Hierarchical Transactive Energy Management System

Technology Overview

Hierarchical Transactive Energy Management System (HTEMS) is proposed not only to promote purchase/sale of energy transactions but also to solve the intermittency and variability of renewable energy sources (RESs) when they are integrated as part of the utility grid. A power hardware-in-the-loop (PHIL) platform is developed to test out the hardware controllers and converter design via the 4-quadrant three-phaser power amplifiers and to enhance the research capabilities for the smart grid technologies.

A low-cost transformer-less flexible power quality conditioner (FPQC) is invented to solve the power quality (PQ) problems of power systems due to the increasing usage of power converters. A series of multiport converters are developed to facilitate the integration of RESs into the power grid with the least number of components and acceptable cost.

Technology Features & Specifications

Based on an effectiveness studies conducted on the aggregated battery energy storage system (BESS) for frequency regulation, a 5-15% BESS penetration rate is recommended for the grid with the integration of intermittent RESs. The HTEMS system utilizing load frequency control (LFC) based on the model predictive control (MPC) approach is proposed to ensure that frequency deviations settle down to the steady-state nominal frequency much faster than the proportional-integral (PI)-based LFC.

Additionally, a hierarchical two-layer energy management system is proposed for controlling the aggregated and individual BESS, as well as improving the cost-effectiveness of BESS in the performance-based regulation market. An intelligent decision-support tool is introduced for optimal generation bidding of the generation and load aggregator, and for facilitating the participation of loads in the demand response market.

Features of the various components in the HTEMS system:

1) Hardware-in-the-loop (HIL) Platform:

  • Comprises real-time digital simulator, controllers, power amplifiers and the hardware devices for testing
  • Can be utilised for power HIL and control HIL studies on the power system or microgrid
  • Reconfigurable feature of components in the platform allows for rapid prototyping, shortening the time of testing and reducing the cost of development

2) Transformer-less FPQC:

  • Introduce the appropriate voltage and current compensation to mitigate power quality problems, without the need of transformer and DC source

3) Multiport Converter:

  • Provide multiple input and output terminals using less passive components
  • Enable the integration of RESs in the power grid using a shared converter

Potential Applications

The proposed technology can be applied in the energy industry:

  • MPC-based LFC algorithm can be implemented to arrest the frequency variations of the power grid with better performance results than those of the state-of-art PI-based LFC algorithm
  • Transformer-less FPQC can be commercialised to replace the conventional unified power quality conditioner with the objective of reducing the investment cost
  • Multiport converter can be commercialised to achieve the integration of the increasing RESs while reducing the cost of converter system

Customer Benefits

  • The proposed HTEMS improves the cost-effectiveness for the multi-usage of BESS aggregation
  • Compared with the conventional PI-based LFC, the proposed MPC-based LFC can stabilize the system frequency in a shorter time period. The settling time is improved from 23s to 12s during the case studies when load changes are introduced
  • The operation cost of the multiple interconnected microgrids can be reduced under different case studies using the proposed secure distributed transactive energy management system and MPC-based controller
  • The profit of the generation aggregator can be increased using the intelligent decision-support tool for optimal generation bidding
  • By replacing the unified power quality conditioner with the proposed transformer-less FPQC, the cost for solving the power quality problems can be significantly reduced

Make an Enquiry