CN110838804A - Starting circuit - Google Patents
Starting circuit Download PDFInfo
- Publication number
- CN110838804A CN110838804A CN201911134017.5A CN201911134017A CN110838804A CN 110838804 A CN110838804 A CN 110838804A CN 201911134017 A CN201911134017 A CN 201911134017A CN 110838804 A CN110838804 A CN 110838804A
- Authority
- CN
- China
- Prior art keywords
- resistor
- starting
- circuit
- voltage
- motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P1/00—Arrangements for starting electric motors or dynamo-electric converters
- H02P1/16—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters
- H02P1/18—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual dc motor
- H02P1/20—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual dc motor by progressive reduction of resistance in series with armature winding
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Motor And Converter Starters (AREA)
Abstract
The invention discloses a starting circuit, and belongs to the technical field of power generation. The starting circuit provided by the invention comprises a motor, a starting resistor, an electronic switch and a contactor, wherein the motor and the starting resistor are arranged in series, the electronic switch and the starting resistor are arranged in parallel, the electronic switch is used for being conducted to short-circuit the starting resistor in the starting process of the motor, the contactor is conducted to short-circuit the electronic switch after the motor is started, and the electronic switch is recovered to the cut-off state. Because the voltage drop after the electronic switch is conducted is smaller than the voltage drop before the starting resistor is short-circuited, the voltage values at two ends of the contactor are smaller when the contactor is closed and conducted, the probability of generating large electric arcs is reduced, and the probability of burning out or sticking the contacts of the contactor is also reduced.
Description
Technical Field
The invention relates to the technical field of power generation, in particular to a starting circuit.
Background
The direct current motor has the remarkable characteristics that: the starting current is large, the maximum impact current can reach 15-20 times of the rated current, and the direct current power supply system is subjected to larger current impact. In order to reduce the starting current of the direct current motor, a series resistance starting mode can be adopted, namely: when starting, the starting resistor R is connected in series with the armature loop of the motor, and the resistor R plays roles of voltage reduction and current limitation. After the direct current motor is started to increase the speed, the direct current contactor 1KM is used for short-circuit of the starting resistor, so that the direct current power supply voltage is completely applied to the armature winding of the direct current motor, and the motor enters a normal operation working condition.
However, in the actual starting process of the motor, when the contactor 1KM with the short-circuit starting resistor R is switched on, large arcs are easily generated at two ends due to large voltage, so that the contact of the contactor 1KM is burned out or stuck.
Disclosure of Invention
In order to solve the above problems, the present invention provides a starting circuit capable of preventing an arc from being generated during a starting process of a dc motor.
In order to solve the above problems, the present invention provides a starting circuit, which includes a motor, a starting resistor, an electronic switch, and a contactor:
the motor comprises a first end and a second end, and the first end of the motor is connected with the anode of the power supply;
the starting resistor comprises a first resistor end and a second resistor end, the first resistor end is connected with the second motor end, and the second resistor end is connected with the negative electrode of the power supply;
the electronic switch is connected in parallel with the starting resistor, the electronic switch is used for conducting in the starting process of the motor to short-circuit the starting resistor, and the conducting voltage drop of the electronic switch is smaller than the voltage drop of the starting resistor before short-circuit;
the contactor is connected with the starting resistor in parallel, and the contactor is used for conducting after the motor is started so as to short-circuit the electronic switch.
In the starting circuit, the starting circuit further comprises a control component, and the control component is used for driving the electronic switch to be switched on when the voltages at the two ends of the motor reach the preset value.
In the above starting circuit, the electronic switch includes an anode, a cathode and a control electrode; the anode is connected with the first end of the resistor, and the cathode is connected with the second end of the resistor; the control assembly is connected with the control electrode and used for triggering the conduction of the anode and the cathode.
In the starting circuit, the control component includes a trigger circuit, the trigger circuit is connected in parallel with the starting resistor, and the trigger circuit includes a trigger switch, a first voltage-dividing resistor and a second voltage-dividing resistor, which are sequentially connected in series, and a trigger end arranged between the first voltage-dividing resistor and the second voltage-dividing resistor; the trigger switch is used for switching on or off the trigger circuit, the trigger end is connected with the electronic switch, and trigger current generated by the trigger circuit enters the electronic switch through the trigger end.
In the starting circuit, the control assembly further comprises a measuring part, the measuring part is used for monitoring a voltage value between the first end of the motor and the second end of the motor, the measuring part is linked with the trigger switch, and the trigger switch is driven to be closed when the voltage value reaches the preset value.
In the above starting circuit, the trigger switch is a contact of the relay, and the measuring element is a measuring element of the relay.
In the above starting circuit, the first voltage dividing resistor is a sliding resistor, and/or the second voltage dividing resistor is a sliding resistor.
In the above starting circuit, the electronic switch is a thyristor.
In the above starting circuit, the preset value is 50% to 60% of the power supply voltage.
In the starting circuit, the contactor is switched on after the electronic switch is switched on and through a preset time delay.
The starting circuit provided by the invention comprises a motor, a starting resistor, an electronic switch and a contactor, wherein the motor and the starting resistor are arranged in series, the electronic switch and the starting resistor are arranged in parallel, the electronic switch is used for being conducted to short-circuit the starting resistor in the starting process of the motor, the contactor is conducted to short-circuit the electronic switch after the motor is started, and the electronic switch is in a cut-off state. Because the voltage drop after the electronic switch is conducted is smaller than the voltage drop before the starting resistor is short-circuited, the voltage values at two ends of the contactor are smaller when the contactor is closed and conducted, the probability of generating large electric arcs is reduced, and the probability of burning out or sticking the contacts of the contactor is also reduced.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a functional block diagram of a start-up circuit in an exemplary embodiment of the invention;
fig. 2 is a specific circuit schematic diagram of the start-up circuit according to the embodiment of the invention.
Reference numerals:
100-a start-up circuit; 10-a control assembly; 20-a trigger circuit; a D-motor; r-starting resistance; 1 KM-contactor; d1-electronic switch; K1-Relay; k11-trigger switch; k12-measuring piece; r1 — first divider resistance; r2-second divider resistor.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Generally, after the direct current motor is started to increase the speed, the direct current contactor 1KM is used for short-circuiting the starting resistor, so that the direct current power supply voltage is completely applied to the armature winding of the direct current motor, and the motor enters a normal operation working condition. However, in the actual starting process of the motor, when the contactor 1KM with the short-circuit starting resistor R is switched on, large arcs are easily generated at two ends due to large voltage, so that the contact of the contactor 1KM is burned out or stuck. If the contact of the contactor is stuck and is not found in time, the direct-current power supply system has great potential safety hazards, and safety accidents are easy to happen. To solve the problem of burning out or sticking of the contacts of the contactor, there are two solutions for those skilled in the art: 1) the starting mode of the direct current motor soft starter is adopted, the starting mode has good effect, but the investment is large, as a plurality of computer electronic control devices are added, the complexity of a system and a control loop is increased, and the reliability of the device is not high; 2) the starting resistor R is divided into a plurality of resistors which are connected in series, a plurality of direct current contactors are used for short circuit switching step by step in sequence, the mode needs to be composed of a plurality of direct current contactors with large capacity, an intermediate relay and a time relay, and the mode has the defects of more elements, too many links, extremely high fault rate, very crowded cabinet body and extremely inconvenient overhauling and maintenance. In the starting process, any one stage of resistor is not switched, so that the direct current motor cannot normally run, and the resistor generates heat to cause accidents.
Therefore, the starting circuit for the direct current motor is provided, the starting circuit can solve the problem that large arcs are generated in the starting process of the direct current motor, does not need investment of a large number of resources, and is convenient to overhaul and maintain and high in reliability.
In the embodiments of the present invention, the connection includes a direct connection with a direct contact, and also includes an indirect connection without a direct contact.
Fig. 1 is a block diagram of a start-up circuit 100 according to an embodiment of the invention. The starting circuit 100 comprises a motor D, a starting resistor R, an electronic switch D1 and a contactor 1 KM. The motor D is a direct current motor D and comprises a first end of a motor and a second end of the motor, and the first end of the motor is connected with the anode of the power supply. The starting resistor R comprises a first resistor end and a second resistor end, the first resistor end is connected with the second end of the motor, and the second resistor end is connected with the negative pole of the power supply. The starting resistor R is connected with the motor D in series, and can play a role in voltage reduction and current limitation so as to reduce the maximum impact current in the starting process of the motor D. The electronic switch D1 is arranged in parallel with the starting resistor R, the electronic switch D1 can be conducted in the starting process of the motor D, and the conducting voltage drop required by the electronic switch D1 is smaller than the voltage drop before the starting resistor R is short-circuited, so that the electronic switch D1 is reliably conducted in the starting process of the motor D, and the starting resistor R is short-circuited after being conducted. Contactor 1KM and starting resistance R parallel arrangement, contactor 1KM can switch on after motor D starts to accomplish, and contactor 1KM is closed back not only starting resistance R by the short circuit, and electronic switch D1 is also by the short circuit. Because the voltage drop of the electronic switch D1 is less than the voltage drop before the starting resistor R is short-circuited, the voltage values at the two ends of the contactor 1KM are smaller when the contactor is closed and conducted, so that the probability of generating large arcs is reduced, and the probability of burning out or sticking the contact of the contactor 1KM is also reduced.
The starting circuit 100 may further include a control component 10, where the control component 10 is used in a starting process of the motor D, specifically, when a voltage across the motor D reaches a preset value, the electronic switch D1 is driven to be turned on, and the starting resistor R is shorted. The conduction voltage drop across the electronic switch D1 is typically small so that the voltage from the power source is almost entirely applied to the motor D and the motor D completes the start-up process. After the motor D is started, the contactor 1KM may turn on the short-circuit electronic switch D1, so that the starting circuit 100 completes the starting operation of the motor D. The electronic switch D1 can be turned on automatically and timely by the setting of the control assembly 10.
Wherein the preset value may be 50% to 60% of the supply voltage, such as 53% of the supply voltage, 55% of the supply voltage, or 58% of the supply voltage, etc.
Electronic switch D1 includes an anode, a cathode, and a control electrode. Specifically, the anode is connected to a first end of the resistor, the cathode is connected to a second end of the resistor, and the control assembly 10 is connected to the control electrode, and is configured to trigger the anode and the cathode to be conducted through the control electrode.
The control assembly 10 includes a trigger circuit 20, the trigger circuit 20 being arranged in parallel with a firing resistor R. The trigger circuit 20 includes a trigger switch K11, a first voltage-dividing resistor R1, and a second voltage-dividing resistor R2 connected in series in this order, and a trigger terminal disposed between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. Specifically, trigger switch K11 has switch first end and switch second end, and first divider resistance R1 includes partial pressure first end and partial pressure second end, and second divider resistance R2 includes partial pressure third end and partial pressure fourth end, and the first end of switch first end connecting resistance, the first end of partial pressure is connected to the switch second end, and partial pressure second end and partial pressure third end are connected the trigger end, and the fourth end connecting resistance second end of partial pressure. The first switch end and the second switch end of the trigger switch K11 can be jointed or separated, when the trigger switch K11 is jointed, the trigger circuit 20 is closed and the trigger circuit 20 is conducted, and when the trigger switch K11 is separated, the trigger circuit 20 is opened and the trigger circuit is turned off. The trigger terminal is arranged between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the trigger terminal is connected with the control electrode of the electronic switch D1, and the voltage across the second voltage-dividing resistor R2 is equal to the voltage between the control electrode and the cathode of the electronic switch D1, so that a forward stable trigger voltage is applied to the electronic switch D1, and a stable trigger current is provided.
The control assembly 10 further comprises a measuring member K12, the measuring member K12 is used for measuring the voltage value between the first end and the second end of the motor, and the measuring member K12 is linked with the trigger switch K11 to drive the trigger switch K11 to close when the voltage value between the two ends of the motor D reaches a preset value, so that the trigger switch K11 can be closed or opened timely and automatically.
Specifically, the trigger switch K11 is a contact of the relay K1, wherein the first end of the switch is a movable contact, the second end of the switch is a stationary contact, the measuring piece K12 can be a measuring element of the relay K1, and the measuring element of the relay K1 can be an induction coil of the relay K1, so that the linkage setting of the trigger switch K11 and the measuring piece K12 is realized. Relay K1 may be a voltage relay or an intermediate relay. Of course, the measuring member K12 may not be a measuring element of the relay K1, but may be another element capable of monitoring the voltage across the motor D, and correspondingly, the trigger switch K11 may not be a contact of the relay K1 but a switch linked with the measuring member K12.
The electronic switch D1 may be a thyristor having an anode, a cathode and a control electrode as described above, and the on-state peak voltage of the thyristor is less than 2.6V. Of course, the electronic switch D1 may also be other electronic components that can be triggered to turn on or off, and will not be described in detail.
In the embodiment of the invention, the contactor 1KM is turned on after the electronic switch D1 is turned on, and in order to prevent the contactor 1KM from being turned on before the electronic switch D1, the contactor 1KM is turned on after a preset time delay. The predetermined delay is a short delay within 1 second, such as 0.1 second, 0.3 second, 0.5 second, 0.7 second, or 0.9 second, etc.
In the starting circuit 100 of the embodiment of the invention, in the normal operation process of the motor D, if the contactor 1KM is disconnected due to some fault reason or the main contact is burnt and damaged due to overheating, the starting resistor R is switched in abnormally in the operation, or the starting resistor R is shunted abnormally, so that the voltage at two ends of the starting resistor R is increased, at this time, because the voltage between the anode and the cathode of the electronic switch D1 is greater than the required conduction voltage, the trigger circuit 20 triggers the thyristor to be conducted, the electronic switch D1 short-circuits the starting resistor R, so that an accident caused by long-term overcurrent heating of the starting resistor R is avoided, and the normal operation of the motor D.
Fig. 2 is a schematic circuit diagram of the start-up circuit 100 according to the embodiment of the present invention, and the operation and principle thereof will be described below.
When the motor D is started, the main contactor-KM is closed, the motor D is connected with a starting resistor R in series, and the starting current of the motor D is as follows:
in the formula: r-starting resistance, R-motor winding resistance, U-supply voltage.
Since r is generally small, the above formula can be written as:
the voltage of the starting resistor R is:
UR＝U-UD
in the formula: u shapeD-motor voltage.
The motor voltage is small at the initial starting time of the motor D, and the motor D is driven along with the increase of the rotating speed of the motor DMechanical voltage UDAlso increases gradually, when the coil of the relay K1 (i.e. the measuring part K12) detects UDAt the time of U being equal to or more than (50% -60%), the movable contact and the fixed contact of the relay K1 are jointed (namely the trigger switch K11 is closed), the trigger circuit is switched on, the two ends of the first divider resistor R1 and the second divider resistor R2 are both provided with voltage, and forward stable trigger voltage is added between the control electrode and the cathode of the controllable silicon to provide stable trigger current. At this time, the voltage U between the two ends of the starting resistor RRApproximately (40% -50%) U, which is equivalent to the voltage of (40% -50%) U between the anode and the cathode of the controlled silicon, the controlled silicon meets the conduction condition and is conducted, the controlled silicon is in short circuit with the starting resistor R, and the motor D runs at full voltage.
In order to prevent the contactor 1KM from closing before the silicon controlled rectifier, 1KM is started after short time delay. When the main contact of 1KM is closed instantaneously, because of URThe voltage is the on-state voltage of the controllable silicon, namely about 0.7V, which is equivalent to that the main contact of 1KM is connected with an equipotential line, so that the main contact of 1KM can not generate electric arcs.
When the main contact of 1KM is closed, the voltage U at two ends of the starting resistor RRAnd the voltage is approximately equal to 0V, the voltage between the anode and the cathode of the controlled silicon is approximately 0V, the controlled silicon is turned off, the current flows through the main contact of 1KM, the steady-state switching of a current loop is completed, and the starting process of the motor D is completed.
In the normal operation process of the motor D, the starting resistor R is connected abnormally in the operation process of the motor D due to the disconnection of a certain fault reason or the overheating and burning loss of a main contact and the like, or the starting resistor R is shunted abnormally, so that the UR voltage is increased, at the moment, the voltage between the anode and the cathode of the electronic switch D1 is greater than the required conduction voltage, the trigger circuit triggers the silicon controlled rectifier to be conducted, the silicon controlled rectifier is in short circuit with the starting resistor R, the accident caused by the long-term overcurrent heating of the starting resistor R is avoided, and the normal operation of the motor.
Therefore, the starting circuit provided by the embodiment of the invention can effectively solve the problems that the closing arc of the contactor 1KM is large when the starting resistor R is short-circuited, and the contact of the contactor 1KM is burnt out and stuck, thereby not only ensuring the safe starting of the direct-current motor D, but also prolonging the service life of the contactor 1KM, preventing the shutdown caused by the fault of the contactor 1KM in the running of the direct-current motor D, and improving the running reliability of equipment.
The controllable silicon can be a common unidirectional controllable silicon, and relevant parameters are selected as follows: the model is as follows: KP 500A; rated on-state current (I)T) Selecting 2-3 times of rated current of the motor, such as 500A; reverse withstand voltage (V)RRM): 3-4 times greater than the supply voltage, e.g., 1800V; trigger current (I)GT): 25-200 mA; trigger voltage (V)GT)≤2.5V。
The relevant parameters of the first divider resistor R1 and the second divider resistor R2 are selected as follows: i isGTSelecting 100-200 mA; the resistance value of R1+ R2 should be 50% U/IGTWherein R2 should be greater than 2.5/IGT1,IGT1Selecting 25-50 mA; in a 220KV power supply system, the first voltage dividing resistor R1 is a 100W/500 and 1000 omega porcelain tube adjustable winding sliding rheostat; the second voltage dividing resistor R1 is a ceramic tube adjustable wire-wound sliding rheostat with 100W/50-100 omega.
The first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 are sliding resistors, so that the sliding head of the sliding rheostat can be adjusted in the field, and the thyristor can be triggered under different voltages, such as the voltage of (30% -50%) U.
If the relay K1 is a direct-current intermediate relay, the starting voltage of the relay is 50% -60% U, and the relay K1 can be a ZJY-420G type DC220V relay specifically; in the case of a dc voltage relay, the relay operating voltage should be (50% -60%) U.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A starting circuit, comprising a motor, a starting resistor, an electronic switch and a contactor:
the motor comprises a first end and a second end, and the first end of the motor is connected with the anode of the power supply;
the starting resistor comprises a first resistor end and a second resistor end, the first resistor end is connected with the second motor end, and the second resistor end is connected with the negative electrode of the power supply;
the electronic switch is connected in parallel with the starting resistor, the electronic switch is used for conducting in the starting process of the motor to short-circuit the starting resistor, and the conducting voltage drop of the electronic switch is smaller than the voltage drop of the starting resistor before short-circuit;
the contactor is connected with the starting resistor in parallel, and the contactor is used for conducting after the motor is started so as to short-circuit the electronic switch.
2. The starting circuit according to claim 1, further comprising a control component for driving the electronic switch to conduct when the voltage across the motor reaches a preset value.
3. The start-up circuit of claim 2, wherein the electronic switch comprises an anode, a cathode, and a control electrode; the anode is connected with the first end of the resistor, and the cathode is connected with the second end of the resistor; the control assembly is connected with the control electrode and used for triggering the conduction of the anode and the cathode.
4. The starting circuit according to claim 2, wherein the control component comprises a trigger circuit, the trigger circuit is arranged in parallel with the starting resistor, the trigger circuit comprises a trigger switch, a first voltage-dividing resistor and a second voltage-dividing resistor which are sequentially arranged in series, and a trigger terminal arranged between the first voltage-dividing resistor and the second voltage-dividing resistor; the trigger switch is used for switching on or off the trigger circuit, the trigger end is connected with the electronic switch, and trigger current generated by the trigger circuit enters the electronic switch through the trigger end.
5. The starting circuit according to claim 4, wherein the control assembly further comprises a measuring member for monitoring a voltage value between the first end of the motor and the second end of the motor, the measuring member being coupled to the trigger switch to actuate the trigger switch to close when the voltage value reaches the predetermined value.
6. A starting circuit according to claim 5, characterized in that the trigger switch is a contact of a relay and the measuring element is a measuring element of the relay.
7. The power up circuit of claim 4, wherein the first voltage dividing resistor is a sliding resistor, and/or the second voltage dividing resistor is a sliding resistor.
8. The startup circuit of claim 1, wherein the electronic switch is a thyristor.
9. The power up circuit of claim 2, wherein the preset value is 50% to 60% of the power supply voltage.
10. The starting circuit of claim 1, wherein the electronic switch is turned on and then the contactor is turned on with a predetermined delay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911134017.5A CN110838804B (en) | 2019-11-19 | 2019-11-19 | Starting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911134017.5A CN110838804B (en) | 2019-11-19 | 2019-11-19 | Starting circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110838804A true CN110838804A (en) | 2020-02-25 |
| CN110838804B CN110838804B (en) | 2021-12-07 |
Family
ID=69576689
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911134017.5A Active CN110838804B (en) | 2019-11-19 | 2019-11-19 | Starting circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110838804B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2870264Y (en) * | 2005-10-10 | 2007-02-14 | 余志东 | Composite switch |
| CN201655447U (en) * | 2010-02-09 | 2010-11-24 | 浙江沪龙电机有限公司 | Resistor used for motor driver in stoppage |
| CN101997301A (en) * | 2010-08-06 | 2011-03-30 | 许晓华 | Start protecting circuit of low-voltage and high-power motor |
| CN201789458U (en) * | 2010-07-06 | 2011-04-06 | 保定卓尔电气有限公司 | Smooth soft start device of direct-current motor |
| CN105470917A (en) * | 2015-12-08 | 2016-04-06 | 中国大唐集团新能源股份有限公司 | Overtemperature protection apparatus for fan frequency converter cabinet |
| CN108736771A (en) * | 2018-04-28 | 2018-11-02 | 保定中恒电气有限公司 | A kind of the strong of dc motor encourages circuit, control circuit and equipment |
-
2019
- 2019-11-19 CN CN201911134017.5A patent/CN110838804B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2870264Y (en) * | 2005-10-10 | 2007-02-14 | 余志东 | Composite switch |
| CN201655447U (en) * | 2010-02-09 | 2010-11-24 | 浙江沪龙电机有限公司 | Resistor used for motor driver in stoppage |
| CN201789458U (en) * | 2010-07-06 | 2011-04-06 | 保定卓尔电气有限公司 | Smooth soft start device of direct-current motor |
| CN101997301A (en) * | 2010-08-06 | 2011-03-30 | 许晓华 | Start protecting circuit of low-voltage and high-power motor |
| CN105470917A (en) * | 2015-12-08 | 2016-04-06 | 中国大唐集团新能源股份有限公司 | Overtemperature protection apparatus for fan frequency converter cabinet |
| CN108736771A (en) * | 2018-04-28 | 2018-11-02 | 保定中恒电气有限公司 | A kind of the strong of dc motor encourages circuit, control circuit and equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110838804B (en) | 2021-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101237137A (en) | Over voltage and under-voltage device | |
| CN110581541A (en) | surge current suppression circuit with isolation control | |
| US11087934B2 (en) | Arc-quenching device for direct current switch | |
| CN115764818A (en) | Safety protection low-voltage circuit breaker circuit | |
| CN110838804B (en) | Starting circuit | |
| CN106099882A (en) | The anti-firing circuit of big electric current with power-off protection | |
| CN103296946A (en) | Driver of brushless electric machine and circuit thereof | |
| CN109412466B (en) | Steam turbine emergency direct-current lubricating oil pump composite start-stop device and control method | |
| CN101030738B (en) | Motor control device | |
| CN112769004A (en) | Method for eliminating direct current system socket arc and device and application thereof | |
| CN215009570U (en) | Overload protection circuit for soft start, soft start device and electronic equipment | |
| CN214959336U (en) | Motor starting circuit | |
| CN112636637A (en) | Motor starting circuit | |
| CN105391292A (en) | Low-voltage startup circuit | |
| CN211531021U (en) | Circuit and device for compositely starting and stopping emergency lubricating oil pump of steam turbine | |
| CN220964318U (en) | Power converter protection device and power conversion system | |
| CN115296569B (en) | Generator excitation arc-free de-excitation device and de-excitation method | |
| CN218384793U (en) | On-load tap-changer | |
| CN220653352U (en) | Protection device with function of limiting trigger current of silicon controlled rectifier | |
| CN214101179U (en) | Control switch for reducing loss of starting surge power tube | |
| CN111911441B (en) | Locomotive fan control circuit | |
| CN219268479U (en) | Overvoltage and undervoltage protection circuit | |
| CN217469455U (en) | Multi-voltage direct-current overvoltage protector | |
| CN217135154U (en) | Contactor direct current start control circuit based on electric capacity | |
| CN210954257U (en) | Current breaking device for testing instantaneous large current of direct-current power relay |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |