Reconfiguration of Low Voltage Electricity at Micro Hydro Power Plant (MHP) in Andungbiru

— Electricity is a means to support community activities both in efforts to improve welfare and to encourage economic development. The National Electricity Company (PLN) as the state electricity provider has not been able to reach the electricity network in remote villages. Andungbiru Village, Tiris Subdistrict, Probolinggo Regency is one of the areas that install PLTMH (Micro Hydro Power Plants). Due to the increase in load every year, the current conditions of the PLTMH power grid in Andungbiru village experience a more even distribution of R, S, and T phases in units 1 and 2. This situation causes very large voltage drops and loss of power to the channel so it needs to be configured to reset it. Based on the results of network configuration, phase voltage R, S, and T in unit 1 is 7,9136% V, 5,9599% V, and 6,4707% V which was previously 22,3385% V, 18,0570% V, and 47,3622% V. The results of reconfiguring unit 2 networks for falling phase voltage R, S, and T are 2,6957% V, 1,4909% V, and 0,8985% V which were previously 7.3672% V, 17,2237% V, and 13,8929% V. The power loss in unit 1 after reconfiguring the network is 2873,3886 Watts which was previously 20910,9708 Watts and in unit 2 after reconfiguring the network is 221,0193 Watts which is 1749,6933 Watts. The results of network reconfiguration can reduce voltage drop and power loss in low-voltage networks and follow the standard that the maximum voltage drop is 10% of the nominal voltage of 220V

Power Plants (MHP). In Andungbiru Village, there are 2 MHP units, which area PLTMH Andungbiru unit 1 (the old MHP) which is the result of community self-help, and MHP Andungbiru unit 2 (the new MHP) which is a collaboration of PT PGN (State Gas Company) and BPP Faculty of Engineering, University of Brawijaya. The two generator units are placed side by side and operate separately with the power stated on the nameplate for unit 1 of 40 kVA, and 16 kVA for unit 2.
The condition of the Andungbiru village MHP power line based on a survey that has been conducted at this time is that the distribution line of phases R, S, and T is uneven in unit 1 and unit 2. In unit 1 there are 194 APPs with details of 42 APPs in phase R, 30 APPs in phase S, and 122 T-phase APPs. In unit 2 there are 56 APPs with details of 25 R-phase APPs, 19 S-phase APPs, and 12 T-phase APPs. This situation causes a voltage drop and power loss on the line is quite high.
As a result of the lack of support from a good electrical line, the input voltage at the customer's house has a voltage drop due to losses that occur on the side of the line [3]. Reconfiguration is one of the main applications for reducing power loss in distribution systems. By determining the optimal network distribution topology, it is possible to provide electricity to all consumers with minimal power losses [4]. The lowvoltage electricity network in the village of Andungbiru uses a radial network structure. A radial network is a network that only has one supply of electric power, if there is a disturbance there will be a "black-out" or blackout on the part that cannot be supplied [6].
To improve the conditions and situations that arise above, it is necessary to consult problems and evaluate which starts with data collection and reconfiguring again about low network voltage to reduce power losses and voltage drops.

II. METHOD
The research method used in this study in general can be seen in Figure 1. Data collection is carried out to obtain other important information related to complement the data, such as (1). Taking measurements of the voltage and current that comes out directly from the generator at a certain time that has been set (2). Conducting surveys directly by recording the load points of houses ((3). Mapping the roads and low-voltage lines that are difficult to see by satellite.
A power flow study is a study conducted to obtain information regarding the power flow or system of voltage under steady operating conditions. This information is needed to evaluate power system performance and analyze generate condition and load condition. This analysis also requires power flow information under normal and emergency conditions [2].
After the necessary data has been obtained, then from each alternative power line system has been made, then it is compared which alternative from each power line system is the best by taking into all the advantages and disadvantages of each of these alternatives, in this case especially the drop voltage from the generate side to the receive side and power losses of the system. Several steps will be taken, among others: (1). Count ing the circuit kilometers of the line to find out how much resistance is in the conductor (2). Looking for voltage drops and losses that occur at each load point by calculating the power flow (3). Making a comparison of the new electricity line with the old electricity line.

Equation of Power System
The performance equation of the electric power system can be expressed in terms of the following impedance or admittance: In impedance form :

=
(1) In the admittance form : At the bus P, the active and reactive power is expressed as : And the current at bus P is : is a positive if the current flows into the system.

Equation of Gauss-Seidel Using
The equation of the electrical power system line is : If one of the buses (Bus) instead of the Ground Bus is used as a reference, then is a column vector where the elements are the voltage difference between a bus and a reference. The bus impedance matrix is prepared using one of the buses as a reference and if the reference bus voltage is Er, then the bus voltage p is: With,

The Electrical Power that Flows into the Line
After the iterative process to find out the voltage of each bus is complete, the electrical power flows in each line can be calculated. The current flows from bus p to bus q is: The electrical power flows from bus p to bus q is: While The electrical power flows from bus q to bus p is : The power losses on the p-q line are the algebraic sum of the two power flows. The power losses in the system are the sum of all the losses that occur in each line [7].

III. RESULT
In this study, the results of electrical line reconfiguration were carried out using the Gauss-Seidel method. The electricity network at the old MHP is a radial network with the furthest km of ±2 km. There are deficiencies in the old MHP power grid which has a significant impact on the quality of the electricity supplied.

A. Data on the Old Andungbiru MHP Electrical Line
The following are the results of the single line and data bus phase R unit 1 of the old line.  The following are the results of the single line and the data for the phase bus S unit 1 of the old line.  The following are the results of the single line and the data for the phase bus T unit 1 of the old line.  The following are the results of the single line and the data for the phase bus R unit 2 of the old line.  The following are the results of the single line and the data for the phase bus S unit 2 of the old line.  The following are the results of the single line and the data for the phase bus T unit 2 of the old line.

B. New Electrical Line of Andungbiru MHP
The condition of the old Andungbiru MHP power line still has a very large drop voltage and power loss, so it needs to be reconfigured by dividing the load points equally. Changes that occur take into account the layout conditions of the load points by increasing or decreasing the load displacement of the Andungbiru MHP in units 1 and 2. The planning also takes the calculation of the pull. The following is the result of the load grouping of unit 1 and unit 2. The following table shows the load balance on unit 1 and unit 2. In table 8 it is explained that the balancing of unit 1 load which was previously the R, S, and T phase with the number of APP respectively 42, 30, and 122 becomes the number of APP respectively 65, 65, and 64. In table 9 it is explained that the balancing of unit 1 load which was previously the R, S, and T phase with the number of APP respectively 25, 19, and 12 becomes the number of APP respectively 19, 19, and 18.   The following are the results of the single line and the data for the phase bus S unit 1 of the new line.   The following are the results of the single line and the data for the phase bus T unit 1 of the new line. .  The following are the results of the single line and the data for the phase bus R unit 2 of the new line.  The following are the results of the single line and the data for the phase bus S unit 2 of the new line. .  The following are the results of the single line and the data for the phase bus T unit 2 of the new line.     Table 16 shows that the percentage of drop voltage and power loss for the new line is that the percentage of drop voltage in each phase of all units 1 and 2 has decreased below 10%. The highest power loss is still in phase T, which is 1685.2500 Watts in unit 1 and the smallest power loss is in phase T, which is 26.3967 in unit 2.
From the results of the analysis of the old and new lines then a comparison of the percentage of drop voltage and power loss of the line is carried out From table 17 it can also be seen that the quality of the line for the R, S, and T phases in all units is getting better after being reconfigured, namely below 10%. The table description shows that the power loss after being reconfigured has decreased quite well in unit 1 and unit 2. It can be seen that reconfiguring the line can reduce power loss with a decrease of 86.25% in unit 1 and 87.36% in unit 2.

IV. CONCLUSION
From the results of the analysis of network reconfiguration design calculations, the following conclusions are obtained. 1. Based on the results of the calculation of the drop voltage on the old power grid, unit 1 on all phases is still above 10% and on unit 2, the drop voltage on the S and T phases is also still above 10% except for phase R of 7.9136% V. Results of reconfiguration of units 1 and unit 2 is below 10%. While the results of the calculation of the total power loss for unit 1 and unit 2 of the old electricity network were 22660.6641 Watts with network reconfiguration repaired to 3094.4079 Watts. 2. With network reconfiguration, there is also an increase in the quality of the new electricity network which is better considering that the old electricity network has the largest voltage drop of 47.3622% and a total power loss of 22660.6641 Watts. The use of larger conductor sizes can affect the voltage drop and network losses, because the larger the conductor size, the smaller the network resistance. The result of the reconfiguration of the largest voltage drop is 7.9136% in unit 1 and 2.69% in unit 2 with a total power loss of 3094.4079 Watts.