Converter for transferring power between DC systems

A converter for transferring power between a p phase AC system of AC voltage V1ac of frequency ω, root mean square line-neutral magnitude V1acm and angle α1, and a DC system of DC voltage V2, the converter comprising:

• an AC/DC converter for transforming DC voltage V2 into a p phase AC voltage V2ac, of frequency ω, root mean square line-neutral magnitude V2acm and angle α2;
• and
• a LCL circuit for each p phase, wherein each LCL circuit comprises two inductors L1,L2 and a capacitor C connected together at their first terminals, the second terminal of inductor L1 being connected to the respective phase of AC voltage V1ac, and the second terminal of inductor L2 being connected to the respective phase of AC voltage V2ac, wherein the second terminals of all capacitors are connected to a common point;
• wherein the value of the capacitor C, inductor L1 and inductor L2 are selected to enable required power transfer and to
• minimise current in inductor L1,
• and/or minimise current in inductor L2.

A converter for transferring power between a first DC system of DC voltage V1 and a second DC system of DC voltage V2, the converter comprising:

• a first AC/DC converter for transforming DC voltage V1 into a first single phase AC voltage V1ac, of frequency ω, root mean square line-neutral magnitude V1acm and angle α1;
• a second AC/DC converter for transforming DC voltage V2 into a second single phase AC voltage V2ac, of frequency ω, root mean square line-neutral magnitude V2acm and angle α2;
• and
• two inductors L1,L2 and a capacitor C, wherein the first terminals of the inductors and capacitor are connected together, the second terminal of inductor L1 and the second terminal of the capacitor C are connected to the first AC voltage V1ac, and the second terminal of inductor L2 and the second terminal of the capacitor C are connected to the second AC voltage V2ac;
• wherein the value of the capacitor C, inductor L1 and inductor L2 are selected to enable required power transfer and to
• minimise current in inductor L1,
• and/or minimise current in inductor L2.

A converter for transferring power between a first DC system of DC voltage V1 and a second DC system of DC voltage V2, the converter comprising:

• a first AC/DC converter for transforming DC voltage V1 into a first p phase AC voltage V1ac of frequency ω, root mean square line-neutral magnitude V1acm and angle α1;
• a second AC/DC converter for transforming DC voltage V2 into a second p phase AC voltage V2ac, of frequency ω, root mean square line-neutral magnitude V2acm and angle α2;
• and a LCL circuit for each p phase, wherein each LCL circuit comprises two inductors L1,L2 and a capacitor C connected together at their first terminals, the second terminal of inductor L1 being connected to the respective phase of the first AC voltage V1ac, and the second terminal of inductor L2 being connected to the respective phase of the second AC voltage V2ac, wherein the second terminals of all capacitors are connected to a common point;
• wherein the value of the capacitor C, inductor L1 and inductor L2 are selected to enable required power transfer and to
• minimise current in inductor L1,
• and/or minimise current in inductor L2.

A converter for transferring power between n DC systems respectively of DC voltage V1i(i=1, 2, . . . n) and m DC systems respectively of DC voltage V2j(j=1, 2, . . . m), where n and m are both any positive integer, the converter comprising:

• n AC/DC converters for respectively transforming DC voltages V1i into respective p phase AC voltages V1iac of frequency ω, root mean square line-neutral magnitude V1iacm and angle α1i;
• m AC/DC converters for respectively transforming DC voltages V2j into respective p phase AC voltages V2jac, of frequency ω, root mean square line-neutral magnitude V2jacm and angle α2j;
• and
• a LCL circuit for each p phase, wherein each LCL circuit comprises n inductors L1i, m inductors L2j and a capacitor C connected together at their first terminals, the second terminal of each inductor L1i being connected to the respective phase of the respective AC voltage V1iac, and the second terminal of each inductor L2j being connected to the respective phase of the respective AC voltage V2jac, wherein the second terminals of all capacitors are connected to a common point;
• wherein the value of the capacitor C, each inductor L1i and each inductor L2j are selected to enable required power transfer and to
• minimise current in inductors L1i,
• and/or minimise currents in inductors L2j.