||NAVSO P-3641A: More Power For The Dollar
Appendix B. Design Review Checklists
for Power Systems and Power Supplies
Sample Design Review Checklist for Power Systems
- Have critical system parameters been identified and prioritized?
- Has or will a system power architecture optimization be performed?
- Are the results of the System Architecture Study sufficiently
documented such that meaningful reference can be made during the actual system
- Does the power supply specification reflect optimized
- Does the method of distribution complement the system
- Is the prime power AC or DC?
- If the distribution is ac:
a. What is the frequency range?
b. Is it three-phase or
c. Is bus switching involved?
- If the distribution is DC:
a. Is bus switching involved?
distributed energy storage required?
- Common to both AC and DC:
a. What is the load power level?
b. What are the load
c. Are cable power losses and voltage drop
d. What is the cable impedance versus frequency?
accurate modeling, can it be a lumped parameter or must it be distributed?
Does the cable impedance overwhelm the source
e. Are the
distribution cabling, junction boxes, or any other hardware elements subject to
any EMI/EMC/EMP requirements?
f. What types of protection devices are
- How is platform and system coordination
safety issues are involved?
h. What level of shielding is required?
- How are shields terminated?
i. How is grounding
j. Are cables treated as emitters and susceptors,
and are adequate separation and shielding provided?
PRIME POWER SOURCE
- Have all power source impedance parameters (magnitude and phase) been
defined under all operating conditions? This should include the transient
and sub-transient reactance of generators as appropriate.
- Has system stability at the power source/system interface been
- Are hold-up requirements realistic?
- Have critical system loads requiring hold-up been segregated from the total
- When applicable, are MIL-STD-1399 Section 300 spike test requirements realistic with regard to specified source impedance (0.2 ohms)
- Are power source line voltage drops, as specified in the applicable power
source specification, realistic when considering the particular
- Are power supply performance requirements during abnormal power source
conditions sufficiently specified?
- Are inrush current limits realistically specified?
- Are there reactive elements within the power
distribution network in excess of those detailed in the power supply
- Have the requirements of MIL-STD-461 been realistically tailored to
the power supply?
- Have the power supply external interfaces been defined as complex
impedances? Have common mode specifications been adequately imposed on
the power supply?
- Does the specification provide sufficient details of system grounding
- Will a simulation model be adhered to during the initial design phase of
- Are power supply output ripple specifications consistent with ENfl
MONITORING AND CONTROL
- Are the monitoring and control requirements realistically specified
with regard to the required features to be implemented internal to the power
- Are monitoring and control limits sufficiently wide to allow for adequate
hysteresis for limit detectors and on/off functions?
- Is the monitoring specified to avoid false indications during start-up
- Have the EMI requirements with regard to monitoring and control
interface cables been sufficiently specified?
- Does the I/0 for the power supply provide for adequate separation between
the monitor, control, and power lines?
- Are the power supply environmental specifications tailored with regard to
the overall system environmental requirements?
SPECIFYING LOAD POWER
- Has stability at the interface between the power supply and its load
- Have the load impedances (magnitude and phase) been defined to support
- Has the total load power been defined including the conditions under
which it applies?
- Do the loads occur coincidentally or in sequence?
- Do the minimum load specifications take into account sub-system
- Is the power supply required to operate continuously or intermittently
up to the specified overload trip point?
- Is the power supply required to latch or provide smooth recovery after
removal of an overload condition?
- Are the interconnect wiring and connector pins adequately rated for
worst-case load conditions and voltage drop?
- Has the effect of load loss regulation been taken into account?
- Have the allowable peak power demands during tum-on been sufficiently
- When pulsed loads exist has the current amplitude and time related
pulse shape characteristic been specified?
- Has the allowable degree of voltage deviation and recovery response time
during a pulsed
load event been
- Has the power supply specification for protection taken into consideration
fault related conditions associated with the input power source, the power
supply and the load?
- Have the interface wiring and connector pins been adequately derated for
worst case fault conditions?
- Have the recovery features for the power supply after an overload or short
circuit removal been adequately specified?
- Has overload protection taken into account peak transient currents
during turn on?
- Have protection features been considered to protect the power supply
from over/under voltage conditions and reverse polarity conditions?
- Is the power supply adequately protected from over temperature
- Is the power supply protected from an external load-to-load short?
- Is the power supply protected from open/short remote sense leads?
- Will the parallel connected power supplies adequately share
- For multi-phase inputs will the power supply remain safe with loss of
one or more phases?
- Are ganged circuit breakers used for multi-phase power sources?
- Will the power supply operate continuously up to the
specified overload trip point?
- Has a system level test plan been
- Does the power supply specification adequately address system level related
test parameters that need to be considered during the power supply
- Are there sufficient test nodes available such that
test anomalies can be isolated at the system test level?