Reactive power overexcitation regulation technology for synchronous generator

Patent metadata

Field	Value
Publication number	US-10535997-B2
Application number	US-201816469607-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Mar 7, 2017
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value of the reactive power as the goal value of the reactive power regulation to maintain the output reactive power of the generator equal to the goal value. The present invention can protect the safety of the generator, and is beneficial to support the grid voltage to improve the stability of the power system performance.

First claim

What is claimed is:

1. A novel reactive power overexcitation regulation technology for synchronous generator, wherein, comprising:
measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator;
calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating of the generator, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid;
comparing the calculated actual stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator;
using the larger value between the allowable upper limit value of the reactive power and the allowable value of the reactive power of the minimum stator current as the goal value of the reactive power regulation to maintain the output reactive power of the generator equal to the goal value.

2. The novel reactive power overexcitation regulation technology for synchronous generator according to claim 1 , wherein the goal value of the reactive power regulation is calculated as:

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Assignees

• Nr Electric Co Ltd
• Nr Engineering Co Ltd

Inventors

• Wu Long
• Liu Weiqun
• Shi Xiangjian

Classifications

• H02P9/105 Primary

  for increasing the stability · CPC title

• H02P2103/20

  of the synchronous type · CPC title

• H02J3/16 Primary

  by adjustment of reactive power · CPC title

• H02P29/60

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• H02P9/006

  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