Fault Analysis and Solutions of Generator Set Rotating Rectifier

The main function of the 500kw rotating rectifier of the generator set is to convert the three-phase AC excitation current output by the AC exciter armature into DC current through the diodes on the rectifier, and provide the excitation current with the rotor winding as the power source. It is this application that enables the AC synchronous generator to get rid of the constraint of the brush and no longer need frequent maintenance and replacement of parts, so it is widely used.

Some generators, in order to have a more compact structure, install the rotating rectifier on the inside of the rear cover and directly fix it to the bolt extending from the armature core of the excitation machine. For the convenience of installation and maintenance, some rotating rectifiers are installed on the outside of the AC exciter and fixed to the shaft with screws. The rotating rectifier circuit is divided into two types: three-phase bridge rectifier and three-phase half wave circuit. If a three-phase bridge rectifier circuit is used, in order to facilitate installation and reduce the connection lines of rectifier components, and improve the reliability of generator operation, two types of tubes, forward and reverse, need to be used.

If the rotating rectifier is damaged, failure to detect and eliminate the fault in time will lead to burnout of the AC exciter armature winding and short circuit of the circuit, and the generator will be forced to shut down. Then what are its fault causes and solutions? The specific points are as follows:

1.Causes of generator rotating rectifier failure

The silicon rectifier diode of the rotating rectifier is damaged due to overvoltage or overcurrent. When installing the silicon rectifier element of the rotating rectifier, the torque is too large, resulting in shell deformation and internal silicon chip damage. The load power factor is low, making the excitation current exceed the rated current of the silicon rectifier element for a long time and causing damage.

2.Fault treatment method of generator set rotating rectifier

Use rotating silicon elements according to the current level specified in the drawings. If there is no drawing information at hand, the voltage level of the rotating silicon element can be reasonably selected according to the excitation current value of the main generator and relying on standard specifications. The reverse peak voltage of the rotating element is 10-15 times the excitation voltage. Tighten the nut of the rotating silicon element with appropriate torque.

Founded in 1974, Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. Generation Equipment Co., Ltd. is a professional manufacturer of diesel engines, generators and generator sets, and one of the earliest manufacturers of diesel engines, generators and generator sets in China. Since 1992, the company has been a qualified generator set manufacturer inspected by the National Internal Combustion Engine Generator Set Quality Supervision and Inspection Center. Over the years, the company has carried out extensive cooperation with Shanghai Diesel, Weichai, Sweden Volvo, Sino US joint venture Chongqing Cummins, American Qianglu and other companies, and has become a (OEM) supporting factory and technical center. It has 64 sales service departments nationwide, providing users with design, supply, commissioning and maintenance services at any time. Dingbo quality is worth depending on. If you want get more information, please feel free to send email to [email protected] we will pay highly attention on your question.