KR102207942B1 - Design Method of DC electric railway power supply system including energy storage system - Google Patents

Abstract

The present invention relates to a method for designing a direct-current electric railway power feeding system including an energy storage system. According to the present invention, the method for designing a direct-current electric railway power feeding system comprises: a train driving data calculation step; a power feeding system equivalent circuit configuration step; and a simulation step. According to the present invention, a direct-current electric railway power feeding system can be designed in a more precise manner.

Description

Design Method of DC electric railway power supply system including energy storage system

The present invention relates to a method of designing a direct current electric railroad power supply system, and more specifically, reflecting various conditions that change according to train operation such as the number of trains, train weight, output, load current, and energy storage system. A DC electric railway power supply system design method including an energy storage system that can more accurately simulate the operation of the DC electric railway power supply system and analyze and predict various phenomena of the DC electric railway power supply system through analysis of the simulation results. It is about.

In general, the electric railway power supply system refers to an electrical system configuration in which power supply and power outages are possible by dividing the tram line into appropriate sections in consideration of the supply distance, voltage drop, and maintenance from a substation. Unlike general electric power systems, such an electric railway power supply system consists of a moving load that continuously repeats reverse, braking and stops for other lines, and does not stop at one place, and its position changes continuously, and operates within a substation section. Since the power consumption of each train is different for each train, the size of the load varies greatly.

Therefore, for safer and more accurate train operation, the voltage of the tram line must always be maintained within a certain range so that the vehicle can operate without abnormality, and the current capacity must also be designed to sufficiently withstand the load of the train.

In this way, in order to calculate the substation capacity or load of the DC electric railway power supply system, conventionally, the DC electric railway power supply system is analyzed through a simple calculation method by number calculation, and the analysis result is inaccurate.

Accurately calculate the number of trains, train weight, train type, train output according to the train type, load current of train, and various load fluctuation factors or load of each element according to actual train operation such as energy storage system. Difficulty, there is a problem in that the DC electric railway power supply system cannot be accurately analyzed.

The present invention was derived to solve the above problems, and reflecting various conditions that change according to train operation such as the number of trains, train weight, output, load current, and energy storage system. It enables a more accurate simulation of the operation, and analyzes and predicts various phenomena of the DC electric railway power supply system through the analysis of the simulation result, so that the DC electric railway power supply system can be designed more precisely.

In one aspect of the present invention for solving the above-described problem, predetermined train vehicle data, track data, and operating condition data are respectively input to perform train operation simulation through a TPS (Train Performance Simulation) program, and the TPS A train driving data calculation step of calculating train driving data including train vehicle location, driving time, power consumption, and regenerative power during a predetermined time interval through train driving simulation; Using the train vehicle data, DC power supply condition data, and train operation data together with the train driving data for the predetermined time interval calculated through the train driving data calculation step, the substation, the train, and the train during the predetermined time interval, A power supply system equivalent circuit configuration step of converting a direct current electric railroad power supply system including a tram line and an energy storage system into a node to be equivalent to an electric network; And the current value and voltage value of the substation during the predetermined time interval using a node equation for the electric network of the DC electric railway power supply system equivalent in the step of constructing the power supply system equivalent circuit, and a tram line at a predetermined train position. A simulation step of calculating simulation analysis data including a current value and a voltage value of; It provides a method for designing a direct current electric railway power supply system including an energy storage system characterized by including.

In a method for designing a direct current electric railway power supply system including an energy storage system according to an embodiment of the present invention, the train vehicle data includes each information on the number of vehicles per train unit, train weight, maximum speed, traction force, and braking efficiency. Including; The track data includes information on curvature, slope, tunnel, bridge, and overpass of the track; The driving condition data includes each information on a station location, a signal facility, a train facility, and a speed limit; The DC power supply condition data includes each information on a substation location, substation resistance, wiring resistance, and rail resistance; The train operation data may include each information on the interval and stop time,

Preferably, the train driving data calculation step, the power supply system equivalent circuit configuration step, and the simulation step are repeatedly performed for a predetermined period of time, and the energy storage system includes the DC electric railroad power supply system in the power supply system equivalent circuit configuration step. On the other hand, if the voltage value of the substation for a predetermined time interval calculated in the simulation step after the energy storage system is equalized to the electrical network is out of a predetermined range value, the next power supply system equivalent circuit configuration step It can be included in the direct current electric railway power supply system and equalized to the electric network.

The direct current electric railway power supply system including the energy storage system according to the present invention reflects various conditions that change according to the train operation such as the number of trains, train weight, output, load current, and energy storage system. The operation of the system can be more accurately simulated, and through analysis of the simulation results, various phenomena of the DC electric railway power supply system can be analyzed and predicted to more accurately design the DC electric railway power supply system.

1 is a block diagram schematically showing a direct current electric railway power supply system including an energy storage system according to an embodiment in a method of designing a direct current electric railway power supply system including an energy storage system according to the present invention;
2 is a method for designing a direct current electric railway power supply system including an energy storage system according to the present invention, comprising: an electric network equivalent to a direct current electric railway power supply system excluding an energy storage system;
3 is a method for designing a direct current electric railway power supply system including an energy storage system according to the present invention, comprising: an electric network equivalent to a direct current electric railway power supply system including an energy storage system; And,
4 is a flow chart showing a power flow calculation process for a direct current electric rail power supply system including an energy storage system according to an embodiment in the method of designing a direct current electric railway power supply system including an energy storage system according to the present invention; .

Hereinafter, embodiments of the present invention in which the above object can be realized in detail will be described with reference to the accompanying drawings. In describing the present embodiments, the same names and reference numerals are used for the same configuration, and additional descriptions thereof will be omitted below.

1 is a block diagram schematically showing a direct current electric rail power supply system including an energy storage system according to an embodiment in a method of designing a direct current electric rail power supply system including an energy storage system according to the present invention, and FIG. 2 is In the method for designing a direct current electric railway power supply system including an energy storage system according to the present invention, it is an electric network equivalent to a direct current electric railway power supply system excluding the energy storage system.

In addition, FIG. 3 is an electric network equivalent to a direct current electric railway power supply system including an energy storage system in the method of designing a direct current electric railway power supply system including an energy storage system according to the present invention, and FIG. In the method for designing a direct current electric railway power supply system including an energy storage system according to an exemplary embodiment, a flowchart showing a power current calculation process for a direct current electric railway power supply system including an energy storage system according to an embodiment.

In the method for designing a direct current electric railway power supply system including an energy storage system according to the present invention, first, a predetermined train vehicle data, track data, and operation condition data to be simulated driving are respectively input to a TPS (Train Performance Simulation) program, Train driving data calculation step of calculating train driving data including train vehicle location, running time, power consumption, and regenerative power during a predetermined time interval (one iteration) by executing the TPS, and the train driving data calculation step Using the train vehicle data, DC power supply condition data, and train operation data, along with the train driving data during the predetermined time interval calculated through the substation, train, tram track, and energy storage during the predetermined time interval. A node for the power supply system equivalent circuit configuration step of converting the DC electric railroad power supply system including the system into a node to be equivalent to the electric network, and the electric network of the DC electric railroad power supply system equivalent in the power supply system equivalent circuit configuration step And a simulation step of calculating simulation analysis data including current values and voltage values of the substation during the predetermined time interval and current values and voltage values of a tram line at a predetermined train location using the equation.

In the train driving data calculation step, train driving data including train vehicle location, operating time, power consumption, and regenerative power during a predetermined time interval are calculated using TPS (Train Performance Simulation), a specialized train operation simulation program. In a step of accomplishing this, predetermined train vehicle data, track data, and operation condition data are input as input data for the train operation simulation, and a simulation of train operation is performed.

The train vehicle data includes various train vehicle information such as the number of vehicles per train schedule, train weight, maximum speed, traction force, and braking efficiency, and the track data includes curvature, slope, tunnel status, bridge status, and, Various line information such as whether or not an overpass is included, and the driving condition data includes various driving condition information such as station location, signal facility, train facility, and speed limit, and is used for more accurate train operation simulation through the TPS.

In the DC electric railway power supply system, the position of the load and the amount of power demand change according to the operation of the train, and the change of the position of the load and the power consumption is not only calculated at a specific time snapshot as in the existing power system, but the operating condition is Analysis must be continuously performed during a specific repeated time interval (one iteration), and in the case of the present invention, the design of a direct current electric railroad power supply system is achieved through this analysis process.

In the step of configuring the power supply system equivalent circuit, using the train vehicle data, DC power supply condition data, and train operation data together with the train driving data for the predetermined time interval calculated through the train driving data calculation step. The DC electric railway power supply system including the substation, train, tram line, and energy storage system for a predetermined time interval is noded and equalized to an electric network.

The DC power supply condition data includes information on a substation location, a substation resistance, a wiring resistance, and a rail resistance, and the train operation data includes each information on a time interval and a stopping time.

1 is a block diagram schematically showing a direct current electric railway power supply system including an energy storage system according to an embodiment, excluding the energy storage system in the above configuration diagram, and including only an uplink train line among up and down train tracks It is possible to configure an equivalent electric network as shown in Fig. 2 for a simple direct current electric railway power supply system.

The simulation step includes the current value and voltage value of the substation during the predetermined time interval using a node equation for the electric network of the DC electric railway power supply system equivalent in the step of constructing the power supply system equivalent circuit, and at a predetermined train position. Simulation analysis data including the current value and voltage value of the tram line is calculated.

은 상기 열차 주행 데이터 산출단계에서 산출해 낸 열차 차량 위치에 해당하는 값으로 주어지며, I₁과 I₂가 결정되어 있으므로, 반복계산법을 이용하여 각 노드의 전압의 해를 구할 수 있다. Equation 1 is a node equation for the electric network, and Equation 2 is an equation representing a relationship between a voltage applied across the train and an equivalent impedance. Load

Is given as a value corresponding to the position of the train vehicle calculated in the train driving data calculation step, and since I ₁ and I ₂ are determined, the solution of the voltage of each node can be obtained using an iterative calculation method.

을 구한다.

의 값을 모르기 때문에 초기에는 직류 무부하 전압인 1,500V(또는 750V)로 가정하여

을 계산하여 [G]를 구하고 수학식 1을 풀어 [V]를 구한다. 이렇게 구한 new [V]를 갖고 다시

을 계산하여 [G]를 수정한 후 수학식 1을 다시 푼다. 이렇게 반복하여 old [V]와 new [V] 값의 차가 허용범위 내에 들어오면 반복계산을 끝낸다. In order to solve Equation 1, by Equation 2

Find

Since the value of is not known, it is assumed that the DC no-load voltage is 1,500V (or 750V).

Calculate [G] and solve Equation 1 to obtain [V]. With the new [V] obtained like this,

After calculating [G], the equation 1 is solved again. Repeatedly in this way, when the difference between the old [V] and new [V] values falls within the allowable range, the repetition calculation ends.

을 갱신하기 위하여 사용되는 수학식 2는 차량전압의 제곱에 관계된 식이기 때문에, 수렴속도가 늦고 반복계산이 많아지게 하는 단점이 있다. In the iterative calculation process of the above calculation

Since Equation 2 used to update is an equation related to the square of the vehicle voltage, there is a disadvantage in that the convergence speed is slow and repetitive calculations are increased.

In order to improve this, it is necessary to modify the form of the conductance matrix and the voltage and current matrix by equalizing a railroad vehicle as a current source. Using the relational expression of Equation 2, Equation 1 is improved to Equation 3 below.

This improvement of the node equation makes it less sensitive to voltage errors in the initial process of calculation because the relationship between power consumption and voltage is a primary relationship when I _veh is updated in the iterative calculation process. This appears to be an effect of decreasing the amount of calculation due to an increase in the convergence speed of the iterative calculation and a reduction in the number of iterations. In addition, since it is possible to distinguish the matrix between the nodes located on the auxiliary line and the nodes located on the rail, the burden of calculating the voltage matrix value for each calculation is reduced. The current vector iterative calculation algorithm is as shown in Fig. 4, and is expressed by the node equation of Equation 3 in the same form as in the case of the conductance matrix iterative calculation method.

으로 표현되었지만 전류벡터 반복계산에서는 차량의 노튼 등가 전류원으로 표현된다는 것이다.In the matrix form, [G]*[V] = [I], but the difference is that the equivalent circuit representing the vehicle load is calculated according to Equation 2 in the case of repeated calculation of the conductance matrix.

It is expressed as but is expressed as the Norton equivalent current source of the vehicle in the iterative calculation of the current vector.

가 '0'임을 알 수 있다. 상기 수학식 4에 의하여 [I]를 구하고, 상기 수학식 3을 풀어 [V]를 구하고, 이 [V]new를 이용해 [I]를 수정하여 다시 [V]를 구한다. 이렇듯 계산을 반복하여 [V]new 와 [V]old 의 차가 허용범위(voltage tolerance) 내에 들어오면 계산을 마치게 되며, 이 방법을 이용한 알고리즘은 도 4에 도시된 바와 같다.Compared to the case of iterative calculation of conductance matrix,

You can see that is '0'. [I] is obtained by Equation 4, [V] is obtained by solving Equation 3, and [I] is modified using this [V]new to obtain [V] again. When the difference between [V]new and [V]old is within the voltage tolerance by repeating the calculation as described above, the calculation is completed, and the algorithm using this method is as shown in FIG. 4.

On the other hand, the regenerative power generated by the railroad vehicle when braking is generated by the back electromotive force generated when the rotating machine is braking. Loads with frequent starting and braking, such as railway loads, generate a considerably larger amount of regenerative power compared to the power consumption. When the nth vehicle is braked, when the n-1th or n+1th vehicle starts, the generated regenerative power can be utilized, but when a nearby vehicle drives in another row, the generated regenerative power is consumed as heat. . Based on the characteristics of the railroad system, if regenerative energy generated by applying the energy storage system can be utilized, the energy efficiency of the railroad system can be remarkably improved.

The biggest characteristic that appears in the system due to the regenerative power generated from the braking vehicle is the fluctuation of the wiring voltage. Urban rail systems designed with a rating of 1,500 [V] vary greatly between 1,300 and 1,800 [V] due to the fact that they consume a lot of power at startup and generate regenerative power. Therefore, if the energy storage system is controlled for the purpose of suppressing fluctuations in the wiring voltage, the storage system can perform an operation capable of storing excess power and supplying insufficient power.

In the case of an energy storage system, it is calculated through input data that determines the range of charging and discharging voltages. The energy storage system determines its operation by monitoring the utility voltage. The operation of the energy storage system is divided into a charging mode that absorbs energy above a specific voltage and a discharge mode that releases energy below a specific voltage. In the case of the DC electric railway power supply system, the substation voltage changes very sensitively according to the driving mode of the vehicle driving near the substation. By monitoring the substation voltage, the power supplied from the substation can be calculated, and the substation cannot be used by other vehicles. It is possible to determine whether there is regenerative power flowing into the system.

3 shows an equivalent circuit in which the energy storage system modeled as a current source is additionally installed in consideration of the installation of the energy storage system in the substation, and the storage system current I _ess and the internal resistance g _ess of the storage system are in the substation, which is a Norton equivalent current source. As is added in parallel, the system matrix is newly constructed as shown in Equation 5 below.

전압을 고정하기위해

과

을 ∞값에 가깝게 설정하고 행렬을 계산한 후 고정된

값으로 새로운

값을 계산한다. 이후 기존

에서

을 빼서

값을 계산한다.When considering the energy storage system, the current analysis of the vehicle's position and driving mode is first performed every second, and then the voltage result of each substation is checked to see if it exceeds the input voltage limit. Likewise, the method of recalculation through matrix transformation was adopted. In other words,

To fix the voltage

and

Is set close to the value of ∞, the matrix is calculated, and the fixed

New by value

Calculate the value. Existing after

in

By subtracting

Calculate the value.

In the method for designing a direct current electric railway power supply system including an energy storage system according to the present invention, the train driving data calculation step, the train driving data calculation step, the power supply system equivalent circuit configuration step, and the simulation step are repeatedly performed for a predetermined time. , The energy storage system is equivalent to the DC electric railway power supply system in the power supply system equivalent circuit configuration step by excluding the energy storage system to an electrical network, and then the substation for a predetermined time interval calculated in the simulation step. When the voltage value of is out of the predetermined range value, the simulation step is performed after being included in the DC electric railway power supply system in the next step of constructing an equivalent circuit of the power supply system to be equivalent to an electric network.

4 is a flow chart showing a power current calculation process for a direct current electric railway power supply system including an energy storage system according to an embodiment in the method of designing a direct current electric railway power supply system including an energy storage system according to the present invention; In order to perform electric current calculation, first, a parameter of a Norton equivalent current source for each substation is defined using the electric power supply condition data, and the location data of the corresponding substation is stored. Using the vehicle data obtained from the TPS, the vehicle is placed in the corresponding position on the up and down lines. Node-ordering is performed using the location of the substation and the vehicle, and based on this, a non-zero component among the components of the system conductance matrix is determined. In addition, the conductance matrix of the system is constructed by multiplying the two distances and the impedance per unit length for a vehicle-vehicle or vehicle-substation that are directly connected electrically.

After constructing the conductance matrix of the system, all current analysis through iterative calculations is performed, and selecting an appropriate initial value for iterative calculations determines whether the iterative calculation converges or diverges, or when convergence And it is a very important process in that it can significantly reduce the calculation time. In the domestic DC city rail system, the wiring voltage is designed to operate with a rated voltage of 1,500V. Since the voltage of the substation and the vehicle is operated near the rated voltage, which is the design value, the initial value was set to 1,500V.

In the case of rail, it is used as a return path for the load current and is connected to the ground of the railway substation, so the operating potential is determined around 0V. Therefore, in the case of rail potential, it is initially set to 0V.

Using the initial value of the set current vector, the voltage vector is updated, and the entire iterative calculation determines that the solution has converged when the vector distance from the voltage vector of the previous step is less than a certain small value, Volt tolerance. And stop repetition.

After that, the allowable voltage range of the energy storage system, the regenerative voltage range of the regenerative inverter, and the maximum regenerative voltage range of the vehicle are analyzed. This is because the current value supplied from the substation varies, so it is necessary to fix the voltage at the upper or lower limit and calculate the current. The new voltage vector is updated with the recalculated conductance matrix. If the vector distance from the voltage vector in the previous step is less than a certain small value, Volt tolerance, it is judged that the solution has converged, and if it is not reached during the entire simulation time, return to the first step and repeat the calculation again. When the solution converges, the iterative calculation is stopped.

In the case of a DC electric railway power supply system, it is impossible to define a specific point in time for expressing a specific load condition because the movement of the vehicle is essential for the purpose of transporting passengers or cargo. Therefore, the power current calculation for the DC electric railway power supply system is performed by setting a time section for a predetermined time interval rather than a specific time point, and using the position and power consumption of each vehicle that changes during the predetermined time interval, Through the calculation process in one simulation step, the current vector matrix of the system is updated and a solution corresponding to the predetermined time interval is obtained.

As described above, the method of designing a direct current electric railway power supply system including an energy storage system according to the present invention reflects various conditions that change according to train operation such as the number of trains, train weight, output, load current, and energy storage system. It is possible to more accurately simulate the operation of the DC electric railway power supply system, and through the analysis of the simulation results, it is possible to design the DC electric railway power supply system more precisely by analyzing and predicting various phenomena of the DC electric railway power supply system. .

Although several embodiments have been exemplarily described above, the fact that the present invention can be embodied in various forms without departing from the spirit and scope thereof is obvious to those of ordinary skill in the art.

Accordingly, the above-described embodiments should be regarded as illustrative rather than restrictive, and all embodiments within the appended claims and their equivalents are included within the scope of the present invention.

11: KEPCO substation 12: DC subway substation
13: catenary 14: rail
15: train

Claims (3)

Train vehicle data, track data, and operating condition data are input respectively to simulate train operation through the TPS (Train Performance Simulation) program, and train vehicle location and operating time during a predetermined time interval through the train operation simulation of the TPS. , Train driving data calculation step of calculating train driving data including power consumption and regenerative power;
Using the train vehicle data, DC power supply condition data, and train operation data together with the train driving data for the predetermined time interval calculated through the train driving data calculation step, the substation, the train, and the train during the predetermined time interval, A power supply system equivalent circuit configuration step of converting a direct current electric railroad power supply system including a tram line and an energy storage system into a node to be equivalent to an electric network; And,
The current value and voltage value of the substation during the predetermined time interval using a node equation for the electric network of the DC electric railway power supply system equivalent in the step of constructing the power supply system equivalent circuit, and the current of the tram line at a predetermined train location A simulation step of calculating simulation analysis data including a value and a voltage value; A method of designing a direct current electric railroad power supply system including an energy storage system, comprising:
The method of claim 1,
The train vehicle data includes information on the number of vehicles per train schedule, train weight, maximum speed, traction force, and braking efficiency;
The track data includes information on curvature, slope, tunnel, bridge, and overpass of the track;
The driving condition data includes each information on a station location, a signal facility, a train facility, and a speed limit;
The DC power supply condition data includes each information on a substation location, substation resistance, wiring resistance, and rail resistance;
The train operation data includes each information on an interval and a stop time; A method for designing a direct current electric railway power supply system including an energy storage system, characterized in that.
The method according to claim 1 or 2,
The train driving data calculation step, the power supply system equivalent circuit configuration step, and the simulation step are repeated for a predetermined time,
The energy storage system,
In the step of constructing the power supply system equivalent circuit, the DC electric railway power supply system is equalized to an electric network excluding the energy storage system, and then the voltage value of the substation for a predetermined time interval calculated in the simulation step is a predetermined range value. In the case of deviating from the power supply system equivalent circuit configuration step, the DC electric railway power supply system design method comprising an energy storage system, characterized in that included in the DC electric railway power supply system and equalized to an electric network.

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