SIMULATION OF A CLOSED SYSTEM OF A DC ELECTRIC DRIVE WITH A WIDTH-PULSE CONVERTER

This article investigates the regulation of the angular speed of an electric drive (ED) with a pulse-width converter (PWC) and a direct current motor (DC motor) of independent excitation (NV) when controlled in a closed-loop system. A proportional-integral (PI) -regulator was used as a regulator of the angular velocity. To analyze the processes in the closed-loop SHIP-DPT system, the methods of simulation are used. The principle of operation of an electric drive with control from a PWM is described. Developed and modeled EP circuits with PWM in the Matlab environment using blocks from the Simulink / SimPowerSystem library. A model block has been modeled that calculates the static and dynamic power losses of the PWP IGBT. To calculate the static and dynamic losses, the method of approximating the loss graphs was used. The obtained mathematical dependences describe quite accurately the graphs of the power losses of the IGBT transistor. It is shown that when using a PI-controller, the angular speed of the electric drive is set according to a given speed reference signal.

SYNTHESIS OF CORRECTION LINKS USING A CONTINUOUS MODEL OF A PULSE CONVERTER

This article discusses the synthesis of correction links for pulse converters using a continuous model.

Improvement of passenger car power supply

A significant part of the fleet of passenger cars in operation on Russian railways are equipped with an autonomous power supply system, in which the main source of energy is an undercar generator, which is rotated from the axle of a wheelset. The disadvantage of such a system is the limitation of the speed range in which it is possible to power consumers of electric power of a passenger car from the main source: as a rule, the lower limit of this range is 35 km/h. The article proposes a variant of a technical solution that will expand the speed range of using the undercar generator by lowering the lower limit to 25 km/h: it is proposed to provide self-excitation of the undercar generator through an inverting-type DC voltage pulse converter. The parameters of the elements of the pulse converter circuit and the possibility of expanding the boundaries of the high-speed range of operation of the EGV.08.1U1 undercar generator are estimated.

Power supply for a CIP position for bearings

Objective: Two possible options for power sources are considered: a controlled three-phase bridge rectifi er circuit with a step-down transformer and a pulse converter receiving power from the network through an uncontrolled three-phase bridge rectifi er to drive the wheel-motor units of electric locomotives and electric trains into rotation with the required frequency at the position of CIP bearing diagnostics. In both cases, it is assumed that the power supplies receive electricity from the 380/220 V, 50 Hz network. The power source is loaded with traction motors of the ER2R, ER2T, ET2, ET2M electric trains and the VL-10 electric locomotive. Methods: Mathematical modeling is used in the MatLab/Simulink environment for analytical calculations. Results: The currents and voltages of the load were determined, based on the calculations, the control angles and power factors of the rectifi er with a step-down transformer, the duty cycle of the pulse converter. Practical importance: A variant of an energy-effi cient power supply is proposed, including an uncontrolled rectifi er and a pulse converter.

Optimization of control systems for suburban trains

Objective: The use of pulse conversion of electricity on direct-current traction rolling stock is discussed. Methods: A variant of the system for regulating the operating modes of traction motors of suburban electric trains using a pulse converter based on insulated gate bipolar transistors is described. (IGBT). Results: The proposed impulse control system is presented as a possible option for the modernization of the applied control systems, which makes it possible to improve the traction and energy indicators of suburban electric trains. The advantages of pulse converters based on IGBTs are shown in comparison with converters based on one- and two-operation thyristors. A simplifi ed electrical diagram of the power circuit of a motor car with a pulse converter is presented, a description of the operation of the power circuit in the traction mode and in the modes of rheostatic and regenerative braking is given. Practical importance: The presented results of the technical and economic comparison of the control systems of the ED4M electric train with a Современные технологии – транспорту 505 ISSN 1815-588Х. Известия ПГУПС 2021/4 contactor-rheostat control system and an electric train with regulation of the operating modes of traction electric motors by a pulse converter based on IGBT prove the best energy effi ciency of an electric train equipped with a pulse control system

ENERGY SAVING TECHNOLOGIES IN THE IMPLEMENTATION OF CATHODIC PROTECTION OF PIPELINES AND TANKS

The data on the introduction of new energy-saving technologies of cathodic protection – the installation of magnetite ground electrodes, the use of new activators based on coke breeze, a pulse converter for automatic control of cathodic protection objects are considered. Practical results show that the use of magnetite anodes allows maintaining a high permissible current density, therefore, it is suitable for widespread use in various soils and seawater. The rate of dissolution of magnetite is 0.02 kg / (A • year). Magnetite anodes are also successfully used for the repair of GAZ wells (deep earthing conductors made of metal pipes). To perform this type of work, a typical project has been developed, which allows restoring the operability of deep anode grounding with minimal costs and without the use of expensive drilling operations. The use of activated coke breeze significantly reduces the transition resistance of the anode grounding. It has been practically proven that when using a coke-mineral activator, the transition resistance is significantly reduced due to an increase in the electrical conductivity of the filler at the anode space, the geometric dimensions and current of the diverting object increase, and the transition resistance of the anode - ground is stabilized. LLC "Elmet" has developed a pulse converter of automatic control IPAU designed to convert alternating current into rectified direct current with the possibility of automatic adjustments in several parameters. The basis of the converters is a high-frequency transistor inverter, developed on the basis of the latest achievements in power electronics. The use of stations of the IPAU type with telemetry allows to reduce labor costs for their maintenance in accordance with clause R.6.1 DSTU B V.2.5-29: 2006 Gas supply system. Underground steel gas pipelines and p. 8.9 of DSTU 4219: 2003 Steel main pipelines, which will make it possible to use the freed up personnel in other areas.