In the process of motor drive, the DC-DC converter plays a very important role in the reliability and safety of gate drive. In addition, for the stability of motor operation, wireless vibration sensors can also be used to detect abnormal operation of the motor in advance. This article will introduce the characteristics of Murata's DC-DC converter and wireless vibration sensor and their application in motor drive.
Provide reliability and safety of motor drive
When the motor is driven, a gate driver is needed to control the low power signal generated by the integrated circuit and drive the gates of power crystals (such as an IGBT/SiC or power MOSFET. The environmental conditions of these applications are quite challenging, and the immunity of power supply must be improved to ensure the reliability and safety required for gate drive applications, in which a DC-DC converter plays an important role.
Murata has introduced the MGJ series DC-DC converters in consideration of relevant application requirements. They are specially designed and tested to withstand high dv/dt and DC link conditions without measurable breakdown in the isolation barrier. Common application fields of Murata's DC-DC converter include motor drive/motion control, solar inverter, welding, medical pump controller, medical X-ray system, HVAC inverter system, high power AC-DC conversion, electrical powered transportation system, pump and valve control, etc.
Support diversified product lines with different specifications and requirements
The MGJ family of DC-DC converters has a wide range of products, and its important features will be described below.
The MGJ1 is a 1W surface mount gate drive DC-DC converter, with bipolar output voltages of optimized IGBT/SiC and MOSFET gate drivers, supporting 5V, 12V, 15V and 24V inputs, +15V/-9V, +15V/-5V and +19V/-5V outputs, recognized UL60950 safety specification certification to enhance insulation at 250Vrms working voltage, recognized ANSI/AAMI ES60601-1 certification to support 2 MOPP at 250Vrms working voltage, with continuous barrier withstand isolation of 3kVDC, isolation test voltage of 5.7kVDC, creepage and clearance distance of 9mm, ultra-low isolation capacitance of 3pF, which can work in the temperature range from -40℃ to +105℃.
The MGJ2 is a 2W through hole gate drive DC-DC converter, supporting 5V, 12V, 15V and 24V inputs, , +15V/-5V, +15V/-8.7 V, +20/-3.5 V and +20V/-5V outputs. Just recently added are +15V/-3V and +18V/2.5V. Continuous barrier withstand voltage is 2.4kVDC, and the isolation capacitance is 3pF (typical). With bipolar output voltages of optimized IGBT/SiC and MOSFET gate drivers, it recognized UL60950 certification, supporting reinforced insulation at 150Vrms working voltage and providing basic/supplementary insulation at 300Vrms working voltage. It also recognized ANSI/AAMI ES60601-1, supporting 1 MOPP at 300Vrms working voltage, and supporting 2 MOOP/1 MOPP at 200Vrms working voltage. The isolation test voltage is 5.2 kVDC, the creepage and clearance distance is 2mm, and the ultra-low isolation capacitance is typically 3pF. Characterized CMTI >200kV/µS It is packaged in SIP and can work in the temperature range from -40℃ to +100℃.
In addition, there is a new product called MGJ2 surface mount, which supports the bipolar output voltage of optimized IGBT/SiC and MOSFET gate drivers, has enhanced insulation, and will recognize UL60950 and ANSI/AAMI ES60601-1 certifications to support 5.7kVDC isolated test voltage, has ultra-low coupling capacitance to support 12V & 15V inputs, and +15V/-9V, +15V/-5V and +20V/-5V outputs. With unique partial discharge performance, it supports a continuous barrier withstand voltage of 3kVDC.
The MGJ3 is a 3W surface mount gate drive DC-DC converter, without optical isolator feedback, with configurable dual output for all gate drive applications, supporting 5V, 12V, and 24V inputs, and +15V/-5V, +15V/-10V and +20V/-5V outputs. Continuous barrier withstand voltage is 3kVDC, and the isolation capacitance is 15pF (typical), supporting the bipolar output voltage of optimized IGBT/SiC and MOSFET gate drivers. It recognizes UL60950 certification to reinforced insulation at 250Vrms working voltage, and recognizes ANSI/AAMI ES60601-1 certification to support 1 MOPP/2 MOOP at 250Vrms working voltage. The isolation test voltage is 5.2kVDC, creepage and clearance distance is 7mm, with characterized CMTI >100kV/μS. It can work in the temperature range from -40℃ to +105 ℃.
Multiple package formats meet different requirements
The SIP, DIP and low-profile versions of the MGJ6 is 6W surface mount gate drive DC-DC converter, supporting 5V, 12V, and 24V inputs, and +15V/-5V, +15V/-10V and +20V/-5V outputs. Continuous barrier withstand voltage is 3kVDC, and the isolation capacitance is 15pF (typical), supporting the bipolar output voltage of optimized IGBT/SiC and MOSFET gate drivers. It recognizes UL60950 certification to reinforced insulation at 250Vrms working voltage, and recognizes ANSI/AAMI ES60601-1 certification to support 1 MOPP/2 MOOP at 250Vrms working voltage. The isolation test voltage is 5.2kVDC, with characterized CMTI >100kV/μS. The low isolation capacitance is 15pF, and the creepage and clearance distance is 7mm or 8mm series dependent. It is provided with SIP, DIP and low-profile surface mount packages, which can work in the temperature range from -40℃ to +105℃.
Another half-bridge, full-bridge, and three-phase version of MGJ6 is a 6W surface-mounted gate drive DC-DC converter, supporting 2:1 wide input voltages of 5V, 12V and 24V, isolation capacitance of 15pF (typical), and bipolar output voltage of optimized IGBT/SiC and MOSFET gate drivers. Outputs can be configured using appropriate external Zener/resistor combinations. It recognizes UL60950 certification for reinforced insulation, and recognizes ANSI/AAMI ES60601-1 certification to support 2 MOPP at 250Vrms working voltage. Continuous barrier withstand is 3kVDC, isolation test voltage is 5.7kVDC, and with characterized CMTI >100kV/μS. With partial discharge performance, the low coupling capacitor is 15pF, and the creepage and clearance distance is 8mm.
There is also a 14mm MGJ6, which has no optical isolator feedback, supports bipolar output voltage of optimized IGBT/SiC and MOSFET gate drivers, with configurable dual output for all gate drive applications, including +15V/-5V, +15V/-10V and +20V/-5V outputs, and 5V, 12V and 24V input voltages. It recognizes UL60950 certification to reinforced insulation at 690Vrms working voltage, while it is still under IEC 61800-5-1 certification. Based on 690Vrms working voltage, the continuous barrier withstand is 3kVDC, with characterized CMTI >100kV/μS, with 14mm creepage and clearance distance. The typical value of isolation capacitance is 13pF, and can work in the temperature range from -40℃ to +105℃.
MGJ6D is a 6W surface mount gate drive DC-DC converter, supporting 12V input and +15V/-4V and +18V/-2.5V outputs. Continuous barrier withstand is 3kVDC, and the typical value of isolation capacitance is 13pF, supporting the bipolar output voltage optimized for Rohm/Wolfspeed and SiC gate drivers. It is under application for UL60950 certification, to reinforced insulation at 250Vrms working voltage, and under application for ANSI/AAMI ES60601-1 certification (to be determined) to support 1 MOPP/2 MOOP at 250Vrms working voltage. The isolation test voltage is 5.7 kVDC, and it is available in SIP, DIP and low-profile surface mount packages. The creepage and clearance distance is 8mm, and it can work in the temperature range from -40℃ to +105℃.
Wireless sensing can reduce downtime losses
In a factory environment, it is often necessary to wait until the machine breaks down before one can know whether the machine is operating normally. At this time, the system is shut down and the production line suspended, which has great impact and loss to the production process and product delivery. If the abnormal state can be found in advance before the machine breaks down, we can respond as early as possible and reduce the impact caused by the shutdown.
Murata provides a series of wireless sensing solutions, which can provide sensor data and useful information, and can be used for predictive maintenance, energy saving and productivity improvement of factories and equipment. This is a change from Time-Based Monitoring (TBM) to Condition-Based Monitoring (CBM). By placing the wireless sensor on the existing equipment, the traditional mode of maintenance at fixed time is changed to the mode of maintenance in advance after the abnormal state of the machine is identified in time, which can reduce the unexpected downtime and stabilize the production quality.
Murata's wireless sensor solution is quite simple to install, and the system installation can be completed only by placing the wireless sensor node on the machine to be monitored. The system uses stable radio communication and repeaters sub-1 GHz, and can work in harsh environments such as steel mills.
This solution is scalable and flexible. Sensors can be added to the existing system at any time as necessary. API can also be used to develop its own visualization or maintenance solution to carry out unified data management and optimize the maintenance process based on collected sensor data.
Detection of abnormal motor vibration and early detection of problems
Taking Murata's LBAC0ZZ1LZ wireless vibration sensor unit as an example, it uses Murata's many years of expertise in piezoelectric ceramic materials to provide a wide range of measurement frequencies and longer battery life for the vibration sensor unit. It can be installed on rotating equipment such as pumps and fan motors, and abnormalities can be detected through vibration to improve the efficiency of equipment maintenance.
The size of the LBAC0ZZ1LZ wireless vibration sensor unit is only 38 x 24 x 38 mm, and the weight is only 50g (including battery). Using dedicated ISM radio communication interface sub-1GHz, and having been certified by region/country, it can measure peak acceleration, frequency of peak acceleration, acceleration RMS, kurtosis, temperature and other data. The absolute maximum rating can reach ±30G, and the resolution can reach 28mG. The detection frequency ranges from 12.5 Hz to 10,000Hz. The detection direction is Z axis. The operating temperature range is from -10℃ to 85 ℃. The resolution is 0.1℃@25℃. The measurement accuracy can reach ±3dB in vibration. The temperature is 1℃@25℃. The body (ambient) can operate at the temperature of -10℃ - 60℃ and RH of <90% (non-condensing), and the sensor can operate at the (surface) temperature of -10 ℃ - 85 ℃ and RH of <90% (non-condensing). It is IP65 compliant. Using a lithium thionyl chloride battery, it has an operating life of 5 years (reporting every 1 hour and operating environment at 25 ℃), and the measurement interval can be set to 15, 30 seconds, or 1, 5, 10, 15, 30 minutes, or 1, 2, 6, 12, 24 hours.
Disclaimer: All these products are certified in Japan, Thailand and Singapore only. For other countries/regions, please contact us for more details.
Conclusion
A DC-DC converter plays an important role in the stability of motor operation, while wireless vibration sensor can detect abnormal vibration of motor, so as to carry out early maintenance and reduce losses caused by shutdown. These solutions introduced by Murata will be of great help to improve the operating efficiency and stability of factory motors.