CN208046489U

CN208046489U - A kind of direct current oil pump soft starting device of none-disk terminal contactor

Info

Publication number: CN208046489U
Application number: CN201820010305.4U
Authority: CN
Inventors: 赵占强
Original assignee: SHAANXI YILIAN ELECTRICAL EQUIPMENT CO Ltd
Current assignee: SHAANXI YILIAN ELECTRICAL EQUIPMENT CO Ltd
Priority date: 2018-01-04
Filing date: 2018-01-04
Publication date: 2018-11-02
Anticipated expiration: 2028-01-04

Abstract

The utility model is related to a kind of direct current oil pump soft starting device of none-disk terminal contactor, ensure that direct current pump start process is steady, to straight-flow system and motor without impact.It is characterized in that the starter passes through high-power electric power semiconductor device IGBT and high frequency chopping reduction technology, by direct current oil pump non-impacting start and stopping, after startup, pass through the straight-through completion start-up course of IGBT, eliminate traditional straight universal contactor, the contactor for reducing high failure rate, reduces maintenance and failure rate, increases the stability and reliability of system.

Description

A kind of direct current oil pump soft starting device of none-disk terminal contactor

Technical field

The utility model is related to a kind of power plant lubricating oil system direct current oil pump soft starting devices.

Background technology

Currently, in thermal power generation system, in the lubrication of steam turbine bearing, sealing oil system, generally alternating current-direct current is used to supply The mode of electricity, under normal circumstances, exchange Oil pump electrical machinery work, and when fault in ac transmission system cannot work, start spare Direct-current oil pump motor.Due to when starting direct-current oil pump motor, will produce prodigious dash current, not only the winding of motor is made At injury, DC protection system can be also impacted when serious, caused relay protection and automatic device to malfunction, caused the accident.It passes The Starting mode of system is to reduce starting current by sealing in resistance in the armature circuit of direct current generator, is passed through again after timing D.C. contactor short circuit resistance completes start-up course.

Traditional string resistance Starting mode is easy to cause the contact of D.C. contactor to burn bonding, causes equipment fault not It can start；Although this mode reduces starting current, but still be 3 times of rated current or more, to motor and straight-flow system Still there is impact.So the Starting mode high failure rate of this string resistance, maintenance workload is big, and resistor heating loss amount is big.

Invention content

In order to eliminate above-mentioned disadvantage, the utility model provide it is a kind of be made of power electronics semiconductor device IGBT it is straight Oil pump soft start-up control device is flowed, none-disk terminal contactor, no consumption energy, starting current is small, no impact, and system is reliable and stable.

In order to achieve the above objectives, the utility model adopts the following technical solution：

The resistance actuator being serially connected between motor and power supply is changed to the BUCK chopping depressuring circuits being made of IGBT, On startup, main contactor is attracted, and BUCK chopping depressuring circuits electrification, controller sends out PWM modulation waveform, by adjusting duty Than, adjust the turn-on and turn-off of IGBT, duty ratio is bigger, and the output voltage of chopping depressuring circuit is higher, duty ratio from 0 to 100%, the voltage of motor is just raised to rated voltage from 0V, and the rotating speed of motor is raised to rated speed from 0, and the conducting of IGBT perseverances is completed to open Dynamic process.When stopping, adjusting duty ratio and drop to 0 from 100%, voltage drops to 0V from rated voltage, and main contactor disconnects, and motor stops Only.By setting time of the duty ratio from 0 to 100%, start the time to set, the time is longer, and start-up course is more steady.

After start-up course, by giving mono- normal open signal of IGBT, IGBT is straight-through to connect motor and power supply, avoids use Bypass contactor is led directly to, and is reduced device, is increased reliability.

Description of the drawings

Fig. 1 is BUCK chopping depressuring circuit diagrams

Fig. 2 is direct current oil pump Soft Starting System schematic diagram

Fig. 3 is device arrangements figure

Fig. 4 is start-up logic block diagram

Fig. 5 is to stop logic diagram

Specific implementation mode

The utility model is further elaborated with specific implementation below in conjunction with the accompanying drawings：

Shown in FIG. 1 is the typical BUCK reduction voltage circuits in power electronics teaching material, opening and closing by adjusting V in figure Break, i.e. the duty ratio of V, to control output voltage.It is with formula expression：

Wherein：E_mFor output voltage

E is input voltage

T_onFor the service time of IGBT

T is the chopping cycle of IGBT

Therefore by from T_on0 is raised to T, that is, completes the process for output voltage being increased to input voltage, that is, complete Start-up course.And the setting of startup time can be completed by setting the time of this process.Conversely, can be in setting time 0 is inside reduced the voltage to, realizes the function that soft stop is stopped.

Fig. 2 show direct current oil pump Soft Starting System schematic diagram, and system dc voltage DC is accessed by contactor KM1, first Excitation of direct current generator coil power supply, excitation voltage is given to be transferred to PLC by TV2 voltage transmitters, exciting current passes through TA2 electric currents Transmitter is transferred to PLC, meanwhile, IGBT starts to increase service time, duty ratio is improved, within the set time output voltage Rated voltage is increased, start-up course is completed.Capacitance C1 mainly carries out voltage regulation filtering, current transducer TA1, electricity to output voltage Armature voltage and armature supply are transferred to PLC by pressure transmitter TV1, are detected and are protected.Pointer voltmeter V1 and pointer electricity Flow table is then intuitively shown on the door of disk cabinet.Wherein current divider FL1 is that DC current is changing into a 75mV signal It is indicated to pointer ammeter.

Fig. 3 show device arrangements figure, and device arrangements divide right and left power loop and control loop, avoids interfering, Part, right side are power loop part in order to control in middle left side.Wherein bottom right 1 is high current terminal block, for connecting In situ DC The access of electrical source of power and the power supply of direct current generator pick out；2 be direct current current divider FL1, and DC current is transformed into direct current 75mV signals, which export, gives pointer DC ammeter；3 be armature supply transmitter TA1, and punched-type current transducer can allow busbar It is passed through from interstitial hole；4 be contactor KM1, and for turning on and off power supply, but not loaded-up, no arc light generates；5 be use In the power electronic devices IGBT of chopping depressuring；6 be filter capacitor C1.Left side is control section, wherein 7 be Switching Power Supply, it is main The supply of 24V and 15V power supplys is provided for PLC and driving plate；8 be IGBT driving plates, and driving IGBT work is used；9 be Siemens PLC, all control logics, parameter setting and protection etc.；10 be 24V terminal blocks, for concentrating the 24V of all devices to supply； 11 convert various states and signal conversion for intermediate relay；12 be electric current, voltage transmitter, by armature voltage, excitation voltage 4-20mA signal transmissions are converted into PLC with exciting current;13 be external connection terminal block, controls and shows for field external Signal transmission connection.

Fig. 4 is that PLC starts logic chart, after PLC receives enabled instruction, is first closed contactor KM1, at this moment direct current generator Excitation is charged, and detects excitation voltage and whether electric current is normal, returned when abnormal, is disconnected KM1, is just carried by IGBT if normal High duty ratio boosts to the armature voltage of motor, when duty ratio is, indicates that IGBT has been led directly to, the armature of motor Voltage has had reached rated voltage, and at this moment start-up course terminates.

Fig. 5 is that PLC stops logic chart, after PLC receives halt instruction, reduces the duty ratio of IGBT first, is dropped to from 1 After 0, armature loss of voltage disconnects KM1 at this time, and excitation of direct current generator disappears, and motor stops.

Claims

1. a kind of direct current oil pump soft starting device of none-disk terminal contactor, the direct current oil pump soft starting device is connected to live straight It flows between power-supply system and direct-current oil pump motor, the direct current oil pump soft starting device, including DC power supply input unit, IBGT Copped wave unit, capacitor filtering unit and voltage and current detecting unit, feature are as follows：

The DC power supply input unit is made of contactor KM1, and straight-flow system power supply accesses system on startup, by KM1 System, then carries out startup control by IBGT copped waves unit；Be also when stopping after IGBT copped wave units reduce the voltage to 0, In the case of not having load current, direct-current oil pump motor and straight-flow system are detached from；

The IGBT copped waves unit is made of IGBT, fly-wheel diode and filter capacitor, when startup, when IGBT is connected, and electricity Pressure is added on direct current generator and filter capacitor, and when IGBT ends, the equivalent inductive reactance potential on direct-current oil pump motor passes through afterflow Diode discharge, forming circuit, and the duty ratio of IGBT conductings is bigger, DC output voltage is higher, defeated when duty ratio is 1 Go out voltage and be equal to straight-flow system voltage, completes start-up course；

The capacitor filtering unit, is made of direct current capacitors C1, ensures the continuity of direct current output when IGBT copped waves And smoothness, avoid the mutation of voltage to the impact of system；

The voltage and current detecting unit is made of TV1, TV2, TA1, TA2, FL1, A1 and V1, and wherein V1 is direct current pointer electricity Table is pressed, intuitively shows the armature voltage of direct-current oil pump motor, can be clearly visible armature voltage in start-up course slowly rises Process；FL1 and A1 is that DC current is shown, DC current signal is converted into 75mV voltages letter by DC current current divider Number, then intuitively shown by ammeter A1；TV1, TV2, TA1, TA2 are voltage and current Hall sensor, are by armature Voltage, excitation voltage, armature supply and exciting current are converted into 4-20mA signals, are transferred to PLC and are detected and protect, simultaneously It can be with teletransmission to centralized control system.

2. direct current oil pump soft starting device according to claim 1, it is characterised in that：PLC directly controls the copped wave of IGBT, It can accomplish the control to IGBT, eliminate the bypass contactor of IGBT, avoid the arc light pair when contactor switching DC load The damage in the service life of contactor ensure that the stability and reliability of system, maintenance are low.