Plant monitoring system and plant monitoring device

Abstract

To reduce a workload on an operator etc. by providing a function for automatic remote monitoring of an abnormality of an electrical circuit, and improve reliability of a power system by early detection of a failure.SOLUTION: A plant monitoring system for monitoring a plant facility including at least one of load circuits, main circuits and circuit breakers installed in a plurality of plants, comprises a monitoring device having a signal receiving unit and a determination unit. Electric quantity measuring instruments are installed in the load circuit and the main circuit. The circuit breaker is equipped with the electric quantity measuring instrument or an operating signal detector. The signal receiving unit receives at least one of an electrical measurement signal including current measured by the electrical quantity measuring instrument and an operation signal of the circuit breaker detected by the operating signal detector. The determination unit compares at least one of the electrical measurement signals and the operating signals between two or more of the plurality of plants, and determines that there is an abnormality in the load circuit, the main circuit or the circuit breaker if a difference in values of the signals is greater than or equal to a predetermined value.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a plant monitoring system and a plant monitoring device. [Background technology]

[0002] Typically, the operating status of electrical equipment within a plant, such as circuits and loads, is monitored by managers and operators (hereinafter referred to as "operators, etc.") using instruments installed on monitoring panels and on-site. Any abnormalities are detected by protective relays installed on each circuit, and an alarm is issued. Operators, etc. become aware of the occurrence of an abnormality through the alarm. In such cases, operators, etc., only become aware of the abnormality after checking the alarm, and so they tend to be slow to take action, such as replacing or repairing the equipment. This situation leads to a decrease in the operating rate of the power plant.

[0003] In order to take proactive measures, it is necessary to constantly monitor electrical measurement signals through regular testing and pay attention to changes in the state of electrical circuits. Currently, it is difficult to detect abnormalities early from measurement data, and test personnel are required to make judgments based on judgment values ​​and past experience.

[0004] On the other hand, it is expected that future power systems will be decentralized, and if many small-scale power plants are installed, there will be an issue that implementing the above-mentioned monitoring will require a large number of human resources. In response to this issue, a system for remote centralized monitoring when multiple power plants are installed has already been proposed.

[0005] Patent document 1 discloses that measuring instruments such as sensors are attached to hydroelectric power plant equipment, including water level gauges, inlet valves, water turbines, servo motors, generators, circuit breakers, transformers, power transmission equipment, etc., and that the measuring instruments measure physical quantities such as pressure and temperature of the attached equipment, and electrical quantities such as voltage, current, and frequency, that each measuring instrument outputs the measurement value to a monitoring and control system, that the monitoring and control device of the monitoring and control system is connected to a monitoring and control terminal device via a network, that the monitoring and control terminal device is located in a remote location away from the hydroelectric power plant, and that while multiple monitoring and control terminal devices can monitor multiple hydroelectric power plants simultaneously, control authority over the hydroelectric power plant equipment is given to one monitoring and control terminal device, thereby enabling those involved in the hydroelectric power plant to control the operation of the hydroelectric power plant equipment conveniently and without confusion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2021-103447 A Summary of the Invention [Problem to be solved by the invention]

[0007] In Patent Document 1, hydroelectric power plants are subject to monitoring, but this is not the only subject, and power generation facilities such as wind power generation and solar power generation facilities are becoming relatively small and are being deployed in a dispersed manner.

[0008] Power plants are equipped with protective relays as electrical equipment. Protective relays are capable of detecting abnormal events such as overcurrent, ground fault, short circuit, low voltage, and overvoltage. Specifically, protective relays detect extreme changes in electrical behavior caused by abnormalities in a circuit, such as an increase in zero-phase current or zero-phase voltage in the case of a ground fault, as an abnormality.

[0009] When such extreme changes in electrical behavior occur, it is often the case that some kind of fault has already occurred on the circuit. In this case, the plant must be shut down to verify the fault and replace the equipment. As a result, the plant may be shut down for a long period of time, resulting in a decrease in the plant's operating rate. In order to avoid such events, it is necessary to regularly grasp the status of each load, recognize abnormalities in the load early, secure a period of time to prepare for abnormalities, make sufficient preparations in advance, and have a system in place to quickly return to normal operating conditions if an abnormality occurs.

[0010] In recent years, the study of distributed power sources has accelerated, and it is expected that many small-scale power plants will be installed in the future power grid. In that case, human resources to monitor the above-mentioned abnormalities will be required for each plant, and there is a possibility that the shortage of human resources will become significant. In order to avoid this, a system that automatically monitors abnormalities is desirable.

[0011] An object of the present disclosure is to provide a function for automatic remote monitoring of abnormalities in electrical circuits, thereby reducing the burden on operators and improving the reliability of power systems by detecting faults early. [Means for solving the problem]

[0012] The plant monitoring system disclosed herein is a system that monitors plant equipment including at least one of load circuits, main circuits, and circuit breakers installed in multiple plants, and is equipped with a monitoring device having a signal receiving unit and a judgment unit, wherein an electrical quantity measuring instrument is installed in the load circuit and main circuit, and an electrical quantity measuring instrument or an operation signal detector is installed in the circuit breaker, and the signal receiving unit receives at least one of an electrical measurement signal including a current measured by the electrical quantity measuring instrument and an operation signal of the circuit breaker detected by the operation signal detector, and the judgment unit compares at least one of the electrical measurement signal and the operation signal between two or more plants among the multiple plants, and if the difference in the values ​​of the signals is equal to or greater than a predetermined value, judges that there is an abnormality in the load circuit, the main circuit, or the circuit breaker. Effect of the Invention

[0013] According to the present disclosure, a function for automatic remote monitoring of abnormalities in electrical circuits is provided, which reduces the burden on operators and others, and improves the reliability of the power supply system by detecting failures early. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic configuration diagram showing a connection state of a plant according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a load state and a plant mode of the plant. [Diagram 3] FIG. 1 is a schematic diagram showing an example of a configuration for comparing electrical measurement signals using a virtual plant created by simulation in a plant monitoring device. [Figure 4] FIG. 13 is a schematic diagram showing an example of a configuration for comparing electrical measurement signals when plants connected to different systems are in the same plant mode. [Diagram 5] 1 is a schematic configuration diagram showing a plant monitoring device according to an embodiment; [Figure 6] FIG. 2 is a flow diagram showing an abnormality determination method by the plant monitoring device of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A plant monitoring system according to the present disclosure includes a plurality of plants and a plant monitoring device. The plant monitoring system may further include one or more systems.

[0016] The plant monitoring system estimates the plant mode from electrical quantities measured by electrical meters installed on load circuits (hereinafter also referred to as "loads") and main circuits (hereinafter also referred to as "main electrical circuits") within the plant, and signals related to the open / close status of electrical circuits, and compares the current values ​​of each circuit of the plant being evaluated with the current values ​​of each circuit of other plants in the same plant mode. If a difference between them that exceeds a certain threshold is found, it is determined to be an abnormality.

[0017] In this specification, a plant refers to equipment such as a power plant. The plant includes at least one of loads, main circuits, and circuit breakers. The plant equipment is configured to be monitored by a plant monitoring device. In addition, a similar plant mode includes not only the same plant mode, but also plant modes that are nearly the same, i.e., have similar states.

[0018] A plant monitoring device (also simply referred to as a "monitoring device") has a signal receiving unit (input unit) and a judgment unit (detection / judgment unit). Of the plant equipment, electric quantity measuring instruments are installed on the loads and main electric circuits. Also, an electric quantity measuring instrument or an operation signal detector is installed on the circuit breaker. The signal receiving unit of the monitoring device receives at least one of an electric measurement signal including a current value measured by the electric quantity measuring instrument, and an operation signal of the circuit breaker detected by the operation signal detector.

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0020] FIG. 1 is a schematic configuration diagram showing a connection state of a plant according to an embodiment.

[0021] In this figure, a first plant 104, a second plant 105, and a third plant 106 are connected to a first system 101. A fourth plant 107 is connected to a second system 102. The first system 101 and the second system 102 are connected by a connection bus 103. In this specification, the term "main electric circuit" may include not only main wiring within a plant, but also connecting wiring and connection buses between the systems and plants.

[0022] A first plant 104, a second plant 105, a third plant 106, and a fourth plant 107 are connected to a plant monitoring device 100. The plant monitoring device 100 acquires electrical measurement signals from each plant, performs predetermined calculation processing, determines whether or not there is an abnormality, and notifies an operator, etc., as necessary.

[0023] Here, the first system 101 and the second system 102 are separate systems and are not identical in electrical quality. Therefore, even if the electrical equipment installed in each of the first plant 104, the second plant 105, the third plant 106, and the fourth plant 107 has the same specifications, the electrical measurement signals of the first plant 104, the second plant 105, and the third plant 106 and the electrical measurement signal in the fourth plant 107 have different system conditions, and therefore are signals with different characteristics.

[0024] FIG. 2 is a schematic diagram showing the load state and plant mode of the plant.

[0025] In the example shown in this figure, the loads installed in each plant are three pumps. When all three pumps in one plant are operating (when all are ON), this is considered to be the first mode. When all three pumps are stopped (when all are OFF), this is considered to be the second mode. The first mode and the second mode are examples of plant modes.

[0026] A plant monitoring device 100 (FIG. 1) acquires signals from electric quantity measuring instruments such as digital relays and ammeters provided on each load, and from circuit breaker on / off signals, detects operation or stop of the loads, and estimates the plant mode.

[0027] When the plant monitoring device 100 detects the load state of the first plant 104, it estimates that the plant is in the first mode since all the loads are operating. When the plant monitoring device 100 detects the load state of the second plant 105, it estimates that the plant is in the second mode since all the loads are stopped. When the plant monitoring device 100 detects the load state of the third plant 106, it estimates that the plant is in the first mode since all the loads are operating. In this case, the magnitude of the current values ​​of the first plant 104 and the third plant 106, which are both estimated to be in the first mode, are compared, and if the difference is equal to or greater than a certain value, it is determined that an abnormality has occurred.

[0028] In addition, in this figure, a case has been described in which the load is a pump, but other loads according to the present disclosure include a motor and the like.

[0029] In Fig. 1, the first plant 104, the second plant 105, and the third plant 106 connected to the first system 101 are different in electrical specifications, such as the voltage on the system side, from the fourth plant 107 connected to the second system. For this reason, it is difficult to simply compare electrical measurement signals in plants of different systems. In addition, when there is no comparison target, for example, when there is no other plant in the connected system like the fourth plant 107, or when there is no plant of the same plant mode even if the system is the same like the second plant 105 in Fig. 2, it is also difficult to compare electrical measurement signals.

[0030] In such a case, a virtual plant is created by simulation and compared with the actual plant to determine whether there is an abnormality.

[0031] FIG. 3 is a schematic diagram showing an example of a configuration for comparing electrical measurement signals using a virtual plant created by simulation in a plant monitoring device.

[0032] In this figure, in the plant monitoring device 100, an analysis (simulation) is performed simulating the same plant mode (here, the third mode) as the fourth plant 107 to be evaluated, and an abnormality is determined by comparing the measurement signal of the fourth plant 107 with the current value obtained by simulating the third mode of the fourth plant 107.

[0033] FIG. 4 is a schematic diagram showing an example of a configuration for comparing electrical measurement signals when plants connected to different systems are in the same plant mode.

[0034] In this figure, similarly to Fig. 1, the first system 101 having the first plant 104, the second plant 105, and the third plant 106 and the second system 102 having the fourth plant 107 have different power supply specifications and conditions, and also different voltage values. Assuming this as a prerequisite, even if the first plant 104, the third plant 106, and the fourth plant 107 are operating in the same plant mode (first mode), a change in voltage will cause a change in current due to load characteristics (constant power characteristics and constant impedance characteristics). For this reason, a simple comparison of current values ​​will result in a state in which a difference always occurs, making it difficult to determine an abnormality.

[0035] Here, the voltage values ​​of the first system 101 and the second system 102 are input to the plant monitoring device 100 (FIG. 1). Then, in the plant monitoring device 100, the system voltage value of the plant to be referred to of the two plants is replaced with the voltage value of a reference plant 407 to be compared, and the load current value is estimated by simulation, and by using the estimated current value, it becomes possible to compare the plant 407 to the reference plant even if the plant is a different system from the reference plant. In this case, the system may be an off-site power supply system or an on-site power supply system within the plant.

[0036] As a simple example, consider a case where the load is a resistive load with constant impedance characteristics under the conditions that the bus voltage of the first plant 104 is 6.90 kV and the bus voltage of the fourth plant 107 is 6.85 kV, which are different from each other. Although the bus voltage of the fourth plant 107 is actually 6.85 kV, the current value when it is set to 6.90 kV is estimated by simulation.

[0037] In the case of a constant impedance characteristic, the load currents increase at a ratio of 6.90 kV / 6.85 kV. In this way, by making the voltage conditions between the first plant 104 and the fourth plant 107 uniform, it becomes possible to compare the current values.

[0038] In this example, we have focused on voltage only to simplify the explanation, but the same applies when conditions such as frequency change. Compared to Fig. 3, this has the advantage that it is not necessary to build an entire system model, and only the conversion of current values ​​is required.

[0039] When there are many plant modes to be distinguished, it is possible to distinguish various operation modes based on the load energization sequence, the magnitude of the load current, etc. For example, in a power plant, a startup sequence for supplying emergency power as an emergency operation is determined for each event, so it is also possible to assume the plant mode based on the load energization sequence.

[0040] In this example, we have mainly explained the comparison of current values, but by processing the current values ​​and comparing other measurement signals, more detailed comparisons and analyses are possible. For example, by decomposing the measured current values ​​into symmetrical components using the symmetric coordinate method, it becomes possible to monitor earth faults and unbalance rates, which cannot be determined by the magnitude of the current alone. By combining measurements such as voltage values ​​and frequency, it becomes possible to monitor circuit losses, motor torque, slip, and so on.

[0041] The configuration and processing flow of the plant monitoring device according to the embodiment will be described below.

[0042] FIG. 5 is a schematic configuration diagram showing a plant monitoring device according to an embodiment.

[0043] In this figure, the plant monitoring device 100 includes an input unit 151 , a detection and determination unit 152 , an analysis unit 153 , an output unit 154 , and a storage unit 160 .

[0044] The input unit 151 receives electrical measurement signals from each plant. The detection and determination unit 152 performs a predetermined calculation process on the received electrical measurement signals to determine the presence or absence of an abnormality. The analysis unit 153 performs the above simulation. The output unit 154 transmits notifications regarding the results of the determination and the simulation to operators, etc. The memory unit 160 transmits necessary data to the detection and determination unit 152 and the analysis unit 153, and receives data that needs to be stored from the detection and determination unit 152 and the analysis unit 153.

[0045] FIG. 6 is a flow diagram showing an anomaly determination method by the plant monitoring device of the embodiment.

[0046] As shown in the figure, in the plant monitoring device, the detection and judgment unit 152 detects the load state of the plant from the data received by the input unit 151 (step S610). Then, the detection and judgment unit 152 estimates the mode of the plant from the load state of the plant (step S620). Next, the detection and judgment unit 152 compares plants of the same mode (step S630). Then, the detection and judgment unit 152 judges whether there is an abnormality in the plant (step S640). If there is an abnormality, the output unit 154 notifies the operator or the like of the abnormality (step S650). If there is no abnormality, the process returns to step S610.

[0047] Preferred embodiments of the plant monitoring system and the plant monitoring device according to the present disclosure will be described below.

[0048] The determination unit estimates the plant mode from at least one of the electrical measurement signal and the operation signal, and compares two or more plants in the same plant mode among the multiple plants.

[0049] The determination unit estimates a plant mode of the actual plant from at least one of the measured electrical measurement signals and the detected operation signals. The analysis unit creates a virtual plant by simulating the plant mode. The determination unit then compares at least one of the electrical measurement signals and the operation signals between the actual plant and the virtual plant, and determines that an abnormality exists in the load circuit, the main circuit, or the breaker if the difference in the signal value is equal to or greater than a predetermined value.

[0050] The determining unit estimates the plant mode based on at least one signal of the energization sequence of the load circuits and the magnitude of the current in the load circuits.

[0051] The determination unit makes a comparison by making the voltage or frequency conditions uniform between two or more plants.

[0052] The load circuit has an electric motor, and the judgment unit compares the torque or slip of the electric motor between two or more plants based on the current and voltage values, and judges that the load circuit is normal if the difference in the torque or slip value is less than a predetermined value.

[0053] The power generation facilities that can be monitored by the plant monitoring system according to the present disclosure include hydroelectric power plants, wind power generation facilities, solar power generation facilities, geothermal power plants, nuclear power plants, and the like. [Explanation of symbols]

[0054] 100: plant monitoring device, 101: first system, 102: second system, 103: connecting bus, 104: first plant, 105: second plant, 106: third plant, 107: fourth plant, 151: input unit, 152: detection / judgment unit, 153: analysis unit, 154: output unit, 160: memory unit, 407: comparison plant.

Claims

1. A system for monitoring plant equipment including at least one of a load circuit, a main circuit, and a breaker installed in a plurality of plants, comprising: A monitoring device having a signal receiving unit and a determination unit, An electric quantity measuring instrument is installed in the load circuit and the main circuit, The circuit breaker is provided with an electric quantity measuring device or an operation signal detector, The signal receiving unit receives at least one of an electrical measurement signal including a current measured by the electrical quantity measuring device and an operation signal of the circuit breaker detected by the operation signal detector, the determination unit compares at least one of the electrical measurement signal and the operation signal between two or more plants among the plurality of plants, and determines that an abnormality exists in the load circuit, the main circuit, or the breaker when a difference in the value of the signal is equal to or greater than a predetermined value; The determination unit estimates a plant mode from at least one of the electrical measurement signal and the operation signal, and performs the comparison between two or more plants in the same plant mode among the multiple plants.

2. A system for monitoring plant equipment including at least one of a load circuit, a main circuit, and a breaker installed in a plant, comprising: A monitoring device having a signal receiving unit, a determining unit, and an analyzing unit, An electric quantity measuring instrument is installed in the load circuit and the main circuit, The circuit breaker is provided with an electric quantity measuring device or an operation signal detector, The signal receiving unit receives at least one of an electrical measurement signal including a current measured by the electrical quantity measuring device and an operation signal of the circuit breaker detected by the operation signal detector, The determination unit estimates a plant mode of an actual plant from at least one of the measured electrical measurement signal and the detected operation signal, the analysis unit creates a virtual plant by simulating the plant mode; The judgment unit compares at least one of the electrical measurement signal and the operation signal between the actual plant and the virtual plant, and if a difference in the value of the signal is equal to or greater than a predetermined value, judges that an abnormality exists in the load circuit, the main circuit, or the breaker.

3. 3. The plant monitoring system according to claim 2, wherein the determining unit estimates the plant mode based on at least one signal of a power supply sequence of the load circuits and a magnitude of a current in the load circuits.

4. The plant monitoring system according to claim 1 , wherein the determination unit makes the comparison by making voltage or frequency conditions uniform between the two or more plants.

5. The load circuit includes an electric motor.

5. The plant monitoring system according to claim 4, wherein the determination unit compares the torque or slip of the motor between the two or more plants from the current and voltage values, and determines that the load circuit is normal if a difference in the torque or slip value is less than a predetermined value.

6. An apparatus for monitoring plant equipment including at least one of a load circuit, a main circuit, and a breaker installed in a plurality of plants, comprising: A signal receiving unit; A determination unit, the signal receiving unit receives at least one of an electrical measurement signal including a current value measured by an electrical quantity measuring device installed in the load circuit and the main circuit, and an operation signal of the circuit breaker detected by an operation signal detector installed in the circuit breaker; the determination unit compares at least one of the electrical measurement signal and the operation signal between two or more plants among the plurality of plants, and determines that an abnormality exists in the load circuit, the main circuit, or the breaker when a difference in the value of the signal is equal to or greater than a predetermined value; The determination unit estimates a plant mode from at least one of the electrical measurement signal and the operation signal, and performs the comparison between two or more plants in the same plant mode among the multiple plants.

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