JPS5911736A - Transmission controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a conversion device and a DC line for converting power of an AC system including a generator whose output is restricted by an AIM node of a governor from transformed power to DC power or vice versa. The present invention relates to a control device for transmitting power to other AC systems via a plurality of DC power transmission systems including a power transmission system, a butterfly system, and a lil control system.

Conventionally, there has been a drug dispensing device of this type as shown in FIG. In Figure 1, 1a and 1b are AC systems including generators that can control the system frequency rl+12 by adjusting the governor, 2a and 2b are bus bars connected to AC system bowls 1a and 1b, and 5PL to 5d are thyristors. 4a connects the buses 1a and Ib through the converters 6a and 6b, and together with these, the 1 is a DC line forming a DC transmission system; 4b is a DC line connecting bus bars 2a and 2b via converters 3c and 6d, and together with these forming a DC transmission system of $J2; 5 is a system frequency of bus 2a; A detection circuit 6 for detecting r, adds the circular wave number signal outputted from the detection circuit 5 (referred to as circular wave number r to keep the explanation 1t11ton) and the reference river wave number fo with the polarity shown, III outputs the difference (signal) it (= tor,) between the two (15, 7a, 7b uses the difference Δr of the W adder 6 to control the thyristors of the converters 3t>, 5c,
Firing signal for arc cutting 7 n, p+ 7 bp
This is an ignition control circuit that outputs k.

Next, the operation will be explained. The frequency f of the bus 2a is detected by the detection circuit 5, and the reference frequency r is detected by the jnW device. The difference Δr from which the difference Δr is taken is the difference Δr from the ignition control circuit 7.
a, 7b, from which the repetition frequency and phase are corrected and nine firing signals 7δp, 7bp are output. The conversion devices 3a and 3c are activated by the ignition words 7PLp and 7bp.
The conversion of is controlled, and electric power P, , P flows from the AC system 1a through this.

Next, when a ground fault F occurs in the DC line 4a at time t1,
Due to the non-indicating protection device, the power P of the second DC power transmission system becomes zero as shown in FIG.

Therefore, the load on the AC system 1a is reduced, the rotation of the generator increases, and its frequency r increases. Frequency +7f,
, the difference Δr increases, and the phase of the firing control circuits 7a, 7bFi firing signals 7ap 17bp is controlled accordingly, so that the power I3. of the DC transmission system of I81 is increased. increases as shown in FIG. 2, and the load on the AC system 1a increases. Therefore, the number of starters in the AC system 1a is reduced by 1.
This suppresses the sudden rise in frequency f.

Typically, the response of a DC transmission system is faster than that of an AC system, including the source I'll. As shown in FIG. 2, when the first DC system is overloaded to suppress the increase in the frequency r of the AC system 1a, the accelerating force of the AC system 1a decreases, and the M wave number f
In order to restore the frequency f to the reference frequency f, the generator governor cannot be activated, and the DC transmission system continues to be overloaded.

Therefore, in the conventional power transmission control device, it is necessary to make each DC transmission system clear in advance so that it can withstand the continuous load, which is not economical, and also eliminates such overload. Is it like that? Even if I try to control the governor of the ff machine,
Before the IQ negative load is eliminated, the frequency of the AC system increases and the frequency relay is activated, resulting in the generator being disconnected.

This invention... This was created to eliminate the drawbacks of the conventional system as described above. When an overload is detected in the DC transmission system, the governor of the generating country is controlled by d5 using a signal indicating this overload to reduce its output. It is an object of the present invention to provide a power transmission control device that can eliminate overload in a DC power transmission system in a short time by reducing the power consumption.

An embodiment of the present invention will be described below with reference to the drawings. 48
In the figure, the same reference numerals as in Figure 1 indicate the same parts, 8a
, 8b is the converter [KfflI flowing to 15a, 5b, .
l? The current transformers 9a and 9b are the reference values Irθf, .I ref2 that set the overcurrent value of the currents I, , I, and the currents I, , 1 detected through the current transformers 8a and 8b. ．． All comparisons are made with I ref, (I, , l ref,
When detecting <I, output 'r-"1"
11 is a control circuit that outputs a deceleration signal 11a when the output of the OR gate 10 becomes wll. , 12 is a governor driven by the deceleration signal 11a.

Next, the operation will be explained. Conversion device 5a.

When the currents i,, t, flowing through 3b do not become @ currents, that is, when they are normal, overcurrent detection circuits 9a and 9b output 'fK
: Since it is set to 'o', the governor 12 maintains that state. However, when a ground fault F occurs in the DC protection circuit 4a at time t, the current I becomes an overcurrent, the overcurrent detection circuit 9h sets the output to 111, and a protection device (not shown) causes the overcurrent detection circuit 9h to set the output to 111. The power P of the DC transmission system becomes zero. For this reason, as explained in Figure 1, K and the direct M of Shizu 1.
The E-feed Tff and the power P of the system increase. Overcurrent detection circuit? When the output of b becomes 11, the output of the OR gate 10 also becomes 211, and the governor 12 is controlled by the control circuit 11 deceleration signal 11b to reduce the output of the generator m of the AC system 1a. Therefore, the frequency r of the AC system 1a decreases, and the power P of the first DC transmission system decreases as shown in FIG.
.

It will return to its original value and the overload condition will be resolved.

In the above embodiment, a case has been described in which overload is detected from the current of the AC system, but it may also be detected from the state of the DC line. Further, in the above embodiment, the overload detection result is given as a logical value, but the same effect as in the above embodiment can be obtained by using the overload detection result as an analog signal and controlling the governor according to this method. .

As described above, according to the present invention, when an overload is detected in the system, the governor is controlled based on the overload detection result so as to reduce the output of the generator of the system. Since it is possible to set the fixed wave number to a predetermined value and to eliminate overload of the DC power transmission system in a short time, the DC power transmission system can be configured economically.

44. Brief explanation of the drawings Figure 1 is a schematic diagram of the power transmission system to be controlled and a conventional power transmission control device. Figure 42 is a graph showing the response characteristics of the power transmission system by the power transmission control device shown in Figure 1. FIG. 3 is a schematic configuration diagram of a power transmission system to be controlled and a power transmission control device according to an embodiment of the present invention, and FIG. 4 is a graph showing response characteristics of the power transmission system by the power transmission control device shown in FIG.

1h, 1b-AC system, 'lh, 2b-bus, 6a-5
d... Conversion device fR, 4FL, 4b... DC line, 5
...Detection circuit, 6...Adder, 7a, 7b...Ignition control circuit, 8a, 8b...Current transformer, 9a, 9b...
・Overcurrent detection circuit, 10...OR gate, 12.-
・Governor. Note that the same reference numerals in the figures indicate the same parts.

Deputy Physician Nobu Kuzuno - (1 other person) C Figure 2 between the ribs 4th cap Continuation of page 1 ■Applicant: Mitsubishi Electric Corporation 2-2 Marunouchi, Chiyoda-ku, Tokyo number 3

Claims (1)

[Claims] '61 Including a DC line controlled power converter with ignition control
．． The output is controlled by a governor through several DC transmission systems.
Connect the first and second AC systems including the generator to be used,
In the power transmission control device that controls each power conversion device described above so as to match the system frequency number of the first AC system with the store quasi-circular number, a plurality of A power transmission control comprising: a load detection circuit; and a control circuit that controls a governor to reduce the output of the generator of the first alternating current system indicated in F based on the detection results of each of the overload detection circuits. Device.