*5.1.1. Capacity test*

**Figure 11.** The proposed advanced cell to cell battery balancing topology.

Table 1.

Switches Suffering High Voltage Stress

102 New Applications of Electric Drives

Balancing Type Between Adjacent

**Table 1.** Dear authors, please add caption

**5. Experimental validation**

**5.1. Battery test**

in the laboratory.

Cells

In this topology, the two adjacent cells, which share one winding (*C*1and *C*<sup>2</sup> for instance), would form a buck-boost converter similar to that of Topology 1. Meanwhile, due to the coupled windings, non-adjacent cells (*C*1and *C*4 for instance) and its windings form a Flyback converter. So balancing could be easy, no matter if the cells are adjacent or not. The cell to cell balancing method is realized and is considered to be time-saving. To compare this topology with the other above-stated topologies, the components needed for an *n* cell string are compared in

Windings n-1 2n n+1 n/2 Ferrite Cores 0 n 1 1 Switches 2n-2 2n n+1 n

> Between Cell and String

As shown in Table 1, for the proposed topology, only one switch and one winding are needed for each cell. All the switches used in the proposed topology will not suffer high voltage stress. The cost would be dramatically reduced and the controlling complexity will also be lower.

To learn the characteristics of the battery, different types of battery tests have been taken out

**Topology 1 Topology 2 Topology 3 Proposed Topology**

0 n 1 0

Between Cell and

String Between Arbitrary Cells

Capacity test is firstly carried out to obtain the actual capacity of the battery.[71] The testing results are as shown in Figure 12.

**Figure 12.** Testing results of the capacity test.

### *5.1.2. Hybrid pulse power characterization test*

The Hybrid Pulse Power Characterization (HPPC) Test is intended to determine the dynamic power capability over the device's useable charge and voltage range using a test profile that incorporates both discharge and regeneration pulses. The results are as follows:

**Figure 13.** Testing results: (a) HPPC test when discharging; (b) HPPC test when charging.
