Two-way four-quadrant frequency converter

Abstract

The invention discloses a two-way four-quadrant frequency converter, and belongs to the technical field of low power wind power generation. The two-way four-quadrant frequency converter comprises a switching power supply, a driving protective circuit, a program upgrading interface circuit, a coder interface circuit, a DSP (digital signal processor) controller, a first drive circuit, a second drive circuit, a signal acquisition circuit, an alternating-current input reactor, a first circuit breaker, a grid-side frequency converter, a rapid overflowing fuse protector, a current foldback circuit, a motor-side frequency converter and an alternating-current output reactor. According to the invention, the two-way four-quadrant frequency converter avoids the situation that two controllers can not simultaneously achieve coordination control so as to cause direct current bus voltage fluctuation under the occasion of load power and power-supply voltage jump and the like, and the direct current bus voltage after control is more stable; and the two-way four-quadrant frequency converter solves the defects that the electricity is taken from a direct current bus, the integration level of the frequency converter is improved, the structure of the frequency converter is simplified, and the safe operation of the frequency converter is farthest ensured.

Description

technical field [0001] The invention belongs to the technical field of low-power wind power generation, and in particular relates to a bidirectional four-quadrant frequency converter. Background technique [0002] At present, in the generator control experiments of wind turbines, it is generally carried out on the high-power prototype machine. Due to the complexity of the unit system, the pitch system, yaw untwisting system, hydraulic braking system, frequency conversion system, data acquisition and communication system and other links There are many and interact with each other, which brings great inconvenience to the independent study of the control problems of the main system, and because the unit has high safety requirements, large power capacity, and high experimental cost, it brings great inconvenience to the experimental work. difficulty. [0003] In the traditional motor speed control experiments, two-quadrant general-purpose frequency converters are widely used to ...

AI Technical Summary

Problems solved by technology

This transformation method can realize the function of bidirectional four-quadrant inverter, but there are also the following problems: since the auxiliary power input circuit inside the general inverter is mostly integrated with the uncontrollable rectification circuit, simply leaving the uncontrollable rectification part vacant will cause problems. As a result, some auxiliary power circuits cannot work normally, which in turn causes the DC bus voltage and current detection circuit inside the inverter and the IGBT temperature detection circuit to fail to work, causing the inverter to report DC bus undervoltage and other faults and fail to start.

However, for frequency converters that have already been put into production or are not provided by the same equipment manufacturer, it is often impossible to jump-connect the internal circuit of the frequency converter. This method has great limitations.

At the same time, the circuit modification without the equipment manufacturer will bring difficulties to the maintenance and repair of the inverter.

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