Frequency converter, frequency converter assembly, and control method thereof
AssigneeSiemens Aktiengesellschaft
InventorYa Jun Zhou
Life of this patent
Estimating the term…
Abstract
A frequency converter adapted to be connected to another frequency converter via a direct current bus is provided. The frequency converter comprises: a positive bus interface adapted to be interconnected with a positive bus interface of the other frequency converter; an external bleeder resistor interface adapted to be interconnected with an external bleeder resistor interface of the other frequency converter; and a first control logic which controls a parallel connection, between the frequency converter and the other frequency converter and realized by a direct current bus, to be turned on or off. A corresponding frequency converter assembly, a control method, and a computer readable storage medium are also provided.
Claims17
A frequency converter for connection to another frequency converter via a DC bus, wherein the frequency converter includes a higher power than the other frequency converter, the frequency converter comprising:
- a positive bus interface configured to connect to a positive bus interface of the other frequency converter;
- an external bleeder resistor interface configured to connect to an external bleeder resistor interface of the other frequency converter, and
- a first control logic configured to turn on and off a bus parallel connection between the frequency converter and the other frequency converter, the bus parallel connection provided by the DC bus;
- wherein when a bus voltage increases above a reference value by greater than or equal to a preset threshold value, the first control logic is configured to turn on the bus parallel connection to provide bus voltage sharing between the frequency converter and the other frequency converter;
- wherein when the bus voltage decreases below the reference value, the first control logic is configured to switch off the bus parallel connection to avoid where a rectifier bridge of the other frequency converter bears a current demand of the frequency converter.
A frequency converter assembly comprising:
- a first frequency converter;
- a second frequency converter, wherein the second frequency converter includes a lower power than the first frequency converter;
- and
- a DC bus;
- wherein positive bus interfaces of the first frequency converter and the second frequency converter are connected to each other and external bleeder resistor interfaces of the first frequency converter and the second frequency converter are connected to each other,
- wherein a first control logic of the first frequency converter controls a bus parallel connection between the first frequency converter and the second frequency converter to be turned on or off, wherein the bus parallel connection is provided by the DC bus;
- wherein when a bus voltage increases above a reference value by greater than or equal to a preset threshold value, the first control logic is configured to turn on the bus parallel connection to provide bus voltage sharing between the first frequency converter and the second frequency converter;
- wherein when the bus voltage decreases below the reference value, the first control logic is configured to switch off the bus parallel connection to avoid where a rectifier bridge of the second frequency converter bears a current demand of the first frequency converter.
A control method for a frequency converter assembly comprising a first frequency converter, a second frequency converter and a DC bus, wherein the second frequency converter includes a lower power than the first frequency converter, wherein positive bus interfaces of the first frequency converter and the second frequency converter are connected to each other and external bleeder resistor interfaces of the first frequency converter and the second frequency converter are connected to each other, the control method comprising:
- controlling a bus parallel connection between the first frequency converter and the second frequency converter to be turned on or off, wherein the bus parallel connection is provided by the DC bus;
- wherein when a bus voltage increases above a reference value by greater than or equal to a preset threshold value, the first control logic is configured to turn on the bus parallel connection to provide bus voltage sharing between the first frequency converter and the second frequency converter;
- wherein when the bus voltage decreases below the reference value, the first control logic is configured to switch off the bus parallel connection to avoid where a rectifier bridge of the second frequency converter bears a current demand of the first frequency converter.
A non-transitory computer implemented storage medium that stores machine-readable instructions configured to:
- turn on or off a bus parallel connection between a first frequency converter and a second frequency converter of a frequency converter assembly that comprises the first frequency converter, the second frequency converter and a DC bus,
- wherein positive bus interfaces of the first frequency converter and the second frequency converter are connected to each other and external bleeder resistor interfaces of the first frequency converter and the second frequency converter are connected to each other;
- wherein the bus parallel connection is provided by the DC bus;
- wherein when the bus voltage increases above a reference value by greater than or equal to a preset threshold value, the machine-readable instructions are configured to turn on the bus parallel connection to provide bus voltage sharing between the first frequency converter and the second frequency converter;
- wherein when the bus voltage decreases below the reference value, the machine-readable instructions are configured to switch off the bus parallel connection to avoid where a rectifier bridge of the second frequency converter bears a current demand of the first frequency converter.
Dependencies are inferred from the claim text.