DC/DC Converter Discrete Control for Delay-Compensated Voltage Switching
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Solution Overview
Problem
Existing DC/DC converters face challenges in achieving fast and stable High/Low pulse operations due to delay times in voltage transitions, leading to unstable plasma generation and uneven thin film formation, particularly in high-frequency power applications.
Innovation Solution
A discrete control method is implemented in the DC/DC converter, compensating for delay times by modeling the main circuit and using a pulse width ΔT(k) with a parameter of delay time Td, incorporating AC current sensors, and employing single-phase or multi-phase interleaving control to suppress the influence of delay times during voltage switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PI control with double closed loop is used, then control stability is improved, but control response speed deteriorates due to dead time and frequency limitations
Solution Approach 1:
The patent replaces the traditional PI control mechanism with a discrete control mechanism that uses digital computation and delay time compensation. The control unit computes a pulse width ΔT(k) incorporating delay time Td as a parameter, substituting the continuous analog PI control with a discrete digital control approach that can achieve faster response without the frequency limitations of traditional PI control
Solution Approach 2:
The patent applies preliminary action by pre-calculating and compensating for delay time in the control algorithm. The delay time Td is incorporated as a parameter in the pulse width computation before the control action is executed, allowing the system to anticipate and compensate for the inherent delays in the control loop, thereby achieving faster effective response
2Speed
If switching frequency is increased to achieve fast transition, then control response speed is improved, but device complexity increases and control becomes complicated
Solution Approach 1:
The patent changes the control approach by introducing delay time Td as an explicit parameter in the pulse width computation. Instead of increasing switching frequency to achieve fast transition, the system uses discrete control with delay compensation that can achieve fast transition at moderate switching frequencies, thereby reducing control complexity while maintaining speed performance
3Ease of operation
If delay time is not compensated, then control simplicity is maintained, but manufacturing precision deteriorates due to unstable plasma and uneven thin film formation
Solution Approach 1:
The patent introduces delay time compensation as an intermediary element between the control command and the actual switching action. The control unit computes pulse width ΔT(k) that includes delay time Td as a compensating parameter, acting as a mediator that corrects for the inherent delays in the control loop, thereby ensuring precise control and uniform thin film formation without significantly complicating the control structure
Data Source
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AI summary
The present invention suppresses influence of control due to the delay time in voltage switching between a plurality of different voltages. A DC/DC converter comprises: a main circuit including a switching circuit; a control unit that performs discrete control by discrete control toward a command value; and a switching signal generation unit that generates a switching signal that drives the switching circuit. The control unit calculates the pulse width ΔT(k) of the switching signal having the delay time Td as a parameter as an operation amount of discrete control performed every control period Ts. The switching signal generation unit generates a switching signal based on the pulse width ΔT(k) obtained by the calculation in the control unit. The main circuit switches the voltage level by driving the switching circuit based on the switching signal of the switching signal generation unit.