JPH0471332A - Rotary system interlocking device - Google Patents

Abstract

PURPOSE:To rapidly control delivery and reception of power between systems in response to setting of a target power signal by individually rapidly controlling an AC exciting current flowing to an AC exciting winding with two rotary machines as wound-rotor type induction machines. CONSTITUTION:A wound-rotor type induction machines 1A, 1B are coupled directly by a direct-coupling shaft 2. Frequency converters 4A, 4B control amplitudes, phases, frequencies of AC exciting currents flowing to AC exciting windings 3A, 3B. If an error occurs from a target value at terminal voltage or power of the machines 1A, 1B, power control signals 10A, 10B and voltage control signals 14A, 14B are respectively input to the converters 4A, 4B, which are controlled in amplitudes of AC exciting currents flowing to the windings 3A, 3B and phases to a terminal voltage based on voltage detection signals 11A, 11B. Thus, the amplitude and phase of an inner induced voltage formed of a magnetic flux of a secondary circuit of a rotor can be controlled at a high speed.

Description

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

(Prior Art) Conventionally, as a rotary interconnection device, as shown in FIG.
There is a so-called electric ratio frequency conversion type synchronous frequency converter in which the two are directly connected with each other, and the ratio of the number of poles of both is selected to be equal to the ratio of their respective frequencies. This converter is equipped with an armature moving device 105 that can move one of the armatures in the circumferential direction to adjust the load angle in order to control the passing power.

Since this armature moving device 105 operates mechanically, it is originally impossible to control passing power at high speed, and is not useful when emergency power interchange is required in the power system.

In addition, 103A and 103B in the figure are automatic voltage regulators (A
VR), 104A, and 104B 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 rotary type interconnection device could also perform high-speed control of passing power when emergency accommodation from another power system is required due to problems with system stability or frequency fluctuations.

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

[Structure of the invention] (Means for solving the problem) Volume! An induction machine uses a frequency conversion device such as a cycloconverter to cause a secondary current having a slip frequency equal to the difference between the power system frequency and the rotor frequency to flow through its secondary winding.
By controlling the magnitude and phase, 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 wound induction machine, a cycloconverter, and its control device that has such functions is commonly called
Although it is called an AC variable speed machine, the present invention directly connects the shafts of two wound induction machines of this AC variable speed machine, and separately controls their frequency converters such as cycloconverters, thereby achieving a synchronous synchronous frequency. Not only can it quickly achieve the same passing power adjustment function as an armature moving device in the case of a converter, but it can also store electric energy instead of the inertial energy of a rotating machine, contributing to system operation.

(Function) The difference from the conventional mechanically operated synchronous frequency converter is that instead of the armature moving, the cycloconverter controls the magnitude of the internal induced voltage created by the magnetic flux of the rotor secondary circuit. Since the phase changes, electrical power can be adjusted individually at high speed for each rotating machine because it is electrically controlled. 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, AC variable speed machines on the side of system A are distinguished by adding A after the number, and AC variable speed machines on the side of system B are distinguished by adding B after the number. The A or B added after the number is simply a symbol to distinguish between the two AC variable speed machines, and those with the same number mean the same equipment or physical quantity.

Here, IA and IB are wound-type induction machines, and 2 is a direct connection shaft that directly connects the wound-type induction machines IA and IB. Also, 3A3
B is an AC excitation winding, 4A and 4B are frequency converters,
The magnitude, phase, and frequency of the AC excitation current flowing through the AC excitation windings 3A and 3B are controlled. 5A, 5B
are power transformers for the frequency converters 4A and 4B, respectively. 8A and 6B are power detectors for detecting the power output of the wound induction machines IA and IB, 7A and 7B are the power detection signals of the outputs of the same power detectors BA and 13B, 8
A, 8B is the target power signal for power control, and 9
A and 9B are power control devices that compare the power detection signals 7A and 7B with the target power signals 8A and 8B, and if there is an error, control the power using the frequency conversion devices 4A and 4B. 10A10B is a power control signal for the power control devices 9A and 9B.

Further, 12A and 12B are referred to as voltage control devices, and voltage detection signals 11A and IIB detected from the terminals of the wound induction machines IA and IB and target voltage signals 13A,
13B, and if there is an error, the voltage is controlled by the frequency converters 4A and 413. 14A.

14B is a voltage control signal of the voltage control devices 12A and 12B. Frequency converters 4A and 4B provide power control signal 10A.

The power and terminal voltage of the wound induction machines IA and IB are controlled based on the two control signals 1013 and voltage control signals 14A and 1.4B, but the wound induction machine IA is necessary for these controls. , IB are input to the rotation speed detection signals 1BA and 1BB of the resolvers 15A and 15B in order to detect the rotation speed of the rotors, and voltage detection signals 11A and IIB are input in order to detect the phase of the terminal voltage.

Comparing the conventional example shown in FIG. 2 with the present invention shown in FIG. 1, the present invention is a system consisting of an armature moving device 105 in which a synchronous machine 101A and a synchronous machine 101B are directly connected to each other by shafts and installed on the side of the synchronous machine 101B. Instead, it can be seen that the system is a system in which two wound induction machines IA and IB are directly connected to each other, each of which is subjected to voltage control and power control by frequency converters 4A and 4B, respectively.

In the embodiment configured as described above, the wound induction machine IA
, IB terminal voltage change or power change, that is, if an error from each target value occurs during operation, a power control signal 10 is sent to the frequency converter 4Δ2413.
A, IOB and voltage control signals 14A, 14B are input, and the frequency converters 4A, 4B use these signals to determine the magnitude and phase of the AC excitation current flowing through the AC excitation winding 3Δ, 813 and the phase with respect to the terminal voltage using the voltage detection signal 11A,
At the same time, the slip frequency is controlled based on the voltage detection signal 11A, 11. B and rotation speed detection signal 1
6A, calculated from IEiB, always AC excitation winding 3
A.

The frequency of the AC excitation current flowing through 3B is controlled to follow this slip frequency. As a result, the magnitude and phase of the internal induced voltage created by the magnetic flux of the rotor secondary circuit can be controlled at high speed, so changes in magnitude can be used to adjust terminal voltage, and changes in phase can be used to adjust power. can be done quickly. Here, if the target power signals 8A, 8B
If is a constant value, the power of the wound induction machines LA and 1B is controlled to be kept constant by power control as described above.

In the grid interconnector configured as shown in FIG. 1, transfer of power from grid A to grid B can be realized by controlling as follows. That is, assuming that the polarity of the target power signals 8A and 8B is positive in the direction in which they are sent from their respective wound induction machines to the grid, if the amount of power passing from grid A to grid B is, for example, Pc, the target power signal 8A and 8B are set as follows.

Target power signal 8A P*= -Pc Target power signal 88 P*= Pc If the following settings are made, power will be received from both grid A and grid B, and as a result, this grid interconnector will Due to its inertia, electric energy can be absorbed as rotational energy.

Target power signal 8A P*--Pc Target power signal 88P*--Pc Here, if the polarity of both target power signals is set to +, power energy can be released in the opposite direction.

[Effects of the Invention] As explained above, according to the embodiment, instead of two synchronous machines in a conventional rotary grid interconnection device, both rotary machines are wound induction machines, and each frequency converter is used as a wound type induction machine. Since the AC excitation current flowing through the AC excitation winding of the winding induction machine is individually controlled at high speed, power transfer between systems can be performed at high speed according to the setting of each target power signal. A rotary grid interconnection device that can be controlled can be realized.

[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. LA, IB...Wound induction machine 2...Directly coupled shaft 3A, 3B...AC excitation winding 4A, 4B...Frequency converter [iA, 8B...Power detector 9A, 9B... - Power control devices 12A, 12B... Voltage control devices 15A, 1
5B...Resolver agent Patent attorney Noriyuki Chika

Claims (1)

[Claims] In a rotating system interconnection device in which a rotating machine and another rotating machine are connected by a direct shaft, both rotating machines are wound type induction machines,
The invention is characterized in that the AC excitation current flowing through the AC excitation windings of each wound induction machine is individually controlled at high speed by a frequency conversion device installed for each wound induction machine. Rotating grid connection device.