JPH01255443A - Power controller for dc electric railway - Google Patents

Abstract

PURPOSE:To restrict the maximum demand power of a DC substation to a contract power or less by operating the control angle of a rectifier in response to an input power amount to a plurality of DC substations for supplying powers to electric railways. CONSTITUTION:Input power amount calculating means 22 calculates a variable W1 from a momentary power P by a formula I, while input power amount calculating means 23 calculates a variable W2 by a formula II, a power amount reference unit 26 sets a reference value WP meeting contract power, and they are applied to a logic circuit 24. The circuit 24 calculates the value PP of the input power of a thyristor recitifier 17 by a formula III, and outputs it to a calculator 27. When it tends to become W1>=WP or W2<=WP, the output voltage of the rectifier 17 is reduced by a reference value PP-P to regulate the power of its own substation. On the other hand, in case of W1<WP and W2<WP, the control angle of the rectifier 17 is set to '0 deg.', i.e., the control rate is set to '1', and the power factor of the power source is set to '1'.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention is directed to a power control device for a DC electric railway, particularly for supplying power from a plurality of DC substations to a common DC electric railway. The present invention relates to a DC electric railway power control device suitable for adjusting input power including other DC substations so that the maximum power demand of one DC substation does not exceed the contract power of that DC substation.

(Prior Art) In recent years, the power demand of DC substations of DC electric railways has increased significantly as the frequency of train operation and the number of vehicles in the train have increased. From the standpoint of managing electricity rates, in order to operate electric railways economically and reduce electricity charges, it is necessary to regulate the maximum electricity demand at DC substations so that it falls within a preset upper limit. This is extremely important.

Depending on the electric railway company, the total length of the track ranges from several tens of kilometers to several hundred meters. As the line length increases,
The number of DC substations that supply electricity to trains ranges from a few in some places to several dozen in some places. In an electric railway system, each DC substation is usually linked via a DC feeder line and operated in parallel.

The length of the track is short, 1t! ! When power can be supplied to trains from one or more substations, three-phase AC power is supplied from the electric power company at the receiving substation, and after step-down, each DC power is transferred to the electric railway company's own transmission lines. A system is adopted to transmit power to a substation.

However, when the total length of the line becomes long and power must be supplied to the feeder line from multiple DC substations, it is common to purchase AC power from the power company at several receiving points.

Electric power companies collect electricity charges from consumers at each receiving point. Electricity charges consist of a basic charge determined by the maximum power demand and a metered charge determined by the actual amount of power consumed. For this reason, power companies measure the maximum power demand for each customer in addition to the amount of power consumed. Electric power companies revise contracted power, or basic rates, based on applications from consumers or the previous year's maximum power demand. Based on this contract, consumers are required to limit their electricity consumption to 4% or less of the contracted electricity. For the total power demand 4-1, a method is adopted in which the instantaneous power is continuously integrated and the integrated value is returned to zero at every required time period (usually 30 minutes). Since the π required power is contracted assuming the power factor of the load to be 0.85, it can essentially be considered as a contract for the apparent power demand.

The actual basic charge is collected after calculating the average power factor of the load every month and converting the power factor from 0.85 to the average power factor using the following formula.

0.85 (For contracted electricity... (1) In the case of electric railway companies, the load fluctuates widely and the load factor is poor, so the basic charge of the annual contract accounts for a large proportion of the electricity bill. If the power receiving points are distributed in several locations,
The total amount of contracted power will be even greater than if electricity is purchased at one location. This is because the maximum power demand does not occur at the same time, and the point of maximum power demand moves toward the city center or the suburbs over time depending on the time of day.

In conventional DC substations, uncontrolled A-type silicon rectifiers are mainly used. Therefore, since there was no voltage control capability, each train was supplied with almost constant voltage power from a nearby substation, and as a result, surplus energy was left flowing.

Further, even when rectification is performed using a controllable thyristor rectifier, the relationship between the magnitude of the load of the rectifier and the magnitude of the output voltage is uniquely determined according to the maximum load capacity.

FIG. 8 is a circuit diagram for explaining a general electric railway DC substation system. As shown in the figure, the electric car 2 is supplied with DC power from the overhead contact line 1, and the return current flows through the rail 3. Two DC substations A and B are connected to the overhead contact line 1, each converting power from an AC system AC into DC and supplying the converted DC to the overhead contact line 1. Each DC substation A, B has a rectifier transformer 13, a silicon rectifier 14 for AC/DC conversion, and a heavy duty high speed circuit breaker 15.
．． It consists of 16. Note that the input AC power from the AC system AC is determined by the wattmeter 12 as apl based on the current and circuit voltage determined by the current transformer 11.

Now, when the electric car 2 is passing the 0 point directly below the DC substation A in a row, the load sharing between the two DC substations A and B is shown in FIG. Figure 9 shows the load characteristic curve L1 of DC substation A at point 0, and the load characteristic curve L2 of DC substation B.
, and the composite load characteristic curve L of both DC substations A and B.
3, is DC substation A the load? Ti style! 9, and DC substation B bears the load current IB, making the total load current I. This shows that a current of =IA+1B is supplied.

The load sharing between the two DC substations A and B is determined by the no-load voltage of the silicon rectifier 14, the voltage fluctuation rate, and the circuit resistance of the overhead contact line 1, and there is no room for adjustment.

As is clear from FIGS. 8 and 9, when the electric car 2 passes through the zero point directly below the DC substation A, the load current I
. The majority of this is borne by DC substation A.

As described above, according to the power supply system in which the DC substation itself does not have voltage control capability, the only option is to make settings assuming maximum power = 2.

However, in recent years, electricity consumers have shown strong interest in power management in order to reduce electricity charges, and have begun to perform detailed management. Electric railway companies are no exception to this. However, the power system of an electric railway company is unique in that the feeder system extends in a straight line, the trains serving as loads move along the feeder system, and the power is turned on and off frequently.

In order to deal with this problem, it is conceivable to replace the silicon rectifier in the DC substation shown in FIG. 8 with a silice rectifier to provide a voltage control function. From this perspective, consider a power system as illustrated in FIG. 10. In FIG. 10, a DC substation A rectifies alternating current from a rectifier transformer 13 with a thyristor rectifier 17 and supplies it to the overhead contact line 1 via heavy-duty high-speed circuit breakers 15 and 16.

Now, two DC substations A when the electric car 2 is passing the 0 point directly below the DC substation A in a row.

Figure 8 shows the load sharing for B. Figure 8 shows the load characteristic curve L1 of DC substation A at point 0 when the control rate is -1, the load characteristic curve L2 of DC substation B, and both DC substations A.
, B shows a composite load characteristic curve L3 of DC substation A, a load characteristic curve L4 of DC substation A when the control rate is 1, and a composite load characteristic curve L5 of DC substation A when the voltage is controlled.

Load current at DC substation A! '(1<1'<
lA) ＾ BA Then, DC substation B is made to bear the load current 1'(1<B■B'(IA'), and the total load current is 1.
'(-10) current is being supplied.

As is clear from FIGS. 10 and 11, by arranging the thyristor rectifier 17 on the DC substation A side to provide voltage control capability, the load current IA of DC substation A in FIG. By making DC substation A bear the load current IA' in place of the load current IB of B, and making DC substation B bear the load current 1 u', the share of the peak load is reduced. The capacity of the thyristor rectifier 17 of A can be smaller than that in the case where voltage control is not performed.

(Problem to be solved by the invention) According to the conventional power management method, it is not possible to control the output voltage to the feeder line at all, so power settings are made assuming the maximum power demand at each DC substation. Alternatively, the output voltage must be given uniquely as a function of the instantaneous value of the load. Therefore, there is no function to regulate the maximum power requirement of the DC substation to be less than the contract power, and furthermore, if voltage control is performed by controlling the phase of the rectifier, the power factor deteriorates.

Therefore, the present invention solves the problems of the prior art described above,
The object of the present invention is to provide a DC electric railway power control device that regulates the maximum power demand of a DC substation to the contracted power amount and enables economical power management.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention provides power adjustment means for detecting input power of a DC substation that supplies power to a DC electric railway, and instantaneous power detected by the power adjustment means. a first power amount calculation means that continuously calculates a first dissipation representing the amount of power obtained when the power is integrated over the total required time period at a constant sampling period; and an instantaneous amount detected by the power adjustment means. a second power amount calculation means that continuously calculates a second variable representing the amount of power obtained when the power is integrated over a time period shorter than the total demand time period at a constant sampling period; A standard value setting means for setting a standard value of power consumption corresponding to the power consumption, and a first variable and a second variable representing the power amount are compared with the standard value of power consumption to determine the input power of the rectifier of the DC substation. an input power standard calculation means for calculating a reference value of the input power;
The present invention is characterized in that it includes a power adjustment means that performs phase control of the rectifier according to the value, lowers the output voltage of the rectifier, and suppresses input power.

(Function) According to the present invention, the input power to the DC substation is detected, this is integrated in each of the two time periods, and these are compared with the allowable power, and based on the results of this comparison, the DC substation The load on the substation is reduced by operating the rectifier of the substation and controlling the voltage. Thereby, it is possible to provide a function of adjusting load sharing between the rectifier of the own substation and the rectifier of the adjacent substation operated in parallel via the feeder line.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram of a power control device according to an embodiment of the present invention. In the same figure, an input power detection unit 21 detects instantaneous power p (t) from the power value detected by a wattmeter 12 and supplies it to a first power amount calculation unit 22 and a second power amount calculation unit 23. . The first power amount calculation unit 22 calculates a first time variable W1(t) representing the power amount obtained when the instantaneous power p (t) is integrated over a period of demand time T with a sampling period ΔT as W, , ( t)-Wl (-ΔT) + IP(t)
-P(t-T)) ΔT ...... Continuously calculates based on the calculation formula (2), and then calculates this in the logic circuit 2.
Give to 4. On the other hand, the second electric power calculation unit 23 calculates the electric power obtained when the instantaneous electric power P The second variable W2(t) representing the amount of time is defined as W (t)-W2 (t-ΔT) + IP(t)-
P(t-T)l ΔT . . . Continuously calculates based on the calculation formula (3)
give to The electric energy standard value setting unit 26 sets a standard value W commensurate with the contract electric power P based on the condition p W , P ΦT (4)C, and sends this to the logic circuit 24. give. The logic circuit 24 logically operates the first variable W(t), the second variable W2(t), and the reference value W, which are the above input signals, to determine the reference value P of the input power of the thyristor rectifier 17.
(t) as P (L) −f (W , W
(L), W2(L))9 pl (5) The calculation is performed based on the following function, and the result is sent to the subtracter 27 as a reference value. The subtracter 27 subtracts the instantaneous value P([) of the input power from the reference value P([), and the difference P(
L)-P(L) is given to the gate control section 25 to perform gate control of the thyristor rectifier 17.

Variable W ([) that represents the actual amount of electricity with respect to the reference value W
If w increases and w, (t)≧W, ・・・・・・・・・(6) or W2(t)≧W, ・・・・・・・・・(7), The reference value P(t)-P(t) of the control angle of the thyristor rectifier 17 is determined by the thyristor rectifier 1.
The power of substation No. 0 is adjusted by lowering the output voltage of No. 7, while the variable Wi(
t) is wl(t)<w, ・・・・・・・・・(8
), and W2(t) decreases Wp ・・・・・・・・・(9)
When it becomes, the control angle of the sirisk rectifier 'a17 is set to 00.
That is, the $11 ga factor is set to "1" and the power factor on the power source side is set to "1".

By the way, it is clear that the closer the power factor of the load is to "1", the better from the viewpoint of contract power. However, when the phase of the thyristor rectifier 17 is controlled, the power factor generally deteriorates.

On the other hand, this embodiment was developed by focusing on the fact that the average power factor is calculated monthly from the apparent power amount and the a-dynamic power amount in the power contract.

Note that in the configuration of FIG. 1, the power control device is shown in a discrete form for each functional block, but the implementation of the present invention is not limited to this, and can also be configured as a system using a computer. . FIG. 3 is a block diagram of a power control device according to another embodiment of the present invention constructed from this viewpoint. In the figure, A/D converter 37
The input power detection unit 21 converts the instantaneous power P (t) calculated from the power value detected by the wattmeter 12 into a digital value, and supplies this to the microcomputer 38 .

The power amount reference value setting unit 26 sets a reference value W 2 commensurate with the contracted power P 2 based on the condition of equation (4), and provides it to the microcomputer 38 as a digital value. The microcomputer 38 continuously calculates the time variable W1(t) representing the amount of power obtained when the input instantaneous power P (L) is integrated over the period of the demand time T at the sampling period ΔT based on equation (2). The instantaneous power P input while calculating
Continuously calculates the time variable W2(t) representing the amount of electricity obtained when (t) is integrated over a time period k·T shorter than the demand time period T with a sampling period ΔT based on equation (3), Next, a reference value Pp(t) of the input power is calculated from the variable W, (t), the variable W2(t), and the reference value WI), and this is compared with the instantaneous value P(t) of the input power, and the thyristor rectifier 17 Calculate the control angle of

This control angle is given to the gate control section 25 to perform gate control of the Sirisk rectifier 17.

FIG. 2 shows a control flowchart of the microcomputer applied to the configuration of FIG. 3, and particularly shows a control flow that is repeated every sampling period ΔT. For the sake of simplicity, we assume that the maximum snow power reduction is already in operation and that the sampling period Δ
It is assumed that a predetermined sequence is executed every T.

In step S1, the system is initialized and the process moves to the next step S2. In step S2, the instantaneous power P in the sampling period is read, and in the next step S3, the first variable W1. n ””Wl, n-1+(p-p)ΔT). After that, the process moves to n n-s step S4 and the second variable W2. . (-W
+(P − P , )ΔT).

2, n-1n n-3 In the next step S5, the first variable W1. n as the reference value W
If it does not exceed the standard value, step S8'
and the second variable W21. is compared with the reference value -W. Here too, if it is determined that the reference value is not exceeded, there is no need to regulate the input power, so the next step S12
Set the input power reference value P to the maximum allowable input power value P in Step
Return to pO tube S2. In addition, in the calculations in steps S3 and S4, the first variable W1, the second variable W, , , , of the power demand in the sampling period n is calculated as W from the power flowing into the AC winding side of the rectifier 1, n transformer, respectively. -W + (P-P)ΔT1,n
1. n-1n nm・・・・・・・・・(1
0) w −w + (p−p,) ΔT2,
n2. n-1n n-J・・・・・・
...(U) can be found. Here, m-T/ΔT1j is strictly m, O<k<1.

On the other hand, if it is determined in step S5 that W,n>W, then in step S6 the second variable W2. Compare n with the reference value -W. As a result, the second variable W2.
. If does not exceed the reference value, proceed to step S9,
The reference value P of input power is set to P, and it is determined in step SllO whether or not this set value exceeds the maximum allowable input power n''+value P. If it is not exceeded, the process proceeds to step S2. Return.On the other hand, the set value P of the reference value P is the input power p
If the maximum allowable value P of n-s is exceeded, step 912
Then, the set value is set to P and the process returns to step S2.

p.

In the determination in step S6, the second variable W2. n is the reference value.
If it exceeds W 2 , the sequence moves to step S7, where the value obtained by multiplying the reference value Wp of input power by the sampling period ΔT is compared with P 2 . As a result of this comparison, if W*ΔT does not exceed Pn, . On the other hand, if it is determined in step S7 that W*ΔT exceeds P, the process moves to step S9, and the reference value P of input power is set to P.

p n-■ In the determination in step S6, the second variable W2. . is the standard value -
If W has not been exceeded, the sequence moves to step S9. On the other hand, in the determination in step S8, the second variable W2. If it is determined that n exceeds the reference value -W, the process moves to step SIO.

Note that step S9. It is determined in step Sll whether or not the input vehicle power reference value P set by the SIO exceeds the maximum allowable input power value P.

If not, the process returns to step S2. On the other hand, the reference value P
The setting value of the maximum allowable input power P is p

If it exceeds pO, the set value is changed to P in step S12.
The process returns to step S2.

O The configurations of the above embodiments make it possible to suppress the power consumption of electric railways, and typical suppression characteristics in this case are shown in the characteristic diagrams of FIGS. 4 to 7. FIG. 4 is a time chart showing an example of data obtained when the negative 6:I current of a silicon rectifier for an electric railway was actually measured for 8 hours from around 5 am. Further, FIG. 5 shows a time chart of the required power required by calculation from the data in FIG. 4.

On the other hand, FIG. 7 shows the suppression characteristics when the contract power is 2500 Kv and -0.5. Here, it is assumed that a silice rectifier is used as the rectifier. Figure 6 shows the load current of the thyristor rectifier at this time, which was calculated using the previous data and the C simulation. By controlling the load current of the device, the actual input power is dynamically and significantly suppressed.

In addition, in each of the above embodiments, the case where the Cyrisk rectifier is applied to one of a plurality of DC substations is illustrated, but if the Cyrisk rectifier is applied to all DC substations, It is also possible to create a system with .

〔Effect of the invention〕

As described above, according to the present invention, the voltage of the rectifier is adjusted according to the amount of power input to a plurality of DC substations that supply power to electric railways. Even if the power demand at the DC substation exceeds the contracted power by operating the IJ power supply, it is possible to suppress this reliably, and it is necessary to connect the electric power to the own substation through the power line. It can be equipped with a function to adjust load sharing with other substations that are operated in parallel.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a power control device for DC electric iron m according to an embodiment of the present invention, FIG. 2 is a 70-chart of control according to the configuration of FIG. 3, and FIG. FIGS. 4 to 7 are characteristic diagrams for explaining the power usage suppression characteristics in the configurations of FIGS. 11 and 3, and FIG. Figure 9 is a circuit diagram to explain the DC substation system of a general electric railway. Characteristic diagrams to explain the load sharing of DC substations A and B. Section 10 is a circuit diagram of a general electric railway DC substation system i4-Zyristor rectifier L5 is applied, and Fig. 11 is an electrical Fee is the 7th
The 6 points immediately below the DC 1 substation in the figure are connected in a row; I4+,
There is a characteristic diagram S to explain the load distribution of the target areas A and B in 2.). 1...Tram line, 2...Electric train, '3...Rail 2
．． 11... Current transformer, 12... Power meter, 13... V
! Current transformer 1
...Input power detection unit, 22, 2"4...Power amount calculation unit, 24...Logic circuit, 25...Gate control unit:
'), 6... Electric energy reference value determining section, 38... Microcomputer. Applicant's agent Sato - Yukyo - IgJ Former Figure 10 C Evil - 〇 - \, 1-- rtsu-''

Claims (1)

[Claims] A power detection means for detecting the input power of a DC substation that supplies power to a DC electric railway, and a power amount obtained when the instantaneous power detected by the power detection means is integrated over the entire demand period at a constant sampling period. 1st to represent
a first power amount calculation means that continuously calculates a variable of , and a second power amount calculation means that represents the power amount obtained when the instantaneous power detected by the power detection means is integrated over a time period shorter than the demand time period in the sampling period. a second power amount calculating means for continuously calculating a variable of the amount of power; a reference value setting means for setting a reference value of power consumption commensurate with the allowable value of input power; a first variable representing the power amount; input power reference calculation means for comparing a second variable with the power consumption reference value to calculate a reference value for input power of a rectifier of the DC substation; A power control device for a DC electric railway, comprising a power adjustment means for controlling the phase of the rectifier according to the reference value of the input power to lower the output voltage of the rectifier and suppress the input power when the input power exceeds the reference value. .