Brake device for AC generator

Patent metadata

Field	Value
Publication number	US-10826419-B2
Application number	US-201716088027-A
Country	US
Kind code	B2
Filing date	Mar 15, 2017
Priority date	Mar 22, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A brake device for an AC generator, whose speed can be flexibly controlled, and can function properly even when functions of the control unit are lost.

First claim

What is claimed is:

1. A brake device for an AC generator comprising:
a triac including:
a first terminal electrically connected to a first transmission line of the AC generator,
a second terminal electrically connected to a second transmission line of the AC generator, and
a gate;

a first switching unit electrically connected between the gate and the second terminal and configured to receive power from the AC generator;
a second switching unit configured to switch the first switching unit between an ON-enabled state and an off-state;
wherein, when the first switching unit is in the ON-enabled state and the absolute value of a line-to-line voltage between the first transmission line and the second transmission line exceeds a selected value, the first switching unit turns on using the line-to-line voltage as a driving power source and triggers a short-circuit current flow in between the transmission lines through the triac;
wherein the first switching unit is in the ON-enabled state when the second switching unit is off, and the first switching unit is in the off-state when the second switching unit is on;
wherein the second switching unit and a control unit configured to control the switching of the second switching unit are powered by a common power source different than the AC generator; and
wherein the second switching unit is configured to automatically switch off when the common power source is lost.

2. The brake device according to claim 1 , wherein the first switching unit comprises a first switching element and a second switching element each connected to a control terminal;
wherein a first switch terminal of the first switching element is connected to the gate, and a second switch terminal of the second switching element is connected to the second terminal;
wherein a third switch terminal of the first switching element and a fourth switch terminal of the second switching element are connected to a first common point;
wherein a first control terminal of the first switching element and second control terminal of the second switching elements are connected to a second common point; and
wherein a fifth switch terminal of the second switching unit is connected to the first common point and a sixth switch terminal of the second switching unit is connected to the second common point.

3. The brake device according to claim 1 , further comprising:
a rotational frequency detection unit configured to measure the rotational frequency of the AC generator;
wherein switching of the second switching unit is based on a selected rotational frequency measured by the rotational frequency detection unit.

4. The brake device according to claim 1 , wherein the AC generator outputs a three-phase AC.

5. The brake device according to claim 1 , wherein the AC generator comprises a wind-power generation device.

6. The brake device according to claim 1 , wherein the AC generator comprises a permanent magnet synchronous generator.

7. A brake device for an AC generator comprising:
a triac including:
a first terminal electrically connected to a first transmission line of the AC generator,
a second terminal electrically connected to a second transmission line of the AC generator, and
a gate; and

a first switching unit electrically connected between the gate and the second terminal and configured to receive power from the AC generator;
wherein, when a voltage between the first transmission line and the second transmission line exceeds a selected value, the first switching unit triggers a short-circuit current flow between the first and second transmission lines.

8. The brake device according to claim 7 , further comprising:
a second switching unit configured to disable the first switching unit when the second switching unit is on.

9. The brake device according to claim 8 , wherein the second switching unit is powered by a secondary power source and configured to automatically switch off when the secondary power source is lost.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Haneda Masaji

Classifications

• F03D9/257

  the wind motor being part of a wind farm · CPC title

• H02P15/00

  Arrangements for controlling dynamo-electric brakes or clutches (vector control H02P21/00) · CPC title

• F03D7/028

  controlling wind motor output power · CPC title

• H02P9/006 Primary

  Means for protecting the generator by using control (control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10) · CPC title

• F05B2220/7068

  equipped with permanent magnets · CPC title