RU2274869C2 - Method for controlling electro-technical state of electric machines - Google Patents

Abstract

FIELD: electric engineering, possible use for express control of serviceability of electric machines, in particular, electric engines, generators of direct, alternating currents and transformers.

SUBSTANCE: method for controlling electro-technical state of electric machines includes connecting device to electric machine in non-operative state, producing oscillating or non-periodic process in winding circuit of electric machine. If oscillating process is registered in windings of electric machine, then electric machine is considered to be functional. If non-periodic signal is observed, electric machine is considered non-functional. As a result, there is no need for stand tests in conditions of electric workshop or control-test station, economical efficiency is improved, operation costs are reduced, serviceability control of all types of electric machines is provided , for example, for direct current machines, stepping, linear, asynchronous alternating current motors, synchronous machines, and also all types of transformers, while remote control over technical state of electric machines is provided for remotely positioned control subject.

EFFECT: possible operative control of working state of electric machines by connecting a control device to machine, checking its electric parameters in static (disconnected from power grid) mode.

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Description

The invention relates to electrical engineering, in particular to a method for monitoring the operating condition of electrical machines.

In electrical engineering, when testing electric machines, a method is known (see the Instruction of the Ministry of Railways of the departments of wagon economy and locomotives of TsTVR No. 4099 “Testing electric vehicles of rolling stock in railway transport”), in accordance with GOST: GOST 25000, GOST 25941, GOST 11929, GOST 11929, GOST 11929, GOST 12379, ST 1107 - methods for determining the resistance of windings without disconnecting the machine from the network, using specially designed stands. The following electrical tests of machines are performed on bench equipment: measuring the insulation resistance of the windings relative to the machine body; measurement of active and reactive resistance of windings; checking the electrical strength of the interturn insulation of the windings. The disadvantage of an analogue is low-performance control of the parameters of an electric machine.

Periodic testing of electrical machines is carried out in certain time frames established by standards or specifications. The purpose of periodic tests is to make sure that during the production or operation, the technical quality of electric machines has not changed significantly compared with the results of acceptance tests.

However, the known methods for monitoring the electrical state of machines have the following disadvantages. A significant drawback of the analogue is removal from rolling stock or from the equipment of an electric machine to assess the technical condition. In addition, for testing machines, the manufacture and use of special stands is required.

The prototype of the proposed method is (see Russian patent No. 1035742, A N 02 K 23/12, 1983, BI No. 30) "Method for controlling the switching of DC machines", the implementation of this method is carried out using a device consisting of a capacitor and indicator, included into the additional excitation winding of the electric motor. This method allows you to determine the quality of switching the armature by changing the magnetic flux in the gap of the main poles of the electric machine.

Despite its simplicity, this method of control has the disadvantage of controlling only one parameter of the machine — switching disturbance.

The technical task of the invention is the express control of the state parameters of electrical machines and their control circuits by connecting to the windings of a diagnostic device. This device provides a characterization of the transient, which is used to judge the quality of the technical condition of the electric machine.

The proposed method differs from the existing one in that: voltage is applied to the windings of an electric machine periodically through a switching device from the plates of a charged capacitor from a direct current source. The indicator, which includes an analog-to-digital converter (ADC) and a personal electronic computer (PC), determines the nature of the transition process [Fig.1]. In this case, in the case of a healthy condition of the engine, the nature of the process is oscillatory [figure 2], otherwise (open circuit, inter-turn winding closure, impaired switching of the armature and other defects) the aperiodic nature of the transition process [figure 3].

The control device for the electrical condition of electrical machines includes the following elements:

1. The power source;

2. Capacitor;

3. Switching device (electronic key);

4. The input device, the Converter "current - voltage";

5. The measuring device, consisting of: analog-to-digital Converter (ADC); devices for selecting and storing information, PC;

6. The control unit.

The value of the capacitor C and the resistance R are selected experimentally for each type of the tested electric machine.

The measuring device allows using the resistance R to coordinate the control circuit with the test object, and using the capacitor C, the device is tuned to the oscillatory mode of the control circuit of the electric machine.

The process of monitoring the state of an electric machine is as follows. When a constant voltage is applied, the capacitor C charges through a series-connected resistance R. When the switching device is turned on, the capacitor is discharged to the winding of the electric machine, and a transient occurs in the circuit. The nature of the transition process evaluate the technical condition of the electric machine. If the machine is operational, the nature of the transition process is oscillatory, otherwise (malfunctioning state of the machine) - the transition process is aperiodic.

An experiment was conducted on a series of arrow DC motors of the type MSP-0.25, MSP-0.15.

Using the invention will allow: to quickly identify directly in the workplace equipment failures in electrical machines, DC, AC and transformers. The effectiveness of control is expressed in the reduction of operating costs during periodic inspection of machines, a qualitative improvement in working conditions and safety.

Claims (1)

A method for monitoring the electrical condition of electrical machines using a connection to the windings of the machine, a capacitor, an indicator and a constant voltage source, as well as monitoring the indicator of the technical condition of the machine, characterized in that voltage is applied to the windings of the machine disconnected from the mains supply through the switching device from the DC voltage source of the capacitor and the indicator determines the nature of the transient process, while in case of good condition In the case of a machine, the nature of the transition process is oscillatory, otherwise the nature of the transition process is aperiodic.

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