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Smart Grid Dynamic Power Clamping (Computer & Electrical Engineering) Solution

Problem Overview

We evaluate the continuity parameter kk for the dynamic power transfer function:

P(I)={I2−16I−4:I≠4kI−2:I=4P(I) = \begin{cases} \frac{I^2 - 16}{I - 4} & : I \neq 4 \\ k I - 2 & : I = 4 \end{cases}
to ensure continuity across the calibration threshold I=4 AI = 4\text{ A}.


Step-by-Step Mathematical Solution

Step 1: Evaluate the limit as I→4I \to 4

Direct substitution of I=4I = 4 into the open rational branch yields 42−164−4=00\frac{4^2 - 16}{4 - 4} = \frac{0}{0} (indeterminate form).

Resolve the indeterminate form by factoring the difference of squares in the numerator (see Factor and Cancel):

lim⁡I→4I2−16I−4=lim⁡I→4(I−4)(I+4)I−4\lim_{I \to 4} \frac{I^2 - 16}{I - 4} = \lim_{I \to 4} \frac{(I - 4)(I + 4)}{I - 4}

For all I≠4I \neq 4, cancel the shared zero factor (I−4)(I - 4):

lim⁡I→4(I+4)=4+4=8 kW\lim_{I \to 4} (I + 4) = 4 + 4 = 8\text{ kW}

Step 2: Evaluate the defined function value at I=4I = 4

From the point definition branch at I=4I = 4:

P(4)=k(4)−2=4k−2P(4) = k(4) - 2 = 4k - 2

Step 3: Enforce Condition 3 of the Continuity Rubric

For P(I)P(I) to be continuous at I=4I = 4, the approached limit must equal the assigned point value:

lim⁡I→4P(I)=P(4)\lim_{I \to 4} P(I) = P(4)
8=4k−28 = 4k - 2
10=4k  ⟹  k=104=2.510 = 4k \implies k = \frac{10}{4} = 2.5


Engineering Conclusion

Setting the microcontroller gain parameter to k=2.5k = 2.5 forces the assigned power value P(4)=4(2.5)−2=8 kWP(4) = 4(2.5) - 2 = 8\text{ kW} to match the limiting power trajectory exactly. This eliminates the removable discontinuity (hole) at I=4 AI = 4\text{ A}, ensuring smooth, uninterrupted power delivery and preventing false-positive circuit breaker trips caused by computational glitches.