비례유량제어밸브 위치제어기 자동조정

정규홍(Gyu Hong Jung) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.7

비례솔레노이드밸브는 코일전류에 비례하는 전자기력을 이용하여 밸브 변위를 연속적으로 가변시키는 밸브이다. 대용량 비례유량제어밸브는 발전소나 화학 플랜트에서 물, 스팀, 가스 등과 같은 공정유체의 대용량 유량제어에 사용되며 공압이나 모터를 이용하는 밸브에 비하여 우수한 응답성능과 소형화의 장점을 가진다. 본 연구에서는 비례제어밸브를 대상으로 밸브의 동적 특성을 식별한 후 목표 성능이 만족되도록 위치제어기의 비례적분이득을 자동으로 조정하는 기능을 설계하였다. 동특성 식별은 릴레이피드백을 통하여 한계 안정 상태에서의 임계이득과 임계주기로 파악하였으며, 비례적분이득 결정에는 Ziegler-Nichols 방법을 적용하였다. 구현된 기능은 시험을 통하여 성능을 검증하였으며 밸브 작동점과 릴레이 제어기 변수가 자동조정에 미치는 영향을 분석하였다. Proportional solenoid valves are a modulating type that can control the displacement of valves continuously by means of electromagnetic forces proportional to the solenoid coil current. Because the solenoid-type modulating valves have the advantages of fast response and compact design over air-operated or motor-operated valves, they have been gaining acceptance in chemical and power plants to control the flow of fluids such as water, steam, and gas. This paper deals with the auto tuning of the position controller that can provide the proportional and integral gain automatically based on the dynamic system identification. The process characteristics of the solenoid valve are estimated with critical gain and critical period at a stability limit based on implemented relay feedback, and the controller parameters are determined by the classical Ziegler-Nichols design method. The auto-tuning algorithm was verified with experiments, and the effects of the operating point at which the relay control is activated as well as the relay amplitude were investigated.

비례적분+이중적분 제어기를 이용한 정상상태 응답 개선

정규홍(Gyu Hong Jung) 유공압건설기계학회 2016 유공압건설기계학회 학술대회논문집 Vol.2016 No.11

The performance characteristics of a dynamic control system are evaluated according to the transient and steady-state responses. The transient performance is the controllability of the output for the tracking of the reference or the ability to reduce or reject the effects of unwanted disturbances; alternatively, the steady-state performance is represented by the magnitude of the control error at the steady state. As the effects of the two performances on each other are reciprocal, a controller design that shows a zero steady-state error for the ramp input is uncommon because of the challenge regarding the achievement of an acceptable transient response. This paper proposes a PI+double-integral controller for the elimination of the steady-state error for the ramp input while a sound transient performance is maintained. The control-gain design procedure is described by the second-order response for the step input and the response of the error dynamics for the ramp input. The PI+double-integral controller is designed for the first-order transfer function that is derived from a system identification with the open-loop experiment data of the dc-motor. The simple structure of the proposed controller enables the adoption of a low-end microcontroller for the implementation of a real-time control. The experiment results show that the control performance is as effective as that of the simulation analysis for the operating point of linear system; furthermore, the PI+double-integral controller can be conveniently applied to the control system, which is desirable for the improvement of the steady-state error.

비례적분+이중적분 제어기를 이용한 정상상태 응답 개선

정규홍(Gyu Hong Jung) 유공압건설기계학회 2016 드라이브·컨트롤 Vol.13 No.3

The performance characteristics of a dynamic control system are evaluated according to the transient and steady-state responses. The transient performance is the controllability of the output for the tracking of the reference or the ability to reduce or reject the effects of unwanted disturbances; alternatively, the steady-state performance is represented by the magnitude of the control error at the steady state. As the effects of the two performances on each other are reciprocal, a controller design that shows a zero steady-state error for the ramp input is uncommon because of the challenge regarding the achievement of an acceptable transient response. This paper proposes a PI+double-integral controller for the elimination of the steady-state error for the ramp input while a sound transient performance is maintained. The control-gain design procedure is described by the second-order response for the step input and the response of the error dynamics for the ramp input. The PI+double-integral controller is designed for the first-order transfer function that is derived from a system identification with the open-loop experiment data of the dc-motor. The simple structure of the proposed controller enables the adoption of a low-end microcontroller for the implementation of a real-time control. The experiment results show that the control performance is as effective as that of the simulation analysis for the operating point of linear system; furthermore, the PI+double-integral controller can be conveniently applied to the control system, which is desirable for the improvement of the steady-state error.

OWC 파력발전용 전력변환장치의 빠른 동특성을 위한 모델 예측 전류 제어 기법에 관한 연구

노찬,최종수,곽상신,김경환 한국해양환경·에너지학회 2020 한국해양환경·에너지학회지 Vol.23 No.1

The control using the power converter for wave power generation has been recently studied because it can obtain a fast dynamic response. However, it is difficult to get a transient response because of the energy characteristic of the wave energy that the conventional pulse-width modulation (PWM) method based on proportional integral control (PI-Control) for controlling the power converter has been widely used. Instead of using the optimal switching state during each sampling step, the control is performed by using various switching states located near the reference voltage vector, so that the reference current can not follow in a short time when the transient state occurs. Therefore, in this paper, Model Predictive Current Control (MPCC) is proposed with fast dynamic characteristics using model of power converter for wave power generation. The proposed method predicts the current of the next step through the model of the power converter, constructs the cost function using the predicted current and the reference current, and selects one optimal switching state during each sampling step. As in the conventional method, instead of using various switching states for each sampling, a fast transient response can be obtained because only one optimal voltage vector is used, that is, the optimal switching state, which is closest to the reference voltage vector. To verify the performance of the proposed method, the simulation is performed through the PSIM and the conventional PI-based PWM method (PI-PWM) and the proposed method demonstrate the performance of the proposed method through comparison of steady state and various transient states. 전력변환장치를 이용한 제어는 빠른 응답을 얻을 수 있기 때문에 최근에 연구가 많이 되고 있다. 하지만 기존에 파력발전용 전력변환장치 제어를 위한 비례적분제어(Proportional Integral control, PI-Control) 기반의 펄스폭변조기법(Pulse Width Modulation, PWM)은 입력 에너지가 수초단위로 변화하는 파랑에너지 특성상 빠른 과도 응답을 얻기가 어렵다. 매 샘플링 스텝마다 최적의 스위칭 상태를 사용하는 것이 아니라 기준 전압 벡터 인근에 위치한 다양한 스위칭 상태를 이용해서 제어하기 때문에 과도 상태가 발생 했을 때 기준 전류를 빠른 시간 안에 추종할 수 없게 한다. 그래서 본 논문에서는 파력발전용 전력변환장치의 모델을 이용한 전류예측제어(Model Predictive Current Control, MPCC)를 통해 빠른 동특성을 갖는 최적제어기법을 제안한다. 제안하는 방법은 전력변환장치의 모델을 통한 다음 스텝의 전류를 예측하고, 예측된 전류와 기준 전류를 이용해 비용 함수(Cost Function)을 구성한 다음 매 샘플링 스텝마다 최적의 스위칭 상태 하나를 선택한다. 기존의 방법처럼 매 샘플링 마다 다양한 스위칭 상태를 사용하는 것이 아닌 기준 전압 벡터와 가장 인접한 최적의 전압 벡터 즉 최적의 스위칭 상태 하나만 사용하기 때문에 빠른 과도 응답을 얻을 수 있다. 제안하는 방법의 제어기 성능을 검증하기 위해 PSIM을 이용해 시뮬레이션을 진행하였고, 기존의 PI기반의 PWM방법(PI-PWM)과 제안하는 방법을 정상상태와 다양한 과도상태 비교 분석을 통해 제안하는 방법의 성능을 입증한다.

비례 방향제어밸브의 동특성 개선에 관한 연구

오동훈(D. H. Oh),이일영(I. Y. Lee) 유공압건설기계학회 2013 유공압건설기계학회 학술대회논문집 Vol.2013 No.6

This paper studies on the dynamic characteristics of proportional directional control valve. An experimental apparatus including hydraulic pump, analog amplifier card, linear variable differential transformer(LVDT) and data aquisition system was set up. In order to improve the dynamic characteristics of proportional directional control valve, feed-forward controller, modified PI-D controller and input shaping filter were applied. Based on experimental results, it was confirmed that step response and frequency response of the proportional directional control valve can be improved largely by adopting the input shaping filter

비례유량제어밸브 위치제어기 자동조정

정규홍(G. H. Jung) 유공압건설기계학회 2012 유공압건설기계학회 학술대회논문집 Vol.2012 No.6

Proportional solenoid valves are modulating type which can control the displacement of valve continuously by means of electromagnetic force that is proportional to solenoid coil current. Since the solenoid type modulating valves have the advantages of fast response and compact design over air-operated or motor-operated valves, they have been gaining acceptance in chemical or power plant to control the flow of fluids such as water, steam and gas. This paper deals with an auto tuning of position controller that can provides the proportional and integral gain automatically base on the dynamic system identification. A process characteristics of the solenoid valve is estimated with critical gain and critical period at stability limit which is implemented relay feedback and controller parameters are determined by the classical Ziegler-Nichols design method. Auto tuning algorithm was verified with experiments and the effects of operating point at which relay control is activated as well as relay amplitude are investigated.

유도전동기 속도제어를 위한 비선형 비례적분 제어기 설계

오태석(Oh Tae Seok),김일환(Kim Il Hwan),박찬원(Park Chan Won) 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.1

This paper presents a robust speed control method of induction motors(IM) using a Non-linear PI controller(NPI). NPI is high gain controller in region of small error, and low gain controller in region of large error. So in steady state, system will be robust against variation of load torque. The simulation and experiment results confirm the validity of proposed control scheme.

유도전동기 속도제어를 위한 비선형 비례적분 제어기 설계

오태석,김일환,박찬원 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

This paper presents a robust speed control method of induction motors(IM) using a Non-linear PI controller(NPI). NPI is high gain controller in region of small error, and low gain controller in region of large error. So in steady state, system will be robust against variation of load torque. The simulation and experiment results confirm the validity of proposed control scheme.

IMV를 이용한 굴착기 작업장치 제어 알고리즘 개발

정규홍(G. H. Jung) 유공압건설기계학회 2019 유공압건설기계학회 학술대회논문집 Vol.2019 No.11

IMV is a combination of four 2-way valve system which replaces a conventional 4-way spool valve for the purpose of improving efficiency mostly in excavator hydraulics. As the environmental regulation for construction equipments has been tightened up, some of the overseas advanced companies have released commercial excavators of which MCV is implemented with IMVs. Development of IMV type MCV relies on the control algorithm as well as the robust performance of proportional flow control valves. In this research, IMV controller is designed and verified with experiments for excavator working unit, which determines the IMV mode of operation and the amount of valve opening in consideration of load conditions on hydraulic actuators. Firstly, the open-loop controller is designed with joystick command vs. PSV reference current map which is composed of several control parameters in order to compensate for the different flow characteristics and non-linearities of 2-way flow control valves. Secondly, the closed-loop controller is designed with PI control which is fed by actuator displacement and outputs actuator percent effort equivalent to operator’s joystick command. Experimental results show control performance and suggest the future works to be done for technical progress.

강화신호를 이용한 건물공조시스템의 최적제어에 관한 연구

조성환,양성희,양훈철 대한설비공학회 2004 설비공학 논문집 Vol.16 No.11

Technology on the proportional integral (PI) control have grown rapidly owing to the needs for the robust capacity of the controllers from industrial building sectors. However, PI controller requires tuning of gains for optimal control when the outside weather condition changes. The present study presents the possibility of reinforcement learning (RL) control algorithm with PI controller adapted in the HVAC system. The optimal design criteria of RL controller was proposed in the Environment Chamber experiment and a theoretical analysis was also conducted using TRNSYS program.