IEEE Electrification - June 2021 - 18

runs out. Figure 15 shows some AMP
products and experimental prototypes
for comparison.
Control of dc-dc Converters
Like any other power electronic converters,
dc-dc converters are controlled
by microcontrollers (such as a
digital signal processor, a field-programmable
gate array, and so on)
via drive circuits to achieve the de -
signed performance and perform
protection schemes. In this section,
some common control functions for
dc-dc converters, such as output
voltage regulation, input/output current
regulation, and interleaving and
current-balancing control for interleaved converters, are
briefly reviewed.
Additional equipment,
such as speakers,
screens, electric
steering systems, and
computing systems
for autonomous
driving, increases
the load on the
12-V system.
controller can also be a nonlinear one,
such as a sliding-mode controller, to
handle the intrinsic nonlinearity of
power electronic converters.
Dual-loop control strategies are
more common and effective than single-loop
ones in controlling power
electronic converters. Figure 17 is a
block diagram of a dual-loop control
that contains inner and outer loops.
The outer voltage loop is normally
used to produce the current reference
for the inner current loop. The inner
current loop is designed for the faster
dynamic response of the converter's
requirement. A feedforward path (as
shown in Figure 18) can also be added
to either the single-loop or the dual-loop control to
increase the converter's response speed.
Model predictive control (MPC) has gained increased
Voltage and Current Regulation
Voltage or current regulation can be achieved via a singleloop
control scheme. Figure 16 shows a single-loop control
diagram to regulate the dc-link voltage for a boost dc-dc
power converter. The voltage error goes to the controller to
generate the duty ratio control signal, which is then used
to produce the corresponding pulsewidth modulation
(PWM) signals to turn the switch on and off. The controller
can be a classic proportional-integral (PI), proportionalintegral-derivative,
phase-lead, phase-lag, or other type of
linear controller, such as a type III controller. If a linearized
model of the converter is developed, then a linear controller
can be readily based on the classic control theory. The
interest in dc-dc converter control. For an MPC control
scheme, a prediction model is first established according
to the equivalent circuit model of the converter under different
operating conditions. A cost function is then built to
evaluate the performance of the converter. Finally, the
switching state in the next sampling period is determined
by minimizing the cost function, which reduces the
switching transition.
Interleaving and Current-Balancing
Control for Interleaved Converters
The interleaving control can be achieved by shifting the
phase angle of the gate signal for each phase by 360°/N for
Martek Power
(PS2450)
90% at 2,078 W
250-420 V/
12.5-13.54 V
TDI Power
Brusa
(LSM3k0-400-12)
94% at 3 kW
180-450 V/9-16 V
(BSC623-12V-B)
93.5% at 3.5 kW
190-425 V/
8-16V
Digital Control and
Modulation
HF-TransFormer
Water
Cooler
(Top)
Bel Power
(350DNC40-12)
93% at 4 kW
240-430V /
9-16 V
Terminal
LV-Bus
AEGIS
(HEV2400)
82% at 2.4 kW
250-425 V/
13.8 V
CRCC
87% at 3.5 kW
220-475 V/
8-14.5 V
Auxiliary
Power Supply
Delphi
(90% at 2.2 kW)
216-422 V/
7-15.5 V
Texas
Instruments (1 kW)
200-400V/
9-13.5V
Terminal
HV-Bus
Power
MOSFETs
Water Cooler
(Bottom)
ETH Zurich
(93% at 2 kW)
240-450 V/
11-16 V
Kettering University
(93.2% at 2.5 kW)
220-400 V/
6.5-16 V
University of Tennessee
(96% at 6 kW)
250-450 V/
10-16V
Figure 15. Some APM products and research prototypes. (Sources: CRCC: Ahmed and Li; ETH: Krismer and Kolar; Kettering: Duan et al.;
Tennessee: Zhu et al.)
18
IEEE Electrification Magazine / JUNE 2021

IEEE Electrification - June 2021

Table of Contents for the Digital Edition of IEEE Electrification - June 2021