TWI853314B - Digital logic circuit for controlling output with binary sum parameter, and power distribution system - Google Patents

Abstract

The present invention discloses a digital logic circuit for controlling output with binary sum parameter, and a power distribution system. The digital logic circuit is applied to a first intelligent electronic device corresponding to a main feeder of a power distribution system. The first intelligent electronic device is electrically connected to a plurality of second intelligent electronic devices corresponding to a plurality of power distribution feeders respectively connected to the main feeder. The digital logic circuit includes a plurality of AND gates, and the AND gates are respectively arranged corresponding to the second intelligent electronic devices. Each AND gate includes three input terminals and one output terminal. The input terminals are respectively received a relay using parameter, a relay action parameter and a binary action parameter, and the output terminal is connected to the corresponding second intelligent electronic device, so as to control whether the corresponding distribution feeder stops power supply; wherein the binary action parameter is obtained from the binary sum parameter.

Description

Digital logic circuit and power distribution system with binary sum parameter output control

The present invention relates to a digital logic circuit, and in particular to a digital logic circuit and a power distribution system that controls output using a binary sum parameter.

Electricity supply is of great importance to people's livelihood, industry and economic development. In recent years, due to the impact of nuclear energy issues, environmental protection issues and the retirement of old units, while electricity demand continues to grow, electricity supply has become tighter than in previous years. Government departments and power companies have made every effort to implement relevant measures on the supply and demand sides to ensure a stable supply of electricity.

However, even if the government and power companies implement relevant measures on the supply and demand sides to ensure a stable supply of electricity, it is still impossible to completely avoid power outages or power cuts when accidents occur. Especially in the summer when electricity consumption is high and power supply is tight, a small accident may cause a power outage, or even cause the distribution system to collapse due to insufficient power supply.

Therefore, when the system is under-powered, how to avoid power distribution system power collapse has always been one of the most important issues for power companies.

In view of the above-mentioned topic, the purpose of the present invention is to provide a digital logic circuit and power distribution system with binary sum parameter control output. The present invention uses a simple digital logic circuit to selectively and automatically trip the power distribution feeder in response to insufficient power supply in the system, avoiding frequent logic planning and circuit modification, and instead adopting simple parameter setting changes to achieve the above-mentioned effect, thereby avoiding power supply collapse in the distribution system.

To achieve the above-mentioned purpose, according to the present invention, a digital logic circuit for controlling output with a binary sum parameter is applied to a first intelligent electronic device corresponding to a main feed line of a power distribution system. The first intelligent electronic device is electrically connected to a plurality of second intelligent electronic devices respectively corresponding to a plurality of distribution feed lines connected to the main feed line. The digital logic circuit includes a plurality of AND gates. The gates are respectively arranged corresponding to the second intelligent electronic devices. Each gate includes three input terminals and one output terminal. The input terminals receive a power bar usage parameter, a power bar action parameter and a binary action parameter respectively. The output terminal is connected to the corresponding second intelligent electronic device to control whether the corresponding power distribution feeder stops supplying power. The binary action parameter is obtained from the binary sum parameter.

To achieve the above-mentioned object, a power distribution system according to the present invention includes a main feed line, a plurality of distribution feed lines, a first intelligent electronic device and a plurality of second intelligent electronic devices. The distribution feed lines are connected to the main feed line. The first intelligent electronic device is arranged corresponding to the main feed line and has a digital logic circuit that controls the output with a binary sum parameter. The second intelligent electronic devices are electrically connected to the first intelligent electronic devices, and each second intelligent electronic device is respectively set corresponding to each power distribution feeder; wherein, the digital logic circuit includes a plurality of AND gates, each AND gate is respectively set corresponding to each second intelligent electronic device, each AND gate includes three input terminals and one output terminal, the input terminals respectively receive a power bar usage parameter, a power bar action parameter and a binary action parameter, and the output terminal is connected to the corresponding second intelligent electronic device to control whether the corresponding power distribution feeder stops supplying power; wherein, the binary action parameter is obtained from the binary sum parameter.

In one embodiment, when the first smart electronic device includes a low-frequency power drive and the low-frequency power drive is used, the power drive use parameter is 1, otherwise it is 0.

In one embodiment, when the low-frequency electric motor detects that the power supply frequency of the main feed line is lower than a predetermined frequency and lasts for a predetermined time, the electric motor action parameter is 1, otherwise it is 0.

In one embodiment, the AND gates correspond to a characteristic parameter respectively, and the binary sum parameter is binary deconstructed to obtain an action parameter; wherein, when the action parameter is the same as the characteristic parameter corresponding to one of the AND gates, the binary action parameter input to the one of the AND gates is 1.

In one embodiment, the power distribution system further includes a plurality of power distribution circuit breakers, which are arranged corresponding to the power distribution feeders, each power distribution circuit breaker is electrically connected to a corresponding second intelligent electronic device, and each second intelligent electronic device controls the corresponding power distribution circuit breaker to disconnect the power supply of the corresponding power distribution feeder.

In one embodiment, the voltage of the power distribution system is 11.95 or 23.9 kilovolts (kV).

As mentioned above, in the digital logic circuit and distribution system of the present invention that uses binary sum parameter to control output, the intelligent electronic device (IED) corresponding to the main feed line is used for logic planning. The setting of the electric stud is matched with the binary sum parameter to correspond to each distribution feed line to selectively and actively determine the tripping feed line of low-frequency load shedding, thereby responding to the system power shortage and actively protecting the distribution system from power supply collapse.

1: Power distribution system

11: The first smart electronic device

21~2n: Second smart electronic device

A1~An: AND gate (first AND gate~nth AND gate)

BUS: Bus

CB1~CBn: distribution circuit breaker

CT, CT1~CTn: Current transformer

CS1~CSn: control signal

F0: Main feed line

F1~Fn: power distribution feeder

I1, I2, I3: input terminals

Ia: Electric post usage parameters

Ib: Electric stop action parameters

Ic: Binary action parameter

MCB: Main Circuit Breaker

O: Output port

Figure 1 is a single-line schematic diagram of a power distribution system according to an embodiment of the present invention.

FIG2 is a schematic diagram showing the connection between a first smart electronic device and multiple second smart electronic devices in the power distribution system of FIG1.

FIG3 is a schematic diagram of a digital logic circuit for preventing power supply collapse in the first smart electronic device of FIG1.

The following will refer to the relevant figures to explain the digital logic circuit and power distribution system that uses binary sum parameters to control the output according to the embodiment of the present invention, in which the same components will be explained with the same reference symbols.

Some of the terms, symbols, signals or codes that appear in this article or diagram should be understood by technicians familiar with the field of electrical technology.

In order to cope with insufficient power supply and avoid power supply collapse of the distribution system, the distribution system of the present invention can use the intelligent electronic device (IED) corresponding to the main feeder for logical planning, and the setting of the electric post and the binary sum parameter correspond to each distribution feeder to selectively and actively determine the tripping feeder for low-frequency unloading. Among them, the tripping signal can be transmitted to the relevant distribution feeder via the Generic Object Oriented Substation Event (GOOSE) function of the IEC 61850 communication protocol, thereby protecting the distribution system from power supply collapse. The present invention can be applied to distribution levels, such as 11.95 kilovolts (kV) or 23.9kV distribution systems.

FIG. 1 is a single-line schematic diagram of a power distribution system 1 of an embodiment of the present invention; FIG. 2 is a schematic diagram of the connection between a first smart electronic device 11 and a plurality of second smart electronic devices 21 to 2n in the power distribution system 1 of FIG. 1; and FIG. 3 is a schematic diagram of a digital logic circuit in the first smart electronic device 11 of FIG. 1 for preventing power supply collapse.

Please refer to FIG. 1 . The voltage of the power distribution system 1 of the present embodiment may be, for example but not limited to, 11.95 kV or 23.9 kV. The power distribution system 1 may include a main feeder F0, a plurality of distribution feeders F1~Fn, a first intelligent electronic device 11, and a plurality of second intelligent electronic devices 21~2n. In addition, the power distribution system 1 of the present embodiment may also include a main circuit breaker MCB, a plurality of distribution circuit breakers CB1~CBn, and a plurality of current transformers CT, CT1~CTn.

The distribution feeders F1~Fn are connected to the main feeder F0. Here, the distribution feeders F1~Fn are connected to the main feeder F0 via a bus BUS. In the embodiment of the 11.95kV system, the upper limit of the number of distribution feeders is 10 (the maximum value of n is 10); in the embodiment of the 23.9kV system, the upper limit of the number of distribution feeders is 8 (the maximum value of n is 8). The voltage and number of distribution feeders F1~Fn depend on the actual usage.

The first intelligent electronic device 11 is set corresponding to the main feed line F0. The main circuit breaker MCB is set on the main feed line F0 and is electrically connected to the first intelligent electronic device 11. The main circuit breaker MCB is used to control whether the main feed line F0 supplies power downstream. When the main circuit breaker MCB is disconnected, the power supply to the distribution feed lines F1~Fn is stopped. The current transformer CT is used to sense the current of the main feeder F0, thereby outputting a corresponding control signal and transmitting it to the first intelligent electronic device 11, and the first intelligent electronic device 11 may include a protection stop. When the protection stop reaches a preset current, current, frequency or time setting condition, the first intelligent electronic device 11 may output a corresponding trip signal and transmit it to the main circuit breaker MCB, thereby disconnecting the power supply of the main feeder F0.

As shown in FIG. 1 and FIG. 2 , the second smart electronic devices 21 to 2n are electrically connected to the first smart electronic device 11, and each second smart electronic device 21 to 2n is respectively set corresponding to each power distribution feeder F1 to Fn (one-to-one correspondence). Here, the first smart electronic device 11 and the second smart electronic devices 21 to 2n can communicate with each other through the GOOSE function of the IEC 61850 communication protocol to transmit signals. In addition, each distribution circuit breaker CB1~CBn is set correspondingly to each distribution feeder F1~Fn (one-to-one correspondence), each distribution circuit breaker CB1~CBn is electrically connected to the corresponding second intelligent electronic device 21~2n, and each distribution circuit breaker CB1~CBn is used to control whether the corresponding distribution feeder F1~Fn supplies power. Here, when the second intelligent electronic device 21~2n notifies the corresponding distribution circuit breaker CB1~CBn to cut off (disconnect), the corresponding distribution feeder F1~Fn will be disconnected and stop supplying power. In addition, each current transformer CT1~CTn is used to sense the current of the corresponding distribution feeder F1~Fn, thereby outputting the corresponding sensing signal and transmitting it to the corresponding second intelligent electronic device 21~2n, and the second intelligent electronic device 21~2n can respectively include a protection busbar. When the protection busbar reaches the preset voltage, current, frequency or time conditions, the second intelligent electronic device 21~2n can disconnect the corresponding distribution circuit breaker CB1~CBn to stop the power supply of the corresponding distribution feeder F1~Fn.

In response to insufficient power supply, the first intelligent electronic device 11 of this embodiment also has a digital logic circuit that controls the output with a binary sum parameter, thereby controlling the corresponding distribution circuit breakers CB1~CBn to trip through the second intelligent electronic devices 21~2n and stop supplying power to the corresponding distribution feeders F1~Fn, so as to protect the distribution system 1 from power supply collapse.

Please refer to FIG. 3 , the aforementioned digital logic circuit may include a plurality of AND gates A1 to An, and the AND gates A1 to An are respectively arranged corresponding to the second intelligent electronic devices 21 to 2n (one-to-one correspondence). Each AND gate A1 to An includes three input terminals I1, I2, and I3 and an output terminal O, and the input terminals I1, I2, and I3 receive a power-bar usage parameter Ia, a power-bar action parameter Ib, and a binary action parameter Ic, respectively, and the output terminal O of each AND gate A1 to An is connected to the corresponding second intelligent electronic device 21 to 2n to control whether the corresponding power distribution feeder F1 to Fn is powered off. Here, the motor use parameter Ia and the motor action parameter Ib are derived from the use and setting of the motor of the first intelligent electronic device 11, and the binary action parameter Ic is determined according to the binary sum parameter pre-planned or set by the user; in addition, the control signals CS1~CSn outputted from the output terminals O of the AND gates A1~An can be respectively transmitted to the corresponding second intelligent electronic devices 21~2n, and the corresponding distribution circuit breakers CB1~CBn are controlled by the second intelligent electronic devices 21~2n to trip, thereby stopping the power supply of the corresponding electric feeder lines F1~Fn.

In other words, when the input and gate A1's motor use parameter Ia, motor action parameter Ib and binary action parameter Ic are all 1, the control signal CS1 output from the output terminal O of the gate A1 will be 1. The control signal CS1 can control the corresponding distribution circuit breaker CB1 to trip through the second intelligent electronic device 21, thereby stopping the power supply of the corresponding distribution feeder F1; when When the input and gate A2's motor use parameter Ia, motor action parameter Ib and binary action parameter Ic are all 1, the control signal CS2 output from the output terminal O of the gate A2 will be 1. The control signal CS2 can control the corresponding distribution circuit breaker CB2 to trip through the second intelligent electronic device 22, thereby stopping the power supply of the corresponding distribution feeder F2, and so on.

The following explains the meanings of the motor usage parameter Ia, motor action parameter Ib and binary action parameter Ic input to the input terminals I1, I2 and I3.

The power drive use parameter Ia and the power drive action parameter Ib: In this embodiment, when the first intelligent electronic device 11 includes a low-frequency power drive (81L) and the low-frequency power drive (81L) is used, the power drive use parameter Ia is 1, otherwise the power drive use parameter Ia is 0. In other words, the first intelligent electronic device 11 of this embodiment must include a low-frequency power drive (81L) to make the output terminal O of the AND gate A1~An have a chance to be 1. Here, assuming that the first intelligent electronic device 11 uses the function of the low-frequency electric drive (81L), the electric drive use parameter Ia input to all input terminals I1 of the gates A1~An is 1; and, when the low-frequency electric drive (81L) detects that the frequency of the main feed line F0 is lower than a predetermined frequency, the electric drive action parameter Ib is 1, otherwise the electric drive action parameter Ib is 0. This embodiment takes the low-frequency electric drive (81L) as an example, but is not limited to the low-frequency electric drive. In different embodiments, it can also be an electric drive of other types or functions.

Specifically, in this embodiment, when the first intelligent electronic device 11 uses a low-frequency motor (81L), the motor use parameter Ia input to all input terminals I1 of the gates A1 to An is 1. When the low-frequency motor (81L) detects that the frequency of the main feed line F0 is lower than the predetermined frequency, the motor action parameter Ib will change from 0 to is 1. At this time, the electric drive action parameter Ib input to the input terminal I2 of all gates A1~An is 1, which means that the power supply of the power supply system 1 may have problems (such as insufficient power supply), and the automatic tripping feeder function needs to be activated to stop supplying power to one or some distribution feeders. As for which one or some feeders to trip is determined by the binary sum parameter. In some application cases, the predetermined frequency is, for example but not limited to, 59.5Hz, 59Hz or 58.8Hz, or other frequencies, depending on the actual use or setting.

In addition to the above situations, in different application cases, the low-frequency electric drive (81L) can detect that the power supply frequency of the main feed line F0 is lower than the predetermined frequency and lasts for a predetermined time, and then the electric drive action parameter Ib changes from 0 to 1 (otherwise it remains 0). Here, the predetermined time is, for example but not limited to, 30 seconds, 50 seconds or 1 minute, or other time, depending on the actual use or setting situation. In some embodiments, the low-frequency electric drive (81L) can also be set in two stages (i.e., 87L1 and 87L2), and the function of automatically tripping the feed line can be achieved as long as one of the stages is set. Here, the digital logic planning of the two-stage setting of 87L1 and 87L2 can be the same.

In addition, in the binary action parameter Ic: the state (0 or 1) of the binary action parameter Ic is determined by the binary sum parameter. In other words, the user can proactively plan in advance through the binary sum parameter which distribution feeders are more important and cannot be temporarily shut down; and which feeders are less important and can be temporarily shut down. If the system power supply is insufficient, there is no need to change the original digital logic circuit of the first intelligent electronic device 11, and the value of the binary sum parameter can be selectively set to obtain the corresponding state of the binary action parameter Ic to achieve the tripping of the less important distribution feeders. Here, the binary sum parameter can be planned in advance according to the actual situation and pre-stored in the first smart electronic device 11, or temporarily input into the first smart electronic device 11 through the input interface, and the present invention is not limited thereto.

The following uses the maximum upper limit of the 11.95kV distribution system: n=10, that is, the distribution system 1 includes 10 distribution feeders F1~F10 as an example to illustrate how to obtain the state of the binary action parameter Ic from the binary sum parameter. Here, each AND gate A1~A10 and/or each distribution feeder F1~F10 can be defined separately to correspond to a characteristic parameter, as shown in Table 1 below, the characteristic parameter corresponding to AND gate A1 and distribution feeder F1 is "1", the characteristic parameter corresponding to AND gate A2 and distribution feeder F2 is "2", and so on; and the binary sum parameter can obtain at least one action parameter after binary deconstruction; when the action parameter is the same as the characteristic parameter corresponding to one of the AND gates, the binary action parameter Ic input into one of the AND gates is 1 (otherwise 0). In other words, the first AND gate A1 to the tenth AND gate A10 correspond to characteristic parameters: "1" to "10", respectively. When the action parameter obtained after binary decomposition of the binary sum parameter contains the same characteristic parameter corresponding to one of the AND gates, the binary action parameter Ic input to one of the AND gates is 1, and the rest is 0. If there are 2 action parameters obtained after binary decomposition of the binary sum parameter, and these 2 action parameters are the same as the characteristic parameters corresponding to the 2 AND gates, the binary action parameters Ic input to these 2 AND gates are both 1, and the rest is 0.

For example, in an application example, please refer to Table 1 again. Assume that the binary sum parameter is equal to 3. Because 3=1+2=2 ⁰ +2 ¹ , the action parameter corresponding to "2 ⁰ " is "1", and the action parameter corresponding to "2 ¹ " is 2. Therefore, the action parameters of the binary sum parameter 3 after binary deconstruction include: "1" and "2", which are the same as the characteristic parameters "1" and "2" corresponding to the distribution feeder F1 and F2 respectively. Therefore, the binary action parameters Ic of the first and second gates A1 and A2 are all 1 (the binary action parameters Ic of the third and tenth gates A3 to A10 are all 0). Therefore, the first and second gates A1 and A2 are The control signals CS1 and CS2 of the output terminal O can be 1 respectively, and the control signals CS1 and CS2 which are 1 respectively can control the distribution circuit breakers CB1 and CB2 of the distribution feeders F1 and F2 to trip through the corresponding second intelligent electronic devices 21 and 22, thereby stopping the power supply to the distribution feeders F1 and F2, thereby responding to insufficient power supply of the system and selectively and actively tripping the distribution feeders F1 and F2 to protect the distribution system 1 from power supply collapse.

In another application example, assume that the binary sum parameter is equal to 13, because 13=1+4+8=2 ⁰ +2 ² +2 ³ , the action parameter corresponding to "2 ⁰ " is "1", the action parameter corresponding to "2 ² " is 3, and the action parameter corresponding to "2 ⁴ " is 4. Therefore, the deconstructed action parameters include: "1", "3" and "4", which are the same as the characteristic parameters "1", "3", and "4" corresponding to the distribution feeder F1, F3, and F4 respectively. Therefore, the binary action parameters Ic of the first gate A1, the third gate A3, and the fourth gate A4 are all 1 (the binary action parameters of the second gate A2, the fifth gate A5~the tenth gate A10 are all 0). Therefore, The control signals CS1, CS3, CS4 of the output terminals O of the first gate A1, the third gate A3, and the fourth gate A4 will be 1 respectively, and the control signals CS1, CS3, CS4 which are 1 respectively can control the distribution circuit breakers CB1, CB3, CB4 of the distribution feeders F1, F3, F4 to trip through the corresponding second intelligent electronic devices 21, 23, 24, and selectively stop supplying power to the distribution feeders F1, F3, F4; and so on.

In summary, in the digital logic circuit and distribution system of the present invention that uses binary sum parameter to control output, the intelligent electronic device (IED) corresponding to the main feeder is used for logic planning. The setting of the electric post is matched with the binary sum parameter corresponding to each distribution feeder to selectively and actively determine the tripping feeder of low-frequency load shedding, thereby responding to the system power shortage and actively protecting the distribution system from power supply collapse.

The above description is for illustrative purposes only and is not intended to be limiting. Any equivalent modification or change made to the invention without departing from the spirit and scope of the invention shall be included in the scope of the patent application attached hereto.

1: Power distribution system

11: The first smart electronic device

21~2n: Second smart electronic device

BUS: Bus

CB1~CBn: distribution circuit breaker

CT, CT1~CTn: Current transformer

CS1~CSn: control signal

F0: Main feed line

F1~Fn: power distribution feeder

MCB: Main Circuit Breaker

Claims (8)

A digital logic circuit for controlling output with a binary sum parameter is applied to a first intelligent electronic device corresponding to a main feed line of a power distribution system. The first intelligent electronic device is electrically connected to a plurality of second intelligent electronic devices respectively corresponding to a plurality of distribution feed lines connected to the main feed line. The digital logic circuit comprises: a plurality of AND gates respectively arranged corresponding to the second intelligent electronic devices, each of the AND gates comprising three input terminals and one output terminal. The input terminals receive a power-steering use parameter, a power-steering action parameter and a binary action parameter respectively, and the output terminal is connected to the corresponding second intelligent electronic device to control whether the corresponding power distribution feeder stops supplying power; wherein the binary action parameter is obtained from the binary sum parameter; wherein, when the first intelligent electronic device includes a low-frequency power-steering and the low-frequency power-steering is used, the power-steering use parameter is 1, otherwise it is 0. A digital logic circuit as described in claim 1, wherein when the low-frequency electric drive detects that the power supply frequency of the main feed line is lower than a predetermined frequency and lasts for a predetermined time, the electric drive action parameter is 1, otherwise it is 0. A digital logic circuit as described in claim 1, wherein the AND gates correspond to a characteristic parameter respectively, and the binary sum parameter is binary-deconstructed to obtain an action parameter; wherein, when the action parameter is the same as the characteristic parameter corresponding to one of the AND gates, the binary action parameter input to the one of the AND gates is 1. A power distribution system includes: a main feeder; a plurality of distribution feeders connected to the main feeder; a first intelligent electronic device, arranged corresponding to the main feeder and having a digital logic circuit for controlling output with a binary sum parameter; and a plurality of second intelligent electronic devices, each electrically connected to the first intelligent electronic device, and each of the second intelligent electronic devices is arranged corresponding to each of the distribution feeders; wherein the digital logic circuit includes a plurality of AND gates, each of which is respectively connected to each of the second intelligent electronic devices. Correspondingly, each AND gate includes three input terminals and one output terminal, the input terminals receive a power-bar usage parameter, a power-bar action parameter and a binary action parameter respectively, and the output terminal is connected to the corresponding second intelligent electronic device to control whether the corresponding power distribution feeder stops supplying power; wherein the binary action parameter is obtained from the binary sum parameter; wherein, when the first intelligent electronic device includes a low-frequency power bar and the low-frequency power bar is used, the power bar usage parameter is 1, otherwise it is 0. A power distribution system as described in claim 4, wherein when the low-frequency electric motor detects that the power supply frequency of the main feeder is lower than a predetermined frequency and lasts for a predetermined time, the electric motor action parameter is 1, otherwise it is 0. A power distribution system as described in claim 4, wherein the AND gates correspond to a characteristic parameter respectively, and the binary sum parameter is binary-deconstructed to obtain an action parameter; wherein, when the action parameter is the same as the characteristic parameter corresponding to one of the AND gates, the binary action parameter input to the one of the AND gates is 1. The power distribution system as described in claim 4 further includes: a plurality of power distribution circuit breakers, which are arranged corresponding to the power distribution feeders, each of which is electrically connected to the corresponding second intelligent electronic device, and each of which controls the corresponding power distribution circuit breaker to disconnect the power supply of the corresponding power distribution feeder. The distribution system as described in claim 4 has a voltage of 11.95 or 23.9 kilovolts (kV).

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