JP3080795B2 - Power system frequency simulation method and power system training simulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simulator for power system training during normal times and system accidents, and more particularly, to accurately and in real time simulate system accident phenomena when a multi-system standby computer is used as a training simulator. Training simulators that need to be done.

[0002]

2. Description of the Related Art FIG. 2 shows a system configuration example of a conventional simulator for power system training. FIG. 3 shows a flow of a conventional system simulation calculation process, which is a creation target of the present invention. Here, the system simulation calculation is, for example, binary (on and off) information of an electric power system required for performing training,
Refers to simulation of numerical information. In addition, the binary information indicates, for example, on / off operation of a relay, CB state change, and the like.
Numerical information refers to various information such as system frequency, power, reactive power, voltage, phase angle, and current. Here, the training means training for a driver who is in charge of operation and operation of the power system / equipment to quickly and accurately deal with an emergency situation actually occurring due to an accident or the like. Conventional systems are:
For example, it comprises a computer 1, a system board 2, a training instructor's desk 4, a trainee's table 3, and a system simulation computer 5.
Further, the computer is configured to include, for example, a display output processing unit, a man-machine processing unit, a demand / supply capacity calculation processing unit, a current system state base, and a system definition database.
The man-machine processing means stores information for system operation input from the training instructor's desk 4, system connection status information, data on training contents such as system accidents in a storage area built in the computer 1. Store. The demand / supply capacity calculation processing means performs calculation processing of total demand, power generation supply capacity, and the like based on a current system state database, a system definition database, and the like stored in a storage area in the computer. Determines whether to send output command data or the like.
The system simulation calculation processing means uses processing results and the like in the demand / supply power calculation processing means as input data and, for example, power flow (referred to as active power / reactive power flow), voltage, frequency, etc.
Calculate the data required for trainee training. The display output processing means edits the final processing result data into display data for the training instructor and the trainee,
Output to T etc. Further, in order to enable a faithful simulation (hereinafter, also referred to as “simulation”) of a system accident, the operation simulation of the system stabilizing device performed by the above-described system simulation calculation processing means and the “frequency relay / CB ( Ci
rbreak Breaker: state variable combination "(when the off state of the CB changes within a predetermined time based on the operation of the frequency relay detected first,
It is necessary to process an accident state change simulation by real-time processing, which is a process that is treated as an accident when the condition is satisfied.

[0003] Further, the system stabilizing device includes a power loss (hereinafter, also referred to as a "generator trip", in which the generator CB is turned off due to a generator accident and the generator is separated from the power system), system separation, and the like. In the event of an accident, it is assumed in advance, and as a necessary control measure, each feeder (referred to a distribution line that is drawn from the distribution substation and has no load connected to the first branch point) is connected to the frequency relay. The settling frequency ("settling" means to be set in advance) as the operating condition is set, for example, in units of 0.1 (Hz), and the settling time is set in units of 0.1 to 0.3 seconds. In this way, the system status is constantly monitored based on the settling frequency and the settling time, and if there is a frequency relay that satisfies the operating conditions, the frequency relay is operated and the load is rejected (between the load side and the demand). System with the side And a device to achieve a recovery of the system frequency by performing a designated) separating. Here, the frequency relay is a general term for a relay for maintaining and stabilizing a system frequency, and is a frequency reduction relay (UF).
R), a frequency increase relay (OFR), and the like. further,
The frequency lowering relay (UFR) is a relay that turns off the feeder CB when the frequency is abnormally low to cut off the load, and the frequency increasing relay (OFR) turns off the generator CB when the frequency is abnormally high and trips the generator. It is a relay. From the above description, in order to simulate the operation of the system stabilization device in the same manner as the actual system, the system frequency simulation process takes the frequency of 0.1 (Hz) unit into 0.1 by considering the transient phenomenon. Calculated in real time every 0.3 seconds,
Must simulate. For this reason, in the conventional simulator for power system training, as shown in FIGS. 2 and 3, the system simulation calculation process uses a high-speed computer with a high processing capability or an arithmetic processor to perform a complicated AC method. Power flow calculation, frequency calculation, frequency relay operation simulation, and the like have been performed in a short cycle such as a 0.1 to 0.3 second cycle.

[0004]

In recent years, even with a simulator for power system training using a multi-system standby system computer, it has become possible to faithfully simulate a system accident, and to recover from an accident in an environment full of realistic sensation equivalent to an actual system. It has been desired to provide a system capable of training such as training. However, instead of using a high-speed computer with a large processing capacity, an arithmetic processor, and the like, which have been employed in conventional simulators for electric power system training, only a multi-system standby computer is diverted to faithfully simulate a system accident or the like. If the processing is performed using the same processing logic as in the past, the processing will be over, and the simulation processing cannot be performed in real time. For this reason, there is a problem that a simulation similar to that of an actual system is not performed in the following simulation processing that is required at least for performing training such as accident recovery. First, regarding the operation simulation of the system stabilization device, as shown in FIG. 5, when the system frequency cannot be simulated in real time, the operation of the frequency relay based on the settling frequency and the settling time is performed. However, the operation is not the same as that of the actual system. FIG. 5 shows that FCB and FCB cannot be simulated in real time.
Indicates that extra operation simulation is performed.

[0005] Second, a simulation of accident detection by "combination of frequency relay and CB state change" is described. Here, in order to detect an accident, a combination of a frequency relay and a CB linked by its operation is referred to as a “frequency relay / CB state change combination”, and for each combination,
The related accident determination time is set in units of 1.0 second, and the accident detection processing is performed at the related accident determination time.
That is, “frequency relay / CB state change combination”
The combination of the frequency relay and CB defined in
If the operation is performed within the related accident determination time, the accident is detected as an accident, the occurrence of the accident is notified to an operator by an alarm or the like, and accident related information is created. Therefore, as shown in FIG. 6, when the simulation of the state change of the frequency relay and the CB cannot be performed in real time, the accident detection is missed (the feeder CB and the accident of the feeder CB are missed). ), The processing is not the same as online processing. An object of the present invention is to use a standby computer of a multi-system as a training simulator, and in any case of system simulation of a normal state and a system accident state, by enabling processing similar to real time, It is an object of the present invention to solve the above-mentioned problems and to provide a trainee with a training environment similar to a real system.

[0006]

To solve the above-mentioned problems, the following methods are conceivable. A method of simulating the frequency of an electric power system, in which an event including an accident, an operation of a frequency relay, and a lapse of time occurs, and when an imbalance in power supply and demand occurs, the inertia constant of the generator is set to M, When the internal phase difference angle is δ, the braking coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, the variation of the mechanical input of the generator is ΔPM, Assuming that the constant is TG, the frequency characteristic constant of the power supply is KG, and the amount of frequency change is Δf, the equation of motion of the generator is (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (d
δ / dt) + P = PM, and the transient characteristic of the governor provided in the generator is TG · (dΔPM / dt) + ΔPM + KG · Δf = 0, and the frequency after a predetermined time is calculated from the above equation (2). is there. A method for simulating the frequency of a power system having a standby system, comprising generating an event including an accident, an operation of a frequency relay, and time lapse, and generating an Is the inertia constant of M, the internal phase difference angle is δ, the damping coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, and the variation of the mechanical input of the generator is Assuming that ΔPM, the governor time constant is TG, the frequency characteristic constant of the power supply is KG, and the frequency change is Δf, the equation of motion of the generator is (M / ωn) · (d ² δ / dt ² ) + (D / ωn) ・ (d
δ / dt) + P = PM, and the transient characteristic of the governor provided in the generator is TG · (dΔPM / dt) + ΔPM + KG · Δf = 0. A method of calculating using a calculation means is also conceivable. Further, in the above method, a method of displaying the calculation result of the frequency on the display means is preferable. The means described below can be considered as means using the above method. In a power system training simulator comprising a computer, a trainee's desk and a training instructor's desk, and having a standby system, in the standby system computer, the inertia constant of the generator is M, the internal phase difference angle is δ,
The braking coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, the variation of the mechanical input of the generator is ΔPM, the time constant of the governor is TG, When the frequency characteristic constant is KG and the amount of frequency change is Δf, the equation of motion of the generator is expressed as (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (d
δ / dt) + P = PM, and the transient characteristic of the governor provided in the generator is set as TG · (dΔPM / dt) + ΔPM + KG · Δf = 0. Further, at least one of the trainee desk and the training instructor desk is a power system training simulator having a function of displaying the frequency calculation result.

[0007]

The object of the present invention is to simplify and speed up the frequency calculation process for simulating the operation of the system stabilization device, which is the main cause of the over-processing of the computer, so that the trainee does not feel uncomfortable. This is achieved by: The operation will be described while explaining the technical means employed in the present invention.

In order to accurately process the simulation of the operation of the system stabilizing device, the frequency calculation process considers transient phenomena and, for example, changes the frequency in units of 0.1 (Hz) every 0.1 to 0.3 seconds. Must be calculated in real time. However, when the required total load is obtained by using the AC method power flow calculation, which is a conventional technique, it has a large effect on the real-time processing of simulating a system accident or the like. Therefore, in the present invention, the total load is determined by simulating load shedding by the frequency relay operation in the frequency calculation process. As a result, it is possible to obtain the system frequency in consideration of the transient phenomenon in a short time. Further, utilizing the fact that the frequency calculation can be processed in a short time, for example, the load shedding by the frequency relay operation every 0.1 to 0.3 seconds and the simulation of the frequency fluctuation accompanying it, for example, a few seconds to several tens seconds ahead of the future The processing up to the processing is performed at one processing timing. Such a processing result is temporarily stored in a storage area in the computer, and simulation of a system is performed by sequentially accessing simulation data at corresponding times. In this way, by performing the frequency calculation for the future in advance, the simulation and processing of an accident multi-state change (referred to as the occurrence of a related operation when one accident occurs) such as the operation of a protection relay is overrun. The frequency of wrapping is kept low, computer processing is distributed over time, and computer loads are averaged. By the above processing,
Simulate the operation of the system stabilization device without giving the trainee a sense of incongruity, and "combination of frequency relay and CB state change"
It is possible to process the accident detection simulation by the high speed. As a result, when the standby computer in the multi-system is diverted as a training simulator, real-time processing can be performed in both the system simulation of the normal state and the system accident state, and the trainee can be trained in the same manner as the real system. It has become possible to provide a highly realistic training environment.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system configuration of a power system training simulator according to the present invention.

The power system training simulator comprises a computer 1, a system board 2, a trainee's desk 3, and a training instructor's desk 4. The system board 2 is a means for macro-monitoring the state of the entire power system, and is realized by various indicators such as the open / closed state of the main CB, electric power, reactive power, voltage, current and the like of main parts. In a conventional simulator for electric power system training, as shown in FIG. 2, the system simulation calculation processing means is constituted by a high-speed computer having a high throughput or an arithmetic processor. On the other hand, in the electric power system training simulator according to the present invention, since the frequency calculation processing in the system simulation calculation processing means can be speeded up, a dedicated computer is not required. Training instructor's desk 4
Has a configuration including input means such as a keyboard, output means such as a CRT, and the like. The instructor inputs various events such as various accidents and ON / OFF of the frequency relay through the input means, and performs an operation in the simulator to simulate an imbalance state of power supply and demand. . The trainee's desk 3 is configured to include, for example, input means such as a keyboard and output means such as a CRT. The trainee performs a plurality of operations via the input means in order to avoid the imbalance between supply and demand that has occurred. It is preferable that the time change of the main information such as the change of the supply and demand balance and the change of the power system frequency based on the operation is displayed on the output means. The time change of the main information may be displayed on an output unit provided in the training instructor's desk 4. FIG. 4 shows an example of a system simulation calculation flow according to the present invention. With respect to the conventional processing flow shown in FIG. 3, for example, a cycle of 0.1 to 0.3 seconds is calculated by predicting and calculating the frequency in consideration of the operation of the frequency relay up to ten and several seconds ahead at one processing timing. Alternatively, the frequency calculation in a short cycle such as one to several seconds, the simulation of the operation of the frequency relay, and the system simulation calculation in which the AC method power flow calculation processing and the like are performed are performed so that the training instructor and the trainee do not feel uncomfortable. The simulation can be performed with system simulation accuracy, for example, at a cycle of 10 seconds. This frequency prediction calculation will be described in detail. When a power supply and demand imbalance occurs between the power generation and the load due to some factor in the power system, a frequency change obtained by the supply and demand imbalance and the system characteristic constant occurs, but such a frequency change may occur immediately. Instead, the frequency fluctuates every moment due to various parameters such as the inertia constant of the generator and the operation delay of the governor control system (of the generator). For example, the frequency becomes steady after several seconds to several tens of seconds. In addition, in general, in the power system, a frequency relay that performs load control is installed to prevent accidents due to abnormal frequency fluctuations, and processing such as generator trip and load shedding is performed. Become. In the present invention, the frequency fluctuation when the supply and demand imbalance occurs is calculated in the range of 0.1 to 0.3 seconds, and at the same time, it is determined whether or not to operate the frequency relay. In the case of operation, each time the operation is performed, the frequency fluctuation due to the load rejection is similarly calculated, for example, in a range of 0.1 to 0.3 seconds, and these are sequentially synthesized, so that one calculation can be performed. For example, the entire frequency fluctuation of a few ten seconds ahead is predicted. Frequency fluctuations due to supply and demand imbalance are determined by the power supply and load system characteristic constants, generator characteristics, and governor characteristics, and various methods of simulating generator characteristics and providing governor models have been considered. , These are selected according to the required rigor.

In this example, a method for simulating the generator characteristics, which is one of the simplest examples, simulates the dynamic characteristics of the generator characteristics, the saliency, the transient characteristics of the field winding circuit, the damping winding, and the like by an approximate expression. As a transient model, the governor was approximated by a first-order delay of the time constant TG. Thus, the equation of motion of the generator is given by the following equation 1, and the transient characteristic of the governor is given by the following equation 2. (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (dδ / dt) + P = PM (Equation 1) (where M is the inertia constant of the generator, and δ is the internal phase difference Angular, D is the braking coefficient, ωn is the rated angular velocity, P is the electrical output of the generator, and PM is the mechanical input of the generator.) TG ・ (d ／ PM / dt) + ΔPM + KG ・ ＝ f = 0 2) (where ΔPM is the amount of change in the mechanical input of the generator, TG
Is the governor time constant, KG is the frequency characteristic constant of the power supply, Δ
f is the amount of frequency change) Here, assuming that a supply-demand imbalance has occurred due to a factor such as a power loss accident, if the conditions other than the supply-demand imbalance do not change, equations 1 and 2 are simultaneously established. By calculating the solution in this way, it is possible to easily predict the frequency fluctuation during the transition from immediately after the occurrence of the accident as shown in FIG. This frequency variation is, for example, 0.1 to 0.3
At the same time as calculating in seconds, it is determined whether to activate the frequency relay. The frequency relay has an operation frequency and an operation time set in advance, and is configured to operate when a frequency equal to or lower than the operation frequency (or “over”) continues for the operation time or longer.

For example, every time the frequency is calculated in the range of 0.1 to 0.3 seconds, it is determined whether or not the frequency of all the frequency relays deviates from the operating frequency. The departure continuation time is counted for the frequency relay that has deviated, and the departure continuation time is set to “0” for the frequency relay that has not deviated. The departure duration is
When the operation time becomes equal to or longer than the preset operation time, the frequency relay is operated, and the amount of load interrupted by the operation of the frequency relay is calculated.

The calculated interrupted load causes a new supply-demand imbalance. However, by calculating the frequency fluctuation caused by only the interrupted load by simultaneously formulas (1) and (2), the load is rejected. It is possible to predict the frequency fluctuation at the time of transition from 10 to several seconds later.

Assuming that a certain frequency relay operates after t1 seconds from the occurrence of the accident, at the time when the calculation is performed after t1 seconds,
A frequency change due to only the effect of load shedding as shown in FIG. 7B is predicted. Actually, frequency fluctuations due to supply-demand imbalance caused by an accident and frequency fluctuations due to load shedding occur. By combining these simulations, the total frequency change May be corrected as needed. In the above example, after t1 seconds, FIG. 7 (c) is a composite of FIG. 7 (a) and FIG. 7 (b).
As shown in the figure, since the frequency fluctuation is newly predicted, t
After one second, according to the newly predicted frequency fluctuation, the calculation of the frequency and the determination of the operation of the frequency relay are performed. As a result, when another frequency relay is newly operated, a frequency change is predicted by predicting the frequency fluctuation by the same method and further combining them. By such processing, finally, a frequency fluctuation as shown in FIG. 8 is predicted by the frequency prediction calculation. As described above, in the present invention, for example, 0.1 processing is performed at one processing timing.
With a width of up to 0.3 seconds, for example, a frequency transient change and a frequency relay operation state up to several tens of seconds ahead are determined. Also,
Information such as the frequency relay operated by the frequency prediction calculation, the operation time thereof, the cutoff CB, the cutoff load amount, etc.
The system is temporarily stored in a storage area in the computer, and the system simulation calculation process simulates the relay operation of the system with reference to this information. The various processing results described above may be displayed on a display device such as a CRT to improve the operability of the driver or the like. As described above, according to the present invention, first, the calculation result of the system frequency is converted to the CRT in real time in the same manner as the monitor of the real system.
And the like, and the sense of presence as a training simulator can be enhanced (calculation which conventionally required 5 to 10 seconds is completed within 1 second in the present invention).

Second, when an accident occurs, a transient curve of the system is calculated by frequency calculation, and a frequency transition from several seconds to several tens of seconds can be grasped, so that the timing of the relay operation can be known. This means that the frequency calculation which has been conventionally performed with a period of several tens of milliseconds (msec) need only be performed once when an accident occurs, and the calculation load at the time of simulating an accident is greatly reduced. Third, since frequency calculation can be performed by simple processing, functions such as frequency calculation can be improved even in a training simulator using a multi-system standby system. Therefore, in the case of the simulator using the standby system, it is possible to improve the functions such as performing the frequency calculation by the simulator in addition to the online business. Also, in the case of a simulator using a standby system, a configuration in which a simulator function is added on top of online work has a high processing load, and in many systems, only simple simulations can be performed. Can also be realized.

[0016]

According to the present invention, real-time frequency calculation processing can be performed in system simulations in both a normal state and a system accident state, and a dynamic training environment similar to a real system can be provided to a trainee. Can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system according to the present invention.

FIG. 2 is a configuration diagram of a conventional system.

FIG. 3 is an explanatory diagram of an example of a processing flow of a conventional system simulation calculation.

FIG. 4 is an explanatory diagram of an example of a processing flow of a system simulation calculation according to the present invention.

FIG. 5 is an explanatory diagram of operation simulation of the system stabilization simulation device.

FIG. 6 is an explanatory diagram of an accident detection simulation.

FIG. 7 is an explanatory diagram of a frequency prediction method.

FIG. 8 is a graph showing frequencies predicted by frequency prediction calculation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Computer, 2 ... System board, 3 ... Trainee's desk, 4 ... Training instructor's desk, 5 ... System simulation computer

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koetsu Tsushima 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Information & Control Systems Co., Ltd. (56) References JP-A-3-270646 (JP, A) JP-A-63-171123 (JP, A) JP-A-63-113487 (JP, A) JP-A-61-295831 (JP, A) JP-A-3-256526 (JP, A) JP-A-62-126830 (JP, A) JP, A) JP-A-6-19386 (JP, A) JP-A-61-270780 (JP, A) JP-A-4-369681 (JP, A) JP-A-63-64076 (JP, A) (58) ) Field surveyed (Int. Cl. ⁷ , DB name) H02J 3/00 G G09B 9/00 B G06F 15/20 D

Claims (4)

(57) [Claims] 1. A method for simulating the frequency of a power system, comprising the steps of: generating an event including an accident, an operation of a frequency relay, and a lapse of time; The inertia constant is M, the internal phase difference angle is δ, the damping coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, and the variation of the mechanical input of the generator is ΔPM. , Governor time constant TG, power supply frequency characteristic constant K
G, the amount of frequency change is Δf, and the equation of motion of the generator is (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (dδ / dt) + P = PM. The transient characteristics of the governor provided are
Assuming that (dΔPM / dt) + ΔPM + KG · Δf = 0, frequency fluctuation due to imbalance of power supply and demand is calculated at predetermined time intervals from the above equation (2).
At the same time, calculate the amount of load interrupted by the operation of the frequency relay.
To calculate the frequency fluctuation due to load shedding, and calculate the frequency fluctuation due to the imbalance in the demand and supply of power.
And frequency fluctuations due to load shedding.
A frequency simulation method for a power system, which calculates a frequency variation up to a predetermined time ahead . 2. A method for simulating the frequency of a power system having a standby system, wherein an event including an accident, an operation of a frequency relay, and an elapse of time occurs, and an imbalance occurs in power supply and demand. , The inertia constant of the generator is M, the internal phase difference angle is δ, the damping coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, and the mechanical input of the generator is Change amount ΔPM, governor time constant TG, power supply frequency characteristic constant K
G, the amount of frequency change is Δf, and the equation of motion of the generator is (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (dδ / dt) + P = PM. Assuming that the transient characteristics of the governor provided are TG · (dΔPM / dt) + ΔPM + KG · Δf = 0, frequency fluctuation due to imbalance of power supply and demand at predetermined time intervals is calculated from the above equation (2).
At the same time, calculate the amount of load interrupted by the operation of the frequency relay.
To calculate the frequency fluctuation due to load shedding, and calculate the frequency fluctuation due to the imbalance in the demand and supply of power.
And frequency fluctuations due to load shedding.
A frequency simulation method for a power system in which frequency fluctuations up to a predetermined time ahead are calculated by using a calculation means of a standby system. 3. A frequency simulation method for an electric power system according to claim 1, wherein a calculation result of the frequency is displayed on a display means. 4. A power system training simulator comprising a computer, a trainee's desk, and a training instructor's desk and having a standby system, wherein the standby computer has an inertia constant M of the generator, The phase difference angle is δ, the braking coefficient is D, the rated angular velocity is ωn, the electrical output of the generator is P, the mechanical input of the generator is PM, the variation of the mechanical input of the generator is ΔPM, and the governor time constant Is TG, the frequency characteristic constant of the power supply is KG, and the amount of frequency change is Δf, the equation of motion of the generator is expressed as (M / ωn) · (d ² δ / dt ² ) + (D / ωn) · (dδ / dt) + P = the PM, the transient characteristics of the generator provided is governor, as TG · (dΔPM / dt) + ΔPM + KG · Δf = 0, the two equations, at predetermined time intervals, the power supply and demand Frequency fluctuation due to unbalance
At the same time, calculate the amount of load interrupted by the operation of the frequency relay.
Te, the frequency variation due to load rejection calculated, varying the frequency by imbalance of supply and demand of the calculated power
And frequency fluctuations due to load shedding.
With this, it has a function of calculating the frequency fluctuation up to a predetermined time ahead , and further, at least one of the trainee's desk and the training instructor's desk has a function of displaying the calculation result of the frequency A simulator for power system training, characterized in that: