Starting/generating system and its control method based on two-stage matrix converter

Abstract

The invention discloses a two-stage matrix converter based starting / generating system and a control method thereof. In the system, a starter / generator is disposed on a unidirectional switch side of a converter, and a starting power source and a load are disposed on a bidirectional switch side. On hardware, only a switch needs to be arranged between the starting power source and the load to achieve switching from a starting state to a generating state; during state switching, control algorithms need not to be changed too much; the whole starting / generating system has the advantages of compact structure, efficiency and reliability, achieves starting / generating integrated operation easily, and is suitable for aviation starting / generating systems.

Description

technical field [0001] The invention relates to a novel starting / generating system based on a double-stage matrix converter and a control method thereof, belonging to the field of matrix converters and starting / generating systems. Background technique [0002] For a long time, the starting of engines in many occasions such as aircraft and vehicles requires the use of special electric starters (such as brushed DC motors) or non-electric starters (such as air turbine starters and gas turbine starters). The starter / generator technology makes the generator connected to the engine dual-purpose. When the engine is started, it works as a starter, drives the engine rotor to rotate to a certain speed, and then injects fuel to ignite, so that the engine enters a self-working state. After that, the engine drives the motor in turn, making it a generator to supply power to electrical equipment. The starter / power generation integrated technology unifies the generator and starter, elimina...

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Problems solved by technology

[0003] The four-quadrant AC-AC power converter is a key component of the AC starter / generator system. The traditional dual-PWM converter requires a larger DC bus energy storage capacitor and a heavier filter inductor, and cannot be integrated into the starter / generator. Internal, not conducive to the improvement of system performance

The first structure is aimed at the brushless DC motor, which places the motor on the bidirectional switch side of the two-stage matrix converter, and the starting power supply and load on the unidirectional switch side, such as figure 1 As shown in (a), this system is the first to combine the two-stage matrix converter and the brushless DC motor in the starting / generating system, which is especially suitable for high-speed applications, but is limited by the inherent characteristics of the two-stage matrix converter. characteristics, this structure will cause an overcurrent fault in the starting state, resulting in failure to start; the second structure is aimed at electric excitation or hybrid excitation synchronous motors, and the motor is also placed on the bidirectional switch side, such as figure 1 As shown in (b), this structure is equipped with a set of filter capacitors with switches on both sides of the converter. The system hardware structure is changed through the switch to realize the start function, and there is no requirement for the start-up time of the system. However, the introduction of the switch The converter is exposed to the risk of overvoltage, and an unnecessary overvoltage absorbing circuit is introduced. The entire system requires more capacitors and inductance components, and the hardware composition is complicated. It does not have the advantage of the compact structure of the two-stage matrix converter. When the state is switched to the power generation state, the converter needs to change the modulation algorithm, which increases the difficulty of implementing the algorithm

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