SU650158A1 - Electric power transmission system - Google Patents

Description

FIG. 1 is a schematic block diagram of a device for transmitting electrical energy pockets, and FIG. 2 and 3 show embodiments of a summing amplifier with an integrator in feedback.

1 transformer substation

2- first power system,

3- weak AC coupling,

4- second power system,

5- converter setting current setting unit,

6- current controller,

7- measuring frequency converter

8- summing amplifier,

9- integrator

/ - the rectified current setting, Id - rectified current.

The converter station / adjoins the first power system 2. Power system 2 is also adjoined by a weak link 3 connecting power systems 2 and 4. The input of the frequency converter 7 is connected to the AC side of the converter /. The output of the frequency converter 7 through a summing amplifier 8 is connected to the input of the converter's current setting block 5. The output of the summing amplifier 8 through the integrator 9 is connected to the second (non-inverting) input of the summing amplifier 8.

The device works as follows. Changes in the load in power systems 2 or 4 cause fluctuations in the exchange power of the weak link 3 and frequency in the node adjacent to the power system 2. Measured Hbie frequency deviation from the nominal through the summing amplifier 8, block 5 forming the current setting of the converter and regulator 6 current control the power of the converter /. The output of the frequency converter 7 produces a signal proportional to the frequency deviation from the nominal value and an interference (drift) signal. The drift of the circuit is compensated by the integrator 9, and the signal at the output of the summing amplifier with frequency deviations equal to zero is always zero. Frequency changes in the transient mode are transmitted to the controller input, since the time constant of the integrator 9 is chosen for a much longer period of weakly coupled electromechanical oscillations (on the order of 100 s). As a result, the passband of the auxiliary controller captures the frequency range of electromechanical oscillations and the frequency range of the primary control.

An embodiment of the summing amplifier fig. 2 uses one operational amplifier with an inverting and noninfluencing resonator. In pic nt

FIG. 3, uses two operational amplifiers with inversion of the strong in each of them.

In order to stabilize the weak communication mode, a controlled converter of a rectifying or inverter substation of direct current transmission or controlled converters of industrial consumers are used. At the same time, the range of auxiliary regulation should not exceed the permissible limits, determined either by the overloading safety system: With the property of the valves, or by the technological process to the consumer of electricity. As studies have shown, the required range of auxiliary adjustment of the converter, if its nominal power and throughput of a weak link are of the same order of magnitude, when using the proposed device is not more than 1-2% of the nominal power of the converter.

The economic effect of the proposal depends on the scale of implementation, the capacity of the installation and the number of hours of use of the installed capacity.

The costs associated with the implementation of the proposal are small and reduce to the costs of additional elements of the regulator. The implementation of the proposal is possible primarily in power systems that have powerful direct current transmissions.

Claims (2)

1. The UK patent number 1295855, cl. H 2 F, 1966. 2. Patent of the USSR No. 376978, cl. H 02 J .I / I6. 1969