[Paper Review] On the Impact of Wireless Jamming on the Distributed Secondary Microgrid Control

Pietro Danzi, Čedomir Stefanović+3 more|arXiv (Cornell University)|Sep 22, 2016

Smart Grid Security and Resilience4 citations

TL;DR

This paper demonstrates that wireless jamming can severely disrupt distributed secondary control in DC microgrids by targeting just a few units, causing voltage restoration failure despite consensus algorithms. Using Wi-Fi-based communication, a simple periodic jamming attack on a subset of distributed generators leads to significant steady-state voltage errors (up to 10% with 1.3% probability), undermining grid stability. The study proposes modified access scheduling and highlights the need for anti-jamming and fault-tolerant consensus mechanisms to ensure resilience.

ABSTRACT

The secondary control in direct current microgrids (MGs) is used to restore the voltage deviations caused by the primary droop control, where the latter is implemented locally in each distributed generator and reacts to load variations. Numerous recent works propose to implement the secondary control in a distributed fashion, relying on a communication system to achieve consensus among MG units. This paper shows that, if the system is not designed to cope with adversary communication impairments, then a malicious attacker can apply a simple jamming of a few units of the MG and thus compromise the secondary MG control. Compared to other denial-of-service attacks that are oriented against the tertiary control, such as economic dispatch, the attack on the secondary control presented here can be more severe, as it disrupts the basic functionality of the MG.

Motivation & Objective

• To investigate the vulnerability of distributed secondary control in DC microgrids to wireless jamming attacks.
• To analyze the impact of simple, targeted jamming on voltage restoration and consensus convergence in wireless-enabled microgrids.
• To evaluate the effectiveness of existing countermeasures and propose improved strategies for maintaining system stability under jamming.
• To highlight the critical risk of jamming attacks on low-level control functions, which can destabilize the entire microgrid.
• To motivate future research on robust, anti-jamming secondary control schemes for resilient microgrid operation.

Proposed method

• Modeling a DC microgrid with six distributed generators (DGs) using droop-based primary control and PI-based secondary control to restore voltage deviations.
• Implementing a consensus algorithm over a Wi-Fi-based communication network to estimate average current and voltage for secondary control.
• Introducing a jammer that exploits periodic communication patterns, selectively disrupting only a subset of DGs using a periodic jamming strategy.
• Modifying the access duty cycle (T_AD) by dividing the consensus interval into N time slots, assigning each DG a unique transmission window to reduce collision probability.
• Using PLECS-based simulation to evaluate voltage and current dynamics under normal and jammed conditions, measuring steady-state error and convergence behavior.
• Evaluating the performance of the modified access scheme and comparing it with baseline scenarios to assess improvement in voltage accuracy.

Experimental results

Research questions

• RQ1 How does targeted wireless jamming affect the convergence and accuracy of consensus-based secondary control in a DC microgrid?
• RQ2 What is the impact of a simple, periodic jamming attack on a subset of DGs on voltage restoration and power sharing?
• RQ3 Can modifying the access scheduling in the consensus protocol reduce the probability of successful jamming?
• RQ4 What are the limitations of basic access scheduling as a countermeasure against intelligent jamming in microgrid control systems?
• RQ5 How can fault-tolerant consensus and anti-jamming techniques be integrated into secondary control to ensure microgrid stability?

Key findings

• A simple periodic jamming attack on just a few DGs causes significant voltage restoration failure, with steady-state voltage error exceeding 5% with a probability of 8.9%.
• The probability of a voltage error greater than 10% reaches 1.3% under jamming, indicating a high risk of instability during load changes.
• Even with equal power sharing maintained, the grid voltage stabilizes at 52.25 V instead of the target 48 V, resulting in an 8.85% error in the baseline scenario.
• The proposed access scheduling modification (T_AD_i = (i-1)*T_e/N) reduces the probability of >5% error to 5.1% and >10% error to 0.1%, showing modest improvement.
• Despite improvements, the access scheduling approach alone is insufficient for robustness, highlighting the need for advanced anti-jamming and fault-tolerant consensus techniques.
• The study confirms that jamming attacks on secondary control are more severe than tertiary control attacks, as they compromise the fundamental voltage regulation function of the microgrid.