ENERGY STORAGE SYSTEM
An energy storage system includes a first energy storage branch and a second energy storage branch connected in parallel. The first energy storage branch includes a first battery cluster. The second energy storage branch includes a second battery cluster and a DC/DC converter connected to the second battery cluster in series, with an output end of the DC/DC converter being connected to the second battery cluster. The DC/DC converter is configured to adjust an output current of the second energy storage branch to balance an output current of the first energy storage branch and the output current of the second energy storage branch.
1 . An energy storage system, comprising:
a first energy storage branch comprising a first battery cluster; and
a second energy storage branch connected in parallel to the first energy storage branch and comprising:
a second battery cluster; and
a DC/DC converter connected to the second battery cluster in series, with an output end of the DC/DC converter being connected to the second battery cluster, the DC/DC converter being configured to adjust an output current of the second energy storage branch to balance an output current of the first energy storage branch and the output current of the second energy storage branch.
2 . The energy storage system according to claim 1 , wherein the first energy storage branch does not comprise a DC/DC converter.
3 . The energy storage system according to claim 1 , wherein the output current of the first energy storage branch is adjusted by adjusting the output current of the second energy storage branch by the DC/DC converter.
4 . The energy storage system according to claim 1 , wherein the second energy storage branch further comprises:
a switch unit connected in parallel to the DC/DC converter, the first switch unit being configured to turn on or off the DC/DC converter.
5 . The energy storage system according to claim 4 , wherein the switch unit is further connected in series to the second battery cluster and configured to control operation of the second battery cluster.
6 . The energy storage system according to claim 4 , wherein the switch unit includes a relay.
7 . The energy storage system according to claim 1 , wherein the first energy storage branch further comprises:
a switch unit connected in series to the first battery cluster and configured to control operation of the first battery cluster.
8 . The energy storage system according to claim 1 , wherein two input ends of the DC/DC converter are connected to two ends of at least one battery of the second battery cluster, respectively.
9 . The energy storage system according to claim 8 , wherein the two input ends of the DC/DC converter are connected to a positive electrode and a negative electrode of the second battery cluster, respectively.
10 . The energy storage system according to claim 1 , wherein the DC/DC converter is powered by a power supply independent of the energy storage system.
11 . The energy storage system according to claim 1 , further comprising:
a main control unit configured to control operation of the DC/DC converter according to state information of the first battery cluster and state information of the second battery cluster.
12 . The energy storage system according to claim 11 , further comprising:
a first sub control unit configured to collect the state information of the first battery cluster and transmit the state information of the first battery cluster to the main control unit; and
a second sub control unit configured to collect the state information of the second battery cluster and transmit the state information of the second battery cluster it to the main control unit.
13 . The energy storage system according to claim 11 , further comprising:
a power conversion unit configured to provide the main control unit with a total demand power of the energy storage system;
wherein the main control unit is further configured to control the operation of the DC/DC converter according to the total demand power, the state information of the first battery cluster, and the state information of the second battery cluster.
14 . The energy storage system according to claim 13 , wherein:
the power conversion unit includes an AC/DC converter; or
the DC/DC converter is a first DC/DC converter and the power conversion unit includes a second DC/DC converter.
15 . The energy storage system according to claim 1 , further comprising:
a first sub control unit configured to collect state information of the first battery cluster; and
a second sub control unit configured to:
collect state information of the second battery cluster;
receive the state information of the first battery cluster transmitted by the first sub control unit; and
control operation of the DC/DC converter according to the state information of the first battery cluster and the state information of the second battery cluster.
16 . The energy storage system according to claim 1 , wherein the DC/DC converter includes an isolated DC/DC converter.
17 . The energy storage system according to claim 1 , wherein the DC/DC converter includes a non-isolated DC/DC converter.
18 . The energy storage system according to claim 1 , wherein the first battery cluster is formed by a plurality of batteries connected in series and/or in parallel.
19 . The energy storage system according to claim 1 , wherein the second battery cluster is formed by a plurality of batteries connected in series and/or in parallel.
20 . The energy storage system according to claim 1 , wherein the output end of the DC/DC converter is connected to a positive electrode or a negative electrode of the second battery cluster.