JPS5943372A - Apparatus for diagnosis of element obstacle of thyristor valve - Google Patents

Abstract

PURPOSE:To enhance space efficiency and economical effect, in a high voltage thyristor converter constituted by stacking thyristor valves in a plurality of stages, by performing the diagnosis of an element obstacle by a reduced number of microcomputers. CONSTITUTION:The voltage detecting sigansl au1-auN of thyristor valves U1 can be taken in a time sharing manner by a microcomputer MC and, after one or more logical data of voltage detection are taken in at every each value to be stored in an RAM circuit 22, the obstacle discrimination program preliminarily stored in an ROM circuit 24 is practiced to perform the discrimination of the element obstacles of the valves U1, X1. When the obstacle of a thyristor element is discovered, obstacle data such as an obstacle signal, the number of obstacles or the like are sent out as an output signal C from an I/O circuit 23. By this mechanism, the diagnosis of the element obstacle can be performed by a reduced number of the microcomputers and the enhancement in space efficiency and economical effect can be achieved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an element failure diagnosis device for a thyristor valve.
In particular, the present invention relates to an element failure diagnosis apparatus suitable for monitoring the states of all thyristor elements of a high voltage thyristor converter using a microcomputer or the like and diagnosing failures of the thyristor elements based on logical judgment.

[Technical background of the invention]

A large number of thyristor elements connected in series or series-parallel are used in high-voltage thyristor valves for DC power transmission, frequency conversion, etc. On the other hand, since thyristor elements may be damaged due to failure of themselves or the gate circuit tube, a predetermined number of thyristor elements are generally connected in series with a margin. Therefore, if a thyristor element fails and the number of failed elements reaches this number of margin thyristors, the thyristor valve is deemed inoperable and stopped.
It is necessary to replace the faulty thyristor element.

In order to carry out such maintenance, it is important to monitor failures of thyristor elements and to know the number of failure elements at all times.

In response to such demands, in recent years, thyristor element failure diagnosis apparatuses that apply microcomputers to monitor thyristor element failures have come into use. FIG. 1 is a block diagram of a well-known device failure diagnosis device, in which a voltage divider circuit 2 consisting of capacitors, resistors, etc. is connected in parallel to each of a plurality of thyristor elements S1 to SN.
A series circuit of a light emitting element 11 and a current limiting resistor 12 for detecting the forward applied voltage of SN is also connected in parallel.

On the other hand, the light emitting element 11 is equipped with a diode 13 for preventing reverse voltage.
are connected in parallel. Each power generating element 11 generates light when energized, and this optical signal is introduced into the failure diagnosis section 15 through the light guide 14 and converted into electrical signals a1 to aN by the photoelectric conversion circuit 16. The electrical signals a1 to aN become voltage detection signals output in response to voltage being applied to each of the thyristor elements S1 to SN. Each voltage detection signal a1 to aN is input to an OR circuit 17 and a latch circuit 21. The latch circuit 21 holds the voltage detection signals a1 to aN as data, and this data is stored in the RAM (random access memory) circuit 22 via the CPU (central processing unit) 25. ■/O (input/output) circuit 2
3 has the function of interfacing between the CPU 25 and the outside, while a ROM (read-on memory) circuit 24
has built-in programs for reading data and determining element failure. In addition, the latch circuit 21, CPU 25, RAM
The circuit 22, ROM circuit 24, and I/O circuit 23 together constitute a microcomputer section MC. By the way, the output signal b of the OR circuit 17 is given to the I/O circuit 23, which acts as a signal instructing the latch circuit 21 to read data. Further, the I/O circuit 23 outputs an element failure signal, the number of element failures, a failure element number, etc. as an output signal c.

In this configuration, when a forward voltage is applied to the thyristor bulb, if the thyristor element S1 is normal, the light emitting element 11 generates an optical signal, so the voltage detection signal a
1 produces an output "1" during the forward voltage period. On the other hand, if the thyristor element SN is out of order, for example, the light emitting element 11 does not generate an optical signal, so the voltage detection signal a
N will not generate an output "0". Further, among the thyristor elements S1 to SN, one of the voltage detection signals a1 to aN is output "1" by a normal thyristor element.
”, but this output is the output signal b of the OR circuit 17.
Set to “1”. The microcomputer section MC discriminates this output signal b via the I/O circuit 23 and generates a data read signal for the latch circuit 21. The launch circuit 21 stores each of the voltage detection signals a1 to aN at the time when the data read signal is generated as voltage detection logic data. In this case, if the voltage detection signals a1 to aN are "0", the data will be delivered as "0", and if they are "1", the data will be delivered as the data "1".

In this way, the voltage detection logic data stored in the latch circuit 21 is stored in the RAM circuit 22 under program control, and then the failure determination program in the ROM circuit 24 diagnoses an element failure. If, for example, an element failure is discovered as a result of the failure diagnosis, an element failure signal, the number of element failures, a failure thyristor number, etc. will be output from the I/O circuit 23 as an output signal c.

As described above, according to the configuration shown in FIG. 1, even though there are a large number of thyristor elements, it is possible to diagnose the failure of all the thyristor elements in the thyristor valve in a short time.

[Problems in the Background Art] By the way, as shown in FIG. 2(a), when the thyristor valves U1, V1, W1, X1, Y1, and Z1 are bridge-connected,
1, Y1, and Z1 are generally stacked in multiple stages. For example, as shown in FIG. 2(b), thyristor valves U1 and X1, thyristor valves V1 and Y1, and thyristor valves W1 and Z1 are each arranged in a two-tiered configuration. In such a case, the element failure diagnosis section 1 corresponding to each valve
5-U1, 15-X1, 15-V1, 15-Y1, 15
-W1 and 15-Z1 are provided, but two of each element failure diagnosis section 15-U1 to 15-Z1 must be placed near the bottom of the two-stage valve, so a large space is required near the bottom of the valve. . By the way, each valve U1~Z1
From there, optical signals are derived by the light guide 14, and these are connected to corresponding element failure diagnosis units 15-U1 to 15-Z1, respectively, as shown in FIG. 2(c), for example. Further, it is necessary to prepare the element failure diagnosis sections 15-U1 to 15Z1 in a number corresponding to the number of thyristor valves U1 to Z1, which increases cost and is not economical. Also,
Since the time required for fault diagnosis is short, the waiting time of the microcomputer MC becomes long, which hinders efficient operation.

[Purpose of the invention]

Therefore, an object of the present invention is to solve the problems of the prior art as described above, to be able to cope with a multi-tiered thyristor valve configuration with a compact and economically efficient structure, and to be able to provide an element failure diagnosis function. It is an object of the present invention to provide an element failure diagnosis device with excellent reliability that can detect this even when it occurs.

[Summary of the invention]

In order to achieve the above object, the present invention includes a plurality of thyristor valves each consisting of a plurality of thyristor elements and operating in different phases, and a plurality of thyristor valves each comprising a plurality of thyristor elements, each of which is configured to detect the voltage of each of the thyristor elements constituting each thyristor valve. A plurality of voltage detection means are provided corresponding to each thyristor valve, and the output of the corresponding voltage detection means is stored as data in accordance with the operation timing of each thyristor valve, and failure diagnosis of the thyristor element is performed based on the stored data. The present invention provides a device for diagnosing a thyristor valve element failure, which is equipped with a diagnosing means for performing the following.

[Embodiments of the invention]

Embodiments of the invention will be described below with reference to the drawings.

FIGS. 3(a) and 3(b) show a layout diagram and a block diagram of an element failure diagnosis apparatus according to an embodiment of the present invention. -UX1 is placed.

That is, one element failure diagnosis unit 15-UX1 is connected to each of the two stacked thyristor valves U1 and X1 via the light guide 14, and each thyristor valve U1
The voltage of each thyristor element detected by , X1 is introduced into the element failure diagnosis section 15-UX1 in the form of an optical signal.

Light guide 14 from each thyristor valve U1, X1
is connected to the photoelectric conversion circuit 16, and receives the voltage detection signals aU1 to aUN of the valve U1 and the voltage detection signal a of the pulp X1.
X1 to aXN are obtained. Note that the voltage detection signal aU1~
aUN is input to the OR circuit 17U, subjected to OR logic, and output signal bU1 is output to the I/O circuit 23. On the other hand, the voltage detection signals aX1 to aXN are input to the OR circuit 17X, subjected to OR logic, and output signal by1 is output to the I/O circuit 23. In addition, voltage detection signals aU1 to aUN
, aX1 to aXN are input to the latch circuit 21 as data. Microcomputer section MC is I/O circuit 23
Voltage detection signals aU1 to aU1, based on output signals bU1, bX1 of OR circuits 17U, 17X input via
AX1 to aXN are taken into the latch circuit 21 as data, and an element failure diagnosis operation is performed according to a failure diagnosis program built in the ROM circuit 24.

In this configuration, consider the case where a forward voltage is applied to the thyristor valve U1. In this case, OR circuit 17U
Since the output signal bU1 is input to the I/O circuit 23, the microcomputer section MC
Execute the data loading operation to. As a result, the voltage detection signals aU1 to aUN, aX1 to aXN are output to the latch circuit 2.
1 and stored as data in the RAM circuit 22. That is, at the time when a forward voltage is applied to the thyristor valve U1, the voltage detection signals aU1 to aUN are stored in the RAM circuit 22 as logic data for voltage detection. On the other hand, when a forward voltage is applied to the thyristor valve X1, at this point the output signal bX1 of the OR circuit 17X becomes I/
The voltage detection signals aX1 to aXN of the cyrisk valve X1 are input to the O circuit 23, and in the same way,
is stored as logical data for voltage detection.

In this case, the timing at which the voltage detection signals aU1 to aUN and the voltage detection signals aX1 to aXN are taken into the microcomputer section MC is as shown in the time chart of FIG. By the way, Fig. 4(a) shows the thyristor valve U1.
, the anode-cathode voltage waveform of the thyristor valve X1, (b) the anode-cando voltage waveform of the thyristor valve This is the timing of the output signal bX1.

In other words, one microcomputer unit MC receives the voltage detection signals aU1 to aU of the thyristor valve U1 in a time-sharing manner.
N and the voltage detection signal aX1 of the thyristor valve X1
aXN can be taken in, so there is no need to install a microcomputer for each thyristor valve U1, X1.

As described above, one or more pieces of voltage detection logic data are taken in for each valve, and after storing these data in the RAM circuit 22, a fault determination program stored in advance in the ROM circuit 24 is executed. , one thyristor element failure determination for each thyristor valve U1, X1 will be performed. When a failure of the thyristor element is discovered, a failure signal and failure data such as the number of failures are sent out from the /O circuit 23 as an output signal c.

As described above, the phases of the forward voltages applied to the thyristor valves U1 and X1 are different, so the output signals bU1 and bX1 of the OR circuits 17U and 17X receiving the respective voltage detection signals aU1 to aUN and aX1 to aXN Of course, the phases of are also different. Therefore, the microcomputer section MC is I
By inputting the signals bU1 and bX1 to the /O circuit 23, the voltage detection signals aUl to a of the thyristor valves U1 and X1 are
It is possible to read UN, aX1 to aXN as individual data. Also, the name thyristor valve U1, X1
Since the fault determination can be executed using the same fault determination program, the number of program steps does not increase.

Furthermore, instead of storing all the voltage detection logic data of the thyristor valves U1 and X1 in the RAM circuit 22 and then executing the element failure determination program, a series of operations of importing the voltage detection logic data and executing the element failure determination program are performed individually. It may be performed for each thyristor valve U1, X1. That is, one or more pieces of voltage detection logic data of the thyristor valve U1 are stored in the RAM circuit 22 by the output signal bU1 of the OR circuit 17U, and then a failure determination program regarding the thyristor valve U1 is executed to detect a failure of the thyristor element. After making the determination, one or more pieces of voltage detection logic data for the thyristor valve X1 are stored in the RAM circuit 22 using the output signal bx1 of the OR circuit 17X, and then a failure determination program regarding the thyristor valve X1 is executed to detect the thyristor valve X1. Performs element failure determination. By separately determining the failure of the thyristor valves 1 and 1 in this manner, it is possible to reduce the capacity of the RAM circuit 22.

As described above, according to the configuration shown in FIG. 3, one microcomputer unit MC can operate the two-stage thyristor valve U1.
, X1, and it is possible to realize an economical and structurally compact device.

Note that FIG. 5 shows a series connection configuration diagram of thyristor valve bridges each having a phase difference of 30 degrees in electrical angle, and the present invention is applicable to such thyristor valves U1, U2,
V1, V2, W1, W2, X1, X2, Y1, Y2, Z
It is also applicable to a so-called four-stage valve in which the valves 1 and Z2 are stacked in multiple stages.

Figure 6 shows U2, X2, and U in the thyristor valve in Figure 5.
Fig. 1 shows a layout diagram when the present invention is applied to a configuration in which 1 and X1 are stacked in four stages. FIG. 7 shows the voltage phase and forward voltage detection timing between the anode and cathode of each bulb in this configuration. By the way, Figure 7 (A) ~
(D) are thyristor valves U1, X1, U2, respectively,
Voltage waveform between each anode and cathode of X2, Fig. 7 (E)
~(H) are thyristor valves U1, X1, and U2, respectively.
, X2 shows the timing of forward voltage detection. In FIG. 6, 15-UX12 is an element failure diagnosis section that includes one microcomputer section MC.

As is clear from Fig. 7, the thyristor valve U1
1. U2 and X2 each have a phase difference of 180 degrees in electrical angle, and thyristor valves U1 and U2, and X1 and X2 each have a phase difference of 30 degrees in electrical angle.

Therefore, since the forward voltage detection timing of each thyristor valve U1, U2, X1, and X2 is different, one element failure diagnosis section 15-UX12 can import voltage detection logic data for each thyristor valve and perform element failure diagnosis. It is possible to do so.

On the other hand, each thyristor valve U1, U2. If the phase relationship between X1 and X2 is determined in advance, it is also possible to take in the following voltage detection logic data.

In other words, the thyristor valves U2 and U1 are 30° in electrical angle.
phase difference between thyristor valves U1 and X1 and U2 and X
If we pay attention to the fact that 2 is an electrical angle and there is a phase difference of 180°, we get
First, the forward voltage detection signal of the thyristor valve U2 at the time point (1) shown in FIG. 7(c), that is, the voltage detection logic data at the timing shown in FIG. It is sufficient to memorize the voltage detection logic data of the thyristor pulp U2 at a time point delayed by 30 degrees in electrical angle from the timing of G), that is, at the time point (2) in FIG. No forward voltage detection signal of valve U2 is required. Similarly, the timing of acquiring the voltage detection logic data of the thyristor valves X2 and X1 and the memory timing is set to a point 180 degrees later than the timing of FIG. 7(G), that is, the timing of FIG. 7(D) (3).
The time shown in Figure 7 (B) is 210 degrees behind the time shown in Figure 7 (B).
If we take the point shown in (4), the thyristor valve X2,
It is possible to take in each voltage detection logic data without using it for the forward voltage detection signal of X1.

Note that in the above explanation, the timing of capturing the voltage detection logic data of the other thyristor valves U1, X2, and X1 is determined based on the timing of the forward voltage detection signal of the thyristor valve U2. Even if the valve is used as a reference, it is possible to obtain exactly the same effect with only a different phase relationship. Moreover, such a timing setting method can be applied in exactly the same way to the case of a two-stage thyristor valve.

Further, in each of the above embodiments, the forward voltage of the thyristor element constituting the thyristor valve is used as the voltage detection signal, but a reverse voltage may also be used and exactly the same effect can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the thyristor valve is
In high-voltage thyristor converters configured in multi-stage or four-stage stacks, space efficiency has been achieved, making it possible to diagnose element failures with a small number of microcomputers.
This makes it possible to obtain an element failure diagnosis device with excellent economical effects.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a well-known element failure diagnosis device, Figure 2 (a) is a bridge connection diagram of a thyristor valve, and Figure 2 (a) is a bridge connection diagram of a thyristor valve.
b) is a layout diagram when the failure diagnosis device of FIG. 1 is applied to the connection of FIG. 2(a), and FIGS. 3(a) and (b) are element failures according to an embodiment of the present invention. FIG. 4 is a layout diagram and a block diagram of the diagnostic device, and a time chart for explaining the operation of the configuration shown in FIG. 3(b). Fig. 5 is a series connection configuration diagram of thyristor valves, Fig. 6 is a layout diagram when the present invention is applied to a configuration in which four of the thyristor valves in Fig. 5 are stacked in four stages, and Fig. 7 is a diagram of the arrangement of the thyristor valves in Fig. 6. It is a time chart for explaining the operation of the configuration. DESCRIPTION OF SYMBOLS 1... Thyristor element, 11... Light emitting element, 14...
...Light guide, 15...Element failure diagnosis section, 17.
...OR circuit, MC...microcomputer section, 2
1...Latch circuit, 22...RAM circuit, 23...
・I/O circuit. Applicant substitute 1 Boar 1 role Kiyo 1 Figure 12 Sakai 3 (0) Er 4

Claims (3)

[Claims] (1) A plurality of thyristor valves each consisting of a plurality of thyristor elements and operating in different phases, and a corresponding one for each thyristor valve to detect the respective voltages of the thyristor elements constituting each thyristor valve. and diagnostic means for storing the output of the corresponding voltage detecting means as data in accordance with the operation timing of each thyristor valve and diagnosing a failure of the thyristor element based on the stored data. A device for diagnosing a thyristor valve element failure. (2) The device failure diagnosis device according to claim 1, wherein the diagnostic means includes logic means for determining the operation timing of each thyristor valve based on the output of the voltage detection means. (3) Element failure diagnosis according to claim 1, characterized in that the diagnostic means includes means for determining the operation timing of each thyristor valve from the phase difference with the operation timing of a specific thyristor valve. Device.