The crane drive system of TEDF-KM type using SIEMENS frequency converters of SIMOVERT and SINAMICS type is designed for start-up, braking, speed reversal, and change of rotation speed of electric drives for crane mechanisms with short-circuited rotor by means of changing the stator voltage frequency. Such systems ensure smoothness and accuracy of the preset acceleration and braking characteristics, they allow the company to considerably reduce electric power costs, including due to recuperation.
The equipment is located in the metallic cabinets or in the electric room, and can be additionally equipped with the ventilation, air conditioning and heating system. The fluorescent lighting, a metallic lockable container for common needs, a fold-back table and a chair are provided for in the electric rooms.
The panel arrangement provides for the separation of low-power and power parts. The panel for low-power apparatus includes protective start-up automatic machinery, terminal blocks for external connections, programmable logic controller (PLC) and operator’s panel with engineering functions.
The power equipment is placed on the additional mounting panels and grouped according to crane mechanisms. Each panel includes protective start-up automatic machinery for the given mechanism, and also, in case of using individual SIEMENS of SIMOVERT type, frequency converters with surge filters, throttles, and quick-break fuses. The application of the SIEMENS equipment, SINAMICS type, allows the company to considerably reduce the size of the power panel due to its compact dimensions, broad opportunities according to drives grouping, and also to simplify the electric circuit, to exclude individual surge filters and throttles, replacing them by more powerful general analogues. The engines of each crane mechanism are controlled from individual engine module which is switched on to the common dc link. The engine modules are integrated into one or some groups depending on the necessary computational resources for execution of regulation tasks. Each group is controlled by one control module CU320.
The drive control is performed along PROFIBUS-DP network via control modules CU320, from the SIEMENS programmable logic controller (PLC), SIMATIC S7-300 type. The PLC analyzes logic signals from the crane electrical equipment and takes them into account in such a way as to exclude incorrect work of the crane operator, when this can lead to the equipment failure and damage, or contradicts to the safety regulations.
The signals from controllers and signal devices of the cabin are processed by the SIEMENS SIMATIC station of the remote input-output, ET200 type, and after they are transferred along the network PROFIBUS into the controller in digital form, this greatly reduces the quantity of the electrical links between cabin and equipment on the crane gallery.
The SIEMENS HMI operator’s panels of button or sensor types located in the cabin and on panels with electrical equipment perform the role of the visualization device. The current alarm messages and the message archive, states of end switches and frequency converter status words, symbolic circuits of crane chains and many other things are transferred from PLC to the operator’s panel for operative informing of the maintenance personnel.
The availability of the programmable logic controller and the operator’s panel allows the personnel to flexibly control the system, to monitor any troubles during the crane’s work and to inform the technical staff about them, and also to adapt algorithms according to the technological process and operation requirements.
