

  In addition, about operation | movement of the control part 26 of the power supply side semiconductor circuit breaker 10 after the supply of the regular direct-current power from the power supply device 3 is started, the control part 43 of the load side semiconductor circuit breaker 11-1 mentioned above is described. Since it is the same as the operation, its description is omitted.

  In the following, when a short circuit accident occurs in any of the load devices 51-1, 51-2, 51-3,... (In this example, the load device 51-1), a short circuit accident occurs. The operation of the load side semiconductor circuit breaker 11-1 and the power source side semiconductor circuit breaker 10 connected to the load device 51-1 will be described.

In this example, the current Ib is the second overcurrent when the counter value of the counter in the control unit 43 of the load-side semiconductor circuit breaker 11-1 exceeds the second retry count (four times in this example). Since it is equal to or greater than the threshold value, the CPU in the control unit 43 stops the load side retry operation (time t = t _{1 in} FIG. 3A) and continuously turns off the semiconductor switch unit 19.

  Here, if the first retry count of the power-side semiconductor breaker 10 and the second retry count of the load-side semiconductor breaker 11-1 are the same, the power-side retry is performed simultaneously with the stop of the load-side retry operation. The operation is also stopped, and both the semiconductor switch sections 16 and 19 are continuously turned off. For this reason, the entire DC power supply system goes down.

  However, in this example, the first retry count (9 times in this example) of the power supply side semiconductor circuit breaker 10 is larger than the second retry number (4 times in this example) of the load side semiconductor circuit breaker 11-1. Therefore, even if the period for which the second retry count is performed elapses, the power supply side retry operation continues and the semiconductor switch unit 16 does not turn off.

After the period in which the second retry count is performed (after time t = t _{3 in} FIG. 3C),
A current does not flow through the semiconductor switch unit 19, and a steady current flows through the semiconductor switch unit 16. Since the steady current flowing in the semiconductor switch unit 16 is less than the first overcurrent threshold (see FIG. 3C), the power supply side circuit breaker 10 stops the power supply side retry operation, and the power supply side semiconductor circuit breaker 10 The state returns to the normal state (the state in which the second semiconductor switch means is kept on (see FIG. 3D)).

  For this reason, the lower load side connected to the load device in which the short circuit accident has occurred due to the short circuit accident of at least one of the load devices 51-1, 51-2, 51-3,. Even if the circuit breaker operates, the upper power supply side semiconductor circuit breaker does not operate and returns to the normal state.Therefore, except for the lower circuit breaker connected to the load device where the short circuit accident occurred, the DC The entire power supply system will not go down.

Therefore, even when an accident such as a short circuit occurs in the load device, the system can be continuously operated stably and the reliability of the system can be improved.
Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments, and can take various forms as long as they belong to the technical scope of the present invention. Needless to say.

[Modification 1]
For example, in the first embodiment, when the state in which an accident current due to a short circuit or the like continues to flow through the semiconductor switch units 16 and 19 is determined (hereinafter referred to as “the semiconductor switch units 16 and 19 are continuously turned off”). In the above description, the number of retries is used as a criterion for performing the “off determination”. As the criterion, the time (accident determination time) from when the retry operation is started until a predetermined time elapses is described. It may be used. The "accident determination time" of the upper power supply side semiconductor circuit breaker 10 is greater than any "accident determination time" of each of the lower load side semiconductor circuit breakers 51-1, 51-2, 51-3,. It is set to be long.

[Modification 2]
In addition, as a determination criterion for performing the above-described OFF determination of the power supply side semiconductor circuit breaker and the load side semiconductor circuit breaker, the “retry count” is used for either one of the power supply side semiconductor circuit breaker and the load side semiconductor circuit breaker. The other may be performed using “accident determination time”. It should be noted that the time corresponding to the “retry count” of the upper power supply side semiconductor circuit breaker 10 or the “accident determination time” is that of each of the lower load side semiconductor circuit breakers 51-1, 51-2, 51-3,. It is set to be longer than the time corresponding to any “number of retries” or “accident determination time”.

[Modification 3]
Further, the DC power supply system 1 according to the first embodiment described above includes one power supply device 3, one power supply side semiconductor circuit breaker (upper semiconductor breaker) 10 connected to the power supply device 3, and the power supply A plurality of load-side semiconductor circuit breakers (lower semiconductor circuit breakers) 11-1, 11-2,... Connected to the side semiconductor circuit breaker 10, and the load-side semiconductor circuit breakers 11-1, 11-2,. Are each provided with load devices 51-1, 51-2,.

  However, the present invention is not limited to the above-described configuration. For example, as illustrated in FIG. 4, the DC power supply system 80 includes one power supply device 3 and a plurality of power supplies connected to the power supply device 3. .., And a plurality of power supply side semiconductor circuit breakers 10-1, 10-2,. , Lower current distribution devices 9-1, 9-2,...

  Specifically, as shown in FIG. 4, the lower-order current distribution device 9-1 includes load-side semiconductor circuit breakers (lower-order semiconductor circuit breakers) 11-1 to 11 connected to the power-side semiconductor circuit breaker 10-1. -N (N is an integer of 2 or more). The lower-order current distribution device 9-2 includes load-side semiconductor circuit breakers (lower-order semiconductor circuit breakers) 20-1 to 20-N (N is an integer of 2 or more) connected to the power supply-side semiconductor circuit breaker 10-2. Configured.

  Load devices 51-1 to 51-N (N is an integer of 2 or more) are connected to the load-side semiconductor circuit breakers (lower-order semiconductor circuit breakers) 11-1 to 11-N, respectively. Load devices 52-1 to 52-N (N is an integer of 2 or more) are connected to the devices (lower semiconductor circuit breakers) 20-1 to 20-N, respectively.

[Modification 4]
In the first embodiment described above, the load-side semiconductor circuit breakers are provided in all of the plurality of systems distributed by the current distribution device 9, but this is an example, and the semiconductor circuit breakers are not necessarily provided in all the systems. There is no need to provide it.

[Modification 5]
In the first embodiment, the DC power supply system 1 configured to distribute DC power from the power supply device 3 to a plurality of systems by the current distribution device 9 has been described. Needless to say, the present invention can also be applied to a DC power supply system of a system.

DESCRIPTION OF SYMBOLS 1,80 ... DC power supply system, 3 ... Power supply device, 7, 8 ... Power supply line (1st power supply line), 9 ... Current distribution device, 10 ... Power supply side semiconductor circuit breaker, 11-1, 11-2 , 11-3 ... load side semiconductor circuit breaker, 12, 13 ... power supply line (second power supply line), 51-1, 51-2, 51-3 ... load device, 15, 18 ... current sensor, 16 ... Semiconductor switch part (second semiconductor switch means), 19 ... Semiconductor switch part (first semiconductor switch means), 21, 41 ... Current measurement part, 22, 42 ... Measurement value storage part, 23 ... Control circuit (first 2, retry control means), 24, 44... Drive section, 25, 45... Setting information storage section, 26... Control section (second overcurrent determination means), 33... Control circuit (first retry control means), 34-1, 34-2, 34-3 ... input interface, 43 ... control Part (a first overcurrent determination means)

Claims (4)

DC power from a power supply device is distributed to a plurality of power supply systems, DC power is supplied to a plurality of load devices for each power supply system, and a DC current from the power supply device is connected to the power supply device. A power supply side semiconductor circuit breaker for conducting / cutting off the power supply line, and a second power supply line connected to each of the load devices and through which a direct current from the power supply side semiconductor circuit breaker flows are conducted / cut off. A DC power supply system including a plurality of load-side semiconductor circuit breakers,
Each of the plurality of load-side semiconductor circuit breakers is
First semiconductor switch means for conducting / interrupting the second power supply line by turning on / off the switch;
First overcurrent determination means for determining whether or not a direct current flowing through the first semiconductor switch means is an overcurrent;
When the first overcurrent determination unit determines that the overcurrent is present, a load-side retry operation that repeats on / off of the first semiconductor switch unit at a predetermined timing is performed, and the first overcurrent is performed. A first retry control means for continuously turning off the first semiconductor switch means when the state determined by the determination means as the overcurrent continues for a load side accident determination required period or longer;
The power supply side semiconductor circuit breaker is:
Second semiconductor switch means for conducting / interrupting the first power supply line by turning on / off the switch;
Second overcurrent determination means for determining whether or not a direct current flowing through the second semiconductor switch means is an overcurrent;
When the second overcurrent determining means determines that the overcurrent is present, the power supply side retry operation is repeated to turn on and off the second semiconductor switch means at the predetermined timing, and the second overcurrent is determined. When the state determined by the current determination means as the overcurrent continues for a power-side accident determination required period longer than any of the load-side accident determination required periods in all the load-side semiconductor circuit breakers, the second A DC power feeding system comprising: second retry control means for continuously turning off the semiconductor switch means. One power supply side semiconductor circuit breaker for supplying / disconnecting a first power supply line that supplies DC power from the power supply device to one load device and is connected to the power supply device and through which a direct current from the power supply device flows. And a single load-side semiconductor circuit breaker for conducting / cut-off of a second power supply line connected to the load device and through which a direct current from the power supply-side semiconductor circuit breaker flows. ,
The load-side semiconductor circuit breaker is
First semiconductor switch means for conducting / interrupting the second power supply line by turning on / off the switch;
First overcurrent determination means for determining whether or not a direct current flowing through the first semiconductor switch means is an overcurrent;
When the first overcurrent determination unit determines that the overcurrent is present, a load-side retry operation that repeats on / off of the first semiconductor switch unit at a predetermined timing is performed, and the first overcurrent is performed. First retry control means for continuously turning off the first semiconductor switch means when the state determined by the determination means as the overcurrent continues for a load side accident determination required period or longer;
The power supply side semiconductor circuit breaker is:
Second semiconductor switch means for conducting / interrupting the first power supply line by turning on / off the switch;
Second overcurrent determination means for determining whether or not a direct current flowing through the second semiconductor switch means is the overcurrent;
When the second overcurrent determining means determines that the overcurrent is present, the power supply side retry operation is repeated to turn on and off the second semiconductor switch means at the predetermined timing, and the second overcurrent is determined. The second semiconductor switch means is continued when the state judged as the overcurrent by the current judgment means continues for a power-side accident determination required period longer than the load-side accident determination required period of the load-side semiconductor circuit breaker. DC power supply system characterized by comprising second retry control means for automatically turning off. In the DC power supply system according to claim 1 or 2,
A setting device,
The setting device includes a setting unit that sets the load-side accident determination required period and the power-side accident determination required period. The DC power supply system according to any one of claims 1 to 3,
The load-side accident determination required period is a period until a predetermined load-side accident determination time elapses or a period in which the load-side retry operation is performed for the load-side semiconductor circuit breaker.
The power supply side accident determination required period is a period until a predetermined power supply side accident determination time that is longer than the load side accident determination time elapses, or the power supply side retry operation is greater than the load side retry count. A DC power supply system characterized in that it is a period in which the number of retries on the power supply side of a semiconductor breaker is performed.

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