General characteristics
The starters provide for:
- start-up of motors with low, average and heavy starting duties;
- motor operation from no load running to a rated load, as well with allowable overloads;
- steady work in transient conditions.
The use of contactless starters allows to:
- save mechanical resource of the motor and related mechanisms due to the lack of starting shocks;
- save the motor’s mechanical resource by reducing the total electrodynamic load on the motor and heating thereof during a start-up process as a result of starting current limitation;
- reduce shock loads on the supply network, ensure the possibility of heavy starts with weak networks;
- save electricity due to an option of possible motor shutdown under no-load condition for a prolonged amount of time.
The starters comply with the requirements of GOST 21558-88, GOST 18142.1-82 and can be used to replace obsolete starters.
- rated currents: from 100 to 1250 A;
- rated voltages: 6 or 10 kV;
- power circuit – three-phase circuit with two opposite connected thyristors on the arm;
- digital control system;
- well-considered object-oriented software;
- custom-tailored algorithm for heavy starting duty;
- increased reliability – switching equipment and electronic components by leading world manufacturers;
- any object orientation at the request of the customer.
High-voltage thyristor soft starter is manufactured according to TU U 31.1-13626132-001: 2008.
The products are certified according to DSTU ISO 9001.
The products are tested successfully according to the approved test procedure. The goods are manufactured in the boreal climate version (UHL), with location environment class 4 according to GOST 15150 and GOST 15543.1. The upper working value of the ambient air temperature is + 40 ° C. The goods allow for operation on altitudes of up to 1000 m and with a dust content in the environment and in cooling air of up to 4 mg/m3. They also accomodate the impact of vibration loads as per group M2 GOST 17516.1, at the same time the upper frequency of range should not exceed 55 Hz.
By using soft starters you can achieve:
- save the motor’s mechanical resource by limiting and controlling the starting current, and thereby reducing the overall electrodynamic load on the motor and its heating during the start-up process;
- reduce shock loads on the supply network, ensure the possibility of start-ups with weak networks;
- due to the fully controlled power circuit, ensure the minimum build-up time of the power circuit and starting of the fan second motor, which is critical for the drive of the main ventilation fan;
- implement automatic switching to direct supply from the network, which ensures the reliability of the scheme.
Note. For each specific fan drive, it is essential to determine if a start-up by a soft-start system is possible, which can be done based on the type of fan, the type and condition of the motor, calculation of the heat equivalent during a start-up, etc.
Main functions
- motor start;
- rotation direction reverse;
- motor shutdown;
- automatic changeover to the shunting switching device (“bypass”) upon start-up completion, and automatic switching from the bypass if controlled braking is required;
- cascade start of several motors.
Control
- Local control – via press button commands on the starter panel;
- Remote control – via contact commands on the drive control dashboard;
- Remote control – via network interface of Automated Process Control System on the level of workshop, plant, etc.
Control system
The control over the thyristor soft starter, protection and alarm, automatic regulation is carried out by a microprocessor control system implemented on the basis of control PWBs.
The control system can be structurally located either in the compartment on the thyristor soft starter door or built as a separate control cabinet. This is defined based on the output (i.e. dimensions) of the powerplant.
The control system is grouped and located in a separate compartment of the power cabinet. Control system PWBs are easy to set up and replace.
The program necessary to alter the controller’s software is available on the company’s website, which allows for implementation of “Internet support” mode, if necessary. In this mode, small software adjustments are made within our enterprise and sent to the Customer in the form of “.exe” files for program alteration.
The converter’s control pulses are being formed directly in the control PWBs. In other PWBs, they are amplified and distributed across the thyristors. All tasks of the control system are performed by software and hardware. The control system produces output signals in the following forms: control pulses on the thyristors, actions on the thyrstor’s protection and switching devices, indication of operating modes and causes of emergency shutdowns, as well as generation of signals for the Customer’s devices. Output signals are compiled to functions of external tasks.
In the close proximity to the thyristors pulse shapers are arranged. The feed of trigger pulses (6.6 ms in duration) to the shapers is implemented using fiber-optic communication lines.
Control of parametric type thyristors breakdown is also carried out on fiber-optic communication lines.
The converter current is measured using current transformers installed in the converter phases.
Micro-processing control systems (CS) of high-voltage soft-starters (HVSS) have the following aspects:
- all range of HVSS have a uniform CS which also is consistent with CSs of other products made by our enterprise, in particular intelligent control panels, troubleshooting systems, devices for remote input/output, exciters of synchronous motors, turbo- and hydro-generators excitations, starters;
- CSs allow to receive and process signals from all sensors – pulse transducers, encoders, syncrodrives, temperature sensors, etc., including sensors with serial lines;
- the component parts for CSs, including low-voltage devices (relays, terminal connectors, etc.) are made of components by world leading manufacturers;
- CSs have high-speed two-wire interfaces for communication with top-level equipment, including equipment from other suppliers;
Interfaces:
- support of network interfaces such as Profibus DP, Modbus RTU, Modbus TCP/IP, PcomplexCAN, CANopen;
- flexible structure of the control and regulation system, open for monitoring and control from Automated Process Control System via network interfaces;
Parameter settings
- detailed settings via a console terminal with a menu in Russian;
- the self-explanatory menu structure of the console terminal allows to adjust the settings without special training for the staff.
- the optimal, baseline parameters for configuration of the soft-starter.
- easily re-programmable functions of input and output control signals.
- further development of soft-starter’s functionality of any complexity by the manufacturer experts as per technical requirements of the Customer.
Protection system
- overcurrent protection;
- overvoltage protection
- overload protection in accordance with the name plate, time-current characteristic of motor g tolerance;
- power circuit disconnection protection;
- open-phase switching-on protection;
- extended start protection;
- protection for no conductivity of thyristors in the converter;
- automatic reclosing upon decrease and/or power outage;
- no-load on the motor protection;
- protection against failure of control system power sources;
- protection against outage or unacceptable drop in station auxiliaries voltage;
- protection against opening of power cabinet doors under high voltage conditions;
- blocking for incorrectly assembled switching equipment circuit.
If there is a breakdown of a single thyristor on one side, the control system generates a warning signal, but HVSS remains in operation. The breakdown of a second thyristor on the same side causes an emergency shutdown of HVSS with corresponding emergency message sent on the console terminal.
There is a forced air cooling with respective availability check. When there is no cooling, a warning message and a warning signal are triggered, and upon the lapse of 3 minutes an emergency shutdown is triggered with a corresponding message thereof.
Diagnostics
- The built-in system records and archives the data on parameters and status of the starter and the motor:
– the number of parameters registered simultaneously – 1 … 16;
– registration time resolution – 3.3 … 100 ms;
– recording fragment duration – 1.5 … 30 sec;
– the number of data fragments archived during emergency shutdowns – 4;
– recording the date and time of archived fragments storing in real-time terms;
– graphical visualization of archived and current data from the recorder via a special-purpose program and diagnostic system on the basis of a portable computer; - electric power meter for energy consumed by the motor – during a start-up and for the set period of operation.
Structural design
Means of local control and administration for the cabinet version:
- “Current phases” device with three phase;
- lamps: “Auxiliaries”, “Readiness”, “Warning”, “Accident”;
- buttons: “Start (Forward)”, “Back”, “Stop”;
- console terminal;
- other means of control and management (optional).
The opposite connected thyristors with individual protective RC-circuits are installed in each phase.
In order to protect the operating staff, the current-carrying power unit is located in a separate compartment.
The door of the power cabinet is equipped with a lock. When the door is open the HVSS is disconnected.
There is a forced air cooling with respective availability check. When there is no cooling, a warning message and a warning signal are triggered, and upon the lapse of 3 minutes an emergency shutdown is triggered with a corresponding message thereof.
The transfer of control pulses and control of parametric type thyristors breakdown is carried out on fiber-optic communication lines.
The converter current is measured using current transformers installed in the converter phases.
The goods are manufactured in the boreal climate version (UHL), with location environment class 4 according to GOST 15150 and GOST 15543.1. The upper working value of the ambient air temperature is + 40 ° C. The goods allow for operation on altitudes of up to 1000 m and with a dust content in the environment and in cooling air of up to 4 mg/m3. They also accomodate the impact of vibration loads as per group M2 GOST 17516.1, at the same time the upper frequency of range should not exceed 55 Hz.
Computer workstation
The supply of soft starters can be completed with an automated workstation – a computerized human-machine interface that can control and monitor an equipment complex.
AWS implements the following functions:
- monitoring and graphical display of a status and parameters for the starters, motors and other equipment;
- control of a start-up, shutdown and other modes of equipment operation;
- duplication of the starter’s console terminal;
- backlog / protocol of equipment operation modes;
- maintenance of hourly and daily data archive from the equipment parameters recorder;
- graphic display of data from parameters recorders embedded into the starter’s controllers.
Structurally, AWS is made, depending on the intended location, in the following versions:
- cabinet rack with built-in industrial computer – for placement directly in the equipment room;
- desktop computer in industrial design for the work position of a controller on duty or an operator;
- industrial computer panel embedded in the panel of an existing equipment control panel.
The recorder
The recorder represents a separate built-in device which main task is to record electrical signals for later viewing on a computer.