Modern Challenges of Energy Conservation
Today, one of the most important tasks of the economy of Ukraine is to reduce energy resource consumption. In this context, self-propelled cars designed for the direct transportation of ore from mining combine harvesters to the working container are becoming important innovations.
Requirements for Electric Drives
Electric drives for such vehicles must meet a number of mandatory requirements:
- Speed regulation range – 5:1.
- Ensuring smooth acceleration and correct braking.
- Correct direction of movement.
- Timely execution of necessary loads.
- Maximum efficiency of braking modes.
Modernization of Electric Drives
One of the main areas of development is radical modernization with active use of frequency-controlled asynchronous electric drives, which are equipped with semiconductor frequency converters and microprocessor control systems.
New Technologies in Frequency Converters
A domestic enterprise has recently developed a unique frequency converter with the following technical characteristics:
- Nominal output current – 32 A.
- Nominal output voltage – 690 V.
- Output frequency range – from 0 to 100 Hz.
- Nominal supply voltage – 690 V.
- Cooling type – air natural.
- Weight – approximately 65 kg.
Power Scheme and Functioning
According to the detailed power scheme, this device includes symmetrical two-link transistor converters on direct current. The main functions are performed by two built-in power blocks.
Filter capacitors maintain electromagnetic compatibility, while a special emergency block enhances operational safety. Reliable switching is ensured by three-phase contacts.
Microprocessor systems consist of several important boards, and the software performs rapid system diagnostics. The microprocessor boards have energy-dependent memory for storing statistical data and fault logs.
Development Prospects
In the future, it is planned to expand the range of frequency converters, in particular, the development of devices with power up to 1200 V. All new models must have a mandatory protection degree of IP54.