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The AC electro-mechanical transmission (EMT) control cabinet with efficient liquid cooling system for installation on 220-240-ton dump trucks is a new product among the innovative products of our company. It was created in cooperation with one of the domestic manufacturers of electrical equipment.

Structurally, the new BELAZ cabinet consists of three sections placed in one housing. Two of them are taken up by power inverters, which control electric wheel motors, and modules of interaction with the traction generator. A separate place in the power cabinet is allocated for the section of the autonomous liquid cooling system with a radiator, a pump, a control module and a lot of pipelines and manifolds connecting everything into a single network.

- We aimed to repeat the classic cabinet of our serial models BELAZ-75306, BELAZ-7530G, so that the new power cabinet could fit in its place in terms of dimensions without any particular problems. However, there are some external differences. For example, to facilitate access to electrical equipment the cabinet now has not only front but also side doors, but these changes are visible only to a specialist," says Andrei Kazubenko, head of Electromechanical Transmissions Department of BELAZ Chief Designer Department.

Simply saying the principle of operation of the dump truck power unit with alternating current EMT looks like this: the generator, driven by the diesel engine, generates alternating current, which enters the control cabinet, rectifies and feeds the DC link, which includes a bus with a capacitive filter

The BELAZ control cabinet is hermetically sealed and has a rated protection degree for compartments not related to interaction with the environment - IP54, able to provide reliable protection of power electronics from dust, water and stabilization of the operating temperature of electrical devices, which is very important for the effective operation of dump trucks in the most difficult mining and climatic conditions.

- If we compare it with the BELAZ DC electric drive, the application of AC-AC EMT with a cabinet of our own production in 220-240-ton dump trucks is a switch to a modern, more efficient type of drive with asynchronous motors," emphasizes Andrei Kazubenko. - The advantages are substantial: frequency-controlled asynchronous motors have higher overload capacity and rotation speed, and better weight and size characteristics. At the same time, the absence of the collector and brushes, which require constant control and periodic replacement, significantly reduces the labor intensity of maintenance.

The power part of the control cabinet is based on IGBT units. Microprocessor control, monitoring, protection and diagnostics system, which is a part of the cabinet, allows to provide high energy and operational performance of EMT. Also, due to the absence of wearing parts in the cabinet, it requires less maintenance costs.

Now the BELAZ power cabinet is being tested for proper assembly and connection of all units and modules at low voltage. Then it will be installed on a serial 220-ton dump truck. As part of it, the new EMT control cabinet will be tested at the factory test site.

Developers will set up and monitor the operation of the cabinet, starting with the movement of an empty dump truck in a different speed range on a flat surface and uphill, loading the machine gradually until the body is fully loaded.