SU797050A1 - Device for brushless excitation of synchronous machine - Google Patents

Description

(54) DEVICE FOR BRUSHLESS EXCITATION OF SYNCHRONOUS MACHINE

one

The invention relates to electrical engineering and can be used in systems for controlling the excitation current of synchronous machines, mainly for contactless excitation systems.

There are known devices for brushless excitation of electric masks that contain a driver exciter, a main electric machine and a system for controlling the excitation current. The disadvantage of these devices is the need to ensure the transmission of control pulses from the control system to the rotating rotor of the main machine on which the thyristors are located. Either pulsed transformers or capacitors are used to transmit pulses, which complicates the design and reduces reliability.

Also known are devices for driving synchronous machines, made in the form of an asynchronous machine. a phase rotor, called asynchronous exciters or dynamic transformers, on the stat of which voltage and serial windings 2 are located.

Such devices have reduced reliability and also require the introduction of an additional device to provide initial self-excitation, which complicates the system and eliminates the possibility of autonomous operation of synchronous machines.

The closest in technical essence to the invention is a device for brushless excitation of a synchronous machine, comprising a dynamic transformer, designed as an asynchronous machine with magnetically coupled serial windings and voltage windings, each serial winding is connected in series with one of the synchronous winding phases - machines, and a control system consisting of groups of anti-parallel-connected controlled gates according to the number of phases of the asynchronous machine and the control system my vents h. ,

Regulation in this device

This is accomplished by connecting the winding of the voltage of the asynchronous exciter to the phases of the synchronous machine by means of series on. simmistorov. In this pathogen

To ensure the initial self-excitation of a synchronous machine, external sources of voltage are required to provide opening of the simistor, which complicates the whole device in the absence of the indicated sources, the simistors connected with the winding do not open the self-excitation circuit, not providing the initial self-excitation. In addition, with the loss of valve functions by simms, it is possible that the driver of the synchronous machine itself and the load connected to it will fail. It then happens that as a result of the probing of the unifigurable voltage of the synchronous machine, the synchronous machine goes directly to the coil voltage of the asynchronous exciter and causes an increase in the excitation current, and consequently, an excessive increase in the voltage of the synchronous machine. The latter occurs until the saturation of the magnetic circuits or damage to the windings of the asynchronous machine or excitation device occurs. The purpose of the invention is to provide an initial self-excitation and increase reliability. The goal is achieved by adding additional compounding resistances connected in series to the synchronous machine phase and synchronous transformer voltage windings in a device for brushless excitation of a synchronous machine, and each group of controlled valves is connected to the winding of a dynamic transformer in one group the connection point with the compounding resistance, and the other conclusions of the groups of controlled valves are interconnected. FIG. 1 shows a diagram of the proposed device, one of the options; in fig. 2 - the same, another option. The device for brushless excitation comprises a dynamic transformer, made in the form of an asynchronous machine with a winding of 1 phase rotor and windings 2 and 3 of the series and voltage located on the stator (Fig. 1). An additional winding 4 can be located on the stator (Fig. 2). Parallel to the winding 3 of the voltage or parallel to the auxiliary winding 4, the controlled valves 5 are connected, which are controlled through the pulse unit B by means of the regulator 7. A current of the stator 8 of the synchronous machine flows through the serial winding 2. The voltage winding 3 is connected via the compounding resistance 9 to the phases of the synchronous machine, the winding of the 1-phase rotor is connected to the rectifier 10 connected to the excitation winding 11. The device works as follows. The initial self-excitation of the synchronic machine is carried out along the circuit: the stator 8 of the synchronous machine, the compounding resistance 9, the winding 3 of the voltage, the winding 1 of the rotor, the rectifier 10 and the winding 11 of the residual voltage excitation. When the synchronous machine runs at idle and under fiarpysk, a current is induced in the rotor winding proportional to the geometric sum of the windings 2 and 3. The induced current passing through the rectifier 10 falls into the excitation winding 11 of the synchronous machine. High regulation accuracy in static and dynamic modes is achieved by opening controlled valves 5, bypassing voltage winding 3 or additional winding 4. As a result, the current required to change the excitation of a synchronous machine is connected to the chain of controlled valves. The proposed device provides reliable self-excitation, as well as increased reliability while maintaining high control accuracy in static and speed, in dynamic modes, and by providing initial self-excitation and increased reliability, it provides reliable self-excitation and operation of autonomous synchronous machines excitation systems. Formula. The device for brushless excitation of a synchronous machine, comprising a dynamic transformer, designed as an asynchronous machine with magnetically coupled serial windings and voltage windings, each serial winding is connected in series with one of the phases of the synchronous machine winding, an adjustment system consisting of opposite groups - in parallel, interconnected controlled gates according to the number of phases of the asynchronous machine and the control circuit of said gates, characterized in that, in order to To increase reliability and ensure reliable initial excitation, additional compounding resistances are introduced, connected in series between the phases of a synchronous machine and the windings of a dynamic transformer, each group of controlled valves is connected to the output winding of a single terminal.

Claims (3)

Formula inventions A device for brushless excitation of a synchronous machine, containing a dynamic transformer, made in the form of an asynchronous machine with magnetically connected series windings and voltage windings, each series winding is connected in series with one of the phases of the synchronous machine winding, a control system consisting of groups of counter-parallel connected between controlled valves according to the number of phases of the asynchronous machine and control circuits of said valves, characterized in that, in order to increase the reliability minute and provide a reliable and early * Nogo self-excitation, introduced additional compounding of resistance connected in series between the phases of the synchronous machine and the transformer windings dynamic voltage controlled valves, each group connected to one terminal of the coil voltage dina5 The transformer at the connection point with the compounding co-> by gravity, and other conclusions of the groups of controlled gates are interconnected. 1. Converting devices' and excitation systems of synchronous machines. Ed. Glinternik S.R. L., Science, 1973, p. 152. 2. Copyright certificate of the USSR 139707, class.GN 02 P 9/38, 1968. 3. Copyright I certificate of the USSR No. 286042, cl. H 02 P 9/14, 1970.