The Hitachi LH1 series frequency converter is a multi-purpose, universal vector type frequency converter that integrates energy saving, high efficiency, and flexibility. It inherits the excellent genes of Hitachi inverters in the field of drive control, aiming to contribute to the construction of an environmentally friendly society. The LH1 series is not only compatible with the drive of asynchronous motors (IM) and permanent magnet synchronous motors (PM), fully realizing the energy-saving potential of motors, but also achieves "smooth and stable" operating performance through various anti-interference measures and rich application functions. Its product design fully considers the convenience of users, from flexible installation methods to convenient communication wiring, to a variety of optional operators, all reflecting the unremitting pursuit of "simplicity and ease of use".
The driving force of "smoothness and stability": the cornerstone for dealing with complex working conditions
The core advantage of the LH1 series lies in its strong anti-interference ability, ensuring that the motor can operate smoothly and stably under various harsh working conditions.
2.1 Low voltage ride through (instant stop ignore) function
This is a reliable solution provided by the LH1 series to solve the problem of unstable power grids. When the power supply voltage drops, interrupts or loses power instantly, the frequency converter can use the inertia energy of the motor to maintain continuous operation of the equipment. After the power supply is restored, the system automatically returns to normal. This function can effectively ensure the continuity and safety of production in situations where multiple motors are running synchronously or the power grid conditions are poor, especially suitable for large inertia loads such as wind turbines.
2.2 Overcurrent and Overvoltage Suppression Function
The LH1 series is equipped with a high-speed CPU that can detect and process instantaneous overcurrent or overvoltage caused by rapid acceleration, deceleration, and impact loads. It automatically optimizes operating speed, strongly suppresses current and voltage, avoids frequent tripping, achieves strong continuous stable operation, and protects mechanical equipment from impact.
2.3 Optimization Control of Large Inertial Load
For large inertia loads such as fans, the LH1 series provides specialized solutions:
Start the "windproof car": effectively avoiding the problem of the motor not starting properly due to the rotation of the wind blades under the action of airflow (windmill phenomenon).
Parking "rear excitation": Apply excitation during shutdown to achieve fast, efficient, and accurate positioning and parking, improving production efficiency.
Overexcitation rapid stopping: By increasing the excitation of the motor to increase losses, rapid stopping can be achieved without the need for external braking resistors, effectively reducing system costs. It is particularly suitable for situations such as fans and centrifuges that require rapid braking.
Low carbon and efficient energy-saving: the core driving force for the future
The LH1 series has outstanding performance in energy conservation and consumption reduction, maximizing the operating efficiency of the motor through various technological means.
3.1 Compatible with permanent magnet synchronous motor (PM) drive
The LH1 series is seamlessly compatible with asynchronous motor (IM) and permanent magnet synchronous motor (PM) drives. By utilizing the high efficiency characteristics of PM motors, the overall energy efficiency of the system can be significantly improved, achieving a "one in one" drive platform that helps reduce inventory, spare machines, and lower costs.
3.2 High frequency operation and energy-saving mode
Broadband operating range: The output frequency can be smoothly adjusted within the range of 0~590Hz, with a maximum of 590Hz, meeting the requirements of high-speed and high-precision applications such as precision machining.
Energy saving operation mode: Especially suitable for fans and pumps that operate continuously for a long time. This mode adopts Hitachi's unique "U-finding algorithm", which can automatically track the optimal energy-saving working point of the motor, adjust the output voltage and current in real time, maximize the operating efficiency of the asynchronous motor, and achieve energy saving and consumption reduction.

The flexibility of "flexibility and diversity": meeting diverse applications
The LH1 series meets the complex application needs of various fields through rich built-in functions and flexible configuration options.
4.1 Programmable (EzSQ) Functionality
The LH1 series is equipped with powerful EzSQ programmable functionality. Users can customize their functions by creating specialized process programs. This helps simplify the upper device and surrounding circuits, save control cabinet space, and reduce costs. Its performance parameters include: