High power drive systems for electric motors are a key component of industrial automation and robotic systems as they account for more than half of electrical energy consumed. Such drive systems have a central function in achieving energy savings.
The increasing pace of automation places the motor drive system at the heart of the future industry. Increased efficiency and reliability at higher powers will continue to be a focus of industrial drive solutions.
The benefits of inverterized motor drives include:
- Better efficiency when running at full speed
- Further efficiency gains as they can run at lower speeds when required
There are different ways to partition a motor drive system. Intelligent power modules (IPMs) include the inverter and internal drivers in a single module. Power integrated modules include the inverter converter and brake circuits, usually without drivers. The reason for this is that for three-phase AC input applications, intelligent power modules become very large.
Let’s have a look at a module without drivers:
The pins of the module need to be spaced a certain distance apart from each other for
- Safety
- Long term reliability
These distances must be calculated for each application based on factors such as the maximum operating altitude of the drive, the effective voltages in the system, the isolation used in the system, pollution degree and CTI of the module and printed circuit board.
The detailed calculation for a typical motor drive application comes up with a minimum module dimension of around 70mm. Adding the spaces for the gate drive control pins makes the minimum module dimension even larger.
For low power industrial three-phase AC input applications, b