SU936172A1

SU936172A1 - Device for thermal protection of electric equipment

Info

Publication number: SU936172A1
Application number: SU792854250A
Authority: SU
Inventors: Игорь Григорьевич Кропачев
Original assignee: Ленинградский Завод Радиотехнического Оборудования
Priority date: 1979-12-18
Filing date: 1979-12-18
Publication date: 1982-06-15

Description

1one

Изобретение относитс к электротехнике и может быть использовано дл температурной защиты электроустановок . The invention relates to electrical engineering and can be used for temperature protection of electrical installations.

Известно устройство дл защиты асинхронного электродвигател при опрокидывании,содержащее источник питани и подключенный к его зажимам делитель напр жени ,, выполненный на последовательно соединенных термодатчике и потенциометре, исполнительный и коммутирующий элементы D3A device for protecting an asynchronous electric motor during tipping is known, which contains a power source and a voltage divider, connected to its terminals, made on series-connected thermal sensors and a potentiometer, executive and switching elements D3

Недостатком данного устройства вл етс его низка надежность работы . Это вызвано тем, что при обрыве цепи термодатчика или цепи питани устройство не отключает установку при ее работе в аварийном режиме.The disadvantage of this device is its low reliability. This is because when the circuit of the thermal sensor or the power supply circuit is broken, the device does not turn off the unit during its operation in emergency mode.

Наиболее близким по техническому решению к изобретению вл етс устройство дл температурной защиты электродвигател , содержащее источник питани с подключенными к егоThe closest technical solution to the invention is a device for thermal protection of an electric motor, containing a power source with connected to it

зажимам двум делител ми напр жени , первый из которых выполнен на резисторах и термодатчике, а второй - на исполнительном органе и ключевом элементе (тиристорном ключе и коммутип рующий элемент, шунтирующий цепь исполнительного органа 2}.the clamps are two voltage dividers, the first of which is made on resistors and a temperature sensor, and the second on the actuator and the key element (a thyristor key and a switching element that shunts the circuit of the executive organ 2}.

Недостатками устройства вл ютс его сложность и отсутствие коррекции устройства по току установки.The drawbacks of the device are its complexity and the lack of correction of the device according to the installation current.

Цель изобретени - повышение на дежности работы устройства.The purpose of the invention is to increase the reliability of the device.

Поставленна цель достигаетс тем, что ключевой элемент выполнен на транзисторе, а коммутирующий элемент шунтирован дополнительно введенным конденсатором, кроме того, при ис- , пользовании в качестве источника питани датчиков тока первый делитель напр жени подключен к нестабилизиро-ванному выходу источника питани .The goal is achieved by the fact that the key element is made on a transistor, and the switching element is shunted by an additional capacitor, moreover, when using the current sensors as the power source, the first voltage divider is connected to the unstabilized output of the power source.

Claims

The drawing shows a diagram of the device. 393 The device contains a power source 1, a voltage splitter connected to its terminals, made on series-connected thermal sensor 2 and potentiometer 3, performing k and switching 5 (dynistor) elements. A second voltage divider connected to the power supply terminals and made on the actuator, a resistor 6 and a transistor switch 7, the input of which is connected to the output of the potentiometer of the first voltage divider, is additionally introduced into the device. The outputs of the voltage dividers are shunted by the switching element. A switching element is shunted by a capacitor 8. When using current sensors as the power source, the first voltage divider can be connected to the unstabilized 9 output of the power source. The switching element can be made on a dynistor or an analogue of a single junction transistor. The device operates as follows. In the initial state, the voltage and the output of the power supply 1 is zero. The dynistor 5 and the transistor switch 7 are closed. The actuator is disabled. The sensor 2 is installed on a controlled element of the installation 8 as the source of power supply 1 is -. Used current transformer. When power supply 1 is turned on, distor 5 remains closed, since resistance of sensor 2 is significantly greater than resistance of potentiometer 3 and voltage drop on potentiometer 3 is less than switch voltage of dynistor 5. At the same time, transistor 7 opens, the actuator generates a command to turn on the installation. . When an overload occurs, the elements of the installation heat up, the resistance of the thermal sensor 2 decreases, and the voltage drop on the potentiometer 3 increases. The dynistor 5 opens and shunts the actuator k, which forms a command to shut down the installation. It is possible to re-activate the installation when the temperature of the elements reaches the nominal value. The capacitor 8 is designed to more reliably switch the dynistor 5. In the event of a break in the circuit of the thermal sensor 2, the transistor 7 is closed, and when the circuit of the thermal sensor 2 is short-circuited, the distor 5 is opened. In both cases, the actuator is switched off. Switching the thermal sensor circuit 2 to an unstabilized voltage of the power source 1 corrects the installation. -V Claim 1, A device for thermal protection of an electrical installation containing a power source with two voltage dividers connected to its terminals, the first of which is made on resistors and temperature sensor, and the second on the executive body and the key element (thyristor key), and the switching element, which shunt the circuit of the executive body, characterized in that, in order to increase the reliability of you, the key element is made on the transistor, and the switching element is shunted by an additional capacitor. . 2. The device according to claim 1, 1.0 tons l and that is so that when using the current sensors as the power source, the first voltage divider is connected to the unstabilized output of the power source. Sources of information taken into account during the examination 1. USSR author's certificate No. 543083, cl. H 02 N7 / 08,1977.

2. USSR author's certificate No. 357644, cl. H 02 H 7/08, 1972.