• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.914-915
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• 2008

Generally, inverter controller for UPS or renewable energy system have been used double loop PI controller, But it is hard to get controller gains for double loop controller because it is high order. Futhermore, to consider time specification is difficult too. This paper presents the way how to make double PI loop controller for inverter satisfied with time specification using CRA method and verify efficiency of it using Matlab and Psim.

• 전력전자학회논문지
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• 제8권2호
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• pp.116-127
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• 2003

본 논문에서는 UPS 인버터의 성능 개선을 위하여 출력측 LC 필터의 커패시터 전압과 전류의 2중 제어루프를 구성하고, 2중 제어루프에 디지털 제어시스템을 채택하였다 또한, 디지털 제어기의 연산지연시간을 보상하기 위하여 이러한 연산지연시간을 인버터 플랜트의 고유한 파라미터로 가정하고, 플랜트 모델에 포함시켜 모델링 하였다. UPS 인버터 출련전압의 과도상태 응답특실을 개선하고, 파라미터 변동에 강인한 특성을 얻기 위하여 2중 제어루프에서 내부 전류 제어루프는 내부 모델 제어기를 제안하였다. UPS 인버터 출력전압의 0의 정상상태 오차를 얻기 위하여 외부 전압 제어루프는 비례 제어기와 공진 제어기를 병렬로 연결한 비례-공진 진압제어기를 제안하였다.

• 전력전자학회논문지
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• 제25권6호
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• pp.442-450
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• 2020

A small-signal modeling approach for a three-level boost (TLB) converter and a design methodology for a double-loop controller are proposed in this study. Conventional modeling of TLB converters involves three state variables. Moreover, TLB converters have two operation modes depending on the duty ratio. Consequently, complex mathematical calculations are required for controller design. This study proposes a simple system modeling method that uses two state variables, unlike previous methods that require three state variables. Analysis shows that the transfer functions of the two operation modes can be expressed as identical equations. This condition means that the linear feedback controller can be applied to all operational ranges, that is, for full duty ratios. The design method for a double-loop controller using a PI controller is presented in step-by-step sequences. Simulation and experimental verifications are conducted to verify the effectiveness of the small-signal analysis and control system design.

• 전력전자학회논문지
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• 제8권6호
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• pp.561-568
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• 2003

PWM 인버터의 출력전압을 제어하는 방식에는 2가지 제어기법이 있다. 첫 번째 방법은 전류제어기를 사용하여 출력전압을 제어하는 이중 제어루프를 갖는 제어방식이며, 두 번째 방법은 단일루프만으로서 출력전압을 제어하는 제어방식이다. 일반적으로 3상 PWM 인버터의 제어기는 각상 제어 PI제어기, 2상 정지좌표계 PI제어기, 동기 좌표계 PI제어기로 구성되며, 각상제어 PI제어기를 이용하여 3상의 독립된 출력측 전압 및 전류를 제어하도록 구성된다. 단일루프 전압제어기는 높은 출력 임피던스의 경우 이중제어루프 도다 더 낮은 성능을 나타내기만, 낮은 출력임피던스의 경우에는 또는 부하범위에서 좋은 제어성능을 나타낸다. 또한 시뮬레이션과 실험을 통하여 이를 검증하였다.

• Journal of Power Electronics
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• 제15권3호
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• pp.695-701
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• 2015

Uninterruptible Power Supplies (UPSs) can be largely divided into the passive-standby, line-interactive and double-conversion methods. This paper proposes a double-conversion UPS with a low cost and high performance. This single phase UPS uses a single-loop robust voltage controller and 1-switch voltage doubler strategy PFC. The proposed UPS is composed of a single phase PFC, a half-bridge inverter, a battery charger and a battery discharger. Finally, the validity of proposed UPS was verified by various experimental tests.

• 전기학회논문지
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• 제67권7호
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• pp.871-877
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• 2018

In this paper, we propose a triple nested PID control scheme for stable hovering of a quadrotor and propose a complementary filter based sensor fusion technique to improve the performance of attitude, altitude and velocity measurement. The triple nested controller has a structure in which a double nested attitude controller that has the angular velocity PD controller in inner loop and the angular PI controller in outer loop, is nested in a velocity control loop to enable stable hovering even in the case of disturbance. We also propose a sensor fusion technique by applying a complementary filter in order to reduce the noise and drift error included in the acceleration and gyro sensor and to measure the velocity by fusing image, gyro, and acceleration sensor. In order to verity the performance, we applied the proposed control and measurement scheme to hovering control of quadrotor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1743_1744
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• 2009

In this paper, we propose a double network control approach for linear systems. Generally, there are two network control system structures: the direct structure and the hierarchical structure. Here, the hierarchical structure consists of a main controller and a remote controller. The network delay of the structure only appears in the closed loop between the main controller and the remote system. However, the delay can exist between the remote controller and the actuator. Therefore, we design the double network system with delays between the main controller and the remote system, and the remote controller and the actuator. Finally, we carry out simulations on the linear system to illustrate the effectiveness of the proposed control method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.496-500
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• 2001

There are two ways in the output voltage control method in PWM inverter. One is the double loop voltage control composed of inner current control loop and outer voltage control loop. Because it shows fast response and low steady state error, utilized in many application. The Other is single loop voltage control method composed of voltage control loop only. It's characteristics shows lower performance in case of high output impedance than double loop voltage control. But in low output impedance, it shows good control performance in all load range than double loop control. In this paper, single loop voltage control rule and gain was developed analytically, and these were verified through computer simulation and experiment.

• 대한전기학회논문지:전력기술부문A
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• 제55권1호
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• pp.7-12
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• 2006

This paper proposes the new voltage event detection method using the weight factor of neural network and describes control system design for the DVR(Dynamic Voltage Restorer) consisted of a rectifier and series inverter applied to 22.9kV distribution system. As this method can express the fault level of each phase, we expect the proposed method can make up for disadvantage of synchronous detection method. Also, in this paper, the control system was designed using double deadbeat controller, As it has an inner current control loop and an outer voltage control loop, we can easily limit the current level during the transient intervals by using the current control loop. Simulation and experiment are performed to prove the analysis of the voltage event detection method and double deadbeat controller.

• 전자공학회논문지SC
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• 제44권1호
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• pp.1-11
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• 2007

본 논문에서는 UPS 인버터의 성능 개선을 위하여 출력측 LC 필터의 커패시터 전압과 전류의 2중 제어루프를 구성하고, 2중 제어루프에 디지털 제어시스템을 설계하였다. 또한, 디지털 제어기의 연산지연시간을 보상하기 위하여 이러한 연산지연시간을 인버터 플랜트의 고유한 파라미터로 가정하고, 플랜트 모델에 포함시켜 모델링 하였다. UPS 인버터 출력전압의 과도상태 응답특성을 개선하고, 파라미터 변동에 강인한 특성을 얻기 위하여 2중 제어루프에서 내부 전류 제어루프는 내부 모델 제어기를 제안하였다. UPS 인버터 출력전압의 0의 정상상태 오차를 얻기 위하여 외부 전압 제어루프는 비례 제어기와 공진 제어기를 병렬로 연결한 비례-공진 전압제어기를 제안하였다. 또한, 사용자에게 쉽게 UPS의 동작 상태를 표시하기 위하여 그래픽 사용자 인터페이스를 이용한 UPS의 모니터링 시스템을 구현하였다.