Inverter Command Validation for Cyber-Secure Grid Control
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Solution Overview
Problem
Existing inverter control systems have limited computational resources for robust security mechanisms, are vulnerable to cyber threats due to complex communication technologies, and may violate regulations, especially when manufactured in foreign countries, leading to potential stability and safety issues in power generation and transmission.
Innovation Solution
An improved method and system for controlling inverters that includes an inverter control system capable of validating command messages by comparing communication parameters and inverter data with a predetermined model, detecting cyber-attacks, and generating control signals to prevent malicious commands, while also allowing for secure firmware updates and inverter replacement without grid interconnection model modification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing inverter control systems are used with complex communication technologies, then communication versatility is improved, but security vulnerability increases
Solution Approach 1:
The patent introduces an inverter control system as an intermediary layer between the communication network and the inverter. This control system validates command messages before execution, acting as a security mediator that prevents direct access to the inverter while maintaining communication versatility through multiple protocols.
Solution Approach 2:
The system implements feedback mechanisms where the inverter control system continuously monitors command messages and compares them against expected parameters. This feedback loop enables real-time detection of malicious commands while maintaining normal communication operations.
2Reliability
If inverter control systems implement robust security mechanisms, then security reliability is improved, but computational resource requirements increase
Solution Approach 1:
The patent applies partial action by implementing security validation only for critical command parameters rather than entire message validation. This approach provides sufficient security for control functions while minimizing computational overhead on resource-constrained inverter systems.
Solution Approach 2:
The security mechanism is segmented into separate validation functions that check specific parameters independently. This modular approach reduces computational complexity by avoiding comprehensive message validation while maintaining security for critical control parameters.
3Ease of manufacture
If inverter control systems are manufactured in foreign countries, then manufacturing cost is reduced, but regulatory compliance risk increases
Solution Approach 1:
The inverter control system serves as an intermediary that enforces regulatory compliance requirements regardless of manufacturing location. By implementing mandatory security validation and monitoring functions, the system ensures adherence to bulk-power system security regulations while allowing flexible manufacturing arrangements.
4Reliability
If command messages are validated by comparing with predetermined models, then security detection capability is improved, but processing time increases
Solution Approach 1:
The validation process applies partial action by checking only critical parameters against predetermined models rather than comprehensive message verification. This selective validation maintains high security detection capability for control commands while minimizing processing time overhead.
Solution Approach 2:
Different validation strictness levels are applied to different command types. Critical control parameters undergo rigorous model comparison, while non-critical parameters receive lighter validation. This local quality approach optimizes the balance between security detection and processing efficiency.
Data Source
AI summary
A method for controlling an inverter in an energy plant coupled to an electric power grid or operating in an islanded mode, the method comprising: using an inverter control system communicatively coupled to the inverter, receiving one or more command messages for controlling the inverter; determining whether a command message of the one or more command messages is legitimate by at least one of: comparing communications related parameters contained in the command message to predetermined legitimate communications related parameters; comparing value range related parameters contained in the command message to predetermined legitimate value ranges; comparing data received from the inverter with a predetermined functional model of the inverter; and, detecting power, current, or voltage oscillations at the inverter; if the command message is not legitimate, dropping the command message; and, if the command message is legitimate, generating one or more control signals to implement the command message and transmitting the one or more control signals to the inverter to control operation of the inverter.