DE1941855A1 - Extension of the method for regulating the speed of an electric drive - Google Patents

Description

Extension of the method for regulating the speed of an electric Drive according to claim 4 of the patent file number P 19 19 716.1 The main patent relates to methods and arrangements for regulating the speed of an electric Drive using semiconductors with ignition characteristics, with feed from an alternating current network, using one dependent on the regulated voltage Transducer.

The invention according to the main patent consists according to claim 4 in that to obtain ignition pulses for the semiconductors in the interdependent Load circuits a double base transistor with a pulse capacitor is used, in such a way that the pulse capacitor is supplied with current from two voltage sources, of which one contains a storage element and the switching on and off of both voltage sources takes place via semiconductor switch depending on the Welch selstromnetz on which the electric drive is operated.

If this method is used, then there may be difficulties with ignition the semiconductors occur when the semiconductor to be ignited is connected in parallel Semiconductor is still conductive and therefore not full on the semiconductor to be ignited Operating voltage is present. This occurs especially when there is sudden load or Changes in setpoint values detune the control loop and thus the duration of the current flow of a semiconductor is changed. An ignition pulse falling during the period can do not cause ignition. The failure of the ignition leads to asymmetries, which If the engine is not running smoothly, the gate and electronics may appear are at risk These difficulties become more acute as the case arises Invention solved by the fact that the dependence on the alternating current network is such, that the changing displacement angle between current and voltage is detected instantaneously will. This ensures that the ignition pulse is always given and only then when the operating voltage is applied to the semiconductor.

The basic functional sequence corresponds to that set out in the main patent, wherein in addition to the transformers 66 transformers 711, 721, 731 primary connected to the semiconductors represented by the thyristor groups 71, 72 and 73 are.

The arrangement for carrying out the method according to the invention comprises the following features in detail.

The semiconductor switches (321, 322) for switching the voltage sources on and off, from which the pulse capacitor (425) current is supplied, are from two Stress controlled, one of which is shown via the switching paths of the semiconductors is taken by the thyristor groups (71, 72, 73) in the load circuit.

Furthermore, thyristor groups are parallel to the groups of thyristors in the load circuit 61, 72, 73) transformers (711, 721, 731) connected and the synchronizing stages (31, 32, 33) connected semiconductor switches (311, 322) each have two control inputs and are all connected to a common electronic switching stage (80).

Details of the invention are explained in more detail using a drawing: The circuit arrangements shown in Figures 1 and 2 correspond in principle the main patent ..., ..,. The second input 9o of the synchronization stages has been added 31, 32, 33.

This input receives its voltage from transformers 711 721, 731 connected in parallel to thyristor groups 71, 72 and 734 the dependence on the alternating current network such that the changing angle of displacement between current and voltage is detected momentarily The transformers 711, 721, 731 record the zero crossings of the current while the transformers 66 record the zero crossings of the voltage. The semiconductor switches 321, 3229 via The current supplied to the pulse capacitor 425 is provided by the transformer 721 or 660 (66) controlled. The rest of the functional sequence corresponds to that in the main patent described.

The improvement according to the invention ensures that all ignition pulses also lead to the ignition and thus to the switching on of the load circuit, which leads to asymmetries and the motor does not run smoothly, even when there are strong load fluctuations or sudden changes in the setpoint change the control loop abnormally. The potential risk to the engine and electronics from one-sided loading is thereby also resolved.

Patent claims:

Claims (3)

Patent claims 9 extension of the method according to claim 4 of the patent File number P 19 19 716.1, according to which to regulate the speed of an electric Drive for generating ignition pulses for the semiconductors in each other independent load circuits a double base transistor with a pulse capacitor is used is in such a way that the pulse capacitor is supplied with current from two voltage sources one of which contains a storage element and the switching on and off of both voltage sources takes place via semiconductor switch depending on the alternating current network on which the electric drive is being operated, d u r g e n g e n n a n a l t that the dependence on the alternating current network is such that the changing Shift angle between current and voltage is detected momentarily. 2.) Arrangement for performing the method according to claim 1, d a d u r c h g e k e n n n z e i c h n e t that the semiconductor switches (321, 322) for Switching on and off the voltage sources, of which the pulse capacitor (425) Current is supplied, can be controlled by two voltages, one of which via the Switching paths of the semiconductors, represented by the thyristor groups (71, 72, 73) is taken from the load circuit. 3.) Circuit arrangement according to claim 2 d a d u r c h g e k e n n z e i c h e t that parallel to the thyristor groups (71, 72, 73) transformers (711, 721, 731) are connected. 4e) Circuit arrangement according to claim 2 d a d u r c h g e k e n n z e i c h n e t that the semiconductor switches (321, 322) to synchronizing stages (31, 32 33), each of which has two control inputs, and all of them are connected to a common electronic switching stage (80).