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Secondary magnetic excitation generator-motor device

An electric device, sub-excitation technology, applied in the generator control circuit, controlling the generator through the change of the magnetic field, controlling the generator, etc., to achieve the effect of improving the torque variation and realizing stable operation

Pending Publication Date: 2021-12-21
HITACHI MITSUBISHI HYDRO +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

According to this method, the current degree of freedom of the excitation circuit is reduced from 2 to 1 in the normal state, so there is a problem that it is difficult to return to the current degree of freedom 2 stably and quickly, and return to normal control.

Method used

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  • Secondary magnetic excitation generator-motor device
  • Secondary magnetic excitation generator-motor device
  • Secondary magnetic excitation generator-motor device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] use figure 1 The structure of the device according to Embodiment 1 of the present invention will be described.

[0055] The three-phase AC system 1 and the stator-side armature winding 5 of the winding-type induction motor are connected via the main transformer 2 , the phase reversing circuit breaker ( 89GM ) 3 , and the synchronous circuit breaker ( 52G ) 4 . The rotor-side field winding 6 is connected to the AC side of a 3-level NPC power converter 7 . A positive side DC capacitor (CP) 8 and a first DC output terminal (VDC1) of a DC voltage source 71 are connected in parallel between the DC side positive terminal and the neutral point terminal of the 3-level NPC power converter 7 .

[0056] On the other hand, a negative side DC capacitor (CN) 12 and a second DC output terminal (VDC2) of the DC voltage source 71 are connected in parallel between the neutral point terminal and the DC side negative terminal of the 3-level NPC power converter 7 .

[0057] The AC end o...

Embodiment 2

[0087] use figure 2 The structure of the device according to Embodiment 2 of the present invention will be described.

[0088] Between the DC side positive terminal and the neutral point terminal of the 3-level NPC power converter 7, a positive side DC capacitor (CP) 8 and a DC terminal of the first 2-level power converter 9 are connected in parallel. The AC end of the flat power converter 9 is connected to a first excitation transformer 11 via a first harmonic suppression filter 10 .

[0089] On the other hand, between the neutral point terminal of the 3-level NPC power converter 7 and the negative terminal of the DC side, a negative-side DC capacitor (CN) 12 and a DC terminal of the second 2-level power converter 13 are connected in parallel, The AC end of the second two-level power converter 13 is connected to a second excitation transformer 15 via a second harmonic suppression filter 14 .

[0090] The AC system side ends of the first excitation transformer 11 and the se...

Embodiment 3

[0098] use figure 2 The structure of the device according to Embodiment 3 of the present invention will be described.

[0099] The bypass circuit 48 is provided between the field current instrumentation converter 34 and the terminal of the rotor side field winding 6 of the winding type induction motor. The bypass circuit 48 may also be composed of a power semiconductor element, but a vacuum circuit breaker with remarkable technical progress such as a guaranteed number of operations of 150k times may be used as in the present embodiment. This bypass circuit is closed in response to an 86E command from the operation mode switching circuit 41 . In addition, according to the GB instruction, the gate of the self-arc-extinguishing element of the 3-level NPC power converter 7 is blocked by the pulse generating circuits 45, 46, 47 to stop the operation.

[0100] Image 6 A circuit that outputs an operation command (command 86E) to the bypass circuit 48 is shown.

[0101] The maxi...

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PUM

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Abstract

A secondary magnetic excitation generator-motor device, in which a first firing pulse command is input into a three-level NPC electric power converter such that a magnetic excitation current detected value matches a magnetic excitation current command value, is provided with a function for identifying a first phase, a second phase, and a third phase in decreasing order of absolute current value, and a pulse command unit which fixes a firing pulse of a P-group or an N-group of the first phase, in a direction charging first and second direct current capacitors, to an on-side, and fixes the opposite side to an off-side, fixes a firing pulse of a P-group of the second phase to the same side as the N-group of the first phase, and fixes a firing pulse of an N-group of the second phase to the same side as the P-group of the first phase, fixes a firing pulse of a first group of the third phase to ON, and a firing pulse of a second group of the third phase to OFF, and outputs the same as a second firing pulse command, wherein a pulse switching unit which outputs the firing pulse commands to the three-level NPC electric power converter switches to the second firing pulse command if the absolute current value exceeds an overcurrent set level 1, and switches to the first firing pulse command if the absolute current value of all three phases is at most equal to an overcurrent set level 2.

Description

technical field [0001] The present invention relates to a secondary excitation power generator using a secondary excitation power converter. Background technique [0002] The AC excitation generator motor using the power converter for secondary excitation can control the reactive power output in the same way as the conventional fixed-speed synchronous machine, and can realize high-speed torque control or high-speed active power within the rotation speed range around the synchronous speed control. Therefore, compared with conventional fixed-speed generator motors, there is an advantage that prime movers such as pump-turbine systems and wind power generation systems can be optimally operated under wider operating conditions. In addition, there is an advantage of contributing to frequency stabilization of the power system by temporarily releasing and absorbing the flywheel energy of the rotating part into the power system. [0003] On the other hand, although the power conver...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02P9/10
CPCH02P9/007H02P27/14H02M7/487H02M1/325H02M7/5395H02K21/04H02P9/38
Inventor 阪东明川添裕成菊池辉
Owner HITACHI MITSUBISHI HYDRO