Piezo driver

For PiezoElectric actuators in Aerospace, Oil & Gas, and Industrial applications

Category

Industrial Electronics
Power Electronics

SERVICES

Hardware engineering
Power electronics
Mechanical Design
Embedded Firmware
Web server

2019 - 2020

The Challenge

Piezo actuators are often used in applications that require precise control, fast response, and exceptional durability. Kinetic Ceramics is an industry leading producer of piezo elements and control systems whose products are used in Oil and Gas, Aerospace and Medical industries by NASA, KLA Tencor, and Exxon Mobile. Such applications demand that control system for piezoelectric actuator creates thousands of volts, operates with high bandwidth, and produce low EMI. AJProTech took a challenge to develop a reliable and versatile Piezo Driver system in a compact enclosure.

The Solution

Piezo actuators provide best performance and accuracy when driven by high frequency 1200V signal. Such systems typically use high voltage transformers that are bulky and limit performance. AJProtech and Kinetic Ceramics created PD-600 - integrated solution that boosts low voltage input to 1200V and generates up to 500W of power with full bridge MOSFET inverter. System may be controlled through embedded HTML User Interface by any Windows or Linux computer through Ethernet, USB, or RS-232 interface

AJProTech created a High Voltage Power Electronics with robust mechanical design, developed embedded firmware and HTML UI, and optimized design for low EMI

Spheres of application

Oil and Gas

Oil and Gas

Aerospace

Aerospace

Our approach

Kinetic Ceramics install Piezo Actuators systems in many mission-critical applications where reliability is the ultimate priority and end-users expect years of continuous operation without failures. Other priorities include higher performance and compact form-factor.

From inception of the project, we had to push the boundaries of Power electronics to achieve target performance. Project started with intense R&D and validating critical assumptions in Power Electronics, EMI reduction.

Modular system architecture in PD-600 was chosen to enable parallel workstream on Power Supply, Inverter module, Control Circuits. Modules can also be used in multiple products and easily replaced for service.

We used Agile iterative approach and designed production-ready device in 3 iterations of design and prototyping.

Product design

Industrial Electronics applications often use sheet metal enclosures because of high level of protection and low fixed startup expenses. Sheet metal is processed with laser cutting, CNC machine bending, and spot welding.

Metal enclosure was best choice for PD-600 to withstand mechanical impact, vibration, and shield EMI created by high-voltage power electronics circuits switching over a thousand volts, thousands of time per second.

Mechanical engineers at AJProTech created mechanical design that fit into standard 19” rack. Enclosures can be cost-effectively produced with quantities from few samples to several thousand units.

Power Electronics

Piezo actuators provide best performance and accuracy when driven by high frequency 1200V signal. Such systems typically use high voltage transformers that are bulky and limit performance. PD-600 was designed without bulky high voltage output transformers.

POWER SUPPLY: Low voltage 24VDC power input is boosted to generate 1500 Volts rail.

FULL BRIDGE INVERTER uses generates sin wave output with amplitude of 1200 volts using SiC MOSFETs. Silicon-Carbide components allow high-quality output wave due to low switching losses at high frequency.

POWER ELECTRONICS design went through extensive R&D to achieve reliable operation and reduce EMI created by high-voltage switching

Control module

At AJProTech, we have a proven process designing complex electronics hardware. Starting with system architecture and components selection, we reliably produce future-proof electrical designs.

Heart of the system is 32bit Cortex-M4 / Cortex-M0 MCU from NXP. Controller generates PWM commands for Power Amplifier, collects feedback from sensors (current, voltage, temperature, pressure), and provide essential safety functions.

Controller supports variety interfaces including 100MBit Ethernet, USB2.0, MODBUS / RS-485 interface, and Bluetooth.

Hardware design included PCB layout with multiple analog and digital circuits. 6 layer PCB with dedicated ground planes ensures no signal interference.

Web server

Our Embedded Software team designed embedded HTML server running on device MCU and accessible through 100Mbit Ethernet port.

Lightweight HTML server runs offline for local control but also supports remote access

User Interface for PD-600 allows full control of device operation including

  • ON/OFF
  • changing operation parameters (voltage, frequency, wave shape)
  • setting safety limits
  • reviewing log of events
  • updating device firmware

Firmware and Software development

PD-600 is built with robust automotive / industrial grade ARM 32bit microcontroller that runs both low-level software to control essential functionality (embedded firmware) and high-level software (User Interface).

We designed Embedded firmware for 32bit ARM Microcontroller with focus on reliability and efficiency. Bare-metal firmware is written in C++ without using RTOS to provide fast response time. Microcontroller receives data from temperature, voltage, current sensors; generates control PWM commands to actuator elements; and monitors abnormal conditions to execute immediate shutdown, if needed.

User interface is implemented as embedded HTML web server running directly on the microcontroller. Operator may use external Linux, Windows, and Mac devices to access controller. Device is also accessible via MODBUS and USB interface. Device firmware may be updated through web-interace by uploading new binary file

Our software engineers combined low-level and User Interface on a single microcontroller, implemented firmware update routines, and completed extensive tests and software validation

HOW IT WORKS

01.
Connect a supported piezo element to High voltage amplifier
02.
Device operation is controlled by a web interface, MODBUS, or USB connection to select desired amplitude and frequency
03.
Microcontroller generates control signals to Power electronics circuit and ensures safe operation
04.
24VDC power input is boosted to generate 1500 Volts DC Link.
05.
High voltage inverter generates sin wave output using SiC MOSFETs.

Mechanical design with EMI shielding

Metal enclosure was best choice for PD-600 to withstand mechanical impact, vibration, and shield EMI created by high-voltage power electronics circuits switching over a thousand volts, thousands of time per second.

Mechanical engineers at AJProTech created mechanical design that fit into standard 19” rack. Enclosures can be cost-effectively produced with quantities from few samples to several thousand units.

  • Noisy Power electronics circuits that produce substantial EMI are isolated from Control circuits
  • Each PCB is located in separate compartments isolated by grounded metal shields
  • Shielded cables are used to minimize cross-talk between subsystems
  • Sensitive systems are strategically split across several PCBs to minimize EMI effects

PROTOTYPING

When design files are complete and manufacturing drawings are prepared, it’s time to create pilot prototypes. We usually produce 5-10 samples and run them through series of tests

At AJProTech we have in-house equipment to assemble and test prototypes, fast and efficient. We use our wide network of vendors to rapidly prototype PCBAs, Metal enclosures, and custom electromagnetic components.

Enclosure is produced of sheet metal with laser cutting, CNC bending, welding, and powder painting.

Magnetic components are custom made to our specification.

PCBA are assembled on SMT line or manually

Assembly

In most cases, we produce and assemble pilot samples in 4-6 weeks. We leverage our industry connections to eliminate long lead times and ensure tight quality control, even at small volume.

PD-600 went through 3 iterations of design and prototyping to find optimal operation and EMI reduction. Each module was installed in isolated compartment with metal dividers to ensure best possible noise immunity.

Bring up and Validation

Each batch of prototypes goes through a series of tests with our engineering team to ensure stable operation under various operation conditions.

Kinetic Ceramics ran extensive tests to ensure PD-600 meet high standards of precise control and reliability that is expected of purpose-built industrial electronics.

Typical tests include

  • Low voltage operation
  • Full power operation
  • Long-term endurance testing
  • Corner cases with various parameters of voltage, frequency, and environmental conditions
  • Signal integrity review for high-frequency lines
  • EMI test

Device in operation

Video demonstrates PD-600 operation with various settings. Oscilloscope demonstrates changing high voltage output as operator changes desired parameters in web interface

  • Wave shape: sin wave or trapezoidal
  • Peak-to-Peak voltage: 0 - 1200 Vpp
  • Signal frequency: 0 - 1000 Hz
  • Slope, Duty cycle, Voltage offset

Product specification

Application Industrial, Oil and Gas, Aerospace, Medical
Dimensions 10 x 9 x 4 in / 25.4 x 22.9 x 10.2 cm
Components Power Supply, Controller, Amplifier
Power input 24VDC
Power output 600W, 1200Vp-p, Sin-Wave
Connectivity Ethernet, USB2.0 , ModBus (RS-485), Bluetooth
Controls 32bit ARM Microcontroller with HTML User Interface and Remote Access
Sensors
  • Inlet/Outlet Pressure
  • Flow Rate
  • Fluid Temperature
  • Ambient Temperature
  • Piezo Temperature

Impact

Kinetic Ceramics added new Piezo Driver to their line of state-of-the-art product selection of high voltage amplifiers that optimally drive Piezomotor-powered systems to achieve extreme precision and instantaneous response. Innovative drivers and systems allow manufacturers to satisfy complex production requirements with a wide range of achievable flow rates and pressures, creating new opportunities for decreased costs and expanded product offerings.

Product page

Kinetic Ceramics helped solve some of the toughest problems across a wide range of industries through the innovative application of piezo actuators. From Aerospace to Oil & Gas, and everywhere in between, they’ve helped companies like KLA Tencor, NASA, DARPA, Exxon Mobile, and others

Product page

Download this case study

Get a PDF version of case study to download and share.

Contact us

United States
Headquarters Los Angeles, CA 9410 Owensmouth Ave, Chatsworth, CA 91311
Taiwan
R&D and Manufacturing New Taipei City 120 Nan Shi St.  
Kazakhstan
Software design Almaty