JP3152725B2 - Control device of AC / DC conversion system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a DC power transmission system or an AC / DC conversion system used for a frequency conversion device.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional AC / DC conversion system, wherein 1 is a transformer for a converter, 2 is a thyristor converter, 3 is a DC reactor, 4 is a gate pulse generator, and 5 is a gate pulse generator.
Is a 12-phase control device, 6 is a converter common control device, 7 is an AC power detection circuit, 8 is a constant power control (APR) circuit, 10 is an accommodating power amount setting value calculation circuit, and 11 is an emergency accommodating power amount setting value operation. Circuit, 12 is a changeover switch, 13 is a previous value holding circuit, 14 is a direct control device that outputs a set value of the exchange power amount a, a set value of the emergency exchange power amount b, an emergency interchange power command signal c, and an emergency power interchange direction signal d. , 15 is an AC system having a frequency of 60 Hz, and 16 is an AC system having a frequency of 50 Hz.

The actual configuration of the converter common control device 6 shown in FIG. 3 (both the A system and the B system are the same), as shown in FIG. 4, includes a CPU 17, a memory 18, a timer 20, an interrupt control circuit, and the like. 21, a digital input circuit 22, and a serial communication circuit 23.

When a pulse is generated at a constant period by the timer 20, a signal is input from the interrupt control circuit 21 to the CPU 17, and the program stored in the memory 18 executes the timer interrupt program shown in FIG. First, the higher-level direct controller 14 outputs the interchangeable power amount set value a to the systems A and B of the converter common control device 6, and the interchangeable electric energy set value calculation circuit 10 converts the normal interchangeable power command value Pdp. calculate.

Next, the output power of the converter is detected from the AC power transducer, and a first-order lag operation (APR operation) for constant power control is performed so that the normal interchange power command value Pdp is equal to the interchange power amount. The calculation result is output as a current command value Idp of the 12-phase control device 5.

The 12-phase control device 5 is a converter common control device 6
The constant current control is performed so that the current command value Idp received from the inverter and the AC or DC current of the AC / DC conversion system become equal, and an appropriate phase control signal is output to the gate pulse generator (PG).
4 is output. The gate pulse generator 4 gives a gate pulse to the thyristor converter 2. With such a control system, an AC system 15 having a frequency of 60 Hz and a frequency of 50 Hz
Of the electric power between the AC systems 16.

[0007] Now, the operation in the case of flexible emergency power between two AC systems integration 1 5,16 below. The converter common control device 6 receives the emergency interchange power signal set value b from outside.
(50 Hz AC system 16 to 60 Hz AC system 15
When accommodating to 60Hz AC system 15 to 50Hz
The emergency interchange power amount set value for the interchange to the AC system 16 is input separately), the emergency interchange power command signal c , the emergency interchange
When a power direction command signal d (indicating a direction in which power is exchanged between the AC system 16 having a frequency of 50 Hz and the AC system 15 having a frequency of 60 Hz) is input, the emergency interchange power signal set value b at that time is calculated by the arithmetic circuit 11. The emergency interchange power set value e converted by the above is selected by the emergency interchange power direction command signal d, and is added to or subtracted from the interchange power amount set value a. The result of addition or subtraction is held by the previous value holding circuit 13 and the output is switched by the changeover switch 12 to calculate the emergency power command value in an emergency. The power control of the thyristor converter 2 is performed according to the emergency power command value in an emergency. In FIG. 2, f is a set value of the A system emergency interchange power amount, g is an A system emergency interchange power command signal, h is an A system emergency interchange power direction command signal, i is an A system final interchange power amount, and k is a B system interchange. Power amount set value, l is B system emergency interchange power amount set value, m is B system emergency interchange power command signal, n
Is the B-system emergency interchange power direction command signal, o is the B-system final interchange power, p is the A-system / B-system external input signal, q is the A-system external read signal, r is the B-system external read signal, and t1 is the interchange power. The amount setting value output timing, t2, is the emergency accommodation power amount setting value, the accommodation power command signal, and the emergency accommodation power direction command signal output timing.

[0008]

The control device of the conventional AC / DC conversion system described above has an independent structure so that the A system and the B system are not affected by each other. In the case of asynchronous operation, the timing of the calculation result is shifted. That is, in FIG.
At the timing t1 as shown in FIG. 2, when the setting change of the accommodating power amount set value a is changed to the B system, the emergency accommodating power set value b, the emergency accommodating power command signal c, and the emergency accommodating direction signal d are changed as shown in FIG. When input at the timing t2, the A system calculates the final accommodation power amount command value i from the normal accommodation power amount setting value a (pd) and the emergency accommodation power amount setting value b at the timing t1. Since the B system is delayed once by reading of the emergency power setting value b, emergency emergency power command signal c, and reading of the emergency power accommodation direction signal d, the interchange power setting value a before the time t1 is set. The calculation result of the final interchange power command value held in the A system and the B system for calculating the final interchange power amount o from the a (pd) and the emergency interchange power set value b is different. The converter common control device 6 outputs the power interchange direction and the interchange power command value to the host direct control device according to the calculation result. In some cases, the power interchange direction is reversed between the series and normal operation can be continued. There is a problem that disappears.

Generally, the emergency interchange power command is input from the upper direct control panel 14 when the frequency of the system to be interchanged fluctuates (decreases). If operation cannot be continued, there is a risk that the operation of the power system will be seriously hindered.

An object of the present invention is to provide a control device for an AC / DC conversion system which solves the above-mentioned problem and which always outputs the same operation result to an external control signal in a multiplex converter common control device which operates asynchronously. With the goal.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, the control of the accommodating power of the plurality of AC / DC converters is performed in at least a double system configuration, and each configuration is operated asynchronously. In the control device of the AC / DC conversion system,
An input means for inputting the accommodating power amount set value, the emergency accommodating power amount setting value, the emergency accommodating power direction command signal, and the emergency accommodating power command signal, and calculating means for computing the accommodating power command value; the computed within the converter control equipment <br/> interchange power command value, and a communication means for exchanging the system each other, the
Emergency interchange power direction command signal for emergency interchange power direction
Of the interchangeable power command value calculated by the calculating means.
Selection means for selecting the maximum value serving, selected by the selection means
Varying the respective systems the-option value as a final flexibility power command value
Output means for outputting to the converter control device .

[0012]

According to the invention corresponding to the first aspect, at least the final accommodating power reading timing of the duplex system is different, so that a case where the internal calculation result (final accommodating electric power amount) differs between the series occurs. Also in this case, the converter common control device of each system always outputs the same value by the selection means, so that the power interchange can be reliably performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the description of the same parts as in FIG. 3 is omitted. Here, the description will be focused on the system A, but for the system B, A and B may be read. 3 through the input circuit 22 (FIG. 4) for inputting the accommodating power amount set value a, the emergency accommodating power amount value b, the emergency accommodating power direction command signal d, and the emergency accommodating power command signal c. An arithmetic circuit for calculating the command value, for example, the CPU 17 (FIG. 4), and a serial communication circuit 23 (FIG. 4) for mutually exchanging the data of the internal interchange power command value between the respective converter control devices 6 (FIG. 4). And a selection circuit 9 for selecting the data exchanged by the serial communication circuit 23 and the accommodating power command value calculated by each control device by an external signal, and using the output of the selecting circuit 9 as a final accommodating power command value. It comprises an output circuit for outputting, for example, a serial communication circuit 23 (FIG. 4).

The operation of the present invention will be described with reference to FIG. A
The means for outputting the internal operation result of the system to the B-system converter common control device and the means for inputting the operation result from the B-system converter common control device to the A-system converter common control device are exchanged.

When an emergency interchange power amount set value b, an emergency interchange power command signal c, and an emergency interchange power direction command signal d are externally input to the A system and the B system, the internal calculation results of the A system and The operation result of the B-system converter common controller is used as an emergency interchange power direction command signal.
The maximum calculation result in the direction of the emergency interchange power is selected and output according to d .

FIG. 1 shows the serial communication circuit 23 of FIG. 4 which outputs the internal calculation result of each system between the series to the other series converter common controller and inputs the calculation result from the other series converter common controller. And a selection circuit 9 for selecting and outputting the internal calculation result and the calculation result from the other system converter common control device by the emergency interchange power direction command signal d.

The operation of the embodiment constructed as described above will be described below. In the normal operation state, the value obtained by calculating the accommodating electric energy set value a of the output of the upper direct control device 14 of each of the A and B systems by the accommodating electric energy set value calculation circuit 10 is output. When the emergency interchange power direction command signal d is input, the selection circuit 9 sets the maximum value in the emergency interchange power direction between the A system operation result and the B system operation result to the emergency interchange power direction command. Judgment is made based on the signal d and output selectively. In one row, 50 Hz from the 60 Hz side AC system during normal operation.
From the state in which 100 MW of power is supplied to the 60 Hz side AC system,
Change to 150MW in z AC system side, 50 from further 60Hz side AC system by simultaneously pressing interchange power command signal c
An example in which 100 MW power is urgently supplied to the Hz AC system will be described.

In this case, as described above, the one-way previous value holding circuit 13 holds 100 MW before the change,
The final output is 200 MW obtained by adding the 100 MW of emergency power, and the previous value holding circuit 13 of the other system outputs the changed 1
Hold 50 MW and add the amount of emergency
When the power becomes 0 MW, according to the present invention, both systems select and output 250 MW, which is a large value in the power interchange direction, and the outputs between the streams match.

According to the above-described embodiment, since the final interchange power reading timings of the A and B systems are different, even when a case where the internal calculation result (final interchange power amount) differs between the series occurs. , A-system, and B-system converter common control devices 6 always output the same value by the selection circuit 9, so that there is an effect that the power interchange can be surely implemented.
In the example of FIG. 1, the case of the double system has been described, but the same applies to the case of the triple system or more.

[0020]

As described above, according to the present invention, in the multiplex converter common control device, even if there is a shift in the timing of reading an external signal between sequences in an emergency such as when the frequency is lowered, the multiplex converter is controlled. An AC / DC conversion system that can match the interchangeable power command value of the converter common device, can continue operation of the AC / DC conversion system, and is highly reliable due to the multiplex system. Can be provided.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing an embodiment of a control device of an AC / DC conversion system according to the present invention.

FIG. 2 is a timing chart of the calculation of a command value of an interchangeable electric energy in FIG. 1;

FIG. 3 is a control block diagram showing an example of a control device of a conventional AC / DC conversion system.

FIG. 4 is a block diagram showing the converter common control device of FIGS. 1 and 3; DESCRIPTION OF SYMBOLS 1 ... Transformer transformer, 2 ... Thyristor converter, 3 ... DC reactor, 4 ... Gate pulse generator, 5 ... 12 phase control device, 6 ... Converter common control device, 7 ... AC power detection circuit, 8 ... Constant Power control (APR) circuit, 9 ... selection circuit, 1
0: accommodating electric energy set value calculation circuit, 11: emergency accommodating electric power set value arithmetic circuit, 12: changeover switch, 13: previous value holding circuit, 14: direct control device, 15: frequency 60 Hz
AC system of 16 ... AC system of frequency 50 Hz, 17 ...
CPU, 18 memory, 20 timer, 21 interrupt control circuit, 22 digital input circuit, 23 serial communication circuit.

Claims (1)

(57) [Claims] 1. A method for controlling interchange power of a plurality of AC / DC converters,
Each structure in the at least two redundant system configuration in the control device of the AC-DC conversion system for asynchronous operation, interchange power amount setting value, the emergency power interchanged amount set value, an emergency power interchanged direction command signal input for inputting an emergency interchange power command signal input via the means, and calculating means for calculating the flexibility power command value, the power interchanged command value calculated inside the converter control equipment of each system, and a communication means for exchanging the system mutually, the emergency accommodation Emergency interchange power method by power direction command signal
Of the interchangeable power command value calculated by the
Selecting means for selecting the maximum value of the above , and output means for outputting the value selected by the selecting means as a final interchangeable power command value to the converter control devices of the respective systems. Control device.