Abstract: For starting an AC electric motor of a mining vehicle, it is first accelerated to a first speed with a second AC voltage provided by an onboard battery-powered inverter of the mining vehicle. A phase of a first AC voltage taken from an external grid is compared to a phase of said second AC voltage. If the phase difference between the first and second AC voltages is larger than a predetermined limit, the speed at which said inverter rotates said AC electric motor is changed. If the difference between the phases of the first and second AC voltages is smaller than the predetermined limit, a change is made from rotating the AC electric motor with the second AC voltage to rotating the AC electric motor with the first AC voltage.

Abstract: The invention relates to a combustion engine and to a process for producing energy by means of expansion work in combustion engines. The invention is based on the problem of providing a possibility for supplying oxygen to the combustion space of a self-compacting combustion engine in an energy-efficient manner. According to the invention, with an arrangement for carrying out an intensified combustion for automatically increasing pressure of the combustion gases and using them in a combustion engine for performing mechanical work, the above-stated problem is solved in that an oxygen storage material is present in the combustion space so that a self-compressing combustion process is made possible by storing the oxygen in the oxygen storage material in the combustion space.

Abstract: For starting an AC electric motor of a mining vehicle, it is first accelerated to a first speed with a second AC voltage provided by an onboard battery-powered inverter of the mining vehicle. A phase of a first AC voltage taken from an external grid is compared to a phase of said second AC voltage. If the phase difference between the first and second AC voltages is larger than a predetermined limit, the speed at which said inverter rotates said AC electric motor is changed. If the difference between the phases of the first and second AC voltages is smaller than the predetermined limit, a change is made from rotating the AC electric motor with the second AC voltage to rotating the AC electric motor with the first AC voltage.

Abstract: The invention relates to a combustion engine and to a process for producing energy by means of expansion work in combustion engines. The invention is based on the problem of providing a possibility for supplying oxygen to the combustion space of a self-compacting combustion engine in an energy-efficient manner. According to the invention, with an arrangement for carrying out an intensified combustion for automatically increasing pressure of the combustion gases and using them in a combustion engine for performing mechanical work, the above-stated problem is solved in that an oxygen storage material is present in the combustion space so that a self-compressing combustion process is made possible by storing the oxygen in the oxygen storage material in the combustion space.