RU37278U1 - ELECTRONIC DISCONNECTOR - Google Patents

Description

Electronic trip unit.

The utility model relates to overcurrent breakers for circuit breakers and is intended to give a command to automatically open circuit breakers of the A3 700 series when a short circuit current or an unacceptable overload occurs in a circuit protected by a circuit breaker.

Known electronic release (RU 2000109925, class Н02 Н 3/24, 2000), including current sensors connected via an output through a circuit for extracting the largest signal with a storage capacitor charge circuit and a circuit for setting the rated current and the multiplicity of short circuit current, the outputs of which are through channels short circuit and overload, respectively connected to the first and second input of the circuit generating a trip signal, the third input of which is connected to the input of the charge circuit of the storage capacitor.

In this case, the sensors are made in the form of nonlinear transformers, the trip elements are made on semiconductor elements of the first generation and on magnetic counters. The release is made on six printed circuit boards connected

between board connections. A disadvantage of the known device is relatively high

the complexity of manufacturing associated with a large number of semiconductor elements mounted on printed circuit boards, which are combined into blocks with a large number of board connections; the need for calibration operations associated with the use of non-linear current transformers; consumer restriction in choosing a type of protection; impossibility

installation of all units in limited volumes of the first-size release for AB A3710.

The basis of this utility model is the task of creating a device whose design allows us to simplify the design of the evaluator and expand its functionality.

The solution to this problem is achieved by the fact that the electronic release, including current sensors connected via the output through the allocation circuit of the largest signal to the charging circuit of the storage capacitor and the circuit for setting the nominal current and the multiplicity of the short circuit current, the outputs of which are connected through short-circuit and refuse channels, respectively the first and second input of the trip signal generation circuit, the third input of which is connected to the output of the storage capacitor charge circuit, according to the utility model tchiki current formed as line transformers, short circuit and overload channels on semiconductor elements assembled for surface mounting on a common circuit board.

In this case, the short circuit and overload channels contain a threshold device and a time delay setting circuit connected in series. Schemes for setting the time delay of the short circuit and overload channels are made on discrete DIP - switches. The threshold device of the short circuit channel is made in the form of an electronic relay on an operational amplifier. The threshold device of the overload channel is made in the form of series-connected pulse generator with a controlled repetition period and a binary counter.

The introduction of these differences allows us to simplify the design of the release and expand its functionality. In addition, the implementation of current sensors in the form of linear current transformers and the execution of time-setting elements on discrete DIP switches allowed to abandon calibration operations

trip units and therefore simplify its setting. The use of semiconductor elements for surface mounting made it possible to combine all the blocks and circuits of the splitter on one printed circuit board, and to reduce the dimensions of the release.

In FIG. Functional diagram of the release is presented.

The electronic release contains current sensors 1, made in the form of linear current transformers. The outputs of the sensors 1 are connected through a circuit 2 for extracting the largest signal from a storage capacitor charge circuit 3 and a circuit 4 for setting the rated current and the multiplicity of the short circuit current. The outputs of circuit 4 are connected to the inputs of channel 5 short circuit and channel 6 overload. Each channel contains a threshold device 7 connected in series and a time delay setting circuit 8. The threshold device 7 of the channel 5 short circuit is made in the form of an electronic relay on an operational amplifier. The threshold device 7 of the overload channel 6 is made in the form of a pulse generator 9 connected in series with a controlled repetition period and a binary counter 10. Schemes 8 for setting the time delay of the short circuit and overload channels are made on discrete DIP switches. The outputs of circuits 8 of channels 5 and 6 are connected respectively to the first and second input of the trip signal generation circuit 11, the third input of which is connected to the output of the storage capacitor charge circuit 3.

The electronic release operates as follows.

With a sharp increase in the current in the network 12 due to an unacceptable load or a short circuit in the network 12, the corresponding largest current pulses from the sensors 1 are transmitted through the circuit 2 for extracting the largest signal to the charging circuit 3 of the storage capacitor and to the circuit 4 for setting the rated current of the release and the multiplicity of the short circuit current (Short circuit). Short circuit and overload signals separated in circuit 4 are fed to threshold devices 7 of channels 5 and 6

respectively. If the permissible values of the threshold currents are exceeded, the corresponding threshold device 7 is triggered and a potential signal about the presence of a short circuit or network overload is issued to the corresponding time delay setting circuit 8. If the potential signal does not disappear during the time specified in circuit 8, it is transmitted to the corresponding control input of the trip signal generation circuit 11. If there is an enable signal at the first and / or second control input of the circuit 11, the discharge capacitor of the circuit 3 is discharged to the control winding of the network switch (not shown in Fig.). Thus, in case of overloads and / or short circuits in the electric network, the release device provides a quick shutdown of the main circuit breaker and, thus, prevents burnout of the power supply wires, elimination of fires and failure of production and domestic electrical equipment.

The utility model is executed at the level of prototypes and their serial development is being prepared.

ICO 3 / rf

Claims (5)

1. An electronic trip switch including current sensors connected through the output of the largest signal extraction circuit to the storage capacitor charge circuit and the circuit for setting the rated current and the multiplicity of the short circuit current, the outputs of which are connected via the short circuit and overload channels to the first and second input of the generation circuit, respectively a trip signal, the third input of which is connected to the input of the storage capacitor charge circuit, characterized in that the current sensors are made in the form of linear transformers to, short circuit and overload channels are assembled on semiconductor elements for surface mounting on a common circuit board. 2. The release according to claim 1, characterized in that the short circuit and overload channels comprise a threshold device and a time delay setting circuit connected in series. 3. The release according to claim 2, characterized in that the circuits for setting the time delay of the short circuit and overload channels are made on discrete DIP switches. 4. The release according to claim 2, characterized in that the threshold device of the short circuit channel is made in the form of an electronic relay on an operational amplifier. 5. The release according to claim 2, characterized in that the threshold device of the overload channel is made in the form of series-connected pulse generator with a controlled repetition period and a binary counter.