Structure: PLC control
Control circuit voltage : automatic / manual function
Control circuit voltage: 220V/50Hz,control supply current not surpass 10A. equip automatic and manual control function, HV voltage output speed keep at 1kV±10%; time setting: 1S-99 hour, current can setting random, over-current action time ≤10ms; equip constant interlock function; when automatic control, control console has accuracy reference voltage, its instability less than 1%, the different between real voltage and reference voltage less than 1%, regulating accuracy reach 1%; most of the component, contactor, button, relays are imported.
Function: equip with over-voltage and puncture voltage protection device, electric component are Omron, SIEMENS and other big company products.
All meters are digital display, below items are display on the interface:
1. measuring winding voltmeter accuracy not less than 1 grade
2. Capacitance voltage divider voltmeter not less than 1 grade
3. equip with regulator input voltmeter, regulator input amperameter, regulator output amperameter, test transformer output amperameter, compensation reactor compensating amperameter, test transformer output voltmeter, HV output amperameter, accuracy not less than 1 grade.
4. Set voltage regulator upper and lower position limited protection and automatic zero.
5. raise voltage and reduce voltage function, withstand timing (can setting the withstand time according to each test requirement.), over-current protection.
6. equip with switchgear cabinet switch-on and switch-off function, switchgear cabinet interlock function, emergency button, alarming bell, door interlock, indicating lamps.
7. Fast recover over-voltage protection
8. Control console has error display and regulator back-zero function
Voltage adjust range: according to the system (Max setting 1650kV) Setting accuracy: 0.1kV
1. System Introduction
1.1 The control table will be connected with its switch cabinet through optical fiber so as to isolate the main system equipment from the control unit and prove safety control of the system.
1.2 The key components and control panel are used of high quality imported parts.
1.3 Control, program writing, software update is available.
1.4 With functions of control, measurement, protection and interlocks, and can realize automatically control.
2. Main Structure of System
The system is composed by operating interface and PLC control unit.
2.1 The operating interface is mounted on the control table which is located in control room. So that the testing transformer can be controlled at site acc. to different test requirements, data of control and measurement will be transmitted via 2-core optical fiber.
2.2 The PLC control unit is mounted at switch cabinet side which connected with the interface via 2-core optical fiber.
3. System Functions:
3.1 Separated sub-interface for different control of the transformer.
3.2 Emergency stop buttons of each interface are available for cut off power supply of the system and shut down the test. The functions can be set and operated through touch screen.
3.3 Control Functions:
Open/Close of Primary side of the regulator;
Open/Close of Secondary side of the regulator;
Step-up time setting;
Step-down time setting;
Setting of Timer;
Turn Ratio Setting of the Divider;
Setting of Current Protection Value;
Setting of Voltage Protection Value;
Reset of Protection State;
Operation of Alarming Bell & Lights;
Timing Operation: timing will be driven automatically after push down start button. When arrived the setting time point, the alarming will start and keep for 2 min, then the system will step down.
Automatic Control: Preset of voltage value, step-up/step-down speed and timing data, then push down start button for realizing of the whole process.
3.4 Measurement Display
Secondary voltage of regulator (i.e. Primary winding voltage of testing transformer) : accuracy 1%
Secondary current of regulator (i.e. Primary winding current of testing transformer) : accuracy 1%
Voltage of Divider (i.e. Secondary winding voltage of testing transformer): accuracy 1%
Secondary winding current of testing transformer: accuracy 1%
The high voltage value of discharge can be recorded.
3.5 State Display and Indication:
Correctness of phase sequence;
Close or open state indication of regulator primary switch;
Close or open state indication of regulator secondary switch;
Position Limit indication of regulator step-up / step-down;
Over current Protection;
Protective device action of switch cabinet;
Interlock/Indication between test field door and switch-on operation;
Interlock/Indication of non-release of emergency button;
Interlock/Indication of operation when the regulator set not at lowest position;
The reactor is stepless adjustable unit and controlled manually of the motor for adjustment of air-gap. The relevant current value will be indicated and with showing of capacitive current compensated.
Interlock of isolating switch ON and vacuum circuit breaker ON;
Interlock of vacuum circuit breaker OFF and isolating switch OFF;
Interlock of vacuum circuit breaker close and failure set lowest position of regulator;
Test field door opened, vacuum circuit breaker cannot be closed;
Emergency stop button not released, vacuum circuit breaker cannot be closed;
Circuit breaker closed, tripping off automatically when the door opened;
Only regulator primary closed first, the secondary can be closed;
When the primary tripped off, the secondary do same action automatically;
Circuit breaker tripped off, the regulator will go down to the lowest position;
When the regulator is live, if the control power suddenly cut off, the vacuum breaker will trip off. After the system be switched on again, the regulator will return to Zero Limit Position. Otherwise, the breaker could not be turned on again. In test process, if test object is breakdown, overcurrent protection will act and the front pole switch and rear pole circuit breaker will trip off and the regulator will return to Zero Position. Otherwise, the close operation of front pole switch and vacuum breaker cannot be carried out.
The switch cabinet has current and voltage protection components which separated away from the control system. When set
protection value reached, the protective actions work accordingly and its action will be indicated on the interface of control system.
The current protective value of regulator primary and secondary can be set through control system. When the set value reached, the system trip off automatically.
Control Functions: Change-over between auto and manual control as per operator order input. Close /open of switch is under control; automatic step-up / step-down and emergency open while being failure; the speed of step-up can be controlled automatically, that means high speed of step-up is done before 75% test voltage and the speed slow down beyond 75% test voltage.