| By using new technical achievements in micro-electronic and micro-processor fields, several weak links of commutatorless motor (CLM) are researched in the following. Through analysis of materials of finite state machine (FSM), improved FSM (IFSM) is designed, which can be used as software analysis tool of small embedded system. Analysis result described by IFSM can be easily transferred to N-S block diagram which is widely used as software design tool and program based on block diagram can ensure structure software. By using IFSM, both whole process time-domain simulation model and real device of CLM are developed. Transfer function model of CLM is built and regulator parameters of double-closed loop adjustable speed (ASD) system of CLM are calculated by using engineering design method. Then based on power system toolbox provided with simulink software, main circuit model of CLM is built and by using matlab language, control software is programmed. Whole process time-domain simulation model is developed by combination of main circuit model and control software. Low speed current-interruption running characteristics and terminal voltages of stators of CLM are analyzed based on the simulation model. In order to simplify the complex installation and adjustment process of phase-controlled converter (PCC) of CLM, PCC principle is re-analyzed. Based on connection-symbol fundamentals of transformer, internal relations of different voltage-levels of power network are revealed and then phase relation between voltage and current of inductive load is analyzed. It can be concluded that every phase of low voltage AC source can be selected as synchronous voltage, such as power source of control circuit. Phase sequence and phase of main circuit can be calculated by software. At last phase sequence and phase auto-recognition algorithm is formed, which is used to improve traditional PCC software. When this method is used, high voltage PT can be omitted and adjustment process of PCC can be simplified. Because CLM is adjusted from standstill to rated revolution, three-phase terminal-voltages amplitude and frequency vary greatly and their waves have serious distortion. Whole process electric rotor position detector has been widely researched, but it is not well solved. In the current, mechanical rotor position sensor is used during low speed period of CLM and changed to electric rotor position detector in high speed period. By using a series specially designed methods, the problem of electric rotor position detection from start to rated speed of CLM is solved, which only use three-phase stator's voltage as measurement variables. This method has no relation with poles of motor and can make CLM start under closed-loop control. Good results are gained through experiments on a test motor. Based on above researches and newest achievements of micro-processor and micro-electronics fields, advanced control system of CLM is developed. For many new types high-speed ICs are used, many anti-disturbance measures are designed to improve reliability. The control system is used in two SMs for test run. One is used to control a 1kV, 400kW and 4-pair poles SM in laboratory, which drives a DC generator; the other is used to control a 6kV, 300kW and 7-pair poles SM in an air compressor shop, which drives an air compressor. Test run shows that control system has good performance. A set of medium-voltage thyristor-valve system is designed and it's technical characteristics include: independent triggering power is designed because inverter triggering power source can not gain from damped capacitor circuit when CLM is operating in low speed; thyristor fault detection circuit is designed based on measure of inverse voltage of thyristor and valve fault detection system is designed to check all thyristors in turn; triggering pulses do not adopt code pattern, which are directly transmitted to triggering circuit of every thyristor through optical fiber in order to simplify design and increase response speed; air cooling system is adopted. Thyristor valve system is used in a 6kV CLM introduced in the former. Through change of thyristor's number and parameters, this device can be used in the range of 6kV-10kV and 200kW-2000kW. To sum up, several achievements are made in the following aspects: engineering method of development of small embedded system, whole process time-domain simulation model of CLM, phase sequence and phase auto-recognition algorithm of phase-controlled rectifier, achievement of whole process electric rotor position detector, development of control system for high voltage CLM, development of medium-voltage thyristor valve system.
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