The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 2017
Filed:
May. 12, 2015
Delta Electronics (Shanghai) Co., Ltd., Shanghai, CN;
Bin Liu, Shanghai, CN;
Zheng Wang, Shanghai, CN;
Yi Zhang, Shanghai, CN;
Hong-Jian Gan, Shanghai, CN;
Jian-Ping Ying, Shanghai, CN;
DELTA ELECTRONICS (SHANGHAI) CO., LTD., Shanghai, CN;
Abstract
A variable frequency speed control system having a low voltage ride through function that includes a variable frequency drive having a rectifier, a DC bus and an inverter is provided. The variable frequency speed control system includes a voltage drop detecting module, a frequency control module, an operation mode selecting module and an inverter control module. The voltage drop detecting module generates a voltage drop coefficient according to a grid voltage and a rated grid voltage and generates an operation mode switching signal. The operation mode selecting module receives a target frequency signal and a frequency decreasing amount and generates an output frequency signal according to the operation mode switching signal. The inverter control module generates a three phase modulating signal according to the output frequency signal, which is used to control the operation of the inverter.