Low-cost variable pitch system

Abstract

The invention discloses a low-cost variable pitch system which comprises a programmable logic controller (PLC) module, an absolute value encoder and a variable pitch driver, wherein the variable pitch driver is provided with a digital signal processor (DSP). An output end of the absolute value encoder is communicated with an input end of the DSP by a small scale integration (SSI) port, and an output end of the DSP is communicated with an input end of the PLC module, through a communication mode. An existing hardware condition is used so as to save multiple PLC modules, and reduce the number of lines between equipment cabinet plugs. A communication module on the PLC module only needs increasing, so that working load of the PLC module is reduced, and cost of a variable pitch system is reduced.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a low-cost pitch control system. Background technique [0002] The main function of the pitch system is to control the angle of blade rotation according to the change of wind speed and ensure the constant power output of the wind turbine. Axis control cabinet for the driver, 3 battery cabinets, 3 motors with integrated thermistor, absolute encoder and braking device, 3 redundant absolute encoders, 6 limit switches. The absolute value encoder signal of the motor is transmitted to the PLC module through the synchronous serial interface. The PLC module needs three EL5001 encoder modules to receive this signal, so as to obtain the actual position signal of the motor; the pitch driver passes the tachometer generator installed on the motor or The incremental encoder compounded on the absolute encoder obtains the actual speed of the motor to control the speed of the motor; the PLC ...

AI Technical Summary

Problems solved by technology

The absolute value encoder signal of the motor is transmitted to the PLC module through the synchronous serial interface. The PLC module needs three EL5001 encoder modules to receive this signal, so as to obtain the actual position signal of the motor; the pitch driver passes the tachometer generator installed on the motor or The incremental encoder compounded on the absolute encoder obtains the actual speed of the motor to control the speed of the motor; the PLC module outputs an analog voltage signal to the three pitch drivers through an EL4034 analog output module as a speed reference ;The PLC module also needs two EL3112 modules to detect the motor current; and several EL3204 modules to detect the temperature; this series of modules not only increases the complexity of the entire system, but also makes the PLC module operate under high load, and also increases the difficulty of maintenance , leading to higher hardware and labor costs

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