Using Modbus to Communicate with Multiple OZpcs-RS40s

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 […]

Frequency/Watt Smart Inverter Functionality

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 […]

Volt/VAR Smart Inverter Functionality

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 […]

Anatomy of a Grid Tie Inverter

This post is first in a series discussing the subsystems and key components that go into a grid-tie inverter (GTI), and design considerations for the development of a practical commercial system. The majority of topics will apply equally to active front-ends (AFEs), and active rectifiers (more on the subtle differences between these two is covered […]

DC Link Requirements for Grid-Tie Inverters

A common question we field regarding grid-tie inverters goes something like “Can I interface to a 480V grid with a 680V DC-Link?”. To answer this question, lets consider a typical Grid Tie Inverter or Active Front End application as illustrated in the figure below. Generally, our application code uses center-aligned, space vector pulse width modulation […]