Control device and method for SCR detection as well as control device and method for power supply changeover

Abstract

The invention discloses a control device and a method for SCR detection, as well as a control device and a method for power conversion. The detection control is carried out by taking GK interelectrode voltage UGK as the judgement basis of judging whether the SCR is switched on, namely judging the current condition of a SCR by detecting the UGK. The utilization of the control devices and the methods of the invention have fast judgement process and high precision, furthermore, the circuit complexity is not increased, and the cost is low, thereby adapting to the detection control of various SCR parts.

Description

technical field [0001] The invention relates to a detection and control technology using a silicon controlled rectifier (SCR) as a switching device. Background technique [0002] The existing detection and control technology using a silicon controlled rectifier (SCR) as a switching device has a very wide range of applications, such as uninterruptible power supply control systems and the like. The switching device used is SCR, which is a semi-controlled device and can work reliably under high voltage and high current. However, there are two disadvantages: one is that the SCR is turned off uncontrolled; the other is that the maintenance current of the SCR is very small when it is turned on, usually within two to three hundred milliamperes, and the operating current is extremely large, ranging from tens of amps to several Baian, the current current detection solutions (such as Hall elements, current transformers) have problems of high cost or large volume. Taking the situatio...

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Problems solved by technology

However, there are two disadvantages: one is that the SCR is turned off uncontrolled; the other is that the maintenance current of the SCR is very small when it is turned on, usually within two to three hundred milliamperes, and the operating current is extremely large, ranging from tens of amps to several Baian, the current current detection scheme (such as Hall element, current transformer) has the problem of high cost or large volume

In addition, the A and K poles of the SCR are connected to the power supply terminal and the load terminal. When the SCR is turned off, due to the voltage fluctuation between the power supply terminal and the load terminal, the voltage between AK may also be within the conduction range of 0.5~4V, and it is judged to be in conduction. state, leading to misjudgment

Therefore, the accuracy and reliability of the program control provided in this case are not good

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