2. Demonstration of Control loop circuit project
As regular push-starting, braking, rotating direction of the transition process, the transition time to be greatly affected productivity and make full use of the motor Shock, so that the transition process shortest possible time is to improve the productivity of effective measures. To this end, you must use double-loop system. Double closed-loop speed control system means controlled feedback loop uses two links, by the speed of negative feedback as Outer Ring, coupled with current feedback system for the inner ring, Speed negative feedback signal with a speed regulator to control(ASR). Current negative feedback signals by curent regulator(ACR) to deal with. Speed feedback role is to maintain a constant speed. When the speed regulator(ASR) adopt proportional-integral (PI) form and amplifier static Magnification great, basically can eliminates the static electrical brachistochrone, no steady-state error adjust, improve electrical characteristics of the mechanical hardness. Current negative feedback’s effection is to limit the current maximum. and the Start and Brake under in line of the maximum, as well as the Central interference play inhibition ,improve the system of rapid and anti-jamming capability, allowing the system to easily stability.

2.1 SCR-Motor (KZ2D) system comparison
In KZ2D rapid reversible adjustment system, it can be divided into a circulation system and the Non-Circulating system. circulation means not pass through load, In between the two groups SCR flow of current, it don’t do useful work, also occupy the capacity of rectifier is an additional consumption, hence there must be restrictions on circulation.
2.1.1 A Circulation System
positive Group bridge is rectifier to inverter, anti-group bridge is rectifier to inverter that the whole process would be carried out continuously. because of a small number of circulation as the basic load of silicon controlled rectifier (SCR), it can make load current across the vacant region to improve the dynamic characteristics,it can guarantee current continuous reverse, thus obtaining fast, Smooth transition process. However circulation increase silicon controlled rectifier (SCR) and transformer’s burden so that the increased capacity of and silicon controlled rectifier (SCR) and transformer. and power consumption of useless, especially for the high-power electric drive system is substantial power consumption, and for limit circulation, the loop-circuit must access to large volume, high prices’ sharing reactor, thus increasing the cost of equipment investment.
2.1.2 Logic Control Non-Circuiting System
In the Non-Circuiting system, it just need to add restriction current pulse and continuous current reactor.It can save the install equipment capacity of thyristor rectifier and transformers and reduce the cost of equipment, failure due to the change resulting from the accident rate less than a circulation system. Of course, To ensure that no circulation, it will inevitably exist for some reversing dead zone, impact of the transition process fast. and logic control Non-Circuiting system will enable a group silicon controlled rectifier (SCR) work, Logic Circuit blockade with another group of trigger pulse, make the group silicon controlled rectifier (SCR) completely blocked state, radically cut off circulation pathway. Logic control Non-Circuiting system depends on the reliability of the basic logic devices,or blockade the group pulse, or blockade anti-group pulse, it just either-or, the two groups must not be allowed to open at the same time. all these by the logic devices to control, as long as the logic devices reliable, the system will be reliable work.
2.1.3 Dislocation Non-Circuiting System
The system is using silicon controlled rectifier(SCR) trigger pulse initial phase dislocation setting to achievable, that is, two trigger pulse phase staggered far, Z + F=300° or 360°. Although the two groups have silicon controlled rectifier(SCR) trigger pulse, but when the pulse inverter group here, Its silicon controlled rectifier(SCR) components still in reverse blocking state. it is impossible to conduction, They will have no circulation. The control system is relatively simple, but such a system is a late to appear,operating limited experience, Therefore, in reality, is seldom to use.
With the research and use of unceasing improving of Logic Non-Circuiting System at home and abroad, Logical elements are increasingly high quality,thereby ensuring the reliability of the system. Therefore, The push-reversible motor speed control system on the use of logic control Non-Circulating system, as shown in Figure 2.

2.2 The control loop structure design of the main links
2.2.1 Trigger Design
Role of Trigger is producing a certain power and pulse width of the trigger signal,making silicon controlled rectifier(SCR) conduction. with the phase shifter, and the phase shift within the pulse transpose,silicon controlled rectifier(SCR) control angle so that the size can change. for each cycle in the same perspective triggered thyristor, trigger signal must to be synchronized voltage thyristor power,otherwise it will be silicon controlled rectifier(SCR) main circuit output voltage Vd become large or small, Operation of the inverter when it may even cause short-circuit accident. specific we can use synchrotron transformer to achieve.
Trigger Circuit Skeleton Diagram Shown in figure 3.
2.2.2 Curent Regulator(ACR) Design
For the current closed-loop no steady-state static error,it adopts PI regulator and dual-limiting to be good indicators of the dynamic.Curent Regulator(ACR) have four input end: Current given two, the feedback signal and the push β signal given one. Current given signal from the output of Curent Regulator(ACR), selected by electronic switch,and make Reverse input to meet current negative feedback;Vgi through 1Kl and phase inverter DX to input; pushing β signal from Non-Circulating logic controller output to prevent the positive and negative switching group caused by the current impact; Current feedback signal from the current converter.In addition, To prevent Motor crawling also setting zero speed links blockade. circuit shown in Figure 4.
2.2.3 Speed Regulator (ASR) Design
Speed Regulator (ASR) the same as Current Regulator (ACR), use PI regulator. ASR has two input signals: given signal Vgn and tachogenerator feedback signal Vfn. To prevent electromotor crawling, ASR also have a zero-speed link blockade. circuit shown in figure 5.
2.2.3 Current feedback and speed feedback design
Current feedback link to the main circuit current by a certain percentage converted into corresponding voltage as a current loop feedback signal, its polarity is positive. Measured by current transformers, the main circuit by the current transformer tested, and gain voltage on the load resistance, After a three-phase bridge rectifier and filter, it can be feedback input. Set-up in output by Regulators control , Relay transistor components and Over-Current monitoring of the links.circuit diagram shown in Figure 6. speed feedback signal from the tachogenerator (TG) . circuit shown in figure 7.

2.2.4 Zero-Speed Blockader Design
Zero-Speed Blockade is when both a given speed and rotate speed are zero, occurring signal blockade speed regulator and current regulator,prevent owing to Operational Amplifiers occur zero drift and interference caused by electrical crawling. zero-speed BlockadeR to set up on Level detection, logic and judgment and delay, the circuit is shown Figure 8, Figure 9.
2.2.5 Logic Controller Design
Logic Controller is the core of the whole system, the function of Logic Controller commands the whole system by a certain logic relation, reliability of the system depends largely on logic controller. according to the system working situation, using logic control current given doors, pulse gates in contravention of the election structure. To make the system in starting, braking, Under normal rotating direction, logic devices based on speed regulator output (Wallis) for the differential signal polarity to command logic switch, but must wait for zero-current detection device occur signal can switch,the specific logic switch request as follows :
(1) two bridge not open at the same time,under any circumstances to turn off a bridge rectifier, Another bridge can open.
(2) the major loop circuit current is cannot cancel pulse before the current still exist.
(3)after Gaining zero-current signal when change switch,it should wait 3ms silicon controlled rectifier (SCR) cut-off time before cancel the Working pulse,and wait 7ms open time to open another bridge.
(4) a logical protection, not open two bridges pulse at the same time. when inverter bridge open, we should make α from αmax start to forward lead, in other words,make β push to βmin, in this way we can prevent current impact.
(5)Swith order from the torque polarity , namely Vsr= Vgi polarity signal is given. Logic Controller is composed of level detection, logical judgment, delay circuit, logic protection, push β tache, electronic switching and so on. its circuit shown in Figure 10.

3 Realization Of The System Control
Base on the flip-flop, the current regulator, speed regulator and controller logic modules for the size of its system capacity adjustment and operation of the same. Therefore, in a laboratory we carry out simulation tests of small capacity, it can verify its design whether meet the design requirements. To validate the design to meet the design requirements, above design a small capacity simulate computer simulation debugging and running tests. in the testing process, there have been both rectified voltage amplitude inequality and the overshoot current large two issues. to both of these issues in detail Analysis,we can find : after when Trigger adjust well, access to the main circuit silicon controlled rectifier (SCR), found Vd amplitude value unequal, namely after Rectifier, the voltage amplitude value is unequal.by analysis, confirm six trigger slope not too consistent, The trigger angle cause changes, causing Vd amplitude value unequal, after fine-tune the slope of each flip-flop. make Vd waveform amplitude is basically the same. adjusting current regulator, found that current overshoot is larger, After analysis and inspection, found the nominal resistance value is not forthcoming, the resistance more than nominal value is too large, replaced the smaller resistance resistance, overshoot to cut down on volume. Therefore, in the installation and testing process, we need to strictly control the slope of each flip-flop and stringent test of current regulator for each of the nominal resistance value.
Test results show that : the design is applicable to rapidity no special requirements for the production of general machinery, and in the timeliness, reliability, economic and other aspects have unmatched superiority to conventional control system, easier adjustment and energy consumption.

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