JP2008059128A - Power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure the power source switching time of a real system without being affected by the characteristics of a switch or signal propagation delay between devices. <P>SOLUTION: Power supply voltage detection signals "Va", "Vb" and "Vn" to be respectively output from transformers 5a, 5b and 6 are fetched by a measurement device 8, and sampling hold processing, A/D conversion processing, data storage processing, difference voltage amplitude value arithmetic processing, difference voltage data storage processing, product variation arithmetic processing, comparison decision processing, and power supply switching time arithmetic processing are executed so that it is possible to measure a power supply switching time(excess duration). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power system that selects power supply voltages supplied from a plurality of power supplies and supplies them to a load, and more particularly to a power system that determines whether a power supply switching operation is good.

  For example, in the Shinkansen power supply system, there are substations every several tens of kilometers, and high-speed switching is executed in about 300 ms (250 to 350 ms) each time the power supply destination substation is switched.

  FIG. 3 is a block diagram showing an example of a power supply system having such a plurality of power supply systems.

  The power supply system 101 shown in this figure is provided with a plurality of AC power supplies 102a and 102b for supplying a power supply voltage, and a plurality of AC power supplies 102a and 102b for opening and closing a main contact according to an input opening / closing instruction. The switches 103a and 103b, the control device 104 that opens and closes the switches 103a and 103b according to the power supply voltage, and when the switches 103a and 103b are opened and closed by the control device 104, the switches And a measuring device 106 that measures the power switching time based on the open / closed state of each of the auxiliary contacts 105a and 105b provided in 103a and 103b.

  Then, the control device 104 selects one of the AC power supplies 102a and 102b, for example, the AC power supply 102a, closes the switch 103a, and loads the load on the path of the AC power supply 102a → the switch 103a → the load 107. When any abnormality occurs in the AC power supply 102a while the power supply voltage is supplied to the power supply 107, an opening instruction is issued to the switch 103a to cut off the connection between the AC power supply 102a and the load 107 and to be determined in advance. After the power failure time, the switch 103b is instructed to close, the AC power supply 102b and the load 107 are connected, and the power supply voltage is supplied to the load 107 through the path of the AC power supply 102b → the switch 103b → the load 107.

  By the way, in such a conventional power supply system 101, the power supply switching time changes due to changes in the characteristics and aging of each device and circuit constituting the power equipment. Therefore, the control device 104 opens and closes the switches 103a and 103b at a preset period, and the measuring device 106 moves the auxiliary contacts 105a and 105b in the same manner as the main contacts of the switches 103a and 103b. The contents of opening and closing are taken in to check whether the power switching time is in the normal range.

  However, in such a power supply switching time measuring method, since there is a difference in operation between the main contacts and the auxiliary contacts 105a and 105b provided in the respective switches 103a and 103b, the actual system power supply switching time is accurately measured. There was a problem that I could not.

  In addition, since the operating characteristics of the switches 103a and 103b, the operating characteristics of the auxiliary contacts 105a and 105b, and the like change due to deterioration over time, it is difficult to manage the accuracy of the switching time on the actual circuit. there were.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a power supply system capable of accurately measuring a power supply switching time of an actual system without being influenced by characteristics of a switch or a signal propagation delay between devices. It is said.

  In order to achieve the above object, the present invention provides two power supplies, a control apparatus that executes selection control of the two power supplies, and a power supply voltage that is output from each power supply by performing on / off according to a selection instruction of the control apparatus. In a power supply system equipped with a switch that selects any of the above and supplies it to a load, a difference voltage calculation that calculates a difference voltage between the power supply voltage on each power supply side and the power supply voltage on the load side to which the power supply voltage is supplied And a power supply switching determining means for calculating a difference between the current differential voltage obtained by the differential voltage calculating means and the previous differential voltage, and determining whether the selection device is switching power based on the difference; It is characterized by comprising a power switching time calculating means for measuring a time during which the selection device is determined to be switching power by the switching determining means and obtaining a power switching time.

  In this case, the power supply switching determination unit determines that the selection device is in a power supply switching operation when the following expression is satisfied.

ΔV product ^1syc > ^kΔV product ^1syc
However, ΔV product 1 ^syc : product change amount ^{serving as a} power supply switching index ^kΔV product 1 ^syc : preset reference value

  According to the present invention, it is possible to accurately measure the power supply switching time of an actual system without being influenced by the characteristics of the switch or the signal propagation delay between devices.

  FIG. 1 is a block diagram showing an embodiment of a power supply system according to the present invention.

  The power supply system 1 shown in this figure is provided with a plurality of AC power supplies 2a and 2b for supplying a power supply voltage, and a plurality of AC power supplies 2a and 2b that open and close a main contact according to an input opening / closing instruction. According to the state of the switches 3a and 3b, the power supply voltage, the control device 4 that opens and closes the switches 3a and 3b, and the switches 3a and 3b and the AC power supplies 2a and 2b. A plurality of transformers 5a and 5b for transforming each power supply voltage supplied from each AC power supply 2a and 2b and outputting power supply voltage detection signals “Va” and “Vb”, and switches 3a and 3b A transformer 6 inserted between the load 7 and transforming the power supply voltage to output a power supply voltage detection signal “Vn”, and a power supply voltage detection signal “Va” output from each of the transformers 5a, 5b, 6 ”,“ Vb ”,“ Vn ”, and measure the power switching time And a device 8.

  The control device 4 includes a control board on which a control program or the like is installed, and selects one of the AC power sources 2a and 2b, for example, the AC power source 2a, closes the switch 3a, and turns on the AC power source 2a. When the power supply voltage is supplied to the load 7 through the path of the switch 3a → the load 7, when switching from the AC power supply 2a to the AC power supply 2b, the switch 3a is instructed to open and the AC power supply 2a In addition to shutting off the load 7 and after a predetermined power failure time, the switch 3b is instructed to close, and the AC power source 2b and the load 7 are connected, so that the AC power source 2b → the switch 3b → the load 7 A power supply voltage is supplied to the load 7 through the path.

In addition, as shown in FIG. 2, the measuring device 8 includes an input conversion means 9, a sampling hold means 10, an A / D conversion means 11, a digital data storage means 12, a differential voltage amplitude value calculation means 13, The input conversion means 9 including the differential voltage data storage means 14, the product change amount calculation means 15, the comparison determination means 16, and the power supply switching time calculation means 17 is output from each transformer 5 a, 5 b, 6. The power supply voltage detection signals “Va”, “Vb” and “Vn” are taken in and converted to analog values.

  The sampling hold means 10 samples and holds each analog value obtained by the input conversion means 9 at a constant period.

  The A / D conversion unit 11 performs A / D conversion on each analog value sampled and held by the sampling and holding unit 10 and converts it into a digital value. The digital data storage unit 12 stores each digital value obtained by the A / D conversion unit 11.

Differential voltage amplitude value computing means 13 takes in the digital values stored in the digital data storage means 12, (1) below, (2) performs an operation shown in the expression, the voltage difference "△ Va ^n", “ΔVb ⁿ ” is obtained.

Differential voltage data storage means 14, a new differential voltage at the differential voltage amplitude value computing means 13 "△ ^Va n", each time the "△ Vb ^n" is obtained, captures this, FIFO (First In First out) method stores in the previous differential voltage stored ^{"△ Va n", "△} Vb n" previous differential voltage ^{"△ Va n-1syc",} is output as ^{"△ Vb n-1syc".}

Product change amount calculation means 15, this differential voltage obtained by the differential voltage amplitude value computing means ^{13 "△ Va n", "} △ Vb n" and the previous differential voltage output from the differential voltage data storage means 14 " “ ^ΔVan−1syc ” and “ ^{ΔVbn −1syc} ” are taken in and the calculation shown in the following equation (3) is performed to obtain the product change amount “ΔV product ^1syc ”.

The comparison determination unit 16 compares the product change amount “ΔV product 1 ^syc ” obtained by the product change amount calculation unit 15 with a preset reference value “ ^kΔV product 1 ^syc ”.

The power switching time calculating means 17 measures the time (excess continuation time) in which the comparison determining means 16 determines that the product change amount “ΔV product 1 ^syc ” exceeds the reference value “ ^kΔV product 1 ^syc ”. Then, the power supply switching time (excess continuation time) is calculated.

^{△ Va n = Va n -Vn n} ... (1)
ΔVb ⁿ = Vb ⁿ −Vn ⁿ (2)
However, △ Va ^n: difference voltage △ Vb ⁿ of the AC power source 2a side: AC voltage difference Va ⁿ of the power supply 2b side: power supply voltage Vb ⁿ of the AC power source 2a side: AC power supply 2b side power supply voltage value Vn ^n: Load supply voltage value supplied to 7 △ V product ^{1syc = | △ Va n × △} Vb n |
− | ^{ΔVa n−1 sy} × ^{ΔVb n−1 syc} | (3)
However, ||: absolute value sign △ V product ^1Syc: product variation at the power supply switching indication △ Va ^n: AC power source 2a of the differential voltage (current)
ΔVb ⁿ : differential voltage on the AC power supply 2b side (current)
^ΔVan-1sync : Differential voltage on the AC power supply 2a side (previous)
^{ΔVb n-1 syc} : differential voltage on the AC power supply 2b side (previous)
Then, each switch 3a, 3b is opened / closed by the control device 4, and the power supply voltage is supplied to the load 7 through one of the AC power supplies 2a, 2b, for example, the path of the AC power supply 2a → the switch 3a → the load 7. When the switch 3a is instructed to open, the AC power source 2a is disconnected from the load 7, and after a predetermined power failure time, the switch 3b is instructed to close. When the AC power source 2b and the load 7 are connected and the power source voltage is supplied to the load 7 through the path of the AC power source 2b → the switch 3b → the load 7, the measuring device 8 causes the transformers 5a, 5b, 6 to The output power supply voltage detection signals “Va”, “Vb”, “Vn” are fetched, and sampling hold processing, A / D conversion processing, data storage processing, differential voltage amplitude value calculation processing, differential voltage data storage processing, product Change calculation processing, comparison Constant process performs power switching time calculation processing, to measure the power switching time (excess duration).

Next, how to determine the reference value “ ^kΔV product ^1syc ” will be specifically described with reference to FIG. (A) to (e) shown in FIG. 3 indicate one cycle (sampling time) when the power source is switched.

If the power supply voltage detection signal “Vn” is 80% (= 24 kV) or more in a system with a rated voltage of 30 kV, it is determined that Vn = voltage exists. The power supply voltage detection signals Va and Vb are assumed to have a phase difference of 90 degrees, and the voltage values are not the same. Furthermore, a slight error occurs between the power supply voltage detection signals “Va” and “Vn” (the same applies to Vb and Vn) depending on the measuring device and the auxiliary transformer, but in this example, the error is 0 (the error range is (Depends on any setting.)
In this state, the product change amount “ΔV product ^1sync ” in each of the cycles (a) to (e) can be obtained as follows.

<< In the case of cycle (a), cycle (b) >>
ΔVa ⁿ = ^{Va n} -Vn ⁿ
= ^{Va n} -Va n
= 24-24 = 0
ΔVb ⁿ = Vb ⁿ −Vn ⁿ
= ^{Vb n} -Va n
= Vx
ΔV product ^{1syc = | ΔVa n × ΔVb n} |
− | ^{ΔVa n−1sync} × ΔVb ^n−1sync |
= | 0 × Vx | − | 0 × Vx |
= 0
<< In the case of cycle (c) >>
ΔVa ⁿ = ^{Va n} -Vn ⁿ
= 24-0
= 24
ΔVb ⁿ = Vb ⁿ −Vn ⁿ
= 24-0
= 24
ΔV product ^{1syc = | ΔVa n × ΔVb n} |
− | ^{ΔVa n−1sync} × ΔVb ^n−1sync |
= | 24 × 24 | − | Vx × 0 |
= -576
<< In the case of cycle (d) >>
ΔVa ⁿ = ^{Va n} -Vn ⁿ
= 24-0
= 24
ΔVb ⁿ = Vb ⁿ −Vn ⁿ
= 24-0
= 24
ΔV product ^{1syc = | ΔVa n × ΔVb n} |
− | ^{ΔVa n−1sync} × ΔVb ^n−1sync |
= | 24 × 24 | − | 24 × 24 |
= 0
<< In the case of cycle (e) >>
ΔVa ⁿ = ^{Va n} -Vn ⁿ
= ^{Va n} -Vb n
= Vx
ΔVb ⁿ = Vb ⁿ −Vn ⁿ
= ^{Vb n} -Va n
= 24-24 = 0
ΔV product ^{1syc = | ΔVa n × ΔVb n} |
− | ^{ΔVa n−1sync} × ΔVb ^n−1sync |
= | Vx × 0 | − | 24 × 24 |
= 576
As can be understood from the above equations, as shown in cycles (a), (b), and (d) shown in FIG. 3, if the product change amount “ΔV product ^1syc ” is the same as that before 1 syc, the change amount is 0. Further, when Vn becomes 0 as in the cycle (c), the ΔV product ^1syc becomes a negative value (−576). Further, when Vn becomes a rated value from 0 as in the cycle (e), the ΔV product ^1syc becomes a positive value (576).

Therefore, the setting of the kΔV product 1 ^syc starts counting when it becomes a negative value from 0, and stops counting when it becomes a positive value from 0.

  As described above, in this embodiment, the power supply voltage detection signals “Va”, “Vb”, and “Vn” output from the transformers 5a, 5b, and 6 are acquired, and the sampling hold process and the A / D conversion process are performed. , Data storage processing, differential voltage amplitude value calculation processing, differential voltage data storage processing, product change amount calculation processing, comparison judgment processing, power supply switching time calculation processing, so as to measure the power supply switching time (excess duration) Therefore, it is possible to accurately measure the power supply switching time of the actual system without being affected by the characteristics of the switches 3a and 3b, the signal propagation delay between the devices, and the like.

Further, in this embodiment, using the equation (1) to (3), together with determining the product variation "△ V product ^1Syc", this product variation "△ V product ^1Syc", is set in advance Since “ΔV product 1 ^syc > ^kΔV product 1 ^syc ” is established between the reference value “ ^kΔV product 1 ^syc ” and the reference value “ ^kΔV product 1 ^syc ”, it is determined that the power supply is being switched. It is possible to simplify, and the power supply switching time of the actual system can be accurately measured in real time without being influenced by the characteristics of each switch 3a, 3b, the signal propagation delay between devices, and the like.

It is a block diagram which shows one form of the power supply system by this invention. It is a block diagram which shows the detailed structural example of the measuring device shown in FIG. It is explanatory drawing which shows the setting method of reference value "k ( ^DELTA) V product ^1syc ". It is a block diagram which shows an example of the power supply system known conventionally.

Explanation of symbols

1: Power supply system 2a, 2b: AC power supply 3a, 3b: Switch 4: Control device 5a, 5b: Transformer 6: Transformer 7: Load 8: Measuring device 9: Input conversion means 10: Sampling hold means 11: A / D conversion means 12: Digital data storage means 13: Difference voltage amplitude value calculation means (difference voltage calculation means)
14: Differential voltage data storage means 15: Product change amount calculation means 16: Comparison determination means (power supply switching determination means)
17: Power switching time calculation means

Claims (2)

Two power supplies, a control device that executes selection control of the two power supplies, and an open / close that performs on / off according to a selection instruction of the control device and selects one of the power supply voltages output from each power supply and supplies the load to the load In a power supply system equipped with
Differential voltage calculation means for calculating a differential voltage between the power supply voltage on each power supply side and the power supply voltage on the load side to which the power supply voltage is supplied;
Power difference determination means for calculating a difference between the current difference voltage obtained by the difference voltage calculation means and the previous difference voltage, and determining whether the selection device is switching power based on the difference;
A power switching time calculating means for measuring a time during which the selection device is determined to be in power switching by a power switching determination means and obtaining a power switching time;
A power supply system characterized by comprising: The power supply system according to claim 1,
The power supply switching determination unit determines that the selection device is in a power supply switching operation when the following expression is satisfied:
ΔV product ^1syc > ^kΔV product ^1syc
However, ΔV product ^1syc : product change amount ^{serving as a} power supply switching index ^kΔV product ^1syc : preset reference value

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