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Dave Zendzian

Recent Posts

Using Modbus to Communicate with Multiple OZpcs-RS40s

Posted by Dave Zendzian on Mar 3, 2021 8:43:13 AM

The OZpcs-RS40 is a 40kW Power Conversion System (PCS) intended for battery-based energy storage applications. The PCS is designed to be mounted in a standard 19” rack, and easily paralleled to scale power capability. All hardware interfaces are located on the front panel, utilizing pass-through type terminal blocks for simple daisy chained cable or bus bar power connections. Similarly, the Modbus and digital I/O signals are provided on redundant, high density, 15-pin D-Sub connectors, which also allow for simple daisy chain cabling. When using Modbus to control multiple, paralleled PCS there are several things to consider, including termination, addressing, and broadcast messaging.

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Topics: Grid Tie Inverter, Digital Power Control, energy storage, MODBUS, Smart Inverter, UL1741-SA

Frequency/Watt Smart Inverter Functionality

Posted by Dave Zendzian on Feb 1, 2021 12:02:05 PM

In a previous post, I discussed how the Volt/VAR function can be used to provide grid voltage stabilization during over and under-voltage conditions. In addition to stabilizing out of tolerance voltage conditions, over and under-frequency grid conditions can also be mitigated using Frequency/Watt functionality. In a manner similar to Volt/VAR, the Frequency/Watt function will automatically generate real power commands based on grid frequency measurements.

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Topics: Grid Tie Inverter, Digital Power Control, energy storage, Smart Inverter, UL1741-SA

Volt/VAR Smart Inverter Functionality

Posted by Dave Zendzian on Dec 23, 2020 4:41:47 PM

To support grid voltage stabilization during over and under-voltage conditions, UL1741 certified smart inverters, such as the OZpcs-RS40, can be configured to automatically absorb or inject reactive power based on grid voltage measurements. This behavior is commonly referred to as Volt/VAR control and is implemented using a configurable array of points, that when combined, define a linear, piece-wise curve that results in the desired Volt-VAR behavior.

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Topics: Grid Tie Inverter, Digital Power Control, energy storage

Back to Back Buck-Boost Converter

Posted by Dave Zendzian on Apr 3, 2018 9:32:20 AM

Through the proper configuration of two OZip-DC/DC Intelligent Power Modules, it is possible to transfer energy between two DC power sources with overlapping voltage ranges.  In this configuration the DC-DC Converters are connected “back-to-back” such that they share a common, intermediary rail voltage.  The following figure illustrates a “Back-to-Back” Buck-Boost DC/DC converter. 

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Topics: DC/DC Converters

A Second Generation Digital SCR Controller

Posted by Dave Zendzian on May 2, 2017 8:48:15 AM

The OZSCR2000 is our latest SCR Firing and Control board offering, built upon the successful OZSCR1000 digital control platform. This second generation controller uses a Texas Instruments Piccolo processor, and provides all the original digital control features, including:

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Topics: Digital Power Control, SCR Controller

What is MESA/SunSpec?

Posted by Dave Zendzian on Mar 31, 2017 1:26:20 PM

Traditionally, grid energy storage systems (ESS) have been one-off solutions, utilizing proprietary software and hardware components.  As such, each installation requires time consuming, custom integration.  Often times proprietary vendor hardware or software protocols require "hacks" to get all components to play nice.  Ultimately this approach results in higher costs, decreased reliability, and limited scalability and upgrade options.

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Topics: Grid Tie Inverter, power inverter, Power Conversion, energy storage, MODBUS

Grid Energy Storage for Emergency Preparedness

Posted by Dave Zendzian on Jul 16, 2014 10:30:00 AM

Energy_Storage_for_Emergency_Preparedness_

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Knowing Your Grid Forming Inverter

Posted by Dave Zendzian on Jun 5, 2014 8:30:00 AM

In remote locations where the traditional utility power grid is inaccessible, standalone microgrids, powered by renewable energies like solar and wind turbines, are playing a crucial role in generating electricity for the local community. In addition to generating power to meet the electricity needs of islands and remote communities across the world, microgrids also see application within conventional power grid locations by helping utilities in times of outages by delivering reliable power to neighborhoods, hospitals and mission critical buildings.

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Thermal management: the life of your power conversion system depends on it

Posted by Dave Zendzian on Jan 3, 2014 2:08:00 PM

There is no doubt that operating environment has a major effect on the life and reliability of electronic assemblies.  Power electronics in particular are perhaps most susceptible to life and reliability degradation, as there are usually several components within the system whose losses all conspire to raise the operating temperature.  Losses include switching and conduction losses in semiconductor devices as well as losses in passive components such as magnetics, filter damping resistors, and bus bars. 

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Topics: thermal management

Power Conversion Systems: Three manufacturing options

Posted by Dave Zendzian on Dec 12, 2013 8:27:00 AM

In our recent blog posts we’ve been discussing specifying and sourcing power electronics in order to help you better understand your needs as well as the various design and manufacturing options available to you. These options range from using an off-the-shelf power conversion system, to designing and building your own power conversion system in-house, or partnering with an outside vendor to handle some combination of custom engineering and product manufacturing.

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Topics: Power Conversion