Opti-Maxx - Tie Line Controller Overview

Opti-Maxx is a suite of software modules specifically designed to minimize your total cost of electricity. Software programs are embedded directly into your facilities existing control system or may reside in a stand-alone computer connected via an OPC or Modbus interface.

Opti-Maxx continuously calculates your facilities marginal cost to generate electricity internally, based on fuel costs, boiler efficiencies, turbine efficiencies, condensing and venting costs.  Other variables, specific to your site, may be included, as required.

Your facilities internal marginal cost to generate power is continuously compared with the current market price, which is retrieved over the Internet.  Based on price differences, Opti-Maxx decides to either buy or make power.  Depending on your specific electrical contract, a decision to sell or shed electrical power may be included, if applicable.

Based on calculated decisions, Opti-Maxx software automatically drives condensing steam turbine generators to an optimum operating point while observing myriads of process constraints. Typical constraints include: emission limits, boiler limits, turbine and generator limits, contractual limits and more.

If economical, Opti-Maxx may even choose to vent steam to make additional power with non-condensing steam turbine generators.   If available, gas turbines may also be included in the overall optimization of electrical generation.

Unlike other systems that take several minutes to calculate the next move, Opti-Maxx software is quick. Every second, Opti-Maxx continuously captures opportunities to minimize overall energy costs by moving your process to the lowest cost solution. The result is incredible savings! Due to high fossil fuel prices, installation of Opti-Maxx usually pays for itself in only a few months.

A unique feature of Opti-Maxx is a text messaging system that informs Operators and Managers what is preventing the control software from doing better. Typical messages are, “Can't increase boiler load because ID fan is at maximum� or “Can't buy more power because turbine condensing load is minimized�.

Frequency distributions of system constraints are tabulated each day for performance analysis and reports. These reports easily identify and prioritize equipment improvements needed to increase savings even more. Using Opti-Maxx reports, improvement projects are quickly justified because returns on investment are easy to evaluate and assign.

In addition to Real-Time Pricing control, Opti-Maxx supports traditional interval demand tie-line control and instantaneous MW purchase control.  Depending on your facilities requirements, these additional controls may be included:

Interval Demand Megawatt Hour Purchase Control - In this mode, electrical power is purchased during your Power Company's demand  interval.   A pulse is received from the Power Company each interval to synchronize clocks.  Opti-Maxx control software monitors the Power Company's purchase meters and adjusts power generation, based on minutes left in the interval, the amount of electricity already purchased, the instantaneous MW purchase and the MW Target.   Opti-Maxx controller uses three different control strategies, depending on minutes left in the interval.  Opti-Maxx optimizes buying electricity to exactly reach the MW target at the end of the interval.  But, it also prevents process bumps across interval boundaries by matching instantaneous purchase megawatts to the target value.

Purchase Megawatt Control - In this mode, an instantaneous purchase MW target is maintained without regard to the Power Company's interval demand boundaries.  This mode is typically used during maintenance outages.

Load Shedding – Some facilities choose to implement our electrical load-shedding module to prevent setting new interval demand peaks or purchasing very expensive power. Smart decision making software insures only a minimum number of prioritized loads are shed to prevent penalties or minimize overall electrical cost.  Usually, load priorities are preset in tables but can be dynamically determined based on tank inventory levels and other factors.

Conclusion - Responding correctly to real-time pricing signals can reduce overall electrical costs, significantly. Many companies across North America are enjoying incredible energy savings with Opti-Maxx process control software.  Soon, you will too!