A High Dynamic and High Response Control Method of Solenoid Valve Based on Voltage Pulse Width Modulation Technology

Abstract

The invention discloses a high dynamic high frequency response control method of an electromagnetic valve based on voltage pulse width modulation technology. The invention divides the single working cycle of the solenoid valve into a preload excitation stage, a preload maintenance stage, an opening stage, a reverse excitation stage, an opening maintenance stage, a closing stage, and a closing maintenance stage. The present invention adopts a single voltage source. In the preloading stage, the voltage source modulated by a high-frequency square wave signal with a duty ratio of 100% is firstly used for excitation. The current rising rate is larger, and the current will rise to the preloading current state faster , so that the time-consuming preload excitation phase is shorter; then the current is maintained at the preload current state. In the reverse excitation stage, the method uses a voltage source modulated by a high-frequency square wave signal with a duty ratio of -100% to quickly reduce the current to the maintenance current; the present invention not only reduces the average current in the working cycle, The electromagnetic energy consumption is reduced, and the electromagnetic valve can adapt to better opening and closing conditions.

Description

technical field [0001] The invention relates to the field of solenoid valve control, in particular to a high-dynamic and high-response control method for solenoid valves based on voltage pulse width modulation technology. Background technique [0002] In the solenoid valve, the number of ampere turns and the working air gap have the greatest influence on the electromagnetic force of the electromagnet. Ampere-turns is the product of the number of turns of the coil and the current in the single-turn coil. When the magnetic flux is not saturated, the greater the current, the greater the electromagnetic force; the smaller the working air gap, the greater the electromagnetic force. Since the solenoid valve is often opened when the working air gap in the electromagnet is the largest, and when it is closed is often the time when the working air gap in the electromagnet is the smallest, so the opening current is larger than the closing current. [0003] In the field of high-freque...

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Problems solved by technology

[0004] However, this control method has some shortcomings

First of all, multiple voltage sources complicate the working conditions of the system and cause large errors

Secondly, the switching time of each segment voltage in this control method is determined according to the relationship between the actual current value and the theoretical current value in the system circuit, which will cause a problem: in the high-speed solenoid valve, due to the dynamic characteristics of the solenoid valve Weak, the current dynamic characteristics of the electromagnet are better, this method will cause the voltage source to be switched when the solenoid valve spool is in motion, thereby reducing the dynamic characteristics of the solenoid valve when it is opened and closed

In the closing stage of the solenoid valve, the current has dropped below the closing current, while the solenoid spool is still in the state of slowly recovering closing motion. At this time, if the reverse voltage source is switched to a zero voltage source, it will decrease. The dynamic characteristics of its closing phase

Moreover, the control method of multi-voltage sources is easy to cause major accidents such as short circuit during power switching

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