Power supply arrangement

Method for manufacturing a frequency converter, in which method:

• a network rectifier as well as an inverter is made from solid-state changeover switches
• wherein:
• an intermediate circuit without a passive energy storage is made between the network rectifier and the inverter
• a network rectifier control is fitted to the frequency converter, and a determination of the phase voltages of the network rectifier is fitted in connection with the control
• the determination is fitted to the frequency converter for detecting an operational deviation
• the determination of an operational deviation is fitted in connection with the breaker of the control of the changeover switches of the inverter.

Power supply arrangement of a transport system, which transport system comprises a transport appliance, and also an electric motor drive for moving the transport appliance, which transport appliance is fitted to be moved with an electric motor, the power supply of which electric motor is fitted to occur with the solid-state changeover switches of the frequency converter connected to the electric motor, which frequency converter comprises a network rectifier which is connected to the alternating electricity source of the transport system, as well as an inverter, which is fitted to the phases of the electric motor, and in which changeover switches an antiparallel-connected diode is fitted in parallel with the controllable switch.

• wherein the aforementioned network rectifier and inverter are connected to each other with an intermediate circuit, which intermediate circuit is implemented without a passive energy storage;
• the positive changeover contact of the network rectifier is controlled to be continuously conductive in the phase of the network rectifier in which the transient value of the phase voltage of the alternating electricity source is greatest, for supplying power between the alternating electricity source and the intermediate circuit;
• the negative changeover contact of the network rectifier is controlled to be continuously conductive in the phase of the network rectifier in which the transient value of the phase voltage of the alternating electricity source is smallest, for supplying power between the alternating electricity source and the intermediate circuit;
• the frequency converter comprises a determination for detecting an operational deviation;
• and the control of the changeover switches of the inverter is fitted to be disconnected on the basis of a determined operational deviation;
• and the movement of the transport appliance is fitted to be stopped by controlling the brake of the transport appliance on the basis of the aforementioned operational deviation.