JPH0454832A - Rotary system linkage unit - Google Patents

Abstract

PURPOSE:To realize quick power control by varying the magnitude and the phase of a voltage internally induced by the flux in the secondary circuit of rotor through cycloconverter control. CONSTITUTION:Upon variation of power or terminal voltage of a wound-rotor induction machine 2, a power control signal 14 and a voltage control signal 18 are fed to a frequency converter 8 which then controls the magnitude of an AC exciting current flowing through an AC excitation winding 7 and the phase of the terminal voltage based on a voltage detection signal 15 while simultaneously calculates a slip frequency based on the voltage detection signal 15 and a rotational speed detection signal 20 and controls the frequency of AC exciting current flowing through the AC excitation winding 7 to follow up the slip frequency. Since the magnitude and the phase of a voltage to be induced by the flux in the secondary circuit of rotor can be controlled quickly, the terminal voltage can be regulated quickly based on the variation of magnitude on the internally induced voltage and the power can be regulated quickly based on the variation of the phase of the internally induced voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a rotary interconnection device for controlling passing power between power grids.

(Prior Art) Conventionally, as a rotary interconnection device, a synchronous motor IA and a synchronous generator IB are connected by a direct connection shaft 3 as shown in FIG. There is a synchronous frequency converter of constant ratio frequency conversion type selected equal to . In order to control the passing power, this converter uses an armature moving device that can move either armature in the circumferential direction to adjust the load angle! 101. Since this armature moving device 101 operates mechanically, it is originally impossible to control high-speed passing power, and
It is useless when there is an urgent need for power interchange between countries. In addition, 5A and 5B in the figure are automatic voltage regulators (AVR)
, 6A, 6B are field windings.

(Problem to be solved by the invention) A supply and demand imbalance occurs in one of the interconnected power systems,
It would be preferable from the viewpoint of stable operation of the system if the rotating interconnection device could also perform high-speed control of the passing power when emergency accommodation from another power system is required due to system stability or frequency fluctuation problems.

The present invention was made in response to the above-mentioned requirements, and an object of the present invention is to provide a rotating grid interconnection device that enables high-speed power control.

[Structure of the invention]

(Means for solving problem 8) A wound induction machine uses a frequency conversion device such as a cycloconverter to generate a secondary current in its secondary winding that has a slip frequency that is the difference between the frequency on the power system side and the rotor frequency. By controlling the magnitude and phase of the current, the generation or consumption of active power and reactive power can be controlled at high speed. In other words, even if the rotation speed of the rotor changes, the cycloconverter can be controlled to always follow the frequency of the secondary current as the slip frequency, and at the same time, the magnitude and phase of the secondary current can be controlled at high speed as necessary. The magnitude of the magnetic flux in the secondary circuit and the phase angle with respect to the armature circuit side can be quickly adjusted, and as a result, instantaneous control of power with the grid side is possible. A system consisting of a single-wound induction machine, a cycloconverter, and its control device having such a function is commonly called an AC variable speed machine, and the present invention is directed to a wound-wound induction machine and a synchronous machine of this AC variable speed machine. By directly connecting the cycloconverter and controlling the frequency converter such as the cycloconverter, the same function as the armature moving device in the case of a synchronous frequency converter can be achieved.

(Function) The difference from conventional synchronous frequency converters is that instead of the armature moving, the cycloconverter control changes the magnitude and phase of the internal induced voltage created by the magnetic flux of the rotor secondary circuit. Unlike mechanical operation, it is electrically controlled, so power can be adjusted quickly.

At the same time, the terminal voltage of the wound induction machine can also be adjusted.

(Example) Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a block diagram of an embodiment of the present invention.

In FIG. 1, 1 is a synchronous machine, 2 is a wound induction machine, and 3 is a direct connection shaft that directly connects them. As a control system of the synchronous machine 1, 4 is a voltage detection value of the terminal voltage, and 5 is an automatic voltage control device @ (AV
R) and 6 are excitation windings, and the winding voltage becomes the output of the automatic voltage controller (AVR) 5. Well, wound wire induction @2
As for the structure of the AC variable speed machine including, 7 is an AC excitation winding, and 8 is a frequency converter, which controls the magnitude, phase, and frequency of the AC excitation current flowing through the AC excitation winding 7.

9 is a frequency conversion bag [1 frequency conversion bag is a power transformer for 8]; 10 is a power detector for detecting the power output of the wound induction machine 2; 11 is a power detector 1;
0 is the output power detection signal, 12 is the target power signal (P) for power control, and 13 is the power detection signal 11 and the target power signal 12 compared, and if there is an error, the frequency converter 8 This is a power control device that controls power by 14 is a power control signal of the power control device W113. In addition, as another control means, the voltage detection signal 15 detected from the terminal of the wound induction machine 2 is compared with the target voltage signal 17 (V), and if there is an error, the voltage is controlled by the frequency converter 8. There is a equipped g16. 18 is a voltage control signal of the voltage control device 16. The frequency conversion device 8 controls the power of the wound induction machine 2 and the voltage of the terminal based on two control signals, the power control signal 14 and the voltage control signal 18. However, a wound induction machine 2 is required for these controls.
The rotation speed detection signal 20 of the resolver 19 is inputted to detect the rotation speed of the rotor, and the voltage detection signal 15 is inputted to detect the phase of the terminal voltage.

Comparing FIG. 2 and FIG. 1, it is clear that the present invention combines the synchronous machine IB and the armature moving device i! It can be seen that the wound induction machine 2, in which voltage control and power control are performed by the frequency converter 8 instead of the frequency converter 8, is a system in which the synchronous machine IA is directly connected to the shaft.

In the embodiment configured as described above, if a change in the terminal voltage or a change in power of the wound induction machine 2 occurs, that is, an error from each target value occurs during operation, the frequency converter 8 controls the power. The signal 14 and the voltage control signal 18 are input, and the frequency converter 8 uses the signals to control the magnitude of the AC excitation current flowing through the AC excitation winding 7 and the phase with respect to the terminal voltage based on the voltage detection signal 15, and at the same time adjusts the slip frequency. is calculated from the voltage detection signal 15 and the rotation speed detection signal 20, and the frequency of the AC excitation current flowing through the AC excitation winding 7 is controlled so as to follow this frequency. As a result, the magnitude and phase of the internal induced voltage created by the magnetic flux of the first rotor's secondary circuit can be controlled at high speed, so changes in the magnitude can be used to adjust the terminal voltage, and changes in the phase can be used to adjust the power. can be done quickly. Changes in power on the side of the wound induction machine 2 are transmitted to the synchronous machine 1 via the direct-coupled shaft 3, and are transmitted to the system A as changes in the power of the synchronous machine 1.

Here, if the target power signal 12 is a constant value, the power of the wound induction machine 2 is controlled to be kept constant by power control as described above, and the interchange power between system A and system B is does not change. Furthermore, if the target power signal 12 is changed by some means, the power of the wound induction machine 2 is similarly changed by power control so as to follow the target power signal 12.

〔Effect of the invention〕

As explained above, according to the embodiment, the AC excitation current flowing through the AC excitation winding is controlled at high speed by a frequency converter instead of one synchronous machine of a conventional rotary grid interconnection device. Since this method uses a rotary system, it is possible to realize a rotary grid interconnection device that can control power at high speed so as to follow a target power signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional synchronous frequency converter. 1...Synchronous machine 2...Wound induction machine 3.
... Directly connected shaft 4 ... Voltage detection value 5 ... Automatic voltage control device 6 ... Excitation winding 7 ... AC excitation winding 8 ... Frequency conversion device 9 ... Transformer
10... Power detector 11... Power detection signal
12...Target power signal 13...Power control device
14... Power control signal 15... Voltage detection signal
16... Voltage control device 17... Target voltage signal
18... Voltage control signal 19... Resolver
20... Rotation speed detection signal 101... Armature moving device agent Patent attorney Noriyuki Chika System A Figure 1 Figure 2

Claims (1)

[Claims] In a rotating system interconnection device in which a rotating machine connected to one power system and a rotating machine connected to the other power system are connected by a direct shaft, one rotating machine is a synchronous machine and the other A rotating system interconnection device characterized in that the rotating machine is a wound-type induction machine, and the AC excitation current flowing through the AC excitation winding of the wound-type induction machine is controlled at high speed by a frequency converter. .