Automation of the drive G-D mine hoist and excavators is closely related to the use of electromachine amplifiers in it - special electrical machines with a high gain and high speed. These qualities of electromachine amplifiers have determined their widespread use and contributed to the development of various control schemes built on a closed loop.However, the experience of operation and research drives G-D mine hoisting and excavators with electromachine control show that the systems with electromachine amplifiers are very complex, transients in them have unfavorable character, in general, the operation of drives is not characterized by reliability and stability.

The main drives of the excavator EKG-8 are made according to the G-D system and have a control scheme based on the electromachine and magnetic amplifiers (scheme with EMU-PMU cascade). This scheme, as tests have shown, has a number of drawbacks.At present, in connection with the transition to mass production of excavators EKG-8 there is a need to develop simpler and better automatic control schemes. Promising in this respect are control schemes of electric drives of the excavator built on the basis of magnetic amplifiers (MU). When developing such schemes, it is very important to correctly build the excitation circuit of the generator, as it largely determines the structure and parameters of the control circuit as a whole and, ultimately, the properties of the drive.

Transients in a closed single-loop system under certain assumptions can be described by a linear differential equation…

In a mine hoisting machine, the controlled object is the drive motor. The autoregulation system should provide a certain program speed of the machine per lifting cycle with proper transients in the electric drive- According to the structure, the control system of the hoisting electric drive is a scheme with feedback on the motor speed (Fig. 1). Regulator B-P in this scheme performs the functions of an adder of influences: setting program of speed change and regulating influence, transmitted by negative feedback from the output to the input of the system.

Reliability of the braking device is of particular importance in the transfer of lifting systems from manual control to automatic.All domestic lifting machines, having coiling apparatuses with a diameter of 4 m and above, are equipped with a fast-acting pneumatic braking device Novo-Kramatorskiy machine-building plant (NKMP).

As it is known, transient processes in the system under certain assumptions can be described by a linear differential equation. The order of the differential equation is determined by the number and nature of the links included in the system, since the differential equations of these links are the initial equations for the general equation of dynamics of the entire system.

The object of regulation in an electromechanical system is an electric machine - usually a motor or a generator.For automatic control and regulation of motor speed or generator voltage, closed-loop systems with negative feedback (regulating) are the most common. The main parameter of such a system, which determines its quality in steady-state modes, is the gain of the open-loop control circuit K, which is understood as the product of the gain (conversion) of all links of the control circuit. For example, for the system of electric machine control and motor speed regulation, the structural diagram of which is shown in Fig. 1, the gain of the open-loop regulation circuit is defined by the expression.